# US 11,121,899 B2 · Signal quality control method for basestations having multiple antennas > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,899 B2 - Document ID: US11121899B2 - Status: Granted - Kind: B2 - Application number: 16/658,380 - Filed: 2019-10-21 - Published: 2020-02-13 - Granted: 2021-09-14 - Earliest claimed: 2017-04-21 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Zhiqiang Zou; Honglin Chai - Web page: https://patentgrep.com/patent/US11121899B2 ## CPC - H04L 27/2623: {Reduction thereof by clipping} - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 27/2615: {Reduction thereof using coding} - H04L 5/0023: {Time-frequency-space} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract Embodiments relate to a signal quality control method and a base station. The method includes: determining, by the base station based on a clipping threshold corresponding to each of the plurality of antennas, a time-domain noise signal for clipping a first time-domain signal of each antenna; performing time-frequency transformation on the time-domain noise signal of each antenna to obtain a first frequency-domain noise signal; processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows; and using the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set. According to the embodiments, noise signals are processed jointly. ## Claims ### Claim 1 A signal quality control method, wherein the method is applied to a base station having a plurality of antennas, the base station uses the plurality of antennas to send a first time-domain signal set, so as to send L flows, the method comprising: determining, by the base station based on a clipping threshold corresponding to each of the plurality of antennas, a time-domain noise signal for clipping a first time-domain signal of each antenna; performing time-frequency transformation on the time-domain noise signal of each antenna to obtain a first frequency-domain noise signal; processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows; and clipping the first time-domain signal set using the second frequency-domain noise signal set and/or the third frequency-domain noise signal set. ### Claim 2 (depends on 1) The method according to claim 1, wherein the using of the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set comprises: weighting the second frequency-domain noise signal set based on a modulation scheme of each of the L flows and weighting the third frequency-domain noise signal set based on a weight of the complementary space of the L flows to obtain a fourth frequency-domain noise signal set; and performing time-frequency transformation on the first time-domain signal set to obtain a first frequency-domain signal set, and using the fourth frequency-domain noise signal set in frequency domain to clip the first frequency-domain signal set; or performing time-frequency transformation on the fourth frequency-domain noise signal set to obtain a fourth time-domain noise signal set, and using the fourth time-domain noise signal set in time domain to clip the first time-domain signal set. ### Claim 3 (depends on 1) The method according to claim 1, wherein the signal quality control method is performed after precoding and before generation of an orthogonal frequency division multiplexing (OFDM) signal, and the precoding comprises: dividing, by the base station, P terminals into p groups based on respective channel information reported by the P terminals or uplink measurement information, performing precoding weighting on L flows of each group of terminals independently, and obtaining, based on a precoding matrix corresponding to each group of terminals, the first frequency-domain signal set sent by the plurality of antennas. ### Claim 4 (depends on 3) The method according to claim 3, wherein before the determining, by the base station based on a clipping threshold corresponding to each antenna, of the time-domain noise signal for clipping a first time-domain signal of each antenna, the method further comprises: performing, by the base station, time-frequency transformation on the first frequency-domain signal set to obtain the first time-domain signal set sent by the plurality of antennas. ### Claim 5 (depends on 1) The method according to claim 1, wherein the signal quality control method is performed after precoding and generation of an orthogonal frequency division multiplexing (OFDM) signal, and the precoding comprises: dividing, by the base station, P terminals into p groups based on respective channel information reported by the P terminals or uplink measurement information, performing precoding weighting on L flows of each group of terminals independently, and obtaining, based on a precoding matrix corresponding to each group of terminals, the first frequency-domain signal set sent by the plurality of antennas. ### Claim 6 (depends on 2) The method according to claim 2, wherein the L flows are L flows processed using a precoding matrix; and the processing of the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows comprises: processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose, based on the precoding matrix, the first frequency-domain noise signals into the second frequency-domain noise signal set in the L flow directions and/or the third frequency-domain noise signal set in the complementary space of the L flows. ### Claim 7 A base station, the base station comprising a plurality of antennas to send a first time-domain signal set, so as to send L flows; and the base station further comprising a memory configured to store a communication instruction; and a processor configured to perform the following operations based on the communication instruction stored in the memory: determining, based on a clipping threshold corresponding to each of the plurality of antennas, a time-domain noise signal for clipping a first time-domain signal of each antenna; performing time-frequency transformation on the time-domain noise signal of each antenna to obtain a first frequency-domain noise signal; processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows; and using the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set. ### Claim 8 (depends on 7) The base station according to claim 7, wherein the processor performs the operation of using the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set, and the operation comprises: weighting the second frequency-domain noise signal set based on a modulation scheme of each of the L flows, and weighting the third frequency-domain noise signal set based on a weight of the complementary space of the L flows to obtain a fourth frequency-domain noise signal set; and performing time-frequency transformation on the first time-domain signal set to obtain a first frequency-domain signal set, and using the fourth frequency-domain noise signal set in frequency domain to clip the first