A communication method, terminal and base station

Abstract

The present application discloses a communication method, a terminal and a base station, the method comprising: the terminal receives indication information sent by the base station, indicating the precoding matrix included in the first precoding matrix set and the transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data stream on r transmission layers to obtain the signal sent on N transmission ports of the terminal; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of the r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1; the terminal determines the precoding matrix for precoding the transmission data stream according to the indication information. The precoding matrix with rank>1 is spliced ​​by the precoding matrix with rank=1, which can reduce the implementation complexity of the terminal and ensure a smaller downlink signaling indication overhead and better transmission performance.

Description

Technical Field

[0001] The present application relates to the field of mobile communication technology, and in particular to a communication method, a terminal and a base station. Background Art

[0002] In the discussion of the New Radio access technology (NR) of the 3rd generation partnership project (3GPP), uplink multi-antenna transmission is currently confirmed to be supported. The mechanism of uplink multi-antenna transmission is similar to that of downlink. The terminal first sends a sounding reference signal (SRS). The base station receives the SRS and obtains the uplink channel state through channel estimation, and then schedules the uplink transmission by sending downlink control information (DCI). Based on the conclusions of the current NR discussion, up to 4 uplink SRS ports can be supported. In addition, considering the case of uplink transmission based on the codebook, when the base station instructs the terminal to transmit uplink, it can use a predefined codebook to indicate the precoding matrix of the uplink multi-antenna transmission. Specifically, this codebook includes N optional precoding matrices. Based on the SRS sent by the terminal, the base station selects one from the N precoding matrices and determines it as the precoding matrix to be used on these SRS ports, and sends a precoding matrix indication (transmit precoding matrix indication, TPMI) to indicate the precoding matrix to be used on these SRS ports. After receiving the DCI for uplink scheduling, the terminal learns the precoding matrix required for uplink transmission by reading the indication bit of the TPMI.

[0003] In LTE-A (long term evolution-advanced), the uplink codebook based on the single-carrier transform spread wavelength division multiplexing (discrete fourier transform spread orthogonal frequency divided multiplexing, DFT-S-OFDM) waveform is greatly limited by the low peak-to-average ratio limit of the DFT-S-OFDM single-carrier waveform. In order to meet the low peak-to-average ratio requirement, the precoding matrix spacing of the precoding matrix with rank>1 has the disadvantage of unevenness. Since the NR uplink transmission is determined to use the cyclic prefix-based wavelength division multiplexing (cyclic prefixed orthogonal frequency divided multiplexing, CP-OFDM) waveform when the rank>1, it is no longer subject to the low peak-to-average ratio limit. At this time, directly using the LTE-A precoding matrix with rank>1 will result in performance loss. Based on the above uplink codebook, improvements are made, and multiple port groupings are considered. The uplink codebook design for generating precoding matrices based on different port groupings includes 64 or 128 precoding matrices for rank=1, and 64 or 128 precoding matrices for rank=2. This uplink codebook design is too large, and generating precoding matrices based on different port groupings increases the complexity of the standard, the complexity and overhead of implementation, and is not the best solution.

[0004] In summary, in order to determine the need to use CP-OFDM waveform for NR uplink transmission when rank>1, it is necessary to design a concise and universal codebook. Summary of the invention

[0005] The present application provides a communication method, a terminal and a base station to meet the above requirements.

[0006] In a first aspect, the present application provides a communication method, the method comprising:

[0007] The terminal receives indication information sent by the base station, the indication information includes a first bit field, the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data streams on r transmission layers to obtain signals sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1; the terminal determines the precoding matrix for precoding the transmission data streams on all transmission layers according to the indication information.

[0008] In one possible design, coherent transmission can be performed between the transmission ports;

[0009] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset include 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different;

[0010] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, wherein a non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0011] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0012] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0013] In one possible design, the third precoding matrix subset includes any two or three of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix; wherein the beam space of the first column and the second column of the first type of precoding matrix are exactly the same, but the cross-polarization phases are different; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are the same; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0014] In one possible design, the transmission ports are divided into a first port group and a second port group, and coherent transmission can be performed between the transmission ports. Coherent transmission can be performed within the first port group, within the second port group, and between the first port group and the second port group.

[0015] In a possible design, the transmission ports are divided into a first port group and a second port group, coherent transmission can be performed within the first port group and within the second port group, but coherent transmission cannot be performed between the first port group and the second port group;

[0016] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset include 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, and the rows where the 1 non-zero element in each of the 4 precoding matrices is located are different;

[0017] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset;

[0018] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset;

[0019] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0020] In one possible design, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset including a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the rows of the first precoding matrix containing non-zero elements correspond to transmission ports included in the first port group; the rows of the second precoding matrix containing non-zero elements correspond to transmission ports included in the second port group.

[0021] In a possible design, coherent transmission cannot be performed between the transmission ports;

[0022] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, and the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements; the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different; the transmission power of the transmission port corresponding to the row containing the zero element is 0;

[0023] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset;

[0024] All precoding matrices of transmission rank 3 include a tenth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset;

[0025] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0026] In one possible design, when coherent transmission is possible between the transmission ports, the first bit field occupies 7 bits or 6 bits.

[0027] In a possible design, when coherent transmission is possible within the first port group and within the second port group, but coherent transmission is not possible between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits.

[0028] In one possible design, when coherent transmission is not possible between the transmission ports, the first bit field occupies 4 bits.

[0029] In a possible design, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, -j.

[0030] In one possible design, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0031] In a possible design, the two transmission ports included in the first port group correspond to a dual-polarization antenna pair, or the two transmission ports included in the first port group correspond to two beams with the same beam direction but perpendicular polarization directions.

[0032] In a second aspect, the present application provides a communication method, comprising: a base station determines indication information, the indication information comprising a first bit field, the first bit field being used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix being used to precode a transmission data stream on r transmission layers to obtain a signal sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1; the base station sends the indication information to the terminal, and the indication information is used to enable the terminal to determine the precoding matrix for precoding the transmission data streams on all transmission layers.

[0033] In one possible design, coherent transmission can be performed between the transmission ports;

[0034] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset include 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different;

[0035] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, wherein a non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0036] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0037] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0038] In one possible design, the third precoding matrix subset includes any two or three of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix; wherein the beam space of the first column and the second column of the first type of precoding matrix are exactly the same, but the cross-polarization phases are different; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are the same; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0039] In one possible design, the transmission ports are divided into a first port group and a second port group, and coherent transmission can be performed between the transmission ports. Coherent transmission can be performed within the first port group, within the second port group, and between the first port group and the second port group.

[0040] In a possible design, the transmission ports are divided into a first port group and a second port group, coherent transmission can be performed within the first port group and within the second port group, and coherent transmission cannot be performed between the first port group and the second port group;

[0041] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset include 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, and the rows where the 1 non-zero element in each of the 4 precoding matrices is located are different;

[0042] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset;

[0043] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset;

[0044] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0045] In one possible design, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset including a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the rows of the first precoding matrix containing non-zero elements correspond to transmission ports included in the first port group; the rows of the second precoding matrix containing non-zero elements correspond to transmission ports included in the second port group.

[0046] In a possible design, coherent transmission cannot be performed between the transmission ports;

[0047] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, and the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements; the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different; the transmission power of the transmission port corresponding to the row containing the zero element is 0;

[0048] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset;

[0049] All precoding matrices of transmission rank 3 include a tenth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset;

[0050] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0051] In one possible design, when coherent transmission is possible between the transmission ports, the first bit field occupies 7 bits or 6 bits.

[0052] In a possible design, when coherent transmission is possible within the first port group and within the second port group but coherent transmission is not possible between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits.

[0053] In one possible design, when coherent transmission is not possible between the transmission ports, the first bit field occupies 4 bits.

[0054] In a possible design, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, -j.

[0055] In one possible design, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0056] In a possible design, the two transmission ports included in the first port group correspond to a dual-polarization antenna pair, or the two transmission ports included in the first port group correspond to two beams with the same beam direction but perpendicular polarization directions.

[0057] In a third aspect, the present application provides a terminal, including a processor and a communication interface, wherein the processor is configured to support a base station to perform the corresponding functions of the base station in the above method. The communication interface is used to support communication between the terminal and the base station to send information or instructions involved in the above method to the base station. The terminal may also include a memory, which is coupled to the processor and stores program instructions and data necessary for the base station.

[0058] The communication interface is used to receive indication information from the base station, the indication information includes a first bit field, the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data stream on r transmission layers to obtain a signal sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1;

[0059] The processor is used to determine, according to the indication information, the precoding matrix for precoding the transmission data streams on all transmission layers.

[0060] In one possible design, coherent transmission can be performed between the transmission ports;

[0061] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset include 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different;

[0062] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, wherein a non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0063] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0064] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0065] In one possible design, the third precoding matrix subset includes any two or three of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix; wherein the beam space of the first column and the second column of the first type of precoding matrix are exactly the same, but the cross-polarization phases are different; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are the same; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0066] In one possible design, the transmission ports are divided into a first port group and a second port group, and coherent transmission can be performed between the transmission ports. Coherent transmission can be performed within the first port group, within the second port group, and between the first port group and the second port group.

[0067] In a possible design, the transmission ports are divided into a first port group and a second port group, coherent transmission can be performed within the first port group and within the second port group, and coherent transmission cannot be performed between the first port group and the second port group;

[0068] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset include 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, and the rows where the 1 non-zero element in each of the 4 precoding matrices is located are different;

[0069] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset;

[0070] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset;

[0071] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0072] In one possible design, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset including a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the rows of the first precoding matrix containing non-zero elements correspond to transmission ports included in the first port group; the rows of the second precoding matrix containing non-zero elements correspond to transmission ports included in the second port group.

[0073] In a possible design, coherent transmission cannot be performed between the transmission ports;

[0074] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, and the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements; the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different; the transmission power of the transmission port corresponding to the row containing the zero element is 0;

[0075] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset;

[0076] All precoding matrices of transmission rank 3 include a tenth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset;

[0077] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0078] In one possible design, when coherent transmission is possible between the transmission ports, the first bit field occupies 7 bits or 6 bits.

[0079] In a possible design, when coherent transmission is possible within the first port group and within the second port group but coherent transmission is not possible between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits.

[0080] In one possible design, when coherent transmission is not possible between the transmission ports, the first bit field occupies 4 bits.

[0081] In a possible design, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, -j.

[0082] In one possible design, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0083] In a possible design, the two transmission ports included in the first port group correspond to a dual-polarization antenna pair, or the two transmission ports included in the first port group correspond to two beams with the same beam direction but perpendicular polarization directions.

[0084] In a fourth aspect, the present application provides a base station, comprising a processor and a communication interface, wherein the processor is configured to support the base station to perform the corresponding functions of the base station in the above method. The communication interface is used to support communication between the base station and the terminal to send information or instructions involved in the above method to the terminal. The base station may also include a memory, which is coupled to the processor and stores program instructions and data necessary for the base station.

[0085] The processor is used to determine indication information, the indication information includes a first bit field, the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data stream on r transmission layers to obtain a signal sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1; the communication interface is used to send indication information to the terminal, the indication information is used to enable the terminal to determine the precoding matrix for precoding the transmission data stream on all transmission layers.

[0086] In one possible design, coherent transmission can be performed between the transmission ports;

[0087] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset include 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different;

[0088] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, wherein a non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0089] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0090] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0091] In one possible design, the third precoding matrix subset includes any two or three of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix; wherein the beam space of the first column and the second column of the first type of precoding matrix are exactly the same, but the cross-polarization phases are different; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are the same; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0092] In one possible design, the transmission ports are divided into a first port group and a second port group, and coherent transmission can be performed between the transmission ports. Coherent transmission can be performed within the first port group, within the second port group, and between the first port group and the second port group.

