Communication method and communication device

Abstract

The invention provides a communication method and communication equipment. The method comprises the steps that a first device sends a first signal and a second signal on different transmission layers to a second device through the same antenna, the first signal and the second signal are data subjected to DFT-S-OFDM processing, the modulation mode used for modulating the first signal and the second signal in the DFT-S-OFDM processing process is pi / 2-BPSK, and the modulation mode used for modulating the first signal and the second signal in the DFT-S-OFDM processing process is Pi / 2-BPSK. A phase difference of pi / 2 exists between the first signal and the second signal. Through the combination of DFT and a pi / 2-BPSK modulation mode, the PAPR can be effectively reduced on the basis of expanding the coverage area, and the first device sends the first signal and the second signal of different transmission layers through the same antenna and forms a pi / 2 phase difference, so that the second device can distinguish the first signal and the second signal transmitted on the same antenna, and the transmission efficiency of the first device is improved. And the spectrum efficiency is further improved on the basis of not increasing the PAPR.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and more particularly, to a communication method and a communication device. BACKGROUND

[0002] The orthogonal frequency division multiplexing (OFDM) technology in 5G NR has certain limitations in coping with future extreme scenarios, for example, including sensitivity to phase noise at high frequency end, energy efficiency decline caused by high peak to average power ratio (PAPR), and strict synchronization requirements. Therefore, new waveforms that can have both spectral efficiency and PAPR are needed to improve system performance. SUMMARY

[0003] The present application provides a communication method, a terminal device and a network device. The following introduces each aspect of the present application.

[0004] In a first aspect, a communication method is provided, comprising: a first device sending, through a same antenna, a first signal and a second signal on different transmission layers to a second device, wherein the first signal and the second signal are data processed by DFT-S-OFDM, a modulation mode used for modulating the first signal and a modulation mode used for modulating the second signal in the DFT-S-OFDM processing process are π / 2-BPSK, and the first signal and the second signal have a phase difference of π / 2.

[0005] In a second aspect, a communication method is provided, comprising: a second device receiving a first signal and a second signal on different transmission layers sent by a first device through a same antenna, wherein the first signal and the second signal are data processed by DFT-S-OFDM, a modulation mode used for modulating the first signal and a modulation mode used for modulating the second signal in the DFT-S-OFDM processing process are π / 2-BPSK, and the first signal and the second signal have a phase difference of π / 2.

[0006] In a third aspect, a communication device is provided, the communication device being a first device, comprising: a transceiver configured to transmit, to a second device, first and second signals on different transmission layers via a same antenna, wherein the first and second signals are data processed by DFT-S-OFDM, a modulation scheme used for modulating the first signal and a modulation scheme used for modulating the second signal in the DFT-S-OFDM are π / 2-BPSK, and the first signal has a phase difference of π / 2 with the second signal.

[0007] In a fourth aspect, a communication device is provided, the communication device being a second device, comprising: a transceiver configured to receive first and second signals on different transmission layers transmitted by a first device via a same antenna, wherein the first and second signals are data processed by DFT-S-OFDM, a modulation scheme used for modulating the first signal and a modulation scheme used for modulating the second signal in the DFT-S-OFDM are π / 2-BPSK, and the first signal has a phase difference of π / 2 with the second signal.

[0008] In a fifth aspect, a communication device is provided, comprising a transceiver, a memory, and a processor, wherein the memory is configured to store a program, and the processor is configured to invoke the program in the memory and control the transceiver to receive or transmit signals, so that the communication device performs the method in the first aspect.

[0009] In a sixth aspect, a communication device is provided, comprising a transceiver, a memory, and a processor, wherein the memory is configured to store a program, and the processor is configured to invoke the program in the memory and control the transceiver to receive or transmit signals, so that the communication device performs the method in the second aspect.

[0010] In a seventh aspect, an apparatus is provided, comprising a processor configured to invoke a program from a memory, so that the apparatus performs the method in the first aspect or the second aspect.

[0011] In an eighth aspect, a chip is provided, comprising a processor configured to invoke a program from a memory, so that a device installed with the chip performs the method in the first aspect or the second aspect.

[0012] In a ninth aspect, a computer readable storage medium is provided, having a program stored thereon, the program causing a computer to perform the method in the first aspect or the second aspect.

[0013] In a tenth aspect, a computer program product is provided, comprising a program, the program causing a computer to perform the method in the first aspect or the second aspect.

[0014] In an eleventh aspect, a computer program is provided, which causes a computer to execute the method according to the first aspect or the second aspect.

[0015] In the embodiments of the present application, the first signal and the second signal of different transmission layers are both subjected to DFT-S-OFDM processing, and the modulation mode used for modulating the first signal and the modulation mode used for modulating the second signal in the DFT-S-OFDM processing process are both π / 2-BPSK. Through the combination of DFT precoding and π / 2-BPSK modulation mode, the PAPR can be effectively reduced on the basis of expanding the coverage range; and the first device transmits the first signal and the second signal of different transmission layers through the same antenna, and forms a phase difference of π / 2 between the first signal and the second signal, so that the second device can distinguish the first signal and the second signal transmitted through the same antenna. In this way, the spectral efficiency of the system is further improved on the basis of not increasing the PAPR. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 An example of a system architecture suitable for a communication system according to embodiments of the present application.

[0017] Figure 2 An example of a process for implementing DFT-S-OFDM for multiple antennas.

[0018] Figure 3 An example of a mapping constellation diagram of a first symbol after π / 2-BPSK modulation.

[0019] Figure 4 An example of a constellation mapping diagram of odd and even symbols in the π / 2-BPSK modulation mode.

[0020] Figure 5 An example of the symmetry characteristic of the DFT-S-OFDM waveform based on π / 2-BPSK modulation in the frequency domain.

[0021] Figure 6 An example of a flowchart of a communication method according to embodiments of the present application.

[0022] Figure 7 An example of the symmetry characteristic of the DFT-S-OFDM waveform based on π / 2-BPSK modulation in the frequency domain.

[0023] Figure 8 An example of a structure diagram of a communication device according to embodiments of the present application.

[0024] Figure 9 An example of a structure diagram of a communication device according to embodiments of the present application.

[0025] Figure 10 A schematic diagram of an apparatus for communication according to embodiments of the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the present application will be described below with reference to the drawings.

[0027] Communication system Figure 1 is an example diagram of a system architecture of a communication system 100 to which embodiments of the present application can be applied. The communication system 100 can include a network device 110 and a terminal device 120. The network device 110 can be a device that communicates with the terminal device 120. The network device 110 can provide network coverage for a specific geographic area and can communicate with the terminal device 120 located within the coverage area. The terminal device 120 can access a network, such as a wireless network, through the network device 110. Optionally, the communication system 100 can also include a network controller, a mobile management entity, and other network entities, which are not limited by embodiments of the present application.

[0028] It should be understood that the technical solutions of embodiments of the present application can be applied to various communication systems, such as: a fifth generation (5G) system or new radio (NR), a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD), and the like. The technical solutions provided by the present application can also be applied to future communication systems, such as a sixth generation mobile communication system, a satellite communication system, and the like.

[0029] The technical solutions of embodiments of the present application can also be applied to wireless local area networks (WLAN), wireless fidelity (WIFI), high performance radio local area networks (HIPELAN), and the like. The technical solutions provided by embodiments of the present application can be applied to communication systems that adopt 802.11 standards. Exemplarily, the 802.11 standards include but are not limited to 802.11ax standards, 802.11be standards, 802.11bn standards, 802.11 standards of the next generation of 802.11bn (post 802.11bn), and the like.

[0030] In the embodiments of the present application, the terminal device can also be referred to as a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station (MS), a mobile terminal (MT), a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user apparatus. The terminal device in the embodiments of the present application can refer to a device providing voice and / or data connectivity for a user, and can be used to connect people, things and machines, such as handheld devices with wireless connection function, vehicle-mounted devices, etc. The terminal device can also be a mobile phone, a tablet computer (Pad), a notebook computer, a palm computer, a mobile Internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. Optionally, the terminal device can be used to act as a base station. For example, the terminal device can act as a scheduling entity, which provides sidelink signals between terminal devices in vehicle to everything (V2X) or device to device (D2D), etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and the smart home device communicate with each other without relaying the communication signals through the base station.

