Signal transmission method and related apparatus

Abstract

The application provides a signal transmission method and related devices. The signal transmission method comprises: a terminal device receiving a first received signal; the first received signal is transmitted to the terminal device through a corresponding downlink channel of the terminal device after a first reference signal is precoded according to a first channel matrix; the first channel matrix is obtained according to a second channel matrix; the number of rows and / or columns of the first channel matrix is less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in MIMO transmission; and the second channel matrix is a channel matrix of the corresponding downlink channel of the one or more terminal devices. The terminal device obtains an equivalent channel coefficient corresponding to the terminal device according to the first received signal.

Description

Technical Field

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

[0002] 5G communication systems have higher requirements for system capacity, spectrum efficiency, etc. In 5G communication systems, massive multiple input multiple output (MIMO) plays a crucial role in the system's spectrum efficiency.

[0003] When using MIMO technology, network devices need to perform precoding when sending data to terminal devices via multiple antenna ports. Given known channel conditions, network devices can preprocess the transmitted signal using a precoding matrix that matches the channel, adapting the precoded signal to the channel and improving transmission performance. In specific implementations, the transmitting device can also perform precoding using other methods. For example, when channel information is unavailable, a precoding matrix or weighted processing method can be used for precoding.

[0004] In related technologies, network equipment can send a demodulation reference signal (DMRS) to a terminal device. The DMRS and the data signal undergo the same precoding processing based on the same precoding matrix. The terminal device's receiver estimates the equivalent channel matrix or equivalent channel coefficients using the DMRS, and then estimates the received data signal based on this equivalent channel matrix or equivalent channel coefficients.

[0005] When the THP algorithm performs precoding in a MIMO scenario, it uses the feedback matrix B to perform precoding to eliminate interference. B = GR H , R is the conjugate transposed matrix H of the channel matrix H for all users H The matrix G is a diagonal matrix, and its main diagonal elements are the reciprocals of the main diagonal elements of the R matrix. The dimension of the user's complete channel matrix H is For large-scale antennas, the number of transmitting antennas is usually large, such as 64T. In addition, when the number of paired users is large, The value of is also large. Therefore, the QR decomposition complexity of the channel matrix H is high. Therefore, in the THP precoding process, the matrix calculation dimension is large and the complexity is high. Summary of the Invention

[0006] The present application provides a signal transmission method and related devices, which can reduce the computational difficulty of channel matrix decomposition, reduce the complexity of precoding calculations, and improve transmission performance.

[0007] In a first aspect, the present application provides a signal transmission method, comprising: a terminal device receives a first received signal; the first received signal is sent to the terminal device via a downlink channel corresponding to the terminal device after precoding a first reference signal according to a first channel matrix, the first channel matrix is ​​obtained according to a second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in MIMO transmission, and the second channel matrix is ​​the channel matrix of the downlink channel corresponding to the one or more terminal devices; the terminal device obtains an equivalent channel coefficient corresponding to the terminal device based on the first received signal. The equivalent channel coefficient can be used to detect data signals.

[0008] According to the technical solution of the present application, the first received signal is sent to the terminal device via the downlink channel corresponding to the terminal device after the first reference signal is precoded according to the first channel matrix. The first channel matrix is ​​obtained according to the second channel matrix. The number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, thereby reducing the difficulty of matrix calculation during the THP precoding process and making the THP precoding calculation simpler.

[0009] It should be understood that the precoding in the present application may be THP precoding or other precoding techniques. For example, the precoding may be, but is not limited to, symbol level precoding (SLP), vector perturbation (VP) precoding, zero-forcing (ZF) precoding, etc.

[0010] In some possible implementations, the first channel matrix It is obtained by processing the second channel matrix according to the receiving weight matrix W and the weight matrix V.

[0011] In this application, the weight matrix may be an outer weight matrix.

[0012] In some implementations, the number of rows of the weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of the one or more terminal devices participating in the MIMO transmission.

[0013] Optionally, the first channel matrix Second channel matrix The first channel matrix The number of rows is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, or the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0014] Optionally, the first channel matrix Second channel matrix The first channel matrix The number of columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, or the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0015] For example, the number of rows of the weight matrix V is the sum of the number of transmission streams of the one or more terminal devices, and / or the number of columns of the weight matrix is ​​the sum of the number of transmission streams of the multiple terminal devices. In this way, by properly designing the weight matrix V and the receiving weight matrix W, the first channel matrix The number of rows and columns of are both the sum L of the total number of transmission streams of one or more terminal devices participating in MIMO transmission, which solves the problem of matrix dimension mismatch caused by the sum L of the total number of transmission streams of n terminal devices participating in MIMO transmission being less than the sum of the total number of receiving antennas of multiple terminal devices.

[0016] In some embodiments, the first channel matrix W is a receive weight matrix, V is a weight matrix, and H is the second channel matrix. The number of rows of the receive weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receive antennas of the one or more terminal devices participating in the MIMO transmission. In this way, the second channel matrix is ​​subjected to dimensionality reduction processing using the receive weight matrix and the weight matrix to obtain a first matrix with a dimension less than or equal to that of the second channel matrix, thereby reducing the computational difficulty of channel matrix decomposition.

[0017] Optionally, the receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; and the method further includes:

[0018] The terminal device receives a second reception signal;

[0019] The terminal device obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes:

[0020] The terminal device determines, according to the second received signal, an estimated receiving weight submatrix corresponding to the receiving weight submatrix;

[0021] The terminal device obtains an equivalent channel coefficient corresponding to the terminal device based on the estimated receiving weight matrix and the first received signal. For example, the terminal device may multiply the estimated receiving weight matrix by the first received signal to obtain a third received signal, and then perform channel estimation based on the third received signal and the first reference signal.

[0022] In this way, the terminal device determines the estimated receiving weight matrix corresponding to the terminal device based on the receiver type and the second received signal corresponding to the second reference signal. In the present application, when performing channel estimation, the network device sends another reference signal (second reference signal) in addition to the reference signal used for direct channel estimation. This scheme of implicitly indicating the receiving weight matrix through the second reference signal can avoid signaling notification of the receiving weight matrix, reduce downlink signaling overhead, and avoid performance loss caused by quantization during notification, compared to the scheme of direct indication through signaling.

[0023] Optionally, the weight matrix includes a weight submatrix corresponding to the terminal device, and the second received signal is transmitted to the terminal device via a downlink channel corresponding to the terminal device after the network device precodes a second reference signal according to the weight submatrix. In this way, the terminal device can estimate the estimated receiving weight submatrix corresponding to the terminal device based on the second reference signal.

[0024] Optionally, the receiving weight matrix corresponding to the terminal device is obtained based on the channel matrix and weight matrix corresponding to the terminal device.

[0025] In some other possible implementations, the first channel matrix It is obtained by processing the second channel matrix according to the receiving weight matrix W.

[0026] The first channel matrix Second channel matrix The number of rows in the receiving weight matrix W is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, that is, the first channel matrix The number of rows is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0027] Alternatively, the first channel matrix Second channel matrix The number of columns of the receiving weight matrix W is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, that is, a channel matrix The number of columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0028] In this way, the second channel matrix is ​​subjected to dimensionality reduction processing by the receiving weight matrix and the weight value matrix to obtain a first matrix with a dimension smaller than or equal to that of the second channel matrix, thereby reducing the computational difficulty of channel matrix decomposition.

[0029] Optionally, the number of rows of the receiving weight matrix is ​​the sum of the number of transmission streams of the plurality of terminal devices. In this way, by properly designing the receiving weight matrix W, the first channel matrix The number of rows is the sum L of the total number of transmission streams of one or more terminal devices participating in MIMO transmission, which solves the problem of matrix dimension mismatch caused by the sum L of the total number of transmission streams of n terminal devices participating in MIMO transmission being less than the sum of the total number of receiving antennas of multiple terminal devices.

[0030] Specifically, the receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; and the method further includes:

[0031] The terminal device receives a second reception signal;

[0032] The terminal device obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes:

[0033] The terminal device determines, according to the second received signal, an estimated receiving weight submatrix corresponding to the receiving weight submatrix;

[0034] The terminal device obtains the equivalent channel coefficient corresponding to the terminal device based on the estimated receiving weight matrix and the first received signal.

[0035] In this way, the terminal device determines the estimated receiving weight matrix corresponding to the terminal device based on the receiver type and the second received signal corresponding to the second reference signal. In the present application, when performing channel estimation, in addition to the reference signal used for direct channel estimation, another reference signal (second reference signal) is also sent. This scheme of implicitly indicating the receiving weight matrix through the second reference signal, compared to the scheme of direct indication through signaling, can avoid signaling notification of the receiving weight matrix, reduce downlink signaling overhead, and avoid performance loss caused by quantization during notification.

[0036] In some embodiments, the method further includes: the terminal device receiving a first received data signal, the first received data signal being transmitted to the terminal device via a downlink channel corresponding to the terminal device after the network device precodes the transmit data signal according to the first channel matrix; and the terminal device detecting the first received data signal based on the estimated receive weight matrix and an equivalent channel coefficient corresponding to the terminal device. In this way, the terminal device can detect the received data signal based on the equivalent channel coefficient.

[0037] In certain embodiments, the terminal device detects the data signal based on the estimated receive weight matrix and the equivalent channel coefficient corresponding to the terminal device, including: the terminal device multiplies the first receive data signal by the estimated receive weight matrix to obtain a second receive data signal corresponding to the first receive data signal; and the terminal device obtains an estimate of the transmit data signal based on the second receive data signal and the equivalent channel coefficient corresponding to the terminal device. In this way, the network device processes the transmit data signal based on the receive weight matrix, and the terminal device processes the first receive data signal based on the receive weight matrix. Both the network device and the terminal device perform operations and processing based on the same receiver assumptions, ensuring matching calculations between the transmitter and receiver. This can avoid reporting or downlink notification of the detection weight matrix.

[0038] Optionally, the method further includes: the terminal device transmitting a receiver type of the terminal device, where the receiver type of the terminal device is used by the network device to determine the reception weight matrix. In this way, the network device can determine the reception weight submatrix corresponding to the terminal device based on the receiver type reported by the terminal device and according to a preset receiver or reception weight calculation method, thereby obtaining the first channel matrix.

[0039] In a second aspect, an embodiment of the present application also provides a signal transmission method for multiple-input multiple-output MIMO transmission, comprising: a network device precodes a first reference signal according to a first channel matrix to obtain a first transmit signal, the first channel matrix is ​​obtained according to a second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in the MIMO transmission, and the second channel matrix is ​​the channel matrix of the downlink channel of the one or more terminal devices; the network device sends the first transmit signal.

[0040] It should be understood that the first transmission signal is sent to one or more terminal devices participating in MIMO transmission. The one or more terminal devices receive their respective corresponding first reception signals in their respective downlink channels.

[0041] According to the technical solution of the present application, a network device precodes a first reference signal according to a first channel matrix, where the first channel matrix is ​​obtained according to a second channel matrix, and the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of n terminal devices participating in MIMO transmission, thereby reducing the difficulty of matrix calculation during THP precoding and making the THP precoding calculation simpler.

[0042] Optionally, the second channel matrix The first channel matrix The number of rows is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, or the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0043] Optionally, the second channel matrix The first channel matrix The number of columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, or the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0044] In some possible implementations, the first channel matrix W is a receive weight matrix, and V is a weight matrix. The number of rows of the receive weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receive antennas of the one or more terminal devices. In this way, the second channel matrix is ​​subjected to dimensionality reduction processing using the receive weight matrix and the weight matrix to obtain a first matrix having a dimension less than or equal to that of the second channel matrix, thereby reducing the computational difficulty of channel matrix decomposition.

[0045] Optionally, the number of rows of the receiving weight matrix is ​​the sum of the number of transmission streams of the one or more terminal devices, and / or the number of columns of the weight matrix is ​​the number of transmission streams of the one or more terminal devices. In this way, by properly designing the weight matrix V and the receiving weight matrix W, the first channel matrix The number of rows and columns of are both the sum L of the total number of transmission streams of one or more terminal devices participating in MIMO transmission, which solves the problem of matrix dimension mismatch caused by the sum L of the total number of transmission streams of n terminal devices participating in MIMO transmission being less than the sum of the total number of receiving antennas of multiple terminal devices.

[0046] In some embodiments, the weight matrix includes a weight submatrix corresponding to each of the one or more terminal devices, where the weight submatrix corresponding to each terminal device is determined based on the channel matrix of the downlink channel corresponding to the terminal device. The network device calculates the weight submatrix based solely on the channel matrix corresponding to each terminal device and does not rely on channel information of other users, eliminating the need for joint detection or notification of other users' channel state information.

[0047] Optionally, the receiving weight matrix corresponding to each terminal device is obtained according to the channel matrix and weight matrix corresponding to the terminal device.

[0048] In some possible implementations, the method further includes: the network device sends a second transmission signal, and each terminal device in the one or more terminal devices of the second transmission signal determines the estimated reception weight matrix corresponding to its own corresponding reception weight matrix. In this way, the terminal device can determine the estimated reception weight matrix corresponding to the terminal device based on the receiver type and the second reception signal corresponding to the second reference signal. In the present application, when performing channel estimation, the network device sends another reference signal (second reference signal) in addition to sending a reference signal for directly performing channel estimation. This scheme of implicitly indicating the reception weight matrix through the second reference signal can avoid signaling notification of the reception weight matrix, reduce downlink signaling overhead, and avoid performance loss caused by quantization during notification, compared to the scheme of direct indication through signaling.