[0093] In a possible design, the transmission ports are divided into a first port group and a second port group, coherent transmission can be performed within the first port group and within the second port group, and coherent transmission cannot be performed between the first port group and the second port group;

[0094] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset include 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, and the rows where the 1 non-zero element in each of the 4 precoding matrices is located are different;

[0095] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset;

[0096] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset;

[0097] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0098] In one possible design, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset including a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the rows of the first precoding matrix containing non-zero elements correspond to transmission ports included in the first port group; the rows of the second precoding matrix containing non-zero elements correspond to transmission ports included in the second port group.

[0099] In a possible design, coherent transmission cannot be performed between the transmission ports;

[0100] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, and the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements; the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different; the transmission power of the transmission port corresponding to the row containing the zero element is 0;

[0101] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset;

[0102] All precoding matrices of transmission rank 3 include a tenth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset;

[0103] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0104] In one possible design, when coherent transmission is possible between the transmission ports, the first bit field occupies 7 bits or 6 bits.

[0105] In a possible design, when coherent transmission is possible within the first port group and within the second port group but coherent transmission is not possible between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits.

[0106] In one possible design, when coherent transmission is not possible between the transmission ports, the first bit field occupies 4 bits.

[0107] In a possible design, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, -j.

[0108] In one possible design, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0109] In a possible design, the two transmission ports included in the first port group correspond to a dual-polarization antenna pair, or the two transmission ports included in the first port group correspond to two beams with the same beam direction but perpendicular polarization directions.

[0110] In a fifth aspect, in order to achieve the above-mentioned purpose of the invention, the present application provides a circuit system, which includes an interface unit, a control and computing unit, and a storage unit, the interface unit is used to connect with other components of the base station or the terminal, the storage unit is used to store computer programs or instructions, and the control and computing unit is used to decode and execute these computer programs or instructions; when these computer programs or instructions are executed, they are used to implement the above-mentioned first aspect or any possible implementation of the first aspect, or, to implement the above-mentioned second aspect or any possible implementation of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] Figure 1 A schematic diagram of the architecture of a wireless communication system provided by the present application;

[0112] Figure 2 A schematic diagram of a dual-polarized antenna pair assumed for this application;

[0113] Figure 3 A schematic diagram of the structure of a device provided in this application;

[0114] Figure 4 A schematic diagram of the structure of another device provided in this application;

[0115] Figure 5 A schematic diagram of the structure of a circuit system provided in this application;

[0116] Figure 6 A schematic diagram of the structure of another circuit system provided for this application;

[0117] Figure 7 A method flow chart of a communication method provided in this application. DETAILED DESCRIPTION

[0118] The present application will be described in further detail below in conjunction with the accompanying drawings.

[0119] The system operating environment of the present application is introduced below. The technology described in the present application can be applicable to LTE systems, such as LTE / LTE-A / eLTE systems, or other wireless communication systems that adopt various wireless access technologies, such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other access technologies. The system is also applicable to subsequent evolution systems, such as the fifth generation 5G (also known as new radio (NR)) system, etc., and can also be expanded to similar wireless communication systems, such as WiFi, WiMAX, and 3GPP-related cellular systems.

[0120] Figure 1 A schematic diagram of a communication system is given. The communication system may include at least one base station 100 (only one is shown) and one or more terminals 200 connected to the base station 100.

[0121] The base station 100 may be a device that can communicate with the terminal 200. The base station 100 may be any device with wireless transceiver functions. Including but not limited to: base station NodeB, evolved base station eNodeB, base station in the fifth generation (5G) communication system, base station or base station in the future communication system, access node in WiFi system, wireless relay node, wireless backhaul node, etc. The base station 100 may also be a wireless controller in the cloud radio access network (CRAN) scenario. The base station 100 may also be a base station in a 5G network or a base station in a future evolution network; it may also be a wearable device or a vehicle-mounted device, etc. The base station 100 may also be a small station, a transmission reference point (TRP), etc. Of course, the application is not limited to this.

[0122] The terminal 200 is a device with wireless transceiver function that can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The embodiments of the present application do not limit the application scenario. The terminal may sometimes also be referred to as user equipment (UE), access terminal, UE unit, UE station, mobile station, mobile station, remote station, remote terminal, mobile device, UE terminal, terminal, wireless communication equipment, UE agent or UE device, etc.

[0123] It should be noted that the terms "system" and "network" in the embodiments of the present invention can be used interchangeably. "Multiple" refers to two or more than two. In view of this, "multiple" can also be understood as "at least two" in the embodiments of the present invention. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the previous and subsequent associated objects are in an "or" relationship. In this application, "TPMI" and "precoding matrix number" can be used interchangeably, "TRI" and "number of transmission ranks" can be used interchangeably, "transmission rank" and "rank" can be used interchangeably, and "transmission data stream" and "transmission data stream" can be used interchangeably.

[0124] Multiple-input multiple-output (MIMO) technology uses multiple antennas to send multiple data paths in parallel, thereby obtaining additional spatial multiplexing gain. In order to better utilize the complex spatial characteristics of the channel, the transmitted data stream is generally precoded, and the signal is preprocessed at the transmitting end using the channel state information to improve the signal transmission quality.

[0125] In precoding technology, the received vector can be expressed as y=HWx+n, where H represents the spatial channel matrix, W is the precoding matrix, x is the transmitted signal vector, and n is the noise vector. The precoding matrix W is I×N 层 matrix. I is the number of transmission ports, N 层 is the number of symbol streams, generally referred to as the transmission rank or the number of transmission layers. The precoding matrix W can transform N 层 The data streams of the transport layers are pre-coded and mapped to I transmission ports, and N 层 ≤I. The selection of W is generally based on a codebook, that is, a set of precoding matrices. The codebook is recorded in the communication standard and is known to both the sender and the receiver of the wireless communication. By indicating the index of a matrix in the codebook in the signaling, the corresponding precoding matrix information of the receiver or the sender can be indicated. Generally speaking, in multi-antenna wireless communications, by selecting the precoding matrix W, the multi-antenna channel capacity can be maximized, or the bit error rate can be minimized based on a certain demodulation algorithm.

[0126] In LTE-A, uplink MIMO technology is introduced. In the uplink MIMO system of LTE-A, the terminal can be configured with 2 or 4 transmission ports. When transmitting data in the uplink of LTE-A, a single codebook is used to precode the data stream.

[0127] Figure 2 A dual-polarization array of 4 transmission ports of the terminal, wherein port 1 and port 3 belong to the same dual-polarization antenna pair, and port 2 and port 4 belong to the same dual-polarization antenna pair. Port 1 and port 2 represent the same polarization direction, and port 3 and port 4 represent the same polarization direction.

[0128] based on Figure 2 The dual-polarization array shown, an uplink codebook design criteria for using a DFT-S-OFDM waveform in LTE-A is as follows:

[0129] When the number of transmission data streams is 1, that is, the rank is 1, the port merging precoding matrix is ​​generated based on the mutually unbiased bases (MUB) of the 4-dimensional complex space, that is, the precoding matrix corresponding to the sequence numbers 0-15 in Table 1. Specifically, the precoding matrices with sequence numbers 0, 2, 8, and 10 correspond to an orthogonal basis, the precoding matrices with sequence numbers 1, 3, 9, and 11 correspond to an orthogonal basis, the precoding matrices with sequence numbers 4, 6, 12, and 14 correspond to an orthogonal basis, and the precoding matrices with sequence numbers 5, 7, 13, and 15 correspond to an orthogonal basis. The function indicated by the precoding matrix corresponding to sequence numbers 16-23 in Table 1 is: when any dual-polarized antenna pair is blocked, the corresponding port can be selected to be closed, and the transmission power on the port is 0 at this time.

[0130] When the number of transmission data streams is 2, that is, the rank is 2, in order to maintain the single carrier characteristics, the precoding matrix of the 4-port merger is no longer used to generate the precoding corresponding to each transmission layer, but two corresponding transmission ports are selected for each transmission data stream, and it is ensured that any port is not used for two data streams at the same time. Specifically, for the case where the two transmission layers correspond to two beams with different polarization directions, a combination method of dual-polarized antenna pairs is adopted in which port 1 and port 2 are merged into one port group, and port 3 and port 4 are merged into another port group, and beam quantization corresponding to the binary phase shift keying (BPSK) phase is defined, and the quadriphase shift keying (QPSK) phase is adopted, and 8 precoding matrices are used, and the precoding matrices corresponding to the serial numbers 0-7 in Table 2 are obtained. Correspondingly, a combination method of dual-polarized antenna pairs is adopted in which port 1 and port 3 are merged into one port group, and port 2 and port 4 are merged into another port group, and the precoding matrices corresponding to the serial numbers 8-11 in Table 2 are obtained. Accordingly, a combination of dual-polarized antenna pairs in which port 1 and port 4 are combined into one port group and port 2 and port 3 are combined into another port group is adopted to obtain the precoding matrix corresponding to sequence numbers 12-15 in Table 2.

[0131] When the number of transmission data streams is 3, that is, the rank is 3, in order to maintain the single-carrier characteristics, a similar criterion is adopted. Each transmission data stream selects the corresponding transmission port, and it is ensured that any port is not used for two data streams at the same time. Considering that the order of the transmission data stream does not affect the decoding characteristics, only the first data stream (i.e., the first column of the precoding matrix) is designed to use 2 transmission ports. In addition, considering that the gain brought by more accurate port merging is not large when the rank is 3, only the BPSK phase is used.

[0132] When the number of transmission data streams is 4, that is, the rank is 4, only each transmission data stream corresponds to one transmission port.

[0133] Based on DFT-S-OFDM, the design of the LTE-A uplink codebook when the number of transmission data streams is 1 is shown in Table 1, the design of the LTE-A uplink codebook when the number of transmission data streams is 2 is shown in Table 2, the design of the LTE-A uplink codebook when the number of transmission data streams is 3 is shown in Table 3, and the design of the LTE-A uplink codebook when the number of transmission data streams is 4 is shown in Table 4.

[0134] Table 1

[0135]

[0136] Table 2

[0137]

[0138] Table 3

[0139]

[0140] Table 4

[0141]

[0142] The uplink codebook design in the above LTE-A is greatly limited by the low peak-to-average ratio limit of the DFT-S-OFDM single-carrier waveform. In order to meet the low peak-to-average ratio requirement, when the rank>1, some precoding matrix spacing is sacrificed, that is, the uniformity and density of the precoding matrix sampling the G(4,n)-dimensional Grassmanian complex space are sacrificed. Since the NR uplink transmission is determined to use the CP-OFDM waveform when the rank>1, it is no longer subject to the low peak-to-average ratio limit. At this time, directly using the LTE-A precoding matrix with a rank>1 will result in performance loss.

[0143] based on Figure 2 The dual-polarization array shown, an uplink codebook design criteria for using a DFT-S-OFDM waveform in NR is as follows:

[0144] For the uniform linear array (ULA) array, a precoding matrix with rank>1 is constructed based on the MUB basis used by the precoding matrix with rank=1 in the LTE-A codebook. If the spatial chordal distance between two precoding matrices is 0, there is no need to put the two precoding matrices into the codebook at the same time. Based on such a design criterion, a large codebook based on 8PSK phase can be obtained, which can regard the existing codebook as its subset. Its rank=1 precoding matrix includes a total of 64 or 128 precoding matrices, and its rank=2 precoding matrix also has 64 or 128. Through the configuration of the code book subset restriction (CBSR), a different codebook subset can be configured for each user to reduce the TPMI indication signaling overhead in the downlink control information (DCI).

[0145] However, this uplink codebook is designed to be too large. The use of 8PSK may not be suitable for terminals with lower modulation capabilities. In addition, the MTK codebook design takes into account multiple port groupings, and generates precoding matrices based on different port groupings. In fact, the order of ports can be solved by reinterpreting the antenna ports in the implementation. There are many similar redundant designs. The large codebook based on such design criteria increases the complexity of the standard. It seems to increase the flexibility of implementation, but in fact it increases the complexity and overhead of implementation, and is not the best solution. For example, the above design needs to configure the codebook subset based on CBSR. Based on the redundant design, the overhead of RRC configuration is inevitable.

