Communication methods and devices

Abstract

This application discloses a communication method and apparatus, relating to the field of communication technology, to reduce signaling overhead between network devices and terminal devices during data transmission. The method includes: a terminal device receiving a reference signal sent by a network device, the reference signal being correlated with a weight matrix U and the channel between the network device and the terminal device; the weight matrix U having N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device; subsequently, the terminal device determining an estimation result of the weight matrix U based on the reference signal; the estimation result of the weight matrix U being used by the terminal device for signal detection of data signals received from the network device, or the estimation result of the weight matrix U being used by the terminal device for precoding data signals sent to the network device.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] In a multiple-input multiple-output (MIMO) system, network devices (such as base stations) can estimate uplink channel information using the sounding reference signal (SRS) received from terminal devices. Subsequently, the base station can estimate downlink channel information based on this uplink channel information and the reciprocity of uplink and downlink channels in time-division duplex (TDD) mode.

[0003] During uplink data transmission, network devices can design the precoding matrix for terminal devices based on uplink channel information and then send this precoding matrix information to the terminal devices. The terminal devices then precode the uplink data signals according to this precoding matrix information, pre-eliminating inter-stream interference and ensuring that the network devices receive uplink data signals free from inter-stream interference. However, sending this precoding matrix information typically leads to high signaling overhead, especially when the precoding matrix is ​​at the sub-band level or even the RB (resource block) level (i.e., the network device needs to send the precoding matrix of the terminal devices for each sub-band or even each RB to the terminal devices).

[0004] Accordingly, during downlink data transmission, network devices design precoding based on downlink channel information to pre-eliminate interference between downlink data streams, thus ensuring that terminal devices receive downlink data signals free from inter-stream interference. However, this process of using network device precoding to eliminate inter-stream interference may result in a loss of network device transmit power, leading to a decrease in the received signal-to-noise ratio (SNR) of the terminal device. To address this issue, a feasible technique is to employ symbol-level precoding (SLP), which effectively superimposes the inter-stream interference signals with the data signals, enabling the terminal device to more accurately recover the data signals transmitted by the network device. For example... Figure 1As shown in the Quadrature Phase Shift Keying (QPSK) constellation diagram, assuming the data signal transmitted by the network device is OA, using a traditional precoding scheme can eliminate interference between data streams, ensuring the data signal received by the terminal device is exactly OA. However, using Symbol-Level Precoding (SLP), the interference signal between data streams can be adjusted to AB, ensuring the data signal received by the terminal device is OB. Compared to data signal OA, data signal OB is further away from the QPSK constellation decision threshold (i.e., the aforementioned effective superposition), therefore, Symbol-Level Precoding (SLP) has better noise immunity. In other words, Symbol-Level Precoding (SLP) can effectively expand the constellation points in the QPSK constellation diagram, thereby improving the received signal-to-noise ratio (SNR) of the terminal device. However, in Symbol-Level Precoding (SLP), to achieve effective superposition of the interference signal and the data signal, the network device needs to know the detection matrix of the data signal detected by the terminal device. Therefore, the network device typically needs to determine this detection matrix and send it to the terminal device. However, sending this detection matrix information also leads to high signaling overhead, especially when the precoding matrix is ​​at the sub-band level or even the RB level.

[0005] In summary, whether in the uplink or downlink data transmission process, network devices may need to send a certain weight matrix (for uplink, it corresponds to the terminal device's precoding matrix, and for downlink, it corresponds to the terminal device's detection matrix) to the terminal device, and this sending process usually results in high signaling overhead. Summary of the Invention

[0006] This application provides a communication method and apparatus, in which a terminal device can determine the estimation result of a weight matrix U based on a received reference signal, so that the terminal device can perform downlink data signal detection or uplink data signal precoding based on the estimation result of the weight matrix U, thereby reducing the signaling overhead when transmitting data between network devices and terminal devices.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] Firstly, this application provides a communication method, which may include: a terminal device receiving a reference signal sent by a network device, the reference signal being correlated with a weight matrix U and the channel between the network device and the terminal device. The weight matrix U has N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device. Subsequently, the terminal device determines an estimation result of the weight matrix U based on the received reference signal. This estimation result of the weight matrix U is used by the terminal device for signal detection of data signals received from the network device, or for precoding of data signals sent to the network device by the terminal device. Since the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, the terminal device determines the corresponding estimation result of the weight matrix U based on the reference signal, enabling the terminal device to use the estimation result of the weight matrix U for signal detection or precoding of data signals. In other words, during data transmission, the network device does not need to send the weight matrix U of the terminal device to the terminal device via additional signaling, thereby reducing the signaling overhead during data transmission between the terminal device and the network device.

[0009] In one possible implementation, the estimated weight matrix U is used by the terminal device to perform signal detection on the data signal received from the network device. This includes multiplying the estimated weight matrix U by the data signal received from the network device to perform signal detection. In summary, the terminal device can perform signal detection and recover the data signal received from the network device based on the estimated weight matrix U.

[0010] In one possible implementation, the estimated weight matrix U is used by the terminal device to precode the data signal it sends to the network device. This includes multiplying the estimated weight matrix U with the data signal sent to the network device by the terminal device to perform precoding. In summary, the terminal device can precode the data signal based on the estimated weight matrix U, thus determining the precoded data signal to be sent to the network device.

[0011] In one possible implementation, the method further includes: the terminal device receiving first information sent by the network device. This first information is used to instruct the terminal device that the estimation result of the weight matrix U is used for signal detection of the data signals it receives from the network device.

[0012] In one possible implementation, the method further includes: the terminal device receiving first information sent by the network device. This first information is used to instruct the terminal device to use the estimation result of the weight matrix U for precoding the data signals it sends to the network device.

[0013] In other words, after receiving the first information from the network device, the terminal device, according to the instructions of the first information, uses the estimation result of the weight matrix U obtained by the terminal device based on the reference signal to realize signal detection of the (downlink) data signal or precoding of the (uplink) data signal, thereby enabling the terminal device to recover the data signal received from the network device or enabling the network device to recover the data signal received from the terminal device. Furthermore, during data transmission, the terminal device can directly obtain the estimation result of the weight matrix U based on the received reference signal. That is, the network device does not need to send the weight matrix U of the terminal device to the terminal device through additional signaling. Therefore, through the above process, the signaling overhead during data transmission between the terminal device and the network device can be reduced.

[0014] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix P = αH H (HH H ) -1 U is determined. Here, H represents the channel between the network device and the terminal device, H... H Let α denote the conjugate transpose of H, where α is a real number.

[0015] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix U. or Determined. Here, H represents the channel between the network device and the terminal device. H Let H denote the conjugate transpose of H, where α is a real number, 1 is an N1 / N2×1 dimensional vector of all 1s, N1 is the number of receiving ports of the terminal device, and N2 is the number of transmitting ports of the terminal device.

[0016] In one possible implementation, α is related to the transmit power of the network device.

[0017] In one possible implementation, the method further includes: the terminal device receiving second information sent by the network device, the second information being used to indicate α. Through the above process, the terminal device can determine α based on the second information sent by the network device, and determine the estimation result of the weight matrix U based on α and the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal device, thereby enabling the terminal device to recover the data signal received from the network device or enabling the network device to recover the data signal received from the terminal device.

[0018] In one possible implementation, the terminal device receives third information sent by the network device. This third information indicates the correlation between the terminal device's reference signal and the weight matrix U, that is, the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal device. Through the above process, after receiving the third information sent from the network device, the terminal device can obtain the correlation between the reference signal and the weight matrix U indicated by the third information, and then, based on this correlation, after receiving the reference signal sent by the network device, obtain the estimation result of the weight matrix U based on the reference signal.

[0019] Secondly, this application provides a communication method, comprising: a network device sending a reference signal to a terminal device, the reference signal being correlated with a weight matrix U and the channel between the network device and the terminal device. The weight matrix U has N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device. The reference signal is used by the terminal device to determine an estimation result of the weight matrix U. This estimation result is used by the terminal device to perform signal detection on data signals received from the network device, or to precode data signals sent to the network device. After the network device sends the reference signal to the terminal device, because the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, the terminal device, upon receiving the reference signal, can determine the corresponding estimation result of the weight matrix U based on the reference signal, so that the terminal device can use the estimation result of the weight matrix U for signal detection or precoding of data signals, etc. In other words, during data transmission, the network device does not need to send information about the weight matrix U of the terminal device to the terminal device through additional signaling, thereby reducing the signaling overhead when the terminal device and the network device transmit data.