[0049] Specifically, the second transmission signal is obtained by the network device precoding the second reference signal according to the weight sub-matrix. In this way, the terminal device can estimate the estimated receiving weight sub-matrix corresponding to the terminal device according to the second reference signal.

[0050] In some other possible implementations, the first channel matrix W is a receive weight matrix, and the number of rows in the receive weight matrix is ​​less than or equal to the sum of the number of receive antennas of the one or more terminal devices. In this way, the second channel matrix is ​​subjected to dimensionality reduction processing using the receive weight matrix and the weight matrix to obtain a first matrix with a dimension less than or equal to that of the second channel matrix, thereby reducing the computational difficulty of channel matrix decomposition.

[0051] In certain embodiments, the receiving weight matrix includes a receiving weight submatrix corresponding to each of the multiple terminal devices. The receiving weight submatrix corresponding to each terminal device is determined by the network device based on the receiver type of the terminal device. The network device calculates the receiving weight matrix without relying on channel information of other users and without requiring joint detection or notification of other users' channel state information. This allows the receiving terminal device to more simply estimate the estimated receiving weight submatrix corresponding to the receiving weight submatrix corresponding to the terminal device when detecting a signal, thereby reducing the processing complexity of the terminal device.

[0052] In certain embodiments, the method further includes: the network device precoding a transmit data signal based on the first channel matrix to obtain a precoded transmit data signal; and the network device transmitting the precoded transmit data signal. Thus, since the first transmit signal is encoded by encoding the first reference signal based on the first channel matrix, and the transmit data signal is also precoded based on the first channel matrix, the terminal device can obtain an equivalent channel coefficient corresponding to the terminal device based on the first received signal corresponding to the first transmit signal, and detect the received data signal corresponding to the transmit data signal based on the equivalent channel coefficient.

[0053] In a third aspect, an embodiment of the present application further provides a signal transmission device, comprising a receiving unit and a processing unit; the signal transmission device may be, for example, a terminal device, or the signal transmission device may be deployed in the terminal device; the receiving unit is used to receive a first received signal; the first received signal is sent to the terminal device via a downlink channel corresponding to the terminal device after precoding the first reference signal according to a first channel matrix, the first channel matrix is ​​obtained according to a second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in MIMO transmission, and the second channel matrix is ​​the channel matrix of the downlink channel corresponding to the one or more terminal devices; the processing unit is used to obtain the equivalent channel coefficient corresponding to the terminal device based on the first received signal.

[0054] According to the technical solution of the present application, the first received signal is sent to the terminal device via the downlink channel corresponding to the terminal device after the first reference signal is precoded according to the first channel matrix. The first channel matrix is ​​obtained according to the second channel matrix. The number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, thereby reducing the difficulty of matrix calculation during the THP precoding process and making the THP precoding calculation simpler.

[0055] In some embodiments, the first channel matrix W is the receiving weight matrix, V is the weight matrix, H is the second channel matrix, and the number of rows of the receiving weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in the MIMO transmission.

[0056] In some embodiments, the number of rows of the reception weight matrix is ​​the sum of the number of transmission streams of the one or more terminal devices, and / or the number of columns of the weight matrix is ​​the sum of the number of transmission streams of the multiple terminal devices.

[0057] In some embodiments, the receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; the receiving unit is further configured to receive a second receiving signal;

[0058] The processing unit is further configured to:

[0059] Obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes:

[0060] Determining an estimated receiving weight matrix corresponding to the receiving weight matrix according to the second received signal; and

[0061] An equivalent channel coefficient corresponding to the terminal device is obtained according to the estimated receiving weight matrix and the first received signal.

[0062] In some embodiments, the weight matrix includes a weight sub-matrix corresponding to the terminal device, and the second received signal is sent to the terminal device through the downlink channel corresponding to the terminal device after the network device precodes the second reference signal according to the weight sub-matrix.

[0063] Optionally, the receiving weight matrix corresponding to the terminal device is obtained based on the channel matrix and weight matrix corresponding to the terminal device.

[0064] In some embodiments, the first channel matrix W is a receiving weight matrix, and the number of rows of the receiving weight matrix is ​​less than the sum of the number of receiving antennas of the one or more terminal devices participating in the MIMO transmission.

[0065] In some embodiments, the number of rows of the reception weight matrix is ​​the sum of the numbers of transmission streams of the multiple terminal devices.

[0066] In some embodiments, the receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; the receiving unit is further configured to receive a second receiving signal;

[0067] The processing unit is also used to:

[0068] Obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes:

[0069] Determining an estimated receiving weight matrix corresponding to the receiving weight matrix according to the second received signal; and

[0070] An equivalent channel coefficient corresponding to the terminal device is obtained according to the estimated receiving weight matrix and the first received signal.

[0071] In some embodiments, the receiving unit is also used to receive a first received data signal, which is sent to the terminal device through the downlink channel corresponding to the terminal device after the network device pre-encodes the sent data signal according to the first channel matrix; the processing unit is also used to detect the first received data signal based on the estimated receiving weight matrix and the equivalent channel coefficient corresponding to the terminal device.

[0072] In some embodiments, in terms of detecting the data signal based on the estimated receiving weight matrix and the equivalent channel coefficient corresponding to the terminal device, the processing unit is specifically configured to:

[0073] Left-multiplying the first received data signal by the estimated receiving weight matrix to obtain a second received data signal corresponding to the first received data signal;

[0074] An estimation result of the transmitted data signal is obtained based on the equivalent channel coefficient corresponding to the second received data signal and the terminal device.

[0075] In some embodiments, the signal transmission apparatus further includes: a sending unit configured to send a receiver type of the terminal device, where the receiver type of the terminal device is used by a network device to determine the receiving weight matrix.

[0076] It should be understood that the technical effects and related supplementary explanations of each embodiment of the signal transmission method of the first aspect mentioned above are also applicable to the signal transmission device of the third aspect of this application, and will not be repeated here.

[0077] In fourth aspect, an embodiment of the present application also provides a signal transmission device for multiple-input multiple-output MIMO transmission, comprising a processing unit and a sending unit; the signal transmission device may be, for example, a network device, or the signal transmission device may be deployed in a network device; wherein the processing unit is used to precode a first reference signal according to a first channel matrix to obtain a first transmission signal, the first channel matrix is ​​obtained according to a second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in the MIMO transmission, and the second channel matrix is ​​the channel matrix of the downlink channel of the one or more terminal devices; the sending unit is used to send the first transmission signal.

[0078] According to the technical solution of the present application, a signal transmission device precodes a first reference signal according to a first channel matrix, the first channel matrix is ​​obtained according to a second channel matrix, and the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of n terminal devices participating in MIMO transmission, thereby reducing the difficulty of matrix calculation during THP precoding and making the THP precoding calculation simpler.

[0079] In some embodiments, the first channel matrix W is the receiving weight matrix, V is the weight matrix, and the number of rows of the receiving weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of the one or more terminal devices.

[0080] In some embodiments, the number of rows of the reception weight matrix is ​​the sum of the number of transmission streams of the one or more terminal devices, and / or the number of columns of the weight matrix is ​​the number of transmission streams of the one or more terminal devices.

[0081] In some embodiments, the weight matrix includes a weight sub-matrix corresponding to each terminal device among the one or more terminal devices, and the weight sub-matrix corresponding to each terminal device is determined based on a channel matrix of a downlink channel corresponding to the terminal device.

[0082] Optionally, the receiving weight matrix corresponding to each terminal device is obtained according to the channel matrix and weight matrix corresponding to the terminal device.

[0083] In some embodiments, the sending unit is further configured to send a second sending signal, where the second sending signal enables each of the one or more terminal devices to determine an estimated receiving weight matrix corresponding to its own receiving weight matrix.

[0084] In some implementations, the second transmit signal is obtained by the network device precoding a second reference signal according to the weight sub-matrix.

[0085] In some embodiments, the first channel matrix W is a receiving weight matrix, and the number of rows of the receiving weight matrix is ​​less than or equal to the sum of the number of receiving antennas of the one or more terminal devices.

[0086] In some embodiments, the receiving weight matrix includes a receiving weight sub-matrix corresponding to each terminal device among the multiple terminal devices, and the receiving weight sub-matrix corresponding to each terminal device is determined by the network device according to the receiver type of the terminal device.

[0087] In some embodiments, the processing unit is further configured to precode the transmit data signal according to the first channel matrix to obtain a precoded transmit data signal; and the transmitting unit is further configured to transmit the precoded transmit data signal.

[0088] It should be understood that the technical effects and related supplementary explanations of each embodiment of the signal transmission method of the second aspect mentioned above are also applicable to the signal transmission device of the fourth aspect of this application, and will not be repeated here.

[0089] In a fifth aspect, the present application provides a communication device, which is a terminal device or a network device, including a processor and a memory, the memory being used to store computer instructions, and the processor executing the computer program or instructions in the memory, so that the method of any embodiment of the above-mentioned first aspect or the above-mentioned second aspect is executed.

[0090] In a sixth aspect, the present application further provides a communication device, comprising a processor, a memory, and a transceiver, wherein the transceiver is configured to receive or transmit signals; the memory is configured to store program code; and the processor is configured to call the program code from the memory to execute the method of the first or second aspect. The memory is configured to store computer programs or instructions, and the processor is configured to call and execute the computer program or instructions from the memory. When the processor executes the computer program or instructions in the memory, the communication device executes any one of the implementations of the method of the first or second aspect described above.

[0091] Optionally, there are one or more processors and one or more memories.

[0092] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0093] Optionally, the transceiver may include a transmitter (transmitter) and a receiver (receiver).

[0094] In a seventh aspect, the present application provides an apparatus comprising a processor coupled to a memory, wherein when the processor executes a computer program or instruction in the memory, the method of any embodiment of the first aspect is performed. Optionally, the apparatus further comprises a memory. Optionally, the apparatus further comprises a communication interface coupled to the processor.

[0095] In one implementation, the apparatus is a terminal device. When the communication device is a terminal device, the communication interface may be a transceiver or an input / output interface. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0096] In another implementation, the device is a chip or a chip system. When the device is a chip or a chip system, the communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be embodied as a processing circuit or a logic circuit.

[0097] In an eighth aspect, the present application provides a communication device, comprising a processor and an interface circuit, the interface circuit being configured to receive code instructions and transmit them to the processor; the processor running the code instructions to execute the method in any possible implementation of the first aspect or the second aspect.

[0098] In a ninth aspect, the present application provides a system, which includes the above-mentioned terminal device and network device.

[0099] In the tenth aspect, the present application provides a computer program product, which includes: a computer program (also referred to as code, or instructions), which, when the computer program is run, enables the computer to execute the method in any possible implementation of the above-mentioned first aspect or the above-mentioned second aspect.

[0100] In the eleventh aspect, the present application provides a computer-readable storage medium, which stores a computer program (also referred to as code, or instructions) which, when run on a computer, enables the computer to execute the method in any possible implementation of the above-mentioned first aspect or the above-mentioned second aspect.

[0101] In the twelfth aspect, the present application also provides a chip, comprising: a processor and an interface, for executing a computer program or instruction stored in a memory, and executing the method in any possible implementation of the above-mentioned first aspect or the above-mentioned second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments.

[0103] Figure 1 A network architecture diagram of a network system involved in an embodiment of the present application;

[0104] Figure 2A This is a schematic structural diagram of a communication device according to an embodiment of the present application;

[0105] Figure 2B This is a schematic diagram of the structure of the chip according to the embodiment of the present application;

[0106] Figure 3A Schematic diagram of the scene pre-encoded for THP;

[0107] Figure 3B Schematic diagram of the THP precoding process;

[0108] Figure 4 A schematic diagram of a flow chart of a signal transmission method according to an embodiment of the present application;

[0109] Figure 5A This is another schematic flow chart of the signal transmission method according to an embodiment of the present application;

[0110] Figure 5B This is another schematic flow chart of the signal transmission method according to an embodiment of the present application;

[0111] Figure 5C A schematic diagram of a scenario involved in the signal transmission method according to an embodiment of the present application;

[0112] Figure 6 This is another schematic flow chart of the signal transmission method according to an embodiment of the present application;

[0113] Figure 7 This is another schematic flow chart of the signal transmission method according to an embodiment of the present application;

[0114] Figure 8 This is a schematic structural diagram of a signal transmission device according to an embodiment of the present application;

[0115] Figure 9 FIG. 2 is another structural diagram of the signal transmission device according to an embodiment of the present application. DETAILED DESCRIPTION

[0116] The technical solution in this application will be described below with reference to the accompanying drawings.

[0117] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), world-wide interoperability for microwave access (WiMAX) communication system, 5G mobile communication system or new radio access technology (NR). Among them, the 5G mobile communication system may include non-standalone (NSA) and / or standalone (SA).

[0118] The technical solution provided in this application can also be applied to machine type communication (MTC), long term evolution technology for machine-to-machine communication (LTE-M), device-to-device (D2D) network, machine-to-machine (M2M) network, Internet of Things (IoT) network or other networks. Among them, the IoT network may include, for example, the Internet of Vehicles. Among them, the communication mode in the Internet of Vehicles system is collectively referred to as vehicle to other devices (vehicle to X, V2X, X can represent anything), for example, the V2X may include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, etc.

[0119] The technical solution provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, etc. This application does not limit this.

[0120] In the embodiment of the present application, the network device can be any device with wireless transceiver function. The device includes but is not limited to: an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB, or a homeNode B, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WiFi) system, a wireless relay node, a wireless backhaul node, a transmission point (TP) or a transmission and reception point (TRP), etc. It can also be a gNB in ​​a 5G, such as NR, system, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU), etc.

