Communication method and related apparatus

Abstract

Provided are a communication method and a related apparatus. In the method, upon acquiring a first symbol sequence to be transmitted, a baseband chip performs modulation on the basis of a third symbol sequence comprising an extended symbol and a symbol to be transmitted in the first symbol sequence to obtain (N+M) modulation symbols, and then maps the (N+M) modulation symbols to an RE to obtain a second symbol sequence. The second symbol sequence has continuous phases, and the difference between the head and tail phases is an integral multiple of 2π. The phases of a CP of an OFDM baseband signal generated by the second symbol sequence and of a signal body are continuous, and there is no phase jump. Further, a phase or frequency modulation mode, such as CPM or LFM, is used for modulation, so that a waveform having continuous phases and a constant amplitude can be obtained, and thus, a constant envelope waveform can be obtained. The method is applied to a communication device, such as an IoT device, and can simplify the structure of a transmitter, reduce transmission power consumption and prolong the standby service life.

Description

Communication method and related device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 17, 2023, with application number 202311549303.4 and application name “Communication Method and Related Device”, and claims priority to the Chinese patent application filed with the China Patent Office on November 30, 2023, with application number 202311637591.9 and application name “Communication Method and Related Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of wireless communications, and in particular to a communication method and related devices. Background Art

[0003] With the development of wireless networks and the evolution of business needs, terminal devices are becoming increasingly diverse. Some terminal devices, such as Internet of Things (IoT) nodes, are low-cost and small in size. They typically lack large-capacity batteries and therefore face the problem of short standby life.

[0004] One possible solution to improving the standby life of these terminal devices is to reduce transmit power consumption. Current proposals include directly upconverting the baseband signal to eliminate the power consumption associated with mixing operations and using a nonlinear power amplifier (PA) instead of a linear PA to further reduce transmit power consumption. However, this approach places strict waveform requirements on the user, requiring a constant envelope waveform with a peak-to-average power ratio (PAPR) of 0 decibels for data transmission.

[0005] Current cellular networks use orthogonal frequency division multiplexing (OFDM) technology. To prevent interference between OFDM symbols, a guard period (CP) is typically inserted between OFDM symbols. The CP is typically constructed by copying the signal at the end of an OFDM symbol to the beginning. This does not guarantee phase continuity between the CP and the signal following it, and thus, a constant waveform envelope. Therefore, generating a phase-continuous waveform based on OFDM technology has become a pressing technical challenge. Summary of the Invention

[0006] The present application provides a communication method and related devices, in order to combine phase or frequency modulation technology with OFDM technology to obtain a phase-continuous waveform, which is conducive to obtaining a constant envelope waveform, and then applied to communication equipment to reduce transmission power consumption.

[0007] In a first aspect, a communication method is provided. The method can be applied to a first communication device. The first communication device can be a communication device (such as a terminal device or a network device), or a component used in the communication device (such as a baseband chip, a chip system, a processor, etc.), or a logic module or software capable of implementing all or part of the functions of the communication device. This application is not limited to this.

[0008] Exemplarily, the method includes: obtaining a first symbol sequence, the first symbol sequence including N symbols to be transmitted, where N is a positive integer; obtaining a second symbol sequence based on the first symbol sequence, the symbols in the second symbol sequence being obtained by mapping (N+M) modulation symbols to resource elements (RE), the (N+M) modulation symbols being obtained based on modulating a third symbol sequence, the third symbol sequence including the N symbols to be transmitted and M extended symbols in the first symbol sequence, the M extended symbols making the phases of the (N+M) modulation symbols obtained by the modulation continuous, and the difference between the phase at the starting position and the phase at the ending position being an integer multiple of 2π, where M is an integer greater than or equal to zero; generating a first OFDM baseband signal based on the second symbol sequence, the time domain resource of the first OFDM baseband signal being an OFDM symbol.

[0009] Among them, the first symbol sequence can be a sequence composed of N symbols to be transmitted obtained by modulation. Through modulation, the binary bit "0" or "1" can be mapped to a symbol. The modulation used in this application may include, but is not limited to, pulse amplitude modulation (PAM), π / 2-binary phase shift keying (BPSK), BPSK, quadrature phase shift keying (QPSK), etc., which can achieve one-dimensional modulation. One-dimensional modulation may refer to a method of modulating in one of the three dimensions of amplitude, phase or frequency. Through one-dimensional modulation, a value in a certain dimension on the complex plane can be obtained as a result output, or in other words, a real number or a pure imaginary number output can be obtained.

[0010] The third symbol sequence may include the N symbols to be transmitted in the first symbol sequence and M extended symbols. It should be understood that the extended symbols are named for the convenience of distinguishing them from the N symbols to be transmitted and should not constitute any limitation to this application.

[0011] By adding M extended symbols to the first symbol sequence, without changing the N symbols to be transmitted and their order, the M extended symbols can be designed so that the phase of the modulated symbol sequence obtained after modulating the third symbol sequence (denoted as the fourth symbol sequence for ease of distinction and explanation) is continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π. Due to the periodicity of trigonometric functions, when the difference between the first and last phases of the fourth symbol sequence is an integer multiple of 2π, the value of its sine or cosine function is equal, that is, the starting position and the ending position of the fourth symbol sequence are also phase continuous.

[0012] Among them, the phase continuity of the fourth symbol sequence can be achieved through some currently known phase or frequency modulation methods. The difference between the phase of the starting position and the phase of the ending position of the fourth symbol sequence is an integer multiple of 2π. This can be achieved by designing M extended symbols based on the adoption of these phase or frequency modulation methods.

[0013] It can be understood that the symbols in the fourth symbol sequence are (N+M) modulation symbols, the starting position of the fourth symbol sequence is the starting position of the first symbol of the (N+M) modulation symbols included in the fourth symbol sequence, and the ending position of the fourth symbol sequence is the ending position of the last symbol of the (N+M) modulation symbols included in the fourth symbol sequence. The difference between the phases of the starting position and the ending position of the fourth symbol sequence is also the difference between the first and last phases of the (N+M) modulation symbols. It can also be said that the (N+M) modulation symbols satisfy the first and last phase self-loop, or in other words, the fourth symbol sequence satisfies the first and last phase self-loop.

[0014] The (N+M) modulation symbols in the fourth symbol sequence are mapped to RE to obtain a second symbol sequence. Therefore, the second symbol sequence is a modulation symbol mapped to RE (or mapped to a subcarrier), or in other words, the second symbol sequence is obtained by mapping the (N+M) modulation symbols in the fourth symbol sequence to RE. Since RE mapping specifically refers to frequency domain mapping, the (N+M) modulation symbols in the fourth symbol sequence can be converted to the frequency domain to complete RE mapping, so the second symbol sequence can be considered to be the representation of the (N+M) modulation symbols in the fourth symbol sequence in the frequency domain. Therefore, the fourth symbol sequence and the second symbol sequence are named only to distinguish the symbol sequences in the time domain and the frequency domain. The phases of the (N+M) modulation symbols in the fourth symbol sequence are continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π, that is, the phase of the second symbol sequence is continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π, or in other words, the second symbol sequence satisfies the head and tail phase self-loop.

[0015] It can be understood that the OFDM baseband signal includes two parts: the baseband signal body and the CP. The generation of the OFDM baseband signal includes the generation of the signal body and the generation of the CP. The first OFDM baseband signal in this application is generated based on the second symbol sequence. Among them, the signal body of the first OFDM baseband signal can be generated based on the second symbol sequence, and the CP of the first OFDM baseband signal can be obtained by copying some symbols at the end of the signal body (such as K1 modulation symbols) to its head. And the K1 modulation symbols correspond to the K1 modulation symbols at the end of the aforementioned (N+M) modulation symbols. Therefore, it can also be said that the CP of the first OFDM baseband signal is generated based on the K1 modulation symbols at the end of the (N+M) modulation symbols. It is known to those skilled in the art that the time domain resource of the CP is located at a position corresponding to the CP length before the OFDM symbol of the signal body, and the frequency domain resource of the CP is the same as the subcarrier mapped by the signal body. That is to say, the K1 modulation symbols corresponding to the CP in this application do not participate in RE mapping. In other words, the above-mentioned second symbol sequence does not include the K1 symbols used to generate the CP.

[0016] Because the second symbol sequence satisfies the self-looping of the phase at the beginning and end, the signal body of the first OFDM baseband signal generated based on the second symbol sequence also satisfies the self-looping of the phase at the beginning and end. The partial symbols at the end of the signal body are copied to the head to obtain the CP of the first OFDM baseband signal. The CP of the first OFDM baseband signal is phase-continuous with the body. Therefore, the difference between the phase at the starting position and the phase at the ending position of the (N+M) modulation symbols is an integer multiple of 2π, which can be regarded as the constraint condition for determining the M extended symbols, that is, the constraint condition for determining the third symbol sequence.

[0017] On the contrary, if the extended symbol is not added to the first symbol sequence, the modulation object is the first symbol sequence. If the first symbol sequence is directly modulated, and then RE mapping and OFDM baseband signal are generated based on the obtained modulated symbol sequence, the signal body of the obtained OFDM baseband signal may not satisfy the head-to-tail phase self-loop. Therefore, there may be a phase jump between the signal body and the CP, that is, the phase of the OFDM baseband signal is discontinuous.

[0018] It should be noted that, in some cases, the symbol sequence obtained after the first symbol sequence is modulated already satisfies phase continuity, and the phases at the beginning and end are self-circulating. In this case, no additional symbols need to be added to the first symbol sequence, that is, M can be zero, and the third symbol sequence is the same as the first symbol sequence. Of course, additional symbols can also be added to the first symbol sequence so that the phase of the second symbol sequence obtained after the third symbol sequence is modulated is continuous, and the phases at the beginning and end are self-circulating, that is, M is greater than zero, and the third symbol sequence is different from the first symbol sequence.

[0019] Based on the above technical solution, the first symbol sequence is expanded to obtain a third symbol sequence, and then modulation and RE mapping are performed based on the third symbol sequence to obtain a second symbol sequence. The second symbol sequence thus obtained can simultaneously meet the following requirements: phase continuity and self-circulation of the first and last phases. The signal body of the first OFDM baseband signal generated based on the second symbol sequence and the CP also meet phase continuity. Based on this, if the modulation technology used is a modulation technology that can maintain a constant amplitude, a waveform with continuous phase and constant envelope can be obtained. In this way, a solution for combining phase or frequency modulation technology with OFDM technology to obtain a constant envelope waveform can be implemented. Since the constant envelope waveform meets the waveform requirements of direct frequency conversion and nonlinear power amplification, communication equipment can use some more power-saving methods to transmit signals. In addition, for communication equipment (especially IoT nodes with small size and no large-capacity batteries), their standby life can be improved.

[0020] In the following text, in order to distinguish it from the CPs of other OFDM baseband signals, the CP of the first OFDM baseband signal is recorded as the first CP, and the sequence composed of modulation symbols used to generate the first CP is recorded as the first CP sequence.

[0021] In combination with the first aspect, in some possible implementations of the first aspect, the modulation includes continuous phase modulation (CPM) or linear frequency modulation (LFM).

[0022] CPM is a type of phase modulation, and LFM is a type of frequency modulation. Both CPM and LFM transmit information by changing the phase or frequency of the carrier. In other words, the amplitude of the carrier signal does not carry information. Therefore, both CPM and LFM maintain a constant amplitude and a continuous phase.

[0023] In the solution provided by this application, CPM or LFM is used to modulate the third symbol sequence, making the second symbol sequence phase continuous, and thus the first OFDM baseband signal phase continuous. Furthermore, by designing the third symbol sequence, the second symbol sequence exhibits phase self-looping at the beginning and end, thereby ensuring that the CP of the first OFDM baseband signal and the signal phase are continuous. This results in a constant envelope waveform with constant amplitude and phase continuity.

[0024] It should be noted that various modulation technologies such as minimum shift keying (MSK), Gaussian minimum shift keying (GMSK), and continuous phase frequency shift keying (CP-FSK) are all derived from CPM, and therefore can all be considered as a type of CPM and should fall within the scope of protection of this application.

[0025] It should be understood that CPM and LFM, as two possible modulation methods, should not constitute any limitation to this application. Based on the same concept, technicians of this application can also use other phase or frequency modulation methods to modulate the third symbol sequence to obtain a waveform with continuous phase and constant amplitude.

[0026] In combination with the first aspect, in some possible implementations of the first aspect, M is a positive integer, and the positions of the M extended symbols in the third symbol sequence are: before the N symbols to be transmitted, or after the N symbols to be transmitted, or continuously or discretely distributed among the N symbols to be transmitted.

[0027] Among them, M extended symbols are placed before or after N symbols to be transmitted, which means that the N symbols to be transmitted remain unchanged as a whole, and M extended symbols are inserted before their starting position or after their ending position. For example, assuming that the N symbols to be transmitted are: a1, ..., a N , M extended symbols include: a N+1 , ...a N+M , if M extended symbols are before N symbols to be transmitted, the corresponding third symbol sequence is, {a N+1 ,……,a N+M , a1,……,aN If M extended symbols are after N symbols to be transmitted, the corresponding third symbol sequence is {a1, a2, ..., a N , a N+1 ,……,a N+M}.

[0028] The M extended symbols are distributed discretely or continuously among the N symbols to be transmitted, which means that the M extended symbols are inserted into the N symbols to be transmitted. In this case, the N symbols to be transmitted are not continuous, but are filled with one or more extended symbols. For example, suppose the N symbols to be transmitted are: a1, ..., a N , M extended symbols include: a N+1 ,……,a N+M An example of a third symbol sequence in which M extended symbols are continuously distributed among N symbols to be transmitted is: {a1, a N+1 , ...a N+M , a2, ..., a N An example of a third symbol sequence in which M extended symbols are discretely distributed among N symbols to be transmitted is: {a1, a N+1 , a2, ..., a N+2 ,……,a N+M , a N}.

[0029] In summary, the present application may have multiple ways to position the M extended symbols in the third symbol sequence.

[0030] In combination with the first aspect, in certain possible implementations of the first aspect, obtaining the second symbol sequence based on the first symbol sequence includes: determining a third symbol sequence based on the first symbol sequence; generating (N+M) modulation symbols based on the third symbol sequence; and mapping the (N+M) modulation symbols to RE to obtain a second symbol sequence.

[0031] The third symbol sequence may be calculated based on the N symbols to be transmitted in the first symbol sequence and the aforementioned constraints.

[0032] The (N+M) modulation symbols may be obtained based on modulation of the third symbol sequence. The following exemplarily illustrates various possible implementations of generating the (N+M) modulation symbols based on the third symbol sequence.

[0033] A first possible implementation of generating (N+M) modulation symbols based on the third symbol sequence is to modulate the third symbol sequence to obtain (N+M) modulation symbols. That is, the third symbol sequence is directly modulated, and the obtained (N+M) modulation symbols are phase-continuous.

[0034] A second possible implementation method for generating a second symbol sequence based on the third symbol sequence is to modulate the N symbols to be transmitted and the M extended symbols in the third symbol sequence respectively to obtain N modulation symbols and M modulation symbols; insert the M modulation symbols into the N modulation symbols according to the position of the M extended symbols in the third symbol sequence, and perform phase adjustment on at least some of the N modulation symbols to obtain (M+N) phase-continuous modulation symbols. The difference between the two possible implementation methods above is that the first implementation method modulates the third symbol sequence as a whole, and the second implementation method modulates the N symbols to be transmitted and the M modulation symbols separately and then splices them together. The two implementation methods are equivalent, except for the different implementation processes.

[0035] It should be understood that the implementation methods for generating (N+M) modulation symbols based on the third symbol sequence are not limited to the two described above. For example, the third symbol sequence can also be split into more subsequences, and each subsequence is modulated separately to obtain a modulation symbol sequence. Then, based on the position of each subsequence in the third symbol sequence, the modulation symbol sequence corresponding to each subsequence is spliced ​​into a whole, and phase adjustment is performed to obtain phase-continuous (N+M) modulation symbols. By mapping the (N+M) modulation symbols to REs, the value mapped to each RE can be determined.

[0036] One possible implementation of mapping the (N+M) modulation symbols to REs is to sample the (N+M) modulation symbols in the fourth symbol sequence at a sampling rate of S (S is a positive integer) to obtain (N+M)×S time domain samples. These (N+M)×S time domain samples are converted to the frequency domain to obtain (N+M)×S frequency domain samples. RE mapping is performed on these (N+M)×S frequency domain samples to determine the frequency domain sample mapped to each RE. Each frequency domain sample can be mapped to an RE, that is, each frequency domain sample can be mapped to a subcarrier. Therefore, the value mapped to each RE is the value of the frequency domain sample corresponding to that RE. This yields the frequency domain samples mapped to the (N+M)×S REs. In other words, one representation of the second symbol sequence is (N+M)×S frequency domain samples, where each S frequency domain sample corresponds to one of the (N+M) modulation symbols in the fourth symbol sequence.

[0037] Another possible implementation of mapping the (N+M) modulation symbols onto RE is: with S (S is a positive integer) as the sampling rate, the (N+M) modulation symbols in the fourth symbol sequence are sampled to obtain (N+M)×S time domain samples, and the (N+M)×S time domain samples are extended in the time domain period to obtain (N+M)×S×Z p time domain samples, where Z pIs a positive integer, which means the number of repetitions of the period obtained after the extension of the time domain period, taking (N+M)×S time domain samples as one period, or the number of times the (N+M)×S time domain samples appear repeatedly. p Convert the time domain samples to the frequency domain to get (N+M)×S×Z p Frequency domain samples. p By mapping the frequency domain samples to REs, the frequency domain samples mapped to each RE can be determined. Each frequency domain sample can be mapped to one RE, that is, each frequency domain sample can be mapped to one subcarrier. Therefore, the value mapped to each RE is the value of the frequency domain sample corresponding to the RE. Thus, the value mapped to (N+M)×S×Z p In other words, one form of the second symbol sequence is (N+M)×S×Z p frequency domain sampling points, and each S frequency domain sampling points in each period corresponds to one modulation symbol among the (N+M) modulation symbols in the fourth symbol sequence.

[0038] In a second aspect, a communication method is provided. The method can be applied to a communication device, which can be a communication device (such as a terminal device or a network device), or a component used in the communication device (such as a baseband chip, a chip system, a processor, etc.), or a logic module or software capable of implementing all or part of the functions of the communication device. This application is not limited to this.

[0039] Exemplarily, the method includes: obtaining a first symbol sequence, which includes N symbols to be transmitted, where N is a positive integer; based on the first symbol sequence, generating a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence, the first CP sequence being K1 symbols at the end of the fourth symbol sequence, the symbols in the fourth symbol sequence being (N+M) modulated symbols obtained by modulating the third symbol sequence, the third symbol sequence including the N symbols to be transmitted and M extended symbols in the first symbol sequence, the M extended symbols making the phase of the fourth symbol sequence obtained by the modulation continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π, and M is an integer greater than or equal to zero; based on the fourth symbol sequence and the first CP sequence, generating a first OFDM baseband signal, the time domain resource of the first OFDM baseband signal being an OFDM symbol.

[0040] Among them, regarding the first symbol sequence, the third symbol sequence, the fourth symbol sequence, modulation, phase continuity, and the difference between the phase of the starting position and the phase of the ending position being an integer multiple of 2π, please refer to the relevant description in the first aspect and will not be repeated here.

[0041] Unlike the first aspect, the method provided in the second aspect can pre-generate a first CP sequence for generating the first CP, and the fourth symbol sequence and the first CP sequence can be used together to generate the first OFDM baseband signal. In this case, after the signal body of the first OFDM baseband signal is generated, there is no need to copy some symbols at the end of the signal body to the beginning of the signal body to generate the first CP. In other words, the second aspect provides a different method for generating an OFDM baseband signal than the first aspect.

[0042] Because the first CP sequence is K1 symbols at the end of the fourth symbol sequence, and the fourth symbol sequence is phase-continuous and self-looping, the first CP sequence precedes the fourth symbol sequence, ensuring phase continuity between the end position of the first CP sequence and the start position of the fourth symbol sequence. The first OFDM baseband signal generated based on the fourth symbol sequence and the first CP sequence is also phase-continuous.

[0043] Based on the above technical solution, by expanding the first symbol sequence to obtain a third symbol sequence, and then modulating the fourth symbol sequence to obtain the fourth symbol sequence, the following conditions can be met simultaneously: phase continuity, self-circulation of the first and last phases, and the end position of the first CP sequence and the starting position of the fourth symbol sequence are also phase-continuous. The first OFDM baseband signal generated based on the fourth symbol sequence and the first CP sequence also satisfies phase continuity. Based on this, if the modulation technology used is a modulation technology that can maintain a constant amplitude, a waveform with continuous phase and constant envelope can be obtained. In this way, a solution for combining phase or frequency modulation technology with OFDM technology to obtain a constant envelope waveform can be implemented. Since the constant envelope waveform meets the waveform requirements of direct frequency conversion and nonlinear power amplification, communication equipment can use some more power-saving methods to transmit signals. In addition, for communication equipment (especially IoT nodes with small size and no large-capacity batteries), their standby life can be improved.

[0044] In combination with the second aspect, in some possible implementations of the second aspect, the modulation includes CPM or LFM.

[0045] For details about CPM and LFM, please refer to the relevant descriptions about CPM or LFM in the first aspect above, which will not be repeated here.

[0046] In combination with the second aspect, in some possible implementations of the second aspect, M is a positive integer, and the positions of the M extended symbols in the third symbol sequence are: before the N symbols to be transmitted, or after the N symbols to be transmitted, or continuously or discretely distributed among the N symbols to be transmitted.

[0047] For details about the positions of the M extended symbols in the third symbol sequence, please refer to the relevant description about the positions of the M extended symbols in the third symbol sequence in the first aspect above, which will not be repeated here.

[0048] In combination with the second aspect, in some possible implementations of the second aspect, generating a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the first symbol sequence includes: determining a third symbol sequence based on the first symbol sequence; and generating a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the third symbol sequence.

[0049] The third symbol sequence may be calculated based on the N symbols to be transmitted in the first symbol sequence and the aforementioned constraints.

[0050] Furthermore, the following exemplifies various possible implementations of generating a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the third symbol sequence.

[0051] A first possible implementation method for generating a fourth symbol sequence and a first CP sequence preceding the fourth symbol sequence based on the third symbol sequence is to modulate the third symbol sequence to obtain a fourth symbol sequence; and add K1 modulation symbols at the end of the fourth symbol sequence to the front of the fourth symbol sequence to obtain the fourth symbol sequence and the first CP sequence preceding the fourth symbol sequence.

[0052] That is, after the third symbol sequence is modulated to obtain the fourth symbol sequence, K1 modulation symbols at the end of the fourth symbol sequence are used as the first CP sequence and added to the beginning of the fourth symbol sequence.

[0053] A second possible implementation manner for generating the fourth symbol sequence and the first CP sequence preceding the fourth symbol sequence based on the third symbol sequence is to add K1 symbols at the end of the third symbol sequence to the beginning of the third symbol sequence to obtain a fifth symbol sequence; and modulate the fifth symbol sequence to obtain the fourth symbol sequence and the first CP sequence preceding the fourth symbol sequence. The K1 symbols at the end of the third symbol sequence are used to generate the first CP sequence.

[0054] That is to say, the third symbol sequence is first added with symbols that can be used to generate the first CP sequence, and then modulated. It should be noted that in this implementation, the fourth symbol sequence and the first CP sequence are generated by modulating the fifth symbol sequence as a whole, thereby ensuring that the phase continuity between the modulated fifth symbol sequence and the first CP sequence is achieved. Among them, the fourth symbol sequence is the modulation symbol corresponding to the third symbol sequence after modulation, and the first CP sequence is the modulation symbol corresponding to the K1 symbols at the end of the third symbol sequence after modulation. Therefore, the fourth symbol sequence can also be said to be obtained based on the modulation of the third symbol sequence.

[0055] A third possible implementation method for generating a fourth symbol sequence and a first CP sequence preceding the fourth symbol sequence based on the third symbol sequence is to modulate the N to-be-transmitted symbols and the M extended symbols in the third symbol sequence, respectively, to obtain N modulation symbols and M modulation symbols; according to the positions of the M extended symbols in the third symbol sequence, the M modulation symbols are inserted into the N modulation symbols, and the phase of at least part of the N modulation symbols is adjusted so that the phase of the (M+N) modulation symbols after the insertion of the M modulation symbols is continuous; the K1 modulation symbols at the end of the (M+N) modulation symbols are added before the (M+N) modulation symbols to obtain the fourth symbol sequence and the first CP sequence preceding the fourth symbol sequence.

[0056] The (M+N) modulation symbols constitute the fourth symbol sequence. In this implementation, the N symbols to be transmitted and the M modulation symbols are modulated separately to obtain the fourth symbol sequence, and then the first CP sequence is added. Since the third symbol sequence includes N symbols to be transmitted and M modulation symbols, modulating the N symbols to be transmitted and the M modulation symbols separately and then concatenating them is equivalent to modulating the entire third symbol sequence, but the implementation process is different.

[0057] The above method can produce a phase-continuous OFDM baseband signal over a single OFDM symbol. Since the first communication device may also transmit data over multiple consecutive OFDM symbols, the first OFDM baseband signal can be further designed to achieve phase continuity between OFDM symbols. For ease of understanding, the following description introduces a second OFDM baseband signal.

[0058] In combination with the second aspect, in some possible implementations of the second aspect, the phase difference between the starting position of the first OFDM baseband signal and the phase of the ending position of the second OFDM baseband signal is an integer multiple of 2π, the time domain resources of the second OFDM baseband signal are adjacent to the time domain resources of the first OFDM baseband signal, and the time domain resources of the second OFDM baseband signal are before the time domain resources of the first OFDM baseband signal, and the time domain resources of the second OFDM baseband signal are one OFDM symbol.

[0059] In other words, the second OFDM baseband signal is scheduled for transmission on an OFDM symbol preceding the OFDM symbol of the first OFDM baseband signal. In other words, the time domain resource of the first OFDM baseband signal is the first OFDM symbol, the time domain resource of the second OFDM baseband signal is the second OFDM symbol, the second OFDM symbol is immediately adjacent to the first OFDM symbol, and the second OFDM symbol precedes the first OFDM symbol.

[0060] The second OFDM baseband signal may be a signal generated based on the method provided in this application, or a signal generated based on existing OFDM technology, and this application does not limit this.

[0061] To ensure phase continuity between the first and second OFDM baseband signals, one possible design is to perform phase compensation on the first OFDM baseband signal so that the difference between the phase at its starting position and the phase at the ending position of the second OFDM baseband signal is an integer multiple of 2π. In other words, the phase of the OFDM baseband signal in the subsequent OFDM symbol is compensated so that the difference between the phase at its starting position and the phase at the ending position of the OFDM baseband signal in the previous OFDM symbol is an integer multiple of 2π.

[0062] For example, it is assumed that the phase of the end position of the second OFDM baseband signal is recorded as The initial phase of the first OFDM baseband signal before phase compensation is The phase compensation amount satisfy: k1 is an integer.

[0063] Based on the aforementioned second implementation of generating a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the third symbol sequence, a possible implementation of phase compensation for the first OFDM baseband signal is to adjust the initial phase of the modulation so that the adjusted initial phase Compared with the initial phase before adjustment satisfy:

[0064] Based on the aforementioned various implementations of generating a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the third symbol sequence, a possible implementation of performing phase compensation on the first OFDM baseband signal is to: Phase compensation is performed on each modulation symbol in the generated fourth symbol sequence and the first CP sequence, and the fourth symbol sequence and the first CP sequence used to generate the first OFDM baseband signal are the fourth symbol sequence after phase compensation and the first CP sequence after phase compensation.

[0065] To ensure phase continuity across different OFDM symbols, another possible design is to add extension symbols and symbols used to generate their respective CP sequences to the symbol sequences scheduled for transmission over multiple consecutive OFDM symbols. These symbols are then concatenated into a single symbol sequence in the chronological order of the OFDM symbols. The concatenated symbol sequence is then modulated to obtain a modulated symbol sequence and CP sequence corresponding to each OFDM symbol. This ensures phase continuity across the OFDM baseband signals across the OFDM symbols.

[0066] In combination with the first aspect or the second aspect, in some possible implementations, the modulation is CPM, and the M satisfies: 1≤M≤max{U+2, U+V-1}; wherein, the V satisfies: h=W / V, and W / V is the simplest fraction, the h is the modulation index of the CPM, the U is a predefined value, and the W, the U, and the V are positive integers.