[0020] In one possible implementation, the method further includes: the network device sending first information to the terminal device. This first information is used to instruct the terminal device that the estimation result of the weight matrix U is used for signal detection of the data signals it receives from the network device.

[0021] In one possible implementation, the method further includes: the network device sending first information to the terminal device. The first information is used to instruct the terminal device that the estimation result of the weight matrix U is used to precode the data signal it sends to the network device.

[0022] In summary, after the network device sends the first information to the terminal device, the terminal device can, according to the instructions of the first information, use the estimation result of the weight matrix U obtained by the terminal device based on the reference signal to realize signal detection of the (downlink) data signal or precoding of the (uplink) data signal, thereby enabling the terminal device to recover the data signal received from the network device or enabling the network device to recover the data signal received from the terminal device. Furthermore, during data transmission between the terminal device and the network device, the terminal device can directly obtain the estimation result of the weight matrix U based on the reference signal. That is, the network device does not need to send the weight matrix U of the terminal device to the terminal device through additional signaling. Therefore, through the above process, the signaling overhead during data transmission between the terminal device and the network device can be reduced.

[0023] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix P = αH H (HH H ) -1 U is determined. Here, H represents the channel between the network device and the terminal device, H... H Let α denote the conjugate transpose of H, where α is a real number.

[0024] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix U. or Determined. Here, H represents the channel between the network device and the terminal device. H Let H denote the conjugate transpose of H, where α is a real number, 1 is an N1 / N2×1 dimensional vector of all 1s, N1 is the number of receiving ports of the terminal device, and N2 is the number of transmitting ports of the terminal device.

[0025] Among them, α is related to the transmission power of the network device.

[0026] In one possible implementation, the network device sends second information to the terminal device, which indicates α. Through the above process, after the network device sends the second information to the terminal device, the terminal device can determine α according to the indication of the second information sent by the network device, and determine the estimation result of the weight matrix U according to α, the aforementioned reference signal, the weight matrix U, and the correlation between the channel between the network device and the terminal device, thereby enabling the terminal device to recover the data signal received from the network device or enabling the network device to recover the data signal received from the terminal device.

[0027] In one possible implementation, the network device sends third information to the terminal device. This third information indicates the correlation between the terminal device's reference signal and the weight matrix U, specifically the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal device. Through this process, after the network device sends the third information to the terminal device, the terminal device can obtain the correlation between the reference signal and the weight matrix U according to the instructions in the third information. Then, based on this correlation, upon receiving the reference signal from the network device, the terminal device can obtain an estimate of the weight matrix U.

[0028] Thirdly, this application provides a communication apparatus for implementing the communication method described in the first aspect. This communication apparatus can be deployed on a terminal device; that is, it can be a terminal device or an apparatus that supports the terminal device in implementing the method described in the first aspect. The communication apparatus includes a receiving unit and an estimation unit: the receiving unit is used for the terminal device to receive a reference signal transmitted by a network device. The reference signal is associated with a weight matrix U and the channel between the network device and the terminal device. The weight matrix U has N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device. Subsequently, the estimation unit is used to determine an estimation result of the weight matrix U based on the reference signal received by the receiving unit. The estimation result of the weight matrix U is used by the terminal device for signal detection of data signals received from the network device, or for precoding of data signals transmitted by the terminal device to the network device.

[0029] In one possible implementation, the communication device further includes a signal detection unit: the signal detection unit is used to multiply the estimated result of the weight matrix U with the data signal received by the terminal device from the network device to perform signal detection.

[0030] In one possible implementation, the communication device further includes a precoding unit: the precoding unit is used to multiply the estimated result of the weight matrix U with the data signal sent by the terminal device to the network device to perform precoding.

[0031] In one possible implementation, the receiving unit is further configured to receive first information sent by the network device. This first information is used to instruct the terminal device to use the estimation result of the weight matrix U for signal detection of the data signal received by the terminal device from the network device.

[0032] In one possible implementation, the receiving unit is further configured to receive first information sent by the network device. This first information is used to instruct the terminal device to use the estimation result of its weight matrix U for precoding the data signal sent from the terminal device to the network device.

[0033] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix P = αH H (HH H ) -1 U is determined. Here, H represents the channel between the network device and the terminal device, H... H Let α denote the conjugate transpose of H, where α is a real number.

[0034] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix U. or Determined. Here, H represents the channel between the network device and the terminal device. H Let H denote the conjugate transpose of H, where α is a real number, 1 is an N1 / N2×1 dimensional vector of all 1s, N1 is the number of receiving ports of the terminal device, and N2 is the number of transmitting ports of the terminal device.

[0035] Among them, α is related to the transmission power of the network device.

[0036] In one possible implementation, the receiving unit is further configured to receive second information sent by the network device, the second information being used to indicate α.

[0037] In one possible implementation, the receiving unit is further configured to receive third information sent by the network device, which is used to indicate the correlation between the terminal device reference signal and the weight matrix U, that is, the correlation between the reference signal and the weight matrix U and the channel between the network device and the terminal device.

[0038] Fourthly, this application provides a communication apparatus for implementing the method described in the second aspect above. This communication apparatus can be deployed on a network device; that is, it can be a network device or an apparatus that supports the network device in implementing the method described in the second aspect. The communication apparatus includes a transmitting unit: the transmitting unit is used to transmit a reference signal to a terminal device, the reference signal being associated with a weight matrix U and a channel between the network device and the terminal device. The weight matrix U has N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device. The reference signal is used by the terminal device to determine the estimation result of the weight matrix U. The estimation result of the weight matrix U is used by the terminal device to perform signal detection on data signals received from the network device, or the estimation result of the weight matrix U is used by the terminal device to precode data signals transmitted to the network device.

[0039] In one possible implementation, the sending unit is further configured to send first information to the terminal device. This first information is used to instruct the terminal device that the estimation result of the weight matrix U is used for signal detection of the data signals received from the network device.

[0040] In one possible implementation, the sending unit is further configured to send first information to the terminal device. The first information is used to instruct the terminal device that the estimation result of the weight matrix U is used for precoding the data signals it sends to the network device.

[0041] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix P = αH H (HH H ) -1 U is determined. Here, H represents the channel between the network device and the terminal device, H... H Let α denote the conjugate transpose of H, where α is a real number.

[0042] In one possible implementation, the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, specifically including: the reference signal is derived from the matrix U. or Determined. Here, H represents the channel between the network device and the terminal device. H Let H denote the conjugate transpose of H, where α is a real number, 1 is an N1 / N2×1 dimensional vector of all 1s, N1 is the number of receiving ports of the terminal device, and N2 is the number of transmitting ports of the terminal device.

[0043] Among them, α is related to the transmission power of the network device.

[0044] In one possible implementation, the sending unit is further configured to send second information to the terminal device, the second information being used to indicate α.

[0045] In one possible implementation, the transmitting unit is further configured to transmit third information to the terminal device, the third information being used to indicate the correlation between the terminal device reference signal and the weight matrix U.

[0046] Fifthly, this application provides a communication device, comprising: a processor coupled to a memory; optionally, it further comprising at least one communication interface and a communication bus; the memory is used to store computer-executable instructions, and the processor, memory, and at least one communication interface are connected via the communication bus. The processor executes the computer-executable instructions stored in the memory to enable the communication device to implement any of the communication methods provided in the first or second aspect. This device may exist in the form of a chip product.

[0047] Sixthly, this application provides a communication system, including the communication devices provided in the third and fourth aspects.

[0048] In a seventh aspect, a computer-readable storage medium is provided, including instructions that, when executed on a computer, cause the computer to perform the communication method provided by any possible implementation of the first or second aspect described above.

[0049] Eighthly, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the communication method provided by any possible implementation of the first or second aspect described above.

[0050] Ninthly, embodiments of this application provide a chip including a processor and an interface. The processor is coupled to a memory through the interface. When the processor executes a computer program or instructions in the memory, the communication method provided by any possible implementation of the first or second aspect described above is executed.