[0121] In some deployments, a gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC), medium access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that a network device can be a device that includes one or more of a CU node, a DU node, or an AAU node. In addition, the CU may be classified as a network device in an access network (radio access network, RAN), or may be classified as a network device in a core network (core network, CN), which is not limited in this application.

[0122] The network equipment provides services for the cell, and the terminal device communicates with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the network equipment. The cell can belong to a macro base station (for example, macro eNB or macro gNB, etc.) or a base station corresponding to a small cell. The small cells here can include: metrocell, microcell, picocell, femtocell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0123] In an embodiment of the present application, the terminal device may also be referred to as user equipment (UE), access terminal equipment, user unit, user station, mobile station, mobile station, remote station, remote terminal equipment, mobile device, user terminal equipment, terminal equipment, wireless communication equipment, user agent or user device.

[0124] A terminal device may be a device that provides voice / data connectivity to a user, for example, a handheld device or vehicle-mounted device with wireless connection function. Currently, some examples of terminal devices may include: mobile phones, tablet computers, computers with wireless transceiver functions (such as laptop computers, PDAs, etc.), mobile internet devices (MIDs), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminal devices in industrial control, wireless terminal devices in self-driving, wireless terminal devices in remote medical, wireless terminal devices in smart grids, wireless terminal devices in transportation safety, wireless terminal devices in smart cities, wireless terminal devices in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), and so on. digital assistant, PDA), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, vehicle-mounted devices, wearable devices, terminal devices in 5G networks, or terminal devices in future evolved public land mobile networks (PLMN), etc.

[0125] Wearable devices, also known as wearable smart devices, are a general term for wearable devices that use wearable technology to intelligently design and develop wearable devices for daily wear, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include those that are fully functional, large in size, and can achieve full or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0126] Furthermore, terminal devices can also be end devices in the Internet of Things (IoT) system. IoT is a crucial component of future information technology development. Its primary technical feature is connecting objects to the Internet through communications technology, thereby enabling intelligent networks that interconnect humans and machines, and objects and things. IoT technology, for example, can achieve massive connectivity, deep coverage, and power-saving end devices through narrowband NB technology.

[0127] In addition, terminal devices can also include sensors such as smart printers, train detectors, and gas stations. Their main functions include collecting data (part of the terminal devices), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0128] To facilitate understanding of the embodiments of this application, first Figure 1 A communication system applicable to the method provided in the embodiments of the present application is described in detail. Figure 1 A schematic diagram of a communication system applicable to the method provided in an embodiment of the present application is shown. As shown in the figure, the communication system may include at least one network device; the communication system may also include at least one terminal device. The terminal device in the communication system may be mobile or fixed. The network device and the terminal device may communicate via a wireless link. Each network device may provide communication coverage for a specific geographical area and may communicate with terminal devices located within the coverage area. For example, the network device may send configuration information to the terminal device, and the terminal device may send uplink data to the network device based on the configuration information; for another example, the network device may send downlink data to the terminal device. Therefore, Figure 1 The network devices and terminal devices in the network constitute a communication system.

[0129] Optionally, the terminal devices may communicate with the network devices separately. The terminal devices may communicate directly with each other.

[0130] It should be understood that Figure 1 The exemplary embodiment shows a network device and multiple terminal devices, as well as the communication links between the communication devices. Optionally, the communication system may include multiple network devices, and each network device may include another number of terminal devices within its coverage area, such as more or fewer terminal devices. This application does not limit this.

[0131] The above-mentioned communication devices, such as Figure 1The network devices and terminal devices in the present invention may be configured with multiple antennas. These multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. In addition, each communication device also includes a transmitter chain and a receiver chain. Those skilled in the art will understand that they may include multiple components related to signal transmission and reception (such as processors, modulators, multiplexers, demodulators, demultiplexers, or antennas). Therefore, the network devices and terminal devices can communicate using MIMO technology.

[0132] Optionally, the wireless communication system may further include other network entities such as a network controller and a mobility management entity, but the embodiments of the present application are not limited thereto.

[0133] The relevant functions of the terminal equipment and network equipment in the embodiment of the present application can be Figure 2A It is implemented by the communication device 200 in FIG. Figure 2A This is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. Figure 2A As shown, the communication device 200 may include: a processor 201 , a transceiver 205 , and optionally a memory 202 .

[0134] The transceiver 205 may be referred to as a transceiver unit, a transceiver, or a transceiver circuit, etc., and is configured to implement transceiver functions. The transceiver 205 may include a receiver and a transmitter. The receiver may be referred to as a receiver or a receiving circuit, etc., and is configured to implement a receiving function; the transmitter may be referred to as a transmitter or a transmitting circuit, etc., and is configured to implement a transmitting function.

[0135] The memory 202 may store a computer program or software code or instruction 204, which may also be referred to as firmware. The processor 201 may control the MAC layer and the PHY layer by running the computer program or software code or instruction 203 therein, or by calling the computer program or software code or instruction 204 stored in the memory 202, to implement the signal transmission method provided in the following embodiments of the present application. The processor 201 may be a central processing unit (CPU), and the memory 202 may be, for example, a read-only memory (ROM) or a random access memory (RAM).

[0136] The processor 201 and transceiver 205 described in this application can be implemented on an integrated circuit (IC), an analog IC, a radio frequency integrated circuit RFIC, a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc.

[0137] The communication device 200 may further include an antenna 206. The modules included in the communication device 200 are merely examples and are not limited in this application.

[0138] As mentioned above, the communication device 200 described in the above embodiment may be a network device or a terminal device, but the scope of the communication device described in this application is not limited thereto, and the structure of the communication device may not be limited thereto. Figure 2A The communication device may be an independent device or may be part of a larger device. For example, the communication device may be implemented as follows:

[0139] (1) An independent integrated circuit IC, or chip, or chip system or subsystem; (2) A collection of one or more ICs, optionally, the IC collection may also include a storage component for storing data and instructions; (3) A module that can be embedded in other devices; (4) Receivers, smart terminals, wireless devices, handheld devices, mobile units, vehicle-mounted devices, cloud devices, artificial intelligence devices, etc.; (5) Others, etc.

[0140] For the case where the communication device is implemented as a chip or a chip system, please refer to Figure 2B Schematic diagram of the chip structure shown. Figure 2B The chip shown includes a processor and an interface. The number of processors can be one or more, and the number of interfaces can be multiple. The interfaces are used to receive and transmit signals. Optionally, the chip or chip system may include a memory. The memory is used to store the necessary program instructions and data for the chip or chip system.

[0141] The embodiments of the present application do not limit the scope of protection and applicability of the claims. Those skilled in the art may make adaptive changes to the functions and arrangements of the elements involved in this application without departing from the scope of the embodiments of the present application, or omit, replace, or add various processes or components as appropriate.

[0142] like Figure 3AThe THP precoding process block diagram shown in FIG. includes the nonlinear precoding process and the linear precoding process. Based on the scenario where the number of transmit antennas is equal to the total number of receive antennas of all terminal devices participating in MIMO transmission and equal to the total number of transmission streams L of all users, the THP precoding process is explained. Figure 3B As shown in the flowchart, in the related art, the THP precoding process includes the following steps:

[0143] 301. The network device performs interference cancellation and modulus calculation on a transmission modulation symbol vector based on a feedback matrix to obtain a transmission symbol vector.

[0144] It should be understood that the above-mentioned interference elimination and modulus calculation may also be other similar operations or equivalent operations, and step 301 may also be understood as a nonlinear precoding process.

[0145] For example, assuming that n terminal devices participate in MIMO transmission, the n terminal devices can be recorded as terminal device 1, terminal device 2, ..., terminal device n.

[0146] The terminal device participating in MIMO transmission may be a terminal device participating in pairing, or a terminal device participating in multi-user MU-MIMO transmission.

[0147] For example, terminal device k can be understood as the kth terminal device, k = 1, 2, ..., n. Each terminal device corresponds to the transmitted symbol vector Among them L k Indicates the number of transmission streams sent by terminal device k. k,l (l∈[1,L k ]) represents the symbol sent by the lth transmission stream corresponding to the terminal device k. In the nonlinear processing stage, the network device sends a symbol vector s=(s1,s2,…,s n ) T Interference cancellation is performed, and a modulo operation is performed after the interference cancellation operation to prevent the interference cancellation operation from causing the transmission power to be unlimited.

[0148] After the modular operation, the network device obtains the transmission symbol vector x=(x1,x2,…,x n ) T The total number of transmission streams corresponding to n terminal devices is Each element in the multi-user transmitted symbol vector s can be rearranged and indexed as s = (s1, s2, ..., s L ) T Similarly, each element in the transmitted symbol vector x is rearranged into indices, and is recorded as x=(x1,x2,…,x L ) T .

[0149] Specifically, the feedback matrix B can be expressed as B=GR H The dimension of the feedback matrix B is L×L.

[0150] Among them, the R matrix is ​​obtained by the complete channel matrix of all users The conjugate transpose matrix of is decomposed by QR to obtain: H =QR. Where H k Represents the channel matrix corresponding to terminal device k, with dimension N represents the number of receiving antennas of terminal device k, T Indicates the number of transmit antennas of the network device.

[0151] The G matrix is ​​a diagonal matrix of dimension L×L, whose main diagonal elements are the reciprocals of the main diagonal elements of the R matrix, that is, where r kk Denotes the element corresponding to the kth row and kth column of the matrix R. Matrix B is a lower triangular matrix with all diagonal elements set to 1. Matrix Q is a unitary matrix of dimension L×L.

[0152] For the k-th spatial layer composed of n terminal devices, the network device performs interference elimination and modulus calculation on the transmitted modulation symbol vector and outputs the transmitted symbol x k It can be expressed as:

[0153]

[0154] Among them B k,l Represents the element corresponding to the kth row and lth column of the B matrix. Mod τ {x} represents a modular operation, and the modular operation parameter is τ. Used to constrain the power of transmitted symbols after nonlinear operation. k Indicates the integral part of the k-th spatial layer obtained by the modulo operation. In this application, one spatial layer corresponds to one transport stream.

[0155] Through the above nonlinear operation, the transmitted symbol vector can be expressed as:

[0156] x=B -1 v;

[0157] Where v=(v1,v2,…,v L ) T , v k =s k +d k τ. k=1,2,…,L.

[0158] 302. The network device performs linear precoding on the transmission symbol vector x to obtain a precoded transmission symbol vector.

[0159] Specifically, the network device uses the matrix Q to linearly precode the transmission symbol vector x to obtain the precoded transmission symbol vector β is a power normalization factor. The power normalization factor in the embodiment of the present application may also be a power adjustment factor, a power control factor, or a power factor. The power factor may be 1, or a real number greater than 1 or less than 1.

[0160] The signal received by one or more terminal devices participating in MIMO transmission can be expressed as Where n is additive white Gaussian noise, and or interference.

[0161] y=(y1,y2,…,y n ) T ,y k represents the received symbol vector corresponding to terminal device k, y k,l represents the received signal corresponding to the lth receiving antenna of terminal device k. The G matrix is ​​a diagonal matrix. Therefore, through THP precoding, the multi-user multi-antenna channel can be converted into parallel sub-channels, and the received signal corresponding to the uth terminal device can be expressed as in, is the matrix G -1 The submatrix corresponding to the u-th terminal device in,

[0162] The transmission stream corresponding to the u-th spatial layer of terminal device k, and the corresponding equivalent channel coefficient are is a matrix The elements on the main diagonal in the row corresponding to the u-th spatial layer of terminal device k in .

[0163] The terminal device can use the demodulation reference signal (DMRS) sent by the network device to perform channel estimation to obtain the equivalent channel coefficient

[0164] Based on the above introduction to THP precoding, THP precoding depends on the channel matrix QR decomposition of H H =QR. Where, Q matrix is ​​N T ×N T The unitary matrix, R matrix is The dimension of the feedback matrix B used by the network device to perform serial interference cancellation during the nonlinear precoding phase should be L×L. When the total number of transmission streams of n terminal devices participating in MIMO transmission is Less than the total number of receiving antennas of multiple terminal devices When B=GR, the feedback matrix B cannot be directly passed due to matrix dimension mismatch. H A square matrix of dimension L×L is obtained. n is the number of terminal devices participating in MIMO transmission.

[0165] In the related art, the solution to the above matrix dimension mismatch problem is to select L row vectors in the R matrix to form a new matrix Accordingly, select L corresponding column vectors in the Q matrix to form a new matrix Matrix based on row / column selection and Perform THP precoding.

[0166] Such a solution, when the number of transmitting antennas is large, The value of is also large, and the QR decomposition complexity of the channel matrix H is high. In addition, the total number of transmission streams of n terminal devices is Less than the total number of receiving antennas of multiple terminal devices When , this solution will cause strong inter-user interference and inter-stream interference in the signals received by some receiving antennas, affecting the detection performance of the receiving end.

[0167] An embodiment of the present application provides a signal transmission method for MIMO transmission.

[0168] like Figure 4 As shown in the flowchart, the signal transmission method of the embodiment of the present application includes:

[0169] 401. The network device performs the following operations according to the first channel matrix: Precoding the first reference signal s1 to obtain a first transmit signal x1;

[0170] The first channel matrix It is obtained based on the second channel matrix H, the first channel matrix The number of rows and / or columns is less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in MIMO transmission, and the second channel matrix H is the channel matrix of the downlink channels of the multiple terminal devices.