[0146] In view of the shortcomings of the above two uplink codebook designs, the present application provides a design of an uplink codebook using a CP-OFDM waveform applied in NR, aiming to design a concise and universal codebook. The design ideas of the uplink codebook provided in the present application are as follows:

[0147] First, this application Figure 2 The explanations for the dual polarized antenna pair shown are as follows:

[0148] Based on the consideration of the antenna array elements corresponding to the transmission port, such as Figure 2 As shown, ports 1 and 2 can be regarded as antenna elements or transmit radio frequency units (TXRU) with the same or similar polarization directions, and ports 3 and 4 can be regarded as antenna elements or TXRU with the same or similar polarization directions. Then 1 and 2 generate digital beams corresponding to the first polarization direction, and 3 and 4 generate digital beams corresponding to the second polarization direction. Based on this understanding, the orthogonal basis corresponding to the above precoding matrix set {0,2,8,10} and the precoding matrix set {5,7,13,15} is the case where the digital beams corresponding to the two port groups with the same polarization direction are orthogonal, and the orthogonal basis corresponding to the above precoding matrix set {1,3,9,11} and the precoding matrix set {4,6,12,14} is the case where the digital beams corresponding to the two port groups with the same polarization direction are the same. In fact, Figure 2The dual-polarized array shown is assumed to be a general assumption. This point is emphasized below. First, any wireless communication system needs to have the ability to send / receive electromagnetic waves in two polarization directions, while any antenna or TXRU can only send / receive one polarization direction. Therefore, especially for the transmitter, when the number of antenna elements is greater than or equal to 2, for general random channel conditions, it is easy to get better results by using dual-polarized antennas for signal transmission. When the number of antenna elements is equal to 4, for general random channel conditions, it is general to use two dual-polarized antenna pairs for signal transmission. No matter how large the spacing between the two dual-polarized antenna pairs is or how strong the correlation is, we can find a specific phase coefficient for a pair of antennas with the same or similar polarization directions for a certain frequency point and a certain channel environment. The two polarized antenna pairs can also be regarded as being combined by a certain phase coefficient. Therefore, dual-polarized arrays are ubiquitous and are not the antenna form corresponding to a specific UE. Secondly, for any dual-polarized antenna pair, Figure 2 The port order shown is general. In implementation, each terminal manufacturer can default to Figure 2 The ports are ordered as shown to send reference signals.

[0149] Secondly, in conjunction with the relevant content of the dual-polarized antenna pair, the relevant explanation of the precoding matrix in this application is as follows:

[0150] Specifically, an N-port precoding matrix with a rank of r can be used to precode R data transmission layers and obtain uplink transmission signals on N antenna ports. In other words, each column of the precoding matrix corresponds to a data stream, and each row of the precoding matrix corresponds to an antenna port. The rank of the precoding matrix, that is, the number of columns, is the number of data streams for spatial division multiplexing. The number of ports of the precoding matrix, that is, the number of rows, is the number of antenna ports for sending signals. The antenna port is an abstract concept, which can correspond to a specific physical antenna or a beam that has been beamformed (usually also called a virtual antenna).

[0151] Based on this, any precoding matrix P can be written as follows:

[0152]

[0153] Where n is the scalar part of the precoding matrix, and A is the non-scalar part of the precoding matrix, where each element α is nr It can only take 0 or complex numbers modulo 1, n = 1, 2, ..., N, r = 1, 2, ..., R.

[0154] Generally speaking, when N=4, the four ports of uplink transmission can be regarded as including two port groups, each port group corresponds to a dual-polarized antenna pair, or a pair of two beams with the same beam direction but different polarization directions. For example, assuming that the four antenna ports are numbered 1, 2, 3, and 4, then in the LTE uplink codebook design, ports {1, 3} correspond to the same port group, and ports {2, 4} correspond to the same port group. Generally speaking, ports {1, 2} have the same polarization direction and can be beamformed by generating a transmit phase difference; ports {3, 4} have the same polarization direction and can be beamformed by generating a transmit phase difference. At this time, in the non-scalar part of a 4-port precoding matrix, each column actually indicates the beam information corresponding to the two polarization directions in the precoding corresponding to a certain transmission layer, that is, it indicates the beam space of these four ports. If there is a column where the transmit phase difference corresponding to port {1,2} is the same as the transmit phase difference corresponding to port {3,4}, it is called a co-directional beam space; if there is a column where the transmit phase difference corresponding to port {1,2} is opposite to the transmit phase difference corresponding to port {3,4}, it is called a reverse beam space. If there are two columns where the transmit phase difference corresponding to port {1,2} is the same and the transmit phase difference corresponding to port {3,4} is also the same, the beam spaces of the two columns are said to be exactly the same. If there are two columns where the transmit phase difference corresponding to port {1,2} is opposite and the transmit phase difference corresponding to port {3,4} is also opposite, the beam spaces of the two columns are said to be completely opposite. Based on this, the transmit phase difference between port 1 and port 3 is actually the phase difference between the beams in the two polarization directions, which is generally called the cross-polarization phase.

[0155] For example, for the precoding matrix 0 in Table 1, the beam spaces corresponding to the two dual-polarized antenna pairs are opposite, the beam space corresponding to the port group composed of {port 1, port 2} is [1, 1], the beam space corresponding to the port group composed of {port 3, port 4} is [1, -1], and the cross-polarization phases of the two port groups are [1, 1]. For another example, for the precoding matrix 6 in Table 1, the beam spaces corresponding to the two dual-polarized antenna pairs are the same, the beam spaces corresponding to the port group composed of {port 1, port 2} and the port group composed of {port 3, port 4} are both [1, j], and the corresponding cross-polarization phases are [1, -1].

[0156] In addition, the 2-norm ||a||2 of a vector a is defined as follows (a can be a row vector or a column vector. The following example uses a column vector as an example. The calculation method of the row vector is exactly the same. N is the number of elements contained in a):

[0157]

[0158] Secondly, there are 4 transmission ports for the terminal (i.e. Figure 2 The analysis of the universal application scenarios of the dual-polarized antenna pair corresponding to the 4 antenna ports is as follows:

[0159] Scenario 1: All four transmission ports can perform coherent transmission.

[0160] Scenario 2: The four transmission ports can be divided into two groups. Coherent transmission is possible within the groups, but coherent transmission is not possible between groups.

[0161] Scenario 3: Only incoherent transmission can be performed between the four transmission ports, that is, none of the four transmission ports can perform coherent transmission.

[0162] Based on the above analysis and assumptions, the criteria for uplink codebook design in this application are summarized as follows:

[0163] First, in order to ensure that when rank = 1, the terminal multi-antenna precoding is not affected by waveform switching, in this application, the precoding matrix of rank = 1 under the CP-OFDM waveform uses the precoding matrix under the DFT-S-OFDM waveform, as shown in Table 5.

[0164] Secondly, in order to reduce the complexity of terminal implementation, the non-scalar parts in all precoding matrices with rank>1 are obtained by column merging the non-scalar parts of the precoding matrix with rank=1.

[0165] Again, the characteristics of the precoding matrix corresponding to each scenario are as follows: the characteristic of the precoding matrix corresponding to scenario one is that any column in any precoding matrix of rank > 1 contains at most 4 non-zero elements; the characteristic of the precoding matrix corresponding to scenario two is that any vector in any precoding matrix of rank > 1 contains at most 2 non-zero elements; the characteristic of the precoding matrix corresponding to scenario three is that any vector in any precoding matrix of rank > 1 contains at most 1 non-zero elements.

[0166] Based on the current port grouping and assumptions, the present application designs precoding matrices for coherent, partially coherent and incoherent scenarios respectively. The designed codebook is universal, and the number of precoding matrices can be minimized, thereby optimizing the system transmission performance under the restriction that "the number of indication bits when TPMI and TRI are mixed in the control signaling must be less than 6 bits".

[0167] In addition, for the problem of antenna gain imbalance (AGI) caused by obstruction of the four transmission ports (for example, some transmission ports may be blocked by the user's hands), the present application also provides a corresponding solution, that is, a precoding matrix with a function of indicating shutting down part of the terminal's RF chain is added to the precoding matrix with rank > 1. These precoding matrices are used to set the transmission power of the blocked transmission port to 0.

[0168] Based on the design ideas of the uplink codebook in the above three scenarios, this application provides a communication method, such as Figure 7 As shown, it mainly includes the following steps:

[0169] Step 101: The base station determines indication information, and sends the indication information to the terminal. The indication information includes a first bit field, and the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix.

[0170] The precoding matrix is ​​used to precode the transmission data streams on r transmission layers to obtain signals sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r.

[0171] In which, when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1.

[0172] For a detailed description of the precoding matrix, please refer to the above explanation of the precoding matrix.

[0173] Step 102: The terminal receives the indication information sent by the base station, and determines the precoding matrix for precoding the transmission data streams on all transmission layers.

[0174] Step 103: The terminal precodes the transmission data streams on all transmission layers according to the precoding matrix to obtain transmission signals on N transmission ports, and sends the transmission signals to the base station.

[0175] In the present application, when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1, that is, the precoding matrices with rank>1 in the uplink codebook can be regarded as the splicing of precoding matrices with rank=1, thereby reducing the implementation complexity of the terminal and ensuring an uplink codebook with a smaller downlink signaling indication overhead and better performance. Compared with the uplink codebook using DFT-s-OFDM waveform used in LTE-A in the prior art, in the codebook design of rank=2 and rank=3, the precoding matrix is ​​generated by extracting the columns of MUB, which is conducive to maximizing the minimum spacing between precoding matrices and improving performance.

[0176] Optionally, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, and -j.

[0177] Optionally, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0178] Optionally, the four transmission ports are divided into a first port group and a second port group, wherein the two transmission ports included in the first port group and the second port group correspond to a dual-polarized antenna pair, or correspond to two beams with the same beam direction but perpendicular polarization directions. Figure 2 In the assumption of the dual-polarized antenna pair shown, the first port group includes two transmission ports, namely port 1 and port 3, and the second port group includes two transmission ports, namely port 2 and port 4. Port 1 and port 3 correspond to one dual-polarized antenna pair, and port 2 and port 4 correspond to another dual-polarized antenna pair. Or port 1 and port 3 correspond to two beams with the same beam direction but perpendicular polarization directions, and port 2 and port 4 correspond to two beams with the same beam direction but perpendicular polarization directions.

[0179] The present application takes into account the scenario of universal uplink transmission, and can maximize the minimum spacing between precoding matrices and reduce DCI signaling indication overhead.

[0180] Optionally, in the first implementation scenario of the above embodiment, the terminal supports a fully coherent transmission state of four transmission ports, that is, coherent transmission can be performed within the first port group, the second port group, and between the first port group and the second port group. Accordingly, the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario one.

[0181] When the first precoding matrix set in step 101 is an uplink codebook corresponding to scenario 1, correspondingly, the characteristics of the precoding matrix with a transmission rank of 1 and the precoding matrix with a transmission rank greater than 1 included in the first precoding matrix set in step 101 are as follows:

[0182] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset contain 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices contain 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element contained in each of the 4 precoding matrices is located are different.

[0183] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, and the non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging the columns of the non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset.

[0184] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein the non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset.