[0051] The beneficial effects of the corresponding devices for each of the above aspects can be found in the descriptions of the beneficial effects of the respective methods, and will not be repeated here. It should be noted that various possible implementations of any of the above aspects can be combined, provided that the solutions do not contradict each other. Attached Figure Description

[0052] Figure 1 This application provides a schematic diagram of the effective superposition of symbol-level precoded data signals and interference signals;

[0053] Figure 2 A schematic diagram of a communication scenario provided in this application;

[0054] Figure 3 A flowchart illustrating a communication method provided in this application Figure 1 ;

[0055] Figure 4 A flowchart illustrating a communication method provided in this application Figure 2 ;

[0056] Figure 5 A schematic diagram of data signal and DMRS resource mapping provided in this application;

[0057] Figure 6 A 16QAM constellation provided for this application Figure 1 ;

[0058] Figure 7 (a) is a 16QAM constellation provided in this application. Figure 2 ;

[0059] Figure 7 (b) is a 16QAM constellation provided in this application. Figure 3 ;

[0060] Figure 8 A schematic diagram of the composition of a communication device provided in this application Figure 1 ;

[0061] Figure 9 A schematic diagram of the composition of a communication device provided in this application Figure 2 ;

[0062] Figure 10 This application provides a hardware structure diagram of a communication device. Detailed Implementation

[0063] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document 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 alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0064] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0065] To reduce the signaling overhead required for network devices to transmit a weight matrix (corresponding to the terminal device's precoding matrix for uplink and the terminal device's detection matrix for downlink) to terminal devices, this application provides a communication method. The following will describe this application in further detail with reference to the accompanying drawings. It should be understood that the specific operational methods described in the following embodiments can also be applied to device embodiments or system embodiments.

[0066] The network elements involved in the embodiments of this application include network devices and terminal devices in a communication network, as detailed in the following examples. Figure 2 .

[0067] The communication systems in this application include, but are not limited to, long-term evolution (LTE) systems, 5G systems, NR systems, wireless local area networks (WLAN) systems, and future evolution systems or multiple converged communication systems. For example, the methods provided in this application can be specifically applied to evolved-universal terrestrial radio access network (E-UTRAN) and next-generation radio access network (NG-RAN) systems.

[0068] The network device in this application embodiment is an entity on the network side used to transmit or receive signals, or to transmit and receive signals. The network device can be a device deployed in a radio access network (RAN) to provide wireless communication functions for terminal devices. For example, it can be a transmission reception point (TRP), a base station, various types of control nodes, a road side unit (RSU), etc. The base station can be various types of macro base stations, micro base stations (also called small stations), relay stations, access points (APs), etc. For example, the base station can be an evolved NodeB (eNB or eNodeB), a next-generation node base station (gNB), a next-generation eNB (ng-eNB), a relay node (RN), an integrated access and backhaul (IAB) node, etc. In systems employing different radio access technologies (RAT), the names of devices with base station functions may differ. For example, in an LTE system, it can be called an eNB or eNodeB, and in a 5G or NR system, it can be called a gNB. This application does not limit the specific name of the base station. A control node can connect to multiple base stations and configure resources for multiple terminal devices covered by these base stations. For example, the control node can be a network controller or a radio controller (e.g., a radio controller in a cloud radio access network (CRAN) scenario). Network equipment can also be access network equipment in a future public land mobile network (PLMN), etc.

[0069] The terminal device in this application embodiment can be a user-side entity used to receive or transmit signals, or both. The terminal device is used to provide users with one or more of voice services and data connectivity services. The terminal device can also be referred to as user equipment (UE), terminal, access terminal, user unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or user device. The terminal device can be a vehicle-to-everything (V2X) device, such as a smart car, digital car, unmanned car, driverless car, pilotless car, or automobile, self-driving car, battery EV, hybrid electric vehicle (HEV), range-extended electric vehicle (REEV), plug-in hybrid electric vehicle (PHEV), or new energy vehicle. Terminal devices can also be device-to-device (D2D) devices, such as electricity meters and water meters. Terminal devices can also be mobile stations (MS), subscriber units, drones, Internet of Things (IoT) devices, stations (ST) in WLANs, cellular phones, smartphones, cordless phones, wireless data cards, tablets, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistant (PDA) devices, laptop computers, machine type communication (MTC) terminals, handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, and wearable devices (also known as wearable smart devices).Terminal devices can also serve as terminals in next-generation communication systems, such as terminals in 5G systems, terminals in future evolved PLMNs, and terminals in NR systems.

[0070] In this embodiment, the weight matrix U is determined by the network device and sent to the terminal device. This weight matrix U can be used by the terminal device for signal detection of the received (downlink) data signals, and also for precoding the (uplink) data signals sent to the network device. In other words, the weight matrix U of the terminal device can be either a detection matrix for detecting (downlink) data signals or a precoding matrix for precoding (uplink) data signals.

[0071] The following describes the two scenarios in conjunction with Examples 1 and 2:

[0072] Example 1

[0073] In this embodiment, the weight matrix U of the terminal device is the detection matrix for detecting the data signal. The detection matrix of the terminal device maximizes its received power, thereby reducing power loss. In Symbol-Level Precoding (SLP), to achieve effective superposition of interference and data signals, the network device needs to know the detection matrix for detecting the data signal of the terminal device. Therefore, the network device typically needs to determine this detection matrix and send it to the terminal device. Since the weight matrix U of the terminal device in this embodiment is the same as the detection matrix for detecting the data signal, it will be consistently described as the weight matrix U in the following description and will not be elaborated further.

[0074] In traditional precoding, the precoding used for downlink data transmission is the same as that used for DMRS transmission, allowing the terminal device to recover the data channel, including the precoding, based on the received DMRS, and thus recover the data signal received by the terminal device. However, in Symbol-Level Precoding (SLP), the data signal and interference signal received by the terminal device can be effectively superimposed, eliminating the need to recover the data signal based on the data channel estimation result, and also eliminating the need for DMRS to carry data channel information. Based on this characteristic, this embodiment can utilize DMRS to carry the weight matrix information of the terminal device, thereby reducing the signaling overhead required for the network device to send the weight matrix information to the terminal device. In other words, in the embodiments of this application, after determining the weight matrix U of the terminal device, the network device uses DMRS to carry the weight matrix information. It should be noted that the network device can also use other reference signals besides DMRS to carry the weight matrix information in practice.

[0075] like Figure 3As shown, the method includes steps S301-S303:

[0076] S301. The network device sends a reference signal to the terminal device.

[0077] Correspondingly, the terminal device receives the reference signal sent by the network device.

[0078] For example, the reference signal sent by the network device to the terminal device can be a demodulation reference signal (DMRS), etc.

[0079] The information carried on the reference signal can be orthogonal cover code (OCC) sequences, ZC (Zadoff-Chu) sequences, etc., pre-set by network devices and terminal devices.

[0080] Optionally, the network device precodes the information to be carried by the reference signal based on the precoding matrix P to obtain the reference signal, and then sends the reference signal to the terminal device. The reference signal is related to the weight matrix U and the channel between the network device and the terminal device. This channel can be an uplink channel or a downlink channel. The weight matrix U is used by the terminal device to receive data signals.

[0081] In one possible implementation, the weight matrix U has N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device.

[0082] Optionally, before the network device sends the reference signal to the terminal device, the network device determines the weight matrix U of the terminal device based on the uplink channel information it has acquired, and uses the weight matrix U to determine the reference signal to be sent to the terminal device.

[0083] For clarity and simplicity, the embodiments of this application will be described below using an example where the terminal device has only one receiving port. It should be understood that the terminal device has at least one receiving port, and the technical solution of this application can also be applied to scenarios where the terminal device has multiple receiving ports.

[0084] For example, the number of terminal devices transmitting data with the network device is K (K>=1, K is an integer), and let the weight matrix U of the k-th (K>=k>=1, k is an integer) terminal device be u. k The uplink channel of the kth terminal device obtained by the network device through SRS is The network device obtains its uplink channel with the kth terminal device. Then, it can be based on preset criteria. To determine the weight matrix U of the k-th terminal device. In other words, the network device will... u when taking the maximum value k The weight matrix U is determined to be the weight matrix of the k-th terminal device, that is, the weight matrix U can be the channel G. k The first right singular vector, when the terminal device uses this weight matrix U for signal detection, can maximize the received signal-to-noise ratio of the terminal device. Wherein, G... k Let G be the downlink channel between the network device and the k-th terminal device. k Network devices can determine the reciprocity of uplink and downlink channels, as well as the uplink channel... It has been determined.

