Signal modulation method and related apparatus

Abstract

Provided in the present application are a signal modulation method and a related apparatus. The method comprises: acquiring a first symbol sequence, and performing single-carrier modulation on the first symbol sequence, wherein the phase difference between two adjacent symbols in the first symbol sequence is 90°, the single-carrier modulation comprises first scaling factor-based spectrum adjustment and frequency-domain spectrum shaping (FDSS), and the spectrum adjustment comprises spectrum compression; and determining a signal generated after the first symbol sequence is subjected to the single-carrier modulation. The method performs single-carrier modulation on first symbol sequences having a phase difference of 90° between two adjacent symbols, and provides a single-carrier modulation solution for frequency spectrum compression in frequency domains, thus improving the spectrum efficiency and generating single-carrier signals with low PAPR.

Description

Signal modulation method and related device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 13, 2023, with application number 202311717738.5, and invention name “Signal Modulation Method and Related Devices”, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] Fifth-generation (5G) communication systems use orthogonal frequency division multiplexing (OFDM) modulation for downlink signals and discrete Fourier transform spreading (DFT-s-OFDM) modulation for uplink signals. DFT-s-OFDM modulation performs an additional discrete Fourier transform (DFT) before OFDM modulation. This operation gives the DFT-s-OFDM signal the characteristics of a single-carrier modulation signal, resulting in a peak-to-average power ratio (PAPR) far lower than that of multi-carrier modulation signals like OFDM.

[0004] Single-carrier modulation involves shaping and filtering the modulated input symbol sequence in the time domain. Without loss of transmission performance, the minimum filter bandwidth can be equal to the symbol sequence bandwidth (i.e., the width of the frequency domain signal spectrum corresponding to the symbol sequence). The filter width is equal to the transmission bandwidth or scheduling bandwidth. In practical applications, the filter bandwidth is generally greater than the bandwidth of the modulated input symbol sequence. While this design reduces spectral efficiency, it also offers many benefits, one of which is reduced PAPR for single-carrier signals.

[0005] Single-carrier modulation can also be implemented equivalently in the frequency domain. The frequency domain implementation is similar to DFT-s-OFDM modulation. First, the time-domain modulation input symbol sequence is converted into a frequency-domain signal through DFT. Time-domain shaping filtering in single-carrier modulation is equivalent to windowing the frequency-domain signal in the frequency domain, also known as frequency-domain spectrum shaping (FDSS). If the filter bandwidth is larger than the bandwidth of the modulated input symbol sequence, the frequency-domain signal must first be spectrally expanded and then windowed. The bandwidth after expansion matches the bandwidth of the filter.

[0006] However, for some specific symbol sequences, the corresponding frequency domain signal is larger than the filter bandwidth and has redundancy. In the prior art, there is no single-carrier modulation scheme that supports this situation to achieve a good compromise between spectrum efficiency and PAPR.

[0007] Summary of the Invention

[0008] The embodiments of the present application provide a signal modulation method and related devices, which perform single-carrier modulation on a first symbol sequence in which the phase difference between two adjacent symbols is 90°, provide a single-carrier modulation scheme for spectrum compression in the frequency domain, improve spectrum efficiency, and generate a single-carrier signal with low PAPR.

[0009] In the first aspect, the present application provides a signal modulation method, which is applied to a first device. The first device can be a terminal device or a chip in a terminal device, or a network device or a chip in a network device. The method includes: obtaining a first symbol sequence and performing single-carrier modulation on the first symbol sequence, wherein the phase difference between two adjacent symbols in the first symbol sequence is 90°, and the single-carrier modulation includes spectrum adjustment and frequency domain spectrum shaping FDSS based on a first scaling factor, and the spectrum adjustment includes spectrum compression; determining the signal generated by the first symbol sequence after the single-carrier modulation.

[0010] In an embodiment of the present application, a method for determining a first scaling factor corresponding to a first symbol sequence is provided, and a description of spectrum adjustment for a bandwidth compression scenario in which a first symbol sequence in which the phase difference between two adjacent symbols is 90° according to the first scaling factor is added, thereby improving spectrum efficiency and generating a single-carrier signal with low PAPR.

[0011] In some possible implementations, the first scaling factor is determined based on a bandwidth of the first symbol sequence and a transmission bandwidth of the signal.

[0012] In some possible implementations, the first scaling factor satisfies the following formula:

[0013] Or the first scaling factor satisfies the following formula:

[0014] where β1 and α1 represent the first scaling factors.

[0015] In some possible implementations, the first scaling factor satisfies the following formula:

[0016] Or the first scaling factor satisfies the following formula:

[0017] where β and α represent the first scaling factors.

[0018] The above two formulas for calculating the first scaling factor, the former method is defined based on the bandwidth of the first symbol sequence as a reference, and the latter method is defined based on the non-redundant bandwidth of the first symbol sequence (that is, the bandwidth of the non-redundant part of the frequency domain signal corresponding to the first symbol sequence, which is equal to half of the bandwidth of the first symbol sequence) as a reference. The advantage of the former method is that the definition is intuitive and easy to calculate, that is, it is calculated based on the bandwidth value before the spectrum adjustment (the bandwidth of the first symbol sequence) and the bandwidth value after the spectrum adjustment (the transmission bandwidth). When carrying the same number of bits, the non-redundant bandwidth of the first symbol sequence is the same as the bandwidth of the orthogonal amplitude modulation QAM symbol sequence defined in the 5G new air interface NR. Therefore, when using the latter method, the network side can continue to use the existing signaling or field or protocol indicating the bandwidth expansion factor of the QAM symbol sequence to indicate the first scaling factor, thereby reducing the content of the protocol modification.

[0019] In some possible implementations, the first scaling factor satisfies the following first condition:

[0020] The maximum value of β is 1, 3, or 7; or

[0021] The maximum value of α is 0.5, 0.75, or 0.875; or

[0022] The minimum value of β is 0; or

[0023] The minimum value of α is 0.

[0024] In some possible implementations, the first scaling factor satisfies the following second condition:

[0025] The maximum value of β1 is 0, 1, or 3; or

[0026] The maximum value of α1 is 0, 0.5, or 0.75; or

[0027] The minimum value of β1 is -0.5; or

[0028] The minimum value of α1 is -1.

[0029] Bandwidth extension is beneficial for lowering the PAPR of the single-carrier signal generated by modulation, but at the expense of reduced spectrum efficiency. However, the design of the maximum value of the first scaling factor can achieve a good compromise between PAPR and spectrum efficiency.

[0030] In some possible implementations, spectrum adjustment and FDSS based on the first scaling factor include: copying the first frequency domain signal corresponding to the first symbol sequence c times to obtain a second frequency domain signal with a length of (c+1)*M, where the value of c is related to the value of β, and M is the length of the first frequency domain signal; using the M / 2*(1+β) sample values ​​in the middle of the second frequency domain signal as the input signal of the FDSS to perform the FDSS and obtain the output signal of the FDSS.

[0031] In some possible implementations, spectrum adjustment and FDSS based on the first scaling factor include: copying the first frequency domain signal corresponding to the first symbol sequence c1 times to obtain a third frequency domain signal with a length of (c1+1)*M, where the value of c1 is related to the value of β1, and M is the length of the first frequency domain signal; using the M*(1+β1) sample values ​​in the middle of the third frequency domain signal as the input signal of the FDSS to perform the FDSS and obtain the output signal of the FDSS.

[0032] This spectrum adjustment method generates a signal of length M*(1+β1) or length M / 2*(1+β) as the FDSS input based on the frequency-domain signal of length M corresponding to the first symbol sequence. This ensures that during bandwidth compression, only redundant signals are compressed, while the useful signal remains intact, ensuring lossless demodulation performance. Furthermore, this FDSS input signal design results in a single-carrier modulated signal with low PAPR.