[0067] In combination with the first aspect or the second aspect, in some possible implementations, the modulation is LFM, and M satisfies: 1≤M≤3.

[0068] Different numbers of extended symbols, M, can result in different spectral efficiencies and varying degrees of spectral leakage. A large M may result in low spectral efficiency but minimal spectral leakage; a small M may result in high spectral efficiency but significant spectral leakage. Therefore, by constraining the range of M, a compromise can be achieved between spectral efficiency and spectral leakage.

[0069] It should be noted that the frequency modulated signal obtained by LFM is a chirp signal, so it can be regarded as the case where U = 1 and V = 1. In other words, when the modulation method is LFM, it can also be considered that M satisfies: 1≤M≤max{U+2,U+V-1} and is an integer.

[0070] In combination with the first aspect or the second aspect, in some possible implementations, the time domain resources of the first OFDM baseband signal are adjacent to the time domain resources of the second OFDM baseband signal, and the time domain resources of the second OFDM baseband signal are before the time domain resources of the first OFDM baseband signal, and the time domain resources of the second OFDM baseband signal are one OFDM symbol; the second OFDM baseband signal is generated based on a fifth symbol sequence, and the fifth symbol sequence is modulated based on a sixth symbol sequence, and the sixth symbol sequence includes P symbols to be transmitted and Q extended symbols, Q1 extended symbols of the Q extended symbols are in the first (P+Q-K2) symbols in the sixth symbol sequence, and Q2 extended symbols of the Q extended symbols are in the last K2 symbols in the sixth symbol sequence, and it satisfies that if the modulation is performed on the first (P+Q-K2) symbols, the difference between the phase of the end position and the phase of the starting position of the obtained modulated symbol sequence is an integer of 2π. multiples, and if the modulation is performed on the last K2 symbols, the difference between the phase at the end position and the phase at the starting position of the obtained modulation symbol sequence is also an integer multiple of 2π; wherein P is a positive integer, Q, Q1 and Q2 are all integers greater than or equal to 0, and K2 is an integer greater than 1; and M is an integer greater than or equal to 0, M1 of the M extended symbols are located within the first (N+M-K1) symbols in the third symbol sequence, and M2 of the M extended symbols are located within the last K1 symbols in the third symbol sequence, and it satisfies: if the modulation is performed on the first (N+M-K1) symbols, the difference between the phase at the end position and the phase at the starting position of the obtained modulation symbol sequence is an integer multiple of 2π, and the difference between the initial phase of the modulation of the first OFDM baseband signal and the initial phase of the modulation of the second OFDM baseband signal is an integer multiple of 2π; wherein M=M1+M2, M1 and M2 are both integers greater than or equal to 0, and K1 is an integer greater than 1.

[0071] That is, if the second OFDM baseband signal and the first OFDM baseband signal satisfy their respective constraints at the same time, phase continuity between OFDM symbols can be achieved by controlling the initial phase.

[0072] The second OFDM baseband signal may also be generated based on the method for generating the first OFDM baseband signal provided in the first or second aspect. The fifth symbol sequence may correspond to the fourth symbol sequence in the first or second aspect.

[0073] Taking the first OFDM baseband signal as an example, M extended symbols are discretely distributed in the third symbol sequence. If the third symbol sequence is divided into two parts, one part includes symbols used to generate the first CP, and the remaining symbols constitute the other part. Each part of the M extended symbols includes at least one extended symbol. The presence of one or more extended symbols in each part ensures that the first and last phases of the third symbol sequence are self-circulated after modulation.

[0074] It can be understood that in the third symbol sequence, the last K1 symbols are symbols used to generate the first CP, forming one of the two parts described above, and the first (N+M-K1) symbols forming the other part. Since the first (N+M-K1) symbols are modulated, the difference between the phase at the end position and the phase at the start position of the resulting modulation symbol sequence (i.e., comprising (N+M-K1) modulation symbols) is an integer multiple of 2π. Furthermore, since CPM inherently accumulates phases, each modulation symbol obtained by LFM returns to its initial phase. Therefore, in the fourth symbol sequence obtained by performing CPM or LFM on the third symbol sequence, the end position of the (N+M-K1) modulation symbols in the first part and the starting position of the K1 modulation symbols in the second part are phase-continuous. Consequently, the difference between the phase at the start position of the K1 modulation symbols in the second part and the starting position of the (N+M-K1) modulation symbols in the first part is also an integer multiple of 2π. That is, after the third symbol sequence is divided into two parts, each part satisfies the head-to-tail phase self-loop, and this characteristic can be called double head-to-tail phase self-loop.

[0075] Similar to the first OFDM baseband signal, Q extended symbols are discretely distributed in the sixth symbol sequence. If the sixth symbol sequence is divided into two parts, one part includes symbols used to generate the second CP, and the remaining symbols are the other part. The second CP is the CP of the second OFDM baseband signal. In the sixth symbol sequence, the symbols used to generate the second CP are the K2 symbols at the end of the sixth symbol sequence. The K2 symbols at the end of the sixth symbol sequence can be modulated to obtain the K2 modulated symbols at the end of the fifth symbol sequence. The Q extended symbols include at least one extended symbol in each part. Due to the presence of one or more extended symbols in each part, each part can satisfy the first and last phase self-loop after the sixth symbol sequence is modulated.

[0076] The time domain resources of the first OFDM baseband signal are located after the time domain resources of the second OFDM baseband signal. Assuming that the second OFDM baseband signal is generated based on the fifth symbol sequence, that is, it is necessary to ensure that the phase difference between the starting position of the K1 modulation symbols at the end of the fourth symbol sequence and the phase difference between the ending position of the modulation symbol of the CP (hereinafter referred to as the second CP) used to generate the second OFDM baseband signal is an integer multiple of 2π, and the phase difference between the ending position of the K2 modulation symbols used to generate the second CP and the phase difference between the starting position of the fifth symbol sequence is an integer multiple of 2π. Therefore, as long as the phase difference between the starting position of the above-mentioned K1 modulation symbols and the starting position of the fifth symbol sequence is an integer multiple of 2π, that is, as long as the phase difference between the starting position of the fourth symbol sequence and the starting position of the fifth symbol sequence is an integer multiple of 2π.

[0077] Since the phases of the starting position of the fourth symbol sequence and the starting position of the fifth symbol sequence can both be controlled by the initial phase of the modulation, the phase difference between the two can be controlled to be an integer multiple of 2π, so that the phase continuity of the first OFDM baseband signal and the second OFDM baseband signal can be achieved.

[0078] Furthermore, the following possible implementations can be used to achieve a compromise between spectrum efficiency and spectrum leakage while satisfying the dual head-to-tail phase self-circulation.

[0079] Optionally, the modulation is CPM, M1 satisfies: 1≤M1≤max{U+2, U+V-1} and is an integer, M2 satisfies: 1≤M2≤max{U+2, U+V-1} and is an integer, M satisfies: 2≤M≤2×max{U+2, U+V-1} and is an integer; Q1 satisfies: 1≤Q1≤max{U+2, U+V-1} and is an integer, Q2 satisfies: 1≤Q2≤max{U+2, U+V-1} and is an integer, Q satisfies: 2≤Q≤2×max{U+2, U+V-1} and is an integer.

[0080] Optionally, the modulation mode is LFM, M1 satisfies: 1≤M1≤3 and is an integer, M2 satisfies: 1≤M2≤3 and is an integer, M satisfies: 2≤M≤6; Q1 satisfies: 1≤Q1≤3 and is an integer, Q2 satisfies: 1≤Q2≤3 and is an integer, and Q satisfies: 2≤Q≤6.

[0081] It can be seen that the value range of M in the above text is obtained by superimposing the ranges of M1 and M2, and the value range of Q is obtained by superimposing the ranges of Q1 and Q2. The ranges of M1, M2, Q1 and Q2 are determined based on the ranges [1, max{U+2, U+V-1}] and [1, 3] provided in the previous text respectively.

[0082] In another design, the value ranges of M and Q can also be directly defined as: 1≤M≤max{U+2, U+V-1}, which are integers; 1≤Q≤max{U+2, U+V-1}, which are integers.

[0083] In combination with the first aspect or the second aspect, in some possible implementations, the method further includes: sending a first OFDM baseband signal.

[0084] As mentioned above, in the method provided in the first aspect or the second aspect, the first communication device can be a communication device such as a terminal device, a network device, or a component configured in the communication device, such as a baseband chip, a chip system, a processor, etc.

[0085] For a baseband chip used to implement the method in the first aspect or the second aspect, or a chip system, processor, etc. used to implement a baseband processing function, sending the first OFDM baseband signal includes: outputting the first OFDM baseband signal.

[0086] Outputting the first OFDM baseband signal may specifically refer to the first OFDM baseband signal being communicated between interfaces within the communication device, such as being output by the baseband chip and input to the RF chip, so that the communication device can perform RF segment processing and signal transmission.

[0087] For a communication device used to implement the method in the first aspect or the second aspect, or a chip system used for the communication device, sending the first OFDM baseband signal includes: outputting a bandpass signal based on the first OFDM baseband signal; power amplifying the bandpass signal to obtain a power-amplified bandpass signal; and sending the power-amplified bandpass signal.

[0088] That is, the first OFDM baseband signal can be processed by up-conversion, power amplification, etc. to obtain a power-amplified bandpass signal, which is then transmitted through the antenna. In other words, the first OFDM baseband signal is transmitted on the power-amplified bandpass signal.

[0089] In combination with the first aspect or the second aspect, in some possible implementations, the method further includes: sending a reference signal, the time domain resources of the reference signal being one or more OFDM symbols, and the time domain resources of the reference signal being different from the time domain resources of the first OFDM baseband signal.

[0090] To ensure that the (N+M) modulation symbols can be properly demodulated to obtain the first symbol sequence, and to account for channel measurement requirements, the first communications device must also transmit a reference signal. To maintain phase continuity, the first communications device cannot insert reference signals at specific frequency domain locations. Therefore, a time-domain reference signal is used, carried on one or more OFDM symbols for transmission.

[0091] The time domain resource of the reference signal is different from the time domain resource of the first OFDM baseband signal. In other words, the time domain resource of the reference signal is different from the time domain resource of the data signal. For example, the time domain resource of the first OFDM baseband signal is an OFDM symbol, and the time domain resource of the reference signal may be one or more OFDM symbols adjacent to the OFDM symbol.

[0092] Optionally, a bandwidth covered by the frequency domain resources of the reference signal at least partially overlaps with a bandwidth covered by the frequency domain resources of the first OFDM baseband signal.

[0093] It should be understood that the signal body of the first OFDM baseband signal and the CP occupy the same frequency domain resources. Therefore, the frequency domain resources of the first OFDM baseband signal are also the frequency domain resources of the second symbol sequence described in the first aspect, that is, the subcarrier corresponding to the RE mapping.

[0094] The frequency band covered by the frequency domain resources of the reference signal overlaps with the target frequency band. There may be the following possible situations: the frequency domain resources of the reference signal overlap with the frequency domain resources of the first OFDM baseband signal, or the frequency domain resources of the reference signal do not overlap with the frequency domain resources of the first OFDM baseband signal, but the frequency bands covered by the two overlap.

[0095] The frequency band covered by the frequency domain resources can be understood as follows: if the frequency domain resources are continuous, then the frequency band covered by the frequency domain resources is the frequency band occupied by the frequency domain resources; if the frequency domain resources are non-continuous, such as comb-shaped, then the frequency band covered by the frequency domain resources can be the frequency band occupied by the first subcarrier to the last subcarrier of the frequency domain resources.

[0096] The bandwidth covered by the frequency domain resources of the reference signal at least partially overlaps with the bandwidth covered by the frequency domain resources of the first OFDM baseband signal, which can make the estimation and measurement of the channel based on the reference signal more accurate and more conducive to the correct demodulation of the first OFDM baseband signal.

[0097] One possible design is that the frequency domain resources of the reference signal are the same as the frequency domain resources of the first OFDM baseband signal.

[0098] That is, the frequency domain resources of the reference signal and the frequency domain resources of the first OFDM baseband signal are located in the same location and have the same size, and the two completely overlap. This allows for full channel measurement of the frequency domain resources used to transmit the first OFDM baseband signal, further facilitating the correct demodulation of the second symbol sequence.

[0099] Exemplarily, the first communication device is a terminal device, and the reference signal is an uplink reference signal.

[0100] Exemplarily, the first communication device is a network device, and the reference signal is a downlink reference signal.

[0101] In a third aspect, a communication method is provided. The method can be applied to a second communication device. The second communication device can be a communication device (such as a terminal device or a network device), or a component configured in the communication device (such as a baseband chip, a chip system, a processor, etc.), or a logic module or software capable of implementing all or part of the functions of the communication device. This application is not limited to this.

[0102] The second communication device may be a device that communicates with the first communication device in the first aspect or the second aspect. For example, the first communication device is a terminal device, and the second communication device is also a terminal device; for another example, the first communication device is a terminal device, and the second communication device is a network device.

[0103] Exemplarily, the method includes: obtaining a first OFDM baseband signal, the time domain resource of the first OFDM baseband signal being an OFDM symbol; obtaining a fourth symbol sequence based on the first OFDM baseband signal, the fourth symbol sequence including L modulation symbols, where L is a positive integer; demodulating the fourth symbol sequence to obtain a third symbol sequence, the third symbol sequence including N first symbols and M extended symbols, where L=M+N, N is a positive integer less than or equal to L, and M is an integer greater than or equal to zero; determining the positions of the M extended symbols in the third symbol sequence and the value of M; and obtaining N first symbols from the third symbol sequence.

[0104] It should be understood that the N first symbols in the third aspect may correspond to the N symbols to be transmitted in the first aspect or the second aspect. Since the symbols to be transmitted are relative to the device serving as the transmitting end, for the device serving as the receiving end, the received symbols are symbols that have already been transmitted, so they are distinguished and named as first symbols.

[0105] Corresponding to the processing process of the first aspect or the second aspect, the first OFDM baseband signal can be a baseband signal obtained by the second communication device after down-conversion and other processing of the passband signal received from the first communication device. A fourth symbol sequence can be obtained based on the first OFDM baseband signal. The fourth symbol sequence may include L (i.e., (M+N)) modulation symbols, and the L modulation symbols are demodulated to obtain a third symbol sequence including N first symbols and M extended symbols. The second communication device can remove the M extended symbols from the third symbol sequence based on M and the positions of the M extended symbols in the third symbol sequence, thereby obtaining N first symbols. The symbol sequence composed of the N first symbols may correspond to the first symbol sequence in the first aspect.

[0106] Based on the above technical solution, although the first communication device expands the first symbol sequence to be transmitted after obtaining it, and modulates it after adding M expanded symbols to obtain the third symbol sequence, after the second communication device obtains the fourth symbol sequence from the first OFDM baseband signal, it can still obtain N first symbols from the third symbol sequence based on the positions of the M expanded symbols in the third symbol sequence and the value of M. Therefore, the addition of M expanded symbols does not affect the correct demodulation of the first OFDM baseband signal. Moreover, from the perspective of the first communication device, due to the addition of M expanded symbols, the phase of the fourth symbol sequence is continuous and satisfies the self-circulation of the first and last phases, thereby making the phase of the first OFDM baseband signal continuous, which is beneficial for the first communication device to obtain a waveform with continuous phase and constant envelope, and thus provides strong support for the first communication device to transmit signals in a more power-saving manner, thereby improving the standby life of the first communication device.

[0107] In combination with the third aspect, in some possible implementations of the third aspect, the demodulation includes: CPM demodulation or LFM demodulation.

[0108] The second communication device demodulates the fourth symbol sequence in a manner corresponding to the first communication device modulating the third symbol sequence. The first communication device and the second communication device may pre-negotiate the modulation and demodulation manner, or the modulation and demodulation manner may be predefined by a protocol.

[0109] It should also be understood that the demodulation of the fourth symbol sequence can be CPM demodulation or LFM demodulation corresponding to the first or second aspects, but is not limited to CPM demodulation or LFM demodulation. Based on the same concept, those skilled in the art can make simple transformations to achieve the same effect as CPM demodulation or LFM demodulation. For example, using CPM demodulation as an example, by converting phase domain demodulation to another domain and then converting back to the phase domain after demodulation is complete, CPM demodulation is essentially still performed. Such examples will not be further elaborated.

[0110] One possible case is that M is zero; another possible case is that M is a positive integer.

[0111] When M is zero, the second communication device may directly obtain the N first symbols from the third symbol sequence, without considering the positions of the M extended symbols in the third symbol sequence. In other words, it is determined that the M extended symbols do not exist in the third symbol sequence. When M is a positive integer, the second communication device may obtain the N first symbols from the third symbol sequence based on the positions of the M extended symbols in the third symbol sequence.

[0112] In combination with the third aspect, in some possible implementations of the third aspect, the position of the M extended symbols in the third symbol sequence is: before the N first symbols, or after the N first symbols, or continuously or discretely distributed among the N first symbols.

[0113] The details of the positions of the M extended symbols in the third symbol sequence can be found in the relevant description on the positions of the M extended symbols in the third symbol sequence in combination with the first aspect, and will not be repeated here.

[0114] In combination with the third aspect, in some possible implementations, the demodulation is CPM demodulation, and the M satisfies: 1≤M≤max{U+2, U+V-1}, or, 2≤M≤2×max{U+2, U+V-1}; wherein, the V satisfies: h=W / V, and W / V is the simplest fraction, the h is the modulation index of the CPM, the U is a predefined value, and the W, the U and the V are positive integers.

[0115] In combination with the third aspect, in some possible implementations, the demodulation is LFM demodulation, and M satisfies: 1≤M≤3, or 2≤M≤6.

[0116] For the description of the value range of M, please refer to the description in combination with the first aspect or the second aspect, and will not be repeated here.

[0117] In the method provided in the third aspect, the second communication device can be a communication device such as a terminal device, a network device, etc. The method in the third aspect can be executed by the second communication device, or by components in the second communication device, such as a baseband chip, a chip system, a processor, etc.

[0118] For a baseband chip or a chip system, processor, or the like used to implement the method of the third aspect, or for implementing a baseband processing function, optionally, obtaining the first OFDM baseband signal includes: a second communication device receiving the first OFDM baseband signal. For example, the first OFDM baseband signal is received from another chip system or processor in the communication device to which the second communication device belongs. For example, the other chip system includes a radio frequency chip in the communication device to which the second communication device belongs.

[0119] For the second communication device, obtaining the first OFDM baseband signal includes: receiving a passband signal from the first communication device; and obtaining the first OFDM baseband signal based on the passband signal.

[0120] The passband signal received by the second communication device may be the power-amplified passband signal sent by the first communication device in the first or second aspect. Corresponding to the processing performed by the first communication device in the first or second aspect, after receiving the passband signal, the first communication device may perform processing such as down-conversion to obtain the first OFDM baseband signal.

[0121] In combination with the third aspect, in some possible implementations of the third aspect, the method further includes: receiving a reference signal, the time domain resources of the reference signal being one or more OFDM symbols, and the time domain resources of the reference signal being different from the time domain resources of the first OFDM baseband signal.

[0122] In this application, to maintain phase continuity, the first communications device may transmit a reference signal over one or more OFDM symbols. The second communications device may receive the reference signal over these one or more OFDM symbols to perform signal demodulation or channel measurement. For details regarding the time domain resources of the reference signal, please refer to the description of the time domain resources of the reference signal in the first or second aspects above and will not be repeated here.

[0123] Optionally, a bandwidth covered by the frequency domain resources of the reference signal at least partially overlaps with a bandwidth covered by the frequency domain resources of the first OFDM baseband signal.

[0124] One possible design is that the frequency domain resources of the reference signal are the same as the frequency domain resources of the first OFDM baseband signal.

[0125] For details of the frequency domain resources of the reference signal, please refer to the relevant description of the frequency domain resources of the reference signal in the first aspect or the second aspect above, and will not be repeated here.

[0126] In conjunction with the first to third aspects, in certain possible implementations, the positions of M and M extended symbols in the third symbol sequence are predefined by a protocol, or are indicated by the first communications device to the second communications device, or are indicated by the second communications device to the first communications device. Therefore, signaling may be exchanged between the first communications device and the second communications device, and this signaling may be used to carry the fifth information and / or sixth information described below.

[0127] If the positions of M and M spread symbols in the third symbol sequence are predefined by a protocol, the second communication device may determine the positions of M and M spread symbols in the third symbol sequence according to the protocol.

[0128] If the positions of the M spread symbols in the third symbol sequence are indicated by the first communication device to the second communication device through fifth information, the second communication device may determine the positions of the M spread symbols in the third symbol sequence based on the fifth information.

[0129] Accordingly, the method further includes: the first communication device sending fifth information to the second communication device, or the second communication device receiving fifth information from the first communication device, where the fifth information is used to indicate positions of the M extended symbols in the third symbol sequence.

[0130] For example, the second communication device is a terminal device, the first communication device is a network device, and the positions of the M extended symbols in the third symbol sequence are indicated by the first communication device to the second communication device through the fifth information. In other words, the positions of the M extended symbols in the third symbol sequence are configured by the network device.

[0131] For another example, the first communication device and the second communication device are both terminal devices. The positions of the M extended symbols in the third symbol sequence are determined by the first communication device and indicated to the second communication device via fifth information. In other words, the positions of the M extended symbols in the third symbol sequence are determined by the terminal device. The second communication device can determine the positions of the M extended symbols in the third symbol sequence based on the fifth information.

[0132] If the positions of the M spread symbols in the third symbol sequence are indicated to the first communication device by the second communication device through the fifth information, the second communication device may determine the positions of the M spread symbols in the third symbol sequence by itself.

[0133] Correspondingly, the method further includes: the first communication device receives fifth information from the second communication device, or the second communication device sends fifth information to the first communication device, where the fifth information is used to indicate positions of the M extended symbols in the third symbol sequence.

[0134] For example, the second communication device is a network device and the first communication device is a terminal device. The positions of the M extended symbols in the third symbol sequence are configured by the second communication device for the first communication device via fifth information. In other words, the positions of the M extended symbols in the third symbol sequence are configured by the network device. Alternatively, the first communication device and the second communication device are both terminal devices. The positions of the M extended symbols in the third symbol sequence are determined by the second communication device and indicated to the first communication device via fifth information. In other words, the positions of the M extended symbols in the third symbol sequence are determined by the terminal device.

[0135] Similarly, if the value of M is indicated by the first communication device to the second communication device through the sixth information, the second communication device can determine M based on the sixth information.

[0136] Correspondingly, the method further includes: the first communication device sends sixth information to the second communication device, or the second communication device receives sixth information from the first communication device, where the sixth information is used to indicate M.

[0137] If M is indicated by the second communication device to the first communication device through the sixth information, the second communication device can determine M by itself.

[0138] Correspondingly, the method further includes: the first communication device receives sixth information from the second communication device, or the second communication device sends sixth information to the first communication device, where the sixth information is used to indicate M.

[0139] For relevant examples of the exchange of the sixth information between the first communication device and the second communication device, please refer to the above description of the example of the exchange of the fifth information between the two parties, which will not be repeated here.

[0140] It is understandable that either M or the position of the M extended symbols in the third symbol sequence can be predefined by the protocol, and the other can be indicated by the fifth information or the sixth information. Alternatively, the two items, M and the position of the M extended symbols in the third symbol sequence, can be determined by different devices or by the same device. In other words, the five information and the sixth information can be indicated by different devices or by the same device. If the two items, M and the position of the M extended symbols in the third symbol sequence, are indicated by the same device to another device, then the fifth information and the sixth information can be carried in the same signaling, and the sending and receiving of the fifth information and the sixth information can be combined into one step. Furthermore, the fifth information and the sixth information can be generated by joint coding, for example, the fifth information and the sixth information can be the same information element in the same signaling; or the fifth information and the sixth information can be generated by independent coding, for example, the fifth information and the sixth information can be different information elements in the same signaling.

[0141] In one example, M is predefined, and the positions of the M extended symbols in the third symbol sequence are determined by the first communication device. Accordingly, the fifth information may be information sent by the first communication device to the second communication device, and the fifth information is used to indicate the positions of the M extended symbols in the third symbol sequence. The second communication device may determine M according to a protocol and determine the positions of the M extended symbols in the third symbol sequence based on the fifth information received from the first communication device.

[0142] Optionally, the length of an OFDM symbol is determined by a subcarrier spacing, which may be predefined or configured by a network device. Therefore, there may be signaling interaction between the first communication device and the second communication device, and the signaling may be used to carry the seventh information described below.

[0143] Correspondingly, optionally, the method also includes: the first communication device receives seventh information from the second communication device, or the second communication device sends seventh information to the first communication device, where the seventh information is used to indicate the subcarrier spacing, and the subcarrier spacing is used to determine the duration of an OFDM symbol.

[0144] For example, the first communication device is a terminal device, the second communication device is a network device or a terminal device, and the second communication device indicates the subcarrier spacing to the first communication device by sending the seventh information.

[0145] Optionally, the method also includes: the first communication device sends seventh information to the second communication device, or the second communication device receives seventh information from the first communication device, where the seventh information is used to indicate the subcarrier spacing, and the subcarrier spacing is used to determine the duration of an OFDM symbol.

[0146] For example, the first communication device is a network device or a terminal device, and the second communication device is a terminal device. The first communication device can indicate the subcarrier spacing to the second communication device by sending the seventh information.

[0147] Optionally, the method further includes: the first communication device and the second communication device receiving the seventh information from the network equipment, where the seventh information is used to indicate the subcarrier spacing.

[0148] For another example, the first communication device and the second communication device are both terminal devices, and both the first communication device and the second communication device can receive the seventh information from the network device.

[0149] In combination with the first to third aspects, in some possible implementations, the frequency domain resources of the first OFDM baseband signal are (N+M)×S subcarriers. That is, the first OFDM baseband signal is transmitted on (N+M)×S subcarriers.

[0150] Each of the (N+M)×S subcarriers can be used to transmit a frequency domain sample point, and the (N+M)×S frequency domain samples transmitted by the (N+M)×S subcarriers are obtained by performing Fourier transform on the (N+M)×S time domain samples, and the (N+M)×S time domain samples are obtained by sampling the (N+M) modulation symbols, where S is a positive integer.

[0151] If the sampling rate is S (S is a positive integer), the (N+M) modulation symbols are sampled to obtain (N+M)×S time domain samples. The (N+M)×S time domain samples are converted to the frequency domain to obtain (N+M)×S frequency domain samples. The (N+M)×S frequency domain samples can be mapped to (N+M)×S subcarriers.

[0152] Combining the aforementioned time-domain and frequency-domain resources, we can see that the first OFDM baseband signal is transmitted on the (N+M)×S subcarriers within a single OFDM symbol. This is like dividing the (N+M) signals within a single OFDM symbol into (N+M)×S subsignals, each modulated on a (N+M)×S mutually orthogonal subcarrier, thus implementing OFDM.

[0153] One possible scenario is that the (N+M)×S subcarriers are consecutive subcarriers. In other words, the (N+M)×S subcarriers are numbered consecutively. The (N+M)×S frequency domain samples are mapped to consecutive (N+M)×S subcarriers for transmission.

[0154] Another possible situation is that the (N+M)×S subcarriers are in a comb-shaped shape, and the subcarrier offsets between every two adjacent comb teeth are equal. In other words, the numbering of the (N+M)×S subcarriers is discontinuous, but the (N+M)×S subcarriers are equally spaced. The subcarrier offsets between every two adjacent comb teeth are equal, that is, the offsets between every two adjacent subcarriers in the (N+M)×S subcarriers are equal, or the number of offset subcarriers is the same. For example, the subcarrier offset is denoted as Z P , Z P Is a positive integer.

[0155] It should be noted that if the (N+M)×S frequency domain samples mapped to the (N+M)×S subcarriers are converted to the time domain, it is equivalent to taking the (N+M)×S time domain samples as a period, performing a periodic extension in the time domain, and repeatedly extending the (N+M)×S time domain samples by (Z P -1) times, or in other words, the (N+M)×S time domain samples are repeated in the time domain for Z times. P , the number of time domain samples obtained is Z P ×(N+M)×S. Therefore, from the time domain, ZP This can also be referred to as the number of repetitions of the (N+M)×S time-domain samples, or the number of cycles. By mapping the (N+M)×S frequency-domain samples to the (N+M)×S subcarriers at equal intervals, the phase continuity of the (N+M) modulation symbols is ensured, resulting in a constant envelope waveform.