[0171] In the embodiment of the present application, the terminal device participating in MIMO transmission may also be a terminal device participating in pairing, or a terminal device participating in multi-user MU-MIMO transmission.

[0172] The MIMO system includes n terminal devices, namely terminal device 1, terminal device 2, ..., terminal device n. Terminal device k can also be understood as the kth terminal device. k = 1, 2, ..., n.

[0173] The sum of the total number of transmission streams of n terminal devices is The first channel matrix The number of rows and columns are both greater than or equal to L.

[0174] Optionally, the second channel matrix H is a block matrix. The second channel matrix H includes the channel matrix of the downlink channel corresponding to each terminal device in the n terminal devices participating in the MIMO transmission. The second channel matrix The dimension of the second channel matrix H is or the second channel matrix The dimension of the second channel matrix H is

[0175] N represents the number of receiving antennas of terminal device k, T Indicates the number of transmitting antennas of the network device. k The element in the i-th row and j-th column in represents the channel coefficient between the i-th receiving antenna of the terminal device k and the j-th transmitting antenna pair of the network device.

[0176] For example, the second channel matrix The plurality of sub-matrices include a second channel matrix H1 of the downlink channel corresponding to terminal device 1, a channel matrix H2 of the downlink channel corresponding to terminal device 2, ..., a channel matrix H of the downlink channel corresponding to terminal device n n .

[0177] The first transmitted signal x1 may be a transmitted signal vector corresponding to the first reference signal symbols of n terminal devices after being precoded. Contains L k The first reference signal symbol corresponding to the port. Represents the first reference signal symbol corresponding to the lth port of the kth terminal device. Each reference signal port corresponds to a spatial layer. The first reference signals corresponding to different ports can be orthogonal signals. The first reference signal symbols corresponding to different ports can be multiplexed through one or more of time division multiplexing, frequency division multiplexing, and code division multiplexing. The network device can send first transmit signals corresponding to multiple first reference signals, or in other words, can send first transmit signals corresponding to multiple first reference signal symbols. Multiple first reference signals can occupy different time-frequency resources. It can be understood that the n terminal devices are terminal devices participating in MIMO transmission.

[0178] Specifically, the network device according to the first channel matrix The first reference signal corresponding to n terminal devices Precoding is performed to obtain the first transmission signal corresponding to n terminal devices The first reference signal corresponding to the terminal device k is

[0179] The first reference signal may be a demodulation reference signal (DMRS).

[0180] 402. The network device sends a first transmission signal x1;

[0181] The first transmission signal x1 is the transmission signal corresponding to the n terminal devices participating in the MIMO transmission; x1 satisfies

[0182] 403. Terminal device k receives a first received signal corresponding to terminal device k.

[0183] The first received signal The first transmission signal x1 may be transmitted to the terminal device k via the downlink channel corresponding to the terminal device k.

[0184] It can be understood that the first received signals received by the n terminal devices participating in the MIMO transmission can be jointly expressed as in, satisfy Among them, n k is additive noise, and or interference.

[0185] 404. Terminal device k receives the first signal Determine the equivalent channel coefficient corresponding to terminal device k.

[0186] The equivalent channel coefficient corresponding to the terminal device k can be used by the terminal device k to perform data detection on a data signal received via the downlink channel corresponding to the terminal device k.

[0187] The technical solution of this application, the network device according to the first channel matrix The first reference signal s1 is precoded, and the first channel matrix It is obtained based on the second channel matrix H, the first channel matrix The number of rows and / or columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, thereby reducing the difficulty of matrix calculation during the THP precoding process and making the THP precoding calculation simpler.

[0188] Specifically, the first channel matrix It is obtained by processing the second channel matrix H using a dimension reduction matrix. The dimension reduction matrix includes a receiving weight matrix W and a weight matrix V; or the dimension reduction matrix includes the receiving weight matrix W.

[0189] In this application, the weight matrix may be an outer weight matrix.

[0190] It should be understood that the precoding in the embodiments of the present application may be THP precoding or other precoding techniques. For example, the precoding may be, but is not limited to, symbol level precoding (SLP), vector perturbation (VP) precoding, zero-forcing precoding, and the like.

[0191] In a possible implementation, the second channel matrix The first channel matrix The number of rows is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, or the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0192] In another possible implementation, the second channel matrix The first channel matrix The number of columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, or the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0193] The following describes in detail a signal transmission scheme in a scenario where the dimensionality reduction matrix includes a receiving weight matrix W and an outer weight matrix V, and a signal transmission scheme in a scenario where the dimensionality reduction matrix includes a receiving weight matrix W.

[0194] 1. A signal transmission scheme in a scenario where the dimensionality reduction matrix includes a receiving weight matrix W and a weight matrix V.

[0195] In some possible implementations, the first channel matrix Second channel matrix The number of rows in the receiving weight matrix W is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission. The number of rows of the receiving weight matrix W and the number of columns of the weight matrix V are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, that is, the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in MIMO transmission.

[0196] In some other possible implementations, the first channel matrix Second channel matrix The number of columns of the weight matrix V is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, that is, the first channel matrix The number of columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in MIMO transmission. Or the number of rows of the receiving weight matrix W and the number of columns of the weight matrix V are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in MIMO transmission, that is, the first channel matrix The number of rows and columns of are both less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in MIMO transmission.

[0197] The weight matrix V includes the weight submatrix V corresponding to each terminal device in the multiple terminal devices k , weight matrix V=[V1… V n ], the dimension of the weight matrix V is N T ×L. Weight submatrix V of terminal device k k The dimension is N T ×L k . L k is the number of transmission streams of terminal device k, k = 1, 2, ..., n. Weight sub-matrix V k It is the channel matrix H of the network device according to the downlink channel of terminal device k k Determined. n is the number of terminal devices participating in MIMO transmission. If the weight matrix is ​​an outer weight matrix, the outer weight matrix may include an outer weight submatrix corresponding to each terminal device. In other words, the weight submatrix may be an outer weight submatrix.

[0198] For example, for the weight submatrix V corresponding to terminal device k k , the network device can use the channel matrix H of the downlink channel of the terminal device k k Perform singular value decomposition (SVD), that is Among them, U k Dimension The unitary matrix, V k is dimension N T ×N T The unitary matrix, D k is a diagonal matrix whose main diagonal elements are H k The corresponding singular values.

[0199] V k The largest L k L corresponding to the singular valuek The matrix composed of right eigenvectors is used as the weight submatrix V k Or the covariance matrix of the channel matrix of the downlink channel of the terminal device k by the network device Perform eigenvalue decomposition (EVD), that is V k is dimension N T ×N T The unitary matrix, Λ k is a diagonal matrix whose main diagonal elements are H k The corresponding eigenvalue. k The largest L k L corresponding to the eigenvalue k The matrix composed of right eigenvectors is used as the weight submatrix V k .

[0200] The receiving weight matrix W includes the receiving weight sub-matrices W1, W2, ..., W corresponding to each terminal device in the n terminal devices. n , where the receiving weight matrix W is a block diagonal matrix, k=1,2,……,n,the dimension is

[0201] The kth sub-matrix corresponding to the main diagonal of the receiving weight matrix W is the receiving weight sub-matrix W corresponding to terminal device k k The receiving weight matrix W corresponding to terminal device k k It is the weight sub-matrix V corresponding to the receiver type of the terminal device k and the terminal device k. k Determined. It can be expressed algebraically as W k =f(H k V k ). Among them, f(H k V k ) indicates that the k V k Perform corresponding processing, which may be a linear processing method or a nonlinear processing method.

[0202] W n The dimension is The receive matrix W is a block diagonal matrix, and the sub-matrices on the diagonal are the receive weight matrices corresponding to each terminal device from terminal device 1 to terminal device n. Terminal device k can be understood as any one of the n terminal devices participating in MIMO transmission.

[0203] For example, if the receiver type sent by the terminal device is an MRC receiver, W k =(H k V k ) HIf the receiver type sent by the terminal device is an MMSE receiver, W k =[(H k V k ) H (H k V k )+σ 2 I] -1 (H k V k ) H . Where I is the identity matrix. σ 2 It is an adjustment factor related to the transmitted signal power and / or noise power.

[0204] In this way, the network device calculates the receiving weight matrix only by relying on the channel matrix H corresponding to each terminal device. k and weight submatrix V k , does not rely on the channel information of other users, does not require joint detection or notification of other users' channel state information (CSI). In this way, when the terminal device at the receiving end detects the signal, it can use a simpler method to estimate the receiving weight matrix W corresponding to the terminal device. k The corresponding estimated receiving weight matrix W k , thereby reducing the processing complexity of the terminal device.

[0205] In the scenario where the dimensionality reduction matrix includes the receiving weight matrix W and the weight matrix V, in the channel estimation phase, the network device uses the first channel matrix The reference signal is linearly precoded to obtain a transmission signal, and the transmission signal is sent to the terminal device participating in the MIMO transmission. The terminal device participating in the MIMO transmission receives the reception signal transmitted via the downlink channel corresponding to the terminal device, based on the estimated reception weight matrix W' corresponding to the terminal device. k Perform channel estimation on the received signal to obtain the equivalent channel parameters corresponding to the terminal device.

[0206] In the data signal transmission stage, taking THP precoding as an example, the network device firstly generates a signal according to the first channel matrix. The obtained feedback matrix B is used to perform nonlinear precoding on the transmission data signals corresponding to one or more terminal devices to eliminate interference, obtaining a precoded transmission data signal, and then linearly precoding the transmission data symbols based on the weight matrix V to obtain a precoded transmission data signal c. The receiving end receives the precoded transmission data signal c and transmits the corresponding reception data signal through the downlink channel of the terminal device, and estimates the reception weight matrix W' corresponding to the terminal device. k and the equivalent channel parameters corresponding to the terminal device, and detect the received data signal.

[0207] Optionally, the first channel matrix The number of rows and / or columns is the sum L of the number of transmission streams of multiple terminal devices.

[0208] For example, the channel matrix The first channel matrix The number of rows is the sum of the number of transmission streams of multiple terminal devices L or the first channel matrix The number of rows and columns of are the sum of the number of transmission streams of multiple terminal devices, L. For another example, the channel matrix The first channel matrix The number of columns is the sum of the number of transmission streams of multiple terminal devices L or the first channel matrix The number of rows and columns is the sum L of the number of transmission streams of multiple terminal devices.

[0209] The first channel matrix As an example, the technical solution of the signal transmission method of the present application is described in the scenario where the dimensionality reduction matrix includes the receiving weight matrix W. Specifically, Figure 5A As shown in the flowchart, in a specific embodiment, the signal transmission method includes the following steps:

[0210] 501. A network device precodes a first reference signal s1 according to a matrix Q and a weight matrix V to obtain a first transmit signal x1.

[0211] The Q matrix is ​​the first channel matrix according to which the network device Perform QR decomposition to obtain The Q matrix is ​​a unitary matrix. The R matrix is ​​an upper triangular matrix.

[0212] The first channel matrix The number of rows and / or columns of is less than or equal to the sum of the number of receiving antennas of n terminal devices participating in MIMO transmission.

[0213] For example, the first channel matrix The number of rows and columns of can be the sum of the number of transmission streams of multiple terminal devices, L, the dimension of Q is L×L, and the dimension of R is L×L. It is a square matrix, which avoids the matrix dimension mismatch problem caused by the number of transmission streams L being less than the total number of receiving antennas, and can flexibly adapt to various antenna configurations and transmission scenarios.

[0214] In one possible implementation, α is a power control factor. The network device precodes the first reference signal s1 corresponding to the n terminal devices participating in the MIMO transmission according to the matrix Q and the weight matrix V to obtain a first transmission signal x1.

[0215] The first reference signal symbol corresponding to the lth transmitting antenna. The first reference signal corresponding to the terminal device k Contains L k The first reference signal symbol corresponding to the port, Represents the first reference signal symbol corresponding to the lth port of the kth terminal device. Each reference signal port corresponds to a spatial layer. The first reference signals corresponding to different ports can be orthogonal signals. The first reference signal symbols corresponding to different ports can be multiplexed using one or more of time division multiplexing, frequency division multiplexing, and code division multiplexing.

[0216] The network device may send multiple first reference signals, or may send multiple first reference signal symbols. Multiple first reference signals may occupy different time-frequency resources. Terminal device k is any one of the n terminal devices participating in MIMO transmission. If the first reference signal corresponding to each terminal device is an orthogonal signal, the first reference signal corresponding to terminal device k is an orthogonal signal. It can be expressed as: Among them, P k In the matrix VQ The corresponding column vectors form a matrix with dimension N T ×L k .

[0217] In another possible implementation, Among them, the matrix B can be expressed as B = GR H , G matrix diagonal matrix. For example, the first channel matrix The number of rows and columns of can be the sum of the number of transmission streams of multiple terminal devices L, and the G matrix is ​​a diagonal matrix of dimension L×L, and its main diagonal elements are the reciprocals of the main diagonal elements of the R matrix, that is, The dimension of matrix B is L × L. α is the power control factor.

[0218] The network device precodes the first reference signal s1 corresponding to the n terminal devices participating in the MIMO transmission according to the matrix Q, the matrix B and the weight matrix V to obtain a first transmission signal x1.

[0219] The first reference signal symbol corresponding to the lth transmitting antenna. The first reference signal corresponding to the terminal device k Contains L k The first reference signal symbol corresponding to the port, Indicates the first reference signal symbol corresponding to the lth port of the kth terminal device.

