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US-12621022-B2 - Method for transmitting signal using port virtualization matrix, and electronic device performing method

US12621022B2US 12621022 B2US12621022 B2US 12621022B2US-12621022-B2

Abstract

A base station is provided. The base station includes a transceiver configured to exchange data with an external device, memory storing one or more computer programs, and one or more processors communicatively coupled to the transceiver and the memory, wherein the one or more computer programs include computer-executable instructions that, when executed by the one or more processors, cause the base station to generate a channel state indicator-reference signal (CSI-RS) to be transmitted to a user terminal through a plurality of antennas of the base station, transmit a test signal generated by applying an initial port virtualization matrix to the CSI-RS to the user terminal through a transceiver, receive, from the user terminal, rank information for channels to which the initial port virtualization matrix is applied and information about a target precoding matrix for the channels, obtain partial channel information on the basis of an sounding reference signal (SRS) received from the user terminal, and generate a target port virtualization matrix on the basis of the rank information, the target precoding matrix, and the partial channel information.

Inventors

  • Chaehee LIM
  • Soo Yong Choi
  • Dong Heon Lee
  • Seong Yeop JOUNG

Assignees

  • SAMSUNG ELECTRONICS CO., LTD.
  • UIF (UNIVERSITY INDUSTRY FOUNDATION), YONSEI UNIVERSITY

Dates

Publication Date
20260505
Application Date
20240306
Priority Date
20210906

Claims (16)

