# US 11,444,671 B2 · Method for multicast transmission based on channel feedback > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,671 B2 - Document ID: US11444671B2 - Status: Granted - Kind: B2 - Application number: 16/747,956 - Filed: 2020-01-21 - Published: 2021-01-28 - Granted: 2022-09-13 - Earliest claimed: 2019-07-22 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Kwonyeol Park; Dongwoo Kim; Minho Shin; Changho Shin; Jonghun Rhee - Web page: https://patentgrep.com/patent/US11444671B2 ## CPC - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/063: {Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection} - H04L 1/0025: {Transmission of mode-switching indication} - H04L 1/0026: {Transmission of channel quality indication} - H04L 5/0057: {Physical resource allocation for CQI} - H04L 12/1845: {broadcast or multicast in a specific location, e.g. geocast (protocols for adapting network applications to user terminal location H04L67/52; services specially adapted for wireless communication networks making use of the location of users or terminals H04W4/02)} - H04L 12/189: {in combination with wireless systems (selective distribution or broadcast in wireless communication networks H04W4/06)} - H04W 4/06: Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services - H04W 52/16: Deriving transmission power values from another channel - H04W 52/228: {using past power values or information} - H04W 52/247: {where the output power of a terminal is based on a path parameter sent by another terminal} - H04L 2001/0093: {Point-to-multipoint} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method of receiving multicast transmission from a base station includes receiving allocation information about a feedback channel including a plurality of resources shared by another terminal, determining feedback information based on an estimated channel with the base station, determining a plurality of transmission power levels respectively corresponding to the plurality of resources based on the feedback information, and transmitting channel feedback to the base station on the feedback channel based on the plurality of transmission power levels. ## Claims ### Claim 1 A method performed by a terminal to receive multicast transmission from a base station, the method comprising: receiving allocation information associated with a feedback channel among a plurality of feedback channels allocated to respective ones of a plurality of multicast groups, the feedback channel including a plurality of resources shared between the terminal and another terminal; determining feedback information based on an estimated channel with the base station; determining, based on the feedback information, a plurality of transmission power levels corresponding to the plurality of resources shared with the another terminal, respectively; transmitting channel feedback to the base station on the feedback channel with transmission powers corresponding to the plurality of transmission power levels for the plurality of resources such that the base station simultaneously receives the channel feedback from the terminal and the another terminal; and receiving the multicast transmission from the base station in response to the channel feedback information transmitted thereto such that the channel feedback is utilized by the base station to determine a transmission parameter, and to provide the multicast transmission to the terminal and the another terminal based on the transmission parameter. ### Claim 2 (depends on 1) The method of claim 1, further comprising setting a magnitude of a first transmission power level to be inversely proportional to reception power from the base station, wherein the determining of the plurality of transmission power levels comprises setting respective ones of the plurality of transmission power levels as the first transmission power level or a second transmission power level based on the feedback information, the second transmission power level being lower than the first transmission power level. ### Claim 3 (depends on 2) The method of claim 2, wherein the setting the respective ones of the plurality of transmission power levels comprises: selecting one resource from among the plurality of resources based on the feedback information; setting a transmission power level of the selected one resource as the first transmission power level; and setting a transmission power level of unselected resources among the plurality of resources as the second transmission power level. ### Claim 4 (depends on 2) The method of claim 2, wherein the setting the respective ones of the plurality of transmission power levels comprises: selecting one resource from among the plurality of resources based on the feedback information; setting a transmission power level of the selected one resource as the second transmission power level; and setting a transmission power level of unselected resources among the plurality of resources as the first transmission power level. ### Claim 5 (depends on 2) The method of claim 2, wherein the setting the respective ones of the plurality of transmission power levels comprises: selecting at least one resource, which is successive in a frequency domain and/or a time domain, from among the plurality of resources based on the feedback information; setting a transmission power level of the selected at least one resource as the first transmission power level; and setting a transmission power level of each of unselected resources among the plurality of resources