frequency-domain signal set; or performing time-frequency transformation on the fourth frequency-domain noise signal set to obtain a fourth time-domain noise signal set, and using the fourth time-domain noise signal set in time domain to clip the first time-domain signal set. ### Claim 9 (depends on 7) The base station according to claim 7, wherein the processor is configured to perform the operation after precoding and before generation of an orthogonal frequency division multiplexing (OFDM) signal; and the precoding comprises: dividing, by the base station, P terminals into p groups based on respective channel information reported by the P terminals or uplink measurement information, performing precoding weighting on L flows of each group of terminals independently, and obtaining, based on a precoding matrix corresponding to each group of terminals, the first frequency-domain signal set sent by the plurality of antennas. ### Claim 10 (depends on 9) The base station according to claim 9, wherein the processor is further configured to: before performing the operation of determining, based on a clipping threshold corresponding to each antenna, of the time-domain noise signal for clipping a first time-domain signal of each antenna, perform the following operation according to a program instruction stored in the memory: performing time-frequency transformation on the first frequency-domain signal set to obtain the first time-domain signal set sent by the plurality of antennas. ### Claim 11 (depends on 7) The base station according to claim 7, wherein the processor is configured to perform the operation after precoding and generation of an orthogonal frequency division multiplexing (OFDM) signal; and the precoding comprises: dividing, by the base station, P terminals into p groups based on respective channel information reported by the P terminals or uplink measurement information, performing precoding weighting on L flows of each group of terminals independently, and obtaining, based on a precoding matrix corresponding to each group of terminals, the first frequency-domain signal set sent by the plurality of antennas. ### Claim 12 (depends on 8) The base station according to claim 8, wherein the L flows are L flows processed using a precoding matrix; and the processor processes the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows, the processing comprising: processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose, based on the precoding matrix, the first frequency-domain noise signals into the second frequency-domain noise signal set in the L flow directions and/or the third frequency-domain noise signal set in the complementary space of the L flows. ### Claim 13 A non-transitory computer readable storage medium for storing a program, wherein the program comprises an instruction, and when the instruction is executed by a base station, the base station is enabled to perform the method, comprising: determining, by the base station based on a clipping threshold corresponding to each of a plurality of antennas, a time-domain noise signal for clipping a first time-domain signal of each antenna; performing time-frequency transformation on the time-domain noise signal of each antenna to obtain a first frequency-domain noise signal; processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows; and using the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set. ### Claim 14 (depends on 13) The non-transitory computer readable storage medium according to claim 13, wherein the using of the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set comprises: weighting the second frequency-domain noise signal set based on a modulation scheme of each of the L flows, and weighting the third frequency-domain noise signal set based on a weight of the complementary space of the L flows, to obtain a fourth frequency-domain noise signal set; and performing time-frequency transformation on the first time-domain signal set to obtain a first frequency-domain signal set, and using the fourth frequency-domain noise signal set in frequency domain to clip the first frequency-domain signal set; or performing time-frequency transformation on the fourth frequency-domain noise signal set to obtain a fourth time-domain noise signal set, and using the fourth time-domain noise signal set in time domain to clip the first time-domain signal set. ### Claim 15 (depends on 13) The non-transitory computer readable storage medium according to claim 13, wherein the signal quality control method is performed after precoding and before generation of an orthogonal frequency division multiplexing (OFDM) signal, and the precoding comprises: dividing, by the base station, P terminals into p groups based on respective channel information reported by the P terminals or uplink measurement information, performing precoding weighting on L flows of each group of terminals independently, and obtaining, based on a precoding matrix corresponding to each group of terminals, the first frequency-domain signal set sent by the plurality of antennas. ### Claim 16 (depends on 15) The non-transitory computer readable storage medium according to claim 15, wherein before the determining, by the base station based on the clipping threshold corresponding to each antenna, a time-domain noise signal for clipping a first time-domain signal of each antenna, further comprising: performing, by the base station, time-frequency transformation on the first frequency-domain signal set to obtain the first time-domain signal set sent by the plurality of antennas. ### Claim 17 (depends on 13) The non-transitory computer readable storage medium according to claim 13, wherein the signal quality control method is performed after precoding and generation of an orthogonal frequency division multiplexing (OFDM) signal, and the precoding comprises: dividing, by the base station, P terminals into p groups based on respective channel information reported by the P terminals or uplink measurement information, performing precoding weighting on L flows of each group of terminals independently, and obtaining, based on a precoding matrix corresponding to each group of terminals, the first frequency-domain signal set sent by the plurality of antennas. ### Claim 18 (depends on 14) The non-transitory computer readable storage medium according to claim 14, wherein the L flows are L flows processed using a precoding matrix; and the processing of the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into the second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows comprises: processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose, based on the precoding matrix, the first frequency-domain noise signals into the second frequency-domain noise signal set in the L flow directions and/or the third frequency-domain noise signal set in the complementary space of the L flows.