[0156] Optionally, the subcarrier offset Z P It is predefined by the protocol, or configured by the network device, or determined by the terminal device. Therefore, there may be signaling interaction between the first communication device and the second communication device, and the signaling can be used to carry the first information described below.

[0157] Optionally, the method further includes: the first communication device receiving first information from the second communication device, or the second communication device sending first information to the first communication device, where the first information is used to indicate the subcarrier offset Z P .

[0158] For example, the first communication device is a terminal device, the second communication device is a network device or a terminal device, and the second communication device indicates the subcarrier offset Z to the first communication device by sending the first information. P .

[0159] Optionally, the first communication device sends first information to the second communication device, or the second communication device receives first information from the first communication device, where the first information is used to indicate the subcarrier offset Z P For example, the first communication device is a network device or a terminal device, and the second communication device is a terminal device. The first communication device can indicate the subcarrier offset Z to the second communication device by sending the seventh information. P .

[0160] Optionally, the first communication device and the second communication device receive first information from the network device, where the first information is used to indicate the subcarrier offset Z P .

[0161] For example, the first communication device and the second communication device are both terminal devices, and both the first communication device and the second communication device can receive the first information from the network device.

[0162] In conjunction with the first or second aspect, in some possible implementations, the sampling rate S is predefined by a protocol, configured by a network device, or determined by a terminal device. Therefore, signaling interaction may occur between the first communication device and the second communication device, and this signaling may be used to carry the second information described below.

[0163] Optionally, the method further includes: the first communication device receiving second information from the second communication device, or the second communication device sending second information to the first communication device, where the second information is used to indicate the sampling rate S.

[0164] For example, the first communication device is a terminal device, and the second communication device is a network device or a terminal device. The second communication device can determine a sampling rate S and indicate the sampling rate S to the first communication device by sending a second message. In other words, the sampling rate S can be configured by the network device or determined by the terminal device. Optionally, the first communication device sends the second message to the second communication device, or the second communication device receives the second message from the first communication device, where the second message indicates the sampling rate S.

[0165] Optionally, the method further includes: the first communication device sending second information to the second communication device, or the second communication device receiving second information from the first communication device, where the second information is used to indicate the sampling rate S.

[0166] For example, the first communication device is a network device or a terminal device, and the second communication device is a terminal device. The first communication device can determine a sampling rate S and indicate the sampling rate S to the second communication device by sending a second message. In other words, the sampling rate S can be configured by the network device or determined by the terminal device.

[0167] Optionally, the first communication device and the second communication device receive second information from the network device, where the second information is used to indicate the sampling rate S.

[0168] For example, the first communication device and the second communication device are both terminal devices, the sampling rate S may be configured by a network device, and both the first communication device and the second communication device may receive the second information from the network device.

[0169] The sampling rate S can be used to determine the number of subcarriers included in the frequency domain resources of the first OFDM baseband signal. Therefore, by predefining the sampling rate through a protocol, configuring the sampling rate through a network device, or determining the sampling rate through a terminal device and indicating it to the device communicating with it, the first communication device and the second communication device can determine the number of subcarriers included in the frequency domain resources of the first OFDM baseband signal based on the sampling rate.

[0170] Furthermore, the frequency domain resource of the first OFDM baseband signal is configured by the network device. Therefore, there may be signaling interaction between the first communication device and the second communication device, and the signaling can be used to carry the eighth information described below.

[0171] Optionally, the method also includes: the first communication device receives eighth information from the second communication device, or the second communication device sends eighth information to the first communication device, wherein the eighth information is used to indicate the position of the frequency band allocated to the first communication device, and the position of the frequency band is used to determine the frequency domain resources of the first OFDM baseband signal.

[0172] For example, the first communication device is a terminal device, and the second communication device is a network device. The second communication device can configure the position of the frequency band allocated to the first communication device for the first communication device through the eighth information.

[0173] Optionally, the method also includes: the first communication device and the second communication device receiving eighth information from the network equipment, the eighth information being used to indicate the position of the frequency band allocated to the second communication device, and the position of the frequency band being used to determine the frequency domain resources of the first OFDM baseband signal.

[0174] For example, the first communication device and the second communication device are both terminal devices, and the network device can indicate the location of the frequency band allocated to the first communication device to the first communication device and the second communication device through the eighth information.

[0175] The frequency band may be, for example, a frequency band allocated by the network device to the first communication device (or terminal device) for data transmission. When the eighth information indicates the location of the frequency band, it may specifically indicate the center frequency and bandwidth of the frequency band, or at least two of the starting position, ending position, and bandwidth of the frequency band, which is not limited in this application.

[0176] Based on the position of the frequency band allocated to the terminal device and combined with the above-mentioned subcarrier offset, the absolute position of the (N+M)×S subcarriers can be determined, and then the subcarrier where each modulation symbol in the second symbol sequence is located can be determined.

[0177] In conjunction with the first to third aspects, in certain possible implementations, the length of the CP of the first OFDM baseband signal (i.e., the first CP) is predefined by a protocol, or configured by a network device, or configured by a terminal device. Therefore, signaling interaction may occur between the first communication device and the second communication device, and this signaling may be used to carry the third information described below.

[0178] The length of the first CP can be represented by the number of modulation symbols corresponding to the first CP. For example, in the first aspect, the modulation symbols corresponding to the first CP are K1 modulation symbols at the end of the second symbol sequence; in the second aspect, the first CP corresponds to the first CP sequence, and the first CP sequence consists of K1 modulation symbols at the end of the fourth symbol sequence. Therefore, K1 is the length of the first CP. In addition, in the second aspect, the length of the first CP is equal to the length of the first CP sequence, both being K1.

[0179] One possible scenario is that the first communication device is a terminal device, and the terminal device can use all of the allocated frequency domain resources to transmit the first OFDM baseband signal. In this case, the (N+M)×S subcarriers can occupy the entire frequency band allocated to the terminal device, including continuous or comb-shaped subcarriers. For example, if the terminal device is allocated a 10 megahertz (MHz) frequency band, the (N+M)×S subcarriers can occupy the entire 10MHz continuously, or can be distributed in a comb-shaped manner on the 10MHz frequency band.

[0180] In this case, the length of the first CP may correspond to the frequency bandwidth allocated to the terminal device. The terminal device may determine the length of the first CP based on the system bandwidth, its corresponding CP length, and the allocated frequency bandwidth. In other words, the length of the first CP is determined by the terminal device. The frequency bandwidth allocated to the terminal device may be configured or predefined by the network device, and one or more of the system bandwidth and its corresponding CP length may also be configured or predefined by the network device.

[0181] Alternatively, the length of the first CP may be configured by the network device, for example, the network device directly indicates the bandwidth of the frequency band allocated to the first communication device and the corresponding CP length to the first communication device.

[0182] Another possible scenario is that the first communication device is a terminal device, and the terminal device can use a portion of the allocated frequency domain resources (referred to as the target frequency band for ease of distinction and explanation) to transmit the first OFDM baseband signal. In this case, the (N+M)×S subcarriers can be continuous. For example, if the terminal device is allocated a 10MHz frequency band, the (N+M)×S subcarriers can continuously occupy 5MHz of it.

[0183] In this case, the length of the first CP may correspond to the frequency bandwidth actually used by the terminal device to transmit the first OFDM baseband signal. The terminal device may determine the length of the first CP based on the system bandwidth and its corresponding CP length, as well as the bandwidth of the target frequency band actually used by the terminal device. Among them, one or more of the system bandwidth and its corresponding CP length may be configured or predefined by the network device. The bandwidth of the target frequency band actually used by the terminal device may be determined by the terminal device.

[0184] In another possible scenario, the first communication device is a network device, and the network device may determine the length of the first CP based on the system bandwidth and its corresponding CP length, as well as the bandwidth of the target frequency band actually used. One or more of the system bandwidth and its corresponding CP length may be determined independently by the network device.

[0185] It should be understood that the bandwidth of the target frequency band may be less than or equal to the bandwidth allocated by the network device.

[0186] Optionally, the method further includes: the first communication device receiving third information from the second communication device, or the second communication device sending third information to the first communication device, where the third information is used to indicate the length of the first CP.

[0187] For example, the first communication device is a terminal device, and the second communication device is a network device. The length of the first CP may be configured by the network device. Therefore, the second communication device may configure the length of the CP for the first communication device through the third information.

[0188] When the third information is used to indicate the length of the first CP, for example, it may include the length information of the first CP, or include: the bandwidth of the frequency band allocated to the first communication device.

[0189] The length information of the first CP may be the number of modulation symbols included in the first CP, or information that can be used to identify the number of modulation symbols included in the first CP. That is, the third information is used to indicate K1.

[0190] The ratio of the system bandwidth to the bandwidth of the frequency band allocated to the terminal device is equal to the ratio of the CP length corresponding to the system bandwidth to the CP length corresponding to the bandwidth of the frequency band allocated to the terminal device. In other words, the ratio of the bandwidth of the frequency band allocated to the terminal device to its corresponding CP length is equal to the ratio of the system bandwidth to its corresponding CP length. Therefore, the length of the first CP can also be determined based on the system bandwidth, the CP length corresponding to the system bandwidth, and the bandwidth of the frequency band allocated to the terminal device.

[0191] For another example, the first communication device is a terminal device, and the second communication device is a network device. The length of the first CP may be determined by the terminal device. Therefore, the terminal device may indicate the length of the first CP to the network device through the third information.

[0192] When the third information is used to indicate the length of the first CP, for example, it may include the length information of the first CP, or include: the bandwidth of the target frequency band actually used by the first communication device.

[0193] The length information of the first CP may be the number of modulation symbols included in the first CP, or information that can be used to identify the number of modulation symbols included in the first CP.

[0194] The ratio of the bandwidth of the target frequency band to the system bandwidth is equal to the ratio of the length of the first CP to the length of the CP corresponding to the system bandwidth. In other words, the ratio of the target frequency band to the length of its corresponding first CP is equal to the ratio of the system bandwidth to its corresponding CP length. Therefore, the length of the first CP can also be determined based on the system bandwidth, the CP length corresponding to the system bandwidth, and the bandwidth of the target frequency band.

[0195] Optionally, the method further includes: the first communication device sending third information to the second communication device, or the second communication device receiving third information from the first communication device, where the third information is used to indicate the length of the first CP.

[0196] For example, the first communication device is a network device and the second communication device is a terminal device, and the length of the first CP may be configured by the network device. Therefore, the first communication device may configure the length of the first CP for the second communication device through the third information.

[0197] For another example, the first communication device is a terminal device, and the second communication device is a network device. The length of the first CP may be determined by the terminal device. Therefore, the terminal device may indicate the length of the first CP to the network device through the third information.

[0198] Regarding the content included in the third information, please refer to the examples above and will not be repeated here.

[0199] Optionally, the method further includes: the first communication device and the second communication device receiving third information from the network device, where the third information is used to indicate the length of the first CP.

[0200] For example, the first communication device and the second communication device are both terminal devices, and the length of the first CP may be configured by the network device. Therefore, the first communication device and the second communication device may both receive the third information from the network device.

[0201] Regarding the content included in the third information, please refer to the examples above and will not be repeated here.

[0202] In conjunction with the first to third aspects, the modulation parameters are predefined by a protocol, or determined by the first communication device, or determined by the second communication device. Therefore, signaling may be exchanged between the first and second communication devices. This signaling may be used to carry the fourth information described below, which may be used to indicate one or more of the modulation parameters.

[0203] In one example, the modulation is CPM, and the parameters of CPM include: a frequency pulse shaping function of CPM, a phase pulse shaping function of CPM, a modulation index of CPM, or an initial phase of CPM.

[0204] Among them, the frequency pulse shaping function of CPM, the phase pulse shaping function of CPM, the modulation index of CPM and the initial phase of CPM can all be determined by the first communication device or the second communication device, or can be partially determined by the first communication device and the other part determined by the second communication device, or can be partially determined by the first communication device and / or the second communication device and the other part is predefined by the protocol, or can all be predefined by the protocol, and this application does not limit this.

[0205] Optionally, the method also includes: the first communication device receives fourth information from the second communication device, or the second communication device sends fourth information to the first communication device, and the fourth information is used to indicate one or more of the following: the frequency pulse shaping function of CPM, the phase pulse shaping function of CPM, the modulation index of CPM or the initial phase of CPM.

[0206] For example, the first communication device is a terminal device, and the second communication device is a network device, and the one or more parameters mentioned above may be configured by the network device. Therefore, the first communication device may receive the fourth information from the second communication device.

[0207] Optionally, the method also includes: the first communication device sends fourth information to the second communication device, or the second communication device receives fourth information from the first communication device, and the fourth information is used to indicate one or more of the following: the frequency pulse shaping function of CPM, the phase pulse shaping function of CPM, the modulation index of CPM or the initial phase of CPM.

[0208] For example, the first communication device is a network device, the second communication device is a terminal device, and the modulation parameters may be configured by the network device. Therefore, the first communication device may send the fourth information to the second communication device.

[0209] For another example, the first communication device is a terminal device, and the second communication device is a network device or a terminal device, and the one or more parameters may be determined by the terminal device. Therefore, the first communication device may send the fourth information to the second communication device.

[0210] In another example, the modulation is LFM, and the parameters of LFM include: a chirp rate of LFM.

[0211] Optionally, the method further includes: the first communication device receiving fourth information from the second communication device, or the second communication device sending fourth information to the first communication device, where the fourth information is used to indicate a frequency modulation slope of the LFM.

[0212] Optionally, the method further includes: the first communication device sending fourth information to the second communication device, or the second communication device receiving fourth information from the first communication device, where the fourth information is used to indicate a frequency modulation slope of the LFM.

[0213] For examples of the first communication device receiving the fourth information from the second communication device and the first communication device sending the fourth information to the second communication device, please refer to the above and will not be repeated here.

[0214] In the fourth aspect, a baseband chip is provided. The baseband chip can be applied to the first communication device in the first aspect and can be used to implement the functions implemented by the first communication device in the first aspect in the baseband. Since the content of the first aspect has been described in detail above, it will not be described in detail below.

[0215] Exemplarily, the baseband chip includes: a processing circuit, which is used to obtain a first symbol sequence, wherein the first symbol sequence includes N symbols to be transmitted, where N is a positive integer; the processing circuit is also used to: obtain a second symbol sequence based on the first symbol sequence, wherein the symbols in the second symbol sequence are obtained by mapping (N+M) modulation symbols to resource elements RE, and the (N+M) modulation symbols are obtained based on modulating a third symbol sequence, wherein the third symbol sequence includes the N symbols to be transmitted and M extended symbols in the first symbol sequence, and the M extended symbols make the phase of the (N+M) modulation symbols obtained by the modulation continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π, and M is an integer greater than or equal to zero; the processing circuit is also used to: generate a first OFDM baseband signal based on the second symbol sequence, and the time domain resource of the first OFDM baseband signal is an OFDM symbol.

[0216] Optionally, the baseband chip further includes an interface circuit, which can be used to output the first OFDM baseband signal.

[0217] In the fifth aspect, a baseband chip is provided. The baseband chip can be applied to the first communication device in the second aspect and can be used to implement the functions implemented by the first communication device in the second aspect in the baseband. Since the content of the second aspect has been described in detail above, it will not be described in detail below.

[0218] Exemplarily, the baseband chip includes: a processing circuit, which is used to obtain a first symbol sequence, wherein the first symbol sequence includes N symbols to be transmitted, where N is a positive integer; the processing circuit is also used to: based on the first symbol sequence, generate a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence, wherein the first CP sequence is K1 symbols at the end of the fourth symbol sequence, and the symbols in the fourth symbol sequence are (N+M) modulated symbols obtained by modulating the third symbol sequence, and the third symbol sequence includes the N symbols to be transmitted and M extended symbols in the first symbol sequence, and the M extended symbols make the phase of the fourth symbol sequence obtained by the modulation continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π, and M is an integer greater than or equal to zero; the processing circuit is also used to: based on the fourth symbol sequence and the first CP sequence, generate a first OFDM baseband signal, and the time domain resource of the first OFDM baseband signal is an OFDM symbol.

[0219] Optionally, the baseband chip further includes an interface circuit, which can be used to output the first OFDM baseband signal.

[0220] In a sixth aspect, a chip system is provided, comprising: a radio frequency chip and the baseband chip described in the fourth or fifth aspect. The baseband chip is configured to generate a first OFDM baseband signal; the radio frequency chip is configured to obtain a bandpass signal based on the first OFDM baseband signal from the baseband chip; and is configured to power amplify the bandpass signal to obtain the power-amplified bandpass signal.

[0221] Furthermore, a transmitter is provided, comprising the aforementioned chip system.

[0222] Optionally, the transmitter further includes an antenna for transmitting the power-amplified bandpass signal.

[0223] In combination with the sixth aspect, in some possible implementations of the sixth aspect, the RF chip includes: an up-conversion module and a power amplifier, the up-conversion module being used to obtain and output a bandpass signal based on a first OFDM baseband signal from the baseband chip; the power amplifier being used to power amplify the bandpass signal to obtain a power-amplified bandpass signal.

[0224] In combination with the sixth aspect, in some possible implementations of the sixth aspect, the bandpass signal is a frequency modulated signal, and the up-conversion module is specifically used to directly frequency modulate the carrier based on the first OFDM baseband signal to obtain the frequency modulated signal.

[0225] The carrier is directly frequency modulated based on the first OFDM baseband signal, that is, the up-conversion module is controlled by the first OFDM baseband signal to generate a time-varying frequency modulation waveform, thereby eliminating the mixing operation through the mixer. In comparison, it can simplify the transmitter structure and up-conversion operation, save power consumption, and thus have lower cost and transmission power consumption.

[0226] By way of example and not limitation, the up-conversion module includes a phase-locked loop (PLL), a voltage-controlled oscillator (VCO), or a digitally controlled oscillator (DCO). It should be understood that this application is not limited to the specific components included in the up-conversion module. As long as it can generate a frequency-adjustable sine wave, the above-mentioned PLL, VCO, or DCO can also be replaced to achieve direct frequency modulation.

[0227] It should also be understood that direct frequency modulation is only one possible implementation method and does not limit the scope of protection of this application. The up-conversion module can also be used to perform a mixing operation on the first OFDM baseband signal to output a bandpass signal. In this case, the up-conversion module may include: a PLL, a VCO, or a DCO, and a mixer.

[0228] In combination with the sixth aspect, in some possible implementations of the sixth aspect, the power amplifier is a nonlinear power amplifier, and the nonlinear power amplifier can be used to perform nonlinear power amplification on a bandpass signal.

[0229] Based on this technical solution, the baseband chip can output a signal with a constant envelope waveform. Therefore, during the RF processing stage, direct frequency conversion can be used instead of mixing, and nonlinear power amplification can be used instead of linear power amplification. This not only allows for lower power consumption for signal transmission, significantly saving power and improving standby life, but also simplifies the transmitter structure, for example by removing the mixer and replacing the linear power amplifier with a nonlinear one, resulting in lower costs.

[0230] It should be understood that nonlinear amplification is only one possible implementation method and should not constitute any limitation on the scope of protection of this application. The power amplifier can also be a linear power amplifier for linearly amplifying the bandpass signal. This application does not limit this.

[0231] In a seventh aspect, a communication device is provided, which can be used to implement the functions of the first communication device in the first aspect or the second aspect. Exemplarily, the communication device may include the baseband chip described in the fourth aspect or the fifth aspect, or include the transmitter described in the sixth aspect.

[0232] Optionally, the communication device is a terminal device.

[0233] In the eighth aspect, a baseband chip is provided, which can be applied to the second communication device in the third aspect and can be used to implement the functions implemented by the second communication device in the third aspect in the baseband. Since the content of the third aspect has been described in detail above, it will not be described in detail below.

[0234] Exemplarily, the baseband chip includes: an interface circuit and a processing circuit, the interface circuit can be used to obtain a first OFDM baseband signal; the processing circuit can be used to: obtain a fourth symbol sequence based on the first OFDM baseband signal, the fourth symbol sequence including L modulation symbols, L is a positive integer; demodulate the fourth symbol sequence to obtain a third symbol sequence, the third symbol sequence including N first symbols and M extended symbols, L=M+N, N is a positive integer less than or equal to L, and M is an integer greater than or equal to zero; determine the position of the M extended symbols in the third symbol sequence and the value of M; and obtain N first symbols from the third symbol sequence.

[0235] In a ninth aspect, a chip system is provided, comprising: a radio frequency chip and the baseband chip described in the eighth aspect. The radio frequency chip is configured to output a first OFDM baseband signal based on the passband signal; and the baseband chip is configured to obtain N first symbols based on the first OFDM baseband signal.

[0236] Furthermore, this aspect also provides a receiver, comprising the aforementioned chip system.

[0237] Optionally, the receiver further includes an antenna for receiving a bandpass signal.

[0238] In a tenth aspect, a communication device is provided, which can be used to implement the function of the second communication device in the third aspect. Exemplarily, the communication device can include the baseband chip described in the eighth aspect, or the receiver described in the ninth aspect.

[0239] Optionally, the communication device is a network device.

[0240] In the eleventh aspect, a communication device is provided that can implement the communication method described in any one of the first to third aspects above. The device includes corresponding units or modules for executing the above method. The units or modules included in the device can be implemented in software and / or hardware. The communication device can be the baseband chip of the fourth or fifth aspect, or the chip system or transmitter of the sixth aspect, or the communication device of the seventh aspect, or the baseband chip of the eighth aspect, or the chip system or receiver of the ninth aspect, or the communication device of the tenth aspect.

[0241] In a twelfth aspect, a computer-readable storage medium is provided, comprising a computer program, which, when executed on a computer, executes the method in any one of the above-mentioned first to third aspects.

[0242] In the thirteenth aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instruction), which enables the method in any one of the above-mentioned first to third aspects to be executed when the computer program is run.

[0243] In a fourteenth aspect, an embodiment provides a communication system, comprising the aforementioned first communication device and second communication device.

[0244] In combination with the above aspects, in some possible implementations, the first communication device is a terminal device and the second communication device is a network device; or, the first communication device is a terminal device and the second communication device is a terminal device; or, the first communication device is a network device and the second communication device is a terminal device.

[0245] It should be understood that the fourth to fourteenth aspects of the present application correspond to the technical solutions of the first to third aspects of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0246] FIG1 is a schematic diagram of a communication system applicable to the communication method provided in an embodiment of the present application;

[0247] FIG2 is a schematic diagram of several different communication scenarios applicable to the communication method provided in an embodiment of the present application;

[0248] FIG3 is a schematic diagram of a transmitter structure currently used in terminal equipment;

[0249] FIG4 is a schematic diagram of a transmitter structure applicable to the communication method provided in an embodiment of the present application;

[0250] FIG5 is a schematic diagram of a signal processing process provided by an embodiment of the present application;

[0251] FIG6 is a schematic flow chart of a communication method provided in an embodiment of the present application;

[0252] FIG7 is a schematic diagram of a third symbol sequence provided in an embodiment of the present application;

[0253] FIG8 is a schematic diagram of generating a fourth symbol sequence based on a third symbol sequence according to an embodiment of the present application;

[0254] FIG9 is another schematic diagram of generating a fourth symbol sequence based on a third symbol sequence according to an embodiment of the present application;

[0255] FIG10 is a schematic diagram of (N+M)×S subcarriers provided in an embodiment of the present application;

[0256] FIG11 is a schematic diagram of mapping a fourth symbol sequence onto REs to obtain a second symbol sequence according to an embodiment of the present application;

[0257] FIG12A is a schematic diagram of a processing process from obtaining a first symbol sequence to sending a passband signal by a terminal device according to an embodiment of the present application;

[0258] FIG12B is another schematic diagram of the processing process of a terminal device from acquiring a first symbol sequence to sending a passband signal provided by an embodiment of the present application;

[0259] FIG13A is another schematic diagram of the processing process from obtaining the first symbol sequence to sending the passband signal of the terminal device provided by one embodiment of the present application;

[0260] FIG13B is another schematic diagram of the processing process from obtaining the first symbol sequence to sending the passband signal by the terminal device according to an embodiment of the present application;

[0261] FIG14 is a schematic diagram of a processing procedure of a network device from receiving a passband signal to obtaining a first symbol sequence according to an embodiment of the present application;

[0262] FIG15 is a schematic flow chart of a communication method provided in another embodiment of the present application;

[0263] FIG16 is a schematic diagram of generating a fourth symbol sequence and a first CP sequence based on a third symbol sequence according to another embodiment of the present application;

[0264] FIG17 is a schematic diagram of an eighth symbol sequence provided by another embodiment of the present application;

[0265] FIG18 is a schematic diagram of a processing process from obtaining a first symbol sequence to sending a passband signal by a terminal device provided by another embodiment of the present application;

[0266] FIG19 is another schematic diagram of the processing process of a terminal device from acquiring a first symbol sequence to sending a passband signal provided by another embodiment of the present application;

[0267] FIG20 is a simulation diagram provided in an embodiment of the present application;

[0268] FIG21 is a schematic diagram of time domain resources of reference signals and data signals provided in an embodiment of the present application;

[0269] FIG22 is a schematic diagram of frequency domain resources of reference signals and data signals provided in an embodiment of the present application;

[0270] FIG23 is a schematic diagram of a symbol sequence on a first OFDM symbol and a second OFDM symbol provided in an embodiment of the present application;

[0271] FIG24 is a schematic diagram of phase compensation provided by an embodiment of the present application;

[0272] FIG25 is another schematic diagram of phase compensation provided by an embodiment of the present application;

[0273] FIG26 is a schematic diagram of a process for processing multiple symbol sequences according to an embodiment of the present application;

[0274] FIG27 is a schematic flow chart of a communication method provided in yet another embodiment of the present application;

[0275] FIG28 is a schematic block diagram of a communication device provided in an embodiment of the present application;

[0276] FIG29 is a schematic block diagram of a baseband chip provided in an embodiment of the present application;

[0277] Figure 30 is a schematic block diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0278] The technical solution in this application will be described below with reference to the accompanying drawings.

[0279] To facilitate understanding of the embodiments of the present application, the following points are first explained:

[0280] First, multiple letters are used in this application to represent different parameters. For ease of understanding, a brief description of the letters used is given here.

[0281] N: the number of symbols to be transmitted in the first symbol sequence, N is a positive integer;

[0282] M: the number of extended symbols in the third symbol sequence, where M is an integer greater than or equal to zero;

[0283] K1: the length of the first CP, K1 is a positive integer;

[0284] K2: the length of the second CP, K2 is a positive integer;

[0285] S: sampling rate, S is a positive integer;

[0286] Z p : The subcarrier offset between every two adjacent subcarriers in the frequency domain resources of the second symbol sequence, Z p is a positive integer;

[0287] a: first symbol sequence, which may include N symbols to be transmitted: a1, a2, a3, ..., a N ;

[0288] a: A third symbol sequence may include N symbols to be transmitted and M extended symbols.

[0289] Second, in this application, a symbol sequence consists of one or more symbols in a certain order, and may also be referred to as a symbol block. A symbol sequence can be used to define symbols and the order between symbols. A symbol sequence in this document can be a sequence of one or more symbols (e.g., symbols to be transmitted, or symbols to be transmitted and extended) in a certain order before modulation, or a sequence of one or more modulated symbols in a certain order after modulation.

[0290] Third, in this application, two modulation operations are performed at the signal transmitting end (such as the aforementioned first communication device), namely modulation and CPM or LFM. Modulation is a one-dimensional modulation used to modulate bits into modulation symbols (such as the N to-be-transmitted symbols in the first symbol sequence in this application), and CPM or LFM is used to modulate the modulation symbols obtained by modulation onto the phase or frequency of the carrier.

[0291] Correspondingly, at the receiving end of the signal (such as the aforementioned second communication device), two demodulation operations may also be performed: demodulation corresponding to modulation and demodulation corresponding to CPM or LFM. Demodulation corresponding to CPM or LFM, which may be referred to as CPM demodulation or LFM demodulation, is used to demodulate the modulation symbol sequence from the carrier, while demodulation corresponding to modulation is used to demodulate the modulation symbol sequence obtained by CPM demodulation or LFM demodulation to obtain a bit sequence.

