Signal transmission method and device

Abstract

The invention discloses a signal transmission method and device. M frequency domain sequences are obtained; performing preset processing on each frequency domain sequence in the M frequency domain sequences, so that the time domain sequence corresponding to each frequency domain sequence shifts to obtain M time domain sequences, the offset delta i of the time domain sequence corresponding to the (i-1) th frequency domain sequence in the M frequency domain sequences in the time domain, the total offset delta i of the time domain sequence corresponding to the ith frequency domain sequence in the time domain and the length Li of the CP of the ith CP-OFDM signal meet a preset relation; cP is added to the M time domain sequences, and M first CP-OFDM signals are formed; and the M first CP-OFDM signals are sent. According to the method and the device, the total offset of the time domain sequences corresponding to the two adjacent frequency domain sequences in the time domain and the length of the CP can meet the preset relation, so that the adjacent CP-OFDM symbols are continuous, the problem of out-of-band interference leakage can be improved, and the reliability of ISAC is improved.

Description

Signal transmission method and device Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a signal transmission method and device. Background Art

[0002] Integrated sensing and communication (ISAC) is widely considered a key application scenario for next-generation wireless communications. Specifically, ISAC means that transmitted wireless signals possess both sensing and communication capabilities. Communication refers to the transmission of information from the transmitter to the receiver. Perception involves sensing the surrounding environment, the speed of objects, and their distance.

[0003] For example, the pilot signal may be designed as a continuous signal (ie, a transmission signal) whose frequency increases linearly with time, namely a linear frequency modulated continuous wave (FMCW), also known as a chirp signal, to implement ISAC, as shown in FIG1 .

[0004] In actual communications, pilot signals can be transmitted using orthogonal frequency division multiplexed (OFDM) symbols. To overcome inter-symbol interference (ISI) caused by multipath delays, a cyclic prefix (CP) can be added to the OFDM symbol to form a CP-OFDM symbol (CP-OFDM symbol for short), as shown in Figure 2.

[0005] However, due to the existence of CP, multiple CP-OFDM symbols are discontinuous, resulting in serious out-of-band interference leakage, which affects the reliability of ISAC.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a signal transmission method and apparatus for solving the problem of how to generate a pilot signal so that CP-OFDM symbols are continuous, thereby ensuring low out-of-band interference leakage and improving the reliability of ISAC.

[0008] In a first aspect, a signal transmission method is provided, comprising obtaining M frequency domain sequences, the M frequency domain sequences corresponding one-to-one to M first cyclic prefix CP-orthogonal frequency division multiplexing (OFDM) signals, where M is a positive integer; m sequences in the M frequency domain sequences are identical, where m is an integer less than or equal to M and greater than or equal to 0; performing a preset process on each frequency domain sequence in the M frequency domain sequences so that a time domain sequence corresponding to each frequency domain sequence is offset, thereby obtaining M time domain sequences; wherein the time domain sequence corresponding to the i-1th frequency domain sequence in the M frequency domain sequences has an offset Δ in the time domain. i-1 , the total offset Δ of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain i , the length L of the CP of the i-th CP-OFDM signal i Satisfy the preset relationship; add a CP to each time domain sequence in the M time domain sequences to form M first CP-OFDM signals; and send the M first CP-OFDM signals.

[0009] In an embodiment of the present application, by performing preset processing on the frequency domain sequence, the total offset of the time domain sequences corresponding to two adjacent frequency domain sequences and the length of the CP can satisfy a preset relationship, thereby achieving continuity between adjacent CP-OFDM symbols, reducing or even avoiding out-of-band interference leakage, and improving the reliability of the ISAC.

[0010] In one possible design, the preset processing includes one or more of the following: frequency domain shift; phase offset; time domain shift.

[0011] This design approach can achieve the offset of the time domain sequence corresponding to each frequency domain sequence through frequency domain processing (such as frequency domain shift and phase offset) or time domain processing (such as time domain shift), and the solution is highly flexible.

[0012] In a possible design, the preset relationship may include: in is an integer, and L is the length of the time domain sequence corresponding to each frequency domain sequence. It can be understood that due to the relationship of cyclic shift, the time domain sequence shift Length, for any Integers are all equivalent. Usually Can be 0, that is, Δ i -Δ i-1 =L i .

[0013] In this design, the difference in the total offset of the time domain sequences corresponding to two adjacent frequency domain sequences is related to the CP corresponding to the frequency domain sequences, so that the CP position is reserved between the time domain sequences corresponding to the two adjacent frequency domain sequences, thereby achieving continuity of two adjacent CP-OFDM symbols.

[0014] In a possible design, a preset process is performed on each of the M frequency-domain sequences, including:

[0015] Performing a cyclic shift on the i-th frequency-domain sequence X i (k) of the M frequency-domain sequences, so that the signal in the i-th frequency-domain sequence X i (k) undergoes a frequency-domain shift, obtaining a second frequency-domain sequence where α i is the frequency-domain shift amount, and N is the number of reference signals;

[0016] Performing a phase shift on the second frequency-domain sequence so that the signal in the i-th frequency-domain sequence undergoes a phase shift, obtaining a third frequency-domain sequence where β i is the phase shift amount, and β i is a real number;

[0017] Mapping the third frequency-domain sequence to N subcarriers through the mapping function f(l), l ∈ Φ, performing an L-point inverse Fourier transform and a time-domain shift, obtaining a first time-domain signal where, T c is the unit time, Δf is the subcarrier width; L i is the CP length of the i-th CP-OFDM signal, and L i is an integer; t s,i is the start time of the i-th CP-OFDM signal, and t e,i is the end time of the i-th CP-OFDM signal; the duration length of the i-th CP-OFDM signal is t e,i - t s,i = (L i + L)T c ; the value range of t is between t s,i and t e,i ; 0 ≤ f(l) < N, and Φ is the set of reference signal subcarriers; W i (l) is the weighting coefficient on the l-th subcarrier; f(l) is the index corresponding to the l-th subcarrier of; O i is the time-domain shift amount, and O i is a real number;

[0018] where, the total offset amount Δ i of the signal in the i-th frequency-domain sequence in the time domain is related to the frequency-domain shift amount α i , the phase shift amount β i , and the time-domain shift amount O i satisfies the following relationship: Among them, γ i is the frequency domain sequence X for the antenna port pair i i The phase shift produced by the signal in (k), N ZC For X i (k) length.

[0019] This design method refines the various steps of the preset processing, namely frequency domain shift, phase shift, and time domain shift, and refines the specific expression of the preset relationship based on frequency domain shift, phase shift, and time domain shift, namely: Improved the reliability of the solution.

[0020] In one possible design, α i =0,O i =0,L i =L CP , L CP is the default value.

[0021] In one possible design, α i =0,β i =γ i ,L i =L CP , O i =-iL CP ;L CP is the default value.

[0022] It can be understood that the above two sets of parameters are only examples and are not limited to the above two implementation methods.

[0023] In one possible design, α i =0,O i =0,L i =L CP , L CP is the preset value. Correspondingly, α0=0, O0=0,

[0024] In one possible design, α i =0,β i =γ i ,L i =L CP ,O i =-(i+1)L CP ;L CP is the preset value. Correspondingly, α0=0, β0=γ0, O0=-L CP .

[0025] Through the above two implementation methods, the initial frequency point of the 0th CP-OFDM signal can be set to the maximum frequency point or the minimum frequency point, which can generate more complete chirp signals within the same number of CP-OFDM cycles, further improving the performance of ISAC.

