# US 8,274,937 B2 · Method and apparatus for beamforming in OFDM wireless system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,274,937 B2 - Document ID: US8274937B2 - Status: Granted - Kind: B2 - Application number: 12/455,689 - Filed: 2009-06-05 - Published: 2010-03-04 - Granted: 2012-09-25 - Earliest claimed: 2008-08-26 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Jiann-An Tsai - Web page: https://patentgrep.com/patent/US8274937B2 ## CPC - H04B 7/0417: Feedback systems - H04B 7/0408: using two or more beams, i.e. beam diversity - H04B 7/0452: Multi-user MIMO systems - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0634: {Antenna weights or vector/matrix coefficients} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/0469: {taking special antenna structures, e.g. cross polarized antennas into account} - H04B: TRANSMISSION ## Abstract Systems and methods are disclosed for use in a wireless network that promotes simultaneous beamforming. These systems and methods include determining the Channel Quality Indicator (CQI) and Best Beam Index (BBI) for communications between a plurality of mobile stations and a base station, ranking the plurality of mobile stations in a list according to the determined CQI and BBI, and selecting a subset of the plurality of mobile stations for simultaneous beamformed communications. These systems and methods may also include verifying that the selected subset of the plurality of mobile stations does not have a conflict and initiating beamformed communications. Certain embodiments of the BBI may be determined based on a predetermined codebook, which is a function of an antenna configuration, such as a uniform linear array (ULA) and a uniform circular array (UCA). ## Claims ### Claim 1 For use in a wireless network, a method of performing simultaneously beamforming, the method comprising: determining the Channel Quality Indicator (CQI) for communications between a plurality of mobile stations and a base station; ranking the plurality of mobile stations in a list according to the determined CQI; selecting a subset of the plurality of mobile stations for simultaneous beamformed communications; verifying the selected subset of the plurality of mobile stations do not have a conflict; and initiating beamformed communications. ### Claim 2 (depends on 1) The method as set forth in claim 1, further comprising the selecting a codebook for use in beamforming, wherein the codebook comprises the following equation as a subset of the codebook design: C j = ⁢ [ w 1 ⁡ ( θ j ) w 2 ⁡ ( θ j ) ⋮ w P ⁡ ( θ j ) ] = [ 1 ⅇ - j2π ⁢ D λ ⁢ sin ⁡ ( θ j ) ⅇ - j2π ⁢ 2 ⁢ D λ ⁢ sin ⁡ ( θ j ) ⋮ ⅇ - j2π ⁢ ( P - 1 ) ⁢ D λ ⁢ sin ⁡ ( θ j ) ] / P . ### Claim 3 (depends on 2) The method of claim 2, wherein said codebook is selected on the basis of an antenna configuration. ### Claim 4 (depends on 3) The method of claim 3, wherein said antenna configuration is a linear antenna configuration. ### Claim 5 (depends on 4) The method of claim 4, wherein said upon detecting a conflict between two mobile station, the mobile station with the lowest CQI is removed from beamforming communications. ### Claim 6 (depends on 1) The method as set forth in claim 1, further comprising the selecting a codebook for use in beamforming, wherein the codebook comprises the following equation as a subset of the codebook design: C j = [ w 1 ⁡ ( θ j ) w 2 ⁡ ( θ j ) ⋮ w P ⁡ ( θ j ) ] = [ 1 ⅇ - j2π ⁢ R λ ⁢ sin ⁡ ( ζ ) ⁢ cos ⁡ ( θ j - ϕ 1 ) ⅇ - j2π ⁢ R λ ⁢ sin ⁡ ( ζ ) ⁢ cos ⁡ ( θ j - ϕ 2 ) ⋮ ⅇ - j2π ⁢ R λ ⁢ sin ⁡ ( ζ ) ⁢ cos ⁡ ( θ j - ϕ P ) ] / P . ### Claim 7 (depends on 1) The method of claim 1, wherein said plurality of mobile stations receive a plurality of beamformed communications from the base station. ### Claim 8 (depends on 1) The method of claim 1, wherein the subset of mobile stations comprises at least two mobile stations. ### Claim 9 A wireless network comprising a plurality of mobile stations, the network comprising: a first mobile station capable of beamformed communication with a first base station; and a second mobile station capable of simultaneous beamformed communications with the first base station, wherein at least one of the first and second mobile stations transmit information to the base station that promotes the simultaneous beamformed communication between the first mobile station and the base station. ### Claim 10 (depends on 9) The wireless network as set forth in claim 9, wherein the information transmitted by at least one of the first and second mobile station includes CQI information. ### Claim 11 (depends on 10) The wireless network as set forth in claim 10, wherein both the first and second mobile station transmit information to the base station. ### Claim 12 (depends on 9) The wireless network as set forth in claim 9, wherein the information transmitted by the at least one first and second mobile station includes CQI channel estimation different between a dedicated pilot and a common pilot. ### Claim 13 (depends on 9) The wireless network as set forth in claim 9, wherein both the first and second mobile station transmit a single codeword as a feedback to the base station. ### Claim 14 (depends on 13) The wireless network as set forth in claim 13, wherein upon the determination of a conflict between the first and second mobile station, beamforming is only performed with the mobile station with the highest CQI. ### Claim 15 (depends on 9) The wireless network as set forth in claim 9, further comprising a third mobile station that transmits information to the base station. ### Claim 16 (depends on 15) The wireless network as set forth in claim 15, wherein beamforming is performed using the third mobile station and one of the at least one of the first mobile station and the second mobile station. ### Claim 17 For use in a wireless network, a base station capable of simultaneous beamformed communication with a plurality of mobile devices, the base station comprising: a computer readable medium comprising information related to at least one codebook that corresponds to an antenna configuration of the base station; a processor configured to access the computer readable medium and use the at least one codebook to provide simultaneous communication with a plurality of mobile stations; and a transceiver coupled to the processor; wherein the transceiver comprises a plurality of transmit antennas and is configured to receive information from a plurality of mobile stations and transfer this information to the processor, and wherein the processor is configured to interpret the information, select a subset of mobile stations for simultaneous beamforming, and instruct the transceiver to allow for simultaneous beamforming with a plurality of mobile stations. ### Claim 18 (depends on 17) The base station of claim 17, wherein the information comprises CQI information. ### Claim 19 (depends on 18) The base station of claim 18, wherein the information is used to rank the mobile stations. ### Claim 20 (depends on 19) The method as set forth in claim 19, wherein the information is used to ensure that the plurality of mobile stations for beamforming do not use the same transmit antenna.