[0292] In this application, for the sake of ease of distinction and understanding, the symbols obtained through CPM or LFM are collectively referred to as modulation symbols, the symbols before CPM or LFM are recorded as symbols to be transmitted or extended symbols, or collectively referred to as symbols, and the symbols obtained through CPM demodulation or LFM demodulation are recorded as first symbols or extended symbols, or collectively referred to as symbols.

[0293] Fourth, in the present application, the offset may be used to represent the degree of offset between two objects, or the distance between two objects. For example, the subcarrier offset may be obtained by subtracting the numbers of two subcarriers.

[0294] Fifth, in this application, indications include direct indications (also called explicit indications) and implicit indications (also called indirect indications). Direct indication of information A refers to including information A; implicit indication of information A refers to indicating information A through the correspondence between information A and information B and direct indication of information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0295] Sixth, in this application, information C is used to determine information D, including situations where information D is determined solely based on information C, as well as situations where information D is determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0296] Seventh, for ease of understanding, this application describes the signal processing process using multiple figures. These figures are merely illustrative and should not constitute any limitation on this application. For example, the order of the steps shown in the various figures can be simply changed based on their functions and internal logic. For another example, the steps in the various figures can be executed in full or in part, as long as the same functions as in the embodiments of this application are achieved. Eighth, in this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship, but does not exclude the possibility of indicating an "and" relationship. The specific meaning of the expression should be understood in the context. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a, b, and c. A, b, and c can be single or multiple.

[0297] Ninth, in this application, prefixes such as "first" and "second" are used solely to distinguish and describe different things belonging to the same category, and do not constrain the order, size, or quantity of things. For example, "first communication device" and "second communication device" are simply different devices, and do not restrict the number of devices or their priority relationship. For another example, "first information" and "second information" are simply different pieces of information, and there is no temporal order, size, or priority relationship between the two.

[0298] Tenth, the "sending" and "receiving" in this application indicate the direction of signal transmission. For example, "sending information to a network device" can be understood as the destination end of the information being the network device, which can include direct sending through the air interface, and also includes indirect sending through the air interface by other units or modules. "Receiving information from a network device" can be understood as the source end of the information being the network device, which can include direct receiving from the network device through the air interface, and also includes indirect receiving from the network device through the air interface from other units or modules. "Sending" can also be understood as the "output" of the chip interface, and "receiving" can also be understood as the "input" of the chip interface.

[0299] In other words, sending and receiving can be carried out between devices, for example, between network devices and terminal devices; or it can be carried out within a device, for example, sending or receiving between components, modules, chips, software modules or hardware modules within the device through a bus, wiring or interface.

[0300] Eleventh, in the embodiments of the present application, "when", "if" and "if" all mean that the device will make corresponding processing under certain objective circumstances, which does not limit the time, and does not require the device to have a judgment action when it is implemented, nor does it mean that there are other limitations.

[0301] Twelfth, in this application, words such as "example," "exemplarily," "for example," or "such as" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "example," "exemplarily," "for example," or "such as" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "example," "exemplarily," "for example," or "such as" is intended to present the relevant concepts in a concrete manner.

[0302] Thirteenth, to facilitate understanding, the processing procedures of various devices are illustrated below with reference to multiple figures. For example, Figures 12A to 14, 16, 18, 19, and 24 to 26, among others. Each operation in the processing procedures illustrated in each figure can be implemented by a corresponding module. For example, modulation can be implemented by a modulation module, sampling can be implemented by a sampling module, or both modulation and sampling can be implemented by a modulation module. Another example is Fourier transform and frequency domain mapping can be implemented by an RE mapping module; or time domain period extension can be implemented by an RE mapping module. Another example is OFDM baseband signal generation can be implemented by an OFDM baseband generation module. Another example is demodulation can be implemented by a demodulation module. And so on. The specific implementation methods for each module and its corresponding operations are described above in steps 601 to 606. For more detailed descriptions, please refer to the above text and will not be repeated here. In addition, the division of each module is only a division of logical functions, and there may be other division methods in actual implementation. For example, some modules can be combined into one module, or some modules can be split into more modules, etc. This application does not limit this.

[0303] Fourteenth, the first to ninth information in this application are defined only for the purpose of distinguishing their respective functions, and should not constitute any limitation on the number of information, the number of times the information is sent, and the signaling that carries this information. In some implementations, some information (such as at least two items of the first to ninth information) can be carried in the same signaling, and implemented through one sending step (for the sender) or one receiving step (for the receiver); in other implementations, some information (such as one item of the first to ninth information) can also be carried by cells carried in multiple signalings, and implemented through multiple sending steps (for the sender) or multiple receiving steps (for the receiver).

[0304] Fifteenth, the embodiments of the present application use the cellular system related to the 3rd Generation Partnership Project (3GPP) as an example to describe the method provided in the embodiments of the present application, but this should not constitute any limitation on the present application. Based on the same concept, the method provided in the present application can also be applied to other communication networks such as Zigbee, long-range radio (Lora), Bluetooth (BT), and wireless fidelity (Wi-Fi). For example, the method provided in the present application can be applied to a ZigBee network to replace the chirp spread spectrum (CSS) modulation in Section 14 of the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4, the Gaussian frequency shift keying (GFSK) in Section 16, the minimum shift keying (MSK) in Section 17, or the OFDM waveform generated by the present solution to replace the OFDM in Section 25 of IEEE 802.15.4, etc.; for another example, the method provided in the present application can be applied to Bluetooth communication to replace the GFSK in Section 3 of the Bluetooth Core Specification; for another example, the method provided in the present application can be applied to Lora communication to replace CSS; for another example, the method provided in the present application can be applied to a Wi-Fi system to replace the OFDM waveform defined in IEEE 802.11 by the OFDM waveform generated by the present solution.

[0305] It can be understood that by applying the solution provided in this application to different communication networks, the interference of multipath channels can be reduced through CP during broadband signal transmission.

[0306] In order to better understand the embodiments of the present application, the following first briefly explains the terms involved in the present application.

[0307] 1. Constant envelope waveform: This refers to a waveform whose envelope amplitude remains constant. This requires that not only the amplitude remains constant during modulation, but also the phase is continuous, without jumps. For a constant envelope waveform, the maximum and average power are always equal, resulting in a PAPR of 1. If PAPR is expressed logarithmically, taking the logarithm of 1 yields a PAPR of 0dB.

[0308] Phase modulation (PM) is a modulation method that transmits information by changing the phase of a carrier wave at the frequency of the modulating signal. By changing the phase of the carrier wave, the information to be transmitted is superimposed on the carrier signal for transmission. In other words, the amplitude of the carrier signal is not used to carry information.

[0309] Frequency modulation (FM) is a modulation method that uses the instantaneous frequency of a carrier wave to represent the information being transmitted. By varying the carrier wave's frequency, the information being transmitted is superimposed on the carrier wave signal. In other words, the amplitude of the carrier wave signal is not used to carry the information.

[0310] 4. Direct frequency modulation: Use the modulation signal to directly control the oscillation frequency of the oscillator so that it reflects the changing law of the modulation signal without distortion.

[0311] 5. Linear PA and Nonlinear PA: A linear PA amplifies a signal linearly, with the increase in output signal strength being in a 1:1 relationship with the increase in input signal strength. This results in less signal distortion, but it also results in higher power consumption.

[0312] A nonlinear PA amplifies a signal nonlinearly. The input-output function of the signal does not maintain a 1:1 constant amplitude relationship, but rather exhibits an unbounded amplification. This nonlinear approach distorts the signal amplitude, but it also reduces power consumption.

[0313] 6. Baseband signal: The original signal sent by the transmitter without modulation (such as spectrum shifting and transformation). Its characteristic is that the frequency is low and close to zero frequency.

[0314] The OFDM baseband signal in this application is a CP-based OFDM baseband signal. For ease of understanding and explanation, this article divides the OFDM baseband signal into two parts: the signal body and the CP. The CP is obtained by copying some symbols at the end of the signal body to the beginning of the signal body. In other words, the CP constitutes the header of the OFDM baseband signal.

[0315] 7. Bandpass Signal: Because baseband signals have low frequencies and high transmission losses, they must be modulated to a higher frequency. A bandpass signal is a baseband signal modulated by a carrier wave. By shifting the signal's frequency range to a higher frequency band, the signal can pass through the channel within a certain frequency range, allowing it to be transmitted within the channel.

[0316] 8. OFDM: A frequency division multiplexing technology that divides a channel into several orthogonal sub-channels, converting high-speed data signals into parallel, low-speed sub-data streams, modulating them for transmission on each sub-channel. Using OFDM allows for multi-carrier transmission, fully utilizing the channel bandwidth.

[0317] 7. Target frequency band: In the embodiment of the present application, for the convenience of distinction and explanation, the frequency band corresponding to the frequency domain resources actually used to transmit the first OFDM baseband signal is recorded as the target frequency band. The bandwidth of the target frequency band may be less than or equal to the bandwidth of the frequency band allocated by the network device. Since the first OFDM baseband signal is generated based on the second symbol sequence, and the second symbol sequence is generated based on the first symbol sequence, the first symbol sequence includes N symbols to be transmitted, and the first OFDM baseband signal can be obtained by up-conversion to obtain a bandpass signal, the frequency domain resources used to transmit the first OFDM baseband signal can also be called frequency domain resources for transmitting the second symbol sequence, or frequency domain resources for transmitting the first symbol sequence, or frequency domain resources for transmitting N symbols to be transmitted, or frequency domain resources for transmitting a bandpass signal.

[0318] The technical solutions provided in this application can be applied to various communication systems, such as: fifth generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, wireless local area networks (WLAN) systems, satellite communication systems, future communication systems, such as sixth generation (6G) mobile communication systems, or a fusion system of multiple systems. The technical solutions provided in this application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0319] A device in a communication system can send a signal to another device or receive a signal from another device. The signal may include information, signaling, or data, etc. The device may also be replaced by an entity, a network entity, a communication device, a communication module, a node, a communication node, etc. The present disclosure uses the device as an example for description. For example, the communication system may include at least one terminal device and at least one network device. The network device may send a downlink signal to the terminal device, and / or the terminal device may send an uplink signal to the network device. It is understandable that the terminal device in the present disclosure may be replaced by a first communication device, and the network device may be replaced by a second communication device, and both perform the corresponding communication methods in the present disclosure.

[0320] The radio access network (RAN) device in this application is a device with wireless transceiver functions. The radio access network device can provide wireless communication function services and can access the terminal device to the wireless network. The radio access network can also be called an access network device or a network device. The network device in the embodiment of the present application can refer to a radio access network (RAN) node (or device) used in a cellular network (or mobile network) to access the terminal device to the wireless network, and can also be a zigbee base station, a master Bluetooth (BT master), a master low energy (BLE) Bluetooth (BLE master), a Lora base station, or a Wi-Fi access point.

[0321] For example, a network device may be a base station. A base station may broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master station, auxiliary station, multi-standard radio (motor slide retainer, MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), radio unit (RU), positioning node, etc. A base station may be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. A base station may also refer to a communication module, modem, or chip configured within the aforementioned devices or apparatuses. A base station may also be a mobile switching center, a device that performs base station functions in D2D, V2X, or M2M communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. A base station may support networks with the same or different access technologies. Optionally, a RAN node may also be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle-to-everything (V2X) technology may be a roadside unit (RSU). The embodiments of this application do not limit the specific technology or device form factor employed by the network device. In some deployments, the network device referred to in the embodiments of this application may include a CU, a DU, or both a CU and a DU, or a control plane CU node (central unit-control plane (CU-CP)), a user plane CU node (central unit-user plane (CU-UP)), and a DU node. For example, the network device may include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0322] In some deployments, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes implementing portions of the base station's functionality. For example, a RAN node can be a CU, DU, CU-CP, CU-UP, or RU. The CU and DU can be separate or included in the same network element, such as the BBU. The RU can be included in a radio frequency device or radio unit, such as an RRU, AAU, or RRH.

[0323] The RAN node may support one or more types of fronthaul interfaces, and different fronthaul interfaces correspond to DUs and RUs with different functions. If the fronthaul interface between the DU and the RU is a common public radio interface (CPRI), the DU is configured to implement one or more baseband functions, and the RU is configured to implement one or more radio frequency functions. If the fronthaul interface between the DU and the RU is another interface, relative to the CPRI, it moves part of the downlink and / or uplink baseband functions, such as, for downlink, one or more of precoding, digital beamforming (BF), or inverse fast Fourier transform (IFFT) / CP addition, from the DU to the RU for implementation, and for uplink, one or more of digital beamforming (BF), or fast Fourier transform (FFT) / CP removal, from the DU to the RU for implementation. In one possible implementation, the interface may be an enhanced common public radio interface (eCPRI). In the eCPRI architecture, the division between DU and RU is different, corresponding to different types (category, Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, and F.

[0324] Taking eCPRI Cat A as an example, for downlink transmission, based on layer mapping, the DU is configured to implement layer mapping and one or more functions before it (i.e., one or more functions among coding, rate matching, scrambling, modulation, and layer mapping), while other functions after layer mapping (e.g., resource element (RE) mapping, digital BF, or IFFT / adding CP) are moved to the RU for implementation. For uplink transmission, based on de-RE mapping, the DU is configured to implement de-mapping and one or more functions before it (i.e., one or more functions among decoding, de-rate matching, de-scrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and de-RE mapping), while other functions after de-mapping (e.g., one or more functions among digital BF or FFT / de-CP) are moved to the RU for implementation. It can be understood that for the functional description of the DU and RU corresponding to various types of eCPRI, please refer to the eCPRI protocol and will not be repeated here.

[0325] In one possible design, the processing unit for implementing baseband functions in the BBU is called a baseband high layer (BBH) unit, and the processing unit for implementing baseband functions in the RRU / AAU / RRH is called a baseband low layer (BBL) unit.

[0326] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (open-RAN, O-RAN or ORAN) system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. The network device in this application may be a virtualized device, for example, implemented by general hardware and instantiated virtualization functions, or by dedicated hardware and instantiated virtualization functions. Among them, the general hardware may be a server, such as a cloud server.

[0327] In the embodiments of the present application, the device for implementing the functions of the network device can be a network device; it can also be a device that can support the network device to implement the functions, such as a chip system, a hardware circuit, a software module, or a hardware circuit and a software module. The device can be installed in the network device or used in conjunction with the network device. In the embodiments of the present application, only the device for implementing the functions of the network device is used as an example to illustrate, and does not constitute a limitation on the solutions of the embodiments of the present application.

[0328] The terminal device in this application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

[0329] The terminal device may be a device that provides voice / data, such as a handheld device or vehicle-mounted device with a wireless connection function. At present, some examples of terminals are: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, wearable devices, terminal devices in 5G networks or future evolved public land mobile communication networks (PLMNs). The terminal device in the PLMN network, the device in the ZigBee network, the device in the Lora network, the Bluetooth slave (BT slave), the BLE slave, the Wi-Fi station (STA), etc. The embodiment of the present application is not limited to this.

[0330] A terminal device can also be a terminal device in an IoT system, also known as an IoT node. IoT is a crucial component of future information technology development. Its primary technical feature is connecting objects to the network through communication technologies, thereby enabling intelligent networks that interconnect humans and machines, and objects and things. Connections can be achieved through both broadband and narrowband technologies. IoT technology, for example, uses narrowband (NB) technology to achieve massive connections, deep coverage, and power-saving terminals. IoT technologies include reflective communication, spread spectrum, and ultra-wideband (UWB), which are not detailed here.

[0331] In addition, terminal devices can also include sensors such as smart printers, train detectors, and gas stations. Their main functions include collecting data (part of the terminal devices), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0332] As an example and not a limitation, in the embodiment of the present application, the terminal device may also be a wearable device. Wearable devices may also be called wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0333] In the embodiments of the present application, the device for realizing the function of the terminal device can be a terminal device, or a device capable of supporting the terminal device to realize the function, such as a chip system, which can be installed in the terminal device or used in combination with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. In the embodiments of the present application, only the terminal device is used as an example for description, and the embodiments of the present application are not limited to the solutions of the embodiments of the present application.

[0334] The terminal device in this application can be a hardware device, a software function running on dedicated hardware, a software function running on general-purpose hardware, or a virtualized device, for example, implemented by general-purpose hardware and instantiated virtualization functions, or by dedicated hardware and instantiated virtualization functions. The general-purpose hardware can be a server, such as a cloud server.

[0335] Network devices and / or terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of the present application do not limit the scenarios in which the network devices and terminal devices are located. Figure 1 is a schematic diagram of the architecture of a communication system 10 used in the embodiments of the present application. Figure 1 shows a schematic diagram of a possible, non-limiting system architecture. As shown in Figure 1, the communication system 10 includes a radio access network (RAN) 100 and a core network 200. Optionally, the communication system 10 also includes the Internet 300. The RAN 100 may include at least one RAN node (such as 110a and 110b in Figure 1) and may also include at least one terminal device (such as 120a-120j in Figure 1). The terminal device can be connected to the radio access network device via wireless means. Terminal devices and radio access network devices can be connected to each other via wired or wireless means. The RAN node 110 is connected to the core network 200 via wireless or wired means. The core network device in the core network 200 and the RAN node 110 in the RAN 100 may be different physical devices, or may be the same physical device that integrates core network logical functions and radio access network logical functions.

[0336] FIG1 is only a schematic diagram. The communication system 10 may further include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in FIG1 .

[0337] The RAN 100 may be a cellular system related to the Third Generation Partnership Project (3GPP), such as a 4G or 5G mobile communication system, or a future-oriented evolutionary system (such as a 6G mobile communication system). The RAN 100 may also be an ORAN, a cloud radio access network (CRAN), a ZigBee network system, or a wireless fidelity (Wi-Fi) system. The RAN 100 may also be a communication system that integrates two or more of the above systems.

[0338] The RAN node can be a base station deployed in the air, such as a satellite base station 110a, or a base station deployed indoors, such as a micro base station or indoor station 110b. It should be understood that this application does not limit the specific technologies and device forms used by wireless access network devices. For ease of description, the following description uses a base station as an example of a wireless access network device.

[0339] The terminal device can be a terminal device deployed in the air, such as the helicopter or drone 120i in Figure 1; it can also be a terminal device deployed on the ground, such as the mobile phones 120a, 120e, 120f and 120j, vehicle 120b, computer 110b, printer 120h, etc. in Figure 1.

[0340] Optionally, the terminal device can also be used to act as a RAN node. For example, the UE can act as a scheduling entity that provides sidelink signals between terminal devices in vehicle-to-everything (V2X), device-to-device (D2D), or peer-to-peer (P2P) scenarios.

[0341] RAN nodes and terminal devices can be fixed or mobile. They can be deployed on land, indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of RAN nodes and terminal devices.

[0342] The roles of RAN nodes and terminal devices can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a RAN node. For terminal devices 120j accessing the RAN 100 via 120i, terminal device 120i is a RAN node. However, for RAN node 110a, 120i is a terminal device, meaning that communication between 110a and 120i occurs via a wireless air interface protocol. Of course, communication between 110a and 120i can also occur via an interface protocol between RAN nodes. In this case, 120i is also a RAN node relative to 110a. Therefore, RAN nodes and terminal devices can be collectively referred to as communication devices. 110a, 110b, and 120a-120j in Figure 1 can be referred to as communication devices with their respective functions, such as communication devices with RAN node functions or communication devices with terminal functions.

[0343] In the embodiments of the present application, the functions of the RAN node may also be performed by a module (such as a chip) in the RAN node, or by a control subsystem that includes the RAN node functions. The control subsystem that includes the RAN node functions here may be a control center in the application scenarios of the above-mentioned terminals, such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal device may also be performed by a module (such as a chip) in the terminal device, or by a device that includes the terminal device functions. This application does not limit this.

[0344] Furthermore, the present application can be applied to a variety of specific communication scenarios. For example, point-to-point transmission between RAN nodes and terminals or between terminals (such as (a) in Figure 2 is point-to-point transmission between RAN nodes and terminals), multi-hop transmission between RAN nodes and terminals (such as (b) in Figure 2, (c) in Figure 2), dual connectivity (DC) of multiple RAN nodes and terminals (such as (d) in Figure 2) or multi-connection scenarios. It should be noted that the above specific communication application scenarios are only examples and do not create limitations. In particular, from a business perspective, the embodiments of the present application are applicable to many business scenarios, such as data coding scenarios and uplink large-capacity scenarios in extended reality (XR) services. In addition, Figure 2 does not impose any restrictions on the network architecture applicable to the present application, and the present application does not limit uplink, downlink, access link, backhaul link, sidelink (SL) and other transmissions.

[0345] Currently, some low-cost, small-sized terminal devices, such as IoT nodes, often lack large-capacity batteries, resulting in short standby lifespans. One possible solution to improving the standby lifespan of these devices is to reduce transmit power. For example, these solutions can reduce supported frequency bands, lower operating rates, and reduce system bandwidth. However, the benefits of these solutions are relatively small. To further reduce costs and power consumption, proposals have been proposed to improve the transmitter architecture of terminal devices. For ease of understanding, the transmitter architecture is described below with reference to Figures 3 and 4.

[0346] Figure 3 is a schematic diagram of a transmitter structure currently used in terminal devices. As shown in Figure 3, the transmitter includes a baseband chip, an inphase / quadrature (I / Q) modulator, and a linear PA. After receiving the signal to be transmitted, the baseband chip can perform baseband processing, such as channel coding and modulation. The signals output by the baseband chip include an I-channel baseband signal and a Q-channel baseband signal. The I / Q modulator can be used to perform I / Q modulation on the baseband signals. Exemplarily, the I / Q modulator includes an I / Q generator, a mixer located on the I channel, and a mixer located on the Q channel. The I / Q generator generates the I and Q local oscillator signals, respectively. The I local oscillator signal can be input to the mixer on the I channel, and the Q local oscillator signal can be input to the mixer on the Q channel. Conversely, the I and Q baseband signals output from the baseband chip can be input to the mixers on the I / Q channels, respectively. The I-channel mixer can mix (or up-convert) the I-channel baseband signal based on the input I-channel local oscillator signal, and the Q-channel mixer can mix (or up-convert) the Q-channel local oscillator signal and the Q-channel baseband signal based on the input. In this way, the I-channel baseband signal and the Q-channel baseband signal are moved to the RF band, and superimposed to obtain a bandpass signal. The linear PA can linearly power amplify the bandpass signal and output the power-amplified bandpass signal. Optionally, the transmitter also includes a PLL, which can be used to output a frequency signal for frequency conversion processing to the I / Q generator and lock this frequency signal to the local oscillator frequency with high precision. In other words, the phase-locked loop can provide a local oscillator signal.

[0347] In the architecture shown in Figure 3, the I / Q modulator uses an I / Q generator to generate the I and Q local oscillator signals. Mixers are then used to up-convert the I and Q baseband signals, respectively. This results in a complex circuit structure and the need for mixers to shift the signal frequency band, which incurs additional power consumption. Furthermore, linear power amplification also results in significant power consumption. Therefore, the transmitter architecture shown in Figure 3 results in high transmit power consumption.

[0348] Therefore, the transmitter structure shown in FIG3 may be improved to reduce the transmission power consumption from at least one of the two dimensions of up-conversion and power amplification.

[0349] Figure 4 is a schematic diagram of a transmitter structure applicable to the communication method provided in an embodiment of the present application. Figure 4 shows three different transmitter structures (a), (b), and (c).

[0350] The transmitter shown in Figure 4 (a) includes a baseband chip, an upconversion module, and a nonlinear PA. After receiving the signal to be transmitted, the baseband chip performs baseband processing, such as channel coding and modulation, and then outputs a baseband signal. The upconversion module directly modulates the carrier frequency based on the baseband signal to shift the baseband signal to the radio frequency band, generating a bandpass signal. The nonlinear PA performs nonlinear power amplification on the bandpass signal, thereby outputting the amplified bandpass signal. By way of example and not limitation, the upconversion module may include a PLL (as shown in the figure), a VCO, or a DCO. As can be seen, Figure 4 (a) directly modulates the carrier frequency, avoiding the need for signal band shifting via a mixer in I / Q modulation, thereby saving power. Furthermore, the nonlinear PA also offers significantly lower power consumption than a linear PA. Therefore, transmit power consumption is reduced through both upconversion and power amplification.

[0351] The transmitter shown in Figure 4 (b) includes a baseband chip, an I / Q modulator, and a nonlinear PA. After receiving the signal to be transmitted, the baseband chip performs baseband processing, such as channel coding and modulation, and outputs an I-channel baseband signal and a Q-channel baseband signal. The I-channel baseband signal and the Q-channel baseband signal are input to the mixer on the I channel and the mixer on the Q channel, respectively. The I / Q generator generates an I-channel local oscillator signal and a Q-channel local oscillator signal, which are input to the mixer on the I channel and the mixer on the Q channel, respectively. The I / Q mixers perform mixing operations based on the input I-channel baseband signal, the I-channel local oscillator signal, and the Q-channel baseband signal, respectively. In this way, the I / Q baseband signals are shifted to the RF band and superimposed to produce a bandpass signal. The nonlinear PA performs nonlinear power amplification on the bandpass signal, outputting the amplified bandpass signal. It can be seen that (b) in FIG4 can reduce the transmission power consumption from the dimension of power amplification by performing nonlinear power amplification on the bandpass signal.

[0352] The transmitter shown in Figure 4 (c) includes a baseband chip, an upconversion module (such as the PLL shown in the figure), and a linear PA. After receiving the signal to be transmitted, the baseband chip performs baseband processing on the signal, such as channel coding and modulation, and then outputs a baseband signal. The upconversion module directly modulates the carrier frequency based on the baseband signal to shift the baseband signal to the RF band, generating a passband signal. The linear PA performs nonlinear power amplification on the passband signal and then outputs the amplified passband signal. As can be seen, Figure 4 (c) avoids the need for frequency shifting the signal using a mixer in I / Q modulation by directly modulating the carrier frequency, thereby reducing transmit power consumption through upconversion.

[0353] Those skilled in the art will recognize that both direct frequency modulation and nonlinear PAs have strict waveform requirements: namely, a constant envelope waveform with a PAPR of 0 dB is required for data transmission. However, current cellular networks utilize OFDM technology. To prevent interference between OFDM symbols, a guard period (CP) is typically inserted between OFDM symbols. The CP is typically constructed by copying the signal at the end of an OFDM symbol to the beginning. Even if continuous phase modulation techniques are used to ensure phase continuity of the signal itself, phase continuity between the CP and the subsequent signal cannot be guaranteed, and thus, a constant waveform envelope cannot be maintained.

[0354] In view of this, the present application provides a method for extending a modulated symbol sequence by adding several additional symbols to ensure that the phase difference between the beginning and end of the modulated symbol sequence is an integer multiple of 2π, that is, the beginning and end phases are continuous. The baseband signal generated by this modulated symbol sequence also satisfies the phase continuity between the beginning and end, thus facilitating the acquisition of a phase-continuous waveform.

[0355] On this basis, if modulation methods that can ensure phase continuity, such as CPM or LFM, are adopted, a phase-continuous modulation symbol sequence can be obtained. By combining these modulation techniques that can ensure phase continuity with the method provided in this application, the resulting modulation symbol sequence can meet the following requirements: phase continuity, and phase continuity from beginning to end. The resulting baseband signal can also meet phase continuity. CPM and LFM are modulation methods that modulate the information to be transmitted on the phase or frequency, and the amplitude does not change during the modulation process. This can produce a constant envelope waveform with continuous phase and constant amplitude.

[0356] In addition, the present application further considers the situation of sending data on multiple consecutive OFDM symbols. By extending the symbol sequence to be transmitted, the modulation symbol sequence obtained after the extended symbols are modulated satisfies double head-to-tail phase continuity. That is, if the modulation symbol sequence is divided into two parts, and the length of the second half is not less than the length of the CP, that is, K1 modulation symbols, that is, the number of modulation symbols included in the second half is not less than K1, the two parts respectively satisfy the phase continuity from head to tail, where K1 is a positive integer. In this way, the head and tail phases of the modulation symbol sequence obtained after each OFDM symbol is extended and modulated are also continuous with the initial phase of the OFDM symbol, that is, the phase difference satisfies an integer multiple of 2π. In this way, the initial phase of the signal sent on each OFDM symbol can be controlled by controlling the initial phase, so that the signal on each OFDM symbol is not only phase-continuous on the OFDM symbol itself, but also phase-continuous with the signals on the previous and next OFDM symbols. Thus, a constant envelope waveform can be obtained on multiple consecutive OFDM symbols. In this way, the constant envelope waveform can be applied to the transmitter structure shown in Figure 4 above, or in other words, the communication device can use a processing method with lower transmission power consumption to send signals, thereby saving power consumption and improving standby life.

