# US 11,444,677 B2 · Communication devices for efficient beam management > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,677 B2 - Document ID: US11444677B2 - Status: Granted - Kind: B2 - Application number: 17/038,627 - Filed: 2020-09-30 - Published: 2021-01-14 - Granted: 2022-09-13 - Earliest claimed: 2018-04-05 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Chaitanya Tumula; Neng Wang; Bengt Lindoff - Web page: https://patentgrep.com/patent/US11444677B2 ## CPC - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/028: {Spatial transmit diversity using a single antenna at the transmitter} - H04B 7/088: {using beam selection} - H04B: TRANSMISSION ## Abstract A first communication device receives a first signal, the first signal being transmitted by a second communication device using a first spatial-domain transmit filter; determines, based on the first signal, a Line-of-Sight characteristic associated with the first spatial-domain transmit filter, and transmits a first control message to the second communication device, the first control message indicating the Line-of-Sight characteristic associated with the first spatial-domain transmit filter. ## Claims ### Claim 1 A first communication device, comprising: a processor; and a non-transitory computer-readable storage medium coupled to the processor and storing a program executable by the processor, the program including instructions to: receive a first signal, the first signal being transmitted by a second communication device using a first spatial-domain transmit filter; determine, based on the first signal, a Line-of-Sight characteristic associated with the first spatial-domain transmit filter, wherein the Line-of-Sight characteristic indicates whether a propagation channel associated with a transmit beam resulting from the first spatial-domain transmit filter corresponds to a Line-of-Sight path or a non-Line-of-Sight path between the second communication device and the first communication device, and different spatial-domain transmit filters correspond to the Line-of-Sight path and the non-Line-of-Sight path; and transmit a first control message to the second communication device, the first control message indicating the Line-of-Sight characteristic associated with the first spatial-domain transmit filter. ### Claim 2 (depends on 1) The first communication device according to claim 1, wherein the program further includes instructions to: obtain location information associated with the second communication device; and select a first spatial-domain receive filter based on the obtained location information associated with the second communication device; and wherein the instructions to receive the first signal comprise instructions to receive the first signal using the first spatial-domain receive filter. ### Claim 3 (depends on 1) The first communication device according to claim 1, wherein the instructions to transmit the first control message to the second communication device comprise instructions to: transmit the first control message in response to the Line-of-Sight characteristic associated with the first spatial-domain transmit filter corresponding to the Line-of-Sight path. ### Claim 4 (depends on 1) The first communication device according to claim 1, wherein the instructions to receive the first signal comprise instructions to: receive the first signal using a first spatial-domain receive filter; and wherein the program further includes instructions to: select a second spatial-domain receive filter based on the determined Line-of-Sight characteristic associated with the first spatial-domain transmit filter; and receive a second signal from the second communication device using the selected second spatial-domain receive filter. ### Claim 5 (depends on 4) The first communication device according to claim 4, wherein the instructions to select the second spatial-domain receive filter comprise instructions to: select the second spatial-domain receive filter to cause a second receive beam to have a narrower beamwidth than a beamwidth of a first receive beam caused by the first spatial-domain receive filter, when the determined Line-of-Sight characteristic associated with the first spatial-domain transmit filter corresponds to the Line-of-Sight path; and select the second spatial-domain receive filter to cause the second receive beam to have a wider beamwidth than the beamwidth of a first receive beam caused by the first spatial-domain receive filter, when the determined Line-of-Sight characteristic associated with the first spatial-domain transmit filter corresponds to the non-Line-of-Sight path. ### Claim 6 (depends on 5) The first communication device according to claim 5, wherein the program further includes instructions to: in response to the second receive beam having the narrower beamwidth than the first receive beam, select the second spatial-domain receive filter to cause the resulting second receive beam to be contained in the first receive beam. ### Claim 7 (depends on 1) The first communication device according to claim 1, wherein the instructions to determine the Line-of-Sight characteristic associated with the first spatial-domain transmit filter comprise instructions to: estimate a propagation channel between the first communication device and the second communication device based on the received first signal, to obtain a metric associated with the propagation channel; and determine the Line-of-Sight characteristic based on the obtained metric. ### Claim 8 (depends on 7) The first communication device according to claim 7, wherein the metric associated with the propagation channel is a root-mean-square delay spread, a frequency selectivity, or a Rician factor. ### Claim 9 (depends on 1) The first communication device according to claim 1, wherein the program further includes instructions to: estimate a propagation channel between the first communication device and the second communication device based on the first signal, to obtain channel state information; and transmit the channel state information in a channel state information report to the second communication device. ### Claim 10 (depends on 9) The first communication