[0026] In one possible design, β i L β is a positive integer, L β Is a positive integer.

[0027] For example:

[0028] or,

[0029]

[0030] The above design method constrains β i L β It is a positive integer, which can reduce the complexity of the solution implementation.

[0031] In a possible design, the i-th frequency domain sequence X can be generated based on the time domain ZC sequence x(n) or the frequency domain ZC sequence X(k). i (k);

[0032] in, q is the root of the time-domain ZC sequence, 0<|q| <N ZC , and |q| and N ZC Mutually prime; N ZC is the length of the time domain ZC sequence, which is a positive integer; c = N mod 2; p is an integer; n is the index of the sequence x(n);

[0033] in, k is the index of the sequence X(k), q is the root of the frequency-domain ZC sequence shown, 0<|q| <N ZC , and |q| and N ZC Mutually prime; N ZC is the length of the frequency domain ZC sequence, which is a positive integer; c = N mod 2; p is an integer;

[0034] in, or β0L β is a positive integer, L β Is a positive integer.

[0035] Among them, β0L β For example, a positive integer:

[0036] or,

[0037]

[0038] It can be understood that a frequency domain sequence can be obtained by performing Fourier transform on the time domain sequence x(n).

[0039] This design method gives β0L β The specific expression is, by constraining β0L β It is a positive integer, which can reduce the complexity of the solution implementation.

[0040] In one possible design, considering the size of resource block (RB), data scheduling bandwidth, L β It is a multiple of at least one of 2, 3, and 5.

[0041] In one possible design, after sending M first CP-OFDM signals, M second CP-OFDM signals can also be received, where the M second CP-OFDM signals are signals obtained after the M first CP-OFDM signals are transmitted through the channel; the distance and / or speed of the target is determined based on the M first CP-OFDM signals and the M second CP-OFDM signals.

[0042] This design approach can achieve the effect of sensing the distance and / or speed of a target based on the CP-OFDM signal.

[0043] In one possible design, the first CP-OFDM signal is a pilot signal. In other words, the embodiment of the present application can generate a pilot signal by the above method, so that any two adjacent CP-OFDM signals in the pilot signal are continuous.

[0044] This design approach can improve the performance of implementing ISAC based on pilot signals.

[0045] In a second aspect, a signal transmission device is provided, which includes a module or unit or technical means for implementing the method described in the above-mentioned first aspect or any possible design of the first aspect.

[0046] Exemplarily, the apparatus may include:

[0047] A processing module is configured to obtain M frequency domain sequences, where the M frequency domain sequences correspond one-to-one to M first cyclic prefix CP-orthogonal frequency division multiplexing OFDM signals, where M is a positive integer; m sequences in the M frequency domain sequences are identical, where m is an integer less than or equal to M and greater than or equal to 0; perform preset processing on each frequency domain sequence in the M frequency domain sequences so that the time domain sequence corresponding to each frequency domain sequence is offset, thereby obtaining M time domain sequences; wherein the time domain sequence corresponding to the i-1th frequency domain sequence in the M frequency domain sequences has an offset Δ in the time domain. i-1 , the total offset Δ of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain i, the length L of the CP of the i-th CP-OFDM signal i Satisfying a preset relationship; adding a CP to each of the M time domain sequences to form M first CP-OFDM signals;

[0048] The transceiver module is configured to send M first CP-OFDM signals.

[0049] In one possible design, the preset processing includes one or more of the following: frequency domain shift; phase offset; time domain shift.

[0050] In one possible design, the preset relationships include:

[0051] in is an integer, and L is the length of the time domain sequence corresponding to each frequency domain sequence.

[0052] In one possible design, when the processing module performs the preset processing on each of the M frequency domain sequences, it is specifically configured to:

[0053] For the i-th frequency domain sequence X in M ​​frequency domain sequences i (k) Perform cyclic shift so that the i-th frequency domain sequence X i The signal in (k) is shifted in the frequency domain to obtain the second frequency domain sequence where α i is the frequency domain shift amount, N is the number of reference signals;

[0054] For the second frequency domain sequence Perform phase shifting so that the i-th frequency domain sequence The signal in the frequency domain produces a phase shift, and the third frequency domain sequence is obtained. where β i is the phase shift, β i is a real number;

[0055] The third frequency domain sequence The first time domain signal is obtained by mapping the mapping function f(l), l∈Φ to N subcarriers, performing L-point inverse Fourier transform and time domain shift. Among them, T c is the unit time, Δf is the subcarrier width; L i is the CP length of the i-th CP-OFDM signal, L i is an integer; t s,i is the starting time of the i-th CP-OFDM signal, t e,i is the end time of the i-th CP-OFDM signal; the duration of the i-th CP-OFDM signal is t e,i -ts,i =(L i +L)T c ; The value range of t is from t s,i to t e,i ; 0 ≤ f(l) < N, Φ is the set of reference signal subcarriers; W i (l) is the weighting coefficient on the l-th subcarrier; f(l) is the index corresponding to the l-th subcarrier; O i is the time-domain shift amount, O i is a real number;

[0056] Among them, the total offset Δ of the signal in the i-th frequency-domain sequence in the time domain i and the frequency-domain shift amount α i , the phase offset amount β i , and the time-domain shift amount O i satisfy the following relationship: Among them, γ i is the phase offset generated by the antenna port for the signal in the i-th frequency-domain sequence X i (k); N ZC is the length of X i (k).

[0057] In a possible design, α i = 0, O i = 0, L i = L CP , L CP is a preset value.

[0058] In a possible design, α i = 0, β i = γ i , L i = L CP , O i = -iL CP ; L CP is a preset value.

[0059] In a possible design, α i = 0, O i = 0, L i = L CP , L CP is a preset value.

[0060] In a possible design, α i = 0, β i = γ i , L i = L CP , O i=-(i+1)L CP ;L CP is the default value.

[0061] In one possible design, β i L β is a positive integer, L β Is a positive integer.

[0062] In one possible design,

[0063] or,

[0064] In one possible design, the processing module is further configured to:

[0065] Generate the i-th frequency domain sequence X based on the time domain ZC sequence x(n) or the frequency domain ZC sequence X(k) i (k);

[0066] in, q is the root of the time-domain ZC sequence, 0<|q| <N ZC , and |q| and N ZC Mutually prime; N ZC is the length of the time domain ZC sequence, which is a positive integer; c = N mod 2; p is an integer; n is the index of the sequence x(n);

[0067] in, k is the index of the sequence X(k), q is the root of the frequency-domain ZC sequence shown, 0<|q| <N ZC , and |q| and N ZC Mutually prime; N ZC is the length of the frequency domain ZC sequence, which is a positive integer; c = N mod 2; p is an integer;

[0068] in, or β0L β is a positive integer, L β Is a positive integer.

[0069] It can be understood that a frequency domain sequence can be obtained by performing Fourier transform on the time domain sequence x(n).

[0070] In one possible design,

[0071] or,

[0072]

[0073] In one possible design, L β It is a multiple of at least one of 2, 3, and 5.

[0074] In one possible design, the transceiver module is also used to receive M second CP-OFDM signals, where the M second CP-OFDM signals are signals obtained after the M first CP-OFDM signals are transmitted through the channel; the processing module is also used to determine the distance and / or speed of the target based on the M first CP-OFDM signals and the M second CP-OFDM signals.

