# US 12,119,901 B2 · Precoding vector based on singular value decomposition characterization of a communication channel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,901 B2 - Document ID: US12119901B2 - Status: Granted - Kind: B2 - Application number: 18/162,443 - Filed: 2023-01-31 - Published: 2024-08-01 - Granted: 2024-10-15 - Earliest claimed: 2023-01-31 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Jing Sun; Raviteja Patchava; Xiaoxia Zhang - Web page: https://patentgrep.com/patent/US12119901B2 ## CPC - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0617: {for beam forming} - H04B 7/22: Scatter propagation systems {, e.g. ionospheric, tropospheric or meteor scatter} - H04B: TRANSMISSION ## Abstract Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a network entity may obtain a singular value decomposition (SVD) precoding vector that is based at least in part on backscatter associated with a reference signal transmitted by the network entity. The network entity may apply the SVD precoding vector to an output signal. The network entity may transmit the output signal based at least in part on a set of antennas. Numerous other aspects are described. ## Claims ### Claim 1 An apparatus for wireless communication at a network entity, comprising: a memory; and one or more processors, coupled to the memory, configured to: obtain a singular value decomposition (SVD) precoding vector that is based at least in part on backscatter associated with a reference signal transmitted by the network entity; apply the SVD precoding vector to an output signal; and transmit the output signal based at least in part on a set of antennas. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the SVD precoder vector is based at least in part on a matched filter. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the matched filter comprises a uniform power matched filter configured to apply, for each antenna in the set of antennas, a commensurate amplitude level to a respective portion of the output signal transmitted by the antenna in the set of antennas. ### Claim 4 (depends on 2) The apparatus of claim 2, wherein the matched filter is configured to: apply, for each antenna in the set of antennas, a respective phase shift and a respective amplitude level to a respective portion of the output signal transmitted by the antenna in the set of antennas. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: transmit the reference signal based at least in part on the set of antennas. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the reference signal is a continuous wave. ### Claim 7 (depends on 5) The apparatus of claim 5, wherein the reference signal comprises a wideband transmission. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the wideband transmission comprises an orthogonal frequency division multiplexing (OFDM) waveform. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein the wideband transmission comprises two or more tones. ### Claim 10 (depends on 5) The apparatus of claim 5, wherein the one or more processors are further configured to: receive the backscatter based at least in part on transmission of the reference signal by the network entity, wherein the one or more processors, to obtain the SVD precoding vector, are configured to: generate the SVD precoding vector based at least in part on the backscatter. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the one or more processors are further configured to: compute a channel estimation matrix that is associated with a communication channel based at least in part on the backscatter, wherein, to generate the SVD precoder vector, the one or more processors are further configured to: generate the SVD precoding vector based at least in part on the channel estimation matrix. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the one or more processors, to generate the SVD precoding vector, are configured to: compute, based at least in part on the channel estimation matrix, a right eigenvector of an SVD representation of the communication channel. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein the one or more processors, to obtain the SVD precoding vector, are configured to: receive an indication of the SVD precoding vector via a backhaul link. ### Claim 14 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: receive user equipment (UE) capability information that is associated with a UE and specifies one or more supported frequency shifts; select a frequency shift from the one or more supported frequency shifts; and transmit an indication of the frequency shift. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the frequency shift is a first frequency shift, and wherein the one or more processors are further configured to: receive second UE capability information that is associated with a second UE and specifies a second set of one or more supported frequency shifts that are supported by the second UE; select a second frequency shift from the second set of one or more supported frequency shifts based at least in part on frequency division multiplexing the second frequency shift with the first frequency shift; and transmit a second indication of the second frequency shift. ### Claim 16 An apparatus for wireless communication at a network entity, comprising: a memory; and one or more processors, coupled to the memory, configured to: receive backscatter associated with a reference signal; and generate a singular value decomposition (SVD) precoding vector based at least in part on the backscatter. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the one or more processors are further configured to: transmit an indication of the SVD precoding vector. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the one or more processors, to transmit the indication of the SVD precoding vector, are configured to: transmit the indication of the SVD precoding vector via a backhaul link. ### Claim 19 (depends on 16) The apparatus of claim 16, wherein the SVD precoder vector is based at least in part on a matched filter. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the matched filter is based at least in part on the backscatter. ### Claim 21 (depends on 19) The apparatus of claim 19, wherein the matched filter comprises a uniform power matched filter that is configured to apply a commensurate amplitude level to a respective portion of an output signal transmitted by each antenna in a set of antennas. ### Claim 22 (depends on 19) The apparatus of claim 19, wherein the matched filter is configured to apply, for each antenna in a set of antennas, a respective phase shift and a respective amplitude level to a respective portion of an output signal transmitted by the antenna. ### Claim 23 (depends on 16) The apparatus of claim 16, wherein the reference signal is a continuous wave. ### Claim 24 (depends on 16) The apparatus of claim 16, wherein the reference signal comprises a wideband transmission. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the wideband transmission comprises an orthogonal frequency division multiplexing (OFDM) waveform. ### Claim 26 (depends on 24) The apparatus of claim 24, wherein the wideband transmission comprises two or more tones. ### Claim 27 (depends on 16) The apparatus of claim 16, wherein the one or more processors are further configured to: compute, based at least in part on the backscatter, a channel estimation matrix that is associated with a communication channel, wherein, to generate the SVD precoder vector, the one or more processors are further configured to: generate the SVD precoding vector based at least in part on the channel estimation matrix. ### Claim 28 (depends on 27) The apparatus of claim 27, wherein the one or more processors, to generate the SVD precoding vector, are configured to: compute a right eigenvector of an SVD representation of the communication channel based at least in part on the channel estimation matrix. ### Claim 29 A method of wireless communication performed by a network entity, comprising: obtaining a singular value decomposition (SVD) precoding vector that is based at least in part on backscatter associated with a reference signal transmitted by the network entity; applying the SVD precoding vector to an output signal; and transmitting the output signal based at least in part on a set of antennas. ### Claim 30 A method of wireless communication performed by a network entity, comprising: receiving backscatter associated with a reference signal; and generating a singular value decomposition (SVD) precoding vector based at least in part on the backscatter.