[0031] In embodiments of the present application, the network device can be a device for communicating with the terminal device. The network device can be an access network device or a radio access network device. For example, the network device can be a base station. The base station can broadly cover various names in the following or can be replaced by the following names, for example: Node B, evolved Node B (eNB), next generation Node B (gNB), relay station, transmitting and receiving point (TRP), transmitting point (TP), master station (MeNB), secondary station (SeNB), multi-standard wireless (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. The base station can be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. The base station can also refer to a communication module, modem, or chip for being disposed in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device assuming a base station function in device-to-device (D2D), vehicle-to-everything (V2X), machine-to-machine (M2M) communication, a network side device in a 6G network, a device assuming a base station function in a future communication system, etc. The base station can support networks of the same or different access technologies. Embodiments of the present application do not limit the specific technology and specific device form adopted by the network device. The base station can support networks of the same or different access technologies. Embodiments of the present application do not limit the specific technology and specific device form adopted by the network device. In some deployments, the network device can include a CU or a DU; or the network device includes a CU and a DU. Alternatively, the base station can include an AAU.

[0032] In addition, the base station can be fixed or mobile. For example, a helicopter or a drone can be configured to act as a mobile base station, and one or more cells can move according to the location of the mobile base station. In other examples, the helicopter or the drone can be configured to act as a device for communicating with another base station.

[0033] In other implementations, the terminal device can also include an access point station (AP STA) and / or a non-AP station (non-AP STA) in a WLAN, which can support, but is not limited to, 802.11be, 802.11bn or post 802.11bn standards; and can also support 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a and other WLAN standards of the current and future 802.11 family.

[0034] Correspondingly, the network device can also include an access point AP in a WLAN, which can support 802.11be, 802.11bn or post 802.11bn standards; and can also support 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a and other WLAN standards of the current and future 802.11 family.

[0035] The network device and the terminal device can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; can also be deployed on the water surface; and can also be deployed on aircraft, balloons and satellites in the air. The scene where the network device and the terminal device are located is not limited in the embodiments of the present application.

[0036] It should be understood that all or part of the functions of the communication device in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform such as a cloud platform.

[0037] The main driving force of waveform design in the 6G system comes from overcoming the inherent limitations of the orthogonal frequency division multiplexing technology in the 5G system in dealing with future extreme scenarios. These limitations include, for example, sensitivity to high-frequency phase noise, low energy efficiency caused by high peak-to-average power ratio, and strict synchronization requirements. Therefore, the core goal of waveform research in 6G is to seek one or more basic waveform schemes that can have higher spectral efficiency, stronger energy efficiency, greater robustness to hardware damage, and can natively support communication and perception integration and other new functions. Research on new waveforms includes enhancements based on the orthogonal frequency division multiplexing (OFDM) framework.

[0038] The new waveform in the 6G system belongs to the basic framework of the physical layer signal, and the waveform and modulation technology based on OFDM. The waveform and modulation scheme of 5G NR should be considered as the basis for 6G waveform research and as the benchmark evaluation standard for other potential technologies.

[0039] This application will study new waveform technologies for 6G systems and propose transmission schemes for wireless systems under the new waveforms. For example, considering waveform design suitable for cell edge terminals, while ensuring spectrum utilization, it will support multi-layer transmission strategies and schemes for uplink waveforms to achieve higher power uplink transmission, enhance the flexibility of uplink scheduling and frequency resource selection, and provide more flexible waveform configuration.

[0040] Coverage capability remains an area where 6G systems need to be enhanced compared to 5G systems. 5G NR supports two waveforms in the uplink: cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) and discrete fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). Among them, DFT-S-OFDM adds DFT precoding before the IFFT modulation of traditional OFDM, so that the signal has single-carrier characteristics while retaining multi-carrier orthogonality, and it has better coverage performance.

[0041] 5G NR limits DFT-S-OFDM to single-layer transmission, using CP-OFDM only as a waveform scheme for multi-layer transmission. When DFT-S-OFDM is combined with multi-layer MIMO transmission, the weighted combining of signals from each layer at the output antenna ports leads to changes in the peak-to-average power ratio (PAPR). PAPR is a key parameter for measuring coverage capability, and maintaining a low PAPR value is a crucial issue for 6G when considering multi-layer transmission. The PAPR of the waveform directly affects the efficiency of the power amplifier in the transmit link. Waveforms with higher PAPR require larger power amplifier (PA) backoff. As input power backoff increases, PA efficiency and transmitter radiated power decrease accordingly. Therefore, using a lower PAPR waveform to achieve low PA backoff is particularly important, especially in the uplink, where sufficient coverage must be ensured.

[0042] 5G systems lack support for multi-layer DFT-S-OFDM waveforms. This limitation restricts the ability to guarantee low PAPR multi-layer transmission capabilities. Typically, a key technical element in improving system capacity lies in the deployment of massive MIMO antenna arrays. The waveform scheme chosen to achieve maximum spectral efficiency needs to efficiently support MIMO communication, thereby realizing its spatial multiplexing gain and supporting multi-user operation.

[0043] As an example, such as Figure 2 The diagram illustrates the implementation process of multi-antenna DFT-S-OFDM. At the transmitting end, the raw data is encoded, modulated, and demultiplexed to form processing flows corresponding to multiple antenna paths. The signal for each antenna path undergoes DFT, subcarrier mapping (e.g., F-MAP), IFFT, and cyclic prefix insertion (CP insertion) before being transmitted through its corresponding antenna. Correspondingly, at the receiving end, each received signal undergoes CP removal, FFT, demapping (e.g., IF-MAP), minimum mean square error (MMSE), IDFT, and other processing, followed by multiplexing, LLR, and FCE to obtain the original data. In other words, traditional OFDM modulation sequentially involves: data symbols → subcarrier mapping → IFFT → transmission; DFT-S-OFDM modulation sequentially involves: data symbols → DFT precoding → subcarrier mapping → IFFT → transmission. As can be seen, compared with traditional OFDM modulation, in the DFT-S-OFDM modulation process, the data symbols are pre-coded by DFT before IFFT, which can provide single-carrier characteristics and frequency diversity, and has a lower PAPR.

[0044] Since each antenna path corresponds to an independent DFT-s-OFDM, the PAPR (Packet Regulator Ratio) can be guaranteed to remain constant during signal transmission. If precoding is added to the DFT-s-OFDM, the PAPR of each antenna will change because the transmitted signal from each antenna is no longer the original single-layer data, but a mixture of multiple DFT-s-OFDM outputs, thus altering the PAPR. If precoding is added before the DFT-s-OFDM system, the signal input to the DFT-s-OFDM system becomes a precoded weighted signal due to the influence of precoding, and no longer possesses the constant-mode characteristic of the original modulation signal.

[0045] Precoding or diversity transmission of signals across multiple antennas can combat spatially selective fading. However, in DFT-s-OFDM systems, precoding or combining spatial diversity with DFT-s-OFDM to achieve antenna gain is not feasible. Therefore, it is necessary to consider whether further support for precoding or spatial diversity can be provided. As the deployment of fixed wireless access continues to expand globally, higher uplink throughput is required. In this context, expanding the coverage of multi-layer waveforms supporting higher-order modulation becomes particularly important.

[0046] Signal transmission requires digital modulation, which relies on constellation diagrams. Constellation diagrams are used to convert digital bit streams (e.g., 0s and 1s) into analog radio frequency (RF) signals. For example, the transmitter groups a continuous binary bit stream according to the requirements of the modulation scheme; for BPSK, each bit is grouped as one group, and for QPSK, two bits are grouped as one group. Next, based on the grouped bits, the corresponding constellation point is located on the constellation diagram. This constellation point has specific coordinate values ​​(I, Q), where (I, Q) are sample values ​​used to generate the baseband signal. The waveforms of the I and Q paths maintain these voltage values ​​for one symbol period, forming a rectangular pulse. This baseband signal, including information from both the I and Q paths, is modulated onto a high-frequency carrier via RF signaling and finally transmitted through the antenna. Signals of arbitrary amplitude and phase can be synthesized using the I and Q paths.