[0033] In some possible implementations, the first symbol sequence is the second symbol sequence or the third symbol sequence, the second symbol sequence is the first symbol sequence including only the pilot, the third symbol sequence is the first symbol sequence including communication data, the demodulation reference signal DMRS is a signal generated by single-carrier modulation of the second symbol sequence, the data signal is a signal generated by single-carrier modulation of the third symbol sequence, the transmission bandwidth of DMRS is the same as that of the data signal, and the bandwidth of the second symbol sequence is equal to the bandwidth of the third symbol sequence.

[0034] In some possible implementations, the second symbol sequence is a pi / 2-binary phase shift keying (pi / 2-BPSK) symbol sequence.

[0035] In the embodiment of the present application, the pilot is subjected to the same single-carrier modulation as the communication data, so that the PAPR of the DMRS is not higher than the PAPR of the data signal, thereby obtaining accurate channel estimation from the DMRS and ensuring data signal demodulation performance.

[0036] In some possible implementations, when the first device is a terminal device or a chip in a terminal device, the method further includes: receiving a first message; when the first device is a network device or a chip in a network device, the method further includes: sending a first message, wherein the first message carries at least two of the transmission bandwidth information of the signal, the length information of the first symbol sequence, or the first scaling factor information.

[0037] In some possible implementations, the first message is one of the following: downlink control information DCI, radio resource control RRC signaling, and media access control-control element MAC-CE.

[0038] In second aspect, the present application provides a communication device, which includes: a processing unit, used to obtain a first symbol sequence and perform single-carrier modulation on the first symbol sequence, wherein the phase difference between two adjacent symbols in the first symbol sequence is 90°, and the single-carrier modulation includes spectrum adjustment based on a first scaling factor and frequency domain spectrum shaping FDSS, and the spectrum adjustment includes spectrum compression; the processing unit is also used to determine the signal generated by the first symbol sequence after single-carrier modulation.

[0039] In some possible implementations, the first scaling factor is determined based on a bandwidth of the first symbol sequence and a transmission bandwidth of the signal.

[0040] In some possible implementations, the first scaling factor satisfies the following formula:

[0041] Or the first scaling factor satisfies the following formula:

[0042] where β1 and α1 represent the first scaling factors.

[0043] In some possible implementations, the first scaling factor satisfies the following formula:

[0044] Or the first scaling factor satisfies the following formula:

[0045] where β and α represent the first scaling factors.

[0046] In some possible implementations, the first scaling factor satisfies the following first condition:

[0047] The maximum value of β is 1, 3, or 7; or

[0048] The maximum value of α is 0.5, 0.75, or 0.875; or

[0049] The minimum value of β is 0; or

[0050] The minimum value of α is 0.

[0051] In some possible implementations, the first scaling factor satisfies the following second condition:

[0052] The maximum value of β1 is 0, 1, or 3; or

[0053] The maximum value of α1 is 0, 0.5, or 0.75; or

[0054] The minimum value of β1 is -0.5; or

[0055] The minimum value of α1 is -1.

[0056] Bandwidth extension is beneficial for lowering the PAPR of the single-carrier signal generated by modulation, but at the expense of reduced spectrum efficiency. However, the design of the maximum value of the first scaling factor can achieve a good compromise between PAPR and spectrum efficiency.

[0057] In some possible implementations, spectrum adjustment and FDSS based on the first scaling factor include: copying the first frequency domain signal corresponding to the first symbol sequence c times to obtain a second frequency domain signal with a length of (c+1)*M, where the value of c is related to the value of β, and M is the length of the first frequency domain signal; using the M / 2*(1+β) sample values ​​in the middle of the second frequency domain signal as the input signal of the FDSS to perform the FDSS and obtain the output signal of the FDSS.

[0058] In some possible implementations, spectrum adjustment and FDSS based on the first scaling factor include: copying the first frequency domain signal corresponding to the first symbol sequence c1 times to obtain a third frequency domain signal with a length of (c1+1)*M, where the value of c1 is related to the value of β1, and M is the length of the first frequency domain signal; using the M*(1+β1) sample values ​​in the middle of the third frequency domain signal as the input signal of the FDSS to perform the FDSS and obtain the output signal of the FDSS.

[0059] In some possible implementations, the first symbol sequence is the second symbol sequence or the third symbol sequence, the second symbol sequence is the first symbol sequence including only the pilot, the third symbol sequence is the first symbol sequence including communication data, the demodulation reference signal DMRS is a signal generated by single-carrier modulation of the second symbol sequence, the data signal is a signal generated by single-carrier modulation of the third symbol sequence, the transmission bandwidth of DMRS is the same as that of the data signal, and the bandwidth of the second symbol sequence is equal to the bandwidth of the third symbol sequence.

[0060] In some possible implementations, the second symbol sequence is a pi / 2-binary phase shift keying (pi / 2-BPSK) symbol sequence.

[0061] In some possible implementations, the method further includes: receiving a first message or sending a first message, wherein the first message carries at least two of transmission bandwidth information, length information of the first symbol sequence, or first scaling factor information.

[0062] In some possible implementations, the first message is one of the following: downlink control information DCI, radio resource control RRC signaling, and media access control-control element MAC CE.

[0063] In a third aspect, the present application provides a communication device, comprising a processor coupled to a memory, wherein when the processor executes a computer program or instruction in the memory, the method of any one of the embodiments of the first aspect is executed.

[0064] Optionally, the device further comprises a memory.

[0065] Optionally, the device further includes a communication interface, and the processor is coupled to the communication interface.

[0066] Optionally, there are one or more processors and one or more memories.

[0067] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0068] Optionally, the transceiver may include a transmitter (transmitter) and a receiver (receiver).

[0069] In one implementation, the communication device is a terminal device, or the communication device is a network device. When the communication device is a terminal device or a network device, the communication interface may be a transceiver or an input / output interface. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0070] In another implementation, the communication device is a chip or a chip system. When the device is a chip or a chip system, the communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be embodied as a processing circuit or a logic circuit.

[0071] In a fourth aspect, the present application provides a communication system, which includes the communication device of the second aspect mentioned above.

[0072] In a fifth aspect, the present application provides a computer program product, which includes: a computer program (also referred to as code, or instructions), which, when executed, enables a computer to execute a method in any possible implementation of the first aspect.

[0073] In a sixth aspect, the present application provides a computer-readable storage medium, which stores a computer program (also referred to as code, or instructions) which, when run on a computer, enables the computer to execute the method in any possible implementation of the first aspect above.

[0074] In a seventh aspect, the present application also provides a circuit comprising: a processor and an interface, for executing a computer program or instruction stored in a memory, and executing the method in any possible implementation of the first aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] FIG1 is a schematic diagram of the architecture of a communication system used in an embodiment of the present application;

[0076] FIG2 is a flowchart of an implementation of an OFDM system provided in an embodiment of the present application;

[0077] FIG3 is a schematic diagram of an SC modulation process and a frequency domain implementation of the process provided in an embodiment of the present application;

[0078] FIG4 is a schematic diagram of DFT-s-OFDM modulation including frequency domain preprocessing provided in an embodiment of the present application;

[0079] FIG5 is a schematic diagram of a bandwidth extension method and FDSS provided in an embodiment of the present application;

[0080] FIG6 is a flowchart of a single-carrier frequency domain equalization process according to an embodiment of the present application;

[0081] FIG7 is a schematic diagram showing how frequency response varies with frequency under different roll-off conditions provided by an embodiment of the present application;

[0082] FIG8 is a schematic diagram of PAPR of a QPSK DFT-s-OFDM signal combined with FDSS provided in an embodiment of the present application;

[0083] FIG9 is a schematic diagram of a complex constellation symbol splitting method provided by an embodiment of the present application;

[0084] FIG10A is a flow chart of a signal modulation method provided in an embodiment of the present application;

[0085] FIG10B is a schematic diagram of PAPRs corresponding to different first scaling factors provided in an embodiment of the present application;

[0086] FIG10C is a schematic diagram of an FDSS process provided in an embodiment of the present application;

[0087] FIG10D is a schematic diagram of an FDSS process provided in an embodiment of the present application;

[0088] FIG10E is a schematic diagram of PAPRs corresponding to different first scaling factors provided in an embodiment of the present application;

[0089] FIG11 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0090] FIG12 is a schematic diagram of the hardware structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0091] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0092] The terms "first," "second," "third," and "fourth," etc., in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, rather than to describe a specific order. In addition, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0093] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0094] "Multiple" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions is used to indicate any combination of the listed items; for example, at least one of A, B and (or) C can represent the following situations: A exists alone, B exists alone, C exists alone, A and B exist at the same time, B and C exist at the same time, A and C exist at the same time, and A, B and C exist at the same time, where A, B, and C can be single or multiple.