[0185] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0186] Specifically, the uplink codebook solution designed for scenario 1 in this application is as follows:

[0187] When the number of transmitted data streams is 1, in order to ensure that the precoding process of the terminal's multi-antenna transmission is not affected by waveform switching when the rank is 1, the precoding matrix of rank = 1 using the CP-OFDM waveform applied in NR provided by this application is as shown in Table 5. Among them, the precoding matrix of rank = 1 shown in Table 5 is the same as the precoding matrix of rank = 1 using the DFT-s-OFDM waveform applied in NR. Unlike the LTE-A codebook, a precoding matrix with a single-port beam selection function is added to the precoding matrix of rank = 1 using the CP-OFDM waveform applied in NR, that is, the precoding matrix with precoding matrix serial number 24-27 in Table 5.

[0188] As shown in Table 5, the precoding matrix of rank=1 includes 28 precoding matrices, ie, precoding matrices with precoding matrix numbers 0-27.

[0189] Exemplarily, the precoding matrices in the first precoding matrix subset include the precoding matrices with precoding matrix numbers 0 to 15 in Table 5. The precoding matrices in the second precoding matrix subset include the precoding matrices with precoding matrix numbers 24 to 27 in Table 5.

[0190] Table 5

[0191]

[0192] For rank = 2 and fully coherent transmission, considering that the low peak-to-average ratio characteristic is no longer the main design requirement, in order to achieve the best sampling of the 4-dimensional complex space as much as possible, the minimum precoding matrix spacing needs to be maximized. Therefore, this scheme adopts the column selection method based on the MUB basis to obtain a precoding matrix of rank = 2.

[0193] When the number of transmission data streams is 2, all precoding matrices with a transmission rank of 2 include a third precoding matrix subset, and the non-scalar part of each precoding matrix in the third precoding matrix subset includes two columns, and the two columns include columns of two mutually orthogonal precoding matrices selected from the first precoding matrix subset.

[0194] That is to say, when determining the non-scalar part of any precoding matrix with a transmission rank of 2, two orthogonal precoding matrices can be selected from the precoding matrices with precoding matrix numbers 0-15 in Table 5, and the columns of the two orthogonal precoding matrices are merged to obtain the non-scalar part of a precoding matrix with a transmission rank of 2. The column merging here refers to placing the single columns of two precoding matrices with a rank of 1 side by side to form two columns. Since the precoding matrix number and the transmission order number are mixed coded, there is no restriction on the order of the two single columns.

[0195] The precoding matrices with precoding matrix numbers 0-15 in Table 5 are exactly the same as the precoding matrices with precoding matrix numbers 0-15 in Table 1. Based on the explanation of the precoding matrices with precoding matrix numbers 0-15 shown in Table 1 in this application, it can be seen that there are 4 groups of orthogonal bases for the precoding matrices with precoding matrix numbers 0-15, each group of orthogonal bases includes 4 precoding matrices, and the 4 precoding matrices are mutually orthogonal. For the convenience of description, the precoding matrices included in the 4 groups of orthogonal bases are represented by a set of precoding matrix numbers, as follows:

[0196] Orthogonal basis 1: [0,2,8,10]

[0197] Orthogonal basis 2: [1,3,9,11]

[0198] Orthogonal basis 3: [4,6,12,14]

[0199] Orthogonal basis 4: [5,7,13,15]

[0200] Reference to this application Figure 2 Based on the understanding of the present invention, the present application provides three methods for selecting two orthogonal precoding matrices from the above four orthogonal bases to generate a precoding matrix with rank = 2.

[0201] Method 1: Column merging of precoding matrices with the same beam space but different cross-polarization phases in four groups of orthogonal bases is performed to obtain a precoding matrix of rank = 2. The columns of the non-scalar parts of the eight precoding matrices obtained are: [0, 2]; [8, 10]; [1, 3]; [9, 11]; [4, 6]; [12, 14]; [5, 7]; [13, 15].

[0202] It should be noted that when the precoding matrix indicated by TPMI changes, the total average power of the corresponding transmission port remains unchanged unless the port is closed (the corresponding element is 0). This feature should be applied to the codebook design of rank>1. Therefore, in order to ensure that when the precoding matrix indicated by TPMI changes, including when the rank changes, the total average power of the corresponding transmission port remains unchanged, the normalization factor of each precoding matrix of rank=2 should be The normalization factor is the scalar part of the precoding matrix.

[0203] Therefore, according to the columns and normalization factors of the precoding matrix in Table 5 corresponding to the precoding matrix numbers in [0,2]; [8,10]; [1,3]; [9,11]; [4,6]; [12,14]; [5,7]; [13,15] The 8 precoding matrices that can be obtained are as follows:

[0204]

[0205] Among them, these 8 precoding matrices are called the first type of precoding matrices in the precoding matrix of rank=2, that is, the beam spaces of the first column and the second column of the first type of precoding matrix are completely the same, but the cross-polarization phases are different.

[0206] Method 2: Column merging of precoding matrices with opposite beam spaces but the same cross-polarization phase in 4 groups of orthogonal bases is performed to obtain a precoding matrix of rank = 2. The columns of the non-scalar part of the 8 precoding matrices obtained in this way are: [0,8]; [2,10]; [1,9]; [3,11]; [4,12]; [6,14]; [5,13]; [7,15]. According to the columns of the precoding matrices in Table 5 corresponding to the precoding matrix numbers in [0,8]; [2,10]; [1,9]; [3,11]; [4,12]; [6,14]; [5,13]; [7,15], and the normalization factors determined The 8 precoding matrices that can be obtained are as follows:

[0207]

[0208] Among them, these 8 precoding matrices are called second-type precoding matrices in the precoding matrix of rank=2, that is, the beam spaces of the first column and the second column of the second-type precoding matrix are opposite, but the cross-polarization phases are the same.

[0209] Method 3: Column merging is performed on the precoding matrices with opposite beam spaces and different cross-polarization phases in the four orthogonal bases to obtain a precoding matrix of rank = 2. The columns of the non-scalar parts of the eight precoding matrices obtained are: [0, 10]; [2, 8]; [1, 11]; [3, 9]; [4, 14]; [6, 12]; [5, 15]; [7, 13].

[0210] According to the columns of the precoding matrix in Table 5 corresponding to the precoding matrix numbers in [0,10]; [2,8]; [1,11]; [3,9]; [4,14]; [6,12]; [5,15]; [7,13] and the determined normalization factors The 8 precoding matrices that can be obtained are as follows:

[0211]

[0212] Among them, these 8 precoding matrices are called the third type of precoding matrices in the precoding matrix of rank=2, that is, the beam spaces of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0213] As an optional embodiment, the third precoding matrix subset includes the above-mentioned 8 first-type precoding matrices, the above-mentioned 8 second-type precoding matrices and the above-mentioned 8 third-type precoding matrices at the same time, then the above-mentioned third precoding matrix subset includes 24 precoding matrices, which can maximize the minimum value of the projection 2-norm distance. Here, the projection 2-norm distance is a kind of Grassmannian space distance. There is a document [1] that proves that maximizing the minimum projection 2-norm distance between precoding matrices can achieve the optimal MSE decoding performance. ([1] DJ Love and RW Heath, "Limited feedback unitary precoding for spatial multiplexing systems," in IEEE Transactions on Information Theory, vol. 51, no. 8, pp. 2967-2976, Aug. 2005. doi: 10.1109 / TIT.2005.850152)

[0214] When the number of transmission data streams is 3, for the case of rank = 3 and full coherence, a similar criterion as rank = 2 is adopted to perform 4-choose-3 exhaustive enumeration of 4 sets of orthogonal bases, and 16 precoding matrices can be generated. The columns included in the non-scalar part of these 16 precoding matrices can be expressed as:

[0215] [0,2,8]; [8,10,2]; [1,3,9]; [9,11,3]; [4,6,12]; [12,14,6]; [5,7,13]; [13,15,7]; [0,8,10]; [2,10,0]; [1,9,11]; [3,11,1]; [4,12,14]; [6,14,4]; [5,13,15]; [7,15,5].

[0216] In order to ensure that the total average power of the corresponding transmission port remains unchanged when the precoding matrix indicated by TPMI changes, including when the rank changes, the normalization factor of each precoding matrix with rank = 3 should be The normalization factor is the scalar part of the precoding matrix.

[0217] According to the columns of the precoding matrix in Table 5 corresponding to these precoding matrix numbers and the normalization factors determined The 16 precoding matrices that can be obtained are as follows:

[0218]

[0219] As an optional embodiment, the fourth precoding matrix subset may include these 16 precoding matrices.

[0220] When the number of transmission data streams is 4, the rank is 4. Since the precoding matrix with 4 rows and 4 columns is a full-rank square matrix, the projected 2-norm distance between any two orthogonal bases is 0. Therefore, for the case of rank 4, consistent with the LTE-A codebook, only one precoding matrix is ​​designed, and the non-scalar part of this precoding matrix includes four columns. These four columns include the columns of all precoding matrices included in the second precoding matrix subset and can be expressed as: [24, 25, 26, 27].

[0221] In order to ensure that the total average power of the corresponding transmission port remains unchanged when the precoding matrix indicated by TPMI changes, including when the rank changes, the normalization factor of the precoding matrix with rank = 4 should be

[0222] According to the columns of the precoding matrix in Table 5 corresponding to these precoding matrix numbers and the normalization factors determined The precoding matrix of rank = 4 can be obtained as:

[0223]

[0224] In addition, when the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario 1, assuming that antenna shielding occurs at the four antenna ports, that is, AGI occurs, then AGI is likely to occur on a pair of dual-polarized antennas (i.e., on one port group). Based on this assumption, transmission of rank 2 can still be performed on another pair of dual-polarized antennas. Based on this, the present application also adds 2 precoding matrices to all precoding matrices with a transmission rank of 2 to indicate that the transmission ports included in the same port group are closed.

[0225] Optionally, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset includes a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the first precoding matrix contains rows of non-zero elements, and the corresponding transmission ports are the transmission ports included in the first port group; the second precoding matrix contains rows of non-zero elements, and the corresponding transmission ports are the transmission ports included in the second port group. Two precoding matrices are added to the precoding matrix of rank = 2 to close the RF link of the blocked transmission port.

[0226] Specifically, consider Figure 2 For the corresponding dual-polarized antenna pair assumption, the rank = 2 precoding matrix can be supplemented with two precoding matrices for port selection. The columns of the non-scalar parts of these two precoding matrices can be expressed as: [24, 26], [25, 27]. According to the columns of the precoding matrices in Table 5 corresponding to these precoding matrix numbers and the determined normalization factors The two precoding matrices can be obtained as:

[0227]

[0228] As in the case of rank = 4, since rank 2 transmission is performed on the port group that is not closed, the submatrix consisting of rows containing non-zero elements in the first precoding matrix and the second precoding matrix is ​​a full rank square matrix. Since the projected 2-norm distance between any two orthogonal bases in the orthogonal bases of all full rank square matrices is 0, only one codeword needs to be designed for each port group that is not closed.

[0229] It can be seen that based on such a design, for the case of full coherence, if the TRI and TPMI of all precoding matrices supporting rank = 1 to rank = 4 are indicated by the first bit field, then:

[0230] The number of all precoding matrices of rank=1 is 28 precoding matrices, ie, the precoding matrices with precoding matrix numbers 0-27 shown in Table 5.

[0231] The number of all precoding matrices of rank=2 is 26 precoding matrices, and the 26 precoding matrices include 24 precoding matrices in the third precoding matrix subset and 2 precoding matrices in the eighth precoding matrix subset.

[0232] The number of all precoding matrices of rank=3 is 16 precoding matrices, ie, the 16 precoding matrices in the fourth precoding matrix subset.

[0233] The number of precoding matrices of rank=4 is 1 precoding matrix.

[0234] Therefore, there are a total of 28+26+16+1=71 precoding matrices. If TPMI and transmit rank indication (TRI) are mixed encoded, that is, when the indication information in step 101 includes a first bit field, and the first bit field indicates a precoding matrix in a first precoding matrix set and its corresponding transmission rank, the first bit field requires 7 bits to indicate.