[0075] In one possible design, the first CP-OFDM signal is a pilot signal.

[0076] In a third aspect, a communication device is provided, comprising a processor and an interface circuit, wherein the interface circuit is electrically coupled to the processor, and the processor executes the method described in the first aspect or any possible design method of the first aspect through a logic circuit or execution code instructions.

[0077] In a fourth aspect, a computer-readable storage medium is provided, in which a computer program or instruction is stored. When the computer program or instruction is executed, the method described in the first aspect or any possible design method of the first aspect is executed.

[0078] In a fifth aspect, a computer program product is provided, comprising instructions, which, when executed on a computer, enables the method described in the first aspect or any optional embodiment of the first aspect to be executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] FIG1 is a schematic diagram of a chirp signal;

[0080] FIG2 is a schematic diagram of multiple chirp signals;

[0081] FIG3 is a schematic diagram of subcarrier mapping;

[0082] FIG4 is a schematic diagram showing discontinuities between OFDM symbols;

[0083] FIG5A, FIG5B, and FIG5C are schematic diagrams of several possible application scenarios of the embodiments of the present application;

[0084] FIG6 is a flow chart of a signal transmission method provided in an embodiment of the present application;

[0085] FIG7A is a schematic diagram showing the continuity between CP-OFDM symbols;

[0086] FIG7B is a schematic diagram showing that the initial frequency of the 0th CP-OFDM signal is the minimum frequency and that the CP-OFDM symbols are continuous;

[0087] FIG8 is a schematic diagram of out-of-band interference leakage;

[0088] FIG9 is a schematic structural diagram of a signal transmission device provided in an embodiment of the present application;

[0089] FIG10 is a schematic structural diagram of another signal transmission device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0090] The embodiments of the present application can be applied to the technical solutions of the embodiments of the present application can be applied to various communication systems, for example: fifth-generation (5G) communication systems, sixth-generation (6G) communication systems or other future evolutionary systems, or various other systems using wireless communication, etc., and the technical solutions of the embodiments of the present application can all be adopted.

[0091] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B may be singular or plural. In the textual description of the present application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formulas of the present application, the character " / " indicates that the previous and next associated objects are in a "division" relationship. "Including at least one of A, B and C" may mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0092] It should be understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of execution of each process should be determined by its function and inherent logic.

[0093] Integrated sensing and communication (ISAC) is widely considered to be a key application scenario for next-generation wireless communication systems, such as the sixth generation (6G) communication systems.

[0094] Radar is a common sensing device. Its operating principle is that the transmitter emits a continuous signal (i.e., the transmitted signal) whose frequency increases linearly with time. This signal is called a frequency modulated continuous wave (FMCW), also known as a chirp signal, as shown in Figure 1. When the transmitted signal reflects off an object, it forms a reflected signal, which is received by the transmitter. Due to delays along the propagation path, there is a frequency difference Δf between the reflected signal and the transmitted signal. This frequency difference Δf is positively correlated with the propagation delay τ:

[0095]

[0096] Where R is the frequency change rate of the continuous frequency modulation signal, which is the ratio of the bandwidth (BW) of the continuous frequency modulation signal to the period T of the continuous frequency modulation signal. d is the distance between the target object (i.e., the object reflecting the signal) and the transmitter (i.e., the radar). c = 3·10 8 m / s is the speed of electromagnetic wave propagation, BW is the bandwidth, and T is the period of frequency change.

[0097] The radar mixes the received reflected signal with the transmitted signal to obtain the frequency difference Δf between the two. Based on Δf, the distance between the object and the transmitter (which is also the receiver of the reflected signal, i.e., the radar) can be calculated.

[0098] Among them, Δf<<BW, that is, the sampling rate of the receiver analog-to-digital converter (ADC) does not need to be designed according to the requirements of the entire signal bandwidth BW, but only needs to be designed according to Δf, which can reduce the sampling rate of the ADC and reduce costs.

[0099] For example: T = 1ms, d = 1km, then:

[0100]

[0101] in, Therefore, FMCW-based linear frequency modulation signals (chirp signals) are often used in perception.

[0102] Furthermore, the radar can also send multiple chirp signals continuously and detect the speed through the phase shift on different chirp signals, as shown in Figure 2.

[0103] The pilot signal (also called preamble signal, preamble, or pilot signal, etc.) is one of the common signals in communications.

[0104] The uplink pilot design can use the ZC sequence. ZC stands for "Zadoff–Chu" sequence, also known as Chu sequence or Frank–Zadoff–Chu (FZC) sequence. Specifically:

[0105]

[0106] Among them, q is the root of the ZC sequence, 0 <q<N ZC , and q and N ZC Coprime, c = N ZC mod 2, p is an integer, N ZC is the length of the ZC sequence (a positive integer).

[0107] A typical ZC sequence is N ZC is a prime number, c = 1, p = 0, that is:

[0108]

[0109] It can be understood that based on the ZC sequence, if -N ZC < q < 0 is allowed, and at the same time -q and N ZC are relatively prime. Then the ZC sequence can also be written as:

[0110] Or,

[0111]

[0112] where 0 < q < N ZC or -N ZC < q < 0, and abs(q) and N ZC are relatively prime, c = N ZC mod 2, p is an integer, and N ZC is the length of the ZC sequence (taking positive integer values). Here, abs(q) represents the function of taking the absolute value of q.

[0113] When using the ZC sequence to design the uplink pilot, the ZC sequence can be generated in the frequency domain:

[0114]

[0115] where N ZC is the largest prime number less than or equal to the number of reference signals N.

[0116] Then, it is extended to N reference signals through cyclic shift, that is:

[0117]

[0118] Then, these N reference signals are inserted onto the corresponding reference signal subcarriers, as shown in Figure 3 for example. Note that Figure 3 takes the transmission bandwidth as N d subcarriers, and the reference signals are sent every other subcarrier as an example, that is:

[0119]

[0120] Of course, Figure 3 is only an example, and the actual situation is not limited to this.

[0121] Then, the time domain signal is obtained through an inverse Fourier transform (such as an inverse fast Fourier transform (IFFT) or an inverse discrete Fourier transform (IDFT)). A cyclic prefix (CP) is added to form a CP-OFDM signal (i.e., a pilot signal) and transmitted through the antenna.

[0122] The pilot signal generated by the above method is approximately a chirp signal, and thus can be used as an FMCW signal to detect objects.

[0123] However, due to the existence of CP, multiple CP-OFDM symbols are discontinuous, resulting in serious out-of-band interference leakage, which affects the reliability of ISAC.

[0124] As we'll understand, the term "discontinuity" between OFDM symbols in this context refers to sudden changes in the signal's amplitude or phase, which can lead to high-frequency components and severe out-of-band interference. As shown in Figure 4, the frequency and phase of two adjacent CP-OFDM symbols are suddenly different, leading to severe out-of-band interference.

[0125] In view of at least the above factors, a technical solution according to an embodiment of the present application is provided to solve the problem of how to generate a pilot signal so that the CP-OFDM symbols are continuous, thereby ensuring low out-of-band interference leakage and improving the reliability of the ISAC.

[0126] It is understandable that the communication signal in the embodiment of the present application includes but is not limited to a pilot signal, and can actually be a communication signal in other forms. For ease of description, the embodiment of the present application takes the communication signal being a pilot signal as an example.