[0095] The embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), satellite communication system, long term evolution (LTE) system, etc. The present invention can also be applied to future communication systems, such as the sixth generation mobile communication system. The present invention 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 system or other communication systems. Figure 1 is a schematic diagram of the architecture of a communication system applied in an embodiment of the present application. As shown in Figure 1, the wireless communication system may include at least one network device, such as network device 111, network device 112, and network device 113 shown in Figure 1. The wireless communication system may also include at least one terminal device, such as terminal devices 121, 122, 123, 124, 125, 126, and 127 shown in Figure 1 . Network devices and terminal devices can communicate with each other, such as in multi-site transmission as shown in Figure 1 , where network device 112 can communicate with terminal devices 121, 122, and 123. Furthermore, enhanced mobile broadband (eMBB) transmission as shown in Figure 1 , where network devices 112 and 113 can communicate with terminal device 124. Network devices can also communicate with each other, such as in backhaul as shown in Figure 1 , where network device 111 can communicate with network devices 112 and 113. Terminal devices can also communicate with each other, such as in D2D transmission as shown in Figure 1 , where terminal device 122 can communicate with terminal device 125.

[0096] It should be understood that Figure 1 above is an exemplary illustration and the present application is not limited thereto. The present application can be applied to any communication scenario in which a transmitting device and a receiving device communicate. It should also be understood that the communication devices involved in the present application (such as a transmitting device and a receiving device) can be network devices or terminal devices. For example, the transmitting device mentioned in the present application can be a terminal device, and the receiving device can be a network device. For another example, the transmitting device mentioned in the present application can be a network device, and the receiving device can be a terminal device. For another example, both the transmitting device and the receiving device mentioned in the present application can be terminal devices. For another example, both the transmitting device and the receiving device mentioned in the present application can be network devices.

[0097] Terminal equipment in a communication system can be referred to as user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. Terminal equipment can be a device that provides voice / data connectivity to users, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. 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 autonomous 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 present application does not limit this to terminal devices in the PLMN. In vehicle-to-vehicle communication, the communication terminal on a vehicle is a terminal device, and a roadside unit (RSU) can also be a terminal device. A drone with a communication terminal on board can also be considered a terminal device.

[0098] The terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for wearable devices that use wearable technology to intelligently design and develop wearable devices for everyday 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 clothing or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are full-featured, large in size, and can achieve full or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that 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.

[0099] The terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people and machines and things.

[0100] A network device in a communication system can be a device that can communicate with a terminal device. This network device can also be called an access network device or a radio access network device. For example, the network device can be a base station. A network device can also refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. 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 eNodeB (MeNB), secondary eNodeB (SeNB), multi-standard radio (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), 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 used to be installed in the aforementioned devices or apparatuses. A base station may also refer to a mobile switching center, a device that performs base station functions in D2D, V2X, and 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. The present invention does not limit the specific technology or device form used by network equipment.

[0101] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0102] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on aircraft, balloons, and satellites. The present invention does not limit the scenarios in which the network equipment and terminal devices are deployed.

[0103] The prior art involved in this application is described below with reference to the accompanying drawings.

[0104] In radio systems, the medium that propagates a signal from a transmitter to a receiver is called a channel. Multipath is a propagation phenomenon that causes a radio signal to reach a receiver via two or more paths. Because these multiple copies of the transmitted signal travel different distances, they arrive at the receiver at different times. The difference in the time it takes for a signal to reach the receiver after traveling through different paths is called delay spread (DS). The time difference between the arrival of the first signal component along a path and the last component (which would have arrived via another path) is called the maximum delay spread (MDS).

[0105] If a signal is received at a given time and then a copy of that signal is received a fraction of a second later, the information will be "blurred" due to the temporal superposition of the signals. As MDS increases, the quality of the received signal degrades, and ultimately communication becomes impossible (i.e., the transmitted signal cannot be correctly demodulated), even when the signal level is above the receiver's sensitivity level.

[0106] During the signal transmission process, the corresponding communication link is: data to be sent → baseband signal processing at the transmitting end → RF signal processing at the transmitting end → physical channel → RF signal processing at the receiving end → baseband signal processing at the receiving end → demodulated data.

[0107] The baseband signal processing process at the transmitting end includes: input bit stream → bit mapping (bit modulation) → symbol (data sequence) → symbol modulation → signal. The symbol modulation method is, for example, OFDM modulation.

[0108] 1.OFDM technology

[0109] Please refer to FIG2 , which is a flowchart of an implementation of an OFDM system provided by an embodiment of the present application. As shown in FIG2 , a serial to parallel conversion (s-to-p) converts M consecutive data symbols into an M-dimensional data block S k =[S k [0],S k [1],…,S k [M-1]] T , subscript k is the OFDM symbol number. Through subcarrier mapping, S kThe M data carried modulates M subcarriers among the N subcarriers, and the remaining (NM) subcarriers can be understood as being modulated by 0. k A set of N complex time domain sampling points x is obtained by performing an inverse fast Fourier transform (IFFT) of N points. k =[x k [0],x k [1],…,x k [N-1]] T .

[0110] The next important operation of OFDM modulation is to insert a guard field at the beginning of each OFDM symbol to eliminate inter-symbol interference (ISI) caused by multipath propagation. The guard field is obtained by adding a cyclic prefix (CP) to the beginning of the symbol. The specific implementation is to copy x k The last G samples of x k At the beginning of the time domain OFDM signal

[0111] At the receiving end, the OFDM signal is demodulated by the inverse process. Assuming that time and frequency synchronization can be achieved and the CP length is sufficient, the CP removal operation (i.e., removing the first G samples in the received signal) results in a data block containing N samples with no ISI, which is also equal to the OFDM symbol x k The time domain circular convolution is converted into a frequency domain dot product through the fast Fourier transform (FFT), and the channel equalization can be completed with low complexity using the frequency domain single tap equalization.

[0112] 2.DFT-s-OFDM modulation

[0113] The difference between DFT-s-OFDM modulation and OFDM modulation is that there is an additional DFT process before the OFDM process, that is, for each data block s containing M data k Perform an M-point DFT operation. For details, see the dashed box in Figure 2. If DFT processing is considered a form of precoding, DFT-s-OFDM modulation can be called a precoded OFDM modulation.

[0114] Through the DFT operation, DFT-s-OFDM signals are given single-carrier characteristics, resulting in a significantly lower PAPR than multi-carrier signals like OFDM. Therefore, for the same power amplifier, DFT-s-OFDM can provide greater output power and higher power amplifier efficiency, thereby improving coverage and reducing energy consumption. The coverage and power consumption advantages of DFT-s-OFDM are particularly evident on the terminal device side, and as a result, DFT-s-OFDM is used for uplink transmission in both existing versions of LTE and NR.