[0047] BPSK is the simplest digital modulation scheme, which uses two phase states of the carrier wave (e.g., 0° and 180°) to represent binary 0 and 1 respectively. The constellation diagram has only two points on the I-axis (i.e., the real axis): 0 → I=+1, Q=0 → coordinate (1,0); 1 → I=-1, Q=0 → coordinate (-1, 0). When transmitting bit 0, a voltage of +1 is applied to the I-path and a voltage of 0 is applied to the Q-path; when transmitting bit 1, a voltage of -1 is applied to the I-path and a voltage of 0 is applied to the Q-path.

[0048] However, when the transmitted bit stream switches between 0 and 1, for example, ...010101..., the signal phase undergoes a momentary 180° jump. This drastic phase reversal can cause the signal amplitude (or envelope) to momentarily cross zero. This is very detrimental to power amplifiers, as they operate most efficiently in the nonlinear saturation region, while a zero-amplitude signal forces the amplifier to operate in the linear region, thus reducing efficiency and potentially causing unwanted spectral spread.

[0049] To address this, π / 2-BPSK is proposed as an improvement over traditional BPSK. π / 2-BPSK is a time-domain technique that reduces PAPR through phase rotation, achieving extremely low PAPR. Due to the lower signal peak value, the power amplifier does not require significant power back-off and can operate in a more efficient region closer to saturation. This means higher effective transmit power with the same battery power in the terminal device. Higher transmit power directly translates to greater coverage distance and more reliable signal connections, particularly beneficial for users at the cell edge.

[0050] Specifically, in π / 2-BPSK modulation, to avoid a 180° phase jump, the two consecutive symbols undergo a ±90° phase jump. Specifically, the constellation diagram is rotated using two BPSK constellation diagrams, and after each symbol cycle, the currently used constellation diagram is rotated by 90° (i.e., π / 2). For example, the two constellation diagrams are: constellation diagram set A, including points (1, 0) and (-1, 0), i.e., the classic BPSK constellation; and constellation diagram set B, including points (0, 1) and (0, -1), i.e., set A has been rotated by 90°.

[0051] The transmitter can select the corresponding constellation point from two constellation diagram sets based on the bit to be transmitted. For example, starting with set A, the constellation point corresponding to bit 0 is (1, 0) in set A and (0, 1) in set B; the constellation point corresponding to bit 1 is (-1, 0) in set A and (0, -1) in set B. After transmitting one symbol, regardless of the bit transmitted, the constellation diagram is rotated 90° and switched to the other constellation diagram set, for example, set A → set B → set A → set B.

[0052] Taking the bit sequence to be transmitted as 1001 as an example. The initial constellation set is set A. When sending bit 1, the constellation point (I, Q) = (-1, 0) is selected, with a phase of approximately 180°. After transmission, the signal switches to set B. When sending bit 0, the constellation point (I, Q) = (0, 1) is selected, with a phase of approximately 90°. After transmission, the signal switches to set A. When sending bit 1 again, the constellation point (I, Q) = (-1, 0) is selected, with a phase of approximately 180°. After transmission, the signal switches to set B. When sending bit 0 again, the constellation point (I, Q) = (0, -1) is selected, with a phase of approximately 270° (or -90°). It can be seen that the maximum phase transition between adjacent symbols changes from 180° to ±90°. A phase transition of ±90° will not cause the signal amplitude to cross zero, and the signal envelope ripple is smaller. This makes the signal less sensitive to the nonlinear effects of the power amplifier, allowing the amplifier to operate closer to the saturation region, thereby significantly improving the power amplifier efficiency.

[0053] Furthermore, to obtain a lower PAPR, I-path and Q-path balance is required. Therefore, the constellation points of π / 2-BPSK are mapped in the directions of 45° and 225°, that is, a phase rotation of π / 4 is performed. For example, the mapping method of π / 2-BPSK is shown in Equation (1).

[0054] Formula (1); in, b(i) This refers to the input bits, or information bits, for example, the encoded bits. d(i) This represents the modulated symbol. The first symbol's mapping constellation diagram is as follows: Figure 3 As shown.

[0055] It is evident that in this π / 2-BPSK modulation scheme, since the constellation points are mapped in the directions of 45° and 225°, the I and Q paths are balanced, thus resulting in a lower PAPR in the DFT-s-OFDM system compared to BPSK.

[0056] QPSK, with its larger number of constellation points and independent I and Q signals, exhibits higher randomness and variability in the data sequence input to the DFT. This leads to a higher probability of peak values ​​in the IFFT output (time-domain signal), resulting in a higher PAPR. π / 2-BPSK, with fewer constellation points than QPSK, essentially constrains the input sequence, reducing the effective constellation point variation and significantly decreasing the probability of extreme peak values ​​in the time domain, thus achieving a lower PAPR. However, π / 2-BPSK modulation is still limited by the inherent limitations of BPSK modulation, with a maximum spectral efficiency limit of 1 bit / resource unit. Therefore, π / 2-BPSK suffers from a spectral efficiency bottleneck. In a "1-transmit 4-receive (1T4R)" configuration, with a signal-to-noise ratio (SNR) less than -13dB, π / 2-BPSK exhibits higher spectral efficiency than QPSK. However, as the SNR increases, above -13dB, the spectral efficiency of π / 2-BPSK stops improving, while QPSK's spectral efficiency continues to increase.

[0057] As an example, Figure 4 The constellation mapping diagram of odd and even symbols in the π / 2-BPSK modulation scheme is shown.

[0058] Because the π / 2-BPSK modulation method rotates with the odd / even sign, the DFT-S-OFDM waveform obtained based on π / 2-BPSK exhibits frequency domain symmetry. For example, as... Figure 5As shown, taking an 8-point DFT as an example, the allocated resources are divided into a first part and a second part. The first part can also be called the upper part, and the second part can be called the lower part. The first part exhibits conjugate symmetry; that is, among the multiple subcarriers in the first part, two subcarriers equidistant from the center subcarrier of the first part are complex conjugates of each other. The second part has similar characteristics. For an 8-point DFT, the first part can include subcarriers 0 to 4, and the second part can include subcarriers 5 to 7. Specifically, the signals carried on subcarriers 0 and 4 are complex conjugates of each other; the signals carried on subcarriers 1 and 3 are complex conjugates of each other; and the signals carried on subcarriers 5 and 7 are complex conjugates of each other.

[0059] To more clearly illustrate this frequency domain symmetry, let's rotate the constellation points and map them to the I and Q axes. This is equivalent to extracting the coefficient e when the odd-signed signs are mapped to the constellation points at 45° and 225°. jπ / 4 The result, for example, is the extraction of e from the signal S0 on subcarrier 0. jπ / 4 Then it is S0 / e jπ / 4； Extract e from signal S4 on subcarrier 4 jπ / 4 Then it is S4 / e j π / 4 As an example, when mapping a signal to the I-axis and Q-axis, S0 = S4 * When odd signs are mapped to constellation points 45° and 225°, it should be S0 / e. jπ / 4 = (S4 / e jπ / 4 ) * =S4 * ×e jπ / 4 For ease of description, the signals carried on different subcarriers, such as S0, S1, ..., S7, etc., all represent the signals carried on the corresponding subcarriers after removing the coefficient e. jπ / 4 The result after the influence. In the frequency domain, S0 and S4 carry the same information, S1 and S3 carry the same information, S5 and S7 carry the same information, and S2 and S6 only use the real part. That is, S0 = S4 * S1 = S3 * S5 = S7 * S2 and S6 are real numbers. * Indicates complex conjugation.