[0235] The indication information in step 101 is indicated to the terminal through DCI. Considering that the DCI indication bits should be as small as possible to ensure high-reliability decoding of the downlink control channel, it is necessary to consider removing 8 precoding matrices from 71 precoding matrices to form an uplink codebook of 63 precoding matrices. In this way, only 6 bits are needed to indicate TPMI and TRI.

[0236] The implementation method of removing 8 precoding matrices from 71 precoding matrices provided in this application includes the following implementation options:

[0237] Implementation option 1: the third precoding matrix subset with reserved rank=2 includes any two of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix.

[0238] For example, 8 first-type precoding matrices in the third precoding matrix subset of rank=2 are removed, that is, the third precoding matrix subset retains 8 second-type precoding matrices and 8 third-type precoding matrices.

[0239] For example, eight second-type precoding matrices in the third precoding matrix subset of rank=2 are removed, that is, the third precoding matrix subset retains eight first-type precoding matrices and eight third-type precoding matrices.

[0240] For example, 8 third-type precoding matrices in the third precoding matrix subset of rank=2 are removed, that is, the third precoding matrix subset retains 8 first-type precoding matrices and 8 second-type precoding matrices.

[0241] Considering that when the beam spaces are opposite, the necessity of selecting opposite cross-polarization phases is relatively low, the third precoding matrix subset may retain 8 first-type precoding matrices and 8 second-type precoding matrices.

[0242] Implementation option 2: retaining 8 first-type precoding matrices, 4 second-type precoding matrices, and 4 third-type precoding matrices in the third precoding matrix subset of rank=2.

[0243] For rank = 2, the second type of precoding matrix and the third type of precoding matrix both include precoding matrices with opposite beam spaces. If 4 second type of precoding matrices and 4 third type of precoding matrices are removed, uniform sampling can be ensured for situations where the cross-polarization phases are the same or different. It should be noted that it is necessary to ensure that the remaining precoding matrices are included in 4 groups of orthogonal bases, and when deleting a precoding matrix, two orthogonal precoding matrices in the same group of orthogonal bases need to be deleted at the same time.

[0244] For example, in the precoding matrix of rank = 2, 4 precoding matrices [1,9]; [3,11]; [4,12]; [6,14] of the 8 second-type precoding matrices [0,8]; [2,10]; [1,9]; [3,11]; [4,12]; [6,14] are removed, and 4 precoding matrices [0,10]; [2,8]; [5,15]; [7,13] of the 8 third-type precoding matrices [0,10]; [2,8]; [1,11]; [3,9]; [4,14]; [6,12]; [5,15]; [7,13] are removed.

[0245] Implementation option three: remove 4 precoding matrices from the third precoding matrix subset of rank = 2, the columns of these 4 precoding matrices include columns of precoding matrices selected from precoding matrices with orthogonal basis 1 and orthogonal basis 4 of rank 1; remove 4 precoding matrices from the fourth precoding matrix subset of rank = 3, the columns of these 4 precoding matrices include columns of precoding matrices selected from precoding matrices with orthogonal basis 1 and orthogonal basis 4 of rank 1.

[0246] This implementation option optimizes the number of precoding matrices for the case where the beam spaces corresponding to the two polarization directions are highly correlated. When two transmission port groups are highly correlated (for example, the spacing between the dual-polarized antenna pairs corresponding to the two transmission port groups is 0.5 wavelengths), and when the rank is > 1, the probability of orthogonal basis 1 and orthogonal basis 4 appearing is lower than that of orthogonal basis 2 and orthogonal basis 3. Therefore, for the cases of rank = 2 and rank = 3, four precoding matrices corresponding to the precoding matrices of orthogonal basis 1 and orthogonal basis 4 of rank 1 are removed. For example, when rank = 2, the following four precoding matrices [5,13]; [7,15]; [0,8]; [2,10] are removed from the third precoding matrix subset. When rank = 3, the following four precoding matrices are removed from the fourth precoding matrix subset: [0,8,10]; [2,10,0]; [5,13,15]; [7,15,5].

[0247] Table 6

[0248]

[0249] Table 7

[0250]

[0251] Table 8

[0252]

[0253] Implementation option 4: Remove 8 precoding matrices from the fourth precoding matrix subset of rank = 3, where the columns of the 8 precoding matrices include columns of precoding matrices selected from precoding matrices of orthogonal basis 1, orthogonal basis 2, orthogonal basis 3, and orthogonal basis 4 of rank 1. For example, when rank = 3, remove the following 8 precoding matrices from the fourth precoding matrix subset: [0, 8, 10]; [2, 10, 0]; [1, 9, 11]; [3, 11, 1]; [4, 12, 14]; [6, 14, 4]; [5, 13, 15]; [7, 15, 5].

[0254] With respect to the optimization scheme for the number of precoding matrices implemented in option three, the present application provides an optimized first precoding matrix set.

[0255] Among them, the 28 precoding matrices with rank equal to 1 are shown in Table 5.

[0256] See Table 6 for the 22 precoding matrices with rank equal to 2, including 20 precoding matrices of the third precoding matrix subset (precoding matrix numbers are 0-19 in Table 6) and 2 precoding matrices of the eighth precoding matrix (precoding matrix numbers are 20-21 in Table 6).

[0257] The 12 precoding matrices with a rank equal to 3, see Table 7, include 12 precoding matrices of the fourth precoding matrix subset (the precoding matrix numbers in Table 7 are 0-11).

[0258] 1 precoding matrix with rank equal to 4, see Table 8.

[0259] Based on such a design, the uplink codebook corresponding to scenario 1 includes 28+22+12+1=63 precoding matrices in total. If TPMI and TRI are mixed coded, only 6 bits are required for indication.

[0260] Optionally, on the basis of dividing the four transmission ports into the first port group and the second port group, in the second implementation scenario of the above embodiment, the terminal supports semi-coherent transmission state of the four transmission ports, that is, coherent transmission can be performed within the first port group and the second port group, and coherent transmission cannot be performed between the first port group and the second port group. Accordingly, the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario two.

[0261] When the first precoding matrix set in step 101 is an uplink codebook corresponding to scenario 1, correspondingly, the characteristics of the precoding matrix with a transmission rank of 1 and the precoding matrix with a transmission rank greater than 1 included in the first precoding matrix set in step 101 are as follows:

[0262] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset contain 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices contain 1 non-zero element and 3 zero elements, and the rows in which the 1 non-zero element contained in each of the 4 precoding matrices are located are different.

[0263] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein the non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging the columns of the non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset.

[0264] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset.

[0265] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0266] Specifically, the uplink codebook solution designed in this application for scenario 2 is as follows:

[0267] Unlike the precoding matrices of LTE-A with ranks of 2 and 3, for the case of partial coherence, the UE can know which two transmission ports can perform coherent transmission, so there is no need to exhaust all possible port combinations as in LTE. When ports 1 and 3 in the first port group can perform coherent transmission, and / or ports 2 and 4 in the second port group can perform coherent transmission, the present application provides a solution for the uplink codebook designed for scenario 2.

[0268] When the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario 2, for the case of rank=1, the precoding matrices with precoding matrix numbers 16-27 in table 5 are reused, and a total of 12 precoding matrices are used as all precoding matrices with a transmission rank of 1.

[0269] According to the number of non-zero elements contained in the columns of the precoding matrix, all precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the fifth precoding matrix subset includes the precoding matrices with precoding matrix numbers 16-23 in Table 5, and the number of non-zero elements contained in the columns of each precoding matrix is ​​2, and the second precoding matrix subset includes the precoding matrices with precoding matrix numbers 24-27 in Table 5, and the number of non-zero elements contained in the columns of each precoding matrix is ​​1. Referring to Table 5, among the four precoding matrices with precoding matrix numbers 24-27, the rows where the one non-zero element contained in each precoding matrix is ​​located are different.

[0270] When the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario 2, for the case of rank = 2, the inherited Figure 2 Based on the assumption of two pairs of dual-polarized antenna pairs in , the QPSK phases of each dual-polarized antenna pair can be enumerated, that is, the columns of two precoding matrices arbitrarily selected from the fifth precoding matrix subset. The columns of the non-scalar part of the 16 precoding matrices obtained are: [16,20]; [16,21]; [16,22]; [16,23]; [17,20]; [17,21]; [17,22]; [17,23]; [18,20]; [18,21]; [18,22]; [18,23]; [19,20]; [19,21]; [19,22]; [19,23].

[0271] In order to ensure that the total average power of the corresponding transmission port remains unchanged when the precoding matrix indicated by TPMI changes, including when the rank changes, the normalization factor of the precoding matrix with rank = 2 should be

[0272] According to the columns of the precoding matrix in Table 5 corresponding to these precoding matrix numbers and the normalization factors determined The precoding matrix of rank = 2 can be obtained as:

[0273]

[0274] The sixth precoding matrix subset with rank=2 includes these 16 precoding matrices.

[0275] When the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario 2, for the case of rank = 3, since two transmission layers are transmitted on one of the port groups, the columns corresponding to the two transmission layers corresponding to this port group and the submatrix consisting of the rows containing non-zero elements in these two columns are a full rank square matrix. Since the projected 2-norm distance between any two orthogonal bases in the orthogonal bases of all full rank square matrices is 0, only one precoding matrix needs to be defined for the port group that transmits two transmission layers. Therefore, the precoding matrix of rank = 3, one column of which is a column of the precoding matrix selected from the above-mentioned fifth precoding matrix subset, and the remaining two columns include columns of two precoding matrices selected from the second precoding matrix subset. The columns included in the non-scalar part of the 8 precoding matrices obtained are: [16, 25, 27]; [17, 25, 27]; [18, 25, 27]; [19, 25, 27]; [20, 24, 26]; [21, 24, 26]; [22, 24, 26]; [23, 24, 26].

[0276] In order to ensure that the total average power of the corresponding transmission port remains unchanged when the precoding matrix indicated by TPMI changes, including when the rank changes, the normalization factor of the precoding matrix with rank = 3 should be

[0277] According to the columns of the precoding matrix in Table 5 corresponding to these precoding matrix numbers and the normalization factors determined The 8 precoding matrices with rank = 3 can be obtained as follows:

[0278]

[0279] The seventh precoding matrix subset with rank=3 includes these 8 precoding matrices.

[0280] In addition, when the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario 2, assuming that antenna shielding occurs at the four antenna ports, that is, AGI will also occur, then AGI is likely to occur on a pair of dual-polarized antennas (i.e., on one port group). Based on this assumption, on another pair of dual-polarized antennas, transmission of rank 2 can still be performed. Based on this, the present application also adds 2 precoding matrices to all precoding matrices with a transmission rank of 2 to indicate that the transmission ports included in the same port group are closed.

[0281] consider Figure 2For the corresponding dual-polarized antenna pair assumption, the rank = 2 precoding matrix can be supplemented with two precoding matrices for port selection. The columns of the non-scalar parts of these two precoding matrices can be expressed as: [24, 26], [25, 27]. According to the columns of the precoding matrices in Table 5 corresponding to these precoding matrix numbers and the determined normalization factors The two precoding matrices can be obtained as:

[0282]

[0283] When the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario 2, it is obvious that the precoding matrix of rank = 4 should also be exactly the same as scenario 1, so there is a precoding matrix, and the columns contained in its non-scalar part are expressed as [24, 25, 26, 27]. Substitute the columns of the precoding matrix in Table 5 corresponding to these precoding matrix numbers and the determined normalization factor The precoding matrix of rank = 4 is:

[0284]

[0285] It can be seen that based on such a design, for scenario 2 where only the transmission ports in the port group can transmit coherently, if the TRI and TPMI supporting all precoding matrices from rank = 1 to rank = 4 are indicated by the first bit field, then:

[0286] The number of all precoding matrices of rank=1 is 12 precoding matrices, ie, the precoding matrices with precoding matrix numbers 16-27 shown in Table 5.