[0115] s k It may include modulation symbols and / or redundant signal sampling points. The modulation symbols may be modulation symbols obtained by bit-modulating the (encoded) bit stream. Modulation methods may include pulse amplitude modulation (PAM), phase shift keying (PSK), quadrature amplitude modulation (QAM), offset quadrature amplitude modulation (OQAM), amplitude phase shift keying (APSK), etc.

[0116] The redundant signal sampling points may include phase tracking reference signal (PTRS) sampling points, unique words, zeros, and the like.

[0117] 3. Single carrier (SC) modulation

[0118] SC modulation is another symbol modulation introduced in the embodiment of this application. Please refer to Figure 3, which is a schematic diagram of an SC modulation process and the frequency domain implementation of the process provided in the embodiment of this application. As shown on the left side of Figure 3, the SC modulation process, s k After shaping and filtering, the signal x is generated k Shaping filtering involves two processes: upsampling and filtering. Filtering can be implemented as the convolution of the upsampled signal with the shaped pulse (or filter coefficient). Convolution includes linear convolution and circular convolution.

[0119] s kIncludes modulation symbols and / or redundant signal sampling points. Modulation symbols can be obtained by bit-mapping the (encoded) bit stream. Bit modulation schemes, as described above, can include PAM, PSK, QAM, OQAM, and APSK. Redundant signal sampling points can include PTRS sampling points, unique words, zeros, etc.

[0120] Time domain upsampling is equivalent to the spectrum corresponding to the data sequence in the frequency domain (denoted as S in Figure 3). k ) is periodically replicated, with the period being the width of the spectrum corresponding to the data sequence. Furthermore, cyclic convolution in the time domain corresponds to a dot product in the frequency domain. The right side of Figure 3 explains the upsampling and filtering processes from a frequency domain perspective. The rectangular grid with diagonal lines represents the spectrum corresponding to the data sequence. The green trapezoid represents the frequency response of the shaped pulse or filter. Furthermore, Figure 3 assumes that the filter bandwidth is greater than the bandwidth of the data sequence.

[0121] Time domain cyclic convolution single carrier modulation can also be equivalently implemented using frequency domain processing methods. The implementation method can be understood as DFT-s-OFDM modulation including frequency domain preprocessing, as shown in Figure 4. Figure 4 is a schematic diagram of DFT-s-OFDM modulation including frequency domain preprocessing provided by an embodiment of the present application. First, the data sequence is converted to the frequency domain by M-point DFT to obtain a frequency domain signal, such as s k Get S k Then, the frequency domain signal 1 is processed in the frequency domain, including frequency domain dot multiplication (corresponding to filtering based on time domain cyclic convolution, frequency domain dot multiplication can also be called windowing or frequency domain pulse shaping (FDSS) processing) to obtain the frequency domain signal 2. Finally, the frequency domain signal 2 is converted to the time domain through subcarrier mapping and N-point IDFT, such as by X k Get x k If the filter bandwidth is not equal to the bandwidth of frequency domain signal 1, or the number of subcarriers corresponding to the filter bandwidth (it should be understood that the number of subcarriers multiplied by the subcarrier spacing equals the bandwidth) is not equal to the number of data in frequency domain signal 1 (i.e., M), the bandwidth of frequency domain signal 1 needs to be adjusted before performing the frequency domain dot product. The adjusted bandwidth will be consistent with the filter bandwidth.

[0122] The corresponding frequency domain implementation on the right side of Figure 3 is equivalent to the bandwidth expansion and FDSS shown in Figure 5, which is a schematic diagram of a bandwidth expansion method and FDSS provided in an embodiment of the present application. The bandwidth expansion method is: S k The tail part of the signal is copied to S k In front of k The header signal is copied to S kThe signal output by the bandwidth adjustment module is used as the input of the FDSS module. The output of the FDSS module is equal to the input point multiplied by the FDSS coefficient. For example, after bandwidth expansion, the signal Its i-th value is FDSS output signal The i-th value is and The relationship between them is:

[0123] Where c[i] is the i-th FDSS coefficient.

[0124] Comparing Figure 2 and Figure 4, it can be seen that the DFT-s-OFDM modulation shown in Figure 2 is a special case of the DFT-s-OFDM modulation shown in Figure 4, that is, the bandwidth of the filter is equal to the bandwidth of the frequency domain signal 1 and the FDSS coefficient is 1 (that is, the frequency response of the filter is a rectangular window with an amplitude of 1).

[0125] 4. Single-carrier frequency domain equalization (SC-FDE) modulation

[0126] Please refer to Figure 6, which is a flowchart of a single carrier frequency domain equalization process provided by an embodiment of the present application. As shown in Figure 6, in the SC-FDE process, based on SC modulation, the data sequence is first divided into a series of data blocks s of length M by a partition module. k Each data block adds Q length CP, that is, copies s k The last Q data to s k Due to CP, the linear convolution of the multipath channel is converted into a circular convolution, and the receiver can use low-complexity single-tap frequency domain channel equalization.

[0127] 5 -Binary phase shift keying (BPSK) modulation

[0128] (can also be expressed as pi / 2-BPSK) modulation mapping maps 1 bit to a Symbols, the mapping rules defined in 5GNR are as follows:

[0129] Where b(i) represents the i-th bit, and d(i) represents the i-th Symbol. You can see that Two adjacent symbols in a symbol sequence The symbol only has a 90-degree phase jump.

[0130] 6. Roll-off, spectrum extension factor, and FDSS

[0131] As previously described, the SC modulation process includes a pulse shaping stage. Without loss of transmission performance, the filter's minimum bandwidth can be equal to the bandwidth of the symbol sequence (i.e., the width of the spectrum of the frequency domain signal corresponding to the symbol). In this case, the filter has a rectangular window frequency response.

[0132] Filters with rectangular window frequency responses are difficult to implement. To this end, roll-off is often used in practice to reduce the difficulty of filter implementation, but this increases bandwidth and reduces spectral efficiency. Roll-off is the steepness of the frequency response function with frequency. The roll-off factor is defined as:

[0133] The no-roll-off bandwidth corresponds to the bandwidth when β = 0. Please refer to Figure 7, which is a schematic diagram of the frequency response variation with frequency under different roll-off factors provided in an embodiment of the present application. β = 0 corresponds to the frequency response with a rectangular window. When β = 1, the bandwidth is doubled. When β = 0.5, the bandwidth is increased by 50%. The larger the β value, the lower the steepness of the frequency response variation with frequency, the easier it is to implement the filter, but the greater the bandwidth requirement.

[0134] In addition, regarding spectrum / bandwidth extension, there is also the following spectrum / bandwidth extension factor:

[0135] For example, if β=1, the spectrum / bandwidth expansion factor is 0.5; if β=0.5, the spectrum / bandwidth expansion factor is 1 / 3.

[0136] Further, please refer to Figure 8, which is a PAPR diagram of a quadrature phase shift keying (QPSK) DFT-s-OFDM signal combined with FDSS provided in an embodiment of the present application. As shown in Figure 8, the PAPR of the QPSK DFT-s-OFDM signal under different roll-off factors is shown. The horizontal axis represents PAPR, the vertical axis represents the complementary cumulative distribution function (CCDF), and the signal after bandwidth expansion occupies 720 subcarriers. The FDSS filter is a root raised cosine function (a Nyquist filter) with 720 coefficients. It can be seen that bandwidth extension and FDSS achieve PAPR reduction.

[0137] 7. (I, jQ) Single Carrier Modulation

[0138] (I, jQ) single carrier modulation refers to the DFT-s-OFDM or SC modulation where the input is a sequence of pure real numbers and pure imaginary numbers alternating, i.e., {x0, jy0, x1, jy1, ...} or {jy0, x0, jy1, x1, ...}, where x i and y i In this paper, {x0,jy0,x1,jy1,…} or {jy0,x0,jy1,x1,…} is called an (I,jQ) sequence.