[0060] When the receiver performs signal detection, it can remove the e from the received signal. jπ / 4 The effect, for example, dividing or multiplying the received signal by e jπ / 4The signal is then processed based on its position on the I and Q axes of the constellation diagram. For example, the constellation point is located at {1, j, -1, -j}, where j = sqrt(-1). This corresponds to a phase of 0° when I = 1 and Q = 0; a phase of 90° when I = 0 and Q = 1; a phase of 180° when I = -1 and Q = 0; and a phase of 270° when I = 0 and Q = -1.

[0061] As mentioned earlier, the combination of DFT precoding and π / 2-BPSK modulation can effectively reduce PAPR while expanding coverage. However, since DFT-s-OFDM is only applicable to single-layer transmission, its spectral efficiency is limited.

[0062] Therefore, this application proposes that both the first and second signals from different transmission layers undergo DFT-S-OFDM processing. During DFT-S-OFDM processing, the first modulation scheme used to modulate the first signal and the modulation scheme used to modulate the second signal are π / 2-BPSK. By combining DFT precoding with π / 2-BPSK modulation, the PAPR (Phase Aspect Ratio) can be effectively reduced while expanding the coverage area. Furthermore, the first device transmits the first and second signals from different transmission layers through the same antenna, creating a π / 2 phase difference between them, enabling the second device to distinguish between the first and second signals transmitted on the same antenna. Thus, without increasing PAPR, the spectral efficiency of the system is further improved.

[0063] For example, two layers of content can be carried in the DFT-s-OFDM process corresponding to a single antenna. Of course, the same content can be carried on another single antenna. In this way, two layers of content are carried through two antennas and transmitted through multiple antennas in space to achieve spatial diversity. The technical solution of this application embodiment can be applied to single-antenna scenarios or to scenarios with two or more antennas.

[0064] In the embodiments of this application, the term "antenna" can also be replaced by terms such as "antenna port," "channel," or "power amplifier."

[0065] The following, combined with Figures 4 to 5 The technical solutions of the embodiments of this application will be described in detail below.

[0066] Figure 4 This is a flowchart illustrating the communication method provided in an embodiment of this application. Figure 4The method 400 shown can be performed by a first device and a second device. The first device is the sending end, and the second device is the receiving end. For example, the first device is a terminal device, and the second device is a network device; or, for example, the first device is a network device, and the second device is a terminal device. The terminal device can be, for example, a... Figure 1 The terminal device 120 shown may be, for example, a network device. Figure 1 The network device 110 shown is shown. Figure 4 The method 400 shown may include some or all of the following steps.

[0067] In step 410, the first device transmits a first signal and a second signal on different transmission layers to the second device through the same antenna.

[0068] In step 420, the second device receives the first signal and the second signal transmitted by the first device on different transmission layers under the same sky.

[0069] The first and second signals are data processed by DFT-S-OFDM. The first modulation scheme used to modulate the first signal and the modulation scheme used to modulate the second signal during DFT-S-OFDM processing are π / 2-BPSK. In other words, a combination of π / 2-BPSK modulation and DFT-S-OFDM processing is used for both the first and second signals. For example... Figure 2 The DFT-S-OFDM process shown in the figure uses π / 2-BPSK modulation in the modulation section.

[0070] In this embodiment of the application, the first signal and the second signal also have a phase difference of π / 2.

[0071] This application does not limit the timing of the formation of the phase difference in the embodiments. Optionally, the phase difference is formed after the DFT-S-OFDM processing, for example, as... Figure 2 As shown, this phase difference is formed after the addition of CP. Alternatively, the phase difference is formed before DFT precoding, for example, as... Figure 2 As shown, this phase difference is formed during the modulation process of the first and second signals (i.e., π / 2-BPSK). Alternatively, the phase difference is formed after DFT precoding, for example, as... Figure 2 As shown, the phase difference is formed after DFT precoding and before subcarrier mapping (e.g., F-MAP). Alternatively, the phase difference is formed before IFFT, for example, as... Figure 2As shown, the phase difference is formed after subcarrier mapping (e.g., F-MAP) and before IFFT. Alternatively, the phase difference is formed after IFFT, for example, as... Figure 2 As shown, the phase difference is formed after IFFT and before CP is added. The following description uses the formation of a π / 2 phase difference during π / 2-BPSK modulation of the first and second signals as an example to illustrate the technical solution of this application.

[0072] The first signal is the signal of the first transmission layer (also known as layer 1), and the second signal is the signal of the second transmission layer (also known as layer 2). Both the first and second transmission layers use π / 2-BPSK modulation, and the mapping relationship can be adjusted based on formula (1): Formula (1); in, b(i) This refers to the input bits, or information bits, for example, the encoded bits; d(i) It represents the i-th symbol after modulation (or, the modulation symbol).

[0073] Assuming that the input bits are mapped to the I-axis or Q-axis of the constellation diagram when using π / 2-BPSK modulation, the modulation method used in the first transmission layer is, for example, as shown in formula (2.1).

[0074] Formula (2.1); in, This refers to the i-th input bit, also known as the information bit, for example, the encoded bit; It is the i-th symbol (or modulation symbol) among the multiple symbols corresponding to the first signal.

[0075] In order to have a phase difference of π / 2 between the second signal and the first signal, the modulation method used by the second transmission layer can be any one of formulas (3.1) to (10.1).

[0076] Formula (3.1); Formula (4.1); Formula (5.1); Formula (6.1); Formula (7.1); Formula (8.1); Formula (9.1); Formula (10.1); in, This refers to the i-th input bit, also known as the information bit, for example, the encoded bit; Let i be the i-th symbol among the multiple symbols corresponding to the second signal.

[0077] Furthermore, assuming that when using π / 2-BPSK modulation, the input bits are mapped to positions with a phase difference of π / 4 between them and the I-axis or Q-axis of the constellation diagram, then the modulation method used in the first transmission layer is, for example, as shown in formula (2.2).

[0078] Formula (2.2); in, This refers to the i-th input bit, also known as the information bit, for example, the encoded bit; It is the i-th symbol (or modulation symbol) among the multiple symbols corresponding to the first signal.

[0079] In order to have a phase difference of π / 2 between the second signal and the first signal, the modulation method used by the second transmission layer can be any one of formulas (3.2) to (10.2).

[0080] Formula (3.2); Formula (4.2); Formula (5.2); Formula (6.2); Formula (7.2); Formula (8.2); Formula (9.2); Formula (10.2); in, This refers to the i-th input bit, also known as the information bit, for example, the encoded bit; It is the i-th symbol (or modulation symbol) among the multiple symbols corresponding to the first signal.

[0081] It should be noted that the modulation formulas for the first and second transmission layers may also have other variations, as long as the modulated first and second signals have a phase difference of π / 2. In other words, the modulation method of the second transmission layer is phase-rotated by π / 2 relative to the modulation method of the first transmission layer.

[0082] Subsequently, the first device can combine the modulated first and second signals from different transmission layers (e.g., perform weighting, summing, or other operations on the first and second signals) and execute other steps in the DFT-S-OFDM process, such as beamforming, adding CP, and gain control. Then, the first device transmits the combined first and second signals to the second device through the same antenna. Optionally, the combining operation of the first and second signals can occur before, after, or between any step in the DFT-S-OFDM processing; for example, the combining of the first and second signals can occur after DFT precoding, after signal modulation, or after the DFT-S-OFDM processing itself.

[0083] After merging, the first and second signals are mapped onto multiple subcarriers for transmission. In this application embodiment, the number of mapped subcarriers is not limited. For example, the following examples all use 8 subcarriers as an example.

[0084] The signal carried on the nth subcarrier among the multiple subcarriers received by the second device is: r n = h n × ( S n,1 + S n,2 )+ n n Formula (11); in, r n The signal carried on the nth subcarrier, h n The coefficients are related to channel fading. S n,1 The first signal carried on the nth subcarrier. S n,2 The second signal carried on the nth subcarrier. n n It is noise.