device according to claim 9, wherein the program further includes instructions to: transmit the channel state information report in the first control message. ### Claim 11 (depends on 9) The first communication device according to claim 9, wherein the program further includes instructions to: transmit the channel state information report in a second control message separate from the first control message. ### Claim 12 (depends on 9) The first communication device according to claim 9, wherein the channel state information is a channel quality indicator, a precoding matrix indicator, a channel state information reference signal resource index, a strongest layer indicator, a rank indicator, or an L1-reference signal received power associated with the first spatial-domain transmit filter. ### Claim 13 A second communication device, comprising: a processor; and a non-transitory computer-readable storage medium coupled to the processor and storing a program for execution by the processor, the program including instructions to: transmit a first signal using a first spatial-domain transmit filter to a first communication device; receive a first control message from the first communication device in response to the transmission of the first signal, wherein the first control message indicates a Line-of-Sight characteristic associated with the first spatial-domain transmit filter, wherein the Line-of-Sight characteristic indicates whether a propagation channel associated with a transmit beam resulting from the first spatial-domain transmit filter corresponds to a Line-of-Sight path or a non-Line-of-Sight path between the second communication device and the first communication device, and different spatial-domain transmit filters correspond to the Line-of-Sight path and the non-Line-of-Sight path; select a second spatial-domain transmit filter based on the indicated Line-of-Sight characteristic associated with the first spatial-domain transmit filter; and transmit a second signal to the first communication device using the selected second spatial-domain transmit filter. ### Claim 14 (depends on 13) The second communication device according to claim 13, wherein the instructions to select the second spatial-domain transmit filter comprise instructions to: select the second spatial-domain transmit filter to cause a second transmit beam to have a narrower beamwidth than a beamwidth of a first transmit beam caused by the first spatial-domain transmit filter, when the determined Line-of-Sight characteristic associated with the first spatial-domain transmit filter corresponds to the Line-of-Sight path; and select the second spatial-domain transmit filter to cause the second transmit beam to have a wider beamwidth than a beamwidth of a first transmit beam caused by the first spatial-domain transmit filter, when the determined Line-of-Sight characteristic associated with the first spatial-domain transmit filter corresponds to the non-Line-of-Sight path. ### Claim 15 (depends on 13) The second communication device according to claim 13, wherein the program includes instructions to: receive, from the first communication device in the first control message, a channel state information report comprising channel state information associated with the first spatial-domain transmit filter; and select the second spatial-domain transmit filter based on the Line-of-Sight characteristic associated with the first spatial-domain transmit filter and the channel state information associated with the first spatial-domain transmit filter. ### Claim 16 A method, comprising: receiving, by a first communications device from a second communication device, a first signal transmitted using a first spatial-domain transmit filter; determining, by the first communications device based on the first signal, a Line-of-Sight characteristic associated with the first spatial-domain transmit filter, wherein the Line-of-Sight characteristic indicates whether a propagation channel associated with a transmit beam resulting from the first spatial-domain transmit filter corresponds to a Line-of-Sight path or a non-Line-of-Sight path between the second communication device and the first communication device, and different spatial-domain transmit filters correspond to the Line-of-Sight path and the non-Line-of-Sight path; and transmitting, by the first communications device, a first control message to the second communication device, the first control message indicating the Line-of-Sight characteristic associated with the first spatial-domain transmit filter. ### Claim 17 (depends on 16) A computer program storing a program code executable by a computer, wherein when the computer executes the code, the first communications device is caused to for perform the method according to claim 16. ### Claim 18 A method, comprising: transmitting, by a second communication device to a first communication device, a first signal using a first spatial-domain transmit filter; receiving, by the second communication device, a first control message from the first communication device in response to the transmission of the first signal, wherein the first control message indicates a Line-of-Sight characteristic associated with the first spatial-domain transmit filter, wherein the Line-of-Sight characteristic indicates whether a propagation channel associated with a transmit beam resulting from the first spatial-domain transmit filter corresponds to a Line-of-Sight path or a non-Line-of-Sight path between the second communication device and the first communication device, and different spatial-domain transmit filters correspond to the Line-of-Sight path and the non-Line-of-Sight path; selecting a second spatial-domain transmit filter based on the indicated Line-of-Sight characteristic associated with the first spatial-domain transmit filter; and transmitting a second signal to the first communication device using the selected second spatial-domain transmit filter. ### Claim 19 (depends on 18) A computer program storing a program code executable by a computer, wherein when the computer executes the code, the second communications device is caused to perform the method according to claim 18.