[0139] The (I, jQ) sequence can be obtained by splitting the complex constellation symbols in the two-dimensional plane. Complex constellation symbols include: QAM, PSK, APSK, non-uniform constellations, etc. The splitting method can be seen in Figure 9, which is a schematic diagram of a complex constellation symbol splitting method provided in an embodiment of the present application. As shown in Figure 9 (a), the splitting method generates the sequence {x0, jy0, x1, jy1, ...}. As shown in Figure 9 (b), the splitting method generates the sequence {jy0, x0, jy1, x1, ...}.

[0140] In the (I, jQ) sequence, pure real numbers and pure imaginary numbers alternate, so the phase difference between two adjacent symbols is 90 degrees. If the same phase rotation is performed on each symbol in the (I, jQ) sequence, the phase difference between two adjacent symbols will still be 90 degrees.

[0141] It can also be seen that if the (I, jQ) sequence is split from the QPSK sequence, then The symbol sequence can be viewed as a phase-rotated (I, jQ) modulation. The phase rotation amount is

[0142] For (I, jQ) single-carrier modulation, the length of the (I, jQ) modulation sequence is twice the length of the complex symbol sequence (the sequence consists of I + jQ elements) while carrying the same number of bits. Theoretically, the number of resource elements (REs) required to transmit the (I, jQ) modulation sequence is twice the number of REs required to transmit the complex symbol sequence. However, the spectrum corresponding to the (I, jQ) modulation sequence contains redundancy, such as complex conjugate symmetry of the frequency domain signals at two frequency points or other special properties. This frequency domain redundancy can be removed without compromising demodulation performance, making the minimum bandwidth required to transmit the (I, jQ) modulation sequence equal to the bandwidth required to transmit the complex symbol sequence, thereby improving spectral efficiency. Therefore, if the transmission bandwidth is smaller than the bandwidth of the (I, jQ) sequence, or if the number of subcarriers contained within the transmission bandwidth (the number of subcarriers multiplied by the subcarrier spacing equals the bandwidth) is smaller than the length of the (I, jQ) sequence, bandwidth compression occurs in (I, jQ) single-carrier modulation. Existing technologies only offer bandwidth expansion, not bandwidth compression.

[0143] Based on this, please refer to FIG10A , which is a flow chart of a signal modulation method provided in an embodiment of the present application. As shown in FIG10A , the method includes the following steps:

[0144] 101. A first device obtains a first symbol sequence and performs single-carrier modulation on the first symbol sequence, wherein a phase difference between two adjacent symbols in the first symbol sequence is 90°, and the single-carrier modulation includes spectrum adjustment based on a first scaling factor and frequency domain spectrum shaping (FDSS), and the spectrum adjustment includes spectrum compression.

[0145] The first symbol sequence in the embodiment of the present application includes the aforementioned (I, jQ) sequence and its phase-rotated version.

[0146] Optionally, spectrum adjustment can also be called bandwidth adjustment. Optionally, spectrum compression can also be called bandwidth compression.

[0147] Single-carrier modulation is performed on the first symbol sequence, and single-carrier modulation may specifically refer to DFT-s-OFDM modulation or SC modulation (including SC-FDE). Spectrum adjustment and FDSS in the frequency domain correspond to the upsampling and filtering process in the time domain in FIG3 . Spectrum adjustment based on the first scaling factor includes spectrum expansion or spectrum compression of the frequency domain signal corresponding to the first symbol sequence based on the first scaling factor. The length of the frequency domain signal after spectrum adjustment is the same as the number of FDSS coefficients, or the bandwidth of the frequency domain signal after spectrum adjustment is the same as the transmission bandwidth. The frequency domain signal after spectrum adjustment is used as the input of the FDSS module to generate the FDSS module output signal.

[0148] In this process, a first scaling factor needs to be determined. The first scaling factor can be determined in one of the following ways:

[0149] (1) Determined based on the bandwidth of the first symbol sequence and the transmission bandwidth of the signal.

[0150] Specifically, the first scaling factor can be determined based on the following formula:

[0151] Alternatively, the first scaling factor may be determined based on the following formula:

[0152] Where β1 and α1 represent the first scaling factor. The signal transmission bandwidth refers to the transmission bandwidth corresponding to the output signal of the FDSS module, or in other words, the transmission bandwidth of the signal generated by single-carrier modulation of the first symbol sequence. The bandwidth of the first symbol sequence refers to the width of the spectrum of the frequency domain signal corresponding to the first symbol sequence.

[0153] When the bandwidth of the first symbol sequence is greater than the transmission bandwidth of the signal, spectrum compression may be performed on the frequency domain signal corresponding to the first symbol sequence.

[0154] When the bandwidth of the first symbol sequence is smaller than the transmission bandwidth of the signal, spectrum expansion may be performed on the frequency domain signal corresponding to the first symbol sequence.

[0155] When the bandwidth of the first symbol sequence is equal to the transmission bandwidth of the signal, the frequency domain signal corresponding to the first symbol sequence may not be processed, that is, spectrum expansion or spectrum compression is not performed.

[0156] The bandwidth can be expressed in bandwidth units, such as Hertz (Hz). Alternatively, the bandwidth can also be converted into the number of subcarriers. Specifically, the number of subcarriers = bandwidth / subcarrier spacing. A resource block (RB) contains 12 subcarriers, and the bandwidth can also be expressed in terms of the number of RBs. Through DFT, the frequency domain signal corresponding to the first symbol sequence can be obtained, and the number of frequency domain data contained therein is equal to the length of the first symbol sequence. One subcarrier carries one frequency domain data, and the bandwidth of the first symbol sequence can be calculated by multiplying the length of the first symbol sequence by the subcarrier spacing. Conversely, based on the bandwidth of the first symbol sequence, the number of data contained in the frequency domain signal corresponding to the first symbol sequence or the number of symbols in the first symbol sequence or the length of the first symbol sequence can be determined. Therefore, the above formula (4) can also be equivalently expressed as the following formula (6):

[0157] Correspondingly, the above formula (5) can also be equivalently expressed as the following formula (7):

[0158] The above values ​​of β1 and α1 have the following meanings:

[0159] When spectrum expansion or spectrum compression is not performed on the frequency domain signal corresponding to the first symbol sequence, β1=0 or α1=0;

[0160] When spectrum expansion (or bandwidth expansion) is performed on the frequency domain signal corresponding to the first symbol sequence, β1>0 or α1>0;

[0161] When spectrum compression (or bandwidth compression) is performed on the frequency domain signal corresponding to the first symbol sequence, -0.5≤β1<0 or -1≤α1<0.

[0162] Since the frequency domain signal of the first symbol sequence has at most half redundancy, that is, bandwidth compression can remove at most 50% of the redundancy, combining formula (6) and formula (7), it can be deduced that the minimum values ​​of β1 and α1 can be -0.5 and -1 respectively.

[0163] The maximum value that β1 can take is 0. Correspondingly, the maximum value that α1 can take is also 0. The transmission bandwidth of the signal corresponds to 1 times the bandwidth of the first symbol sequence.

[0164] The maximum value that β1 can take is 1. Correspondingly, the maximum value that α1 can take is 0.5. The transmission bandwidth of the signal corresponds to twice the bandwidth of the first symbol sequence.

[0165] The maximum value that β1 can take is also 3. Correspondingly, the maximum value that α1 can take is 0.75. The transmission bandwidth of the signal corresponds to 4 times the bandwidth of the first symbol sequence.

[0166] The larger the β1 value is, the lower the PAPR of the single-carrier signal generated based on the first symbol sequence in combination with FDSS can be.

[0167] (2) Determined based on half the bandwidth of the first symbol sequence and the transmission bandwidth of the signal.