[0127] For example, referring to Figure 5A , embodiments of the present application can be applied to a satellite-terminal communication system, which includes a satellite and a terminal-type network element. The satellite provides communication services to the terminal devices, which include, but are not limited to, smartphones, smartwatches, and tablets. The satellite transmits downlink data to the terminal, and the terminal transmits uplink data to the satellite.

[0128] For example, referring to FIG5B , the embodiments of the present application can be applied to satellite and satellite communication systems. Traditional satellite intersatellite link communication systems can be divided into two major parts: the Acquisition, Tracking and Pointing (APT) subsystem and the communication subsystem. The communication subsystem is responsible for the transmission of intersatellite information and is the main body of the intersatellite communication system; the APT subsystem is responsible for the capture, alignment and tracking between satellites. Among them, the meaning of capture is to determine the incoming wave direction of the incident signal, the meaning of alignment is to adjust the transmission wave to aim at the receiving direction, and the meaning of tracking is to continuously adjust the alignment and capture during the entire communication process.

[0129] For example, referring to FIG5C , embodiments of the present application can be applied to wireless communication systems such as cellular communication or wireless local area network communication. In a cellular communication system, a network device can provide services to multiple terminals, and a terminal can also communicate with multiple network devices. In a wireless local area network communication system, a single access point can provide services to multiple terminals, and a terminal can also communicate with multiple access points.

[0130] Among them, a network device is a device deployed in a wireless access network or a wireless local area network to provide wireless communication functions for terminal devices. Network devices can include various forms of macro base stations, micro base stations (also known as small stations), relay stations, access points, etc. In systems using different wireless access technologies, the names of network devices may be different. The network device can also be a wireless controller in a CRAN (Cloud Radio Access Network) scenario. The network device can also be a base station device in a future 5G network or a network device in a future evolved PLMN network. The network device can also be a wearable device or a vehicle-mounted device. The network device can also be a transmission and reception point (TRP). The network device can also be an access point (AP).

[0131] In addition, the terminals referred to in this article may also be referred to as terminal devices. Terminals may include various handheld devices with wireless communication capabilities, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem. A terminal may be a mobile station (MS), a subscriber unit, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA), a tablet computer, a wireless modem, a handheld device, a laptop computer, a machine type communication (MTC) terminal, etc.

[0132] It should be understood that the above communication systems are only examples. In actual applications, the embodiments of the present application can also be applied to other communication systems.

[0133] Referring to FIG6 , which is a flowchart of a signal transmission method provided in an embodiment of the present application, the method can be applied to any device (such as a satellite, base station, terminal, or access point) in any of the above-mentioned communication systems. The method includes:

[0134] S601. Acquire M frequency domain sequences, where the M frequency domain sequences correspond one-to-one to M first cyclic prefix CP-orthogonal frequency division multiplexing (OFDM) signals, and M is a positive integer.

[0135] Among the M frequency domain sequences, m sequences are identical, and m is an integer less than or equal to M and greater than or equal to 0. In other words, when M is a multiple number, some of the multiple frequency domain sequences may be identical (i.e., some of the frequency domain sequences are different), all of the frequency domain sequences may be identical, or all of the frequency domain sequences may be different.

[0136] In one possible implementation, the i-th frequency domain sequence X can be generated based on the frequency domain ZC sequence X(k). i (k) Frequency domain ZC sequence X(k) For example:

[0137]

[0138] Where k is the index of the sequence X(k), q is the root of the frequency-domain ZC sequence shown, and 0<|q| <N ZC , and q and N ZC Mutually prime; N ZC is the length of the frequency domain ZC sequence, which is a positive integer; c = N mod 2; p is an integer.

[0139] In another possible implementation, the i-th frequency domain sequence X can be generated based on the time domain ZC sequence x(n) i (k), the time domain ZC sequence x(n) is, for example:

[0140]

[0141] Where q is the root of the time-domain ZC sequence, 0<|q| <N ZC , and q and N ZC Mutually prime; N ZC is the length of the time-domain ZC sequence, which is a positive integer; c=N mod 2; p is an integer; and n is the index of the sequence x(n).

[0142] In one possible example, the i-th frequency domain sequence X is generated based on the time domain ZC sequence x(n): i (k) The process may include:

[0143] First, generate the time domain N ZC Extended ZC sequences:

[0144]

[0145] Where n is the index of the x(n) sequence.

[0146] Then, perform a cyclic shift on x(n):

[0147]

[0148] Where n is The index of the sequence, a is an integer.

[0149] Finally, yes Perform Fourier transform to obtain the frequency domain sequence:

[0150]

[0151] Where k is the index of the X(k) sequence.

[0152] It can be understood that the M frequency domain sequences will eventually be modulated into time domain signals and carried on M first CP-OFDM symbols respectively, forming M first CP-OFDM signals to be sent out. Therefore, the M frequency domain sequences correspond one-to-one to the M first CP-OFDM signals, which can also be described as a one-to-one correspondence between the M frequency domain sequences and the M first CP-OFDM symbols.

[0153] S602. Perform a preset process on each of the M frequency-domain sequences, so that the time-domain sequence corresponding to each frequency-domain sequence is shifted, and M time-domain sequences are obtained; where, the offset Δ of the time-domain sequence corresponding to the (i - 1)-th frequency-domain sequence among the M frequency-domain sequences in the time domain i-1 , the total offset Δ of the time-domain sequence corresponding to the i-th frequency-domain sequence in the time domain i , and the length L of the CP of the i-th CP-OFDM signal i satisfy a preset relationship.

[0154] It can be understood that in the embodiments of the present application, the M frequency-domain sequences can be numbered starting from 0. Correspondingly, the value range of i in Δ i is a positive integer from 0 to M - 1. Taking M = 3 as an example, the M frequency-domain sequences successively include: the 0-th frequency-domain sequence, the 1-st frequency-domain sequence, and the 2-nd frequency-domain sequence.

[0155] Alternatively, the M frequency-domain sequences can be numbered starting from 1. Correspondingly, the value range of i in Δ i is a positive integer from 1 to M. Exemplarily, taking M = 3 as an example, the M frequency-domain sequences successively include: the 1-st frequency-domain sequence, the 2-nd frequency-domain sequence, and the 3-rd frequency-domain sequence.

[0156] Of course, in practical applications, the M frequency-domain sequences can also be numbered starting from other values, which is not limited in this application.

[0157] For the convenience of description, in the following, mainly taking the example that the M frequency-domain sequences are numbered starting from 0 for description.

[0158] In the embodiments of the present application, the preset process includes but is not limited to one or more of the following:

[0159] (1) Frequency-domain shift;

[0160] Frequency-domain shift means performing a shift process on the frequency-domain sequence in the frequency domain. Through frequency-domain shift, and then performing an inverse Fourier transform on the frequency-domain sequence after frequency-domain shift, the obtained time-domain sequence will have an offset in the time domain compared to the time-domain sequence obtained by directly performing an inverse Fourier transform on the original frequency-domain sequence. Therefore, time-domain offset can be achieved by frequency-domain shift.

[0161] In a specific implementation, for the i-th frequency-domain sequence X i (k) among the M frequency-domain sequences, circular shift can be performed through circular shift. For example, if N ZC < N, then X(k) is circularly extended to N. If N ZC > N, then X(k) is truncated to N:

[0162]

[0163] in, represents the i-th frequency domain sequence X i (k) performs cyclic shift on the frequency domain sequence, α i is the frequency domain shift amount, N is the number of reference signals, and The length of the sequence is also The number of subcarriers to which it is mapped.

