# US 2019/0356367 A1 · Beamforming-Based Transmission Method and Apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0356367 A1 - Document ID: US20190356367A1 - Status: Published application - Kind: A1 - Application number: 16/338,641 - Filed: 2016-09-30 - Published: 2019-11-21 - Earliest claimed: 2016-09-30 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Yanliang Sun; Bin Liu - Web page: https://patentgrep.com/patent/US20190356367A1 ## CPC - H04B 7/0617: {for beam forming} - H04B 7/0469: {taking special antenna structures, e.g. cross polarized antennas into account} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0634: {Antenna weights or vector/matrix coefficients} - H04W 72/20: Control channels or signalling for resource management - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method includes obtaining, by a terminal, a quantity M of beamforming vectors needing to be reported by the terminal and a first reference signal that are sent by a base station; estimating downlink channel states on N dual-polarized antenna ports based on the first reference signal; selecting m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported that is sent by the base station; and feeding back the m selected first beamforming codewords and ranks of the downlink channel states to the base station. ## Claims ### Claim 1 A beam forming-based transmission method by a terminal, the method comprising: obtaining, from a base station, a first reference signal and a message indicating a quantity M of beamforming vectors needing to be reported by the terminal, wherein the first reference signal is received from N dual-polarized antenna ports of the base station, and wherein M and N each are an integer greater than zero; estimating downlink channel states on the N dual-polarized antenna ports based on the first reference signal; selecting m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported, wherein m≤M; and feeding back to the base station the m first beamforming codewords and ranks of the downlink channel states. ### Claim 2 (depends on 1) The method of claim 1, further comprising determining a quantity m of the m first beamforming codewords by determining the quantity M of beamforming vectors needing to be reported as the quantity m of the m first beamforming codewords. ### Claim 3 (depends on 1) The method of claim 1, wherein the terminal determines a quantity m of the m first beamforming codewords at least in part by: determining, by the terminal, the quantity m of the m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported so that channel quality after joint precoding of m optimal beamforming vectors is optimal; and feeding back, by the terminal, a value of m to the base station. ### Claim 4 (depends on 2) The method of claim 2, wherein after the feeding back, by the terminal, the m first beamforming codewords and ranks of the downlink channel states to the base station, the method further comprises: calculating, by the terminal, a channel quality indicator based on the m first beamforming codewords and the ranks of the downlink channel states; and feeding back the channel quality indicator to the base station. ### Claim 5 (depends on 4) The method of claim 4, wherein after the feeding back, by the terminal, the channel quality indicator to the base station, the method further comprises: obtaining, by the terminal from the base station, a second reference signal and data, wherein the data is received from k antenna ports of the base station, and wherein k is a positive integer greater than zero; estimating, by the terminal, downlink channel states on the k antenna ports based on the second reference signal; and decoding, through precoding, a data channel based on ranks of the downlink channel states. ### Claim 6 (depends on 2) The method of claim 2, wherein after the feeding back, by the terminal, the m first beamforming codewords and ranks of the downlink channel states to the base station, the method further comprises: obtaining, by the terminal, a second reference signal from p antenna ports of the base station; estimating, by the terminal, downlink channel states on the p antenna ports based on the second reference signal; selecting q antenna ports from the p antenna ports based on the downlink channel states; calculating a channel quality indicator; and feeding back sequence numbers of the q antenna ports and the channel quality indicator to the base station, wherein q≤p, and p is equal to m or p is equal to 2 m. ### Claim 7 (depends on 6) The method of claim 6, wherein after the feeding back, by the terminal, sequence numbers of the q antenna ports and the channel quality indicator to the base station, the method further comprises: obtaining, by the terminal from the base station, a third reference signal and data, wherein the data is received from the base station on k antenna ports; estimating, by the terminal, downlink channel states on the k antenna ports based on the third reference signal; and decoding, through preceding, a data channel based on ranks of the downlink channel states. ### Claim 8 A beam forming-based transmission method by a base station, the method comprising: obtaining first feedback information of a terminal, wherein the first feedback information of the terminal comprises m first beamforming codewords selected by the terminal; determining m second beamforming codewords of the base station based on the m first beamforming codewords selected by the terminal; performing beamforming for an antenna group in each polarization direction based on the m second beamforming codewords of the base station; generating p antenna ports, wherein antennas in the antenna group in the polarization direction have a same polarization direction, and p is equal to m or p is equal to 2 m; and sending a second reference signal to the terminal on the p antenna ports. ### Claim 