[0357] In order to better understand the embodiments of the present application, the following briefly describes the processing process after the signal reaches the physical layer with reference to FIG5 .

[0358] The signal processing process shown in FIG5 can be performed by one of the terminal devices or the network devices as a sending end, or can be performed by one of the terminal devices or the network devices as a receiving end, which is not limited in this application.

[0359] As shown in Figure 5, the transmitting end's physical layer divides the information sequence from the upper layer (e.g., the medium access control (MAC) layer) into multiple transport blocks (TBs) and adds a cyclic redundancy check (CRC) to each transport block. If the size of the transport block after adding the check exceeds the maximum code block length, the transport block needs to be divided into several code blocks (CBs).

[0360] The transmitter can perform channel coding on each code block, such as polar code coding, to obtain a corresponding coded code block, perform rate matching on the coded code block, and concatenate the rate-matched code blocks to form a codeword (CW).

[0361] The transmitter scrambles the codewords to generate scrambled bits. These scrambled bits are modulated to produce modulation symbols. After RE mapping, the modulation symbols are mapped to multiple REs, resulting in the value carried by each RE. Based on the values ​​carried by these REs, the transmitter generates an OFDM baseband signal. The OFDM baseband signal is upconverted to a passband signal, which is then amplified and transmitted through the transmit antenna.

[0362] The receiving end receives the signal through the receiving antenna. After receiving the passband signal from the transmitting end, the receiving end can downconvert the passband signal to obtain the first OFDM baseband signal. The receiving end's physical layer then performs RE demapping, demodulation, descrambling, rate matching, and channel decoding on the signal to obtain the information sequence.

[0363] Optionally, after completing RE demapping and before performing demodulation, the receiving end may also perform channel equalization. Channel equalization uses an equalization algorithm to remove the effects of the channel based on channel estimation, thereby ensuring correct signal demodulation. It will be understood that the information sequence received by the receiving end corresponds to the information sequence to be sent by the transmitting end.

[0364] Optionally, after completing modulation and before performing RE mapping, the transmitter can also perform layer mapping and precoding. For example, the transmitter can map the modulation symbols to multiple layers, and then precode the modulation symbols after layer mapping to obtain a precoded signal. The precoded signal is mapped to multiple REs through RE mapping. Correspondingly, before completing RE demapping and performing channel equalization, the receiver can also perform layer demapping and deprecoding to perform channel equalization.

[0365] Since the specific implementation of each step in FIG5 can be implemented by existing technologies, please refer to the 3rd Generation Partnership Project (3 rd The relevant sections in the 3GPP technical specification (TS) 38.211 are not described in detail here.

[0366] Figure 5 is only an example. In other communication technology-related standards, the signal processing process may include some of the operations. For example, in Zigbee technology, the physical layer operations of the transmitter may include encoding, modulation, transmission, etc., and the physical layer operations of the receiver may include reception, demodulation, decoding, etc.

[0367] The operations of the transmitter and the physical layer in different communication technologies may refer to their respective existing technologies, such as relevant standards, and examples will not be given one by one.

[0368] The communication method provided by the present application will be described in detail below with reference to the accompanying drawings. In the following embodiments, two different implementation methods for implementing the communication method provided by the present application are provided, taking the processes shown in Figures 6 and 15 as examples. In the process shown in Figure 6, the first communication device (such as a terminal device) can, after acquiring the first symbol sequence to be transmitted, expand it to obtain a third symbol sequence, and then perform RE mapping after modulating the third symbol sequence, and generate a first OFDM baseband signal based on the second symbol sequence obtained by RE mapping. This process may be similar to the generation process of the OFDM baseband signal defined in the current standard. In the process shown in Figure 15, the first communication device can pre-generate a first CP sequence corresponding to the CP of the first OFDM baseband signal before generating the first OFDM baseband signal. By comparison, it can be seen that in the process shown in Figure 6, the first communication device generates the CP of the first OFDM baseband signal during the generation of the first OFDM baseband signal without pre-generating the first CP sequence.

[0369] Furthermore, Figures 6 and 15 illustrate the communication methods provided herein, using a terminal device sending N symbols to be transmitted to a network device as an example of data transmission. The terminal device is an example of a first communication device, and the network device is an example of a second communication device. That is, the terminal device can be replaced by the first communication device, and the network device can be replaced by the second communication device. It should be understood that the methods illustrated in Figures 6 and 15 are not only applicable to data transmission from a terminal device to a network device, but can also be used for data transmission from a network device to a terminal device, that is, the first communication device can be a network device and the second communication device can be a terminal device. They can also be used for communication between terminal devices, that is, both the first communication device and the second communication device can be terminal devices. This application is not limited in this regard. Furthermore, the terminal device can also be replaced by a component used in the terminal device, such as a chip, a chip system, a processor, or a logic module or software capable of implementing all or part of the functions of the terminal device. The network device can also be replaced by a component used in the network device, such as a chip, a chip system, a processor, or a logic module or software capable of implementing all or part of the functions of the network device.

[0370] The two implementations are described below in conjunction with the accompanying drawings.

[0371] FIG6 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0372] The method 600 shown in Figure 6 may include steps 601 to 610. Steps 601 to 606 are processes executed by the terminal device, and steps 606 to 610 are processes executed by the network device. Exemplarily, steps 601 to 603 can be executed by the baseband chip of the terminal device, and steps 604 to 605 can be executed by the radio frequency chip of the terminal device, wherein step 604 can be executed by the up-conversion module in the radio frequency chip, step 605 can be executed by the power amplifier in the radio frequency chip, and the sending operation in step 606 can be executed by the antenna (such as a transmitting antenna) of the terminal device. The receiving operation in step 606 can be executed by the antenna (such as a receiving antenna) of the network device, step 607 can be executed by the radio frequency chip of the network device, and steps 608 to 610 can be executed by the baseband chip of the network device.

[0373] The various steps in method 600 are described in detail below.

[0374] In step 601, a terminal device obtains a first symbol sequence, where the first symbol sequence includes N symbols to be transmitted.

[0375] For example, the terminal device (specifically, a baseband chip in the terminal device) can perform baseband processing on the information to be transmitted from the higher layer, such as channel coding, rate matching, modulation, etc., to obtain N symbols to be transmitted. The modulation can include, but is not limited to, one-dimensional modulation schemes such as PAM, π / 2-BPSK, BPSK, and QPSK.

[0376] One-dimensional modulation refers to modulation performed in one of the three dimensions: amplitude, phase, or frequency. Through a predefined mapping, the transmitted bit sequence is modulated to output a value in one of the dimensions in the complex plane, in other words, a real number or a purely imaginary number.

[0377] In step 602, the terminal device obtains a second symbol sequence based on the first symbol sequence.

[0378] In this embodiment, the terminal device can obtain the second symbol sequence through modulation.

[0379] As previously mentioned, if modulation is performed directly based on the first symbol sequence, the resulting OFDM baseband signal may experience phase jumps between the CP and the signal itself, resulting in an unstable envelope. Therefore, the terminal device can add several additional extended symbols to the first symbol sequence. By designing these extended symbols, the phase of the modulation symbol sequence is self-looped at the beginning and end, ensuring phase continuity between the CP and the signal itself in the generated OFDM baseband signal.

[0380] Optionally, step 602 includes:

[0381] Step 6021: The terminal device determines a third symbol sequence based on the first symbol sequence;

[0382] Step 6022: The terminal device performs modulation based on the third symbol sequence to obtain a fourth symbol sequence.

[0383] In step 6023, the terminal device maps the modulation symbols in the fourth symbol sequence to RE to obtain a second symbol sequence.

[0384] The third symbol sequence includes the N symbols to be transmitted and the M extended symbols. In step 6021, the third symbol sequence can be calculated based on the modulation scheme and the first symbol sequence. Specifically, by inserting the M extended symbols before, within, or after the N symbols to be transmitted, the modulated symbol sequence (also referred to as the fourth symbol sequence described below) obtained after the insertion of the M extended symbols is modulated and exhibits a self-looping characteristic of the first and last phases.

[0385] It should be noted that steps 6021 and 6022 are not necessarily performed separately and may be performed simultaneously. For ease of understanding, the description herein is divided into two steps. For example, the terminal device may perform modulation while determining the third symbol sequence, rather than performing modulation after determining the third symbol sequence.

[0386] If modulation is performed directly based on the first symbol sequence, the phases of the modulated symbol sequence obtained may be discontinuous at the beginning and end, which in turn may cause discontinuity between the CP of the OFDM baseband signal generated by the modulated symbol sequence and the main signal. Therefore, the terminal device can add a number (e.g., M) of extended symbols to the first symbol sequence, and achieve self-circulation of the phases of the beginning and end of the fourth symbol sequence by designing the extended symbols, so that the phases of the CP of the first OFDM baseband signal generated based on the fourth symbol sequence are continuous with the main signal, that is, a phase-continuous waveform is obtained.

[0387] It can be understood that when M is zero, the third symbol sequence is the same as the first symbol sequence; when M is greater than zero, the third symbol sequence is different from the first symbol sequence. The third symbol sequence is a sequence obtained by adding one or more extended symbols to the first symbol sequence while maintaining the order of its N symbols to be transmitted unchanged.

[0388] By way of example and not limitation, the modulation in this application is continuous phase modulation. Exemplarily, the modulation includes CPM or LFM. Since CPM is phase modulation and LFM is frequency modulation, the modulation described herein may also be referred to as phase or frequency modulation.

[0389] The following will illustrate step 6021 by combining CPM and linear frequency modulation respectively.

[0390] CPM:

[0391] A nonlinear modulation scheme that carries information through the carrier phase, and its transmitted signal has the characteristics of constant envelope and continuous phase change. Assume that the first symbol sequence a is: {a1, a2, a3, ..., a N}, including N symbols to be transmitted. The bandpass waveform s(t,a) obtained by performing CPM on the first symbol sequence a satisfies:

[0392] in, represents the phase of the first symbol sequence a at time t. By connecting the phases at different times, we can get the baseband waveform. satisfy: E is the energy symbol; T is the duration of each symbol; for the first symbol sequence a, the value of t satisfies: 0≤t≤NT; f c is the carrier frequency; is the initial phase of the carrier; h is the modulation index, or the modulation index of the CPM signal; a i is the i-th symbol to be transmitted in the first symbol sequence a; g(t) is the frequency pulse shaping function that satisfies: q(t) represents the phase pulse shaping function; is the initial phase of CPM.

[0393] If M additional extended symbols are added to the symbol sequence a, the symbol sequence is obtained Then the symbol sequence As long as the phase difference between the starting position and the ending position is an integer multiple of 2π, the self-circulating characteristic of the first and last phases can be satisfied.

[0394] In the embodiment of the present application, it is assumed that the first symbol sequence is the aforementioned symbol a, and the third symbol sequence is the symbol sequence Then for the third symbol sequence Perform CPM, the value of t satisfies: 0≤t≤(N+M)×T, and the phase of the starting position of the fourth symbol sequence can be expressed as Fourth symbol sequence The phase of the end position can be expressed as The phase difference between the starting position and the ending position of the fourth symbol sequence is an integer multiple of 2π, which can be expressed as: k1 is an integer.

[0395] To better understand the relationship between the M extended symbols and the head-to-tail phase self-loop, the following example is illustrated with reference to FIG7 . FIG7 is an example of a third symbol sequence provided in an embodiment of the present application. The figure illustrates the phase variation of the third symbol sequence. For ease of distinction, the N symbols to be transmitted and their corresponding phase variations are represented by solid lines, while the M extended symbols and their corresponding phase variations are represented by dashed lines.

[0396] Assuming N = 3, the N symbols to be transmitted in the first symbol sequence can be obtained through PAM, and are: +1, +1, -1. Assume that the mapping relationship between the symbols obtained by PAM and the phase difference of CPM is: a symbol with a value of +1 corresponds to a phase difference of +90°, a symbol with a value of -1 corresponds to a phase difference of -90°, and the initial phase of CPM is 0°. Based on this mapping relationship, the phase of the symbols in the first symbol sequence undergoing CPM changes as follows: 0° → 90° → 180° → 90°. It can be seen that if no additional extended symbols are added to the first symbol sequence, the phase difference between the +90° at the end position and the 0° at the starting position of the first symbol sequence is 90°, indicating a phase jump. If the difference between the first and last phases is desired to be an integer multiple of 2π, a single extended symbol, -1, can be added to the end of the N symbols to be transmitted, resulting in the following third symbol sequence: +1, +1, -1, -1. By adding the extension symbol -1, the phase at the end position is adjusted from 90° to 0° by a phase difference of -90°, and the phase difference from the starting position is an integer multiple of 2π. The (N+M) symbols in the third symbol sequence are: +1, +1, -1, -1.

[0397] Of course, adding one extended symbol at the end of N symbols to be transmitted is only one possible way, not the only one. For example, more extended symbols can be added at the end of N symbols to be transmitted, or one or more extended symbols can be added at the beginning or other positions of N symbols to be transmitted, and so on.

[0398] It should be understood that the above formula for the baseband waveform of CPM is only an example. Those skilled in the art can make equivalent replacements or simple transformations to derive other formulas, and this application includes but is not limited to this.

[0399] LFM:

[0400] A spread spectrum modulation technique that does not require a pseudo-random code sequence. An LFM signal is one whose instantaneous frequency varies linearly with time. The bandpass signal s(t,a) obtained by LFMing the symbol sequence a satisfies:

[0401] in, represents the phase of the symbol sequence a at time t. By connecting the phases at different times, the baseband waveform can be obtained. For the symbol sequence a, the value of t satisfies: 0≤t≤NT; A is the amplitude; f c is the carrier frequency; F is the frequency modulation slope of LFM, 1 / T is the information bandwidth, FT>>1, is the maximum peak value of the matched filter output; is the initial phase of the carrier.

[0402] Similar to CPM, if the phase difference between the baseband waveform at any two adjacent times is an integer multiple of 2π, the baseband waveform satisfies phase continuity, and the passband waveform is also phase continuous. Therefore, if M additional extended symbols are added to the symbol sequence a, the symbol sequence is obtained. Then the symbol sequence As long as the phase difference between the starting position and the ending position is an integer multiple of 2π, the self-circulating characteristic of the first and last phases can be satisfied.

[0403] In the embodiment of the present application, it is assumed that the first symbol sequence is the aforementioned symbol a, and the third symbol sequence is the symbol sequence Then for the third symbol sequence Perform LFM, the value of t satisfies: 0≤t≤(N+M)×T, and the phase of the starting position of the fourth symbol sequence can be expressed as Fourth symbol sequence The phase of the end position can be expressed as, The phase difference between the start position and the end position of the fourth symbol sequence is an integer multiple of 2π, which can be expressed as: k1 is an integer.

[0404] For the description of the M extended symbols and the self-loop of the first and last phases, please refer to the example in conjunction with FIG7 . LFM is similar to it and will not be described in detail.

[0405] It should be understood that the above formula for the baseband waveform of LFM is only an example, and those skilled in the art can make equivalent replacements or simple transformations thereto to derive other formulas, which are included in but not limited to the present application.

[0406] In step 6022, the terminal device may perform modulation based on the third symbol sequence. The process of the terminal device performing modulation based on the third symbol sequence may be implemented in a variety of possible implementations, and different implementations will be described in detail below with reference to the accompanying drawings.

[0407] A possible implementation of step 6022 is shown in FIG8 , where the third symbol sequence is modulated to obtain a fourth symbol sequence.

[0408] That is, the third symbol sequence is used as a modulation input, the third symbol sequence is modulated, and the modulation output is the fourth symbol sequence.

[0409] Since the modulation method provided in this application is intended to ensure phase-continuous modulation, the (N+M) modulation symbols obtained through modulation are continuous and must be sampled to be stored in a digital system. Therefore, after modulation, each modulation symbol obtained through modulation can also be sampled. Sampling can be considered an independent operation, as shown in the figure, where sampling is performed after modulation. Alternatively, sampling can be considered part of modulation, in which case the sampling in the figure can be combined with modulation. This application does not limit this.

[0410] Assuming that the sampling rate is S, where S is a positive integer, S samples are taken for each modulation symbol, and each modulation symbol can be recorded by the S samples obtained by sampling. Since the third symbol sequence includes (N+M) symbols, (N+M) modulation symbols can be obtained after modulation, so (N+M)×S time domain samples can be obtained by sampling. In an embodiment of the present application, the fourth symbol sequence may refer to the continuous (N+M) modulation symbols obtained by modulation, or may refer to the (N+M)×S samples obtained by sampling. The (N+M) modulation symbols and the (N+M)×S time domain samples can be regarded as two different forms of the fourth symbol sequence.

[0411] Another possible implementation of step 6022 is shown in Figure 9, which modulates the N to-be-transmitted symbols and M extended symbols in the third symbol sequence respectively to obtain N modulation symbols and M modulation symbols; according to the positions of the M extended symbols in the third symbol sequence, the M modulation symbols are inserted into the N modulation symbols, and phase compensation is performed on at least part of the N modulation symbols so that the phases of the (M+N) modulation symbols after the insertion of the M modulation symbols are continuous (which may correspond to the splicing operation in Figure 9), thereby obtaining a second symbol sequence.

[0412] Since the present application does not limit the position of the M modulation symbols in the third symbol sequence, the M modulation symbols can be continuous and located before or after the N symbols to be transmitted, or the M modulation symbols can be distributed continuously or discretely among the N symbols to be transmitted. Due to the phase accumulation characteristic of CPM itself, when the M modulation symbols are inserted into the N symbols to be transmitted, it is necessary to consider the phase continuity between the inserted M modulation symbols and the N modulation symbols, and therefore phase compensation is required.

[0413] For ease of understanding, the following example illustrates the phase compensation process.

[0414] In an example, assuming N=3, M=1, the position of the M extended symbols in the third symbol sequence is located before the N symbols to be transmitted, for example, denoted as: aex1 , a1, a2, a3, a1 to a3 are symbols to be transmitted, a ex1 For the expansion symbol, with the expansion symbol a ex1 As the boundary, the third symbol sequence can be divided into two parts, which are respectively recorded as: a1 (including a ex1 ) and a2 (including a1, a2, and a3). Taking CPM as an example, if CPM is performed on a1 and a2 respectively to obtain M modulation symbols corresponding to a1 and N modulation symbols corresponding to a2, the phases of the N modulation symbols can be phase-compensated according to the difference between the phases of the end positions of the M modulation symbols and the phases of the starting positions of the N modulation symbols, so that the phase difference between the N modulation symbols and the M modulation symbols is an integer multiple of 2π.

[0415] For example, in this example, assuming the initial phase of CPM is The phase of the end position of M modulation symbols is: The phase of the starting position of N modulation symbols is: The phase difference between the end position of M modulation symbols and the start position of N modulation symbols is: Therefore, the phases of the N modulation symbols can be compensated according to the phase difference. The phases of the starting positions of the N modulation symbols obtained after compensation are: That is, The phase of the end position of the N modulation symbols obtained after compensation is: k2 is an integer.

[0416] In another example, assuming that N=3, M=2, M extended symbols are discretely distributed in the third symbol sequence, one extended symbol is located after the first to-be-transmitted symbol among the N to-be-transmitted symbols, and the other extended symbol is located after the N to-be-transmitted symbols, for example, denoted as: a1, a ex1 , a2, a3, a ex2 , a1 to a3 are symbols to be transmitted, a ex1 and a ex2 For the expansion symbol, respectively with the expansion symbol a ex1 and a ex2 As the boundary, the third symbol sequence can be divided into three parts, which are respectively denoted as a1 (including a1, a ex1 ), a2 (including a2, a3) and a3 (including a ex2). Taking CPM as an example, if CPM is performed on a1, a2 and a3 respectively, one modulation symbol corresponding to a1 is obtained (for the convenience of distinction and explanation, it is recorded as symbol block 1), two modulation symbols corresponding to a2 are obtained (for the convenience of distinction and explanation, it is recorded as symbol block 2) and one modulation symbol corresponding to a3 is obtained (for the convenience of distinction and explanation, it is recorded as symbol block 3). Except for the part at the front, the phase of the modulation symbol of each of the other two parts needs to be phase-compensated based on the difference between the phase of the end position of the previous part and the phase of the starting position of the latter part. For example, the phase of symbol block 2 needs to be compensated based on the difference between the phase of the end position of symbol block 1 and the phase of the starting position of symbol block 2, and the phase of symbol block 3 needs to be compensated based on the difference between the phase of the end position of symbol block 2 after phase compensation and the phase of the starting position of symbol block 3.

[0417] For example, in this example, assuming the initial phase of CPM is The phase of the end position of symbol block 1 is The phase of the starting position of symbol block 2 is: The phase difference between the starting position of symbol block 2 and the ending position of symbol block 1 is: Therefore, the phase of symbol block 2 can be compensated according to the phase difference. The phase of the starting position of symbol block 2 obtained after compensation is: The phase of the end position of symbol block 2 is: k3 is an integer. After the phase compensation is performed on symbol block 2, the phase of symbol block 3 can be compensated according to the difference between the phase of the end position of symbol block 2 after compensation and the phase of the starting position of symbol block 3. The phase of the starting position of symbol block 3 is The phase difference between the end position of symbol block 3 and the start position of symbol block 2 after compensation is: k4 is an integer. Therefore, the phase of symbol block 3 can be compensated according to the phase difference, and the phase of the starting position of symbol block 3 obtained after compensation is: The phase of the end position of symbol block 3 is:

[0418] The above examples illustrate the phase compensation process using different values ​​of M and different positions in the third symbol sequence. Those skilled in the art can, based on the same concept, perform phase compensation for any value of M and at any position in the third symbol sequence. For the sake of brevity, further examples are not provided here. Furthermore, the above example provides only one possible method for phase compensation, and this application does not exclude the possibility of performing phase compensation using other methods to obtain a phase-continuous fourth symbol sequence.

[0419] Similar to Figures 8 and 9 , after modulating the N symbols to be transmitted and the M extended symbols, each modulated symbol obtained by modulation may be sampled. Sampling may be considered an independent operation, as shown in the figure, where sampling is performed after modulation. Alternatively, sampling may be considered part of modulation, in which case the sampling in the figure may be combined with modulation, which is not limited in this application.

[0420] Assuming a sampling rate of S, sampling the N modulation symbols and the M modulation symbols yields N×S samples and M×S samples, respectively. The aforementioned process of inserting M modulation symbols into N modulation symbols is similar to the process of inserting M×S samples into N×S samples, and is not described in detail here.

[0421] The above text, in combination with FIG8 and FIG9 , shows two possible implementations of step 6022 . These implementations are merely examples and should not constitute any limitation to this application. This application does not limit the specific implementation of step 6022 .

[0422] In the several implementations exemplified above, the fourth symbol sequence can be recorded by sampling points. The sampling rate S can be predefined, configured by a network device, or determined by a terminal device, which is not limited in this application.

[0423] If the sampling rate S is configured by the network device, optionally, the method further includes: the terminal device receiving second information from the network device, or the network device sending second information to the terminal device, where the second information is used to indicate the sampling rate S. The network device can indicate the sampling rate S to the terminal device through the second information, thereby facilitating the network device to determine the number of subcarriers used to transmit the second symbol sequence, and further correctly demodulate the received signal.

[0424] If the sampling rate S is determined by the terminal device, optionally, the method further includes: the terminal device sending second information to the network device, or the network device receiving second information from the terminal device, where the second information is used to indicate the sampling rate S. The terminal device may also determine the sampling rate S on its own, for example, based on factors such as transmission rate and demodulation performance, and then indicate the sampling rate S to the network device through the second information, so that the network device can correctly demodulate the received signal.

[0425] After obtaining the fourth symbol sequence through modulation, the terminal device may execute step 6023 to map each modulation symbol in the fourth symbol sequence to an RE, thereby obtaining a value carried by each RE. For ease of distinction and explanation herein, the symbol sequence after RE mapping is referred to as a second symbol sequence. The symbols in the second symbol sequence are obtained by mapping the (N+M) modulation symbols in the fourth symbol sequence to the REs.

[0426] The fourth symbol sequence can be understood as a CP-based single carrier (SC) symbol. After converting a CP-SC symbol to the frequency domain, it is mapped to multiple subcarriers to obtain a DFT-s-OFDM waveform.

[0427] It should be understood that in baseband chips, RE mapping primarily refers to frequency domain mapping in the baseband. Therefore, frequency domain mapping can be considered as determining the relative positions of each subcarrier when mapping the signal to the frequency domain resources. In step 604 below, the terminal device will move the signal from the baseband to the target frequency band, which will not be described in detail here.

[0428] It should be noted that RE mapping is a step corresponding to the 3GPP standard. For the specific implementation process, please refer to the relevant sections on RE mapping in TS 38.211, which will not be described in detail here. In the present application, the (N+M) modulation symbols in the fourth symbol sequence are mapped to RE, including but not limited to RE mapping. Since the fourth symbol sequence is a symbol sequence in the time domain, RE mapping is performed in the frequency domain. Therefore, the (N+M) modulation symbols in the fourth symbol sequence can be converted to the frequency domain for RE mapping. In other words, mapping the (N+M) modulation symbols in the fourth symbol sequence to RE, in addition to RE mapping, also includes: converting the (N+M) modulation symbols in the fourth symbol sequence to the frequency domain and other operations. For details, please refer to the detailed description of this step in combination with Method 1 and Method 2 below.

[0429] Method 1: convert the fourth symbol sequence into the frequency domain and then perform frequency domain interleaving mapping to obtain the second symbol sequence.

[0430] As mentioned above, the fourth symbol sequence includes (N+M)×S samples. Since the fourth symbol sequence is a time domain signal, the (N+M)×S samples are time domain samples. By converting the (N+M)×S time domain samples to the frequency domain, (N+M)×S frequency domain samples can be obtained. RE mapping is performed on the (N+M)×S frequency domain samples so that each frequency domain sample is mapped to a subcarrier. Each of the above (N+M)×S subcarriers can be used to transmit a frequency domain sample. By mapping the (N+M)×S frequency domain samples to (N+M)×S subcarriers, the value carried by each RE can be determined, and the above second symbol sequence is obtained. One possible form of the second symbol sequence is (N+M)×S frequency domain samples carried on (N+M)×S subcarriers. Starting from the first of the (N+M)×S frequency domain samples, each S frequency domain sample corresponds to one of the (N+M) modulation symbols of the fourth symbol sequence. From a frequency domain perspective, the (N+M)×S frequency domain samples can also be called (N+M)×S modulation symbols.

[0431] Among them, the method used to convert the signal from the time domain to the frequency domain may include but is not limited to FFT, discrete Fourier transform (DFT), etc., and the method used to convert the signal from the frequency domain to the time domain may include but is not limited to IFFT, IDFT, etc., which is not limited in this application.

[0432] Optionally, the (N+M)×S subcarriers are continuous. The (N+M)×S subcarriers are continuous, which may specifically mean that the numbers of the (N+M)×S subcarriers are continuous. The above (N+M)×S frequency domain samples are mapped to continuous (N+M)×S subcarriers.

[0433] Optionally, the (N+M)×S subcarriers are in a comb-shaped pattern, and the subcarrier offsets between every two adjacent comb teeth are equal. In other words, the (N+M)×S subcarriers are discontinuous, or in other words, the subcarrier numbers of the (N+M)×S subcarriers are discontinuous. The subcarrier offsets between every two adjacent comb teeth are equal, that is, the number of subcarriers offset between every two subcarriers of the (N+M)×S subcarriers is equal. In other words, the (N+M)×S subcarriers are equally spaced.

[0434] Assume that the subcarrier offset is Z p (Z p is a positive integer), that is, there is Z between every two adjacent comb teeth. p subcarriers are not used to transmit the above N symbols to be transmitted. p The subcarriers can be empty or used to transmit other signals, which is not limited in this application. p =1, indicating that the (N+M)×S subcarriers are continuous; when Z p >1, indicating that the (N+M)×S subcarriers are discontinuous.