[0164] Frequency domain shift α i The time domain offset caused by Where L is the length (or size or number of points) of the inverse Fourier transform, N ZC For sequence X i (k) length.

[0165] It should be noted that the frequency domain shift α i Can be 0, frequency domain shift amount α i When it is 0, it is equivalent to not performing frequency domain shift on the frequency domain sequence.

[0166] (2) Phase offset;

[0167] Phase shifting involves performing a phase shift on a frequency domain sequence. By performing a phase shift and then performing an inverse Fourier transform on the phase-shifted frequency domain sequence, the resulting time domain sequence will be offset in the time domain compared to the time domain sequence obtained by directly performing an inverse Fourier transform on the original frequency domain sequence. Therefore, phase shifting can also achieve time domain offset.

[0168] For example, for the i-th frequency domain sequence X in M ​​frequency domain sequences i (k) Perform phase shift, which can be expressed as:

[0169]

[0170] Among them, β i is the phase shift, β i is a real number.

[0171] Phase offset β i The time domain offset caused by this can be expressed as Lβ i , where L is the length (or size or number of points) of the inverse Fourier transform, which is also the length of the time domain sequence after the inverse Fourier transform.

[0172] In practical applications, phase shift can also be performed on the frequency domain sequence after frequency domain shift, for example:

[0173]

[0174] It should be noted that the phase shift β i Can be 0, phase offset βi When it is 0, it is equivalent to not performing phase shift on the frequency domain sequence.

[0175] In one possible case, when there are multiple antenna ports, in order to ensure that the signals sent by each antenna port are orthogonal to each other (in short, the antenna ports are orthogonal to each other), it is necessary to perform a phase shift on the i-th frequency domain sequence. For the sake of convenience, the phase shift caused by the orthogonality factor between the antenna ports is described as the phase shift of the antenna port to the i-th frequency domain sequence X i The phase shift produced by the signal in (k) is expressed as γ i Indicates that γ i is a real number. When there are multiple antenna ports, different antenna ports can correspond to different γ i value, thereby ensuring that the signals sent by each port are orthogonal. Assuming that the signal in the i-th frequency domain sequence is sent by antenna port v, then when v takes different values, γ i It can be different.

[0176] Understandably, i Can contain γ i γ i When it is not 0, we can first consider β i =γ i In the case of , whether the preset relationship is satisfied, if it is satisfied, no additional phase offset is required, if not, an additional phase offset can be added, that is, β i >γ i , such as β i =γ i +w i , w i That is, an additional phase offset is provided so that the preset relationship can be satisfied.

[0177] In some cases, γ i The value can be 0. For example, the number of antenna ports is 1; or, for example, the phase offset caused by the orthogonality between antenna ports is not considered; or, for example, the phase offset generated by antenna port v that transmits the signal in the i-th frequency domain sequence is exactly 0, while the phase offsets generated by other antenna ports are not 0, which also satisfies the mutual orthogonality between antenna ports, etc.

[0178] (3) Time domain shift.

[0179] It can be understood that time domain shift refers to the operation of shifting the time domain sequence in the time domain after the frequency domain sequence is obtained by inverse Fourier transform. This operation can directly realize time domain offset.

[0180] Exemplarily, first, a frequency-domain sequence (it can be understood that the frequency-domain sequence here can be the original frequency-domain sequence X(k), or a frequency-domain sequence after frequency-domain shift and / or phase shift, without limitation) is mapped to N subcarriers through a mapping function f(l), l ∈ Φ, and an L-point inverse Fourier transform and a time-domain shift are performed to obtain a time-domain signal where, T c is the unit time, Δf is the subcarrier width; L i is the CP length of the i-th CP-OFDM signal, L i is an integer; t s,i is the start time of the i-th CP-OFDM signal, t e,i is the end time of the i-th CP-OFDM signal; the duration length of the i-th CP-OFDM signal is t e,i - t s,i = (L i + L)T c ; the value range of t is [t s,i , t e,i ; 0 ≤ f(l) < N, Φ is the set of reference signal subcarriers; W i (l) is the weighting coefficient on the l-th subcarrier; f(l) is the index corresponding to the l-th subcarrier of; O i is the time-domain shift amount, O i is a real number.

[0181] It should be noted that the time-domain shift amount O i can be 0. When the time-domain shift amount O i is 0, it is equivalent to not performing a time-domain shift on the time-domain sequence.

[0182] It can be understood that the above three operations can be implemented separately in an embodiment or in combination with each other in an embodiment.

[0183] As an example, when the above three processing methods are implemented simultaneously, the processing flow may include:

[0184] Perform a cyclic shift on the i-th frequency-domain sequence X i (k) among the M frequency-domain sequences, so that the signals in the i-th frequency-domain sequence X i (k) generate a frequency-domain shift to obtain a second frequency-domain sequence where α i is the frequency-domain shift amount, N is the number of reference signals, and it is also the length of the second frequency-domain sequence;

[0185] Perform a phase shift on the second frequency-domain sequence so that the i-th frequency-domain sequence Xi Generate a phase shift in the signal in (k) to obtain a third frequency-domain sequence where β i is the phase shift amount, and β i is a real number;

[0186] Map the third frequency-domain sequence onto N subcarriers through the mapping function f(l), l ∈ Φ, perform an L-point inverse Fourier transform and a time-domain shift to obtain a first time-domain signal where T c is the unit time, Δf is the subcarrier width; L i is the CP length of the i-th CP-OFDM signal, and L i is an integer; t s,i is the start time of the i-th CP-OFDM signal, and t e,i is the end time of the i-th CP-OFDM signal; the duration length of the i-th CP-OFDM signal is t e,i -t s,i =(L i +L)T c ; the value range of t is [t s,i , t e,i ; 0 ≤ f(l) < N, and Φ is the set of reference signal subcarriers; W i (l) is the weighting coefficient on the l-th subcarrier; f(l) is the index corresponding to the l-th subcarrier; O i is the time-domain shift amount, and O i is a real number.

[0187] Among them, the first time-domain signal can also be identified by a digital discrete time-domain signal, such as:

[0188]

[0189] n ∈ {0,..., L - 1} is an integer, where f(l) is the index corresponding to the l-th subcarrier sequence. Φ is the set of reference signal subcarriers, and W i (l) is the weighting coefficient on the l-th subcarrier.

[0190] In a possible design, the value of the reference signal subcarrier set Φ can be configured by a network device, or can be related to the user terminal identifier (ID).

[0191] In a possible example, f(l) = l-l0, Φ = {l0,…,l0+N-1}, where l0 is an integer. When represented by an analog continuous time domain signal, l0 ≥ 0, which is conducive to expressing the subcarrier index. When represented by a digital discrete time domain signal. Where v is an arbitrary integer, representing the index of the antenna port. In this case, l0 can be a negative integer, 0, or a positive integer. Optionally, for the convenience of digital signal processing, L can be constrained to be an even number, and the sequence Continuously mapped to subcarriers or Therefore, we can further constrain or and, or

[0192] In a possible design, the preset relationship may include:

[0193]

[0194] in is an integer, i is a positive integer less than M, and L is the length of the time domain sequence corresponding to each frequency domain sequence (the length of the time domain sequence corresponding to each frequency domain sequence is the same). In other words, the time domain offset Δ of the time domain sequence corresponding to the i-1th frequency domain sequence in the time domain is i-1 , the total offset Δ of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain i The difference is

[0195] It is understandable that due to the relationship between cyclic shift, the time domain sequence shift Length, for any Integers are all equivalent. In general, It can be 0, that is, the preset relationship may include: Δ i -Δ i-1 =L i .