[0220] If the first reference signal corresponding to each terminal device is an orthogonal signal, the first transmitted signal corresponding to terminal device k It can be expressed as: Among them, P k Representation matrix VQB -1 middle The corresponding column vectors form a matrix with dimension N T ×L k .

[0221] 502. The network device sends a first transmission signal x1.

[0222] 503. Terminal device k receives a first received signal corresponding to terminal device k.

[0223] The first received signal y1 corresponds to the first transmitted signal x1. In the implementation mode of , the first received signal received by the n terminal devices participating in MIMO transmission can be expressed as Where n is additive white Gaussian noise and / or interference, where is the first received signal corresponding to terminal device k, where k = 1, 2, ..., n.

[0224] Second channel matrix The first received signal corresponding to n terminal devices participating in MIMO transmission:

[0225]

[0226] For the convenience of expression, the definition Then the first received signal corresponding to the kth terminal device is Among them, n k is the additive white Gaussian noise and / or interference corresponding to terminal device k,

[0227] In the above In the implementation mode of , the first received signal received by the n terminal devices participating in MIMO transmission can be expressed as

[0228] Where n is additive white Gaussian noise, where is the first received signal corresponding to terminal device k, where k = 1, 2, ..., n.

[0229] Second channel matrix The first received signal corresponding to n terminal devices participating in MIMO transmission:

[0230]

[0231] For the convenience of expression, the definition Then the first received signal corresponding to the kth terminal device is n k is additive white Gaussian noise and / or interference.

[0232] 504. The terminal device k determines the receiving weight matrix W corresponding to the terminal device k. k The corresponding estimated receiving weight matrix W' k ;

[0233] For example, the terminal device k can determine the receiving weight matrix W according to the second receiving signal corresponding to the second sending signal sent by the network device. k Alternatively, the terminal device k may determine the receiving weight matrix W in accordance with the method agreed with the network device. k The corresponding estimated receiving weight matrix W' k . Estimate the receiving weight matrix W' k It can be understood as the receiving weight matrix W k The estimation matrix of .

[0234] It can be understood that step 504 can be performed after step 503 or before step 503.

[0235] 505. The terminal device k receives the weight matrix W' according to the estimated k The first received signal corresponding to terminal device k Get the equivalent channel coefficient corresponding to terminal device k.

[0236] Specifically, the terminal device k can use the estimated receiving weight matrix W′ k Left multiply the first received signal Obtain a third received signal corresponding to the first received signal

[0237] The terminal device k receives the third signal The first reference signal corresponding to terminal device k Get the equivalent channel coefficient corresponding to terminal device k.

[0238] For example, based on the above The implementation method of the third receiving signal corresponding to the terminal device k The corresponding third received signals of the corresponding terminal devices 1 to n are:

[0239]

[0240] Among them, n kand n′ are additive white Gaussian noise.

[0241] Estimated receiver weight matrix The estimated receiving weight matrix W′ can be understood as the estimated matrix of the receiving weight matrix W. The estimated receiving weight matrix W′ can be equivalent to the receiving weight matrix W superimposed on the channel estimation error matrix, that is, W′=W+Δ W The estimated receiving weight matrix W′ is a block diagonal matrix, which includes W1, W2, ..., W contained in the receiving weight matrix W. n The corresponding estimated receiving weight matrices W′1, W′2, ..., W′ n In an ideal situation, assuming W′=W, the above formula can be expressed as When there is a channel estimation error,

[0242] Among them, the R matrix is ​​the first channel matrix Perform QR decomposition to obtain In this way, the first channel matrix used by the network device for precoding is It is based on the receiving weight matrix W k The terminal device estimates the receiving weight matrix W′ according to the obtained k Left multiply the first received signal The data received signal Determine the equivalent channel coefficients. Network devices and terminal devices use the same receiver assumptions for calculation and processing, ensuring matching between transmitter and receiver calculations. This avoids the need for uplink or downlink notification of detection weight matrices.

[0243] The estimated receiving weight matrix W′ has the same dimension as the receiving weight matrix W. The elements in the estimated receiving weight matrix W′ and the elements at the same position in the receiving weight matrix W may be the same or close in value.

[0244] R H is a lower triangular matrix, and the R matrix is ​​the first channel matrix After QR decomposition, we can get R H The elements on the main diagonal of each row correspond to the equivalent channel coefficients of a transport stream, which can be used to detect the data transmitted by the transport stream.

[0245] Terminal device k receives the signal through the third terminal device k Perform channel estimation to obtain equivalent channel coefficients corresponding to one or more transmission streams corresponding to terminal device k.

[0246] For example, if the number of transmission streams corresponding to terminal device k is m, then terminal device k can receive the third signal corresponding to terminal device k by Perform channel estimation. The first reference signal corresponding to terminal device k The terminal device k and the network device at both ends of the transmission and reception are known, and the terminal device k can receive the signal according to the third Get R H In the example, the main diagonal elements on the m rows corresponding to the terminal device k are the equivalent channel coefficients corresponding to the m transmission streams. In one implementation, if the first reference signal corresponding to each terminal device is an orthogonal signal, the third received signal corresponding to the terminal device k is It can be expressed as in express The submatrix composed of the elements corresponding to the rows and columns corresponding to the terminal device k.

[0247] The terminal device k can receive the third signal corresponding to the terminal device k by Based on the first reference signal Perform channel estimation and obtain the estimation result The lth main diagonal element in is the equivalent channel coefficient corresponding to the lth data stream corresponding to terminal device k.

[0248] The terminal device k can detect the data signal transmitted by each transmission stream according to the equivalent channel coefficient corresponding to the transmission stream.

[0249] For example, based on the above The implementation method of the third receiving signal corresponding to the terminal device k The corresponding third received signals of the corresponding terminal devices 1 to n are:

[0250]

[0251] Where n and n′ are additive white Gaussian noise.

[0252] Estimated receiver weight matrix The estimated receiving weight matrix W′ can be understood as the estimated matrix of the receiving weight matrix W. The estimated receiving weight matrix W′ can be equivalent to the receiving weight matrix W superimposed on the channel estimation error matrix, that is, W′=W+Δ W .

[0253] The estimated receiving weight matrix W′ is a block diagonal matrix, which includes W1, W2, ..., W contained in the receiving weight matrix W. n The corresponding estimated receiving weight matrices W′1, W′2, ..., W′ n In an ideal situation, assuming W′=W, the above formula can be expressed as When there is a channel estimation error,

[0254] The G matrix is ​​related to the R matrix, and the R matrix is ​​the matrix of the first channel according to the network device. Perform QR decomposition to obtain The G matrix is ​​a diagonal matrix whose main diagonal elements are the reciprocals of the main diagonal elements of the R matrix, that is,

[0255] The third received signal corresponding to terminal device k or Where n and n′ are additive white Gaussian noise.

[0256] in, is the matrix G -1 The submatrix corresponding to the k-th terminal device in,

[0257] The estimated receiving weight matrix W′ has the same dimension as the receiving weight matrix W. The elements in the estimated receiving weight matrix W′ and the elements at the same position in the receiving weight matrix W may be the same or close in value.

[0258] G -1 is a diagonal matrix, G -1 Each element on the main diagonal corresponds to an equivalent channel coefficient of a transport stream, which can be used to detect the data transmitted by the transport stream.

[0259] Terminal device k receives the signal through the third terminal device k Perform channel estimation to obtain equivalent channel coefficients corresponding to one or more transmission streams corresponding to terminal device k.

[0260] For example, if the number of transmission streams corresponding to terminal device k is m, then terminal device k can receive the third signal corresponding to terminal device k by Perform channel estimation. First reference signal The terminal device k and the network device at both ends of the transmission and reception are known, and the terminal device k can receive the signal according to the third get There are m main diagonal elements in , and the m diagonal elements are the equivalent channel coefficients corresponding to the m transmission streams. The transmission stream corresponding to the u-th spatial layer of terminal device k, the corresponding equivalent channel coefficient is is a matrix The elements on the main diagonal in the row corresponding to the u-th spatial layer of terminal device k in .

[0261] The terminal device k can detect the data signal transmitted by each transmission stream according to the equivalent channel coefficient corresponding to the transmission stream.

[0262] In this way, each of the n terminal devices participating in the MIMO transmission can obtain its own corresponding equivalent channel coefficient, which is used by each device to subsequently detect the received data signal.

[0263] It can be seen that in the technical solution of the present application, the dimension of the channel matrix can be reduced so that the first channel matrix The number of rows and / or columns of is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission. By properly designing the weight matrix V and the receiving weight matrix W, the first channel matrix can be made The number of rows and columns of are both the sum L of the total number of transmission streams of the n terminal devices participating in MIMO transmission, which solves the problem of matrix dimension mismatch caused by the sum L of the total number of transmission streams of the n terminal devices participating in MIMO transmission being less than the sum of the total number of receiving antennas of multiple terminal devices.

[0264] Furthermore, the network device uses a first channel matrix for precoding It is based on the receiving weight matrix W k The terminal device estimates the receiving weight matrix W′ according to the obtained k Left multiply the first received signal The data received signal Determine the equivalent channel coefficients. Network devices and terminal devices use the same receiver assumptions for calculation and processing, ensuring matching between transmitter and receiver calculations. This avoids the need for uplink or downlink notification of detection weight matrices.

[0265] Furthermore, the total number of transmission streams of n terminal devices participating in MIMO transmission is Less than the total number of receiving antennas of multiple terminal devices When L row vectors are selected in the R matrix to form a new matrix Select L corresponding column vectors in the Q matrix to form a new matrix Matrix based on row / column selection and When performing THP precoding, since the number of rows of the B matrix is ​​less than the number of receiving antennas, when using the B matrix for interference cancellation, it will be impossible to completely eliminate the inter-user interference and inter-stream interference of the received signals of all antennas.

[0266] If signal detection is performed only on receive antennas without inter-user interference and inter-stream interference, while signals from receive antennas with inter-user interference and inter-stream interference are not detected, these antennas are not utilized, resulting in power loss. If signal detection is performed based on all receive antennas, the presence of inter-user interference and inter-stream interference on some receive antennas will cause severe interference in the received signals of these antennas, resulting in severe performance flatness.

[0267] By adopting the technical solution of this application, the total number of transmission streams of n terminal devices participating in MIMO transmission is Less than the total number of receiving antennas of multiple terminal devices By properly designing the weight matrix V and the receiving weight matrix W, the first channel matrix can be The number of rows of R is reduced to the same as the total number of transmission streams L of the n terminal devices participating in MIMO transmission, so that the matrix R H The number of columns is L.

[0268] Thus, the feedback matrix B = GR H , the dimension of the feedback matrix B is also L×L. This can reduce the dimension of the channel matrix of QR decomposition and reduce the computational complexity of QR decomposition.

[0269] Furthermore, the channel matrix H of the downlink channels of the n terminal devices participating in the MIMO transmission is processed into a first channel matrix of dimension L×L Then, according to the first channel matrix with dimension L×L Perform interference cancellation, the first channel matrix It is equivalent to a channel matrix of a virtual downlink channel with L receiving antennas. The number of receiving antennas of the channel matrix of the virtual downlink channel is The number of rows L.

[0270] In this way, the number of transmission streams L of the n terminal devices can be the same as the number of rows of the channel matrix of the virtual downlink channel, and the interference corresponding to each receiving antenna can be better eliminated during the interference elimination process, thereby avoiding the power loss or residual interference of the receiving antenna at the receiving end caused by the mismatch between the number of transmission streams and the number of antennas.

[0271] The following provides the terminal device to determine the estimated receiving weight matrix W' k plan.

[0272] In step 504, the terminal device k may determine the receiving weight matrix W corresponding to the terminal device according to the received second receiving signal. k The corresponding estimated receiving weight matrix W' k ;like Figure 5B In the flowchart shown in FIG. 5 , before step 504, the signal transmission method further includes the following steps:

[0273] 506. The network device sends a second transmission signal x2;

[0274] Optionally, the second transmission signal x2 is obtained by precoding the second reference signals s2 corresponding to the n terminal devices participating in the MIMO transmission by the network device according to the weight matrix V. γ is the power factor.

[0275] s2 includes second reference signals corresponding to n terminal devices. is the second reference signal corresponding to terminal device k. Represents the second reference signal symbol corresponding to the lth port of the kth terminal device. Each second reference signal port corresponds to a spatial layer. The second reference signals corresponding to different ports can be orthogonal signals. The second reference signal symbols corresponding to different ports can be multiplexed using one or more of time division multiplexing, frequency division multiplexing, and code division multiplexing.

[0276] The network device may send multiple second transmission signals, or may send multiple second transmission signal symbols. Multiple second transmission signals may occupy different time-frequency resources. The second transmission signal x2 corresponding to n terminal devices is a signal containing L k The second reference signal symbol corresponding to the port, = represents the second reference signal symbol corresponding to the lth port of terminal device k. The second reference signals of different ports can be orthogonal signals. If the second reference signal s2 of different ports is orthogonal, the second transmission signal corresponding to terminal device k

[0277] 507. Terminal device k receives the second received signal corresponding to terminal device k. The second received signal is the received signal received by the receiving end after the second transmitted signal x2 passes through the downlink channel corresponding to the terminal device k. y2=Hx2+n.

[0278] Optionally, different ports of the second reference signal s2 are orthogonal, and the second received signal corresponding to the terminal device k can be expressed as in, is additive white Gaussian noise, and or interference.

[0279] In this way, the terminal device k can receive the second received signal Determine the receiving weight matrix W corresponding to terminal device k k The corresponding estimated receiving weight matrix W' k .