9 A beam forming-based transmission method by a terminal, the method comprising; obtaining, from a base station, a first reference signal and a message indicating a quantity M of beamforming vectors needing to be reported by the terminal wherein the first reference signal is received from L antenna ports of the base station, wherein M and L each are an integer greater than zero, and wherein L>M; estimating downlink channel states on the L antenna ports based on the first reference signal; selecting m antenna ports from the 1, antenna ports as beamforming vectors needing to be reported based on the downlink channel states and the quantity M of beamforming vectors needing to be reported; calculating a channel quality indicator, wherein m≤M; and feeding back to the base station sequence numbers of the m antenna ports, the channel quality indicator, and ranks of the downlink channel states. ### Claim 10 (depends on 9) The method of claim 9, wherein after the feeding back, by the terminal, the sequence numbers of the m antenna ports, the channel quality indicator, and the ranks of the downlink channel states to the base station, the method further comprises: obtaining, by the terminal from the base station, a second reference signal and data, wherein the data is received from k antenna ports of the base station; estimating, by the terminal, downlink channel states on the k antenna ports based on the second reference signal; and decoding, through preceding, a data channel based on ranks of the downlink channel slates, wherein k is a positive integer greater than zero. ### Claim 11 (depends on 9) The method of claim 9, wherein the terminal determines a quantity m of the m antenna ports selected from the L antenna ports by determining the quantity M of beamforming vectors needing to be reported as the quantity m of the antenna ports selected from the L antenna ports. ### Claim 12 (depends on 9) The method of claim 9, wherein the terminal determines a quantity m of the m antenna ports selected from the L antenna ports at least in part by: determining, by the terminal, the quantity m of the m antenna ports based on the downlink channel states and the quantity M of beamforming vectors needing to be reported so that channel quality after joint precoding of m optimal beamforming vectors is optimal; and feeding back, by the terminal, a selected value of m to the base station. ### Claim at position 13 13-26. (canceled) ### Claim 27 A beam forming-based transmission device comprising: a memory storing information; a transceiver configured to obtain, from a base station, a first reference signal and a message indicating a quantity M of beamforming vectors needing to be reported wherein the first reference signal is received from N dual-polarized antenna ports of the base station, and wherein M and N each are an integer greater than zero; and a processor coupled to the memory and the transceiver and configured to read the information to: estimate downlink channel states on the N dual-polarized antenna ports based on the first reference signal obtained by the transceiver; and select m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported, where m≤M, and wherein the transceiver is further configured to feed back, to the base station, the m first beamforming codewords selected by the processor and ranks of the downlink channel states. ### Claim 28 (depends on 27) The beam forming-based transmission device of claim 27, wherein the processor is configured to determine the quantity M of beamforming vectors needing to be reported as a quantity m of the m first beamforming codewords. ### Claim 29 (depends on 27) The beamforming-based transmission device of claim 27, wherein the processor is configured to determine a quantity m of the m first beamforming codewords based on the downlink channel suites and the quantity M of beamforming vectors needing to be reported so that channel quality after joint precoding of m optimal beamforming vectors is optimal, and wherein the processor is further configured to feed back a value of m to the base station using the transceiver. ### Claim 30 (depends on 28) The beamforming-based transmission device of claim 28, wherein after the processor feeds back the m first beamforming codewords and ranks of the downlink channel states to the base station, the processor is further configured to: calculate a channel quality indicator based on the m first beamforming codewords and the ranks of the downlink channel states; and feed back the channel quality indicator to the base station. ### Claim 31 (depends on 30) The beamforming-based transmission device of claim 30, wherein after the processor feeds back the channel quality indicator to the base station, the processor is further configured to: obtain, from the base station, a second reference signal; obtain data from k antenna ports of the base station; estimate downlink channel states on the k antenna ports based on the second reference signal; and decode, through precoding, a data channel based on ranks of the downlink channel states, wherein k is a positive integer greater than zero. ### Claim 32 (depends on 28) The beamforming-based transmission device of claim 28, wherein after the processor feeds back the m first beamforming codewords and ranks of the downlink channel states to the base station, the processor is further configured to: obtain, using the transceiver and from the base station, a second reference signal and data, wherein the data is received from p antenna ports of the base station; estimate downlink channel states on the p antenna ports based on the second reference signal; select q antenna ports from the p antenna ports based on the downlink channel states; calculate a channel quality indicator; and feed back sequence numbers of the q antenna ports and the channel quality indicator to the base station, wherein q