[0168] Specifically, the first scaling factor can be determined based on the following formula:

[0169] Alternatively, the first scaling factor may be determined based on the following formula:

[0170] Where β and α represent the first scaling factor. Consistent with the above description, the transmission bandwidth of the signal refers to the transmission bandwidth corresponding to the output signal of the FDSS module, or the transmission bandwidth of the signal generated by the first symbol sequence after single-carrier modulation. The bandwidth of the first symbol sequence refers to the width of the spectrum of the frequency domain signal corresponding to the first symbol sequence. The bandwidth of the non-redundant part of the frequency domain signal corresponding to the first symbol sequence is equal to half of the bandwidth of the first symbol sequence. Therefore, formulas (8) and (9) are defined based on the non-redundant bandwidth of the first symbol sequence as a reference. Similarly, the bandwidth in formulas (8) and (9) can be expressed in bandwidth units, or can also be converted into the number of subcarriers or the number of symbols.

[0171] The above values ​​of β and α have the following meanings:

[0172] When spectrum expansion or spectrum compression is not performed on the frequency domain signal corresponding to the first symbol sequence, β=1 or α=0.5;

[0173] When spectrum expansion is performed on the frequency domain signal corresponding to the first symbol sequence, β>1 or α>0.5;

[0174] When spectrum compression is performed on the frequency domain signal corresponding to the first symbol sequence, 0≤β<1 or 0≤α<0.5, that is, the minimum values ​​of β and α are both 0.

[0175] The maximum value of β can be 1, and correspondingly, the maximum value of α can be 0.5, and the signal transmission bandwidth corresponds to 1 times the bandwidth of the first symbol sequence. In this case, no adjustment is made to the frequency domain signal corresponding to the first symbol sequence.

[0176] The maximum value of β can also be 3. Correspondingly, the maximum value of α can be 0.75, and the signal transmission bandwidth corresponds to twice the bandwidth of the first symbol sequence. That is, the frequency domain signal corresponding to the first symbol sequence is bandwidth-extended by a maximum of 2 times.

[0177] The maximum value of β can also be 7. Correspondingly, the maximum value of α can be 0.875, and the signal transmission bandwidth corresponds to 4 times the bandwidth of the first symbol sequence. That is, the frequency domain signal corresponding to the first symbol sequence is bandwidth-extended by a maximum of 4 times.

[0178] Further, referring to Figure 10B , which is a schematic diagram illustrating PAPRs corresponding to different first scaling factors according to an embodiment of the present application, shows the PAPRs of a DFT-s-OFDM signal carrying a first symbol sequence when β is 0, 1, 3, and 7, respectively. It can be seen that as β increases, or the degree of bandwidth expansion increases, the PAPR decreases.

[0179] Similarly, when β1 takes the values ​​of 1 and 3 respectively, the PAPR can be reduced effectively through bandwidth expansion.

[0180] It can be seen that in the embodiment of the present application, a description of the spectrum adjustment of the first symbol sequence in the bandwidth compression scenario according to the first scaling factor is added, which solves the corresponding single-carrier modulation when the bandwidth of the first symbol sequence is greater than the transmission bandwidth of the signal. In addition, the above two methods of determining the first scaling factor, the former method can be directly calculated based on the transmission bandwidth and the bandwidth of the first symbol sequence, which is convenient for calculation. As mentioned earlier, the first symbol sequence may be obtained by splitting the QAM symbol sequence. When carrying the same number of bits, the non-redundant bandwidth of the first symbol sequence is the same as the bandwidth of the QAM symbol sequence. Therefore, when adopting the latter method, the network side can continue to use the existing signaling or field or protocol that indicates the bandwidth expansion factor of the QAM symbol sequence (for example, the protocol defines the QAM symbol sequence bandwidth expansion factor as or ) indicates the first scaling factor, reducing protocol modifications. Finally, the proposed maximum and minimum values ​​of the first scaling factor can achieve a good compromise between PAPR and spectral efficiency for a single carrier signal carrying the first symbol sequence.

[0181] In the embodiments of the present application, the first device may be a network device. When the first device is a network device, after determining the transmission bandwidth (or scheduling bandwidth) of the signal and the bandwidth (or length) of the first symbol sequence, a first scaling factor may be calculated, and the first symbol sequence may be modulated based on the first scaling factor, and the modulated signal may be transmitted. Furthermore, the second device (terminal device) receives the signal.

[0182] Optionally, when the first device is a network device, the method further includes: the first device sends a first message, wherein the first message carries at least two of signal transmission bandwidth information, first symbol sequence length information, or first scaling factor information.

[0183] Optionally, when the first device is a terminal device, the method further includes: receiving a first message.

[0184] Optionally, the first message is one of the following: downlink control information (DCI), radio resource control (RRC) signaling, and media access control (MAC) control element (CE).

[0185] When the first device is a network device, the transmission bandwidth information, such as the number of physical RBs included in the transmission bandwidth, the length information of the first symbol sequence, such as the number of symbols included in the first symbol sequence, or at least two of the first scaling factor information can also be sent to the terminal device through the first message, so that the terminal device can demodulate the relevant symbol sequence according to the first scaling factor and the length of the first symbol sequence.

[0186] The length information of the first symbol sequence may be used to obtain bandwidth information of the first symbol sequence.

[0187] In this case, the terminal device may be a second device configured to receive the first message. The terminal device determines the first scaling factor information and the length of the first symbol sequence based on at least two of the transmission bandwidth information, the length (or bandwidth) information of the first symbol sequence, or the first scaling factor information carried in the first message, so that the terminal device can demodulate and obtain the first symbol sequence.

[0188] Optionally, the method further includes: the first device receiving the first message. In this case, the first device is a terminal device.

[0189] Correspondingly, the second device sends the first message. In this case, the second device is a network device. The terminal device determines the first scaling factor information and the length of the first symbol sequence based on at least two of the transmission bandwidth information, the length (or bandwidth) information of the first symbol sequence, or the first scaling factor information carried in the first message. Then, single-carrier modulation is performed on the first symbol sequence to generate a single-carrier signal, which is sent to the second device. The interaction logic between the network device and the terminal device is the same as described above and will not be repeated here.

[0190] During this process, the network device can indicate the signal transmission bandwidth, the length (bandwidth) information of the first symbol sequence, and any two parameters of the first scaling factor to the terminal device through a first message, thereby saving the transmission of related signaling. The network device can also indicate to the terminal device which specific method is used to determine the first scaling factor, so that the sender and receiver can better modulate and demodulate the signal based on the corresponding method. In addition, the network device and the terminal device can also agree in advance or determine through an agreement which method is used to determine the first scaling factor, thereby reducing signaling overhead.

[0191] In addition, the first message can be sent via DCI, which can trigger the sending of the first message when needed, ensuring flexibility in message sending. Alternatively, the first message can be sent via RRC signaling, which can reduce signaling overhead. Alternatively, the first message can be sent via MAC CE, which can further reduce signaling overhead.

[0192] After obtaining the first scaling factor, spectrum adjustment can be performed based on the first scaling factor, followed by FDSS. First, assume that a first symbol sequence of length M is processed through an M-point DFT to obtain a frequency domain signal of length M. Spectrum adjustment and FDSS are then performed as follows:

[0193] (1) For the case where the first scaling factor is determined according to the bandwidth of the first symbol sequence.

[0194] For example, let's use the aforementioned β1 as the first scaling factor. First, the first symbol sequence is subjected to an M-point DFT to obtain a first frequency domain signal of length M. This first frequency domain signal is replicated c1 times to obtain a second frequency domain signal of length (c1+1)*M. The value of c1 is related to the value (range) of β1. For example, if 0 < β1 ≤ 1, then c1 = 1; if 1 < β1 ≤ 3, then c1 = 3. M can be a power of 2, 3, or 5.