[0287] The number of all precoding matrices of rank=2 is 18 precoding matrices, and the 18 precoding matrices include 16 precoding matrices in the sixth precoding matrix subset and 2 precoding matrices in the eighth precoding matrix subset.

[0288] The number of all precoding matrices of rank=3 is 8 precoding matrices, ie, the 8 precoding matrices in the seventh precoding matrix subset.

[0289] The number of precoding matrices of rank=4 is 1 precoding matrix.

[0290] Therefore, there are a total of 12+18+8+1=39 precoding matrices. If TPMI and TRI are mixed coded, that is, when the indication information in step 101 includes a first bit field, and the first bit field indicates a precoding matrix in a first precoding matrix set and its corresponding transmission rank, the first bit field requires 6 bits to indicate.

[0291] The indication information in step 101 is indicated to the terminal through DCI. Considering that the DCI indication bits should be as small as possible to ensure high-reliability decoding of the downlink control channel, it is necessary to consider removing 8 precoding matrices from 39 precoding matrices to form an uplink codebook of 31 precoding matrices. In this way, only 5 bits are needed to indicate TPMI and TRI.

[0292] The implementation method of removing 8 precoding matrices from 39 precoding matrices provided in this application includes the following implementation options:

[0293] Implementation option 1: remove 8 precoding matrices from the 16 precoding matrices in the sixth precoding matrix subset of rank=2.

[0294] Considering that in the scenario of rank = 2, exhaustively enumerating all phase combinations brings a large overhead, so we can remove 8 precoding matrices from the 16 precoding matrices.

[0295] Optionally, to maintain consistency with the uplink codebook of LTE-A, for each precoding matrix retained from the 16 precoding matrices of rank=2, the phases of the two dual-polarization pairs come from different orthogonal phase combinations.

[0296] For example, the columns of the non-scalar part of the remaining 8 precoding matrices can be expressed as: [16, 22]; [16, 23]; [17, 22]; [17, 23]; [18, 20]; [18, 21]; [19, 20]; [19, 21]. The remaining 8 precoding matrices are:

[0297]

[0298] Among them, For example, the transmission phase difference between port 1 and port 3 is different from the transmission phase difference between port 2 and port 4. Therefore, the phase of the dual-polarization pair corresponding to port 1 and port 3 and the phase of the dual-polarization pair corresponding to port 2 and port 4 come from different orthogonal phase combinations.

[0299] Correspondingly, among the 8 precoding matrices removed from the 16 precoding matrices of rank=2, the phases of the two dual-polarization pairs corresponding to each precoding matrix come from the same orthogonal phase combination.

[0300] For example, the columns contained in the non-scalar parts of the 8 removed precoding matrices can be expressed as: [16, 20]; [16, 21]; [17, 20]; [17, 21]; [18, 22]; [18, 23]; [19, 22]; [19, 23], and the 8 removed precoding matrices are:

[0301]

[0302] Implementation option 2: Remove 4 precoding matrices from the 16 precoding matrices in the sixth precoding matrix subset of rank=2. Remove 4 precoding matrices from the 8 precoding matrices in the seventh precoding matrix subset of rank=3.

[0303] For example, the four precoding matrices removed from the sixth precoding matrix of rank = 2 are: the phases of the two dual-polarization pairs come from the same orthogonal phase combination, and the four precoding matrices whose transmit phase difference is not a BPSK phase difference can be expressed as: [18, 22]; [18, 23]; [19, 22]; [19, 23], and the four precoding matrices removed are as follows:

[0304]

[0305] The 4 precoding matrices removed from the seventh precoding matrix of rank = 3 are: corresponding to the transmission layers of all two ports in a transmission port group, that is, corresponding to the columns of the fifth precoding matrix subset, the 4 precoding matrices whose transmission phase difference is not the BPSK phase difference can be expressed as: [18, 25, 27]; [19, 25, 27]; [22, 24, 26]; [23, 24, 26]. The 4 precoding matrices removed are as follows:

[0306]

[0307] In view of the optimization scheme for the number of precoding matrices in implementation option 1, the present application provides a first precoding matrix set optimized in scenario 2, including:

[0308] When the number of transmission data streams is 1, rank=1, and 12 precoding matrices of rank=1 refer to the precoding matrices with precoding matrix numbers 16-27 in Table 5.

[0309] When the number of transmitted data streams is 2, rank = 2, and the 10 precoding matrices of rank = 2 are shown in Table 9, including 8 precoding matrices of the sixth precoding matrix subset (the precoding matrix numbers in Table 9 are 0-7) and 2 precoding matrices of the eighth precoding matrix (the precoding matrix numbers in Table 9 are 8-9).

[0310] When the number of transmission data streams is 3, rank=3, and the 8 precoding matrices of rank=3, see Table 10, include 8 precoding matrices of the seventh precoding matrix subset (the precoding matrix serial numbers in Table 10 are 0-7).

[0311] When the number of transmission data streams is 4, rank = 4, and rank is equal to 1 precoding matrix of 4, see Table 8.

[0312] Based on such a design, the uplink codebook corresponding to scenario 2 includes 12+10+8+1=31 precoding matrices in total. If TPMI and TRI are mixed coded, only 5 bits are required for indication.

[0313] Table 9

[0314]

[0315] Table 10

[0316]

[0317] Optionally, on the basis of the four transmission ports being divided into the first port group and the second port group, in the third implementation scenario of the above embodiment, the terminal supports incoherent transmission states of the four transmission ports, that is, no coherent transmission is possible within the first port group, the second port group, and between the first port group and the second port group. Accordingly, the first precoding matrix set in step 101 is the uplink codebook corresponding to scenario three.

[0318] When the first precoding matrix set in step 101 is an uplink codebook corresponding to scenario three, correspondingly, the characteristics of the precoding matrix with a transmission rank of 1 and the precoding matrix with a transmission rank greater than 1 included in the first precoding matrix set in step 101 are as follows:

[0319] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, the columns of each of the 4 precoding matrices contain 1 non-zero element and 3 zero elements; the row where the 1 non-zero element contained in each of the 4 precoding matrices is located is different; the transmission power of the transmission port corresponding to the row containing the zero element is 0.

[0320] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein the non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging the columns of the non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset.

[0321] All precoding matrices with a transmission rank of 3 include a tenth precoding matrix subset, wherein the non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset.

[0322] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0323] The uplink codebook scheme designed in this application for scenario 3 is as follows:

[0324] When the number of transmitted data streams is 1, rank = 1, the precoding matrices corresponding to precoding matrix numbers 24-27 in the precoding matrix reuse table 5 of rank = 1, a total of 4 precoding matrices, wherein the column of each of the 4 precoding matrices contains 1 non-zero element and 3 zero elements; the row where the 1 non-zero element contained in each of the 4 precoding matrices is located is different; the row containing the zero element, the transmission power of the corresponding transmission port is 0.

[0325] When the number of transmission data streams is 2, the rank = 2, and the non-scalar part of each precoding matrix of rank = 2 includes two columns, and the two columns include all combinations of columns of two precoding matrices selected arbitrarily from the four precoding matrices of rank = 1. The obtained 6 precoding matrices can be expressed as: [24,26]; [25,27][24,25]; [26,27][24,27]; [25,26]. The obtained 6 precoding matrices are shown in the precoding matrices corresponding to the precoding matrix numbers 0-5 in Table 11.

[0326] When the number of transmission data streams is 3, the rank = 3, and the non-scalar part of each precoding matrix of rank = 3 includes three columns, and the three columns include all combinations of columns of three precoding matrices selected arbitrarily from the four precoding matrices of rank = 1. The obtained four precoding matrices can be expressed as [24, 25, 26]; [24, 25, 27]; [24, 26, 27]; [25, 26, 27]. The obtained four precoding matrices are shown in the precoding matrices corresponding to the precoding matrix numbers 0-3 in Table 12.

[0327] When the number of transmission data streams is 4, rank=4, and the precoding matrix of rank=4 is shown in Table 8.

[0328] Based on such a design, the uplink codebook corresponding to scenario three is satisfied, with a total of 4+6+4+1=15 precoding matrices. If TPMI and TRI are mixedly coded, only 4 bits are required for indication.

[0329] In addition, in an optional embodiment, the scalar part of the precoding matrix in all tables of all the above embodiments can be 1. In this case, the base station obtains the terminal power control margin by receiving the power headroom (PHR) report.

[0330] This application designs a streamlined uplink codebook for three different scenarios related to coherent transmission, which can ensure a small downlink signaling indication overhead and better performance. The precoding matrix with rank>1 in the uplink codebook can be regarded as a concatenation of the precoding matrix with rank=1, which reduces the implementation complexity of the terminal. Compared with the prior art, no additional RRC signaling overhead is required to indicate the CBSR.

[0331] Compared with the uplink codebook using DFT-S-OFDM waveform used in LTE-A in the prior art, this application considers three different scenarios in the design of codebooks with rank = 2 and rank = 3, and generates a precoding matrix by column extraction of MUB, which is conducive to maximizing the minimum spacing between precoding matrices and improving performance.

[0332] Compared with the uplink codebook using DFT-S-OFDM waveform used in NR in the prior art, the precoding matrix design of this application is more concise and compact, which can minimize the indication overhead of DCI and does not require any RRC signaling overhead to indicate CBSR.

[0333] This application considers the scenario of universal uplink transmission, which can maximize the minimum spacing between precoding matrices and reduce the DCI signaling indication overhead. In addition, for all scenarios, it is designed that when there is antenna blocking, two precoding matrices are added to the precoding matrix of rank = 2 to close the RF link of the blocked transmission port.

[0334] Table 11

[0335]

[0336] Table 12

[0337]

[0338] Based on the same inventive concept, Figure 3 As shown, an apparatus 20 provided in an embodiment of the present application includes at least one processor 21, a communication bus 22, a memory 23 and at least one communication interface 24.

[0339] For example, Figure 2 The terminal 200 in the embodiment may also be Figure 3 The device 20 shown. The device 20 can implement the terminal-related steps in the communication method in the embodiment of the present application through the processor 21.

[0340] For example, Figure 2 The base station 100 in Figure 3 The device 20 shown can implement the steps related to the base station in the communication method in the embodiment of the present application through the processor 21.

[0341] The processor 21 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0342] The communication bus 22 may include a path to transmit information between the above components. The communication interface 24 may be any transceiver or similar device for communicating with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), WLAN, etc.

[0343] The memory 23 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by the device, but is not limited thereto. The memory may exist independently and be connected to the processor via a bus. The memory may also be integrated with the processor.

[0344] The memory 23 is used to store application code for executing the solution of the present application, and the execution is controlled by the processor 21. The processor 21 is used to execute the application code stored in the memory 23.

[0345] In a specific implementation, as an embodiment, the processor 21 may include one or more CPUs, such as Figure 3 CPU0 and CPU1 in.

[0346] In a specific implementation, as an embodiment, the device 20 may include multiple processors, such as Figure 321 and processor 28 in the embodiment of the present invention. Each of these processors can be a single-CPU processor or a multi-CPU processor. The processor here can refer to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions).

[0347] The embodiments of the present application can be used according to the above method examples. Figure 3 The device shown is divided into functional modules. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0348] In this embodiment, Figure 3 The device shown is presented in the form of dividing each functional module corresponding to each function, or the device is presented in the form of dividing each functional module in an integrated manner. The "module" here can refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions.

[0349] For example, when each functional module is divided into corresponding functional modules, Figure 4 A possible structural diagram of the device involved in the above embodiment is shown, and the device 900 may be a terminal or a base station in the above embodiment. The device 900 includes a processing unit 901 and a transceiver unit 902. The transceiver unit 902 is used for the processing unit 901 to send and receive signals. Figure 4 The method performed by the processing unit 901 in Figure 3 Specifically, the method executed by the processing unit 901 may be implemented by: Figure 3 The processor 21 (and / or processor 28) calls the application code stored in the memory 23 for execution, and the embodiment of the present application does not impose any limitation on this.