[0085] Taking 8-point DFT precoding as an example, both the first and second signals are mapped to subcarriers 0 to 7. If, when using π / 2-BPSK modulation, the constellation points are mapped to positions with a π / 4 phase difference from the I-axis or Q-axis of the constellation diagram, then the signal obtained after rotating the first signal carried on subcarrier 0 by π / 4 is denoted as S. 0,1 The signal obtained after the first signal carried on subcarrier 1 is rotated by π / 4 is denoted as S. 1,1The signal obtained after the first signal carried on subcarrier 2 is rotated by π / 4 is denoted as S. 2,1 The signal obtained after the first signal carried on subcarrier 3 is rotated by π / 4 is denoted as S. 3,1 The signal obtained after the first signal carried on subcarrier 4 is rotated by π / 4 is denoted as S. 4,1 The signal obtained after the first signal carried on subcarrier 5 is rotated by π / 4 is denoted as S. 5,1 The signal obtained after the first signal carried on subcarrier 6 is rotated by π / 4 is denoted as S. 6,1 The signal obtained after the first signal carried on subcarrier 7 is rotated by π / 4 is denoted as S. 7,1 .

[0086] The signal obtained after rotating the second signal carried on subcarrier 0 by π / 4 is denoted as S. 0,2 The signal obtained after the second signal carried on subcarrier 1 is rotated by π / 4 is denoted as S. 1,2 The signal obtained after the second signal carried on subcarrier 2 is rotated by π / 4 is denoted as S. 2,2 The signal obtained after the second signal carried on subcarrier 3 is rotated by π / 4 is denoted as S. 3,2 The signal obtained after the second signal carried on subcarrier 4 is rotated by π / 4 is denoted as S. 4,2 The signal obtained after the second signal carried on subcarrier 5 is rotated by π / 4 is denoted as S. 5,2 The signal obtained after the second signal carried on subcarrier 6 is rotated by π / 4 is denoted as S. 6,2 The signal obtained after the second signal carried on subcarrier 7 is rotated by π / 4 is denoted as S. 7,2 .

[0087] As an example, Figure 7 A schematic diagram is shown showing the addition of a first signal and a second signal with a π / 2 phase difference after DFT precoding. When the first and second signals are processed using a combination of DFT precoding and π / 2-BPSK modulation, after subcarrier mapping, the signals exhibit symmetrical characteristics in the frequency domain. For example, the multiple subcarriers carrying the first and second signals include a first part and a second part. In the multiple subcarriers of the first part, the signals carried on two subcarriers equidistant from the center subcarrier of the first part are complex conjugates of each other. Similarly, in the multiple subcarriers of the second part, the signals carried on two subcarriers equidistant from the center subcarrier of the second part are complex conjugates of each other.

[0088] For example, the number of multiple subcarriers is 8, such as Figure 7As shown on the left, for the first signal, the signals obtained after rotating the first signal carried on multiple subcarriers by π / 4 are S... 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1 = S 7,1 * S 2,1 and S 6,1 For real numbers; such as Figure 7 As shown on the right, for the second signal, there is a phase difference of π / 2 between the second signal and the first signal. The signals obtained after rotating the second signal carried on multiple subcarriers by π / 4 are S... 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 = -S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

[0089] It should be noted that, Figure 7 The first and second signals on different subcarriers shown are signals after a phase rotation of π / 4, that is, the symbols corresponding to the first and second signals are rotated to the I-axis and Q-axis, respectively. Such signals have the aforementioned frequency domain symmetry characteristics.

[0090] For each subcarrier, it is shared by a first signal and a second signal from different transmission layers, and both signals experience the same fading. Therefore, it is difficult for the second device to separate the first and second signals transmitted on the same antenna. However, by establishing a phase difference of π / 2 between the first and second signals, the second device can separate them. The following describes the receiving end's processing method in detail, using an 8-point DFT as an example. Hereinafter, a pair of subcarriers carrying the same content will be referred to as paired subcarriers, for example, subcarrier 0 and subcarrier 4, subcarrier 1 and subcarrier 3, subcarrier 5 and subcarrier 7. Specifically, after DFT precoding, the signal carried on subcarrier 0 is a complex conjugate of the signal carried on subcarrier 4, or in other words, the content of the signal carried on subcarrier 0 is the same as that of the signal carried on subcarrier 4; the signal carried on subcarrier 1 is a complex conjugate of the signal carried on subcarrier 3, or in other words, the content of the signal carried on subcarrier 1 is the same as that of the signal carried on subcarrier 3; the signal carried on subcarrier 5 is a complex conjugate of the signal carried on subcarrier 7, or in other words, the content of the signal carried on subcarrier 5 is the same as that of the signal carried on subcarrier 7.

[0091] In some implementations, during the processing of the received signal, the second device may perform some or all of the following steps: the second device combines the signals carried on paired subcarriers, which carry mutually conjugate signals, to form a target vector; and the second device calculates the first and second signals carried on each subcarrier in the paired subcarriers based on the target vector and the complex conjugate relationship between the signals carried on the paired subcarriers. Wherein, if the constellation points are mapped to positions with a π / 4 phase difference from the I-axis or Q-axis of the constellation diagram when using π / 2-BPSK modulation, then before forming the target vector, it is also necessary to perform a π / 4 phase rotation on the signals carried on multiple subcarriers.

[0092] Taking a paired subcarrier consisting of a first subcarrier and a second subcarrier as an example, the target vector may include, for example, the signal carried on the first subcarrier; and the complex conjugate signal of the signal carried on the second subcarrier. That is, the complex conjugate of the signal carried on one of the subcarriers is taken.

[0093] When the second device performs signal detection, if it maps constellation points to positions with a π / 4 phase difference from the I-axis or Q-axis of the constellation diagram when using π / 2-BPSK modulation, then after receiving the signal, the second device can first remove the e-values ​​from the received signal. jπ / 4 The effect, for example, dividing or multiplying the received signal by e jπ / 4This is equivalent to rotating the phase of the constellation point by π / 4 so that it falls on either the I-axis or the Q-axis. The possible constellation points are then located in {1, j, -1, -j}, where j = sqrt(-1). Specifically, in the case of I = 1 and Q = 0, this corresponds to a phase of 0°; in the case of I = 0 and Q = 1, it corresponds to a phase of 90°; in the case of I = -1 and Q = 0, it corresponds to a phase of 180°; and in the case of I = 0 and Q = -1, it corresponds to a phase of 270°.

[0094] Signals on paired subcarriers carrying the same content are combined. For example, in an 8-point DFT, the paired subcarriers include subcarriers 0 and 4, subcarriers 1 and 3, and subcarriers 5 and 7. The received signals from the paired subcarriers are combined, for example... ; ; .by For example, based on the aforementioned formula (11), The signal is represented as: Formula (12); The second device combines the signals carried on subcarrier 0 and subcarrier 4 to form the following target vector, that is, by taking the complex conjugate of r4, the target vector is obtained as follows: Formula (13); Without phase rotation between the first and second signals, due to S 0,1 = S 4,1 * S 0,2 =S 4,2 * Therefore, we get: Formula (14); After removing the effects of channel fading, we get: Formula (15); The equation is underdetermined; therefore, the second device cannot separate the first and second signals based on the above equation.

[0095] When a phase rotation of π / 2 is performed between the first and second signals, due to S 0,1 = S 4,1 * S 0,2 = -S 4,2 * Therefore, based on formula (13), we can obtain: Formula (16); Furthermore, we can obtain: Formula (17); The final solution yields the first and second signals on subcarrier 0 as follows: Formula (18).

[0096] In other words, ; .

[0097] The solution for the first and second signals on other paired subcarriers can be obtained by referring to a similar process, and the final result can be: The first signals carried on subcarriers 0 to 7 are as follows: ; S 3,1 =S 1,1 * S 4,1 =S 0,1 * ; S 7,1 =S 5,1 * S 2,1 and S 6,1 It is a real number; The second signals carried on subcarriers 0 to 7 are as follows: ; S 3,2 =S 1,2 * S 4,2 =S 0,2 * ; S 7,2 =S 5,2 * S 2,2 and S 6,2 It is an imaginary number.