[0195] Then, the M(1+β1) (representing M times 1+β1, and the subsequent interpretation of such expressions is the same and will not be repeated here) samples in the middle of the second frequency domain signal are used as the input signal of the FDSS, and the FDSS is performed according to the above formula (1) to obtain the FDSS output signal. The bandwidth of the FDSS output signal is the same as the transmission bandwidth of the (single carrier) signal generated after single-carrier modulation.

[0196] Please refer to Figure 10C, which is a schematic diagram of an FDSS process provided in an embodiment of the present application. As shown in Figure 10C (a), bandwidth expansion and FDSS are shown when 0 < β1 ≤ 1, and as shown in Figure 10C (b), bandwidth expansion and FDSS are shown when 1 < β1 ≤ 3. The trapezoid in the figure is an example of FDSS, and the single rectangle is an example of the first frequency domain signal (length M).

[0197] As described above, β1 can also be -0.5 ≤ β1 ≤ 0. In this case, there is no need to replicate the frequency domain signal. It can be understood that if -0.5 ≤ β1 ≤ 0, then c1 = 0. The M(1 + β1) samples in the middle of the M-length first frequency domain signal are directly used as the FDSS input signal, and the FDSS is performed according to the aforementioned formula (1) to obtain the FDSS output signal. As shown in Figure 10C (c), the trapezoidal shape is an example of FDSS.

[0198] (2) For the case where the first scaling factor is determined according to half the bandwidth of the first symbol sequence.

[0199] For example, let's use the aforementioned β as the first scaling factor. First, the first symbol sequence is subjected to an M-point DFT to obtain a first frequency domain signal of length M. This first frequency domain signal is replicated c times to obtain a third frequency domain signal of length (c1+1)*M. The value of c is related to the value (range) of β. If 1 < β ≤ 3, then c = 1; if 3 < β ≤ 7, then c = 3. M is also the length of the first symbol sequence, and M can be a power of 2, 3, or 5.

[0200] Then the middle of the (c+1)M long frequency domain signal The sample values ​​are used as the input signal of FDSS, and FDSS is performed according to the above formula (1) to obtain the output signal of FDSS.

[0201] Please refer to Figure 10D, which is a schematic diagram of an FDSS process provided by an embodiment of the present application. As shown in (a) of Figure 10D, bandwidth expansion and FDSS are performed when 1 < β ≤ 3, and as shown in (b) of Figure 10D, bandwidth expansion and FDSS are performed when 3 < β ≤ 7. The trapezoid in the figure is an example of FDSS, and the single rectangle is an example of the first frequency domain signal.

[0202] As described above, the value of β can also be 0≤β≤1. In this case, there is no need to copy the frequency domain signal. It can be understood that if 0≤β≤1, then c=0. Directly copy the middle of the M-length first frequency domain signal The samples are used as FDSS inputs and FDSS is performed according to the above formula (1). As shown in (c) of Figure 10D, the trapezoid is an example of FDSS.

[0203] Further, please refer to Figure 10E, which is a schematic diagram of PAPR corresponding to different first scaling factors provided by an embodiment of the present application. As shown in Figure 10E, the FDSS shape used when β is 0, 1, 3, and 7 is shown. When β = 0 (bandwidth compression), the FDSS filter coefficients are rectangular windows, while when β = 1 (no bandwidth expansion or compression), the FDSS filter coefficients are root raised cosine functions.

[0204] As can be seen, in the embodiments of the present application, this method is used for spectrum adjustment. Specifically, based on the frequency domain signal of length M corresponding to the first symbol sequence, a signal of length M*(1+β1) or length M / 2*(1+β) is generated as the FDSS input. This ensures that when bandwidth is compressed, only redundant signals are compressed, while useful signals are not compressed, resulting in lossless signal demodulation performance. Furthermore, this FDSS input signal design results in a single-carrier modulated signal with low PAPR.

[0205] 102. The first device determines a signal generated by single-carrier modulation of a first symbol sequence.

[0206] After obtaining the FDSS output signal, it can be subjected to subcarrier mapping and IDFT, etc. For details, please refer to the DFT-s-OFDM modulation process in Figure 2. Furthermore, it can be subjected to RF signal processing to obtain the transmission signal.

[0207] As can be seen, in the embodiments of the present application, a method for determining a first scaling factor corresponding to a first symbol sequence is provided, and a description of spectrum adjustment based on the first scaling factor for a bandwidth compression scenario in which the phase difference between two adjacent symbols is 90° is added. This improves frequency efficiency and generates a single-carrier signal with low PAPR.

[0208] In an optional example, the application may also include:

[0209] 103. The first device transmits a signal generated by single-carrier modulation of the first symbol sequence to the second device. In response, the second device receives the signal and obtains the first symbol sequence based on demodulation corresponding to the single-carrier modulation process of the first symbol sequence.

[0210] In an optional example, the first symbol sequence is the second symbol sequence or the third symbol sequence. The second symbol sequence is the first symbol sequence including only the pilot. The second symbol sequence is known to the first device and the second device. The third symbol sequence is the first symbol sequence including the communication data.

[0211] When the first symbol sequence is the second symbol sequence, the second symbol sequence is modulated by a single carrier to obtain a demodulation reference signal (DMRS). When the first symbol sequence is the third symbol sequence, the third symbol sequence is modulated by a single carrier to obtain a data signal. The bandwidth of the second symbol sequence is the same as the bandwidth of the third symbol sequence, and the transmission bandwidth allocated to the DMRS and the data signal is also the same. Correspondingly, the first scaling factor of the second symbol sequence is also the same as the first scaling factor of the third symbol sequence, and both perform the same single carrier modulation and obtain a corresponding single carrier signal. For the specific modulation process, please refer to the above description and will not be repeated here.

[0212] Furthermore, the second symbol sequence is Symbol sequence.

[0213] The DMRS and the data signal are located within a scheduling period. The second device performs channel estimation based on the received DMRS and the local second symbol sequence, which is used for equalization and demodulation of the received data signal to obtain a third symbol sequence.

[0214] In the above embodiment, the pilot symbols and the data symbols are modulated using the same single carrier, so that the PAPR of the DMRS is no higher than the PAPR of the data signal, thereby accurately estimating the channel from the DMRS and ensuring the data signal demodulation performance.

[0215] As shown in the structural diagram of the communication device in FIG11, the embodiment of the present application further provides a communication device 1100, which can be a terminal device or a network device, or can be used for but not limited to a terminal device or a network device. The communication device 1100 includes a processing unit 1101. The processing unit 1101 can be or can be deployed in a processor.

[0216] a processing unit 1101 configured to obtain a first symbol sequence and perform single-carrier modulation on the first symbol sequence, wherein a phase difference between two adjacent symbols in the first symbol sequence is 90°, and the single-carrier modulation includes spectrum adjustment based on a first scaling factor and frequency domain spectrum shaping (FDSS), wherein the spectrum adjustment includes spectrum compression;

[0217] The processing unit 1101 is further configured to determine a signal generated by single-carrier modulation of the first symbol sequence.

[0218] Optionally, the first scaling factor is determined based on a bandwidth of the first symbol sequence and a transmission bandwidth of the signal.

[0219] Optionally, the first scaling factor satisfies the following formula:

[0220] Or the first scaling factor satisfies the following formula:

[0221] where β1 and α1 represent the first scaling factors.

[0222] Optionally, the first scaling factor satisfies the following formula:

[0223] Or the first scaling factor satisfies the following formula:

[0224] where β and α represent the first scaling factors.

[0225] Optionally, the first scaling factor satisfies the following first condition:

[0226] The maximum value of β is 1, 3, or 7; or

[0227] The maximum value of α is 0.5, 0.75, or 0.875; or

[0228] The minimum value of β is 0; or

[0229] The minimum value of α is 0.

[0230] Optionally, the first scaling factor satisfies the following second condition:

[0231] The maximum value of β1 is 0, 1, or 3; or

[0232] The maximum value of α1 is 0, 0.5, or 0.75; or

[0233] The minimum value of β1 is -0.5; or

[0234] The minimum value of α1 is -1.