[0435] Figure 10 shows a schematic diagram of (N+M)×S subcarriers. Figure 10 shows a plurality of consecutive subcarriers, wherein the black boxes represent subcarriers used to carry the first OFDM baseband signal, which is an example of the above-mentioned (N+M)×S subcarriers and can be referred to as data subcarriers. The white boxes represent subcarriers not used to carry data and can be referred to as null subcarriers. The black boxes are evenly spaced among the plurality of subcarriers, forming a comb-shaped pattern, and the subcarrier offset Z between each two adjacent comb teeth is 1 / 4. p =2.

[0436] When the frequency domain resources allocated by the network device to the terminal device contain more than (N+M)×S subcarriers, based on the above design, (N+M)×S frequency domain samples can be mapped on the frequency domain resources at equal intervals. This frequency domain mapping method can be called frequency domain interleaving mapping. Simply put, frequency domain interleaving mapping includes frequency domain interleaving and RE mapping. Frequency domain interleaving and RE mapping can be performed simultaneously, or frequency domain interleaving can be performed first and then RE mapping, or RE mapping can be performed first and then frequency domain interleaving. This application does not limit this.

[0437] Through frequency domain interleaving mapping, there are one or more empty subcarriers between every two subcarriers carrying the above frequency domain samples, and the number of empty subcarriers between every two adjacent data subcarriers is equal. Among them, zeros can be inserted on the empty subcarriers between every two adjacent data subcarriers. Therefore, the number of frequency domain samples (N+M)×S, and the subcarrier offset Z p , the number of time domain points that can be constructed is (N+M)×S×Z p Among them, (N+M)×S time domain samples are obtained by sampling the (N+M) modulation symbols in the fourth symbol sequence, and the other (N+M)×(Z p -1) time domain samples are obtained by inserting zeros in the frequency domain. It can be understood that Z p A value of 1 indicates that zero insertion is not performed in the frequency domain, or that frequency domain interleaving is not performed. In other words, frequency domain interleaving is an optional step.

[0438] Method 2: After performing period extension on the fourth symbol sequence in the time domain, convert it into the frequency domain to perform RE mapping to obtain the second symbol sequence.

[0439] From the properties of Fourier transform, we can know that frequency domain interleaving is equivalent to time domain period extension, that is, the above (N+M)×S time domain samples are continuously repeated in the time domain. Starting from the starting position, each (N+M)×S time domain sample can be regarded as a cycle. The subcarrier offset Z p From the perspective of the time domain, this can also be referred to as the number of times the (N+M)×S time domain samples appear repeatedly. Those skilled in the art will appreciate that continuously repeating the (N+M)×S time domain samples in the time domain can achieve phase continuity.

[0440] Therefore, frequency domain interleaving can also be achieved by periodically extending the time domain. Repeatedly extend (N+M)×S time domain samples in the time domain (Z p -1) times, that is, the effect of frequency domain interleaving mentioned above can be achieved. Here, the number of repeated extensions refers to the number of times the (N+M)×S time domain samples appear again in addition to the original (N+M)×S time domain samples. In other words, if the repeated extension (Z p -1) times, a total of (N+M)×S×Z ptime domain sample points, or in other words, the number of times the time domain sample point is repeated is Z p times. (N+M)×S×Z p Convert the time domain samples to the frequency domain to get (N+M)×S×Z p Frequency domain samples, and then the (N+M)×S×Z p The frequency domain samples are RE mapped, and (N+M)×S×Z p Frequency domain samples are mapped to (N+M)×S×Z p REs, and thus the value mapped to each RE can be obtained. Therefore, another possible form of the second symbol sequence is (N+M)×S×Z p frequency domain samples.

[0441] Understandably, when Z p = 1, the (N + M) × S time domain samples do not need to be repeatedly extended in the time domain, or in other words, the number of repeated extensions is 0. The properties of the Fourier transform show that no periodic extension is required in the time domain, and no zero insertion is required in the frequency domain. In other words, no interleaving mapping is required, or in other words, mapping is performed in the frequency domain, but no interleaving is performed.

[0442] Since the second symbol sequence is used to generate the first OFDM baseband signal, the aforementioned (N+M)×S subcarriers are frequency domain resources used to transmit the first OFDM baseband signal.

[0443] Figures 11(a) and (b) respectively show two ways of mapping the symbols in the fourth symbol sequence to REs to obtain the second symbol sequence. In Figure 11(a), the terminal device converts the fourth symbol sequence to the frequency domain through Fourier transform, performs frequency domain interleaving and RE mapping, and obtains the value mapped to each RE, i.e., the second symbol sequence. In Figure 11(b), the terminal device obtains Z by performing time domain period extension on the fourth symbol sequence. p A fourth symbol sequence, and then the Z p The fourth symbol sequence is converted into the frequency domain and RE mapping is performed to obtain the second symbol sequence. For more details, please refer to the above and will not be repeated here.

[0444] Because the terminal device may allocate different resources for different amounts of transmitted data when processing the data to be transmitted, the number of repeated expansions of the time domain samples in different transmissions may also be different, and there may even be a situation where repeated expansion is not required, as shown in the above Z p When Z is 1, the time domain period extension step can be skipped or the terminal device can give Z based on the different times of repeated extension for the convenience of processing. pTherefore, regardless of whether the time domain sample points need to be repeatedly extended, the terminal device can perform the time domain period extension step, but the Z based on p The value of may be different.

[0445] Among them, Z p It may be predefined by the protocol, configured by the network device, or determined by the terminal device, and this application does not limit this.

[0446] If Z p The method further comprises: the terminal device receives first information from the network device, or the network device sends first information to the terminal device, the first information being used to indicate Z p The network device may indicate Z to the terminal device through the first information p , so that the terminal device can perform time domain cycle extension accordingly to transmit the first OFDM baseband signal through the corresponding resources. When the network device receives the first OFDM baseband signal from the terminal device, it can also obtain the first OFDM baseband signal accordingly.

[0447] If Z p is determined by the terminal device. Optionally, the method further includes: the terminal device sends first information to the network device, or the network device receives first information from the terminal device, the first information is used to indicate Z p The terminal device can also determine Z p For example, the terminal device can determine Z according to the frequency bandwidth allocated to the terminal device by the network device, the number of symbols to be transmitted N, the number of extended symbols M, the sampling rate S, etc. p , and then instructs the network device through the first information so that the network device uses the same parameters to de-RE map the first OFDM baseband signal.

[0448] In step 603, the terminal device generates a first OFDM baseband signal based on the second symbol sequence.

[0449] The terminal device can generate a first OFDM baseband signal based on the value on each RE obtained after RE mapping.

[0450] Exemplarily, the first OFDM baseband signal satisfies:

[0451] Where, satisfy:

[0452] in, represents the value mapped to RE(k, l) for antenna port p and subcarrier spacing configuration μ. In this embodiment, it may refer to the value of mapping (N+M)×S frequency domain samples to (N+M)×S subcarriers as described above; RE(k, l) represents the RE with frequency domain index k and time domain index l; the frequency domain index k may refer to the subcarrier index k, which is the index relative to the frequency domain reference point; the time domain index l may refer to the OFDM symbol index l, which is the index relative to the time domain reference point; Indicates the offset of the starting position of the OFDM symbol corresponding to the first OFDM baseband signal relative to the time domain reference point. Both the frequency domain reference point and the time domain reference point can be predefined. Δf represents the subcarrier spacing, μ represents the subcarrier spacing configuration, and μ and Δf satisfy: Δf = 2 μ 15 [kHz]; μ0 represents the maximum value of μ in the subcarrier spacing configuration configured by higher-layer parameters. Indicates the size of the resource grid, which can be represented by the number of RBs it contains; Indicates the starting position of the resource grid; Indicates the number of subcarriers in each RB; Indicates the pre-configured CP length, for example, the CP length configured by the 5G basic parameter set (numerology). c represents the basic time unit in NR. In a possible implementation of this embodiment, T c satisfy: in κ is a constant, for example, κ is the basic time unit T in LTE s The basic time unit T in NR c The ratio is 64.

[0453] The first OFDM baseband signal may include a signal body and a first CP. In this embodiment, the signal body may be generated by the second symbol sequence, and the first CP may be obtained by copying a portion (e.g., K1) of symbols at the end of the signal body to the beginning of the signal body. Since the second symbol sequence in this embodiment is obtained by mapping the (N+M) modulation symbols in the fourth symbol sequence to REs, the first OFDM baseband signal may also be said to be generated based on the fourth symbol sequence.

[0454] It should be understood that the generation of OFDM baseband signals can refer to various existing methods, such as the 4G standard, the 5G standard, or the future 6G standard, etc., and this application is not limited thereto. The above is only an example given in conjunction with the relevant sections of 3GPP TS 38.211 on OFDM baseband signal generation (OFDM baseband signal generation). For more details, please refer to the standard and will not be described in detail here.

[0455] In this embodiment, the length K1 of the first CP may be configured by the network device; or may be determined by the terminal device.

[0456] The terminal device can use the resources corresponding to the frequency bandwidth allocated by the network device to transmit the first OFDM baseband signal, that is, the bandwidth of the target frequency band is equal to the frequency bandwidth allocated by the network device. In this case, the length of the first CP corresponds to the frequency bandwidth allocated by the network device and can be configured by the network device.

[0457] Optionally, the method further includes: the terminal device receives third information from the network device, or the network device sends third information to the terminal device, where the third information is used to indicate the length of the first CP.

[0458] Exemplarily, the third information may directly indicate the value of K1, for example, the third information may include the value of K1, or other information that can be used to identify the value of K1. Alternatively, the third information may also indicate the bandwidth of the frequency band allocated to the terminal device. Since the ratio of the system bandwidth to the bandwidth of the frequency band allocated to the terminal device is equal to the ratio of the CP length corresponding to the system bandwidth to the CP length corresponding to the bandwidth of the frequency band allocated to the terminal device, or in other words, the ratio of the bandwidth of the frequency band allocated to the terminal device and its corresponding CP length is equal to the ratio of the system bandwidth and its corresponding CP length. The terminal device can calculate the length of the first CP based on the bandwidth of the frequency band allocated to the terminal device indicated in the third information, as well as the system bandwidth and its corresponding CP length.

[0459] It should be noted that the system bandwidth and the CP length corresponding to the system bandwidth can be indicated by existing signaling, for example, in 5G, it can be indicated by a basic parameter set (numerology) index. The system bandwidth and its corresponding CP length can also be indicated by a third information. In this case, in addition to indicating the bandwidth of the frequency band allocated to the terminal device, the third information can also indicate the system bandwidth and the CP length corresponding to the system bandwidth, or indicate other bandwidths different from the system bandwidth and their corresponding CP lengths. It should be understood that regardless of whether the third information indicates the system bandwidth and its corresponding CP length, other bandwidths and their corresponding CP lengths are scaled proportionally according to the system bandwidth and its corresponding CP length, and can be used to determine the length of the first CP in this application.

[0460] The terminal device may also use part of the resources in the frequency band allocated by the network device to transmit the first OFDM baseband signal, that is, the bandwidth of the target frequency band is smaller than the bandwidth of the frequency band allocated by the network device. In this case, the length of the first CP corresponds to the bandwidth of the target frequency band. The ratio of the system bandwidth to the bandwidth of the target frequency band is equal to the ratio of the CP length corresponding to the system bandwidth to the length of the first CP, or in other words, the ratio of the target frequency band to the length of the first CP is equal to the ratio of the system bandwidth to the length of the corresponding CP. The terminal device may determine the length of the first CP based on the ratio of the system bandwidth to the length of the CP corresponding to it, and the bandwidth of the target frequency band, and may notify the network device of the length of the first CP. The system bandwidth and its corresponding CP length may be configured by the network device, for example, indicated by a basic parameter set (numerology) index in 5G.

[0461] Optionally, the method further includes: the terminal device sending third information to the network device, or the network device receiving third information from the terminal device, where the third information is used to indicate the length of the first CP.

[0462] Exemplarily, the third information may directly indicate the value of K1, for example, the third information may include the value of K1, or other information that can be used to identify the value of K1. Alternatively, the third information may also indicate the bandwidth of the target frequency band, for example, the third information may include the bandwidth value of the target frequency band, or the third information may include information on the starting position and ending position of the target frequency band, etc. The starting position and ending position of the target frequency band may be absolute positions or relative positions relative to a preset reference point, which is not limited in this application.

[0463] The time domain resource of the first OFDM baseband signal can be an OFDM symbol, that is, the first OFDM baseband signal can be mapped to an OFDM symbol in the time domain. In other words, the above-mentioned fourth symbol sequence can be transmitted through a single OFDM symbol. In other words, the (N+M)×S time domain samples used to carry the fourth symbol sequence can be transmitted through a single OFDM symbol, and the transmission duration of each time domain sample is: 1 / [(N+M)×S×Δf], where Δf is the subcarrier spacing and 1 / Δf is the duration of a single OFDM symbol.

[0464] Optionally, the subcarrier spacing is predefined by a protocol, or configured by a network device.

[0465] If the subcarrier spacing is configured by the network device, the method may optionally further include: the terminal device receiving seventh information from the network device, or the network device sending seventh information to the terminal device, where the seventh information is used to indicate the subcarrier spacing. By configuring the subcarrier spacing, the network device can implicitly indicate the duration of an OFDM symbol to the terminal device.

[0466] It should be noted that the subcarrier spacing can also be indicated by existing signaling, for example, in 5G, it can be indicated by a numerology index. In other words, the numerology index can indicate the system bandwidth, the CP length corresponding to the system bandwidth, and the subcarrier spacing.

[0467] Based on the aforementioned steps 601 to 603 , the terminal device may generate and output a first OFDM baseband signal for subsequent operations.

[0468] In one possible implementation, steps 601 to 603 are implemented by a baseband chip in the terminal device.

[0469] As can be seen from the preceding steps 601 to 603, this application constructs a modulation symbol sequence with self-looping head and tail phases. This ensures phase continuity and a constant envelope between the CP sequence and the modulation symbol sequence, achieving a 0dB PAPR. The single-carrier modulation symbol sequence is then shifted and embedded into a given frequency domain resource. A CP that satisfies the length constraint is then added to ensure compatibility with OFDM technology, enabling interference-free coexistence.

[0470] It should be noted that the aforementioned RE mapping is used to determine which subcarriers are mapped to the samples in the frequency domain converted from the (N+M) modulation symbols in the fourth symbol sequence, without considering the frequency domain resources of the first CP. This is because the subcarriers to which the RE mapping is mapped are also the subcarriers used to transmit the first OFDM baseband signal. After the first OFDM baseband signal is generated, the terminal device can directly use these subcarriers to transmit the first CP. The first CP only occupies different resources from the signal body in the time domain, that is, the first CP is located before the signal body, and this can be achieved through the OFDM baseband signal generation formula (such as Formula 3 above). Therefore, in this embodiment, the object of RE mapping is the samples corresponding to the (N+M) modulation symbols in the frequency domain, and does not include the first CP, nor the symbols used to generate the first CP (such as the K1 modulation symbols at the end of the (N+M) modulation symbols, which can be referred to as the first CP sequence) or its corresponding samples in the frequency domain. In other words, there is no need to perform RE mapping on the first CP, the first CP sequence, and its corresponding samples in the frequency domain. In other words, neither the fourth symbol sequence nor the second symbol sequence includes the first CP or the first CP sequence. Therefore, even if a modulation scheme that can ensure phase continuity, such as CPM or LFM, is used, if the first symbol sequence is not spread and modulation is performed directly based on the first symbol sequence, a phase-continuous first OFDM baseband signal cannot be obtained.

[0471] In step 604, the terminal device outputs a passband signal based on the first OFDM baseband signal.

[0472] The terminal device (for example, a radio frequency chip in the terminal device) can move the first OFDM baseband signal to a target frequency band to facilitate transmission. For example, the target frequency band can refer to a portion of the frequency band allocated by the network device to the terminal device for use. For example, the terminal device determines a portion of the frequency band for data transmission based on the frequency band allocated by the network device. Alternatively, the target frequency band can be the entire frequency band allocated by the network device to the terminal device for use. This application is not limited to this.

[0473] In step 603, the terminal device has mapped the (N+M) modulation symbols in the fourth symbol sequence to the frequency domain resources in the baseband through RE mapping, that is, determined the relative position of the frequency domain resources of the first OFDM baseband signal. After determining the position of the target frequency band, the terminal device can determine the absolute position of the frequency domain resources of the first OFDM baseband signal based on the center frequency of the target frequency band, and then perform up-conversion.

[0474] Optionally, before step 604, the method further includes: the terminal device determining the absolute position of the frequency domain resources of the first OFDM baseband signal.

[0475] Since the frequency domain resources of the first OFDM baseband signal include (N+M)×S subcarriers, and the (N+M)×S subcarriers may be continuous or discontinuous, the center position of the frequency domain resources is found and aligned with the center frequency of the target frequency band, thereby determining the absolute position of the frequency domain resources used to transmit the first OFDM baseband signal.

[0476] Exemplarily, if the (N+M)×S subcarriers are continuous and (N+M)×S is an odd number, then the center position of the (N+M)×S subcarriers is the center frequency of the subcarrier with the middle number (i.e., the median number), that is, starting from 1, the center frequency of the ((N+M)×S+1) / 2th subcarrier in the (N+M)×S subcarriers. If the (N+M)×S subcarriers are continuous and (N+M)×S is an even number, then the center position of the (N+M)×S subcarriers is the average value of the sum of the frequencies of the two adjacent subcarriers with the middle number, that is, starting from 1, the average value of the sum of the frequencies of the (N+M)×S / 2th subcarrier and the ((N+M)×S / 2+1)th subcarrier in the (N+M)×S subcarriers. If the (N+M)×S subcarriers are discontinuous, the total number of subcarriers between the first subcarrier and the last subcarrier in the (N+M)×S subcarriers can be determined first, and then the center position can be determined according to the total number of subcarriers. Specifically, it can be processed according to the case where the total number of subcarriers is an odd number or an even number respectively. The specific processing method can be referred to above and will not be repeated here.

[0477] Among them, the position of the target frequency band can be determined according to the position of the frequency band allocated to the terminal device by the network device. For example, the target frequency band can be the frequency band allocated to the terminal device by the network device. In this case, the positions of the two are the same; the target frequency band can also be part of the bandwidth of the frequency band allocated to the terminal device by the network device. In this case, the position of the target frequency band is within the position of the frequency band allocated to the terminal device by the network device. It can be determined by the terminal device itself or indicated by the network device. This application does not limit this.

[0478] The location of the frequency band allocated by the network device to the terminal device can be indicated by the network device through signaling. Optionally, the method also includes: the network device sends eighth information to the terminal device, or the terminal device receives eighth information from the network device, and the eighth information is used to indicate the location of the frequency band allocated by the network device to the terminal device.

[0479] After determining the absolute position of the frequency domain resource, the terminal device may perform step 604 to move the first OFDM baseband signal to the target frequency band.

[0480] A possible implementation of step 604 is that the terminal device directly frequency modulates the carrier based on the first OFDM baseband signal to obtain a bandpass signal.

[0481] In the embodiment of the present application, since the first OFDM baseband signal is generated based on the second symbol sequence, and the second symbol sequence is obtained by mapping (N+M) modulation symbols obtained by phase or frequency modulation such as CPM or LFM to REs, the phase or frequency modulation is intended to modulate the information to be transmitted in phase or frequency rather than carrying information by amplitude. Therefore, the baseband signal can be converted to a bandpass signal by direct frequency modulation, that is, up-conversion is achieved. Since the signal obtained by direct frequency modulation can be called a frequency-modulated signal, the bandpass signal obtained by up-conversion by direct frequency modulation is a frequency-modulated signal.

[0482] Direct frequency modulation is used for up-conversion. For example, PLL, VCO, DCO and other devices that can generate frequency-adjustable sine waves can be used to achieve this. Compared with the transmitter architecture shown in Figure 3, this can avoid the frequency band shifting of the signal achieved by the mixer in I / Q modulation, save power consumption, and simplify the circuit structure, thereby reducing costs.

[0483] Of course, the implementation of up-conversion is not limited to direct frequency modulation. In another possible implementation, the terminal device uses I / Q modulation technology to up-convert the first OFDM baseband signal to obtain a bandpass signal.

[0484] Exemplarily, if I / Q modulation technology is desired, the first OFDM baseband signal generated by the terminal device can be an I-path baseband signal and a Q-path baseband signal. That is, the first OFDM baseband signal generated by the terminal device in step 603 is not limited to the form calculated by formula 3. The terminal device can directly generate the I-path baseband signal and the Q-path baseband signal based on the second symbol sequence in step 603, or can obtain the I-path baseband signal and the Q-path baseband signal by mathematical transformation (for example, taking the real part and imaginary part of the baseband signal in formula 3, respectively) based on the second symbol sequence. This application is not limited to this.

[0485] Accordingly, in step 604, after the I and Q baseband signals are output from the baseband chip to the upconversion module, they are mixed by the I and Q mixers, respectively, to achieve frequency band shifting. After superposition, a bandpass signal is obtained. In this case, the terminal device can use, for example, a PLL, VCO, or DCO, along with a mixer to achieve upconversion. Compared to direct frequency modulation, this involves more components, resulting in higher circuit complexity, higher transmit power consumption, and higher cost.

[0486] In step 605, the terminal device performs power amplification on the bandpass signal to obtain a power-amplified bandpass signal.

[0487] As mentioned above, power amplification can include linear power amplification or nonlinear power amplification. Combining the three different transmitter structures shown in Figure 4 above, it can be seen that the power amplification of the bandpass signal in this application can adopt linear power amplification or nonlinear power amplification.

[0488] For example, direct frequency modulation is used in step 604, and linear power amplification or nonlinear power amplification is used in step 605. Another example is that I / Q modulation is used in step 604, and nonlinear power amplification is used in step 605. All of the above examples can reduce transmit power by at least one of up-conversion and power amplification.

[0489] In a possible implementation, step 604 and step 605 may be implemented by a radio frequency chip in the terminal device.

[0490] In step 606, the terminal device transmits the power-amplified bandpass signal, and the network device receives the power-amplified bandpass signal.

[0491] The terminal device can transmit a power-amplified bandpass signal via a transmitting antenna. The network device can receive the bandpass signal from the terminal device via a receiving antenna. It is understood that the bandpass signal received by the network device is the bandpass signal transmitted by the terminal device after power amplification.

[0492] It should be understood that the steps 601 to 606 above are merely examples and do not limit the operations performed by the terminal device. The terminal device may also perform other operations in addition to the aforementioned operations, such as performing channel coding and modulation before acquiring the first symbol sequence; performing digital-to-analog conversion before outputting the first OFDM baseband signal; performing filtering and gain adjustment before outputting the first OFDM baseband signal, etc. This application does not limit these operations.

[0493] It should also be understood that during signal transmission from a terminal device to a network device, signals may be distorted due to external interference or suboptimal wireless channel quality, potentially resulting in a certain bit error rate. Therefore, the first symbol sequence, second symbol sequence, third symbol sequence, and extended symbols described herein may be different symbol sequences in the terminal device and the network device. For ease of understanding and explanation, the symbol sequences in different processing stages are given the same names.

[0494] In order to better understand the method provided by the present application, the following will combine the several different transmitter structures shown in Figure 4 to illustrate the processing process of the terminal device from obtaining the first symbol sequence to sending the bandpass signal. As shown in (a) in Figure 12A, after obtaining the first symbol sequence to be transmitted, the terminal device first expands the first symbol sequence, determines the third symbol sequence, and then modulates the third symbol sequence to obtain a fourth symbol sequence. As mentioned above, the fourth symbol sequence obtained by modulating the third symbol sequence is a continuous symbol sequence, and after sampling, a plurality of discrete time domain samples can be obtained. For the sake of simplicity, the continuous fourth symbol sequence and the discrete fourth symbol sequence are not distinguished in the following text and the accompanying drawings. It can be understood that whether it is a continuous fourth symbol sequence or a discrete fourth symbol sequence, it can be collectively referred to as a fourth symbol sequence. The terminal device can perform a Fourier transform on the fourth symbol sequence, convert the fourth symbol sequence to the frequency domain, and then perform RE mapping to obtain a second symbol sequence. The terminal device can generate a first OFDM baseband signal based on the second symbol sequence. After the baseband processing described above yields the first OFDM baseband signal, the terminal device can directly frequency modulate the carrier based on the first OFDM baseband signal to output a bandpass signal, then power amplify the bandpass signal and transmit the amplified bandpass signal through a transmitting antenna. The power amplification may include nonlinear power amplification or linear power amplification.

[0495] The process shown in (b) of Figure 12A is similar to that of (a) of Figure 12A , except for the method for obtaining the fourth symbol sequence. After obtaining the first symbol sequence to be transmitted, the terminal device first extends the first symbol sequence to determine a third symbol sequence. It then modulates and samples the N symbols to be transmitted and the M extended symbols in the third symbol sequence, respectively, to obtain N modulation symbols and M modulation symbols. These N modulation symbols and M modulation symbols are concatenated to obtain the fourth symbol sequence. Subsequent operations are the same as those in (a) of Figure 12A and will not be repeated here.

[0496] The Fourier transform and RE mapping operations shown in (a) and (b) of Figure 12A correspond to (a) in Figure 11. It is understood that the Fourier transform and RE mapping operations shown in (a) and (b) of Figure 12A can also be replaced by (b) in Figure 11, that is, after performing time domain period extension on the fourth symbol sequence, Fourier transform is then converted to the frequency domain, and then RE mapping is performed. As shown in (a) and (b) of Figure 12B, the specific operations in the figure can be referred to the previous description and will not be repeated here.

[0497] In FIG12A (a) and (b), and FIG12B (a) and (b), expansion may correspond to step 6021 above, modulation, sampling, and splicing may correspond to step 6022 above, Fourier transform, frequency domain interleaving, and RE mapping may correspond to method 1 in step 6023 above, time domain period extension, Fourier transform, and RE mapping may correspond to method 2 in step 6023 above, OFDM baseband signal generation may correspond to step 603 above, direct frequency modulation may correspond to step 604 above, and nonlinear / linear power amplification may correspond to step 605 above. For each operation in the figure, please refer to the relevant description of the corresponding step above and will not be repeated here.

[0498] It should be understood that the processing procedures shown in (a) and (b) of Figure 12A and (a) and (b) of Figure 12B are applicable to (a) and (c) of Figure 4. The difference between (a) and (c) of Figure 4 lies in the power amplifier. In (a) of Figure 4, the power amplifier is a nonlinear power amplifier, so in the processing procedures shown in (a) and (b) of Figure 12A and Figure 12B, the linear / nonlinear power amplification can specifically be nonlinear power amplification; in (c) of Figure 4, the power amplifier is a linear power amplifier, so in the processing procedures shown in (a) and (b) of Figure 12A and Figure 12B, the linear / nonlinear power amplification can specifically be linear power amplification.

[0499] The processing procedures shown in (a) and (b) of FIG. 13A and (a) and (b) of FIG. 13B are applicable to (b) of FIG. 4 . The difference between (b) and (a) of FIG. 4 lies in the different devices used for up-conversion. The specific processing methods of up-conversion shown in (a) and (b) of FIG. 13A and (a) and (b) of FIG. 13B are also different from the specific processing methods of up-conversion shown in (a) and (b) of FIG. 12A and (a) and (b) of FIG. 12B. The specific processing method of up-conversion shown in (a) and (b) of FIG. 12A and (a) and (b) of FIG. 12B is direct frequency modulation, where the input is the first OFDM baseband signal and the output is a bandpass signal (or a frequency-modulated signal). The specific processing method of the up-conversion shown in (a) and (b) of Figure 13A and (a) and (b) of Figure 13B is I / Q modulation, the input is the I-channel baseband signal and the Q-channel baseband signal, and the output is a bandpass signal. The I-channel baseband signal and the Q-channel baseband signal are obtained based on the first OFDM baseband signal. The specific generation method has been described above and will not be repeated here. Other operations are the same as those in (a) and (b) of Figure 12A and (a) and (b) of Figure 12B and will not be repeated here.

[0500] In step 607, the network device obtains a first OFDM baseband signal based on the passband signal.

[0501] The network device (specifically, a radio frequency chip in the network device) can down-convert the received bandpass signal to obtain a first OFDM baseband signal. The process of down-converting the received bandpass signal by the network device can be implemented using existing down-conversion technology, and this application does not limit this.

[0502] For example, in a RAN deployed with a CU, DU, and RU, steps 606 and 607 may be specifically implemented as follows: the RU receives the passband signal and forwards the received passband signal to the DU for processing to obtain a first OFDM baseband signal; in an ORAN, steps 606 and 607 may be specifically implemented as follows: the O-RU receives the passband signal and forwards the passband signal to the O-DU for processing after partial physical layer processing to obtain a first OFDM baseband signal.