as the second transmission power level. ### Claim 6 (depends on 5) The method of claim 5, wherein the at least one resource includes a first resource of the plurality of resources. ### Claim 7 (depends on 5) The method of claim 5, wherein the at least one resource includes a last resource of the plurality of resources. ### Claim 8 A method performed by a terminal to provide a base station with channel feedback for multicast transmission, the method comprising: receiving allocation information associated with a feedback channel among a plurality of feedback channels allocated to respective ones of a plurality of multicast groups, the feedback channel including M resources shared between the terminal and another terminal, wherein M is an integer of more than 1; determining feedback information based on an estimated channel with the base station; encoding the feedback information as an M-bit string; setting, based on the M-bit string, each of M transmission power levels for the M resources as a first transmission power level or a second transmission power level; and transmitting channel feedback to the base station on the feedback channel with transmission powers corresponding to the M transmission power levels for the M resources such that the base station simultaneously receives the channel feedback from the terminal and the another terminal, the channel feedback being utilized by the base station to determine a transmission parameter, and to provide the multicast transmission to the terminal and the another terminal based on the transmission parameter. ### Claim 9 (depends on 8) The method of claim 8, wherein the encoding of the feedback information comprises: encoding the feedback information to the M-bit string using a one-hot encoding scheme or a one-cold encoding scheme. ### Claim 10 (depends on 8) The method of claim 8, wherein the encoding of the feedback information comprises: encoding the feedback information to the M-bit string based on a unary coding scheme. ### Claim 11 (depends on 8) The method of claim 8, wherein the determining of the feedback information includes determining a channel quality indicator (CQI) index, and the encoding of the feedback information includes encoding the CQI index as the M-bit string. ### Claim 12 (depends on 8) The method of claim 8, wherein the determining of the feedback information includes determining a modulation and coding scheme (MCS) index, and the encoding of the feedback information includes encoding the MCS index as the M-bit string. ### Claim 13 (depends on 8) The method of claim 8, further comprising extracting, from the allocation information, an encoding scheme performed on the feedback information, and the encoding of the feedback information includes encoding the feedback information as the M-bit string based on the encoding scheme. ### Claim 14 A method of providing multicast transmission to a plurality of terminals, the method comprising: allocating different ones of a plurality of feedback channels to respective ones of a plurality of multicast groups; providing the plurality of terminals with allocation information associated with a feedback channel among the plurality of feedback channels, the feedback channel including a plurality of resources shared with the plurality of terminals; simultaneously receiving, over the feedback channel, a plurality of channel feedbacks from the plurality of terminals; determining a transmission parameter based on a plurality of reception power accumulated in the plurality of resources using the plurality of channel feedbacks; and providing the multicast transmission to the plurality of terminals based on the transmission parameter. ### Claim 15 (depends on 14) The method of claim 14, wherein the determining of the transmission parameter comprises: determining a location of a resource corresponding to a lowest channel condition from among resources having a reception power level greater than or equal to a threshold value; and determining the transmission parameter based on the location of the resource. ### Claim 16 (depends on 14) The method of claim 14, wherein the determining of the transmission parameter comprises: determining a location of a resource corresponding to a lowest channel condition from among resources having a reception power level which is less than or equal to a threshold value; and determining the transmission parameter based on the location of the resource. ### Claim 17 (depends on 14) The method of claim 14, wherein the determining of the transmission parameter comprises: determining a location of a resource corresponding to a best channel condition from among resources having a reception power level which is greater than or equal to a threshold value; and determining the transmission parameter based on the location of the resource. ### Claim 18 (depends on 14) The method of claim 14, wherein the determining of the transmission parameter comprises: determining a location of a resource corresponding to a best channel condition from among resources having a reception power level which is less than or equal to a threshold value; and determining the transmission parameter based on the location of the resource. ### Claim 19 (depends on 14) The method of claim 14, wherein the determining of the transmission parameter comprises: determining a lowest channel condition from among a plurality of channel conditions corresponding to the plurality of channel feedbacks; and determining the transmission parameter based on the lowest channel condition.