[0280] Step 504 may include:

[0281] 5041. Terminal device k receives the second signal Perform channel estimation to obtain the second channel estimation matrix corresponding to terminal device k

[0282] Specifically, Reference signal The receiving end can know that the terminal device k at the receiving end can get an estimate of the equivalent channel. The dimension is N R ×L k , According to the second received signal and the second reference signal For H k V k Δ1 is the estimation error matrix corresponding to the channel estimation.

[0283] For example, the terminal device k may perform channel estimation using a least square (LS) channel estimation algorithm or a minimum mean square error (MMSE) channel estimation algorithm.

[0284] 5042. The terminal device k estimates the second channel matrix and receiver type, determine the receiving weight matrix W k The corresponding estimated receiving weight matrix W' k .

[0285] It can be understood that the estimated receiving weight matrix W' obtained by the terminal device k k is the receiving weight matrix W corresponding to the terminal device k k estimated value.

[0286] The receiving weight matrix W corresponding to terminal device k k The channel matrix H corresponding to terminal device k k And the corresponding weight matrix V k The receiver type is the receiver type sent by the terminal device k to the network device. The network device receives the receiver type sent by the terminal device k and the downlink channel H corresponding to the terminal device k. k Determine the receiving weight matrix W corresponding to terminal device k k In this way, the terminal device k can more accurately determine the receiving weight matrix W according to the receiver type sent to the network device. k The corresponding estimated receiving weight matrix W' k .

[0287] Specifically, the terminal device k calculates the estimated receiving weight matrix corresponding to the terminal device k according to the receiver type sent to the network device. in, Indicates based on Perform corresponding processing, which may be a linear processing method or a nonlinear processing method.

[0288] For example, if the receiver type of the terminal device k sending to the network device is an MRC receiver, If the receiver type sent by the terminal device is an MMSE receiver, W k =[(H k V k ) H (H k V k )+σ 2 I] -1 (H k V k ) H . Where I is the identity matrix. σ 2 It is an adjustment factor related to the transmitted signal power and / or noise power.

[0289] In this way, the terminal device k receives the second received signal corresponding to the second reference signal according to the receiver type. Determine the estimated receiving weight matrix W' corresponding to terminal device k k In the present application, in addition to the reference signal used for direct channel estimation, another reference signal (second reference signal) is also sent when performing channel estimation. Compared with the solution of direct indication through signaling, this solution of implicitly indicating the receiving weight matrix through the second reference signal can avoid the signaling notification of the receiving weight matrix, reduce the downlink signaling overhead, and avoid the performance loss caused by quantization during notification.

[0290] In the embodiment of the present application, the first reference signal and the second reference signal may be demodulation reference signals (DMRSs). DMRS resource 1 corresponding to the first reference signal and DMRS resource 2 corresponding to the second reference signal may occupy different time and frequency resources.

[0291] like Figure 5C In the scenario diagram shown, the horizontal axis represents OFDM symbols and the vertical axis represents frequency domain subcarriers. Each small grid represents a resource element. For example, DMRS resource 1 and DMRS resource 2 can be arranged in a time-division manner. DMRS resource 1 occupies the 12 subcarriers of the third OFDM symbol in a resource block (RB), and DMRS resource 2 occupies the 12 subcarriers of the ninth OFDM symbol in an RB.

[0292] Of course, in other embodiments, DMRS resource 1 and DMRS resource 2 are not limited to the following. Figure 5C The example arrangement is not limited to the time division arrangement. DMRS resource 1 and DMRS resource 2 may have different time-frequency resource mapping methods.

[0293] In other embodiments, the first reference signal and the second reference signal may also be other types of reference signals, such as a channel state information reference signal (CSI-RS), a cell information reference signal (CRS), a phase tracking reference signal (PTRS), etc.

[0294] The first reference signal and the second reference signal may be reference signals of different types. For example, the first reference signal may be a DMRS, and the second reference signal may be a CSI-RS.

[0295] It should be understood that the terminal device determines the estimated receiving weight matrix W' according to the second transmitted signal. k The scheme is used for illustration only. The present application does not limit the terminal device to only adopting the scheme of steps 505, 506 and 504 to determine the estimated receiving weight matrix W' k In other embodiments, the terminal device k may also determine the receiving weight matrix W corresponding to the terminal device according to the method agreed with the network device. k The corresponding estimated receiving weight matrix W' k .

[0296] The following describes the data signal transmission scheme in the scenario where the dimensionality reduction matrix includes the receiving weight matrix W and the weight matrix V. Specifically, Figure 6 As shown in the flowchart, the data signal transmission method includes:

[0297] 601. The network device performs the following operations according to the first channel matrix: Precoding the transmitted data signal s to obtain a precoded transmitted data signal c;

[0298] The transmission data signal s=(s1, s2, ..., s n ) T The transmitted data signal s can also be understood as the transmitted symbol vector corresponding to the n terminal devices participating in the MIMO transmission, or the multi-user transmitted symbol vector.

[0299] s k It can be expressed as s k is the sending symbol vector corresponding to terminal device k, or s k is the data signal sent by terminal device k. k,l (l∈[1,L k ]) represents the data symbol sent by the lth transmission stream corresponding to terminal device k.

[0300] Specifically, the network device is based on the first channel matrix Perform THP precoding on the transmission data signal to obtain a precoded transmission data signal C. The THP precoding includes a nonlinear precoding process and a linear precoding process.

[0301] During the nonlinear precoding process, the network device performs stream-by-stream serial interference cancellation based on the feedback matrix B. B = GR H The R matrix is ​​obtained by the first channel matrix The conjugate transposed matrix of is subjected to QR decomposition to obtain:

[0302] For example, the first channel matrix The dimension is L×L; The G matrix is ​​a diagonal matrix of dimension L×L, whose main diagonal elements are the reciprocals of the main diagonal elements of the R matrix, that is,

[0303] where r kk , represents the element corresponding to the kth row and kth column of the R matrix. Therefore, the matrix B is a lower triangular matrix with all diagonal elements set to 1. The matrix Q is a unitary matrix of dimension L×L.

[0304] n terminal devices participate in MIMO transmission, and each terminal device sends a corresponding symbol vector Among them L k Indicates the number of transport streams sent by terminal device k. k,l (l∈[1,L k ]) represents the symbol sent by the lth transmission stream of terminal device k.

[0305] During the nonlinear precoding process, the network device sends a symbol vector s=(s1,s2,…,s n ) T Interference cancellation is performed, and in order to avoid the interference cancellation operation causing the transmission power to be unlimited, a modulo operation is performed after the interference cancellation operation. After the modulo operation, the network device obtains the transmission symbol vector x=(x1,x2,…,x n ) T The total number of transmission streams sent by n terminal devices is Rearrange the index of each element in the multi-user transmission symbol vector s, and record it as s=(s1,s2,…,s L ) T Similarly, each element in the transmitted symbol vector x is rearranged into indices, and is recorded as x= (x1,x2,…,x L ) T .

[0306] For the transmission stream i corresponding to spatial layer i, the transmission symbol output by the nonlinear precoding step is B i,l Represents the element corresponding to the i-th row and l-th column of the B matrix. Mod τ {x} represents the modular operation. For a given modular operation parameter τ, d k The network device obtains the transmission symbol vector x=B by the above nonlinear operation. -1 v.

[0307] Where v=(v1,v2,…,v L ) T , which represents the transmitted data symbol vector obtained by n users after signal perturbation (modulo operation) after THP nonlinear operation, can be recorded as in Represents the transmitted data symbol vector corresponding to terminal device k after signal disturbance.

[0308] During the linear precoding process, the network device precodes the transmitted symbol vector x according to the matrix Q and the weight matrix V to obtain the transmitted data signal c corresponding to the n terminal devices participating in the MIMO transmission. Specifically, the transmitted data signal Where β is the power normalization factor.

[0309] The process of the network device performing precoding according to the matrix Q and the weight matrix V can be understood as a linear processing process.

[0310] 602. The network device sends a precoded transmit data signal c.

[0311] 603. Terminal device k receives a first received data signal

[0312] It can be understood that the received data signals of n terminal devices participating in MIMO transmission

[0313] Among them, the first received data signal The received data signal corresponding to the terminal device k among the n terminal devices.

[0314] 604. The terminal device k receives the equivalent channel coefficient and the receiving weight matrix W' corresponding to the terminal device k. k Detecting a first received data signal

[0315] Specifically, the terminal device k uses the receiving weight matrix W' corresponding to the terminal device k k, the left multiplication of the received data signal is Get the second received data signal

[0316] It can be understood that the second received data signals of the n terminal devices participating in the MIMO transmission where n represents the corresponding additive noise or interference.

[0317] Matrix G -1 It is a diagonal matrix. The main diagonal element corresponding to the i-th row and i-th column of the matrix G is R H Matrix or R matrix row i i The reciprocal of the main diagonal element corresponding to the column. where r kk Represents R H The element corresponding to the kth row and kth column of the matrix can be obtained The second received data signal corresponding to terminal device k can be expressed as Represents the symbol vector sent after the modular operation corresponding to the terminal device k.

[0318] I understand. In the matrix, the m main diagonal elements corresponding to terminal device k are the equivalent channel coefficients corresponding to the m transmission streams of terminal device k. The terminal device can use the equivalent channel coefficients obtained in step 505 to detect the received data signal and obtain an estimate of the transmitted data signal. For example, the terminal device can use the equivalent channel coefficients obtained in step 505 to equalize the received data signal and then perform a modulo operation to obtain an estimate of the transmitted data signal.

[0319] 2. The dimensionality reduction matrix includes the receiving weight matrix W.

[0320] In some possible implementations, the first channel matrix Second channel matrix The number of rows in the receiving weight matrix W is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, that is, the first channel matrix The number of rows is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0321] In some other possible implementations, the first channel matrix Second channel matrix The number of columns of the receiving weight matrix W is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission, that is, a channel matrix The number of columns is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission.

[0322] The receiving weight matrix W includes the receiving weight sub-matrices W1, W2, ..., W corresponding to each terminal device in the n terminal devices. n , where the receiving weight matrix W is a block diagonal matrix, k=1,2,……,n,the dimension is The kth sub-matrix corresponding to the main diagonal of the receiving weight matrix W is the receiving weight sub-matrix W corresponding to terminal device k k The receiving weight matrix W corresponding to terminal device k k It is determined by the network device according to the receiver type of the terminal device k.

[0323] The first channel matrix As an example, the technical solution of the signal transmission method of the present application is described in the scenario where the dimensionality reduction matrix includes the receiving weight matrix W. Specifically, Figure 7 As shown in the flowchart, the signal transmission method includes the following steps:

[0324] 701. A network device precodes a first reference signal s1 according to a matrix Q to obtain a first transmit signal x1.

[0325] The Q matrix is ​​the first channel matrix according to which the network device Perform QR decomposition to obtain The Q matrix is ​​a unitary matrix. The R matrix is ​​an upper triangular matrix.

[0326] The first channel matrix The number of rows and / or columns of is less than or equal to the sum of the number of receiving antennas of n terminal devices participating in MIMO transmission.

[0327] For example, the first channel matrix The number of rows can be the sum of the number of transmission streams of multiple terminal devices, L, the dimension of R is L×L, and the dimension of Q is N T × L. The reduced matrix R is a square matrix, which avoids the matrix dimension mismatch problem caused by the number of transmission streams L being less than the total number of receiving antennas. It can flexibly adapt to various antenna configurations and transmission scenarios.

[0328] In one possible implementation, α is a power control factor. The network device precodes the first reference signal s1 corresponding to the n terminal devices participating in the MIMO transmission according to the matrix Q to obtain the first transmission signal x1 corresponding to the n terminal devices.

[0329] The first reference signal symbol corresponding to the lth transmitting antenna. The first reference signal corresponding to the terminal device k Contains L k The first reference signal symbol corresponding to the port, The first reference signal symbol corresponding to the lth port of the kth terminal device. The first reference signals of different ports can be orthogonal signals. Terminal device k is any terminal device among the n terminal devices participating in MIMO transmission.

[0330] In another possible implementation, Among them, the matrix B can be expressed as B = GR H , the G matrix is ​​a diagonal matrix of dimension L×L, whose main diagonal elements are the reciprocals of the main diagonal elements of the R matrix, that is, The dimension of matrix B is L×L. α is a power control factor. The network device precodes the first reference signal s1 corresponding to n terminal devices participating in MIMO transmission based on matrix Q and matrix B to obtain the first transmission signal x1 corresponding to the n terminal devices.

[0331] The first reference signal symbol corresponding to the lth transmitting antenna. The first reference signal corresponding to the terminal device k Contains L k The first reference signal symbol corresponding to the port, The first reference signal symbol corresponding to the lth port of the kth terminal device. The first reference signals of different ports can be orthogonal signals. Terminal device k is any terminal device among the n terminal devices participating in MIMO transmission.

[0332] 702. The network device sends a first transmission signal x1.

[0333] 703. Terminal device k receives a first received signal

[0334] The first received signal y1 corresponds to the first transmitted signal x1. Under the implementation mode of , the vector received by n terminal devices participating in MIMO transmission can be expressed as Where n is additive white Gaussian noise and / or interference. is the first received signal corresponding to terminal device k, where k = 1, 2, ..., n.

[0335] Second channel matrix The first received signal corresponding to n terminal devices participating in MIMO transmission:

[0336]

[0337] The R matrix and Q matrix are the first channel matrices of the network equipment Perform QR decomposition to obtain For the convenience of expression, the definition Then the first received signal corresponding to the kth terminal device is n k is additive white Gaussian noise, and or interference.