[0098] In summary, while π / 2-BPSK modulation can effectively reduce PAPR due to its sparse constellation mapping, it also leads to a decrease in spectral efficiency. This application proposes a solution to address the low spectral efficiency of π / 2-BPSK modulation caused by low-order modulation through joint transmission across multiple transmission layers. It proposes a solution for merging signals from two different transmission layers using the same antenna and provides corresponding waveform designs, thereby improving the accuracy of channel estimation.

[0099] In this embodiment, when the first and second signals from different transmission layers are superimposed and transmitted through a single antenna, it does not affect the PAPR caused by the scheme combining π / 2-BPSK modulation and DFT precoding. That is, the PAPR when the first and second signals are simultaneously transmitted on the antenna is equal to the PAPR when only the first signal is transmitted on the antenna, and also equal to the PAPR when only the second signal is transmitted on the antenna. Optionally, the PAPR when the first and second signals are simultaneously transmitted on the antenna is: Formula (19); Where a is the symbol sequence corresponding to the first signal, b is the symbol sequence corresponding to the second signal, c and d are weighting factors, max represents the maximum power, and E represents the average power. Here, c and d are equal, i.e., c = d.

[0100] Assume that the transmission sequence corresponding to the first signal in the first transmission layer is 'a', and the transmission sequence corresponding to the second signal in the second transmission layer is 'b'. Weighting factors 'c' and 'd' are applied to 'a' and 'b' respectively to normalize the energy. The combined transmission signal is... c a+ d b. Considering that the power of each layer should be balanced, otherwise it will affect the transmission throughput, then factors c and d should be the same.

[0101] In this embodiment, vector a corresponds to the vector composed of modulation symbols of the first transmission layer, and vector b corresponds to the vector composed of modulation symbols of the second transmission layer. Based on the modulation schemes corresponding to the first and second transmission layers, each element of vector a (e.g., modulation symbol) is orthogonal in polar coordinates. The product of each element of vector a and each element of vector b results in a constant modulus of 1. or There are ab H 0, = .

[0102] When c=d, the PAPR of the combined signal after combining the first and second signals is: Formula (20); Since both the first and second transmission layers use the same modulation scheme, namely π / 2-BPSK modulation, statistically speaking, = Therefore, we get: Formula (21); Next, calculate E. ,in, Formula (22); Where N is a vector The number of elements in the matrix, where H represents the conjugate transpose. Furthermore, = Formula (23); because, Formula (24); As mentioned above, = Therefore, we get: Formula (25); Therefore, we can obtain: = Formula (26); Therefore, the PAPR of the merged signal is: Formula (27); It is evident that when the first signal of the first transmission layer and the second signal of the second transmission layer are superimposed and transmitted through an antenna, it will not affect the PAPR caused by the scheme combining π / 2-BPSK modulation and DFT precoding.

[0103] Based on the combination of DFT precoding and π / 2-BPSK modulation, in this embodiment of the application, by establishing a π / 2 phase difference between the first signal and the second signal in different transmission layers, the first signal and the second signal can be separated by the second device when they are transmitted together through the same antenna. This reduces PAPR while expanding the coverage area and improves the spectral efficiency of the system.

[0104] The above text combined Figures 1 to 7 The method embodiments of this application are described in detail below, in conjunction with... Figures 8 to 10 The present application provides a detailed description of the apparatus embodiments. It should be understood that the descriptions of the method embodiments correspond to the descriptions of the apparatus embodiments; therefore, any parts not described in detail can be found in the foregoing method embodiments.

[0105] Figure 8 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Figure 8The communication device 800 shown is a first device, including a transceiver unit 810. The transceiver unit 810 is used to transmit a first signal and a second signal on different transmission layers to a second device via the same antenna. The first signal and the second signal are data processed by DFT-S-OFDM. The modulation scheme used to modulate the first signal and the modulation scheme used to modulate the second signal during the DFT-S-OFDM processing are π / 2-BPSK, and there is a phase difference of π / 2 between the first signal and the second signal.

[0106] In some implementations, the timing of the formation of the phase difference includes: after the DFT-S-OFDM process; or before or after the DFT precoding in the DFT-S-OFDM process; or before or after the IFFT in the DFT-S-OFDM process.

[0107] In some implementations, the phase difference is formed during the modulation process of the first signal and the second signal.

[0108] In some implementations, the i-th symbol among the multiple symbols corresponding to the first signal for: The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ;in, Let be the i-th input bit.

[0109] In some implementations, the i-th symbol among the multiple symbols corresponding to the first signal for: The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ;in, Let be the i-th input bit.

[0110] In some implementations, the plurality of subcarriers used to carry the first signal and the second signal include a first part and a second part, wherein, in the plurality of subcarriers in the first part, the signals carried on two subcarriers that are equidistant from the center subcarrier of the first part are complex conjugates of each other, and in the second part, the signals carried on two subcarriers that are equidistant from the center position of the second part are complex conjugates of each other.

[0111] In some implementations, the merging of the first signal and the second signal occurs after DFT precoding in the DFT-S-OFDM processing; or, the merging of the first signal and the second signal occurs after modulation of the first signal and the second signal; or, the merging of the first signal and the second signal occurs after the DFT-S-OFDM processing.

[0112] In some implementations, when the number of subcarriers used to carry the first signal and the second signal is 8, the signals obtained after rotating the first signal carried on the multiple subcarriers by π / 4 are respectively S 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1 = S 7,1 * S 2,1 and S 6,1 The values ​​are real numbers; the signals obtained after rotating the second signal carried on the plurality of subcarriers by π / 4 are respectively S 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 =-S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

[0113] In some implementations, the peak-to-average power ratio (PAPR) when the first signal and the second signal are transmitted simultaneously on the antenna is equal to the PAPR when only the first signal is transmitted on the antenna, and is also equal to the PAPR when only the second signal is transmitted on the antenna.

[0114] It is understood that the transceiver unit 810 is, for example, a transceiver 1030. Optionally, the communication device 800 also includes a processor 1010 and a memory 1020, see details below. Figure 10 .

[0115] Figure 9 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Figure 9 The communication device 900 shown is a second device, including a transceiver unit 910. The transceiver unit 910 is used to receive a first signal and a second signal transmitted by the first device through the same antenna on different transmission layers. The first signal and the second signal are data processed by DFT-S-OFDM. The modulation scheme used to modulate the first signal and the modulation scheme used to modulate the second signal during the DFT-S-OFDM processing are π / 2-BPSK, and there is a phase difference of π / 2 between the first signal and the second signal.

[0116] In some implementations, the i-th symbol among the multiple symbols corresponding to the first signal for: The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ;in, Let be the i-th input bit.

[0117] In some implementations, the i-th symbol among the multiple symbols corresponding to the first signal for: The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ;in, Let be the i-th input bit.

[0118] In some implementations, the plurality of subcarriers used to carry the first signal and the second signal include a first part and a second part, wherein, in the plurality of subcarriers in the first part, the signals carried on two subcarriers that are equidistant from the center subcarrier of the first part are complex conjugates of each other, and in the second part, the signals carried on two subcarriers that are equidistant from the center position of the second part are complex conjugates of each other.

[0119] In some implementations, the signal carried on the nth subcarrier among the plurality of subcarriers received by the second device is: r n = h n × ( S n,1 + S n,2 )+ n n ;in, r n The signal carried on the nth subcarrier. h n The coefficients are related to channel fading. S n,1 The first signal carried on the nth subcarrier. S n,2 The second signal carried on the nth subcarrier. n n It is noise.

[0120] In some implementations, when the number of subcarriers used to carry the first signal and the second signal is 8, the signals obtained after rotating the first signal carried on the multiple subcarriers by π / 4 are respectively S 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1= S 7,1 * S 2,1 and S 6,1 The values ​​are real numbers; the signals obtained after rotating the second signal carried on the plurality of subcarriers by π / 4 are respectively S 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 =-S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

[0121] In some implementations, the communication device 1100 further includes a processing unit 1120, configured to: perform a π / 4 phase rotation on the signals carried on the plurality of subcarriers; combine the signals carried on paired subcarriers carrying mutually conjugate signals to form a target vector; and calculate the first signal and the second signal carried on each of the paired subcarriers based on the target vector and the conjugate relationship between the signals carried on the paired subcarriers.