[0085] It should be noted that network devices can determine the weight matrix U of the terminal device in the manner given in the example above, or they can determine the weight matrix U of the terminal device in other ways. For example, a column of the discrete fourier transform (DFT) matrix can be used as the weight matrix U of the terminal device.

[0086] Optionally, after determining the weight matrix U of the terminal device, the network device can determine the reference signal to be sent to the terminal device based on the weight matrix U, the reference signal and the correlation between the weight matrix U and the channel between the network device and the terminal device.

[0087] Specifically, the network device determines the precoding matrix P based on the weight matrix U of the terminal device and the aforementioned correlation, and then sends the reference signal obtained by precoding the information to be carried by the reference signal using the precoding matrix P to the terminal device. In other words, the reference signal received by the terminal device is determined by this correlation.

[0088] For example, the precoding matrix P is P = αH H (HH H ) -1 U, that is, the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal device is: Reference signal = αH H (HH H ) -1 The U× reference signal needs to carry information. Here, H represents the channel between the network device and the terminal device. H Let H represent the conjugate transpose of H, where α is a real number. In this case, during the process of the network device determining the precoding matrix P based on the weight matrix U, the channel represented by H can be a downlink channel. The dimension of H can be N1×M, where N1 is the number of receive ports of the terminal device and M is the number of transmit ports of the network device.

[0089] It should be noted that when the weight matrix U of the terminal device is the detection matrix for detecting (downlink) data signals, its relationship with the reference signal and the channel between the network device and the terminal device can differ from when the weight matrix U of the terminal device is the precoding matrix for precoding (uplink) data signals. The real number α is a power factor (also known as a compensation factor, path loss compensation factor, etc.) that is related to the transmit power of the network device. It can be used to compensate for downlink channel transmission power and limit the transmit power of the network device to meet preset constraints. An introduction to the real number α can be found here and will not be repeated in the following content.

[0090] For example, when a network device transmits data with K (K>=1, K is an integer) terminal devices, the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal devices is as follows: Where k (K>=k>=1, k is an integer) represents the k-th terminal device that transmits data with the network device, p k Let P,u be the precoding matrix used for precoding the reference signal sent to the k-th terminal device. k This represents the weight matrix U, G of the terminal device determined by the network device based on the uplink channel. k This represents the downlink channel between the network device and the k-th terminal device. In systems where channel reciprocity holds, such as TDD, it can be transmitted via the uplink channel. get, G represents k The conjugate transpose of α. k Let α be a real number. k It is related to the transmit power of network devices and is the power factor corresponding to the k-th terminal device. Regarding the real number α... k For an introduction to the real number α, please refer to the above introduction, which will not be repeated here.

[0091] It should be noted that network devices can determine the reference signal using the method given in the above example, or they can determine the reference signal using other possible implementations. The correlation given in the above example is not unique, and it can also be determined according to the actual application scenario. Furthermore, K given in the above example can also refer to the number of receiving ports of the same terminal device, in which case k is the k-th receiving port of the terminal device.

[0092] Furthermore, in this embodiment, the weight matrix U of the terminal device can be at the RB level, subband level, or wideband level. Correspondingly, the power factor can also be at the RB level, subband level, or wideband level. In this case, the signaling overhead caused by sending the power factor to the terminal device is less.

[0093] Optionally, the network device transmits the data signal and reference signal to the terminal device using different precoding methods. For example, the network device can use a precoding matrix W obtained by symbol-level precoding (SLP) to precode the data signal and send the precoded data signal to the terminal device. Then, the network device can use a precoding matrix P, which is different from the precoding matrix W obtained in the above example, to precode the information to be carried on the reference signal to obtain the reference signal, and send the reference signal to the terminal device.

[0094] For example, taking DMRS as the reference signal, such as Figure 5 As shown, on different REs (each small cell is an RE) of the same RB, data signals and DMRS are transmitted on different resource elements (REs) (time and frequency) of the RB through symbol-level precoding (SLP) and DMRS precoding, respectively. Data signals are transmitted through symbol-level precoding (SLP) on REs represented by blank cells, and DMRS is transmitted through DMRS precoding on REs represented by black cells.

[0095] In the above process, during data transmission, the network device does not need to send the weight matrix U of the terminal device to the terminal device through additional signaling, thereby reducing the signaling overhead between the terminal device and the network device when transmitting data.

[0096] S302. The terminal device determines the estimation result of the weight matrix U based on the reference signal.

[0097] Optionally, after receiving the reference signal obtained based on the precoding matrix P sent by the network device, the terminal device can estimate the weight matrix U of the terminal device carried by the reference signal based on the reference signal, the reference signal and the weight matrix U, and the correlation between the channel between the network device and the terminal device, thereby obtaining the estimation result of the weight matrix U of the terminal device.

[0098] When the weight matrix U of the terminal device is either a detection matrix for detecting (downlink) data signals or a precoding matrix for precoding (uplink) data signals, the correlation between this weight matrix U and the reference signal, as well as the channel relationship between the network device and the terminal device, differs. Therefore, optionally, before determining the estimation result of the weight matrix U, the network device may send third information to the terminal device. This third information indicates the correlation between the terminal device's reference signal and the weight matrix U. Based on the correlation indicated by the third information, the terminal device determines how it estimates the weight matrix U using the reference signal.

[0099] It should be noted that, in this first embodiment, the association relationship indicated by the third information is, for example, the association relationship given in the example of the previous step S301, namely, reference signal = αH H (HH H ) -1 The information that the U× reference signal needs to carry, or The terminal device then determines the estimation result of the weight matrix U using the following method. The method for determining the estimation result of the weight matrix U based on the reference signal in Embodiment 1 is described below with reference to an example:

[0100] For example, the reference signal received by the terminal device can be represented as y = HP + n = αU + n, where y represents the reference signal received by the terminal device from the network device. Here, n represents additive noise. That is, the reference signal received by the terminal device is the product of the terminal device's weight matrix U and α. Furthermore, for an explanation of H, P, and α, please refer to the example above. In this case, the terminal device can estimate its weight matrix U based on y / α, obtaining the estimated result of the terminal device's weight matrix U.

[0101] For example, when a network device can transmit data with K (K>=1, K is an integer) terminal devices, the reference signal received by the k-th terminal device transmitting data with the network device can also be represented as y. k =G k p k +n k =α k u k +n k Where n k This is an additive noise vector. In other words, the reference signal received by this terminal device is the weight matrix u of the k-th terminal device. k With α k The product of . Also, regarding p k u k Gk and α k The explanation can be found in the example above, and will not be repeated below. At this point, the k-th terminal device can determine the value based on y. k / α k We estimate the weight matrix U of the kth terminal device to obtain the weight matrix of the kth terminal device.

[0102] Optionally, prior to step S302, the network device may send second information to the terminal device, which indicates α. Through this process, the terminal device can determine α based on the second information sent by the network device, and can determine the estimation result of the weight matrix U based on the reference signal, α, and the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal device, thereby enabling the terminal device to recover the data signal received from the network device.

[0103] The second and third information can be different or the same. The second and third information can be signaling such as RRC, MAC-CE, and DCI. If the second and third information are the same, the signaling overhead during data transmission between the terminal device and the network device can be further reduced.

[0104] It should be noted that the way the terminal device determines its weight matrix U based on the received reference signal is not limited to the method given in the example above. For example, the terminal device can obtain its weight matrix U by performing operations such as squaring or taking the square root on the received reference signal y.

[0105] Furthermore, the terminal device can directly obtain the estimated weight matrix U based on the received reference signal during data transmission. In other words, the network device does not need to send the weight matrix U to the terminal device via additional signaling. Therefore, this process reduces the signaling overhead between the terminal device and the network device during data transmission.

[0106] S303. Based on the estimation result of the weight matrix U, the terminal device performs signal detection on the data signal received from the network device.

[0107] Optionally, before the terminal device performs signal detection on the data signal it receives from the network device, the terminal device also receives first information sent by the network device, which instructs the terminal device to use the estimation result of the weight matrix U for signal detection on the data signal it receives from the network device.

[0108] The first information can be different from or the same as at least one of the second and third information. That is, the first information can be signaling such as RRC, MAC-CE, or DCI. If the first, second, and third information are the same piece of information, the signaling overhead during data transmission between the terminal device and the network device can be further reduced.