[0503] After downconverting the first OFDM baseband signal, the network device's radio frequency chip can output the first OFDM baseband signal to the network device's baseband chip for further processing. Optionally, the network device can also perform noise suppression on the received passband signal before downconversion. For example, the network device can use a low-noise amplifier (LNA) to suppress noise, thereby outputting a signal with a high signal-to-noise ratio (SNR). The specific process of using an LNA for noise suppression can be found in existing technologies and is not described in detail here.

[0504] In step 608, the network device obtains a fourth symbol sequence based on the first OFDM baseband signal.

[0505] The network device (specifically, the baseband chip in the network device) can sample the first OFDM baseband signal from the radio frequency chip to obtain a discrete signal. In this embodiment, ((N+M)×S×Z) can be obtained. p +K1×S) time domain samples. Since the CP of the first OFDM baseband signal (i.e., the first CP) is the K1 symbols at the end of the signal body of the first OFDM baseband signal, the ((N+M)×S×Z) obtained by sampling p +K1×S) time domain samples include two parts corresponding to the signal body and the first CP, that is, Z p The network device can obtain the fourth symbol sequence from the first OFDM baseband signal, where S is the sampling rate, Z is the sampling rate, p It is the subcarrier offset between two adjacent comb teeth in the frequency domain, or the number of times the time domain sample point is repeated.

[0506] For example, in a RAN deployed with CU, DU, and RU, the specific implementation of step 608 may be: the DU obtains a fourth symbol sequence based on the first OFDM baseband signal; in an ORAN, the specific implementation of step 608 may be: the O-DU obtains a fourth symbol sequence based on the first OFDM baseband signal.

[0507] Optionally, step 608 specifically includes:

[0508] Step 6081: The network device obtains Z based on the first OFDM baseband signal. p a fourth symbol sequence;

[0509] The network device (specifically, the baseband chip in the network device) can sample the first OFDM baseband signal from the radio frequency chip to obtain a discrete signal. In this embodiment, ((N+M)×S×Z) can be obtained. p +K1×S) time domain samples. Since the CP of the first OFDM baseband signal (i.e., the first CP) is the K1 symbols at the end of the signal body of the first OFDM baseband signal, the ((N+M)×S×Z) obtained by sampling p +K1×S) time domain samples include two parts corresponding to the signal body and the first CP, that is, Z p a fourth symbol sequence and a first CP sequence.

[0510] Step 6082, the network device from the Z p A fourth symbol sequence is obtained from a fourth symbol sequence.

[0511] For example, the network device may remove the first CP sequence according to the length of the first CP to obtain Z p A fourth symbol sequence is obtained by performing RE demapping. The fourth symbol sequence thus obtained includes L modulation symbols, where L=M+N. That is, the L modulation symbols include (M+N) modulation symbols obtained by modulating the third symbol sequence consisting of N symbols to be transmitted and M extended symbols.

[0512] As mentioned above, the length of the first CP can be configured by the network device, or determined by the terminal device and indicated to the network device. Therefore, the network device can predetermine the length of the first CP and then obtain the second symbol sequence based on the length of the first CP.

[0513] Corresponding to the implementation of the terminal device in step 6023 above, in step 6082, the network device can p The fourth symbol sequence is converted into the frequency domain to obtain the fourth symbol sequence by de-RE mapping and frequency domain de-interleaving, or de-periodization or period merging is directly performed in the time domain to obtain the fourth symbol sequence.

[0514] The following describes step 6082 in detail using two different methods.

[0515] Method 1: Z in the time domain p The fourth symbol sequences are de-periodized or period-combined to obtain a fourth symbol sequence.

[0516] In this embodiment, Z p It can be 1 or greater than 1. pA value of 1 indicates that in step 6023 above, the terminal device did not perform time domain period extension on the fourth symbol sequence, or did not perform interleaving on (N+M)×S frequency domain samples in the frequency domain. p A value greater than 1 indicates that in the previous step 6023, the terminal device has repeatedly extended the fourth symbol sequence at least once, or interleaved (N+M)×S frequency domain samples in the frequency domain.

[0517] Correspondingly, in Z p When Z is greater than 1, the network device can p The fourth symbol sequences are de-periodized in the time domain or combined in the time domain to obtain a fourth symbol sequence.

[0518] Among them, time domain de-periodization specifically refers to, from Z p Remove (Z p -1) cycles, or in other words, keep Z p A complete cycle in the cycles is used to obtain the fourth symbol sequence. p The application does not limit which cycle to retain. Time domain cycle merging specifically refers to the Z p The corresponding time domain samples in the periods are combined by taking an average value, a weighted average value, etc., to obtain a complete period as the fourth symbol sequence. p The corresponding time domain sample points in a cycle can be understood as follows: if the Z p The (N+M)×S sample points in each cycle are numbered separately, Z p The sample points with the same number in the period are Z p It can be understood that period merging combines the time domain samples in multiple periods, so it has a higher gain than de-periodization.

[0519] In Z p When it is equal to 1, the fourth symbol sequence can be obtained by removing the first CP sequence, and time domain de-periodization or cycle merging can be skipped.

[0520] Since the network equipment processes the OFDM baseband signal, the number of repeated expansions of the time domain samples in the OFDM baseband signal obtained at different times may be different, that is, Z p The value of may be different. The network device may need to perform time domain de-periodization or cycle merging, or it may not need to perform time domain de-periodization or cycle merging. As mentioned above, Z p It can be configured by the network device or determined by the terminal device, so the network device can obtain the Z in advance. p, and then determine whether to perform time domain de-periodization or period merging.

[0521] Understandably, in Z p When Z is greater than 1, the network device may obtain the fourth symbol sequence by executing steps 6081 and 6082; p When it is equal to 1, the network device can directly obtain the fourth symbol sequence through step 6081, and step 6082 can be skipped.

[0522] Method 2: Z p The fourth symbol sequence is converted to the frequency domain, de-RE mapped and frequency domain de-interleaved, and then converted back to the time domain to obtain the fourth symbol sequence.

[0523] Due to the characteristics of Fourier transform, time domain period extension is equivalent to frequency domain interleaving. Correspondingly, time domain de-periodization or time domain period merging is also equivalent to frequency domain de-interleaving. p When it is greater than 1, the network device obtains Z p After the fourth symbol sequence is obtained, it can also be converted to the frequency domain, and after completing RE mapping and frequency domain deinterleaving in the frequency domain, it is converted back to the time domain to obtain the fourth symbol sequence. p When it is equal to 1, frequency domain deinterleaving can also be skipped.

[0524] Understandably, in Z p When Z is greater than 1, the network device may obtain the fourth symbol sequence by executing steps 6081 and 6082; p When it is equal to 1, the network device can obtain the fourth symbol sequence through step 6081, and the network device can perform RE demapping when executing 6082 without performing frequency domain deinterleaving.

[0525] In step 609, the network device performs demodulation based on the fourth symbol sequence to obtain a third symbol sequence.

[0526] Exemplarily, in a RAN deployed with CU, DU, and RU, the specific implementation of step 609 may be: the DU demodulates based on the fourth symbol sequence to obtain a third symbol sequence; in an ORAN, the specific implementation of step 609 may be: the O-DU demodulates based on the fourth symbol sequence to obtain a third symbol sequence.

[0527] As explained in step 6022, the fourth symbol sequence is obtained by the terminal device through modulation based on the third symbol sequence, so the network device can use a corresponding demodulation method to demodulate the fourth symbol sequence to obtain the third symbol sequence.

[0528] Exemplarily, corresponding to the modulation mode of the terminal device, the demodulation mode of the fourth symbol sequence of the network device includes: CPM demodulation or LFM demodulation. The specific method for the network device to demodulate the fourth symbol sequence can be determined by the network device itself. The network device can use CPM demodulation or LFM demodulation for demodulation, or other methods for demodulation. For example, those skilled in the art can make simple transformations based on the same concept to achieve the same effect on the basis of CPM demodulation or LFM demodulation. For example, taking CPM demodulation as an example, the demodulation of the phase domain is converted to other domains, and then converted back to the phase domain after the demodulation is completed. In essence, CPM demodulation is still completed, or in other words, it is essentially the same as CPM demodulation, and so on, which will not be repeated.

[0529] Optionally, before step 609, the method further includes: the network device performing channel equalization.

[0530] Channel equalization is based on the channel estimated by the channel, and uses an equalization algorithm to remove the influence of the channel to ensure correct signal demodulation. Channel equalization can include channel equalization in the frequency domain (also referred to as frequency domain equalization) or channel equalization in the time domain (also referred to as time domain equalization). In other words, network devices can perform channel equalization in the frequency domain, that is, using a frequency domain equalization algorithm to remove the influence of the channel, or they can perform channel equalization in the time domain, that is, using a time domain equalization algorithm to remove the influence of the channel.

[0531] For example, when the network device executes step 6082, if the fourth symbol sequence is obtained by time domain deperiodization or time domain period merging, the time domain equalization algorithm can be directly used for channel equalization, thereby avoiding the computational complexity associated with time-frequency domain conversion and saving power. Of course, the network device can also convert the signal to the frequency domain, use the frequency domain equalization algorithm, perform channel equalization in the frequency domain, and then convert back to the time domain.

[0532] For another example, when executing step 6082, the network device obtains the fourth symbol sequence through frequency domain deinterleaving. The network device may also convert the first OFDM baseband signal to the frequency domain, perform channel equalization using a frequency domain equalization algorithm, and then convert back to the time domain after completing the frequency domain deinterleaving.

[0533] In step 610, the network device obtains the first symbol sequence from the third symbol sequence.

[0534] Exemplarily, in a RAN deployed with CU, DU, and RU, the specific implementation of step 610 may be: the DU obtains the first symbol sequence from the third symbol sequence; in an ORAN, the specific implementation of step 610 may be: the O-DU obtains the first symbol sequence from the third symbol sequence.

[0535] As described in step 602 above, the third symbol sequence includes N symbols to be transmitted and M extended symbols. The third symbol sequence obtained by the network device from the second symbol sequence also includes L symbols. The L symbols include: N symbols corresponding to the N symbols to be transmitted (for ease of distinction, denoted as N first symbols) and M extended symbols added to obtain a constant envelope waveform. The network device can obtain the first symbol from the third symbol sequence based on the position of the M extended symbols in the third symbol sequence and the value of M.

[0536] Optionally, step 610 includes:

[0537] Step 6101: The network device determines the value of M.

[0538] Step 6102: The network device determines positions of the M extended symbols in the third symbol sequence.

[0539] Step 6103: The network device obtains the first symbol sequence from the third symbol sequence.

[0540] The value of M may be predefined by the protocol, or may be configured by the network device, or may be determined by the terminal device. If the value of M is predefined by the protocol or configured by the network device, the network device may know the value of M in advance, and the value of M may be pre-stored in the memory (such as a cache) of the network device. When executing step 6101, the network device may determine the value of M by reading data in the memory; if the value of M is determined by the terminal device, when executing step 6101, the network device may parse the value of M from the sixth information received from the terminal device.

[0541] One possible scenario is that the value of M is zero, that is, L = N, and the L symbols obtained by the network device based on demodulation of the second symbol sequence are all the N first symbols that the terminal device wishes to transmit. When the network device executes step 6103, it can determine the third symbol sequence as the first symbol sequence based on the value of M being zero, without having to execute step 6102. It should be understood that in this case, step 609 and step 6103 can also be considered the same step, and step 6101 can be executed before step 609.

[0542] Another possible scenario is that the value of M is not zero, that is, M>0, L>N, and the L symbols obtained by the network device based on demodulation of the second symbol sequence include N first symbols and M extended symbols. When the network device executes step 6103, it can remove the M extended symbols from the third symbol sequence based on the value of M and the positions of the M extended symbols in the third symbol sequence to obtain N first symbols, that is, obtain the first symbol sequence.

[0543] The positions of the M extended symbols in the third symbol sequence may be predefined by a protocol, or may be configured by a network device, or may be determined by a terminal device. If the positions of the M extended symbols in the third symbol sequence are predefined by a protocol or configured by a network device, the network device may predict the positions of the M extended symbols in the third symbol sequence. When the network device executes step 6102, the positions of the M extended symbols in the third symbol sequence may be determined by reading data in a memory. If the positions of the M extended symbols in the third symbol sequence are determined by a terminal device, the network device may execute step 6102 and determine the positions of the M extended symbols in the third symbol sequence by parsing information received from the terminal device (such as the fifth information).

[0544] For example, assuming that M is 1 and the position of the M extended symbols in the third symbol sequence is after the N first symbols, the network device can remove the last symbol in the third symbol sequence, and the resulting N symbols are the N first symbols, which can constitute the first symbol sequence.

[0545] The possible positions of the M extended symbols in the third symbol sequence have been described in detail in the above steps and will not be repeated here. Regardless of the position of the M extended symbols in the third symbol sequence, the network device can remove them from the third symbol sequence to obtain the first symbol sequence. For the sake of brevity, examples are not given here one by one.

[0546] In a possible implementation, steps 608 to 610 are implemented by a baseband chip in the network device.

[0547] In order to better understand the process of processing the received signal by the network device, the following diagram illustrates the process of the network device from receiving the passband signal to obtaining the first symbol sequence.

[0548] The processing processes shown in (a) and (b) in Figure 14 correspond to Figures 12A, 12B and 13A, 13B, and can be used to process the bandpass signal sent based on the processing process of any of Figures 12A, 12B, 13A or 13B.

[0549] As shown in (a) of Figure 14, after receiving the passband signal, the network device can first down-convert the received passband signal. After down-conversion, the passband signal is moved to the baseband to obtain the first OFDM baseband signal. After sampling the first OFDM baseband signal, ((N+M)×S×Z) can be obtained. p +K1×S) sample points (or time domain sample points), that is, Z pA fourth symbol sequence and a first CP sequence. After removing the CP sequence, after time domain de-periodization or period merging, the network device can obtain a fourth symbol sequence. Thereafter, the network device can demodulate the fourth symbol sequence to obtain a third symbol sequence, and then remove the M extended symbols from the third symbol sequence to obtain the first symbol sequence. Optionally, in order to ensure that the fourth symbol sequence is correctly demodulated, the network device can perform channel equalization before time domain de-periodization. The processing shown in (a) in Figure 14 is performed in the time domain, and the channel equalization can be time domain equalization.

[0550] In step 14 (a), down-conversion may correspond to step 607 above, sampling and CP sequence removal may correspond to step 6081 above, time domain equalization and time domain de-periodization / period merging may correspond to step 6082 above, demodulation may correspond to step 609 above, and extension symbol removal may correspond to step 610 above. For each operation in the figure, please refer to the relevant description of the corresponding steps above and will not be repeated here.

[0551] FIG14(b) is similar to FIG14(a), except that the operation of obtaining the fourth symbol sequence and channel equalization in step 6082 is converted to the frequency domain. p After the fourth symbol sequence is obtained, it can be converted to the frequency domain by Fourier transform, and then frequency domain equalization and frequency domain deinterleaving are performed, and then converted to the time domain by inverse Fourier transform to obtain the fourth symbol sequence. Among them, down-conversion can correspond to step 607 above, sampling and removing the CP sequence can correspond to step 6081 above, Fourier transform, de-RE mapping, frequency domain equalization, frequency domain deinterleaving and inverse Fourier transform can correspond to step 6082 above, demodulation can correspond to step 609 above, and removal of extended symbols can correspond to step 610 above. For other steps in (b) of Figure 14, please refer to the relevant description of (a) of Figure 14 and the corresponding steps above, and will not be repeated here.

[0552] Based on the above technical solution, the first symbol sequence is expanded to obtain a third symbol sequence, which is then modulated and RE-mapped based on the third symbol sequence to obtain a second symbol sequence. The resulting second symbol sequence simultaneously meets the following requirements: phase continuity and self-looping of the first and last phases. The first OFDM baseband signal generated based on this second symbol sequence also meets phase continuity between the signal body and the CP. Based on this, if the modulation technique employed is one that maintains constant amplitude, a waveform with continuous phase and a constant envelope can be obtained. This allows for a solution that combines phase or frequency modulation with OFDM to achieve a constant envelope waveform. Because the constant envelope waveform meets the waveform requirements of direct frequency conversion and nonlinear power amplification, communication devices can use more power-efficient methods for signal transmission. This improves the standby life of communication devices (particularly small IoT nodes that do not carry large batteries). Furthermore, the RE mapping and OFDM baseband signal generation steps in the terminal device are consistent with current standards, ensuring good compatibility.

[0553] After receiving the passband signal and demodulating it to obtain the third symbol sequence, the network device can derive the first symbol sequence from the third symbol sequence based on the number of extended symbols and their positions within the third symbol sequence, thereby allowing the first symbol sequence to be received. As can be seen, the processing performed by the network device after receiving the passband signal does not require significant changes compared to the current processing, thus achieving better compatibility.

[0554] The above text, in conjunction with Figures 6 to 14, illustrates an embodiment provided by the present application. In this embodiment, the generation of the first OFDM baseband signal is substantially consistent with the definition in the current 3GPP standard, and has good compatibility. As can be seen from the properties of the Fourier transform, the signal processing process in the frequency domain can also be converted to the time domain. For example, RE mapping can also be accomplished by periodic extension in the time domain, and the generation of the OFDM baseband signal can also be accomplished in the time domain. This can eliminate operations such as Fourier transform and inverse transform, thereby reducing the amount of computation and further saving power consumption. Another possible embodiment of the communication method provided by the present application will be described in detail below.

[0555] FIG15 is a schematic flowchart of a communication method provided in another embodiment of the present application.

[0556] The method 1500 shown in Figure 15 may include steps 1501 to 1510. Steps 1501 to 1506 are processes performed by the terminal device, and steps 1506 to 1510 are processes performed by the network device. Exemplarily, steps 1501 to 1503 may be performed by the baseband chip of the terminal device, step 1504 may be performed by the up-conversion module of the terminal device, step 1505 may be performed by the power amplifier of the terminal device, and the sending operation in step 1506 may be performed by the antenna of the terminal device (such as a transmitting antenna). The receiving operation in step 1506 may be performed by the antenna of the network device (such as a receiving antenna), step 1507 may be performed by the down-conversion module of the network device, and steps 1508 to 1510 may be performed by the baseband chip of the network device.

[0557] The various steps in method 1500 are described in detail below.

[0558] In step 1501, a terminal device obtains a first symbol sequence, where the first symbol sequence includes N symbols to be transmitted.

[0559] The detailed description of step 1501 can be found in step 601 of method 600 above, which will not be repeated for the sake of brevity.

[0560] In step 1502, the terminal device generates a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the first symbol sequence.

[0561] Different from method 600, before generating the first OFDM baseband signal, the terminal device may pre-generate a first CP sequence corresponding to the first CP, and then generate the first OFDM baseband signal based on the fourth symbol sequence and the first CP sequence.

[0562] In this embodiment, the terminal device can obtain a fourth symbol sequence by modulation. Similar to method 600, the modulation in this application is continuous phase modulation. Exemplarily, the modulation includes CPM or LFM. If the terminal device performs modulation directly based on the first symbol sequence, the phase of the generated OFDM baseband signal may jump, resulting in an unstable envelope. Therefore, the terminal device can add a number (such as M) of extended symbols on the basis of the first symbol sequence, and realize the self-circulation of the head and tail phases of the second symbol sequence by designing the extended symbols, thereby making the phase of the OFDM baseband signal generated based on the second symbol sequence continuous.

[0563] M may be an integer greater than or equal to zero. When M is zero, the third symbol sequence is the same as the first symbol sequence; when M is greater than zero, the third symbol sequence is different from the first symbol sequence. The third symbol sequence is obtained by adding one or more extended symbols to the first symbol sequence while maintaining the order of the N symbols to be transmitted.

[0564] Optionally, step 1502 includes:

[0565] The terminal device determines a third symbol sequence based on the first symbol sequence; and

[0566] The terminal device generates a fourth symbol sequence and a first CP sequence located before the fourth symbol sequence based on the third symbol sequence.

[0567] The specific process of the terminal device determining the third symbol sequence based on the first symbol sequence can be found in the relevant description of step 6021 in the above method 600, and will not be repeated for the sake of brevity.

[0568] The process of the terminal device generating the fourth symbol sequence and the first CP sequence based on the third symbol sequence mainly includes: modulation, CP sequence generation and RE mapping. Among them, modulation includes modulation based on the third symbol sequence, and the modulated output includes the fourth symbol sequence; RE mapping is to map each modulation symbol in the fourth symbol sequence to RE to obtain the value carried on each RE. In this embodiment, RE mapping is achieved by time domain period extension; CP sequence generation is to generate a first CP sequence located before the fourth symbol sequence, and the first CP sequence includes K1 modulation symbols, corresponding to the K1 symbols at the end of the third symbol sequence. Among them, modulation and CP sequence generation can be performed simultaneously or separately.

[0569] The process of the terminal device modulating the third symbol sequence can refer to the detailed description of the method 600 in combination with CPM and LFM, and the third symbol sequence is used as the input of CPM or LFM. Get the fourth symbol sequence For specific implementation, please refer to the previous Related description, replace a with That’s it, no more details.

[0570] (a), (b) and (c) in FIG. 16 show three possible implementations of step 1502 .

[0571] A possible implementation of step 1502 is shown in (a) of FIG16 , where the terminal device can modulate the third symbol sequence to obtain a fourth symbol sequence; after performing a time domain period extension on the fourth symbol sequence, Z is obtained. pThe fourth symbol sequence is added to the K1 modulation symbols at the end of the fourth symbol sequence. p Before the fourth symbol sequence (corresponding to the operation of adding the CP sequence in (a) of FIG16 ), Z is obtained. p The fourth symbol sequence and the p The first CP sequence before the fourth symbol sequence.

[0572] That is, the third symbol sequence is used as the modulation input and modulated. Since the third symbol sequence is determined based on the first symbol sequence, the fourth symbol sequence can satisfy the symbol sequence of the head and tail phase self-circulation. Therefore, the fourth symbol sequence is extended in the time domain period, and the obtained Z p The fourth symbol sequences are phase-continuous; the K1 modulation symbols at the end of the modulated fourth symbol sequence are added as a first CP sequence before the fourth symbol sequence, and the first CP sequence and the fourth symbol sequence are also phase-continuous.

[0573] Because the modulation symbols obtained by modulation are continuous, they must be sampled before they can be stored in a digital system. Therefore, after modulation, each modulation symbol can also be sampled. Sampling can be considered an independent operation, as shown in the figure, where sampling is performed after modulation. Alternatively, sampling can be considered part of modulation, in which case the sampling in the figure can be combined with modulation. This application is not limited to this.

[0574] Assuming that the sampling rate is S, where S is a positive integer, S samples are taken for each modulation symbol, and each modulation symbol can be recorded by the S samples obtained by sampling. Since the third symbol sequence includes (N+M) symbols, (N+M) modulation symbols can be obtained after modulation, so (N+M)×S samples can be obtained by sampling. In an embodiment of the present application, the fourth symbol sequence can refer to the continuous (N+M) modulation symbols obtained by modulation, or it can refer to the (N+M)×S samples obtained by sampling. The (N+M) modulation symbols and the (N+M)×S samples can be regarded as two different forms of the fourth symbol sequence.

[0575] Another possible implementation of step 1502 is shown in (b) of FIG16 , where the terminal device can modulate the N symbols to be transmitted and the M extended symbols in the third symbol sequence respectively to obtain N continuous modulation symbols and M continuous modulation symbols; insert the M modulation symbols into the N modulation symbols according to the positions of the M extended symbols in the third symbol sequence, and perform phase compensation on at least part of the N modulation symbols so that the phases of the (M+N) modulation symbols after the insertion of the M modulation symbols are continuous (which may correspond to the splicing operation in (b) of FIG16 ), thereby obtaining a fourth symbol sequence; perform time domain periodic extension on the fourth symbol sequence to obtain Zp After the fourth symbol sequence, K1 modulation symbols at the end of the fourth symbol sequence are added to Z p Before the fourth symbol sequence, we get Z p The fourth symbol sequence and the p The first CP sequence before the fourth symbol sequence.

[0576] Since the present application does not limit the position of the M modulation symbols in the third symbol sequence, the M modulation symbols can be continuous and located before or after the N symbols to be transmitted, or the M modulation symbols can be continuously or discretely distributed among the N symbols to be transmitted. Due to the phase accumulation characteristic of CPM itself, when the M modulation symbols are inserted into the N symbols to be transmitted, it is necessary to consider the phase continuity between the inserted M modulation symbols and the N modulation symbols, so phase compensation is required. The method for phase compensation of the fourth symbol can be found in the second implementation of step 6022 in method 600 above, combined with the example, and will not be repeated here.

[0577] Similar to FIG16(a), after modulating the N symbols to be transmitted and the M extended symbols, each modulated symbol obtained by the modulation may be sampled. Sampling may be considered an independent operation, as shown in the figure, where sampling is performed after modulation. Alternatively, sampling may be considered part of the modulation, in which case the sampling in the figure may be combined with the modulation, which is not limited in this application.

[0578] Another possible implementation of step 1502 is shown in FIG16(c). The terminal device may first perform a time domain period extension on the third symbol sequence to obtain Z p A third symbol sequence; add K1 symbols at the end of the third symbol sequence to Z p Before the third symbol sequence (corresponding to the operation of adding symbols in (c) of FIG. 16 ), an eighth symbol sequence is obtained; the eighth symbol sequence is modulated to obtain Z p The fourth symbol sequence and the p The first CP sequence before the fourth symbol sequence.

[0579] That is to say, before modulation, the symbols used to generate the first CP sequence are first added to the third symbol sequence. Since the symbols used to generate the first CP sequence are the K1 symbols at the end of the third symbol sequence, and the third symbol sequence can make the fourth symbol sequence meet the head and tail phase self-circulation, the K1 symbols at the end are added to Z p Before the third symbol sequence, the obtained eighth symbol sequence is modulated, and the obtained first CP sequence is phase-continuous with the fourth symbol sequence, Z pThe phases of the fourth symbol sequences are also continuous. In this implementation, although the first CP sequence is obtained by modulation based on the K1 symbols at the end of the third symbol sequence, it can be understood that the K1 modulation symbols at the end of the fourth symbol sequence are also obtained by modulation based on the K1 symbols at the end of the third symbol sequence. Therefore, the first CP sequence can also be considered to be the K1 modulation symbols at the end of the fourth symbol sequence.

[0580] Similar to FIG16(a), after the eighth symbol sequence is modulated, each modulated symbol obtained by the modulation may be sampled. Sampling may be considered an independent operation, as shown in the figure, where sampling is performed after modulation. Alternatively, sampling may be considered part of modulation, in which case the sampling in the figure may be combined with the modulation, which is not limited in this application.

[0581] Assuming that the sampling rate is S, the fourth symbol sequence obtained by modulating and sampling the eighth symbol sequence can be recorded by (N+M)×S sample points.

[0582] FIG17 shows an example of the eighth symbol sequence. In FIG17 , it is assumed that the third symbol sequence is: {a1, a2, a3, a ex}, where a1 to a3 are N symbols to be transmitted, a ex There are M extended symbols, and the M extended symbols are located after the N symbols to be transmitted. Assuming that the length of the first CP is K1=2, the two symbols at the end of the third symbol sequence can be copied and added to Z p Before the third symbol sequence, the eighth symbol sequence {a3, a ex , a1, a2, a3, a ex ,……,a1,a2,a3,a ex}.

[0583] It should be understood that FIG17 is only for the purpose of facilitating understanding and does not constitute any limitation to the present application. p etc. are not limited.

[0584] The above text shows three different implementations of step 1502 in conjunction with (a), (b) and (c) in Figure 16. In these implementations, the third symbol sequence or the fourth symbol sequence is respectively subjected to time domain cycle extension. In fact, as explained in step 6022 of method 600 above, the terminal device may not necessarily perform the time domain cycle extension operation, that is, Z p It can be equal to 1. Therefore, the time domain period extension operation in the figure is optional and can be skipped.

[0585] In addition, regardless of whether the third symbol sequence or the fourth symbol sequence is subjected to time domain period extension, the position of the first CP sequence is always at Zp Therefore, in step 1502, the terminal device may generate at least one fourth symbol sequence based on the third symbol sequence, and a first CP sequence located before the at least one fourth symbol sequence.