[0350] In a specific implementation, when the device 900 can be a terminal in the above embodiment, the transceiver unit 902 is used to receive indication information from the base station, the indication information includes a first bit field, the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data streams on r transmission layers to obtain signals sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1; the processing unit 901 is used to determine the precoding matrix for precoding the transmission data streams on all transmission layers according to the indication information.

[0351] In one possible design, coherent transmission can be performed between the transmission ports;

[0352] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset include 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different;

[0353] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, wherein a non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0354] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0355] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0356] In one possible design, the third precoding matrix subset includes any two or three of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix; wherein the beam space of the first column and the second column of the first type of precoding matrix are exactly the same, but the cross-polarization phases are different; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are the same; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0357] In one possible design, the transmission ports are divided into a first port group and a second port group, and coherent transmission can be performed between the transmission ports. Coherent transmission can be performed within the first port group, within the second port group, and between the first port group and the second port group.

[0358] In a possible design, the transmission ports are divided into a first port group and a second port group, coherent transmission can be performed within the first port group and within the second port group, and coherent transmission cannot be performed between the first port group and the second port group;

[0359] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset include 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, and the rows where the 1 non-zero element in each of the 4 precoding matrices is located are different;

[0360] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset;

[0361] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset;

[0362] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0363] In one possible design, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset including a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the rows of the first precoding matrix containing non-zero elements correspond to transmission ports included in the first port group; the rows of the second precoding matrix containing non-zero elements correspond to transmission ports included in the second port group.

[0364] In a possible design, coherent transmission cannot be performed between the transmission ports;

[0365] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, and the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements; the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different; the transmission power of the transmission port corresponding to the row containing the zero element is 0;

[0366] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset;

[0367] All precoding matrices of transmission rank 3 include a tenth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset;

[0368] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0369] In one possible design, when coherent transmission is possible between the transmission ports, the first bit field occupies 7 bits or 6 bits.

[0370] In a possible design, when coherent transmission is possible within the first port group and within the second port group but coherent transmission is not possible between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits.

[0371] In one possible design, when coherent transmission is not possible between the transmission ports, the first bit field occupies 4 bits.

[0372] In a possible design, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, -j.

[0373] In one possible design, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0374] In a possible design, the two transmission ports included in the first port group correspond to a dual-polarization antenna pair, or the two transmission ports included in the first port group correspond to two beams with the same beam direction but perpendicular polarization directions.

[0375] In a specific implementation, when the device 900 may be a base station in the above embodiment, the processing unit 901 is used to determine indication information, the indication information includes a first bit field, the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data stream on r transmission layers to obtain a signal sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices with a transmission rank of 1;

[0376] The transceiver unit 902 is used to send indication information to the terminal, where the indication information is used to enable the terminal to determine the precoding matrix for precoding the transmission data streams on all transmission layers.

[0377] In one possible design, coherent transmission can be performed between the transmission ports;

[0378] All precoding matrices with a transmission rank of 1 include at least a first precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the first precoding matrix subset include 4 non-zero elements; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, wherein the zero element indicates that the transmission power on the corresponding transmission port is 0; and the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different;

[0379] All precoding matrices with a transmission rank of 2 include a third precoding matrix subset, wherein a non-scalar part of each precoding matrix in the third precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0380] All precoding matrices with a transmission rank of 3 include a fourth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the fourth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three mutually orthogonal precoding matrices selected from the first precoding matrix subset;

[0381] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of 4 precoding matrices, and the 4 precoding matrices are all precoding matrices included in the second precoding matrix subset.

[0382] In one possible design, the third precoding matrix subset includes any two or three of the first type of precoding matrix, the second type of precoding matrix and the third type of precoding matrix; wherein the beam space of the first column and the second column of the first type of precoding matrix are exactly the same, but the cross-polarization phases are different; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are the same; the beam space of the first column and the second column of the second type of precoding matrix are opposite, but the cross-polarization phases are different.

[0383] In one possible design, the transmission ports are divided into a first port group and a second port group, and coherent transmission can be performed between the transmission ports. Coherent transmission can be performed within the first port group, within the second port group, and between the first port group and the second port group.

[0384] In a possible design, the transmission ports are divided into a first port group and a second port group, coherent transmission can be performed within the first port group and within the second port group, and coherent transmission cannot be performed between the first port group and the second port group;

[0385] All precoding matrices with a transmission rank of 1 include a fifth precoding matrix subset and a second precoding matrix subset, wherein the columns of each precoding matrix in the fifth precoding matrix subset include 2 non-zero elements and 2 zero elements, wherein the rows containing the non-zero elements correspond to transmission ports included in the first port group or the second port group; the rows containing the zero elements correspond to transmission ports with a transmission power of 0; the second precoding matrix subset includes 4 precoding matrices, wherein the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements, and the rows where the 1 non-zero element in each of the 4 precoding matrices is located are different;

[0386] All precoding matrices with a transmission rank of 2 include a sixth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the sixth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices selected from the fifth precoding matrix subset;

[0387] All precoding matrices with a transmission rank of 3 include a seventh precoding matrix subset, wherein the non-scalar part of each precoding matrix in the seventh precoding matrix subset is formed by merging the columns of the non-scalar parts of three precoding matrices, one of the three precoding matrices is a precoding matrix selected from the fifth precoding matrix subset, and the remaining two are two precoding matrices selected from the second precoding matrix subset;

[0388] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0389] In one possible design, all precoding matrices with a transmission rank of 2 also include an eighth precoding matrix subset, the eighth precoding matrix subset including a first precoding matrix and a second precoding matrix, the non-scalar parts of the first precoding matrix and the second precoding matrix are both formed by merging the columns of the non-scalar parts of the two precoding matrices, and the two precoding matrices are precoding matrices selected from the second precoding matrix subset; the rows of the first precoding matrix containing non-zero elements correspond to transmission ports included in the first port group; the rows of the second precoding matrix containing non-zero elements correspond to transmission ports included in the second port group.

[0390] In a possible design, coherent transmission cannot be performed between the transmission ports;

[0391] All precoding matrices with a transmission rank of 1 include a second precoding matrix subset, the second precoding matrix subset includes 4 precoding matrices, and the columns of each precoding matrix in the 4 precoding matrices include 1 non-zero element and 3 zero elements; the rows where the 1 non-zero element included in each of the 4 precoding matrices is located are different; the transmission power of the transmission port corresponding to the row containing the zero element is 0;

[0392] All precoding matrices with a transmission rank of 2 include a ninth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the ninth precoding matrix subset is formed by merging columns of non-scalar parts of two precoding matrices, and the two precoding matrices are two precoding matrices arbitrarily selected from the second precoding matrix subset;

[0393] All precoding matrices of transmission rank 3 include a tenth precoding matrix subset, wherein a non-scalar part of each precoding matrix in the tenth precoding matrix subset is formed by merging columns of non-scalar parts of three precoding matrices, and the three precoding matrices are three precoding matrices arbitrarily selected from the second precoding matrix subset;

[0394] The non-scalar part of the precoding matrix with a transmission rank of 4 is formed by merging the columns of the non-scalar parts of four precoding matrices, and the four precoding matrices are all precoding matrices of the second precoding matrix subset.

[0395] In one possible design, when coherent transmission is possible between the transmission ports, the first bit field occupies 7 bits or 6 bits.

[0396] In a possible design, when coherent transmission is possible within the first port group and within the second port group but coherent transmission is not possible between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits.

[0397] In one possible design, when coherent transmission is not possible between the transmission ports, the first bit field occupies 4 bits.

[0398] In a possible design, the non-zero elements included in each precoding matrix of the first precoding matrix set include part or all of 1, -1, j, -j.

[0399] In one possible design, in all precoding matrices of the first precoding matrix set, the 2-norm of rows containing non-zero elements is always 1 / 2.

[0400] In a possible design, the two transmission ports included in the first port group correspond to a dual-polarization antenna pair, or the two transmission ports included in the first port group correspond to two beams with the same beam direction but perpendicular polarization directions.

[0401] The specific implementation of the above-mentioned device embodiment corresponds to the method embodiment, and its specific implementation and beneficial effects are described in detail in the method embodiment.

[0402] Based on the same inventive concept, the embodiment of the present application further provides a circuit system, Figure 5 It is a schematic diagram of the structure of a circuit system provided in an embodiment of the present invention (for example, a communication device such as an access point or a base station, a station or a terminal).

[0403] like Figure 5 As shown, the circuit system 1200 can be implemented by a bus 1201 as a general bus architecture. According to the specific application of the circuit system 1200 and the overall design constraints, the bus 1201 can include any number of interconnected buses and bridges. The bus 1201 connects various circuits together, including a processor 1202, a storage medium 1203 and a bus interface 1204. Optionally, the circuit system 1200 uses the bus interface 1204 to connect a network adapter 1205 and the like via the bus 1201. The network adapter 1205 can be used to implement the signal processing function of the physical layer in the wireless communication network, and to transmit and receive radio frequency signals through the antenna 1207. The user interface 1206 can be connected to a user terminal, such as a keyboard, a display, a mouse or a joystick. The bus 1201 can also be connected to various other circuits, such as a timing source, a peripheral device, a voltage regulator or a power management circuit, etc. These circuits are well known in the art and are therefore not described in detail.

[0404] Alternatively, the circuit system 1200 may be configured as a chip or a system on a chip, which includes: one or more microprocessors providing processor functions; and an external memory providing at least a portion of the storage medium 1203, all of which are connected together with other supporting circuits via an external bus architecture.

[0405] Alternatively, the circuit system 1200 may be implemented using: an ASIC (application-specific integrated circuit) having a processor 1202, a bus interface 1204, a user interface 1206; and at least a portion of the storage medium 1203 integrated in a single chip, or the circuit system 1200 may be implemented using: one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits capable of performing the various functions described throughout the present invention.

[0406] Among them, processor 1202 is responsible for managing the bus and general processing (including executing software stored on storage medium 1203). Processor 1202 can be implemented using one or more general-purpose processors and / or special-purpose processors. Examples of processors include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Software should be broadly interpreted as representing instructions, data, or any combination thereof, regardless of whether it is called software, firmware, middleware, microcode, hardware description language, or other.

[0407] In the following figure, the storage medium 1203 is shown as being separated from the processor 1202, however, it is readily apparent to those skilled in the art that the storage medium 1203 or any portion thereof may be located outside the circuit system 1200. For example, the storage medium 1203 may include a transmission line, a carrier waveform modulated with data, and / or a computer product separated from a wireless node, all of which may be accessed by the processor 1202 through the bus interface 1204. Alternatively, the storage medium 1203 or any portion thereof may be integrated into the processor 1202, for example, may be a cache and / or a general register.

[0408] The processor 1202 may execute the method for indicating the uplink subband precoding matrix in any of the above embodiments of the present application, and the specific content will not be repeated here.

[0409] Figure 6 1 is another structural diagram of the circuit system of the embodiment of the present invention. The circuit system may be a processor. The processor may be embodied as a chip or a system on chip (SOC), which is arranged in a base station or a terminal of the wireless communication system of the embodiment of the present invention, so that the base station or the terminal implements the communication method of the embodiment of the present invention. Figure 6 As shown, the circuit system 60 includes: an interface unit 601, a control and operation unit 602, and a storage unit 603. Among them, the interface unit is used to communicate with other components of the base station or the terminal, the storage unit 603 is used to store computer programs or instructions, and the control and operation unit 602 is used to decode and execute these computer programs or instructions. It should be understood that these computer programs or instructions may include the above-mentioned terminal function program, and may also include the above-mentioned base station function program. When the terminal function program is decoded and executed by the control and operation unit 602, the terminal can implement the method for indicating the uplink subband precoding matrix in the embodiment of the present invention, and the functions of the terminal. When the base station function program is decoded and executed by the control and operation unit 602, the base station can implement the function of the base station in the method for indicating the uplink subband precoding matrix in the embodiment of the present invention.