[0109] Specifically, the terminal device multiplies the estimated weight matrix U with the data signal received from the network device to perform signal detection and obtain the signal detection result. Finally, the terminal device can determine whether the received data signal is accurate based on the signal detection result.

[0110] It should be noted that the multiplication operation between the estimated result of the weight matrix U by the terminal device and the data signal received by the terminal device from the network device can be left multiplication or right multiplication, and is not limited to matrix multiplication. It can also include element-wise multiplication, weighting, and other operations.

[0111] Finally, in Embodiment 1, since the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, the terminal device can determine the corresponding weight matrix U based on the reference signal after receiving it, so that the terminal device can use the weight matrix U for signal detection of the data signal. In other words, during data transmission, the network device does not need to send the terminal device's weight matrix U to the terminal device via additional signaling, thereby reducing the signaling overhead when the terminal device and network device transmit data.

[0112] Example 2

[0113] In this embodiment, the weight matrix U of the terminal device is the precoding matrix used by the terminal device for data signal precoding. During uplink data transmission, the network device determines the precoding matrix of the terminal device based on the uplink channel information obtained during uplink data transmission and sends this precoding matrix to the terminal device. Subsequently, the terminal device precodes the uplink data signal according to this precoding matrix, pre-eliminating inter-stream interference, thereby ensuring that the network device receives an uplink data signal free from inter-stream interference. Since the weight matrix U of the terminal device in this embodiment is the precoding matrix used for data signal precoding, it will be consistently described as the weight matrix U in the following description of this embodiment, without further elaboration.

[0114] This embodiment utilizes CSI-RS to carry the weight matrix information of the terminal device, reducing the signaling overhead required for the network device to send the weight matrix U to the terminal device, thereby reducing the signaling overhead when the network device and the terminal device transmit data. In other words, in this embodiment, after determining the weight matrix U of the terminal device, the network device uses CSI-RS to carry the weight matrix U. It should be noted that the network device may also use other reference signals besides CSI-RS to carry the weight matrix U in practice.

[0115] like Figure 4 As shown, the method includes steps S401-S403:

[0116] S401. The network device sends a reference signal to the terminal device.

[0117] Correspondingly, the terminal device receives the reference signal sent by the network device.

[0118] For example, the reference signal sent by the network device to the terminal device may be a channel state information reference signal (CSI-RS), etc.

[0119] The information carried on the reference signal can be orthogonal cover code (OCC) sequences, ZC (Zadoff-Chu) sequences, etc., pre-set by network devices and terminal devices.

[0120] Optionally, the network device precodes the information to be carried by the reference signal based on the precoding matrix P to obtain the reference signal, and then sends the reference signal to the terminal device. The reference signal is related to the weight matrix U and the channel between the network device and the terminal device. This channel can be an uplink channel or a downlink channel. The weight matrix U is used by the terminal device to transmit data signals.

[0121] In one possible implementation, the weight matrix U has N rows or columns, where N is a positive integer less than or equal to the number of receiving ports of the terminal device.

[0122] Optionally, before the network device sends the reference signal obtained based on the precoding matrix P to the terminal device, the network device determines the weight matrix U of the terminal device based on the uplink channel information it has obtained, and uses the weight matrix U to determine the reference signal to be sent to the terminal device.

[0123] For clarity and simplicity, the embodiments of this application will be described below using a terminal device with only one transmission port as an example. It should be understood that the terminal device has at least one transmission port, and the technical solution of this application can also be applied to scenarios where the terminal device has multiple transmission ports.

[0124] Examples of how network devices determine the weight matrix of terminal devices can be found in the example in Embodiment 1 above, and will not be repeated here. Similarly, network devices can determine the weight matrix U of terminal devices in the manner given in that example, or they can determine the weight matrix U of terminal devices in other ways. For example, a column of the discrete fourier transform (DFT) matrix can be used as the weight matrix U of the terminal device.

[0125] Optionally, after determining the weight matrix U of the terminal device, the network device can determine the reference signal to be sent to the terminal device based on the weight matrix U, the reference signal and the correlation between the weight matrix U and the channel between the network device and the terminal device.

[0126] Specifically, the network device determines the precoding matrix P based on the weight matrix U of the terminal device and the aforementioned correlation, and then sends the reference signal obtained by precoding the information to be carried by the reference signal using the precoding matrix P to the terminal device. In other words, the reference signal received by the terminal device is determined by this correlation.

[0127] It should be noted that when the weight matrix U of the terminal device is the detection matrix for detecting (downlink) data signals by the terminal device, or when the weight matrix U of the terminal device is the precoding matrix for precoding (uplink) data signals by the terminal device, the correlation between the weight matrix U and the precoding matrix P, as well as the channel between the network device and the terminal device, is different.

[0128] For example, the precoding matrix P mentioned above is or In other words, the correlation between the reference signal, the weight matrix U, and the channel between the network device and the terminal device is as follows: or Where H represents the channel between the network device and the terminal device, H H Let H represent the conjugate transpose, where α is a real number, 1 is an N1 / N2×1 dimensional vector of all ones, N1 is the number of receive ports of the terminal device, and N2 is the number of transmit ports of the terminal device. In this case, during the process of the network device determining the precoding matrix P based on the weight matrix U, the channel represented by H can be a downlink channel. The dimension of H can be N1×M, where M is the number of transmit ports of the network device.

[0129] It should be noted that network devices can determine the precoding matrix P used for reference signal precoding using the method given in the above example, or they can determine the precoding matrix P using other possible implementations. The relationships given in the above examples are not unique; these relationships can also be determined based on the actual application scenario. Furthermore, K given in the above examples can also refer to the number of receiving ports of the same terminal device, in which case k is the k-th receiving port of the terminal device.

[0130] Furthermore, in this embodiment, the weight matrix U of the terminal device can be at the RB level, subband level, or broadband level. Correspondingly, the power factor α can also be at the RB level, subband level, or broadband level. In this case, the signaling overhead caused by sending the power factor to the terminal device is less.

[0131] In the above process, during data transmission, the network device does not need to send the weight matrix U of the terminal device to the terminal device through additional signaling, thereby reducing the signaling overhead between the terminal device and the network device when transmitting data.

[0132] S402. The terminal device determines the estimation result of the weight matrix U based on the reference signal.

[0133] Optionally, after receiving the reference signal obtained based on the precoding matrix P sent by the network device, the terminal device can estimate the weight matrix U of the terminal device carried by the reference signal based on the reference signal, the reference signal and the weight matrix U, and the correlation between the channel between the network device and the terminal device, thereby obtaining the estimation result of the weight matrix U of the terminal device.

[0134] When the weight matrix U of the terminal device is either a detection matrix for detecting (downlink) data signals or a precoding matrix for precoding (uplink) data signals, the correlation between the weight matrix U, the precoding matrix P, and the channel between the network device and the terminal device differs. Therefore, before determining the estimation result of the weight matrix U, the network device may send third information to the terminal device. This third information indicates the correlation between the terminal device's reference signal and the weight matrix U. Based on the correlation indicated by the third information, the terminal device determines how it estimates the weight matrix U using the reference signal.

[0135] It should be noted that, in this second embodiment, the association relationship indicated by the third information is, for example, the association relationship given in the example of the previous step S401, that is, the association relationship between the reference signal and the weight matrix U and the channel between the network device and the terminal device is: or The terminal device then determines the estimation result of the weight matrix U using the following method. The method for determining the estimation result of the weight matrix U based on the reference signal in this embodiment is described below with reference to an example:

[0136] For example, the reference signal received by the terminal device can be represented as or y represents the reference signal received by the terminal device from the network device. Here, n represents additive noise. In other words, the reference signal received by the terminal device is... The product of α, or the reference signal received by the terminal device. The product of H and α, U is the weight matrix of the terminal device. For further explanation of H, P, and α, please refer to the example above. At this point, the terminal device can... or The weight matrix U of the terminal device is estimated to obtain the estimation result of the weight matrix U of the terminal device.

[0137] Optionally, prior to step S402, the network device may send second information to the terminal device, which is used to indicate α. For a description of the second and third information, please refer to Embodiment 1, which will not be repeated here.