[0586] In step 1503, the terminal device generates a first OFDM baseband signal based on the fourth symbol sequence and the first CP sequence.

[0587] The process of generating an OFDM baseband signal can be understood as the process of generating a time domain signal. In this embodiment, the terminal device can generate the first OFDM baseband signal based on the value of each RE obtained after RE mapping and the first CP sequence. The specific process of step 1503 is described below using CPM and LFM as examples.

[0588] In one possible approach, the first OFDM baseband signal satisfy:

[0589] Among them, the value range of t' satisfies: Δf is the subcarrier spacing; is a periodic function with a period of (N+M)×T, and the expression for 0≤t'≤(N+M)×T is Represents the third symbol sequence The phase at time t, The value range of t satisfies: 0≤t≤(N+M)×T.

[0590] In formula 4, The CP representing the first OFDM baseband signal (i.e., the first CP) is located before the main body of the first OFDM baseband signal in the time domain. It is not difficult to see that the first OFDM baseband signal is continuous. For explanations of other parameters, please refer to the descriptions of Formulas 1 and 2 above and will not be repeated here.

[0591] It should be understood that Formula 4 is similar to Formula 1 shown in method 600, except that Formula 1 does not yet insert the first CP, while Formula 4 inserts the first CP at a time-domain position before the OFDM symbol. Formula 4 is merely an example, and those skilled in the art can perform simple transformations based on the same concept, such as shown in Formula 4.1 below.

[0592] Assume that Z generated in step 1502 p The fourth symbol sequence and the Z p The symbol sequence composed of the first CP sequence before the fourth symbol sequence is recorded as Based on the Z pThe first OFDM baseband signal generated by the fourth symbol sequence and the first CP sequence can satisfy:

[0593] in, Represents the third symbol sequence At the time t, the phase can be satisfied The value range of t satisfies: The description of other parameters can refer to the above description of formula 1 and formula 4, which will not be repeated here. It can be seen more directly from formula 4.1 that the first OFDM baseband signal is based on Z p The fourth symbol sequence and the first CP sequence are generated.

[0594] The parameters used by CPM, such as one or more of the frequency pulse shaping function of CPM, the phase pulse shaping function of CPM, the modulation index of CPM or the initial phase of CPM, can be configured by the network device or determined by the terminal device. This application does not limit this.

[0595] If the parameter is configured by the network device, the network device may indicate the parameter to the terminal device through the fourth information, so that the terminal device performs CPM based on the parameter indicated by the fourth information. Optionally, the method further includes: the terminal device receiving the fourth information from the network device, or the network device sending the fourth information to the terminal device, where the fourth information is used to indicate the modulation parameter.

[0596] If the parameter is determined by the terminal device, the terminal device may indicate the parameter to the network device through the fourth information, so that the network device performs CPM demodulation based on the parameter indicated by the fourth information. Optionally, the method further includes: the terminal device sending the fourth information to the network device, or the network device sending the fourth information to the terminal device, where the fourth information is used to indicate the modulation parameter.

[0597] In the case where the modulation mode is CPM, the modulation parameters may include, for example: at least one of the CPM frequency pulse shaping function g(t) or the CPM phase shaping function q(t), the CPM modulation index h and the CPM initial phase

[0598] In another possible approach, the first OFDM baseband signal s(t',a) baseband satisfy:

[0599] Among them, the value range of t' satisfies: is a periodic function with a period of (N+M)×T, and the expression for 0≤t'≤(N+M)×T is Represents the third symbol sequence At the phase at time t, the value range of t satisfies: 0≤t≤(N+M)×T. It is not difficult to see that the first OFDM baseband signal is continuous.

[0600] It should be understood that Formula 5 is similar to Formula 2 shown in method 600, except that Formula 2 does not insert the first CP, while Formula 5 inserts the first CP at a time-domain position before the OFDM symbol. Formula 5 is merely an example, and those skilled in the art can perform simple transformations based on the same concept, such as shown in Formula 5.1 below.

[0601] Assume that Z generated in step 1502 p The fourth symbol sequence and the Z p The symbol sequence composed of the first CP sequence before the fourth symbol sequence is recorded as Based on the Z p The first OFDM baseband signal generated by the fourth symbol sequence and the first CP sequence can satisfy:

[0602] in, Represents the third symbol sequence At the phase of time t, the value range of t satisfies: The description of other parameters can be found in the above description of formula 1 and formula 5, which will not be repeated here. It can be seen more directly from formula 5.1 that the first OFDM baseband signal is based on Z p The fourth symbol sequence and the first CP sequence are generated.

[0603] The parameters used by LFM, such as the bandwidth of the frequency band used to transmit signals, can be configured by the network device or determined by the terminal device, and this application does not limit this.

[0604] If the parameter is configured by the network device, the network device may indicate the fourth information to the terminal device via fourth information, so that the terminal device performs LFM based on the parameter indicated by the fourth information. Optionally, the method further includes: the terminal device receiving the fourth information from the network device, or the network device sending the fourth information to the terminal device, where the fourth information is used to indicate the modulation parameter.

[0605] If the parameter is determined by the terminal device, the terminal device may indicate the parameter to the network device through the fourth information, so that the network device performs LFM demodulation based on the parameter indicated by the fourth information. Optionally, the method further includes: the terminal device sending the fourth information to the network device, or the network device sending the fourth information to the terminal device, where the fourth information is used to indicate the modulation parameter.

[0606] When the modulation mode is LFM, the modulation parameters may include, for example, the bandwidth F of the frequency band used to transmit the signal. In this embodiment, F may refer to the bandwidth of the frequency band used to transmit the first OFDM baseband signal, or the bandwidth of the target frequency band.

[0607] It should be understood that the formula satisfied by the first OFDM baseband signal shown above is only an example given in combination with the formula provided above. Those skilled in the art can make other possible mathematical transformations or equivalent substitutions based on this, and these mathematical transformations or equivalent substitutions should all fall within the scope of protection of this application.

[0608] As mentioned in method 600 above, upconversion is not limited to direct frequency modulation and can also be achieved through I / Q modulation. In this case, the first OFDM baseband signal generated by the terminal device based on the fourth symbol sequence and the first CP sequence is not limited to the form directly obtained by using Formula 4, Formula 4.1, or Formula 5, Formula 5.1. The first OFDM baseband signal can include an I baseband signal and a Q baseband signal.

[0609] Taking CPM as an example, the I-channel baseband signal can be The Q-channel baseband signal can be Alternatively, the I-channel baseband signal can be The Q-channel baseband signal can be The I-channel baseband signal and the Q-channel baseband signal can be mixed by the I-channel mixer and the Q-channel mixer respectively to achieve frequency band shifting and obtain the bandpass signal after superposition. t and as well as t' and The definitions of other parameters can be found in the above descriptions of Formula 4, Formula 4.1, Formula 5, and Formula 5.1, and will not be repeated here.

[0610] In this embodiment, the time domain resource of the first OFDM baseband signal can be an OFDM symbol, that is, the first OFDM baseband signal can be mapped to an OFDM symbol in the time domain. In other words, the above-mentioned second symbol sequence can be transmitted through a single OFDM symbol. In other words, the (N+M)×S time domain samples used to carry the second symbol sequence can be transmitted through a single OFDM symbol, and the transmission duration of each time domain sample is: 1 / [(N+M)×S×Δf], where Δf is the subcarrier spacing and 1 / Δf is the duration of a single OFDM symbol.

[0611] Optionally, the subcarrier spacing is predefined by a protocol, or configured by a network device.

[0612] If the subcarrier spacing is configured by the network device, the method may optionally further include: the terminal device receiving seventh information from the network device, or the network device sending seventh information to the terminal device, where the seventh information is used to indicate the subcarrier spacing. By configuring the subcarrier spacing, the network device can implicitly indicate the duration of an OFDM symbol to the terminal device.

[0613] It should be noted that the subcarrier spacing can also be indicated by existing signaling, for example, in 5G, it can be indicated by a numerology index. In other words, the numerology index can indicate the system bandwidth, the CP length corresponding to the system bandwidth, and the subcarrier spacing.

[0614] In step 1504, the terminal device outputs a passband signal based on the first OFDM baseband signal.

[0615] In step 1505, the terminal device performs power amplification on the bandpass signal to obtain a power-amplified bandpass signal.

[0616] In step 1506, the terminal device transmits the power-amplified bandpass signal, and the network device receives the bandpass signal accordingly.

[0617] In step 1507, the network device obtains a first OFDM baseband signal based on the passband signal.

[0618] It should be understood that the specific process of steps 1504 to 1507 is the same as steps 604 to 607 in the above method 600. Please refer to the relevant description above and no further details will be given.

[0619] In step 1508, the network device obtains a fourth symbol sequence based on the first OFDM baseband signal.

[0620] In step 1509, the network device obtains a third symbol sequence based on the fourth symbol sequence.

[0621] In step 1510, the network device obtains the first symbol sequence from the third symbol sequence.

[0622] Optionally, step 1510 includes:

[0623] The network device determines the value of M;

[0624] The network device determines positions of the M extended symbols in the third symbol sequence;

[0625] The network device obtains the first symbol sequence from the third symbol sequence.

[0626] The specific process of steps 1508 to 1510 is the same as steps 608 to 610 in the above method 600. Please refer to the relevant description above and will not be repeated here.

[0627] In addition, the specific implementation of each step of the network device in different forms of RAN can be found in the detailed description of method 600, which will not be repeated here.

[0628] In one possible implementation, steps 1501 to 1503 are implemented by the baseband chip of the terminal device, steps 1504 to 1505 are implemented by the RF chip of the terminal device, the sending action of step 1506 is implemented by the antenna of the terminal device, the receiving action of step 1506 is implemented by the antenna of the network device, step 1507 is implemented by the RF chip of the network device, and steps 1508 to 1510 are implemented by the baseband chip of the network device. To better understand this embodiment, the following diagrams illustrate the process from the terminal device obtaining the first symbol sequence to transmitting the passband signal, and the process from the network device receiving the passband signal to obtaining the first symbol sequence, in conjunction with several different transmitter structures shown in Figure 4.

[0629] (a), (b) and (c) in FIG18 show the processing procedure of the terminal device.

[0630] As shown in (a) in Figure 18, after obtaining the first symbol sequence to be transmitted, the terminal device first expands the first symbol sequence to determine the third symbol sequence, and then modulates the third symbol sequence to obtain the fourth symbol sequence. As mentioned above, the fourth symbol sequence obtained by modulating the third symbol sequence is a continuous symbol sequence, and a discrete fourth symbol sequence can be obtained after sampling. For the sake of simplicity, the continuous fourth symbol sequence and the discrete fourth symbol sequence are not distinguished in the following text and the accompanying drawings. It can be understood that whether it is a continuous fourth symbol sequence or a discrete fourth symbol sequence, it can be collectively referred to as the fourth symbol sequence. The terminal device can perform a time domain period extension on the fourth symbol sequence to obtain Z p The fourth symbol sequence, and then add the CP sequence, we can get Z p The fourth symbol sequence and the p The first CP sequence before the second symbol sequence. Thereafter, the terminal device can p The fourth symbol sequence and the first CP sequence are used to generate a first OFDM baseband signal. After the baseband processing to obtain the first OFDM baseband signal, the terminal device can directly frequency modulate the carrier based on the first OFDM baseband signal to output a passband signal, then power amplify the passband signal and transmit the amplified passband signal through a transmitting antenna. The power amplification includes nonlinear power amplification or linear power amplification.

[0631] The processing shown in (b) of Figure 18 is similar to that of (a) of Figure 18 , except for the method of obtaining the fourth symbol sequence. After obtaining the first symbol sequence to be transmitted, the terminal device first extends the first symbol sequence to determine the third symbol sequence. It then modulates and samples the N symbols to be transmitted and the M extended symbols in the third symbol sequence, respectively, to obtain N modulation symbols and M modulation symbols. These N modulation symbols and M modulation symbols are concatenated to obtain the fourth symbol sequence. Subsequent operations are the same as those in (a) of Figure 18 and will not be repeated here.

[0632] The process shown in (c) of FIG18 is different from (a) and (b) of FIG18. After the terminal device obtains the first symbol sequence to be transmitted, it first expands the first symbol sequence to determine the third symbol sequence, and then obtains Z after periodic time domain extension. p The terminal device can add K1 symbols at the end of the third symbol sequence to Z p Before the third symbol sequence, the eighth symbol sequence is obtained, and then the eighth symbol sequence is modulated and sampled to obtain Z p The fourth symbol sequence and the first CP sequence can then be based on Z p The second symbol sequence and the first CP sequence are used to generate a first OFDM baseband signal. The subsequent operations are the same as those in FIG18(a) and will not be described in detail.

[0633] It should be understood that the processing procedures shown in (a), (b), and (c) of Figure 18 are applicable to (a) and (c) of Figure 4. The difference between (a) and (c) of Figure 4 lies in the power amplifier. In (a) of Figure 4, the power amplifier is a nonlinear power amplifier, so in the processing procedures shown in (a), (b), and (c) of Figure 18, the linear / nonlinear power amplification can specifically be nonlinear power amplification; in (c) of Figure 4, the power amplifier is a linear power amplifier, so in the processing procedures shown in (a), (b), and (c) of Figure 18, the linear / nonlinear power amplification can specifically be linear power amplification.

[0634] The processing shown in (a), (b), and (c) of Figure 19 is applicable to (b) of Figure 4. The difference between (b) and (a) of Figure 4 lies in the different devices used for upconversion. The specific processing methods for upconversion shown in (a), (b), and (c) of the corresponding Figures 18 are also different from the specific processing methods for upconversion shown in (a), (b), and (c) of Figure 19. The specific processing method for upconversion shown in (a), (b), and (c) of Figure 18 is direct frequency modulation, with the input being the first OFDM baseband signal and the output being a bandpass signal (or frequency-modulated signal). The specific processing method for upconversion shown in (a), (b), and (c) of Figure 19 is I / Q modulation, with the input being the I baseband signal and the Q baseband signal and the output being a bandpass signal. The I baseband signal and the Q baseband signal are derived from the first OFDM baseband signal. The specific generation method can be found in the relevant description of step 1503 above and will not be repeated here. The other operations are the same as those in (a) of Figure 18 and will not be repeated here.

[0635] The processing process of the network device can be found in (a), (b), (c) of Figure 16 in the above method 600 and its related descriptions, which will not be repeated here.

[0636] Based on the above technical solution, by expanding the first symbol sequence to obtain the third symbol sequence, and then modulating the fourth symbol sequence to obtain the fourth symbol sequence, the following conditions can be met at the same time: phase continuity, self-circulation of the first and tail phases, and the end position of the first CP sequence and the starting position of the fourth symbol sequence are also phase continuous. The first OFDM baseband signal generated based on the fourth symbol sequence and the first CP sequence also satisfies phase continuity. Based on this, if the modulation technology used is a modulation technology that can maintain a constant amplitude, a waveform with continuous phase and constant envelope can be obtained. In this way, a solution for combining phase or frequency modulation technology with OFDM technology to obtain a constant envelope waveform can be implemented. Since the constant envelope waveform meets the waveform requirements of direct frequency conversion and nonlinear power amplification, communication equipment can use some more power-saving methods to transmit signals. Therefore, for communication equipment (especially IoT nodes with small size and no large-capacity batteries), the standby life is improved. In addition, in this embodiment, the RE mapping of the terminal device, OFDM baseband signal generation, and the de-RE mapping and channel equalization steps of the network device are all performed in the time domain. That is to say, the signal processing process does not need to be converted to the frequency domain through Fourier transform, and then converted back to the time domain after completing the frequency domain processing, which can greatly reduce the amount of calculation and save power consumption.

[0637] After receiving the passband signal and demodulating it to obtain the third symbol sequence, the network device can derive the first symbol sequence from the third symbol sequence based on the number of extended symbols and their positions within the third symbol sequence, thereby allowing the first symbol sequence to be received. As can be seen, the processing performed by the network device after receiving the passband signal does not require significant changes compared to the current processing, thus achieving better compatibility.

[0638] Based on the foregoing description in conjunction with Figures 6 to 19, it is not difficult to see that, regardless of whether the first CP sequence is pre-generated before the first OFDM baseband signal is generated, the first OFDM baseband signal is generated based on the fourth symbol sequence, wherein the signal body corresponds to the fourth symbol sequence, and the CP corresponds to the K1 modulation symbols at the end of the fourth symbol sequence. Therefore, the two implementations provided in Figures 6 and 15 are two different implementations of generating the first OFDM baseband signal based on the fourth symbol sequence, and the fourth symbol sequence is modulated using a modulation method such as CPM or LFM based on the third symbol sequence obtained by extending the first symbol sequence. Therefore, the two implementations provided in Figures 6 and 15 are two implementations based on the same concept.

[0639] Figure 20 is a simulation diagram provided by an embodiment of the present application. As shown in Figure 20 (a) and (b), a bandpass signal in a complex plane is shown. The approximately circular polygon in the figure is formed by connecting multiple sample points of the bandpass signal. The horizontal axis represents the real part of the sample point, and the vertical axis represents the imaginary part of the sample point. It can be understood that the higher the sampling rate and the more sample points, the closer the approximately circular polygon in the figure is to a circle. If all the sample points fall on a circle, it means that the waveform has a constant envelope.

[0640] The bandpass signal in (a) of Figure 20 is generated by the signal obtained by modulating the first symbol sequence based on CPM. Some sample points of the bandpass signal in the figure fall within the polygon, causing the envelope to jump and cross the zero point, so the envelope is not constant.

[0641] The bandpass signal in (b) of FIG20 is generated by modulating the third symbol sequence based on CPM. All sample points of the bandpass signal in the figure fall within the polygon and can form an approximate circle, so the envelope is constant.

[0642] By comparison, it can be found that by using the method provided in the embodiment of the present application, adding an extended symbol to the first symbol sequence and then performing CPM, the envelope jump can be eliminated, so that the waveform of the bandpass signal has a constant envelope.

[0643] Different numbers of extended symbols, M, can result in different spectral efficiencies and varying degrees of spectral leakage. A large M may result in low spectral efficiency but minimal spectral leakage; a small M may result in high spectral efficiency but significant spectral leakage. Therefore, by constraining the range of M, a compromise between spectral efficiency and spectral leakage can be achieved.

[0644] The following describes the value range of M using two different modulation modes, CPM and LFM.

[0645] Optionally, the modulation mode is CPM, and M may satisfy: 1≤M≤max{U+2, U+V-1} and be an integer.

[0646] V satisfies: h = W / V, and W / V is the simplest fraction, and h is the modulation index of CPM. Among them, W, U and V are all positive integers. For example, if h is 0.5, then it can be obtained that: h = 1 / 2, that is, V = 2; for another example, if h is 1 / 3, because 1 / 3 itself is the simplest fraction, that is, V = 3. U can be used to determine the pulse length of the frequency pulse shaping function g(t) in CPM. For the relationship between the bandpass waveform of CPM and the frequency pulse shaping function, please refer to the description in conjunction with formula 1 in the previous article, and will not be repeated here. It should be noted that the frequency pulse shaping function is a piecewise function. When t < 0 and t > UT, the value of the function is 0; when 0 ≤ t ≤ UT, the value of the function is not 0. In other words, the pulse length of the frequency pulse shaping function is UT, where T is the duration of each symbol. It can be seen that by predefining U, the pulse length of the frequency pulse shaping function can be obtained. U may be predefined by the protocol, or may be a value selected from a plurality of currently disclosed optional values, such as a value selected according to usage requirements, etc. This application does not limit this.

[0647] In this application, to obtain a constant envelope waveform, the terminal device may insert M extended symbols into the first symbol sequence and then perform CPM, so that the ending phase of the fourth symbol sequence obtained by CPM is equal to the initial phase. This process can be viewed as a convolutional coding process: inserting M extended symbols into the first symbol sequence is like inputting an additional M symbols into the convolutional code encoder, causing the register state of the convolutional code to return to the initial state, that is, to the initial phase. [064...

Claims

1. A communication method, characterized in that: include: Acquire a first symbol sequence, where the first symbol sequence includes N symbols to be transmitted, where N is a positive integer; Based on the first symbol sequence, a second symbol sequence is obtained, where symbols in the second symbol sequence are obtained by mapping (N+M) modulation symbols to resource elements RE, where the (N+M) modulation symbols are obtained based on modulating a third symbol sequence, where the third symbol sequence includes the N symbols to be transmitted and M extended symbols in the first symbol sequence, where the M extended symbols make the phases of the (N+M) modulation symbols obtained by the modulation continuous, and the difference between the phase at the starting position and the phase at the ending position is an integer multiple of 2π, where M is an integer greater than or equal to zero; A first orthogonal frequency division multiplexing (OFDM) baseband signal is generated based on the second symbol sequence, wherein the time domain resource of the first OFDM baseband signal is an OFDM symbol.

2. The method according to claim 1, characterized in that The modulation is continuous phase modulation CPM or linear frequency modulation LFM.

3. The method according to claim 1 or 2, characterized in that The method further comprises: The first OFDM baseband signal is sent.

4. The method according to any one of claims 1 to 3, characterized in that The frequency domain resources of the first OFDM baseband signal are (N+M)×S subcarriers, each of the (N+M)×S subcarriers is used to transmit a frequency domain sample point, the (N+M)×S frequency domain samples transmitted by the (N+M)×S subcarriers are obtained by performing Fourier transform on the (N+M)×S time domain samples, and the (N+M)×S time domain samples are obtained by sampling the (N+M) modulation symbols, and S is a positive integer.

5. The method according to claim 4, characterized in that The (N+M)×S subcarriers are continuous subcarriers; or, the (N+M)×S subcarriers are in a comb-teeth shape, and the subcarrier offsets between every two adjacent comb teeth are equal.

6. The method according to claim 5, characterized in that The (N+M)×S subcarriers are in a comb-tooth shape, and the method further includes: Receive or send first information, where the first information is used to indicate the subcarrier offset.

7. The method according to any one of claims 4 to 6, characterized in that The method further comprises: Receive or send second information, where the second information is used to indicate the S.

8. The method according to any one of claims 1 to 7, characterized in that The method further comprises: Third information is received, where the third information is used to indicate a length of a CP of the first OFDM baseband signal.

9. The method according to any one of claims 1 to 8, characterized in that The modulation is CPM, and the method further includes: Receive or send fourth information, where the fourth information is used to indicate one or more of the following: a frequency pulse shaping function, a phase pulse shaping function, a modulation index or an initial phase of the CPM.

10. The method according to any one of claims 1 to 8, characterized in that The modulation is LFM, and the method further comprises: Fourth information is received or sent, where the fourth information is used to indicate a frequency modulation slope of the LFM.

11. The method according to any one of claims 1 to 10, characterized in that The M is a positive integer, and the positions of the M extended symbols in the third symbol sequence are: before the N symbols to be transmitted, or after the N symbols to be transmitted, or continuously or discretely distributed among the N symbols to be transmitted.

12. The method according to any one of claims 1 to 11, characterized in that The method further comprises: receiving or sending fifth information, wherein the fifth information is used to indicate the positions of the M extended symbols in the third symbol sequence, and / or Receive or send sixth information, where the sixth information is used to indicate the M.

13. The method according to any one of claims 1 to 12, characterized in that The time domain resource of the first OFDM baseband signal is adjacent to the time domain resource of the second OFDM baseband signal, and the time domain resource of the second OFDM baseband signal is before the time domain resource of the first OFDM baseband signal, and the time domain resource of the second OFDM baseband signal is one OFDM symbol; The second OFDM baseband signal is generated based on a fifth symbol sequence, and the fifth symbol sequence is modulated based on a sixth symbol sequence, and the sixth symbol sequence includes P symbols to be transmitted and Q extended symbols, Q1 of the Q extended symbols are located in the first (P+Q-K2) symbols in the sixth symbol sequence, and Q2 of the Q extended symbols are located in the last K2 symbols in the sixth symbol sequence, and it is satisfied that the difference between the phase of the end position and the phase of the starting position of the modulation symbol sequence obtained by performing the modulation on the first (P+Q-K2) symbols is an integer multiple of 2π, and the difference between the phase of the end position and the phase of the starting position of the modulation symbol sequence obtained by performing the modulation on the last K2 symbols is also an integer multiple of 2π; wherein P is a positive integer, Q, Q1 and Q2 are integers greater than or equal to 0, K2 represents the length of the cyclic prefix CP of the second OFDM baseband signal, and K2 is an integer greater than 1; and M is an integer greater than 1, M1 of the M extended symbols are among the first (N+M-K1) symbols in the third symbol sequence, and M2 of the M extended symbols are among the last K1 symbols in the third symbol sequence, and satisfy: the modulation is performed on the first (N+M-K1) symbols, and the difference between the phase at the end position and the phase at the starting position of the obtained modulation symbol sequence is an integer multiple of 2π, and the difference between the initial phase of the modulation used to obtain the first OFDM baseband signal and the initial phase of the modulation used to obtain the second OFDM baseband signal is an integer multiple of 2π; wherein, M=M1+M2, M1 and M2 are both integers greater than or equal to 0, K1 represents the length of the CP of the first OFDM baseband signal, and K1 is an integer greater than 1.

14. The method according to any one of claims 1 to 13, characterized in that The method further comprises: A reference signal is sent, wherein the time domain resources of the reference signal are one or more OFDM symbols, and the time domain resources of the reference signal are different from the time domain resources of the first OFDM baseband signal, and the frequency domain resources of the reference signal are the same as the frequency domain resources of the second symbol sequence.

15. A baseband chip, characterized in that: Comprising means for implementing the method of any one of claims 1 to 14, claim 22 or 24 when dependent on any one of claims 1 to 14, or claim 23 or 25.

16. A communication device, characterized in that: include: The baseband chip as claimed in claim 15; The radio frequency chip is used to obtain a bandpass signal based on the first OFDM baseband signal from the baseband chip, and power amplify the bandpass signal to obtain the power-amplified bandpass signal.

17. The communication device according to claim 16, characterized in that The communication device further comprises: An antenna is used to transmit the power-amplified bandpass signal from the radio frequency chip.

18. The communication device according to claim 16 or 17, characterized in that: The radio frequency chip comprises: An up-conversion module, configured to directly frequency modulate a carrier based on the first OFDM baseband signal to obtain the passband signal; A power amplifier is used to power amplify the bandpass signal to obtain the power-amplified bandpass signal.

19. The communication device according to claim 18, characterized in that The up-conversion module includes: a phase-locked loop, a voltage-controlled oscillator or a digitally controlled oscillator.

20. The communication device according to claim 18 or 19, characterized in that: The power amplifier is a nonlinear power amplifier, which is used to perform nonlinear power amplification on the bandpass signal.

21. A communication method, characterized in that: include: Acquire a first orthogonal frequency division multiplexing (OFDM) baseband signal, wherein the time domain resource of the first OFDM baseband signal is an OFDM symbol; Based on the first OFDM baseband signal, obtain a fourth symbol sequence, wherein the fourth symbol sequence includes L modulation symbols, where L is a positive integer; Demodulating the fourth symbol sequence to obtain a third symbol sequence, where the third symbol sequence includes N first symbols and M extended symbols, where L=M+N, N is a positive integer less than or equal to L, and M is an integer greater than or equal to zero; Determining positions of the M and the M extended symbols in the third symbol sequence; The N first symbols are obtained from the third symbol sequence.

22. The method according to any one of claims 1 to 14 or 21, characterized in that The modulation is CPM, and M satisfies: 1≤M≤max{U+2, U+V-1}; wherein, V satisfies: h=W / V, and W / V is the simplest fraction, h is the modulation index of the CPM, U is a predefined value, and W, U and V are positive integers.

23. The method of claim 13, wherein: The modulation is CPM, the M satisfies: 2≤M≤2×max{U+2, U+V-1}, the Q satisfies: 2≤Q≤2×max{U+2, U+V-1}; wherein, the V satisfies: h=W / V, and W / V is the simplest fraction, the h is the modulation index of the CPM, the U is a predefined value, and the W, the U and the V are positive integers.

24. The method according to any one of claims 1 to 14 or 21, characterized in that The modulation is LFM, and M satisfies: 1≤M≤3.

25. The method of claim 13, wherein: The modulation is LFM, the M satisfies: 2≤M≤6; and the Q satisfies: 2≤Q≤6.

26. A communication device, characterized in that: Comprising modules for implementing the method as claimed in any one of claim 21, claim 22 or 24 when dependent on claim 21.

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