[0338] In the above Under the implementation mode of , the vector received by n terminal devices participating in MIMO transmission can be expressed as Where n is additive white Gaussian noise. is the first received signal corresponding to terminal device k, where k = 1, 2, ..., n.

[0339] Second channel matrix The first received signal corresponding to n terminal devices participating in MIMO transmission:

[0340]

[0341] The R matrix and Q matrix are the first channel matrices of the network equipment Perform QR decomposition to obtain For the convenience of expression, the definition Then the first received signal corresponding to the kth terminal device is n k is additive white Gaussian noise and / or interference.

[0342] 704. Terminal device k determines the receiving weight matrix W corresponding to terminal device k. k The corresponding estimated receiving weight matrix W' k ;

[0343] For example, the terminal device k may also determine the receiving weight matrix W according to the second receiving signal corresponding to the second sending signal sent by the network device. k Alternatively, the terminal device k can determine the receiving weight matrix W in accordance with the method agreed with the network device. k The corresponding estimated receiving weight matrix W' k . Estimate the receiving weight matrix W' k It can be understood as the receiving weight matrix W k The estimation matrix of .

[0344] It can be understood that step 704 can be performed after step 703 or before step 703.

[0345] 705. The terminal device k receives the weight matrix W' according to the estimatedk The first received signal corresponding to terminal device k Get the equivalent channel coefficient corresponding to terminal device k.

[0346] Specifically, the terminal device k can use the estimated receiving weight matrix W′ k Left multiply the first received signal Obtain a third received signal corresponding to the first received signal

[0347] The terminal device k receives the third signal The first reference signal corresponding to terminal device k Get the equivalent channel coefficient corresponding to terminal device k.

[0348] For example, based on the above The implementation method of the third receiving signal corresponding to the terminal device k The corresponding third received signals of terminal devices 1 to n:

[0349]

[0350] Based on the above description of the relationship between the receiving weight matrix W and the estimated receiving weight matrix W′ in the scenario where the dimensionality reduction matrix includes the receiving weight matrix W, in an ideal case, assuming W′=W, the above formula can be expressed as When there is a channel estimation error,

[0351] First reference signal Since k is known for the network devices and terminal devices on both the transmitting and receiving sides, the equivalent channel matrix can be obtained In one implementation, if the first reference signal corresponding to each terminal device is an orthogonal signal, the third received signal corresponding to terminal device k is It can be expressed as

[0352] in express The terminal device k can receive the signal from the third terminal device k by Based on the first reference signal Perform channel estimation and obtain the estimation result The lth main diagonal element in is the equivalent channel coefficient corresponding to the lth data stream corresponding to terminal device k.

[0353] In this way, the first channel matrix used by the network device for precoding is It is based on the receiving weight matrix W kThe terminal device obtains the first received signal by multiplying the estimated receiving weight matrix W′ by the left The data received signal Determine the equivalent channel coefficients. Network devices and terminal devices use the same receiver assumptions for calculation and processing, ensuring matching between transmitter and receiver calculations. This avoids the need for uplink or downlink notification of detection weight matrices.

[0354] The estimated receiving weight matrix W′ has the same dimension as the receiving weight matrix W. The elements in the estimated receiving weight matrix W′ and the elements at the same position in the receiving weight matrix W may be the same or close in value.

[0355] R H or is a lower triangular matrix, and the R matrix is ​​the first channel matrix Obtained through QR decomposition. The elements on the main diagonal of each row correspond to the equivalent channel coefficients of a transport stream, which can be used to detect the data transmitted by the transport stream.

[0356] For example, based on the above The implementation method of the third receiving signal corresponding to the terminal device k The corresponding third received signals of terminal devices 1 to n:

[0357]

[0358] Estimated receiver weight matrix The estimated receiving weight matrix W′ can be understood as the estimated matrix of the receiving weight matrix W. The estimated receiving weight matrix W′ can be equivalent to the receiving weight matrix W superimposed on the channel estimation error matrix, that is, W′=W+Δ W The estimated receiving weight matrix W′ is a block diagonal matrix, which includes W1, W2, ..., W contained in the receiving weight matrix W. n The corresponding estimated receiving weight matrices W′1, W′2, ..., W′ n .

[0359] In an ideal situation, assuming W′=W, the above formula can be expressed as When there is a channel estimation error,

[0360] The G matrix is ​​related to the R matrix, and the R matrix is ​​the matrix of the first channel according to the network device. Perform QR decomposition to obtain The G matrix is ​​a diagonal matrix whose main diagonal elements are the reciprocals of the main diagonal elements of the R matrix, that is, The data receiving signal corresponding to terminal device k or in, is the matrix G -1 The submatrix corresponding to the k-th terminal device in,

[0361] in, is a matrix The submatrix corresponding to the k-th terminal device in, Since the first reference signal Since the network equipment and terminal equipment on both the transmitting and receiving sides are known, the equivalent channel matrix can be obtained Estimates. The elements on the main diagonal of each row correspond to the equivalent channel coefficients of a transport stream, which can be used to detect the data transmitted by the transport stream.

[0362] In this way, the first channel matrix used by the network device for precoding is It is based on the receiving weight matrix W k The terminal device estimates the receiving weight matrix W′ according to the obtained k Left multiply the first received signal The data received signal Determine the equivalent channel coefficients. Network devices and terminal devices use the same receiver assumptions for calculation and processing, ensuring matching between transmitter and receiver calculations. This avoids the need for uplink or downlink notification of detection weight matrices.

[0363] The estimated receiving weight matrix W′ has the same dimension as the receiving weight matrix W. The elements in the estimated receiving weight matrix W′ and the elements at the same position in the receiving weight matrix W may be the same or close in value.

[0364] G -1 is a diagonal matrix, G -1 Each element on the main diagonal corresponds to an equivalent channel coefficient of a transport stream, which can be used to detect the data transmitted by the transport stream.

[0365] It can be seen that in the technical solution of the present application, the dimension of the channel matrix can be reduced so that the first channel matrix The number of rows and / or columns of is less than or equal to the sum of the number of receiving antennas of the n terminal devices participating in the MIMO transmission. By properly designing the receiving weight matrix W, the first channel matrix can be made The number of rows is the sum L of the total number of transmission streams of the n terminal devices participating in the MIMO transmission, which solves the problem of matrix dimension mismatch caused by the sum L of the total number of transmission streams of the n terminal devices participating in the MIMO transmission being less than the sum of the total number of receiving antennas of multiple terminal devices.

[0366] The following provides the terminal device to determine the estimated receiving weight matrix W' k plan.

[0367] In step 704, the terminal device k may determine the receiving weight matrix W corresponding to the terminal device according to the received second receiving signal. k The corresponding estimated receiving weight matrix W' k Before step 704, the signal transmission method further includes the steps of:

[0368] 706. The network device sends a second transmission signal x2.

[0369] Optionally, the second transmitted signal may be understood as a second reference signal corresponding to n terminal devices. γ is the power factor, and the value of γ can be 1.

[0370] in, s2 includes second reference signals corresponding to n terminal devices. is the second reference signal corresponding to terminal device k. The second transmission signal corresponding to terminal device k For the explanation of x2, please refer to the relevant description in the signal transmission scheme in the scenario where the dimensionality reduction matrix includes the receiving weight matrix W and the weight matrix V, and will not be repeated here.

[0371] 707. Terminal device k receives the second received signal corresponding to terminal device k. The second received signal is the received signal received by the receiving end after the second transmitted signal x2 passes through the downlink channel corresponding to the terminal device k. y2 = Hx2 + n. If the second reference signal s2 at different ports is orthogonal, the second received signal corresponding to the terminal device k can be expressed as in, is additive white Gaussian noise, and or interference.

[0372] In this way, the terminal device k can receive the second received signal Determine the receiving weight matrix W corresponding to terminal device k k The corresponding estimated receiving weight matrix W' k .

[0373] Step 704 may include:

[0374] 7041. Terminal device k receives the second signal Perform channel estimation to obtain the second channel estimation matrix corresponding to terminal device k

[0375] Specifically, Since the reference signal The receiving end can know that the terminal device k at the receiving end can obtain an estimate of the equivalent channel

[0376] in, The dimension is According to the second received signal and the second reference signal For H k Δ1 is the estimation error matrix corresponding to the channel estimation.

[0377] For example, the terminal device k may perform channel estimation using an LS channel estimation algorithm or an MMSE channel estimation algorithm.

[0378] 7042. The terminal device k estimates the second channel matrix and receiver type, determine the receiving weight matrix W k The corresponding estimated receiving weight matrix W' k .

[0379] For the specific implementation of step 7042, please refer to the relevant description of step 5042 in the above embodiment, which will not be repeated here.

[0380] The first reference signal and the second reference signal may be demodulation reference signals (DMRSs). DMRS resource 1 corresponding to the first reference signal and DMRS resource 2 corresponding to the second reference signal may occupy different time and frequency resources.

[0381] It should be understood that the terminal device determines the estimated receiving weight matrix W' according to the second transmitted signal. k The scheme is used for illustration only. The present application does not limit the terminal device to only adopting the scheme of steps 705, 706 and 704 to determine the estimated receiving weight matrix W' k In other embodiments, the terminal device k may also determine the receiving weight matrix W corresponding to the terminal device according to the method agreed with the network device. k The corresponding estimated receiving weight matrix W' k .

[0382] The following describes a data signal transmission scheme in a scenario where the dimensionality reduction matrix includes a receiving weight matrix W. Specifically, the data signal transmission method includes:

[0383] 711. The network device performs the following operations according to the first channel matrix: Precoding the transmitted data signal s to obtain a precoded transmitted data signal c;

[0384] The first channel matrix The transmission data signal s=(s1, s2, ..., s n )T The transmitted data signal s can also be understood as the transmitted symbol vector corresponding to the n terminal devices participating in the MIMO transmission, or the multi-user transmitted symbol vector. is the sending symbol vector corresponding to terminal device k.

[0385] s k is the sending symbol vector corresponding to terminal device k, or s k is the data signal sent by terminal device k. k,l (l∈[1,L k ]) represents the data symbol sent by the lth transmission stream corresponding to terminal device k.

[0386] Specifically, the network device is based on the first channel matrix Perform THP precoding on the transmission data signal to obtain a precoded transmission data signal C. The THP precoding includes a nonlinear precoding process and a linear precoding process.

[0387] The process of nonlinear precoding can refer to the relevant description in the signal transmission scheme in the scenario where the dimensionality reduction matrix includes the receiving weight matrix W and the weight matrix V, and will not be repeated here.

[0388] During the linear precoding process, for n terminal devices participating in MIMO transmission, the network device precodes the transmission symbol vector according to the matrix Q to obtain the transmission data signal c corresponding to the n terminal devices. Specifically, the transmission data signal Where β is the power normalization factor.

[0389] The process of the network device performing precoding according to the matrix Q can be understood as a linear processing process.

[0390] 712. The network device sends the precoded transmit data signal c.

[0391] 713. Terminal device k receives the first received data signal

[0392] It can be understood that the received data signals of n terminal devices participating in MIMO transmission

[0393] Among them, the first received data signal is the received data signal corresponding to terminal device k.

[0394] 714. The terminal device k receives the equivalent channel coefficient and the receiving weight matrix W' corresponding to the terminal device k. k Detecting a first received data signal

[0395] Specifically, the terminal device k uses the receiving weight matrix W' corresponding to the terminal device k k , multiplied by the received data signal on the left is Get the second received data signal

[0396] It can be understood that the second received data signals of the n terminal devices participating in the MIMO transmission

[0397] where n represents the corresponding additive noise or interference.

[0398] Matrix G -1 is a diagonal matrix, and the main diagonal element corresponding to the i-th row and i-th column is R H The reciprocal of the main diagonal element corresponding to the i-th row and i-th column of the matrix. The second received data signal corresponding to the terminal device k can be expressed as Represents the symbol vector sent after the modular operation corresponding to the terminal device k.

[0399] I understand. In the matrix, the m main diagonal elements corresponding to terminal device k are the equivalent channel coefficients corresponding to the m transmission streams of terminal device k. The terminal device can use the equivalent channel coefficients obtained in step 705 to detect the received data signal and obtain an estimation result of the transmitted data signal.

[0400] Among them, based on the above The implementation method is to obtain the equivalent channel matrix R based on the first received signal H , where R H The elements on the main diagonal in each row correspond to the equivalent channel coefficients of a transmission stream. The equivalent channel coefficients obtained based on the first received signal for the u-th spatial layer of terminal device k are

[0401] is a matrix The elements on the main diagonal in the row corresponding to the u-th spatial layer of terminal device k. The sum modulo operation can estimate the data signal sent by the u-th spatial layer of the terminal device k. The implementation method is to obtain an equivalent channel matrix based on the first received signal Based on the equivalent channel matrix The sum-modulus operation can be used to estimate the data signal corresponding to the terminal device k.

[0402] The present application also provides a signal transmission device. Figure 8The structural schematic diagram of the signal transmission device shown in the figure, the signal transmission device 800 includes a receiving unit 801 and a processing unit 802; the signal transmission device can be, for example, a terminal device, or the signal transmission device is deployed in the terminal device; the receiving unit 801 is used to receive a first received signal; the first received signal is sent to the terminal device via the downlink channel corresponding to the terminal device after precoding the first reference signal according to the first channel matrix, the first channel matrix is ​​obtained according to the second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in MIMO transmission, and the second channel matrix is ​​the channel matrix of the downlink channel corresponding to one or more terminal devices; the processing unit 802 is used to obtain the equivalent channel coefficient corresponding to the terminal device according to the first received signal.