[0138] It should be noted that the method by which the terminal device determines its weight matrix U based on the received reference signal is not limited to the method given in the example above. Furthermore, the terminal device can directly obtain the estimated result of the weight matrix U based on the received reference signal during data transmission. In other words, the network device does not need to send the terminal device's weight matrix U to the terminal device via additional signaling. Therefore, this process reduces the signaling overhead during data transmission between the terminal device and the network device.

[0139] S403. The terminal device precodes the data signal sent from the terminal device to the network device based on the estimation result of the weight matrix U.

[0140] Optionally, before the terminal device precodes the data signal sent to the network device, the terminal device also receives first information sent by the network device. This first information indicates that the estimation result of the terminal device's weight matrix U is used to precode the data signal sent by the terminal device to the network device. A description of the first information can be found in Embodiment 1 above, and will not be repeated here.

[0141] Specifically, the terminal device multiplies the estimated weight matrix U with the data signal it sends to the network device for precoding, obtaining the precoded data signal. Finally, the terminal device sends the precoded data signal to the network device.

[0142] It should be noted that the multiplication operation between the estimated result of the weight matrix U by the terminal device and the data signal sent by the terminal device to the network device can be left multiplication or right multiplication, and is not limited to matrix multiplication. It can also include element-wise multiplication, weighting, and other operations.

[0143] Finally, in Embodiment 2, since the reference signal is correlated with the weight matrix U and the channel between the network device and the terminal device, after receiving the reference signal obtained based on the precoding matrix P, the terminal device can determine the corresponding weight matrix U according to the reference signal, so that the terminal device can use the weight matrix U to precode the data signal. In other words, during data transmission, the network device does not need to send the terminal device's weight matrix U to the terminal device through additional signaling, thereby reducing the signaling overhead between the terminal device and the network device during data transmission.

[0144] Example 3

[0145] Since the first embodiment involves symbol-level precoding (SLP), the following is a description of symbol-level precoding:

[0146] Symbol-level precoding (SLP) relies on the constellation diagram of the data signal modulation; therefore, a brief description of the constellation diagram is given first. Typically, data signals can be expressed in complex form, thus digital signals can be mapped onto the complex plane. Mapping the digital signals onto the complex plane yields the constellation diagram, which can intuitively represent the relationships between data signals and can be used to determine the bit error rate (BER) of the modulation scheme.

[0147] For example, as Figure 6 Taking a 16QAM constellation diagram of quadrature amplitude modulation (QAM) as an example, the horizontal axis of this constellation diagram represents the size of the real part of each constellation point, and the vertical axis represents the size of the imaginary part. This constellation diagram includes 16 constellation points: A1-A4, B1-B4, C1-C4, and D1-D4. The decision regions for both the real and imaginary parts of constellation points A1-A4 are bounded; the decision regions for the real parts of constellation points B1-B4 are unbounded but bounded; the decision regions for the imaginary parts of constellation points C1-C4 are bounded but unbounded; and the decision regions for both the real and imaginary parts of constellation points D1-D4 are unbounded.

[0148] In Symbol-Level Precoding (SLP), the real and imaginary parts of all constellation points with bounded decision domains in the data signal are amplified by the same factor 't', while the amplification factors (i.e., spread factors) of the real and imaginary parts of all constellation points without bounded decision domains are greater than 't'. This allows the constellation diagram formed by all data signals received by the terminal device to be expanded as a whole. For example, the constellation diagram mapped from the data signals received by the terminal device might look like this: Figure 7 As shown in (a), the received signal-to-noise ratio (SNR) of all data signals received by the terminal device is relatively high. However, to ensure that the terminal device can correctly demodulate the received data signals, the network device needs to send the spread coefficient of each data signal to the terminal device through additional signaling. Since the data signal is at the RE (resource element) level, the signaling overhead during data transmission between the terminal device and the network device is very large. To solve the above problem, in this embodiment, a symbol-level precoding scheme is proposed that can fix the spread coefficients of the real and imaginary parts of the constellation points with boundaries in the decision domain to 1. In this case, the network device does not need to send the spread coefficients of the constellation points, and the terminal device can also perform correct demodulation, thereby reducing the signaling overhead during data transmission between the terminal device and the network device.

[0149] The following example illustrates the process by which network devices in a MIMO system determine the precoding matrix W used for symbol-level precoding (SLP) and the spread coefficients t of the constellation points corresponding to the data signal, based on the downlink channel:

[0150] For example, a network device is configured with N transmit ports, capable of sending streaming data to K terminal devices (taking one streaming data stream per terminal device as an example). Each terminal device is configured with U receive ports. Let W be the precoding matrix W of the network device's data signal. The constellation point vector (corresponding to the data signal) sent by the network device is The downlink channel from the network device to the kth terminal device is The detection matrix of the kth terminal device is: The data signal received by the k-th terminal device is Where n is a normally distributed additive white Gaussian noise vector, i.e. σ 2 This represents the noise power distribution.

[0151] Network devices can be designed according to the following symbol-level precoding SLP design principles, namely...

[0152]

[0153] stC1.

[0154] C2.

[0155] C3.

[0156] C4.t≥1

[0157] C5.

[0158] Determine the precoding matrix W and t for the symbol-level precoding SLP. Wherein, This represents the equivalent downlink channel containing the detection matrix of the terminal device. s in k This represents the k-th element of the constellation point vector s sent by the network device, i.e., the constellation point mapped to the data signal sent by the network device to the k-th terminal device. middle, and They represent s respectively k The expansion coefficient of the real part and s k The expansion coefficient of the imaginary part. Let C1 represent the set {1, 2, ..., K}. C1 represents the data signal received by the k-th terminal device after superimposing the interference data and the data signal s after expanding its real and imaginary parts. k same. Let represent the set of expansion coefficients of the real or imaginary parts of all constellation points in s whose decision domains are unbounded. express The m-th expansion coefficient in the middle, Let represent the set of expansion coefficients of the real and imaginary parts of all constellation points in s whose decision domain has boundaries. express The nth expansion coefficient in the equation. For example, if s contains three elements, they are: Figure 6 The three constellation points A1, B1, and D1 in the first quadrant shown represent the sets of real and imaginary parts of the decision domain that are unbounded. The set of real and imaginary parts of the decision domain with boundaries is p0 represents the transmit power of the network device.

[0159] C1 represents the superposition of the data signal and the interference signal received by the k-th terminal device, which is exactly equal to the data signal after the real and imaginary parts are expanded; C2 represents the expansion coefficient of the real or imaginary part of the constellation point that makes all decision domains unbounded. (The elements in the middle) are greater than or equal to t; C3 represents the expansion coefficient of the real or imaginary part of the constellation points that make all decision domains bounded. (element in C3) equals 1; C4 indicates that t in C3 satisfies t>=1; C5 indicates that the transmit power of the network device is limited to meet the power limit condition.

[0160] It should be noted that, W and t can be obtained by using classical convex optimization algorithms such as the Lagrange multiplier method.

[0161] For example, according to Solve the problem. Where H = [h1, h2, ..., h K ] represents the equivalent downlink channel of K terminal devices that transmit data with the network device. I K Describes a K×K dimensional identity matrix. We will belong to Ω Extract the elements to form a vector Ω belongs to Extract the elements to form a vector Then it can be determined F is the sorting matrix. Where, and Furthermore, u can be solved by solving an optimization problem, i.e.

[0162]

[0163] stμ m ≥0

[0164] It is found that the solution methods include the search method and the Lagrange multiplier method.

[0165] For example, by fixing the expansion coefficients of the real and imaginary parts of the constellation points with boundaries in the decision domain to 1, and after determining the precoding matrix W used by the network device for data signal precoding through the above process, the network device sends the data signal precoded using the precoding matrix W to the terminal device, which can yield, for example... Figure 7 The constellation diagram shown in (b).

[0166] For example, with Figure 6 Taking 16QAM as an example, combined with Figure 6 , Figure 7 (a) and Figure 7 As can be seen from (b), in Figure 7 When the network device corresponding to (b) adopts the above symbol-level precoding scheme, the constellation points with boundaries in the decision domain of the data signal received by the terminal device are not expanded outward, and the positions of these constellation points remain unchanged. In other words, the terminal device can further reduce the signaling overhead in the data transmission process between the terminal device and the network device while correctly demodulating the data signal.

