# US 11,121,799 B2 · Method for determining modulation and coding scheme in wireless communication system, and device therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,799 B2 - Document ID: US11121799B2 - Status: Granted - Kind: B2 - Application number: 16/483,711 - Filed: 2017-07-26 - Published: 2020-01-23 - Granted: 2021-09-14 - Earliest claimed: 2017-02-05 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Minki Ahn; Jiwon Kang; Jonghyun Park - Web page: https://patentgrep.com/patent/US11121799B2 ## CPC - H04L 1/0003: {by switching between different modulation schemes} - H04L 1/0005: {applied to payload information} - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0695: {using beam selection} - H04B 7/088: {using beam selection} - H04L 1/00: Arrangements for detecting or preventing errors in the information received {(correcting synchronisation H04L7/00)} - H04L 1/0026: {Transmission of channel quality indication} - H04L 1/0027: {Scheduling of signalling, e.g. occurrence thereof} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W 72/12: Wireless traffic scheduling - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present invention provides a method for determining a modulation and coding scheme (MCS) to be applied to data in a wireless communication system, and a device therefor. Specifically, the method may comprise the steps of: reporting, to a base station, channel state information including a first measurement value related to a channel state between a terminal and the base station; receiving at least one downlink reference signal from the base station; calculating a second measurement value related to the channel state by using the received at least one downlink reference signal; when the second measurement values is equal to or smaller than a preconfigured threshold value in comparison with the first measurement value, transmitting, to the base station, a specific uplink signal requesting a change of an MCS designated to downlink data; and receiving the downlink data, to which the changed MCS has been applied, from the base station. ## Claims ### Claim 1 A method performed by a user equipment operating in a wireless communication system, the method comprising: reporting, to a base station, channel state information comprising a first measurement value related to a channel state between the user equipment and the base station; receiving, from the base station, at least one downlink reference signal; calculating a second measurement value related to the channel state using the received at least one downlink reference signal; transmitting, to the base station, a first scheduling request to request a change in a designated modulation and coding scheme (MCS) for downlink data based on the second measurement value being a preset threshold value or less compared to the first measurement value; and receiving, from the base station, the downlink data to which a changed MCS has been applied, wherein the first scheduling request is differentiated from a second scheduling request which is transmitted in an on-off state of energy for scheduling request of uplink data, and wherein the first scheduling request is used for at least one of (i) a beam-related uplink control information multiplexing request to feedback beam state information in an uplink data channel, (ii) a reference signal request for beam refinement, or (iii) a request for change in the designated MCS for the downlink data. ### Claim 2 (depends on 1) The method of claim 1, wherein the changed MCS is an MCS changed from the designated MCS based on a preset default value. ### Claim 3 (depends on 1) The method of claim 1, wherein the changed MCS is an MCS changed from the designated MCS based on a specific change value corresponding to a difference between the first measurement value and the second measurement value, among a plurality of preset change values. ### Claim 4 (depends on 3) The method of claim 3, wherein the first scheduling request comprises at least one of (i) information indicating the difference between the first measurement value and the second measurement value or (ii) information indicating the specific change value. ### Claim 5 (depends on 1) The method of claim 1, wherein the first scheduling request is generated based on a specific sequence corresponding to a request for which the first scheduling request is used. ### Claim 6 (depends on 1) The method of claim 1, wherein the first scheduling request comprises indication information configured with any one of 1 bit or 2 bits indicating for which request the first scheduling request is used. ### Claim 7 (depends on 1) The method of claim 1, further comprising: receiving, from the base station, at least one of indication information indicating whether the change of the designated MCS for the downlink data is permitted or configuration information for a triggering condition related to the request through higher layer signaling. ### Claim 8 A user equipment configured to operate in a wireless communication system, the user equipment comprising: a transceiver unit configured to transmit and receive radio signals, and a processor functionally connected to the transceiver unit, wherein the processor is configured to: report, to a base station, channel state information comprising a first measurement value related to a channel state between the user equipment and the base station; receive, from the base station, at least one downlink reference signal; calculate a second measurement value related to the channel state using the received at least one downlink reference signal; transmit, to the base station, a first scheduling request to request a change in a designated modulation and coding scheme (MCS) for downlink data based on the second measurement value being a preset threshold value or less compared to the first measurement value; and receive, from the base station, the downlink data to which a changed MCS has been applied, wherein the first scheduling request is differentiated from a second scheduling request which is transmitted in an on-off state of energy for scheduling request of uplink data, and wherein the first scheduling request is used for at least one of (i) a beam-related uplink control information multiplexing request to feedback beam state information in an uplink data channel, (ii) a reference signal request for beam refinement, or (iii) a request for change in the designated MCS for the downlink data. ### Claim 9 (depends on 8) The user equipment of claim 8, wherein the changed MCS is an MCS changed from the designated MCS based on a preset default value. ### Claim 10 (depends on 8) The user equipment of claim 8, wherein the changed MCS is an MCS changed from the designated MCS based on a specific change value corresponding to a difference between the first measurement value and the second measurement value, among a plurality of preset change values. ### Claim 11 A method performed by a base station operating in a wireless communication system, the method comprising: receiving, from a user equipment, channel state information comprising a first measurement value related to a change state between the user equipment and the base station; transmitting, to the user equipment, at least one downlink reference signal; receiving, from the user equipment, a first scheduling request to request a change in a designated modulation and coding scheme (MCS) for downlink data based on a second measurement value being a preset threshold value or less compared to the first measurement value, wherein the second measurement value is related to a channel state calculated by the user equipment using the at least one downlink reference signal; and transmitting, to the user equipment, the downlink data to which a changed MCS has been applied, in response to the first scheduling request, wherein the first scheduling request is differentiated from a second scheduling request which is transmitted in an on-off state of energy for scheduling request of uplink data, and wherein the first scheduling request is used for at least one of (i) a beam-related uplink control information multiplexing request to feedback beam state information in an uplink data channel, (ii) a reference signal request for beam refinement, or (iii) a request to change in the designated MCS for the downlink data. ### Claim 12 (depends on 11) The method of claim 11, wherein the changed MCS is an MCS changed from the designated MCS based on a preset default value. ### Claim 13 (depends on 11) The method of claim 11, wherein the changed MCS is an MCS changed from the designated MCS based on a specific change value corresponding to a difference between the first measurement value and the second measurement value, among a plurality of preset change values.