  1. 1 . A base station comprising: a transceiver configured to exchange data with an external device; memory storing one or more computer programs; and one or more processors communicatively coupled to the transceiver and the memory, wherein the one or more computer programs include computer-executable instructions that, when executed by the one or more processors, cause the base station to: generate a channel state information-reference signal (CSI-RS) to be transmitted to a user terminal through a plurality of antennas of the transceiver, transmit a test signal generated by applying an initial port virtualization matrix to the CSI-RS to the user terminal through the transceiver, wherein the test signal is propagated to the user terminal through channels between the plurality of antennas of the transceiver and one or more antennas of the user terminal, receive, from the user terminal through the transceiver, rank information for the channels to which the initial port virtualization matrix is applied and information about a target precoding matrix for the channels, obtain partial channel information based on a sounding reference signal (SRS) received from the user terminal through the transceiver, and generate a target port virtualization matrix based on the rank information, the target precoding matrix, and the partial channel information, wherein the target port virtualization matrix is used by the base station to transmit data to the user terminal, and wherein the information about the target precoding matrix for the channels is calculated based on the following equation: PMI = argmax i = 1 , … , M ⁢ ∑ j = 1 , … , r log ( 1 + ❘ "\[LeftBracketingBar]" R j H ⁢ HV csi ⁢ W i , j ❘ "\[RightBracketingBar]" 2 ∑ k ≠ j ❘ "\[LeftBracketingBar]" R j H ⁢ HV csi ⁢ W i , k ❘ "\[RightBracketingBar]" + σ 2 ) , in the equation, a precoding matrix indicator (PMI) is the information about the target precoding matrix, M is a number of a plurality of precoding matrices in a precoding codebook, the matrix W is one of the plurality of precoding matrices, a matrix HV csi denotes a port virtualization matrix V csi to which a matrix H representing the channels is applied, the matrix R denotes a receiver matrix of the user terminal, r is a rank of the matrix H, and σ is a preset value.
  2. 2 . The base station of claim 1 , wherein the initial port virtualization matrix and the target port virtualization matrix are matrices to map the plurality of antennas and one or more ports that are fewer than the plurality of antennas.
  3. 3 . The base station of claim 1 , wherein the one or more computer programs further include computer-executable instructions that, when executed by the one or more processors, cause the base station to: determine the target port virtualization matrix among a plurality of candidate port virtualization matrices in a pre-generated port virtualization codebook based on the rank information, the target precoding matrix, and the partial channel information.
  4. 4 . The base station of claim 3 , wherein the one or more computer programs further include computer-executable instructions that, when executed by the one or more processors, cause the base station to: input the rank information, the target precoding matrix, and the partial channel information to a pre-trained port virtualization matrix generation model, and obtain the target port virtualization matrix among the plurality of candidate port virtualization matrices in the port virtualization codebook as a result of the inputting.
  5. 5 . The base station of claim 3 , wherein the one or more computer programs further include computer-executable instructions that, when executed by the one or more processors, cause the base station to: generate a set of arbitrary basic matrices having a preset size; and generate the port virtualization codebook by selecting a portion of the set of arbitrary basic matrices.
  6. 6 . The base station of claim 1 , wherein the one or more computer programs further include computer-executable instructions that, when executed by the one or more processors, cause the base station to: generate the target port virtualization matrix by inputting the rank information, the target precoding matrix, and the partial channel information to a pre-trained port virtualization matrix generation model.
  7. 7 . The base station of claim 1 , wherein elements of the target port virtualization matrix are “0” or “1”.
  8. 8 . The base station of claim 1 , wherein elements of the target port virtualization matrix are a combination of exponential functions.
  9. 9 . A signal transmission method for wireless communication, performed by a base station, the signal transmission method comprising: generating, by the base station, a channel state information-reference signal (CSI-RS) to be transmitted to a user terminal through a plurality of antennas of a transceiver of a base station; transmitting, by the base station, a test signal generated by applying an initial port virtualization matrix to the CSI-RS to the user terminal, wherein the test signal is propagated to the user terminal through channels between the plurality of antennas of the transceiver and one or more antennas of the user terminal; receiving, by the base station from the user terminal, rank information for the channels to which the initial port virtualization matrix is applied and information about a target precoding matrix for the channels; obtaining, by the base station, partial channel information based on a sounding reference signal (SRS) received from the user terminal; generating, by the base station, a target port virtualization matrix based on the rank information, the target precoding matrix, and the partial channel information; and transmitting, by the base station, a data signal to the user terminal using the target port virtualization matrix, wherein the information about the target precoding matrix for the channels is calculated based on the following equation: PMI = argmax i = 1 , … , M ⁢ ∑ j = 1 , … , r log ( 1 + ❘ "\[LeftBracketingBar]" R j H ⁢ HV csi ⁢ W i , j ❘ "\[RightBracketingBar]" 2 ∑ k ≠ j ❘ "\[LeftBracketingBar]" R j H ⁢ HV csi ⁢ W i , k ❘ "\[RightBracketingBar]" + σ 2 ) , in the equation, a precoding matrix indicator (PMI) is the information about the target precoding matrix, M is a number of a plurality of precoding matrices in a precoding codebook, a matrix W is one of the plurality of precoding matrices, a matrix HV csi denotes a port virtualization matrix V csi to which a matrix H representing the channels is applied, the matrix R denotes a receiver matrix of the user terminal, r is a rank of the matrix H, and o is a preset value.
  10. 10 . The signal transmission method of claim 9 , wherein the initial port virtualization matrix and the target port virtualization matrix are matrices to map the plurality of antennas and one or more ports that are fewer than the plurality of antennas.
  11. 11 . The signal transmission method of claim 9 , wherein the generating of the target port virtualization matrix comprises: determining the target port virtualization matrix among a plurality of candidate port virtualization matrices in a pre-generated port virtualization codebook based on the rank information, the target precoding matrix, and the partial channel information.