[0167] In summary, the symbol-level precoding scheme that fixes the spread coefficients of the real and imaginary parts of the constellation points with boundaries in the decision domain to 1 allows the terminal device to perform correct demodulation even when the network device does not need to send the spread coefficients of the constellation points, thereby reducing the signaling overhead when the terminal device and the network device transmit data.

[0168] The above mainly describes the solutions of the embodiments of this application from the perspective of interaction between various network elements. It is understood that each network element, such as access network equipment and terminals, includes corresponding hardware structures and / or software modules to perform the above functions in order to achieve them. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art 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.

[0169] This application embodiment can divide access network devices and terminals into functional units according to the above method examples. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0170] When dividing each function into modules according to its corresponding function. Figure 8 A schematic diagram of a possible structure of a communication device is shown. The communication device includes a receiving unit 801 and an estimation unit 802. Of course, the communication device may also include other modules, or it may include fewer modules. Optionally, the communication device further includes a signal detection unit 803 and a precoding unit 804. Optionally, the communication device further includes a transmitting unit 805, a storage unit 806, etc. Figure 8 The structural diagram shown can be used to illustrate the structure of a terminal device.

[0171] when Figure 8 When the schematic diagram shown illustrates the structure of the terminal device involved in the above embodiments, the estimation unit 802, signal detection unit 803, and precoding unit 804 are used to control and manage the actions of the terminal device. For example, the estimation unit 802 is used to support the terminal device in performing... Figure 3 S302 in the middle, Figure 4In S402, and / or other processes described in the embodiments of this application, the terminal device performs actions. The signal detection unit 803 is used to support the terminal device in performing... Figure 3 S303 in the above, and / or other actions performed by the access network device in the processes described in the embodiments of this application. The precoding unit 804 is used to support the terminal device in performing... Figure 4 The actions performed by the access network device in S403 and / or other processes described in the embodiments of this application. The estimation unit 802, signal detection unit 803, and precoding unit 804 can communicate with other network entities, such as with network devices in a communication system, through the receiving unit 801 and transmitting unit 805. The storage unit 806 is used to store the program code and data of the terminal device.

[0172] Figure 8 When the structural diagram shown is used to illustrate the structure of the terminal device involved in the above embodiments, the communication device can be a device or a chip within a device.

[0173] When dividing each function into modules according to its corresponding function. Figure 9 A schematic diagram of a possible structure of a communication device is shown. The communication device includes a transmitting unit 901. Of course, the communication device may also include other modules, or it may include fewer modules. Optionally, the communication device may also include a receiving unit 902, a processing unit 903, a storage unit 904, etc. Figure 9 The structural diagram shown can be used to illustrate the structure of network devices.

[0174] when Figure 9 The schematic diagram shown illustrates the structure of the network device involved in the above embodiments. The processing unit 903 is used to control and manage the actions of the network device. The processing unit 903 supports the network device in performing the actions described in the embodiments of this application. The processing unit 903 can communicate with other network entities through the receiving unit 902 and the sending unit 901, for example, communicating with terminal devices in a communication system. The storage unit 904 is used to store the program code and data of the network device.

[0175] Figure 9 When the schematic diagram shown is used to illustrate the structure of the network device involved in the above embodiments, the communication device can be a device or a chip within a device.

[0176] Figure 8 and Figure 9If the integrated units in the process are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. Storage media for storing computer software products include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0177] Figure 8 or Figure 9 The unit in the process can also be called a module; for example, the receiving unit can be called a receiving module.

[0178] Figure 10 This is a schematic diagram of the hardware structure of the communication device provided in an embodiment of this application. The communication device includes one or more processors 1001 and a communication interface 1003.

[0179] Optionally, the communication device further includes a memory 1004 coupled to the processor 1001. The memory 1004 may include ROM and RAM and provides operation instructions and data to the processor 1001. A portion of the memory 1004 may also include non-volatile random access memory (NVRAM).

[0180] In this embodiment of the application, the communication device executes the corresponding operation by calling the operation instructions stored in the memory 1004 (the operation instructions may be stored in the operating system).

[0181] The processor 1001 can also be called a central processing unit (CPU).

[0182] The processor 1001, communication interface 1003, and memory 1004 are coupled together via a communication bus 1002. This communication bus 1002 may include, in addition to a data bus, a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 10 The general labeled all buses as communication bus 1002.

[0183] The methods disclosed in the embodiments of this application can be applied to or implemented by the processor 1001. The processor 1001 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware or by instructions in the form of software in the processor 1001. The processor 1001 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software modules may be located in RAM, flash memory, ROM, programmable read-only memory or electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 1004. Processor 1001 reads the information in memory 1004 and, in conjunction with its hardware, completes the steps of the above method.

[0184] For example, Figure 10 The structural diagram shown can be used to illustrate the structure of the communication device involved in the above embodiments, and specifically to illustrate the structure of terminal equipment and network equipment.

[0185] when Figure 10 The schematic diagram shown illustrates the structure of the terminal device involved in the above embodiments. The processor 1001 is used to control and manage the actions of the network device. For example, the processor 1001 is used to support the terminal device in performing... Figure 3 S302 and S303 in the middle, Figure 4 The actions performed by the terminal device in processes S402, S403, and / or other processes described in the embodiments of this application. The processor 1001 can communicate with other network entities via the communication interface 1003, for example, with... Figure 3 The network devices shown communicate with each other. Memory 1004 is used to store program code and data of the terminal devices.

[0186] when Figure 10The schematic diagram shown illustrates the structure of the network device involved in the above embodiments. The processor 1001 is used to control and manage the actions of the terminal. The processor 1001 supports the network device in performing all the actions described in the embodiments of this application. The processor 1001 can communicate with other network entities through the communication interface 1003, for example, with... Figure 3 or Figure 4 The terminal devices shown communicate with each other. Memory 1004 is used to store the program code and data of the network devices.

[0187] The communication unit or communication interface described above can be an interface circuit or communication interface of the device, used to receive signals from other devices. For example, when the device is implemented as a chip, the communication unit or communication interface is an interface circuit or communication interface used by the chip to receive or send signals from other chips or devices.

[0188] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented using software programs, they can be implemented, in whole or in part, in the form of a computer program product. For example, instructions stored in memory for execution by a processor can be implemented in the form of a computer program product. The computer program product can be pre-written into memory or downloaded and installed in memory as software. 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 flow or function according to the embodiments of this application is 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, 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 store 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., DVDs), or semiconductor media (e.g., solid-state disks, SSDs), etc.

[0189] Optionally, embodiments of this application also provide a computer-readable storage medium storing computer instructions; when the computer-readable storage medium is run on a computer, the computer executes the communication method provided in embodiments of this application.

[0190] This application also provides a computer program product containing computer instructions, which, when run on a computer, enables the computer to execute the communication method provided in this application.

[0191] This application also provides a chip, which includes a processor and an interface. The processor is coupled to a memory through the interface. When the processor executes a computer program or instruction in the memory, the communication method provided in this application is executed.

[0192] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0193] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0194] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of the claims and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A communication method characterized by comprising: The method comprises: The terminal device receives a reference signal sent by the network device, the reference signal has an association relationship with a weight matrix U and a channel between the network device and the terminal device; The number of rows or columns of the weight matrix U is N, where N is a positive integer less than or equal to the number of receiving ports of the terminal device; The terminal device determines an estimation result of the weight matrix U according to the reference signal; The estimation result of the weight matrix U is used for the terminal device to perform signal detection on a data signal received by the terminal device from the network device; or the estimation result of the weight matrix U is used for the terminal device to perform precoding on a data signal sent by the terminal device to the network device; The reference signal has an association relationship with the weight matrix U and the channel between the network device and the terminal device, specifically comprising: The reference signal is determined by a matrix P = aH H (HH H ) -1 U is determined; wherein the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, and a is a real number; or, The reference signal is determined by a matrix or determining; wherein the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, a is a real number, 1 is an N1 / N2×1-dimensional all-1 vector, N1 is a receiving port number of the terminal device, and N2 is a transmitting port number of the terminal device. The α has an association relationship with the transmission power of the network device.

2. The communication method according to claim 1, characterized by, The estimation result of the weight matrix U is used for the terminal device to perform signal detection on a data signal received by the terminal device from the network device, specifically comprising: The terminal device multiplies the estimation result of the weight matrix U with the data signal received from the network device.