[0196] In one possible design, the total offset of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain can be expressed as:

[0197]

[0198] The total offset of the time domain sequence corresponding to the i-1th frequency domain sequence in the time domain can be expressed as:

[0199]

[0200] Correspondingly, formula (1) can also be expressed as:

[0201]

[0202] Among them, γ i is the frequency domain sequence X for the antenna port pair i i The phase shift produced by the signal in (k), γ i is a real number.

[0203] Optional, Where m and m0 are integers. Optionally, m∈[0,m0-1], where m0 is an integer multiple of 6 or 8, such as 6, 8, or 12. In a specific implementation, the values ​​of m and m0 can be configured by the network device and can be related to one or more of the following: the index v of the antenna port, the total number N of antenna ports, v , symbol index i related, user terminal identification (ID), etc.

[0204] It can be understood that in practical applications, the above formulas (1) and (2) may have other variations.

[0205] For example, by shifting the terms in the above formula (2), it can be transformed into:

[0206]

[0207] For example, based on The above formula (2) can also be equivalently expressed as:

[0208]

[0209] It can be understood that the above formulas (2), (3), (4), etc. are just a few possible examples. In actual applications, formula (1) can also have other variations, which are not listed one by one in this application.

[0210] In one possible design, O0=0 (indicating no time domain shift). In this case, O i =0, Optional, α i = 0. Optional, p = 0. Optional, Optional, L i =L CP , where L CP is the preset value. When i takes different values, L i All L CP .

[0211] This design is achieved by setting O i is 0, then determine the phase offset β i The values ​​of other parameters such as Δi-1 , Δ i , L i The preset relationship can be satisfied, thereby achieving continuity between CP-OFDM symbols, which can reduce the complexity of implementation.

[0212] In one possible design, β i =γ i (Indicates that the phase shift processing performed on the frequency domain sequence only has the phase offset generated by the antenna port itself). In this case, β i =γ i ,O i =-iL CP γ i ; optional, α i = 0. Optional, Optional, p = 0. Optional, L i =L CP , where L CP is the preset value. When i takes different values, L i All L CP .

[0213] This design is achieved by setting β i =γ i , then determine the time domain shift O i , frequency domain shift α i The values ​​of other parameters such as Δ i-1 , Δ i , L i The preset relationship can be satisfied, thereby achieving continuity between CP-OFDM symbols, which can reduce the complexity of implementation.

[0214] Of course, the above two design methods are only examples, and there may be other parameter design methods.

[0215] Understandably, Or the value of β0,O0 determines the initial frequency of the 0th CP-OFDM signal, so it can be constrained Or the value of β0,O0 is used to constrain the initial frequency of the 0th CP-OFDM signal.

[0216] In a possible design, in order to further reduce the complexity of implementation, β can be constrained i L β is a positive integer, L β Is a positive integer.

[0217] For example:

[0218] or,

[0219]

[0220] in, Indicates rounding up. Indicates rounding down.

[0221] It can be understood that the above formula (2) can be equivalently transformed into formula (4), where β i L β A positive integer can also be replaced by Is a positive integer.

[0222] In one possible design, the initial frequency of the 0th CP-OFDM signal can be constrained to be the maximum frequency or the minimum frequency.

[0223] For example, α i =0,p=0,O i =0,L i =L CP , L CP is the preset value. Correspondingly, α0=0, O0=0,

[0224] For example, α i =0,p=0,β i =γ i ,L i =L CP , O i =-(i+1)L CP ;L CP is the preset value. Correspondingly, α0=0, β0=γ0, O0=-L CP .

[0225] By designing the initial frequency of the 0th CP-OFDM signal to be the maximum frequency or the minimum frequency, more complete chirp signals can be generated within the same number of CP-OFDM cycles, further improving the performance of ISAC.

[0226] In one possible design, according to the above,

[0227] In one possible design, β0L β is a positive integer, L β Is a positive integer.

[0228] β0L β is a positive integer, for example:

[0229] or,

[0230]

[0231] This design approach constrains β0L β A positive integer can further reduce the complexity of the implementation.

[0232] Optionally, according to the size of the resource block (RB) (1 RB = 12 resource elements (RE), 12 is an integer multiple of 2 or 3), the data scheduling bandwidth (if it is a single carrier waveform, the data scheduling bandwidth is x RE, where x is an integer multiple of 2, 3, or 5), L in the embodiment of the present application β The value of L can be a multiple of at least one of 2, 3, and 5. Of course, 2, 3, and 5 are just examples, and this application does not limit L β Possibility of other values.

[0233] S603: Add a CP to each of the M time domain sequences to form M first CP-OFDM signals.

[0234] For example, through the above-mentioned processing of S602, the time domain sequence corresponding to the i-1th frequency domain sequence has an offset in the time domain of Δ i-1 , the total offset of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain is Δ i The difference between the two is A space of length 1 is reserved between the time domain sequence corresponding to the i-1th frequency domain sequence and the time domain sequence corresponding to the i-th frequency domain sequence. Time domain position, by adding L to the reserved time domain position i The CP of length can form the i-th CP-OFDM signal.

[0235] S604: Send M first CP-OFDM signals.

[0236] By sending the M first CP-OFDM signals based on the above process, the frequency conversion between the M first CP-OFDM signals can be continuous, that is, the CP-OFDM symbols corresponding to the M first CP-OFDM signals are continuous.

[0237] For example, see FIG7A , by adjusting β i ,O i A schematic diagram of achieving continuity between CP-OFDM symbols is provided. There is no sudden change in frequency or phase between adjacent CP-OFDM symbols, thus preventing out-of-band interference.

[0238] For example, referring to FIG. 7B , by adjusting Or β0,O0 makes the initial frequency of the 0th CP-OFDM signal the minimum frequency. Compared with FIG7A , more complete chirp signals can be generated within the same number of CP-OFDM cycles.

[0239] The above scheme, by performing preset processing on the frequency domain sequence (such as one or more processing of frequency domain shift, phase offset or time domain shift, etc.), can make the total offset of the time domain sequences corresponding to two adjacent frequency domain sequences in the time domain and the length of the CP meet the preset relationship, thereby achieving continuity between adjacent CP-OFDM symbols, reducing or even avoiding out-of-band interference leakage, and improving the reliability of ISAC.

[0240] In order to better illustrate the technical effect of the above solution, here is a set of experimental data:

[0241] q=3,N ZC =N=256,L=2048,L i =L CP =256,γ i =0;

[0242] O i =0,

[0243] β i =0, O i = -i·256;

[0244] I understand. The value of does not affect out-of-band leakage.

[0245] See Figure 8, which is a comparison diagram of the CP-OFDM signal generated using the above parameters based on the embodiment method of the present application and the original CP-OFDM signal (as shown in Figure 4). It can be seen from Figure 8 that the CP-OFDM signal generated using the solution of the present application effectively reduces out-of-band interference leakage.