  12. 12 . The signal transmission method of claim 9 , wherein the generating of the target port virtualization matrix comprises: generating the target port virtualization matrix by inputting the rank information, the target precoding matrix, and the partial channel information to a pre-trained port virtualization matrix generation model.
  13. 13 . The signal transmission method of claim 9 , wherein elements of the target port virtualization matrix are “0” or “1”.
  14. 14 . The signal transmission method of claim 9 , wherein elements of the target port virtualization matrix are a combination of exponential functions.
  15. 15 . One or more non-transitory computer-readable storage media storing one or more computer programs including computer-executable instructions that, when executed by one or more processors of a base station, cause the base station to perform operations, the operations comprising: generating, by the base station, a channel state information-reference signal (CSI-RS) to be transmitted to a user terminal through a plurality of antennas of a transceiver of a base station; transmitting, by the base station, a test signal generated by applying an initial port virtualization matrix to the CSI-RS to the user terminal, wherein the test signal is propagated to the user terminal through channels between the plurality of antennas of the transceiver and one or more antennas of the user terminal; receiving, by the base station from the user terminal, rank information for the channels to which the initial port virtualization matrix is applied and information about a target precoding matrix for the channels; obtaining, by the base station, partial channel information based on a sounding reference signal (SRS) received from the user terminal; generating, by the base station, a target port virtualization matrix based on the rank information, the target precoding matrix, and the partial channel information; and transmitting, by the base station, a data signal to the user terminal using the target port virtualization matrix, wherein the information about the target precoding matrix for the channels is calculated based on the following equation: PMI = argmax i = 1 , … , M ⁢ ∑ j = 1 , … , r log ( 1 + ❘ "\[LeftBracketingBar]" R j H ⁢ HV csi ⁢ W i , j ❘ "\[RightBracketingBar]" 2 ∑ k ≠ j ❘ "\[LeftBracketingBar]" R j H ⁢ HV csi ⁢ W i , k ❘ "\[RightBracketingBar]" + σ 2 ) , in the equation, a precoding matrix indicator (PMI) is the information about the target precoding matrix, M is a number of a plurality of precoding matrices in a precoding codebook, a matrix W is one of the plurality of precoding matrices, a matrix HV csi denotes a port virtualization matrix V csi to which a matrix H representing the channels is applied, the matrix R denotes a receiver matrix of the user terminal, r is a rank of the matrix H, and σ is a preset value.
  16. 16 . The one or more non-transitory computer-readable storage media of claim 15 , wherein the initial port virtualization matrix and the target port virtualization matrix are matrices to map the plurality of antennas and one or more ports that are fewer than the plurality of antennas.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application is a continuation application, claiming priority under § 365(c), of an International application No. PCT/KR2022/011183, filed on Jul. 29, 2022, which is based on and claims the benefit of a Korean patent application number 10-2021-0118603, filed on Sep. 6, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. JOINT RESEARCH AGREEMENT The disclosure was made by or on behalf of the below listed parties to a joint research agreement. The joint research agreement was in effect on or before the date the disclosure was made and the disclosure was made as a result of activities undertaken within the scope of the joint research agreement. The parties to the joint research agreement are 1) SAMSUNG ELECTRONICS CO., LTD. and 2) UIF (University Industry Foundation), Yonsei University. BACKGROUND 1. Field The disclosure relates to signal transmission technology for wireless communication. More particularly, the disclosure relates to signal transmission technology using a port virtualization matrix. 2. Description of Related Art A multi user-multi input multi output (MU-MIMO) system may increase spectral efficiency by transmitting signals to multiple users within the same time-frequency resources through spatial multiplexing. The spatial multiplexing method performs preprocessing that reflects the channel states on data to be transmitted. Data is transferred to a channel state indicator-reference signal (CSI-RS) port through a port precoder, the transferred data is transferred to an antenna element through a port virtualization matrix, and the antenna element transmits the data. The port precoder is designed by receiving feedback on a value suitable for an effective channel measured by a user terminal from the user terminal. Since information about a port virtualization matrix is included in the effective channel measured by the user terminal, an appropriate port virtualization matrix needs to be designed to improve data transmission performance. The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure. SUMMARY A base station's transmitting a channel state indicator-reference signal (CSI-RS) multiple times to design an optimal port virtualization matrix consumes resources, and thus, it is difficult for a base station having insufficient channel information to design an optimal port virtualization matrix. Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a method of transmitting a CSI-RS a small number of times and generating a port virtualization matrix based on the same. Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments. In accordance with an aspect of the disclosure, a base station is provided. The base station includes a transceiver configured to exchange data with an external device, memory storing one or more computer programs and one or more processors communicatively coupled to the transceiver and the memory, wherein the one or more computer programs include computer-executable instructions that, when executed by the one or more processors, cause the base station to generate a channel state information-reference signal (CSI-RS) to be transmitted to a user terminal through a plurality of antennas of the c transceiver, transmit a test signal generated by applying an initial port virtualization matrix to the CSI-RS to the user terminal through the transceiver, wherein the test signal is propagated to the user terminal through channels between the plurality of antennas of the transceiver and one or more antennas of the user terminal, receive, from the user terminal through the transceiver, rank information for the channels to which the initial port virtualization matrix is applied and information about a target precoding matrix for the channels, obtain partial channel information based on a sounding reference signal (SRS) received from the user terminal through the transceiver, and generate a target port virtualization matrix based on the rank information, the target precoding matrix, and the partial channel information, wherein the target port virtualization matrix may be used by the base station to transmit data to the user terminal. In accordance with another aspect of the disclosure, a signal transmission method for wireless communication, performed by a base station is provided. The signal transmission method includes generating, by the base station, a CSI-RS to be transmitted to