3. The communication method according to claim 1, wherein, The estimation result of the weight matrix U is used for the terminal device to perform precoding on a data signal sent by the terminal device to the network device, specifically comprising: The terminal device multiplies the estimation result of the weight matrix U with the data signal sent to the network device.

4. The communication method according to any one of claims 1-3, characterized by, The method further comprises: The terminal device receives first information sent by the network device; The first information is used to indicate that the estimation result of the weight matrix U of the terminal device is used for the terminal device to perform signal detection on a data signal received by the terminal device from the network device.

5. The communication method according to any one of claims 1-3, wherein, The method further comprises: The terminal device receives first information sent by the network device; The first information is used to indicate that the estimation result of the weight matrix U of the terminal device is used for the terminal device to perform precoding on a data signal sent by the terminal device to the network device.

6. The communication method of claim 1, wherein, The method further comprises: The terminal device receives second information sent by the network device, and the second information is used to indicate the α.

7. The communication method according to any one of claims 1-6, wherein, The method further comprises: The terminal device receives third information sent by the network device, and the third information is used to indicate the association relationship between the reference signal and the weight matrix U of the terminal device.

8. A communication method characterized by comprising: The method comprises: The network device sends a reference signal to a terminal device, the reference signal has an association relationship with a weight matrix U and a channel between the network device and the terminal device; The number of rows or columns of the weight matrix U is N, where N is a positive integer less than or equal to the number of receiving ports of the terminal device; The reference signal is used by the terminal device to determine an estimation result of the weight matrix U; the estimation result of the weight matrix U is used by the terminal device to perform signal detection on a data signal received by the terminal device from the network device, or the estimation result of the weight matrix U is used by the terminal device to perform precoding on a data signal transmitted by the terminal device to the network device; The reference signal has an association relationship with the weight matrix U and a channel between the network device and the terminal device, and specifically includes: The reference signal is determined by a matrix P = aH H (HH H ) -1 U is determined; wherein the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, and a is a real number; or, The reference signal is determined by a matrix or determines; wherein, the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, the a is a real number, 1 is an N1 / N2×1-dimensional all-1 vector, the N1 is a receiving port number of the terminal device, and the N2 is a transmitting port number of the terminal device. The α has an association relationship with a transmission power of the network device.

9. The communication method according to claim 8, wherein, The method further includes: The network device sends first information to the terminal device; The first information is used to indicate that the estimation result of the weight matrix U of the terminal device is used by the terminal device to perform signal detection on a data signal received by the terminal device from the network device.

10. The communication method according to claim 8, wherein, The method further includes: The network device sends first information to the terminal device; The first information is used to indicate that the estimation result of the weight matrix U of the terminal device is used by the terminal device to perform precoding on a data signal transmitted by the terminal device to the network device.

11. The communication method according to claim 8, wherein, The method further includes: The network device sends second information to the terminal device, and the second information is used to indicate the α.

12. The communication method according to any one of claims 8-11, characterized by, The method further includes: The network device sends third information to the terminal device; The third information is used to indicate the association relationship between the reference signal and the weight matrix U of the terminal device.

13. A communications device, characterized by The apparatus includes a receiving unit and an estimation unit: The receiving unit is configured to receive a reference signal sent by a network device, the reference signal having an association relationship with a weight matrix U and a channel between the network device and a terminal device; The number of rows or columns of the weight matrix U is N, where N is a positive integer less than or equal to the number of receiving ports of the terminal device; The estimation unit is configured to determine an estimation result of the weight matrix U according to the reference signal; The estimation result of the weight matrix U is used by the terminal device to perform signal detection on a data signal received by the terminal device from the network device, or the estimation result of the weight matrix U is used by the terminal device to perform precoding on a data signal transmitted by the terminal device to the network device; The reference signal has an association relationship with the weight matrix U and a channel between the network device and the terminal device, and specifically includes: The reference signal is given by matrix P = αH H (HH H ) -1 U is determined; where H represents the channel between the network device and the terminal device, H H This represents the conjugate transpose of H, where α is a real number; or, The reference signal is determined by a matrix or ; wherein, the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, a is a real number, 1 is an N1 / N2×1-dimensional all-1 vector, the N1 is a receiving port number of the terminal device, and the N2 is a transmitting port number of the terminal device. The α has an association relationship with a transmission power of the network device.

14. The communication apparatus according to claim 13, wherein The apparatus further includes a signal detection unit: The signal detection unit is configured to multiply the estimation result of the weight matrix U with a data signal received by the terminal device from the network device.

15. The communication apparatus according to claim 13, wherein The apparatus further includes a precoding unit: The precoding unit is configured to multiply the estimation result of the weight matrix U with a data signal transmitted by the terminal device to the network device.

16. The communication apparatus according to any one of claims 13-15, wherein, The receiving unit is further configured to receive first information sent by the network device; The first information is used for indicating that the estimation result of the weight matrix U of the terminal device is used for signal detection on a data signal received by the terminal device from the network device.

17. The communication apparatus according to any one of claims 13-15, wherein, The receiving unit is further configured to receive first information sent by the network device. The first information is used for indicating that the estimation result of the weight matrix U of the terminal device is used for precoding on a data signal sent by the terminal device to the network device.

18. The communication apparatus according to claim 13, wherein The receiving unit is further configured to receive second information sent by the network device, the second information being used for indicating the α.

19. The communication apparatus according to any one of claims 13-18, wherein, The receiving unit is further configured to receive third information sent by the network device, the third information being used for indicating the association between the reference signal and the weight matrix U of the terminal device.

20. A communications device, characterized by The apparatus comprises a sending unit: The sending unit is configured to send a reference signal to a terminal device, the reference signal having an association with a weight matrix U and a channel between a network device and the terminal device. The number of rows or columns of the weight matrix U is N, where N is a positive integer less than or equal to the number of receiving ports of the terminal device. The reference signal is used for the terminal device to determine an estimation result of the weight matrix U, and the estimation result of the weight matrix U is used for the terminal device to perform signal detection on a data signal received by the terminal device from the network device, or the estimation result of the weight matrix U is used for the terminal device to perform precoding on a data signal sent by the terminal device to the network device. The reference signal has an association with the weight matrix U and the channel between the network device and the terminal device, and specifically includes: The reference signal is determined by a matrix P = aH H (HH H ) -1 U is determined; wherein the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, and a is a real number; or, The reference signal is determined by a matrix or ; wherein, the H represents a channel between the network device and the terminal device, the H H represents a conjugate transpose of the H, the a is a real number, 1 is an N1 / N2×1-dimensional all-1 vector, the N1 is a receiving port number of the terminal device, and the N2 is a transmitting port number of the terminal device. The α has an association with the transmission power of the network device.

21. The communication apparatus according to claim 20, wherein, The sending unit is further configured to send first information to the terminal device. The first information is used for indicating that the estimation result of the weight matrix U of the terminal device is used for signal detection on a data signal received by the terminal device from the network device.

22. The communication apparatus according to claim 20, wherein, The sending unit is further configured to send first information to the terminal device. The first information is used for indicating that the estimation result of the weight matrix U of the terminal device is used for precoding on a data signal sent by the terminal device to the network device.

23. The communication apparatus according to claim 20, wherein, The sending unit is further configured to send second information to the terminal device, the second information being used for indicating the α.

24. The communication apparatus according to any one of claims 20-23, wherein, The sending unit is further configured to send third information to the terminal device. The third information is used for indicating the association between the reference signal and the weight matrix U of the terminal device.

25. A communications device, characterized by The communication apparatus comprises a processor and a memory; The memory is coupled to the processor, and is configured to store computer instructions, when the processor executes the computer instructions stored in the memory, the communication apparatus performs the communication method in any one of claims 1-7, or the communication apparatus performs the communication method in any one of claims 8-12.

26. A computer-readable storage medium, characterized in that, comprising instructions which, when executed on a computer, cause the computer to carry out the communication method of any one of claims 1 to 7, or the communication method of any one of claims 8 to 12.

27. A computer program product, characterised in that, comprising instructions which, when executed on a computer, cause the computer to carry out the communication method of any one of claims 1 to 7, or the communication method of any one of claims 8 to 12.

28. A chip, characterized by comprising: a processor and an interface, the processor being coupled to a memory through the interface, when the processor executes a computer program or instructions in the memory, causes the communication method of any one of claims 1 to 7 to be executed, or the communication method of any one of claims 8 to 12 to be executed.

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