[0246] In one possible design, after transmitting M first CP-OFDM signals, M second CP-OFDM signals may be received. These M second CP-OFDM signals are signals obtained by transmitting the M first CP-OFDM signals through a channel. The target's distance and / or speed are then determined based on the M first CP-OFDM signals and the M second CP-OFDM signals. This allows the target's distance and / or speed to be sensed based on the CP-OFDM signals.

[0247] In one possible design, the first CP-OFDM signal is a pilot signal, that is, the pilot signal can be generated using the above method so that any two adjacent CP-OFDM signals in the pilot signal are continuous. In this way, the performance of implementing ISAC based on the pilot signal can be improved.

[0248] Based on the same technical concept, an embodiment of the present application provides a communication device 900, which can be, for example, a satellite, a base station, a terminal, or an access point, or a chip inside a satellite, a base station, a terminal, or an access point. The device 900 includes modules, units, or means corresponding to the steps of the method in the embodiment shown in FIG. 6 above. The functions, units, or means can be implemented by software or hardware, or the corresponding software implementation can be executed by hardware.

[0249] Exemplarily, referring to FIG. 9 , an apparatus 900 may include a processing module 901 and a transceiver module 902 .

[0250] The processing module 901 is configured to obtain M frequency domain sequences, where the M frequency domain sequences correspond one-to-one to M first cyclic prefix CP-orthogonal frequency division multiplexing OFDM signals, where M is a positive integer; m sequences in the M frequency domain sequences are identical, where m is an integer less than or equal to M and greater than or equal to 0; perform preset processing on each frequency domain sequence in the M frequency domain sequences so that the time domain sequence corresponding to each frequency domain sequence is offset, thereby obtaining M time domain sequences; wherein the time domain offset Δ of the time domain sequence corresponding to the i-1th frequency domain sequence in the M frequency domain sequences is i-1 , the total offset Δ of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain i , the length L of the CP of the i-th CP-OFDM signal i Satisfying a preset relationship; adding a CP to each of the M time domain sequences to form M first CP-OFDM signals;

[0251] The transceiver module 902 is configured to send M first CP-OFDM signals.

[0252] It should be understood that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0253] Based on the same technical concept, referring to FIG10 , an embodiment of the present application further provides a communication device 1000, including:

[0254] At least one processor 1001; and a communication interface 1003 communicatively connected to the at least one processor 1001; the at least one processor 1001 executes instructions stored in the memory 1002, so that the device executes the method steps performed by the network device in the embodiment shown in Figure 6 through the communication interface 1003.

[0255] Optionally, the memory 1002 is located outside the device 1000 .

[0256] Optionally, the apparatus 1000 includes the memory 1002, which is connected to the at least one processor 1001 and stores instructions executable by the at least one processor 1001. FIG10 uses dashed lines to indicate that the memory 1002 is optional for the apparatus 1000.

[0257] The processor 1001 and the memory 1002 may be coupled via an interface circuit or may be integrated together, which is not limited here.

[0258] The specific connection medium between the processor 1001, memory 1002, and communication interface 1003 is not limited in the embodiments of the present application. In Figure 10, the processor 1001, memory 1002, and communication interface 1003 are connected via a bus 1004. The bus is represented by a bold line in Figure 10. The connection methods between other components are only for schematic illustration and are not limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one bold line is used in Figure 10, but this does not mean that there is only one bus or one type of bus.

[0259] The specific connection medium between the processor 1001, memory 1002, and communication interface 1003 is not limited in the embodiments of the present application. In Figure 10, the processor 1001, memory 1002, and communication interface 1003 are connected via a bus 1004. The bus is represented by a bold line in Figure 10. The connection methods between other components are only for schematic illustration and are not limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one bold line is used in Figure 10, but this does not mean that there is only one bus or one type of bus.

[0260] It should be understood that the processors mentioned in the embodiments of the present application can be implemented by hardware or software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented by software, the processor can be a general-purpose processor that is implemented by reading software code stored in a memory.

[0261] Exemplarily, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0262] It should be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM).

[0263] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0264] It should be noted that the memory described herein is intended to include, but not be limited to, these and any other suitable types of memory.

[0265] Based on the same technical concept, an embodiment of the present application further provides a computer-readable storage medium, including a program or instruction. When the program or instruction runs on a computer, the method shown in FIG. 6 is executed.

[0266] Based on the same technical concept, an embodiment of the present application further provides a computer program product, including instructions, which, when executed on a computer, enables the method shown in FIG6 to be executed.

[0267] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0268] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0269] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0270] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0271] Obviously, those skilled in the art may make various modifications and variations to this application without departing from the scope of protection of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A signal transmission method, characterized in that: include: Acquire M frequency domain sequences, where the M frequency domain sequences correspond one-to-one to M first cyclic prefix CP-orthogonal frequency division multiplexing (OFDM) signals, and M is a positive integer; m sequences of the M frequency domain sequences are the same, where m is an integer less than or equal to M and greater than or equal to 0; Perform a preset process on each of the M frequency domain sequences so that the time domain sequence corresponding to each frequency domain sequence is offset, thereby obtaining M time domain sequences; wherein the time domain sequence corresponding to the i-1th frequency domain sequence in the M frequency domain sequences has an offset Δ in the time domain i-1 , the total offset Δ of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain i , the length L of the CP of the i-th CP-OFDM signal i Satisfy the preset relationship; Adding a CP to each of the M time domain sequences to form the M first CP-OFDM signals; The M first CP-OFDM signals are sent.

2. The method according to claim 1, wherein The preset processing includes one or more of the following: Frequency domain shift; Phase offset; Time domain shift.

3. The method according to claim 1, wherein The preset relationship includes: wherein is an integer, and L is the length of the time domain sequence corresponding to each frequency domain sequence.

4. The method according to any one of claims 1 to 3, wherein Performing a preset process on each of the M frequency domain sequences includes: For the i-th frequency domain sequence X in the M frequency domain sequences i (k) Perform cyclic shift so that the i-th frequency domain sequence X i The signal in (k) is shifted in the frequency domain to obtain the second frequency domain sequence wherein the α i is the frequency domain shift amount, and N is the number of reference signals; For the second frequency domain sequence Perform phase shifting so that the i-th frequency domain sequence The signal in the frequency domain produces a phase shift, and the third frequency domain sequence is obtained. wherein the β i is the phase offset, the β i is a real number; the third frequency domain sequence The first time domain signal is obtained by mapping the mapping function f(l), l∈Φ to N subcarriers, performing L-point inverse Fourier transform and time domain shift. Among them, the T c is the unit time, where Δf is the subcarrier width; L i is the CP length of the i-th CP-OFDM signal, and L i is an integer; t s,i is the start time of the i-th CP-OFDM signal, and t e,i is the end time of the i-th CP-OFDM signal; the duration of the i-th CP-OFDM signal is t e,i -t s,i =(L i +L)T c ; the value range of t is between t s,i and t e,i ; 0 ≤ f(l) < N, where Φ is the reference signal subcarrier set; W i (l) is the weighting coefficient on the l-th subcarrier; f(l) is the corresponding The index of i is the time domain shift amount, the O i is a real number; The total offset Δ of the signal in the i-th frequency domain sequence in the time domain is i and the frequency domain shift α i , phase shift β i , time domain shift O i The following relationship is satisfied: Among them, the γ i is the frequency domain sequence X of the antenna port pair i i (k) The phase shift of the signal generated, the N ZC For X i (k) length.