[0235] Optionally, the spectrum adjustment and FDSS based on the first scaling factor include:

[0236] The spectrum adjustment and FDSS based on the first scaling factor include: copying the first frequency domain signal corresponding to the first symbol sequence c times to obtain a second frequency domain signal with a length of (c+1)*M, where the value of c is related to the value of β, and M is the length of the first frequency domain signal; using the M / 2*(1+β) sample values ​​in the middle of the second frequency domain signal as the input signal of the FDSS to perform the FDSS and obtain the output signal of the FDSS.

[0237] Optionally, spectrum adjustment and FDSS based on the first scaling factor include: copying the first frequency domain signal corresponding to the first symbol sequence c1 times to obtain a third frequency domain signal of length (c1+1)*M, where the value of c1 is related to the value of β1, and M is the length of the first frequency domain signal; using the M*(1+β1) sample values ​​in the middle of the third frequency domain signal as the input signal of the FDSS to perform the FDSS to obtain the output signal of the FDSS.

[0238] Optionally, the first symbol sequence is the second symbol sequence or the third symbol sequence, the second symbol sequence is the first symbol sequence including only the pilot, the third symbol sequence is the first symbol sequence including communication data, the demodulation reference signal DMRS is a signal generated by single-carrier modulation of the second symbol sequence, the data signal is a signal generated by single-carrier modulation of the third symbol sequence, the transmission bandwidth of DMRS is the same as that of the data signal, and the bandwidth of the second symbol sequence is equal to the bandwidth of the third symbol sequence.

[0239] Optionally, the second symbol sequence is a pi / 2-binary phase shift keying (pi / 2-BPSK) symbol sequence.

[0240] Optionally, the method further includes: receiving a first message or sending a first message, wherein the first message carries at least two of transmission bandwidth information, length information of the first symbol sequence, or first scaling factor information.

[0241] Optionally, the first message is one of the following: downlink control information DCI, radio resource control RRC signaling, and media access control-control element MAC-CE.

[0242] Optionally, the communication device 11000 may further include a transceiver unit 1102 for transmitting and receiving signals with other devices. The transceiver unit 1102 may be or may be deployed in a unit or module capable of transmitting and receiving information, such as a transceiver, a transceiver antenna, an input / output interface, or the like.

[0243] As shown in FIG12 , FIG12 shows a schematic diagram of the hardware structure of a communication device 1300 in an embodiment of the present application. The structure of the communication device 1100 can refer to the structure shown in FIG12 . The communication device 1300 includes: a processor 111 and a transceiver 112, wherein the processor 111 and the transceiver 112 are electrically coupled;

[0244] The processor 111 is configured to execute part or all of the computer program instructions in the memory. When the part or all of the computer program instructions are executed, the device executes the method described in any one of the above embodiments.

[0245] The transceiver 112 is configured to communicate with other devices; for example, a first device sends a first symbol sequence to a second device through a transmission signal spectrum corresponding to the first symbol sequence modulated by a single carrier.

[0246] Optionally, a memory 113 is also included for storing computer program instructions. Optionally, the memory 113 (memory #1) is located within the device, the memory 113 (memory #2) is integrated with the processor 111, or the memory 113 (memory #3) is located outside the device.

[0247] It should be understood that the communication device 1300 shown in FIG9 may be a chip or circuit. For example, the chip or circuit may be provided within a terminal device or a communication device. The transceiver 112 may also be a communication interface. A transceiver includes a receiver and a transmitter. Furthermore, the communication device 1300 may also include a bus system.

[0248] Among them, the processor 111, memory 113, and transceiver 112 are connected via a bus system. The processor 111 is used to execute instructions stored in the memory 113 to control the transceiver to receive and transmit signals, thereby completing the steps of the transmitting end or the receiving end in the implementation method involved in this application. The memory 113 can be integrated into the processor 111 or set separately from the processor 111.

[0249] As an implementation method, the functions of the transceiver 112 can be implemented by a transceiver circuit or a dedicated transceiver chip. The processor 111 can be implemented by a dedicated processing chip, a processing circuit, a processor, or a general-purpose chip. The processor can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor can further include a hardware chip or other general-purpose processor. The above-mentioned hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), and other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., or any combination thereof. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0250] It should also 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). It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0251] An embodiment of the present application provides a computer storage medium storing a computer program, wherein the computer program includes instructions for executing the method corresponding to the first device or the second device in the above embodiment.

[0252] An embodiment of the present application provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the method corresponding to the first device or the second device in the above embodiment.

[0253] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0254] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0255] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0256] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0257] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0258] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0259] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0260] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A signal modulation method, characterized in that: The method comprises: Acquire a first symbol sequence, and perform single carrier modulation on the first symbol sequence, wherein the phase difference between two adjacent symbols in the first symbol sequence is 90°, and the single carrier modulation includes spectrum adjustment based on a first scaling factor and frequency domain spectrum shaping FDSS, and the spectrum adjustment includes spectrum compression; Determine a signal generated by the first symbol sequence after being modulated by the single carrier.

2. The method according to claim 1, characterized in that The first scaling factor is determined based on a bandwidth of the first symbol sequence and a transmission bandwidth of the signal.

3. The method according to claim 2, characterized in that The first scaling factor satisfies the following formula: Or the first scaling factor satisfies the following formula: where β and α represent the first scaling factors.

4. The method according to claim 3, characterized in that The first scaling factor satisfies the following first condition: The maximum value of β is 1, 3, or 7; or The maximum value of α is 0.5, 0.75, or 0.875; or The minimum value of β is 0; or The minimum value of α is 0.

5. The method according to any one of claims 1 to 4, characterized in that: The spectrum adjustment and frequency domain spectrum shaping FDSS based on the first scaling factor includes: The first frequency domain signal corresponding to the first symbol sequence is copied c times to obtain a second frequency domain signal with a length of (c+1)*M, where the value of c is related to the value of β, and M is the length of the first frequency domain signal; The FDSS is performed using the M / 2*(1+β) sample values ​​in the middle of the second frequency domain signal as the input signal of the FDSS to obtain the output signal of the FDSS.

6. The method according to any one of claims 1 to 5, characterized in that: The first symbol sequence is the second symbol sequence or the third symbol sequence, the second symbol sequence is the first symbol sequence including only the pilot, the third symbol sequence is the first symbol sequence including communication data, the demodulation reference signal DMRS is a signal generated by the second symbol sequence after being modulated by the single carrier, the data signal is a signal generated by the third symbol sequence after being modulated by the single carrier, the transmission bandwidth of the DMRS is the same as that of the data signal, and the bandwidth of the second symbol sequence is equal to the bandwidth of the third symbol sequence.

7. The method according to claim 6, characterized in that The second symbol sequence is a pi / 2-binary phase shift keying (pi / 2-BPSK) symbol sequence.

8. The method according to any one of claims 1 to 7, characterized in that: When the method is applied to a terminal device, the method further includes: receiving a first message, wherein the first message carries at least two of the transmission bandwidth information of the signal, the length information of the first symbol sequence, or the first scaling factor information; or When the method is applied to a network device, the method further includes: sending the first message.

9. The method according to claim 8, characterized in that The first message is one of the following: downlink control information DCI, radio resource control RRC signaling, and media access control-control element MAC-CE.

10. A communication device, characterized in that: The apparatus comprises means for executing the method according to any one of claims 1 to 9.

11. A communication device, characterized in that: The method comprises a processor configured to execute the method according to any one of claims 1-9.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium comprises instructions, which, when executed, enable the method according to any one of claims 1 to 9 to be implemented.

13. A computer program product, characterized in that The computer program product comprises instructions which, when executed, cause the method according to any one of claims 1 to 9 to be implemented.

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