[0122] In some implementations, the paired subcarriers include a first subcarrier and a second subcarrier, and the target vector includes: a signal carried on the first subcarrier; and a complex conjugate signal of the signal carried on the second subcarrier.

[0123] In some implementations, when the number of the plurality of subcarriers is 8, the first signals carried on the plurality of subcarriers are as follows: ; S 3,1 =S 1,1 * S 4,1 =S 0,1 * ; S 7,1 =S 5,1 * S 2,1 and S 6,1 The value is a real number; the second signals carried on the plurality of subcarriers are respectively: ; S 3,2 =S 1,2 * S 4,2 =S 0,2 * ; S 7,2 =S 5,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

[0124] It is understood that the transceiver unit 910 is, for example, a transceiver 1030, and the processing unit 920 is, for example, a processor 1010. Optionally, the communication device 900 also includes a memory 1020, see details below. Figure 10 .

[0125] Figure 10 This is a schematic structural diagram of a communication apparatus according to an embodiment of this application. Figure 10 The dashed lines shown indicate that the unit or module is optional. The device 1000 can be used to implement the methods described in the above method embodiments. The device 1000 may be, for example, a chip or a communication device.

[0126] Apparatus 1000 may include one or more processors 1010. Processor 1010 may support apparatus 1000 in implementing the methods described in the foregoing method embodiments. Processor 1010 may be a general-purpose processor or a special-purpose processor. For example, processor 1010 may be a central processing unit (CPU). Alternatively, processor 1010 may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors may be microprocessors or any conventional processor, etc.

[0127] The apparatus 1000 may further include one or more memories 1020. The memories 1020 store programs that can be executed by the processor 1010, causing the processor 1010 to perform the methods described in the above method embodiments. The memories 1020 may be independent of the processor 1010, or they may be integrated into the processor 1010.

[0128] The device 1000 may also include a transceiver 1030. The processor 1010 can communicate with other devices or chips through the transceiver 1030. For example, the processor 1010 can send and receive data with other devices or chips through the transceiver 1030.

[0129] This application also provides a communication system. The communication system includes the first device and the second device described above. In some implementations, the system further includes other devices that interact with the first device and the second device.

[0130] This application also provides a computer-readable storage medium for storing a program. This computer-readable storage medium can be applied to the first or second device provided in this application, and the program causes a computer to perform the methods executed by the first or second device in various embodiments of this application.

[0131] This application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to the first device or the second device provided in the embodiments of this application, and the program causes a computer to perform the methods executed by the first device or the second device in the various embodiments of this application.

[0132] This application also provides a computer program. This computer program can be applied to the first or second device provided in this application, and causes the computer to execute the methods performed by the first or second device in various embodiments of this application.

[0133] It should be understood that the terms "system" and "network" in the embodiments of this application can be used interchangeably. Furthermore, the terminology used in this application is only for explaining specific embodiments of this application and is not intended to limit this application. The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0134] In the embodiments of this application, the term "instruction" can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0135] In the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0136] In the embodiments of this application, the term "correspondence" can indicate a direct or indirect correspondence between two things, or an association between two things, or a relationship such as instruction and being instructed, configuration and being configured.

[0137] In this application embodiment, "predefined" or "preconfigured" can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including a first device and a second device). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

[0138] In this application embodiment, the "protocol" may refer to a standard protocol in the field of communication, such as the LTE protocol, the NR protocol, and related protocols applied to future communication systems. This application does not limit this.

[0139] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0140] In the various embodiments of this application, the order of the above-mentioned processes does not imply 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 this application.

[0141] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0142] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0143] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0144] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can read or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0145] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, include: The first device transmits a first signal and a second signal on different transmission layers to the second device through the same antenna. The first signal and the second signal are data processed by DFT-S-OFDM. The modulation method used to modulate the first signal and the modulation method used to modulate the second signal during the DFT-S-OFDM process are π / 2-BPSK. The first signal and the second signal have a phase difference of π / 2.

2. The method according to claim 1, characterized in that, The timing of the formation of the phase difference includes: After the DFT-S-OFDM processing procedure; or, Before or after DFT precoding in the DFT-S-OFDM processing; or... The process of processing DFT-S-OFDM before or after IFFT.

3. The method according to claim 1 or 2, characterized in that, The phase difference is formed during the modulation process of the first signal and the second signal.

4. The method according to any one of claims 1 to 3, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

5. The method according to any one of claims 1 to 3, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

6. The method according to any one of claims 1 to 5, characterized in that, The plurality of subcarriers used to carry the first signal and the second signal include a first part and a second part, wherein, in the plurality of subcarriers in the first part, the signals carried on two subcarriers that are equidistant from the center subcarrier of the first part are complex conjugates of each other, and in the second part, the signals carried on two subcarriers that are equidistant from the center position of the second part are complex conjugates of each other.

7. The method according to any one of claims 1 to 6, characterized in that, The merging of the first and second signals occurs after the DFT precoding in the DFT-S-OFDM processing; or, The merging of the first signal and the second signal occurs after the modulation of the first signal and the second signal; or, The merging of the first and second signals occurs after the DFT-S-OFDM processing.

8. The method according to any one of claims 1 to 7, characterized in that, When the number of subcarriers used to carry the first signal and the second signal is 8, The signals obtained after the first signal carried on the plurality of subcarriers is rotated by π / 4 are S 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1 = S 7,1 * S 2,1 and S 6,1 For real numbers, * Indicates complex conjugation; The signals obtained after the second signal carried on the plurality of subcarriers is rotated by π / 4 are S 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 =-S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

9. The method according to any one of claims 1 to 8, characterized in that, The peak-to-average power ratio (PAPR) when the first signal and the second signal are transmitted simultaneously on the antenna is equal to the PAPR when only the first signal is transmitted on the antenna, and is also equal to the PAPR when only the second signal is transmitted on the antenna.

10. A communication method, characterized in that, include: The second device receives a first signal and a second signal transmitted by the first device through the same antenna on different transmission layers. The first signal and the second signal are data processed by DFT-S-OFDM. The modulation scheme used to modulate the first signal and the modulation scheme used to modulate the second signal during the DFT-S-OFDM process are π / 2-BPSK. The first signal and the second signal have a phase difference of π / 2.

11. The method according to claim 10, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

12. The method according to claim 10, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

13. The method according to any one of claims 10 to 12, characterized in that, The plurality of subcarriers used to carry the first signal and the second signal include a first part and a second part, wherein, in the plurality of subcarriers in the first part, the signals carried on two subcarriers that are equidistant from the center subcarrier of the first part are complex conjugates of each other, and in the second part, the signals carried on two subcarriers that are equidistant from the center position of the second part are complex conjugates of each other.

14. The method according to any one of claims 10 to 13, characterized in that, The signal carried on the nth subcarrier among the multiple subcarriers received by the second device is: r n = h n × ( S n,1 + S n,2 )+ n n ； in, r n The signal carried on the nth subcarrier, h n The coefficients are related to channel fading. S n,1 The first signal carried on the nth subcarrier. S n,2 The second signal carried on the nth subcarrier. n n It is noise.

15. The method according to any one of claims 1 to 14, characterized in that, When the number of subcarriers used to carry the first signal and the second signal is 8, the signals obtained after the first signal carried on the multiple subcarriers are rotated by π / 4 are S, respectively. 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1 = S 7,1 * S 2,1 and S 6,1 For real numbers, * Indicates complex conjugation; The signals obtained after the second signal carried on the plurality of subcarriers is rotated by π / 4 are S 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 =-S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

16. The method according to any one of claims 10 to 15, characterized in that, The method further includes: The second device performs a π / 4 phase rotation on the signals carried on the plurality of subcarriers; The second device combines the signals carried on paired subcarriers, which carry mutually conjugate signals, to form a target vector; The second device calculates the first signal and the second signal carried on each subcarrier in the paired subcarriers based on the target vector and the complex conjugate relationship between the signals carried on the paired subcarriers.