5. The method according to claim 4, wherein α i =0,O i =0,L i =L CP , The L CP is the default value.

6. The method according to claim 4, wherein α i =0,β i =γ i ,L i =L CP , O i =-iL CP ; the L CP is the default value.

7. The method according to claim 4, wherein α i =0,O i =0,L i =L CP , The L CP is the default value.

8. The method according to claim 4, wherein α i =0,β i =γ i ,L i =L CP , O i =-(i+1)L CP ; the L CP is the default value.

9. The method according to any one of claims 4 to 8, wherein: β i L β is a positive integer, L β is a positive integer; or, 10. The method according to any one of claims 4 to 9, wherein: The method further comprises: The i-th frequency domain sequence X is generated based on the time domain ZC sequence x(n) or the frequency domain ZC sequence X(k) i (k); in, The q is the root of the time domain ZC sequence, 0<|q| <N ZC , and the |q| and the N ZC mutually prime; the N ZC is the length of the time domain ZC sequence, which is a positive integer; c=N mod 2; p is an integer; n is the index of the sequence x(n); in, The k is the index of the sequence X(k), the q is the root of the frequency domain ZC sequence, 0<|q| <N ZC , and the |q| and the N ZC mutually prime; the N ZC is the length of the frequency domain ZC sequence, which is a positive integer; c=N mod 2; p is an integer; in, Or the β0L β is a positive integer, the L β Is a positive integer.

11. The method according to claim 10, wherein or, 12. The method according to any one of claims 9 to 11, wherein: The L β It is a multiple of at least one of 2, 3, and 5.

13. The method according to any one of claims 1 to 12, wherein: The method further comprises: receiving M second CP-OFDM signals, where the M second CP-OFDM signals are signals obtained after the M first CP-OFDM signals are transmitted through a channel; The distance and / or speed of the target is determined according to the M first CP-OFDM signals and the M second CP-OFDM signals.

14. The method according to any one of claims 1 to 13, wherein: The first CP-OFDM signal is a pilot signal.

15. A signal transmission device, characterized in that: include: A processing module is configured to obtain M frequency domain sequences, wherein the M frequency domain sequences correspond one-to-one to M first cyclic prefix CP-orthogonal frequency division multiplexing OFDM signals, where M is a positive integer; m sequences in the M frequency domain sequences are the same, where m is an integer less than or equal to M and greater than or equal to 0; perform preset processing on each frequency domain sequence in the M frequency domain sequences so that the time domain sequence corresponding to each frequency domain sequence is offset, thereby obtaining M time domain sequences; wherein the time domain sequence corresponding to the i-1th frequency domain sequence in the M frequency domain sequences has an offset Δ in the time domain i-1 , the total offset Δ of the time domain sequence corresponding to the i-th frequency domain sequence in the time domain i , the length L of the CP of the i-th CP-OFDM signal i Satisfying a preset relationship; adding a CP to each of the M time domain sequences to form the M first CP-OFDM signals; A transceiver module is configured to send the M first CP-OFDM signals.

16. The device according to claim 15, characterized in that The preset processing includes one or more of the following: Frequency domain shift; Phase offset; Time domain shift.

17. The device according to claim 15, wherein The preset relationship includes: wherein is an integer, and L is the length of the time domain sequence corresponding to each frequency domain sequence.

18. The device according to any one of claims 15 to 17, characterized in that When the processing module performs the preset processing on each of the M frequency domain sequences, the processing module is specifically configured to: For the i-th frequency domain sequence X in the M frequency domain sequences i (k) Perform cyclic shift so that the i-th frequency domain sequence X i The signal in (k) is shifted in the frequency domain to obtain the second frequency domain sequence wherein the α i is the frequency domain shift amount, and N is the number of reference signals; For the second frequency domain sequence Perform phase shifting so that the i-th frequency domain sequence The signal in the frequency domain produces a phase shift, and the third frequency domain sequence is obtained. wherein the β i is the phase offset, the β i is a real number; the third frequency domain sequence The first time domain signal is obtained by mapping the mapping function f(l), l∈Φ to N subcarriers, performing L-point inverse Fourier transform and time domain shift. Among them, the T c is the unit time, The Δf is the sub - carrier width; the L i is the CP length of the i - th CP - OFDM signal, and the L i is an integer; the t s,i is the start time of the i - th CP - OFDM signal, and the t e,i is the end time of the i - th CP - OFDM signal; the duration length of the i - th CP - OFDM signal is t e,i -t s,i =(L i +L)T c ; the value range of t is between t s,i and t ei ; 0 ≤ f(l)<N, where Φ is the reference signal sub - carrier set; the W i (l) is the weighting coefficient on the l - th sub - carrier; the f(l) is the corresponding The index of i is the time domain shift amount, the O i is a real number; The total offset Δ of the signal in the i-th frequency domain sequence in the time domain is i and the frequency domain shift α i , phase shift β i , time domain shift O i The following relationship is satisfied: Among them, the γ i is the frequency domain sequence X of the antenna port pair i i (k) The phase shift of the signal generated, the N ZC For X i (k) length.

19. The device according to claim 18, wherein α i =0,O i =0,L i =L CP , The L CP is the default value.

20. The device according to claim 18, wherein α i =0,β i =γ i ,L i =L CP , O i =-iL CP ; the L CP is the default value.

21. The device according to claim 18, wherein α i =0,O i =0,L i =L CP , The L CP is the default value.

22. The device according to claim 18, wherein α i =0,β i =γ i ,L i =L CP , O i =-(i+1)L CP ; the L CP is the default value.

23. The device according to any one of claims 18 to 22, characterized in that β i L β is a positive integer, L β is a positive integer; or, 24. The device according to any one of claims 18 to 23, characterized in that The processing module is further configured to: The i-th frequency domain sequence X is generated based on the time domain ZC sequence x(n) or the frequency domain ZC sequence X(k) i (k); in, The q is the root of the time domain ZC sequence, 0<|q| <N ZC , and the |q| and the N ZC mutually prime; the N ZC is the length of the time domain ZC sequence, which is a positive integer; c=N mod 2; p is an integer; n is the index of the sequence x(n); in, The k is the index of the sequence X(k), the q is the root of the frequency domain ZC sequence, 0<|q| <N ZC , and the |q| and the N ZC mutually prime; the N ZC is the length of the frequency domain ZC sequence, which is a positive integer; c=N mod 2; p is an integer; in, Or the β0L β is a positive integer, the L β Is a positive integer.

25. The device according to claim 24, characterized in that or, 26. The device according to any one of claims 23 to 25, characterized in that The L β It is a multiple of at least one of 2, 3, and 5.

27. The device according to any one of claims 15 to 26, characterized in that The transceiver module is further configured to: receive M second CP-OFDM signals, where the M second CP-OFDM signals are signals obtained after the M first CP-OFDM signals are transmitted through a channel; The processing module is further configured to determine a distance and / or speed of a target according to the M first CP-OFDM signals and the M second CP-OFDM signals.

28. The device according to any one of claims 15 to 27, characterized in that The first CP-OFDM signal is a pilot signal.

29. A communication device, characterized in that: The method comprises a processor and an interface circuit, wherein the interface circuit is electrically coupled to the processor, and the processor causes the method according to any one of claims 1 to 14 to be executed through a logic circuit or by executing a code instruction.

30. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instructions, and when the computer program or instructions are executed, the method according to any one of claims 1 to 14 is executed.

Images