[0410] In a possible design, these terminal function programs or base station function programs are stored in a memory outside the circuit system 60. When the terminal function program or base station function program is decoded and executed by the control and operation unit 602, the storage unit 603 temporarily stores part or all of the contents of the terminal function program or temporarily stores part or all of the contents of the base station function program.

[0411] In another optional implementation, these terminal function programs or base station function programs are set in a storage unit 603 stored inside the circuit system 60. When the terminal function program is stored in the storage unit 603 inside the circuit system 60, the circuit system 60 can be set in the terminal 200 of the wireless communication system of the embodiment of the present invention. When the base station function program is stored in the storage unit 603 inside the circuit system 60, the circuit system 60 can be set in the base station 100 of the wireless communication system of the embodiment of the present invention.

[0412] In yet another optional implementation, part of the contents of these terminal function programs or base station function programs are stored in a memory outside the circuit system 60 , and other parts of the contents of these terminal function programs or base station function programs are stored in a storage unit 603 inside the circuit system 60 .

[0413] Based on the same concept, the present application provides a computer-readable storage medium, in which instructions are stored. When the computer-readable storage medium is executed on a computer, the computer executes the method steps related to the terminal in various embodiments involved in the present application.

[0414] Based on the same concept, the present application provides a computer-readable storage medium, in which instructions are stored. When the computer-readable storage medium is executed on a computer, the computer executes the method steps related to the base station in various embodiments involved in the present application.

[0415] Based on the same concept, the present application provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the method steps related to the terminal in various embodiments of the present application.

[0416] Based on the same concept, the present application provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the method steps related to the base station in various embodiments of the present application.

[0417] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk Solid State Disk (SSD)), etc.

[0418] Those skilled in the art can clearly understand that the descriptions of the various embodiments provided in the present invention can refer to each other. For the convenience and conciseness of the description, the functions of the various devices and equipment provided in the embodiments of the present invention and the execution steps can refer to the relevant descriptions of the method embodiments of the present invention, and will not be repeated here.

[0419] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0420] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices (equipment), or computer program products. Therefore, the present application may adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware, which are collectively referred to as "modules" or "systems" herein. Moreover, the present application may adopt the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program codes. The computer program is stored / distributed in a suitable medium, provided together with other hardware or as a part of hardware, or may adopt other distribution forms, such as by Internet or other wired or wireless telecommunication systems.

[0421] Those skilled in the art may also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application may be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly demonstrate the interchangeability of hardware and software, the various illustrative components and steps described above have generally described their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for each specific application, but such implementation should not be understood as exceeding the scope of protection of the embodiments of the present invention.

[0422] The various illustrative logic blocks, modules and circuits described in the embodiments of the present application can be implemented or operated by a general processing unit, a digital signal processing unit, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination of the above. The general processing unit can be a microprocessing unit, and optionally, the general processing unit can also be any traditional processing unit, controller, microcontroller or state machine. The processing unit can also be implemented by a combination of computing devices, such as a digital signal processing unit and a microprocessing unit, a plurality of microprocessing units, one or more microprocessing units combined with a digital signal processing unit core, or any other similar configuration.

[0423] In one or more exemplary designs, the above functions described in the embodiments of the present invention can be implemented in hardware, software, firmware or any combination of the three. If implemented in software, these functions can be stored on a computer-readable medium, or transmitted in the form of one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media that facilitate the transfer of computer programs from one place to another. The storage medium can be any available medium that can be accessed by any general or special computer. For example, such computer-readable media can include but are not limited to RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program codes in the form of instructions or data structures and other forms that can be read by general or special computers, or general or special processing units. In addition, any connection can be appropriately defined as a computer-readable medium, for example, if the software is transmitted from a website site, server or other remote resource through a coaxial cable, fiber optic computer, twisted pair, digital subscriber line (DSL) or wirelessly, such as infrared, wireless and microwave, it is also included in the defined computer-readable medium. The disk and disc include compact disk, laser disk, optical disk, DVD, floppy disk and blue-ray disk. Disks usually copy data magnetically, while discs usually copy data optically with lasers. The above combination can also be included in computer readable media.

[0424] The above description of the specification of the present invention can make any technical personnel in the field use or implement the content of the present invention, and any modification based on the disclosed content should be considered obvious in the field. The basic principles described in the present invention can be applied to other variations without departing from the essence and scope of the invention of the present invention. Therefore, the content disclosed in the present invention is not limited to the described embodiments and designs, but can also be extended to the maximum scope consistent with the principles of the present invention and the disclosed new features.

Claims

1. A communication method, characterized in that: The method comprises: The terminal receives indication information sent by the base station, the indication information includes a first bit field, the first bit field is used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix is ​​used to precode the transmission data stream on r transmission layers to obtain a signal sent on N transmission ports of the terminal; the number of rows of the precoding matrix is ​​equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix is ​​equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank is equal to the number of transmission layers r; when r>1, the non-scalar part of the precoding matrix with a transmission rank of r in the first precoding matrix set is formed by merging the columns of the non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices whose transmission rank of any precoding matrix is ​​1; The terminal determines, according to the indication information, the precoding matrix for precoding transmission data streams on all transmission layers of the precoding matrices included in the first precoding matrix set; The first precoding matrix set includes a second precoding matrix set, a third precoding matrix set, a fourth precoding matrix set, and a fifth precoding matrix set; the transmission rank of any precoding matrix in the second precoding matrix set is 1, the transmission rank of any precoding matrix in the third precoding matrix set is 2, the transmission rank of any precoding matrix in the fourth precoding matrix set is 3, and the transmission rank of any precoding matrix in the fifth precoding matrix set is 4; Wherein, coherent transmission can be performed between any two transmission ports of the N transmission ports, or coherent transmission cannot be performed; The second precoding matrix set includes one or more first precoding matrices and one or more second precoding matrices, the columns of each first precoding matrix include 4 non-zero elements, the columns of each second precoding matrix include 1 non-zero element and 3 zero elements, the non-zero elements of any second precoding matrix are located in different rows, and the transmission power of the transmission port corresponding to the row of any second precoding matrix containing zero elements is 0; The third precoding matrix set includes one or more third precoding matrices, and the non-scalar part of each third precoding matrix is ​​formed by merging the columns of the non-scalar parts of two precoding matrices, and the two precoding matrices are selected from the one or more second precoding matrices; The non-scalar part of any one precoding matrix included in the fourth precoding matrix set is formed by merging columns of non-scalar parts of three precoding matrices, the three precoding matrices are three mutually orthogonal first precoding matrices selected from the one or more first precoding matrices, or selected from the one or more second precoding matrices, and any one precoding matrix included in the fourth precoding matrix set includes a fourth precoding matrix; The fifth precoding matrix set includes one or more fifth precoding matrices, and the non-scalar part of each fifth precoding matrix is ​​formed by merging the columns of the non-scalar parts of the four second precoding matrices; The fourth precoding matrix includes the following precoding matrix:

2. The method according to claim 1, characterized in that When coherent transmission or non-coherent transmission is performed between any two transmission ports of the N transmission ports, the third precoding matrix includes the following precoding matrix: or 3. The method according to claim 1, characterized in that When the N transmission ports are capable of coherent transmission, the first bit field occupies 7 bits or 6 bits; or, The N transmission ports are divided into a first port group and a second port group, and when two ports in the first port group can perform coherent transmission, and two ports in the second port group can perform coherent transmission, but coherent transmission cannot be performed between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits; or, When the N transmission ports are all unable to perform coherent transmission, the first bit field occupies 4 bits.

4. A communication method, characterized in that: The base station determines indication information, the indication information comprising a first bit field, the first bit field being used to indicate a precoding matrix included in a first precoding matrix set and a transmission rank corresponding to the precoding matrix, the precoding matrix being used to precode a transmission data stream on r transmission layers to obtain a signal sent on N transmission ports of a terminal; the number of rows of the precoding matrix being equal to the number of transmission ports N, and N=4; the number of columns of the precoding matrix being equal to the number of transmission layers r, 1≤r≤N, and the size of the transmission rank being equal to the number of transmission layers r; when r>1, a non-scalar part of a precoding matrix having a transmission rank of r in the first precoding matrix set is formed by merging columns of non-scalar parts of r precoding matrices, and the r precoding matrices are precoding matrices selected from all precoding matrices whose transmission rank of any precoding matrix is ​​1; The base station sends the indication information to the terminal; The first precoding matrix set includes a second precoding matrix set, a third precoding matrix set, a fourth precoding matrix set, and a fifth precoding matrix set; the transmission rank of any precoding matrix in the second precoding matrix set is 1, the transmission rank of any precoding matrix in the third precoding matrix set is 2, the transmission rank of any precoding matrix in the fourth precoding matrix set is 3, and the transmission rank of any precoding matrix in the fifth precoding matrix set is 4; Wherein, coherent transmission can be performed between any two transmission ports of the N transmission ports, or coherent transmission cannot be performed; The second precoding matrix set includes one or more first precoding matrices and one or more second precoding matrices, the columns of each first precoding matrix include 4 non-zero elements, the columns of each second precoding matrix include 1 non-zero element and 3 zero elements, the non-zero elements of any second precoding matrix are located in different rows, and the transmission power of the transmission port corresponding to the row of any second precoding matrix containing zero elements is 0; The third precoding matrix set includes one or more third precoding matrices, and the non-scalar part of each third precoding matrix is ​​formed by merging the columns of the non-scalar parts of two precoding matrices, and the two precoding matrices are selected from the one or more second precoding matrices; The non-scalar part of any one precoding matrix included in the fourth precoding matrix set is formed by merging columns of non-scalar parts of three precoding matrices, the three precoding matrices are three mutually orthogonal first precoding matrices selected from the one or more first precoding matrices, or selected from the one or more second precoding matrices, and any one precoding matrix included in the fourth precoding matrix set includes a fourth precoding matrix; The fifth precoding matrix set includes one or more fifth precoding matrices, and the non-scalar part of each fifth precoding matrix is ​​formed by merging the columns of the non-scalar parts of the four second precoding matrices; The fourth precoding matrix includes the following precoding matrix:

5. The method according to claim 4, characterized in that The third precoding matrix includes the following precoding matrix: or 6. The method according to claim 4, characterized in that When the N transmission ports are capable of coherent transmission, the first bit field occupies 7 bits or 6 bits; or, The N transmission ports are divided into a first port group and a second port group, and when two ports in the first port group can perform coherent transmission, and two ports in the second port group can perform coherent transmission, but coherent transmission cannot be performed between the first port group and the second port group, the first bit field occupies 6 bits or 5 bits; or, When the N transmission ports are all unable to perform coherent transmission, the first bit field occupies 4 bits.

7. A terminal, characterized in that: The terminal comprises: Memory for storing computer programs; A processor, configured to call a computer program in the memory to execute the method according to any one of claims 1 to 3.

8. The terminal according to claim 7, characterized in that: The terminal includes user equipment.

9. A base station, characterized in that: The base station comprises: Memory for storing computer programs; A processor, configured to call a computer program in the memory to execute a method as described in any one of claims 4 to 6.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is stored in a terminal, and the computer-readable storage medium includes a computer program. When the computer program is executed, the method according to any one of claims 1 to 3 is implemented.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium is stored in a base station, and the computer-readable storage medium includes a computer program. When the computer program is executed, the method according to any one of claims 4 to 6 is implemented.

12. A computer program product, characterized in that When the computer program product is executed, the method according to any one of claims 1 to 3 is implemented.

13. A computer program product, characterized in that When the computer program product is executed, the method according to any one of claims 4 to 6 is implemented.

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