[0403] According to the technical solution of an embodiment of the present application, a first received signal is sent to a terminal device via a downlink channel corresponding to the terminal device after precoding a first reference signal according to a first channel matrix. The first channel matrix is ​​obtained according to a second channel matrix. The number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of n terminal devices participating in MIMO transmission. This can reduce the difficulty of matrix calculation during THP precoding, making the THP precoding calculation simpler.

[0404] In some embodiments, the first channel matrix W is the receiving weight matrix, V is the weight matrix, H is the second channel matrix, and the number of rows of the receiving weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in MIMO transmission.

[0405] Optionally, the number of rows of the receiving weight matrix is ​​the sum of the number of transmission streams of one or more terminal devices, and / or the number of columns of the weight matrix is ​​the sum of the number of transmission streams of multiple terminal devices.

[0406] In some possible implementations, the receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; the receiving unit 801 is further configured to receive a second receive signal;

[0407] The processing unit 802 is further configured to:

[0408] Obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes:

[0409] Determine an estimated receiving weight matrix corresponding to the receiving weight matrix according to the second received signal; and

[0410] An equivalent channel coefficient corresponding to the terminal device is obtained according to the estimated receiving weight matrix and the first received signal.

[0411] Optionally, the weight matrix includes a weight sub-matrix corresponding to the terminal device, and the second received signal is sent to the terminal device through a downlink channel corresponding to the terminal device after the network device precodes the second reference signal according to the weight sub-matrix.

[0412] In some embodiments, the first channel matrix W is a receiving weight matrix, and the number of rows of the receiving weight matrix is ​​less than the sum of the number of receiving antennas of one or more terminal devices participating in the MIMO transmission.

[0413] Optionally, the number of rows of the receiving weight matrix is ​​the sum of the number of transmission streams of multiple terminal devices.

[0414] In some possible implementations, the receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; the receiving unit 801 is further configured to receive a second receive signal;

[0415] The processing unit 802 is further configured to:

[0416] Obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes:

[0417] Determine an estimated receiving weight matrix corresponding to the receiving weight matrix according to the second received signal; and

[0418] An equivalent channel coefficient corresponding to the terminal device is obtained according to the estimated receiving weight matrix and the first received signal.

[0419] In some embodiments, the receiving unit 801 is also used to receive a first received data signal, which is sent to the terminal device through the downlink channel corresponding to the terminal device after the network device pre-encodes the sent data signal according to the first channel matrix; the processing unit 802 is also used to detect the first received data signal based on the estimated receiving weight matrix and the equivalent channel coefficient corresponding to the terminal device.

[0420] In some embodiments, in detecting the data signal based on the estimated receiving weight matrix and the equivalent channel coefficient corresponding to the terminal device, the processing unit 802 is specifically configured to:

[0421] Multiplying the first received data signal by the estimated receiving weight matrix on the left to obtain a second received data signal corresponding to the first received data signal;

[0422] An estimation result of the transmitted data signal is obtained based on the second received data signal and the equivalent channel coefficient corresponding to the terminal device.

[0423] Optionally, the signal transmission device 800 further includes a sending unit, configured to send a receiver type of the terminal device, where the receiver type of the terminal device is used by the network device to determine a receiving weight matrix.

[0424] It should be understood that the technical effects and related supplementary explanations of the various embodiments of the above-mentioned signal transmission method are also applicable to the signal transmission device 800 of the embodiment of the present application, and will not be repeated here.

[0425] The present application also provides a signal transmission device for multiple-input multiple-output MIMO transmission, such as Figure 9 The structural diagram of the signal transmission device shown in the figure, the signal transmission device 900 includes a processing unit 901 and a sending unit 902; the signal transmission device 900 can be, for example, a network device, or the signal transmission device can be deployed in a network device; wherein the processing unit 901 is used to precode the first reference signal according to the first channel matrix to obtain a first transmission signal, the first channel matrix is ​​obtained according to the second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in the MIMO transmission, and the second channel matrix is ​​the channel matrix of the downlink channel of one or more terminal devices; the sending unit 902 is used to send the first transmission signal.

[0426] According to the technical solution of the present application, a signal transmission device precodes a first reference signal according to a first channel matrix, the first channel matrix is ​​obtained according to a second channel matrix, and the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receiving antennas of n terminal devices participating in the MIMO transmission, thereby reducing the difficulty of matrix calculation during the THP precoding process, making the THP precoding calculation simpler.

[0427] In some embodiments, the first channel matrix W is a receiving weight matrix, V is a weight matrix, and the number of rows of the receiving weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices.

[0428] Optionally, the number of rows of the receiving weight matrix is ​​the sum of the number of transmission streams of one or more terminal devices, and / or the number of columns of the weight matrix is ​​the number of transmission streams of one or more terminal devices.

[0429] Optionally, the weight matrix includes a weight sub-matrix corresponding to each terminal device in one or more terminal devices, and the weight sub-matrix corresponding to each terminal device is determined according to the channel matrix of the downlink channel corresponding to the terminal device.

[0430] In a possible implementation, the sending unit 902 is further configured to send a second sending signal, where each terminal device in the one or more terminal devices determines an estimated receiving weight matrix corresponding to its own receiving weight matrix.

[0431] Optionally, the second transmit signal is obtained by the network device precoding the second reference signal according to the weight sub-matrix.

[0432] In some embodiments, the first channel matrix W is a receiving weight matrix, and the number of rows of the receiving weight matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices.

[0433] Optionally, the received weight matrix includes a receiving weight sub-matrix corresponding to each terminal device among multiple terminal devices, and the receiving weight sub-matrix corresponding to each terminal device is determined by the network device according to the receiver type of the terminal device.

[0434] Optionally, the processing unit 901 is further used to precode the transmit data signal according to the first channel matrix to obtain a precoded transmit data signal; and the transmitting unit is further used to send the precoded transmit data signal.

[0435] It should be understood that the technical effects and related supplementary explanations of the various embodiments of the above-mentioned signal transmission method are also applicable to the signal transmission device 900 of the embodiment of the present application, and will not be repeated here.

[0436] The present application provides a computer program product, which includes: a computer program (also referred to as code, or instructions), which, when executed, enables a computer to execute the steps that can be executed by a network device in any of the above method embodiments or to execute the steps that can be executed by a terminal device in any of the above method embodiments.

[0437] The present application provides a computer-readable storage medium, which stores a computer program (also referred to as code, or instructions). When the computer-readable storage medium is run on a computer, the computer executes the steps that can be executed by a network device in any of the above method embodiments or executes the steps that can be executed by a terminal device in any of the above method embodiments.

[0438] It should also be understood that the first, second, third, fourth and various numerical numbers involved in this document are only distinctions for convenience of description and are not intended to limit the scope of this application.

[0439] It should be understood that the term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0440] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0441] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0442] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0443] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0444] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0445] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0446] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0447] The steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs.

[0448] The modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0449] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A signal transmission method for multiple-input multiple-output (MIMO) transmission, characterized in that: include: The terminal device receives a first reception signal; The first received signal is sent to the terminal device via a downlink channel corresponding to the terminal device after precoding a first reference signal according to a first channel matrix, the first channel matrix is ​​obtained according to a second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receive antennas of one or more terminal devices participating in MIMO transmission, and the second channel matrix is ​​a channel matrix of a downlink channel corresponding to the one or more terminal devices; The terminal device obtains the equivalent channel coefficient corresponding to the terminal device based on the first received signal.

2. The method according to claim 1, characterized in that The first channel matrix W is the receiving weight matrix, V is the weight matrix, H is the second channel matrix, and the number of rows of the receiving weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of one or more terminal devices participating in the MIMO transmission.

3. The method according to claim 2, characterized in that The number of rows of the reception weight matrix is ​​the sum of the number of transmission streams of the one or more terminal devices, and / or the number of columns of the weight matrix is ​​the sum of the number of transmission streams of the multiple terminal devices.

4. The method according to claim 2, characterized in that The receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; The method further comprises: The terminal device receives a second reception signal; The terminal device obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes: The terminal device determines, according to the second received signal, an estimated receiving weight submatrix corresponding to the receiving weight submatrix; The terminal device obtains the equivalent channel coefficient corresponding to the terminal device based on the estimated receiving weight matrix and the first received signal.

5. The method according to claim 4, characterized in that The weight matrix includes a weight sub-matrix corresponding to the terminal device, and the second received signal is sent to the terminal device through the downlink channel corresponding to the terminal device after the network device precodes the second reference signal according to the weight sub-matrix.

6. The method according to claim 1, wherein the first channel matrix W is a receiving weight matrix, H is the second channel matrix, and the number of rows of the receiving weight matrix is ​​less than the sum of the number of receiving antennas of the one or more terminal devices participating in the MIMO transmission.

7. The method according to claim 6, characterized in that The number of rows of the receiving weight matrix is ​​the sum of the number of transmission streams of the multiple terminal devices.

8. The method according to claim 6, characterized in that The receiving weight matrix includes a receiving weight sub-matrix corresponding to the terminal device; The method further comprises: The terminal device receives a second reception signal; The terminal device obtaining, according to the first received signal, an equivalent channel coefficient corresponding to the terminal device includes: The terminal device determines, according to the second received signal, an estimated receiving weight submatrix corresponding to the receiving weight submatrix; The terminal device obtains the equivalent channel coefficient corresponding to the terminal device based on the estimated receiving weight matrix and the first received signal.

9. The method according to claim 4 or 8, characterized in that The method further comprises: The terminal device receives a first received data signal, where the first received data signal is sent to the terminal device via a downlink channel corresponding to the terminal device after the network device precodes the transmitted data signal according to the first channel matrix; The terminal device detects the first received data signal based on the estimated receiving weight matrix and the equivalent channel coefficient corresponding to the terminal device.

10. The method according to claim 9, characterized in that The terminal device detecting the first received data signal according to the estimated receiving weight matrix and the equivalent channel coefficient corresponding to the terminal device includes: The terminal device multiplies the first received data signal by the estimated receiving weight matrix to obtain a second received data signal corresponding to the first received data signal; The terminal device obtains an estimation result of the transmitted data signal based on the second received data signal and the equivalent channel coefficient corresponding to the terminal device.

11. The method according to claim 2, characterized in that The method further comprises: The terminal device sends the receiver type of the terminal device, and the receiver type of the terminal device is used by the network device to determine the receiving weight matrix.

12. A signal transmission method for multiple-input multiple-output (MIMO) transmission, characterized in that: include: The network device precodes the first reference signal according to a first channel matrix to obtain a first transmit signal, where the first channel matrix is ​​obtained according to a second channel matrix, the number of rows and / or columns of the first channel matrix is ​​less than or equal to the sum of the number of receive antennas of one or more terminal devices participating in MIMO transmission, and the second channel matrix is ​​a channel matrix of a downlink channel of the one or more terminal devices; The network device sends the first transmission signal.

13. The method according to claim 12, characterized in that The first channel matrix W is the receiving weight matrix, V is the weight matrix, H is the second channel matrix, and the number of rows of the receiving weight matrix and / or the number of columns of the weight matrix is ​​less than or equal to the sum of the number of receiving antennas of the one or more terminal devices.

14. The method according to claim 13, characterized in that The number of rows of the reception weight matrix is ​​the sum of the number of transmission streams of the one or more terminal devices, and / or the number of columns of the weight matrix is ​​the number of transmission streams of the one or more terminal devices.

15. The method according to claim 13 or 14, characterized in that The weight matrix includes a weight sub-matrix corresponding to each terminal device in the one or more terminal devices, and the weight sub-matrix corresponding to each terminal device is determined according to the channel matrix of the downlink channel corresponding to the terminal device.

16. The method according to claim 15, characterized in that The method further comprises: The network device sends a second transmission signal, where the second transmission signal is used for each of the one or more terminal devices to determine an estimated receiving weight submatrix corresponding to its corresponding receiving weight submatrix.

17. The method according to claim 16, characterized in that The second transmission signal is obtained by the network device precoding a second reference signal according to the weight sub-matrix.

18. The method according to claim 12, characterized in that The first channel matrix W is the receiving weight matrix, H is the second channel matrix, and the number of rows of the receiving weight matrix is ​​less than or equal to the sum of the number of receiving antennas of the one or more terminal devices.

19. The method according to claim 13, wherein The receiving weight matrix includes a receiving weight sub-matrix corresponding to each terminal device among the multiple terminal devices. The receiving weight sub-matrix corresponding to each terminal device is determined by the network device according to the receiver type of the terminal device.

20. The method according to claim 12, wherein The method further comprises: The network device precodes the transmit data signal according to the first channel matrix to obtain a precoded transmit data signal; The network device sends the precoded transmission data signal.

21. A communication device, characterized in that: The communication device comprises a processor and a memory, wherein the memory is used to store computer instructions, and the processor executes the computer instructions, so that the communication device executes the method according to any one of claims 1 to 11, or the communication device executes the method according to any one of claims 12 to 20.

22. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions instruct the communication device to execute the method according to any one of claims 1 to 11 or the method according to any one of claims 12 to 20.

23. A chip, characterized in that: include: A processor and an interface, configured to execute a computer program or instruction stored in a memory, and to execute the method according to any one of claims 1 to 11 or the method according to any one of claims 12 to 20.

24. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is run on a computer, the computer is caused to perform the method according to any one of claims 1 to 11 or the method according to any one of claims 12 to 20.

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