17. The method according to claim 16, characterized in that, The paired subcarriers include a first subcarrier and a second subcarrier, and the target vector includes: The signal carried on the first subcarrier; and, The complex conjugate signal carried on the second subcarrier.

18. The method according to any one of claims 14 to 17, characterized in that, When the number of the plurality of subcarriers is 8, the first signals carried on the plurality of subcarriers are as follows: ; ;S 3,1 =S 1,1 * ; S 4,1 =S 0,1 * ; ;S 7,1 =S 5,1 * ; S 2,1 and S 6,1 For real numbers, * Indicates complex conjugation; The second signals carried on the plurality of subcarriers are respectively: ; ;S 3,2 =S 1,2 * ; S 4,2 =S 0,2 * ; ;S 7,2 =S 5,2 * ; S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

19. A communication device, characterized in that, The communication device is a first device, comprising: The transceiver unit is used to transmit a first signal and a second signal on different transmission layers to a second device through the same antenna. The first signal and the second signal are data processed by DFT-S-OFDM. The modulation method used to modulate the first signal and the modulation method used to modulate the second signal during the DFT-S-OFDM process are π / 2-BPSK. The first signal and the second signal have a phase difference of π / 2.

20. The device according to claim 19, characterized in that, The timing of the formation of the phase difference includes: After the DFT-S-OFDM processing procedure; or, Before or after DFT precoding in the DFT-S-OFDM processing; or... The process of processing DFT-S-OFDM before or after IFFT.

21. The device according to claim 19 or 20, characterized in that, The phase difference is formed during the modulation process of the first signal and the second signal.

22. The device according to any one of claims 19 to 21, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

23. The device according to any one of claims 19 to 21, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

24. The device according to any one of claims 19 to 23, characterized in that, The plurality of subcarriers used to carry the first signal and the second signal include a first part and a second part, wherein, in the plurality of subcarriers in the first part, the signals carried on two subcarriers that are equidistant from the center subcarrier of the first part are complex conjugates of each other, and in the second part, the signals carried on two subcarriers that are equidistant from the center position of the second part are complex conjugates of each other.

25. The device according to any one of claims 19 to 24, characterized in that, The merging of the first and second signals occurs after the DFT precoding in the DFT-S-OFDM processing; or, The merging of the first signal and the second signal occurs after the modulation of the first signal and the second signal; or, The merging of the first and second signals occurs after the DFT-S-OFDM processing.

26. The device according to any one of claims 19 to 25, characterized in that, When the number of subcarriers used to carry the first signal and the second signal is 8, The signals obtained after the first signal carried on the plurality of subcarriers is rotated by π / 4 are S 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1 = S 7,1 * S 2,1 and S 6,1 For real numbers, * Indicates complex conjugation; The signals obtained after the second signal carried on the plurality of subcarriers is rotated by π / 4 are S 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 =-S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

27. The device according to any one of claims 19 to 26, characterized in that, The peak-to-average power ratio (PAPR) when the first signal and the second signal are transmitted simultaneously on the antenna is equal to the PAPR when only the first signal is transmitted on the antenna, and is also equal to the PAPR when only the second signal is transmitted on the antenna.

28. A communication device, characterized in that, The communication device is a second device, including: The transceiver unit is used to receive a first signal and a second signal transmitted by the first device through the same antenna on different transmission layers, wherein the first signal and the second signal are data processed by DFT-S-OFDM, and the modulation method used to modulate the first signal and the modulation method used to modulate the second signal during the DFT-S-OFDM processing are π / 2-BPSK, and there is a phase difference of π / 2 between the first signal and the second signal.

29. The device according to claim 28, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

30. The device according to claim 28, characterized in that, The i-th symbol among the multiple symbols corresponding to the first signal for: ； The i-th symbol among the multiple symbols corresponding to the second signal for: ;or, ;or, ;or, ;or, ;or, ;or, ;or, ； in, Let be the i-th input bit.

31. The device according to any one of claims 28 to 30, characterized in that, The plurality of subcarriers used to carry the first signal and the second signal include a first part and a second part, wherein, in the plurality of subcarriers in the first part, the signals carried on two subcarriers that are equidistant from the center subcarrier of the first part are complex conjugates of each other, and in the second part, the signals carried on two subcarriers that are equidistant from the center position of the second part are complex conjugates of each other.

32. The device according to any one of claims 28 to 31, characterized in that, The signal carried on the nth subcarrier among the multiple subcarriers received by the second device is: r n = h n × ( S n,1 + S n,2 )+ n n ； in, r n The signal carried on the nth subcarrier, h n The coefficients are related to channel fading. S n,1 The first signal carried on the nth subcarrier. S n,2 The second signal carried on the nth subcarrier. n n It is noise.

33. The device according to any one of claims 1 to 32, characterized in that, When the number of subcarriers used to carry the first signal and the second signal is 8, the signals obtained after the first signal carried on the multiple subcarriers are rotated by π / 4 are S, respectively. 0,1 S 1,1 S 2,1 S 3,1 S 4,1 S 5,1 S 6,1 and S 7,1 , among which, S 0,1 = S 4,1 * S 1,1 = S 3,1 * S 5,1 = S 7,1 * S 2,1 and S 6,1 For real numbers, * Indicates complex conjugation; The signals obtained after the second signal carried on the plurality of subcarriers is rotated by π / 4 are S 0,2 S 1,2 S 2,2 S 3,2 S 4,2 S 5,2 S 6,2 and S 7,2 , among which, S 0,2 =-S 4,2 * S 1,2 = -S 3,2 * S 5,2 = -S 7,2 * S 2,2 and S 6,2 It is an imaginary number. * Indicates complex conjugation.

34. The device according to any one of claims 28 to 33, characterized in that, It also includes a processing unit for: The signals carried on the multiple subcarriers are phase-rotated by π / 4. The signals carried on paired subcarriers, which carry mutually conjugate signals, are combined to form a target vector; Based on the target vector and the complex conjugate relationship between the signals carried on the paired subcarriers, the first signal and the second signal carried on each subcarrier in the paired subcarriers are calculated.

35. The device according to claim 34, characterized in that, The paired subcarriers include a first subcarrier and a second subcarrier, and the target vector includes: The signal carried on the first subcarrier; and, The complex conjugate signal carried on the second subcarrier.

36. The device according to any one of claims 32 to 35, characterized in that, When the number of the plurality of subcarriers is 8, the first signals carried on the plurality of subcarriers are as follows: ; ;S 3,1 =S 1,1 * ; S 4,1 =S 0,1 * ; ;S 7,1 =S 5,1 * ; S 2,1 and S 6,1 It is a real number; The second signals carried on the plurality of subcarriers are respectively: ; ;S 3,2 =S 1,2 * ; S 4,2 =S 0,2 * ; ;S 7,2 =S 5,2 * ; S 2,2 and S 6,2 It is an imaginary number.

37. A communication device, characterized in that, The device includes a transceiver, a memory, and a processor. The memory stores a program, and the processor invokes the program in the memory and controls the transceiver to receive or transmit signals so that the communication device performs the method according to any one of claims 1 to 9.

38. A communication device, characterized in that, The device includes a transceiver, a memory, and a processor. The memory stores a program, and the processor invokes the program in the memory and controls the transceiver to receive or transmit signals so that the communication device performs the method according to any one of claims 10 to 18.

39. An apparatus, characterized in that, Includes a processor for calling a program from memory to cause the apparatus to perform the method according to any one of claims 1 to 18.

40. A chip, characterized in that, Includes a processor for calling a program from memory, causing a device on which the chip is mounted to perform the method according to any one of claims 1 to 18.

41. A computer-readable storage medium, characterized in that, It contains a program that causes a computer to perform the method according to any one of claims 1 to 18.

42. A computer program product, characterized in that, Includes a program that causes a computer to perform the method according to any one of claims 1 to 18.

43. A computer program, characterized in that, The computer program causes the computer to perform the method according to any one of claims 1 to 18.

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