# US 12,009,891 B2 · Codebook design for composite beamforming in next-generation mmWave systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,891 B2 - Document ID: US12009891B2 - Status: Granted - Kind: B2 - Application number: 17/948,624 - Filed: 2022-09-20 - Published: 2023-03-23 - Granted: 2024-06-11 - Earliest claimed: 2021-09-22 - Assignees: NEC Corporation - Applicants: NEC Laboratories America, Inc. - Inventors: Mohammad Khojastepour; Nariman Torkzaban - Web page: https://patentgrep.com/patent/US12009891B2 ## CPC - H01Q 3/38: the phase-shifters being digital - H04B 7/0617: {for beam forming} - H01Q 3/2605: {Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H01Q 21/08: the units being spaced along or adjacent to a rectilinear path {(waveguide fed H01Q21/0037)} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - H04B: TRANSMISSION ## Abstract A method of communicating between a transmitter and a receiver in a wireless communication system is provided. The method includes selecting a beamformer from a beamforming codebook. The method further includes transmitting a signal from antenna elements using the selected beamformer by adjusting a gain and a phase of the signal. The antenna elements correspond to an absolute value and an angle of a respective complex beamforming coefficient from the selected beamformer. The beamformer is a composite beam including a plurality of disjoint beam lobes, and each of the plurality of disjoint beam lobes covers a desired angular interval. ## Claims ### Claim 1 A method of communicating between a transmitter and a receiver in a wireless communication system, comprising: selecting a beamformer from a beamforming codebook; and transmitting a signal from antenna elements using the selected beamformer by adjusting a gain and a phase of the signal, the antenna elements corresponding to an absolute value and an angle of a respective complex beamforming coefficient from the selected beamformer, wherein the respective complex beamforming coefficient is obtained by: calculating beamforming coefficients of the antenna elements for a composite beam as a summation of beamforming coefficients of corresponding ones of the antenna elements of a beamforming vector for the plurality of disjoint beam lobes of the composite beam; and normalizing the beamforming vector of the calculated beamforming coefficients such that an absolute value of an m-th beamforming coefficient of the beamforming vector for a constituent beam lobe q is proportional to sinc(δq(η+m)), wherein δq and n are two constant values and sinc(x) is a function defined as sin(x)/x, where sin(x) is the sinusoidal function; wherein the beamformer is a composite beam comprised of a plurality of disjoint beam qlobes, and each of the plurality of disjoint beam lobes covers a desired angular interval. ### Claim 2 (depends on 1) The method of claim 1, wherein the antenna elements are arranged in tandem in two parallel lines of a particular distance, and wherein the antenna elements in a line from among the two parallel lines are uniformly placed. ### Claim 3 (depends on 2) The method of claim 2, wherein the antenna elements are dipole or cross-dipole or patch antennas. ### Claim 4 (depends on 2) The method of claim 2, wherein the beamforming coefficients of tandem ones of the antenna elements have a same absolute value. ### Claim 5 (depends on 4) The method of claim 4, wherein a difference in a phase of tandem ones of the antenna elements is set to achieve a desired isolation between a radiated signal in unwanted directions and intended directions. ### Claim 6 (depends on 1) The method of claim 1, wherein the beamforming codebook is a hierarchical codebook comprising: a first layer codebook which is comprised of plurality of beamforming codewords for a given set of beams; and a second layer codebook which is comprised of plurality of index sets, wherein an index set denotes a composition of a composite codebook in terms of its constituent beams. ### Claim 7 (depends on 1) The method of claim 1, wherein an absolute value of beamforming coefficients of a beamforming codeword is constant. ### Claim 8 (depends on 1) The method of claim 1, wherein a codeword of the beamforming codebook can be decomposed as a linear summation of a particular number of phase vectors, wherein a phase vector is a vector for which an absolute value of the elements of the vector is constant. ### Claim 9 A base station in a wireless communication system, comprising: a memory device for storing program code; and a hardware processor operatively coupled to the memory device for running the program code to: select a beamformer from a beamforming codebook; and transmit a signal from antenna elements using the selected beamformer by adjusting a gain and a phase of the signal, the antenna elements corresponding to an absolute value and an angle of a respective complex beamforming coefficient from the selected beamformer, wherein the respective complex beamforming coefficient is obtained by the hardware processor by: calculating beamforming coefficients of the antenna elements for a composite beam as a summation of beamforming coefficients of corresponding ones of the antenna elements of a beamforming vector for the plurality of disjoint beam lobes of the composite beam; and normalizing the beamforming vector of the calculated beamforming coefficients such that an absolute value of an m-th beamforming coefficient of the beamforming vector for a constituent beam lobe q is proportional to sinc(δq(n+m)), wherein δq and η are two constant values and sinc(x) is a function defined as sin(x)/x, where sin(x) is the sinusoidal function; wherein the beamformer is a composite beam comprised of a plurality of disjoint beam lobes, and each of the plurality of disjoint beam lobes covers a desired angular interval. ### Claim 10 (depends on 9) The base station of claim 9, wherein the antenna elements are arranged in tandem in two parallel lines of a particular distance, and wherein the antenna elements in a line from among the two parallel lines are uniformly placed. ### Claim 11 (depends on 10) The base station of claim 10, wherein the antenna elements are dipole or cross-dipole or patch antennas. ### Claim 12 (depends on 10) The base station of claim 10, wherein the beamforming coefficients of tandem ones of the antenna elements have a same absolute value. ### Claim 13 (depends on 12) The base station of claim 12, wherein a difference in a phase of tandem ones of the antenna elements is set to achieve a desired isolation between a radiated signal in unwanted directions and intended directions. ### Claim 14 (depends on 9) The base station of claim 9, wherein the beamforming codebook is a hierarchical codebook comprising: a first layer codebook which is comprised of plurality of beamforming codewords for a given set of beams; and a second layer codebook which is comprised of plurality of index sets, wherein an index set denotes a composition of a composite codebook in terms of its constituent beams. ### Claim 15 (depends on 9) The base station of claim 9, wherein an absolute value of beamforming coefficients of a beamforming codeword is constant. ### Claim 16 (depends on 9) The base station of claim 9, wherein a codeword of the beamforming codebook can be decomposed as a linear summation of a particular number of phase vectors, wherein a phase vector is a vector for which an absolute value of the elements of the vector is constant.