# US 12,184,416 B2 · Method and apparatus for performing sidelink retransmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,416 B2 - Document ID: US12184416B2 - Status: Granted - Kind: B2 - Application number: 17/626,071 - Filed: 2020-07-15 - Published: 2022-11-24 - Granted: 2024-12-31 - Earliest claimed: 2019-07-17 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Hanbyul Seo; Youngdae Lee; Robin Thomas - Web page: https://patentgrep.com/patent/US12184416B2 ## CPC - H04L 1/08: by repeating transmission, e.g. Verdan system {(H04L1/1858 and H04L1/189 take precedence)} - H04L 1/1825: Adaptation of specific ARQ protocol parameters according to transmission conditions - H04B 17/328: {Reference signal received power [RSRP]; Reference signal received quality [RSRQ]} - H04L 1/1657: {Implicit acknowledgement of correct or incorrect reception, e.g. with a moving window} - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L 1/189: {Transmission or retransmission of more than one copy of a message} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 2001/0093: {Point-to-multipoint} - H04W 4/40: for vehicles, e.g. vehicle-to-pedestrians [V2P] - H04W 28/0226: {based on location or mobility (handoff or reselection H04W36/00; mobile application services making use of the location of users or terminals H04W4/02)} - H04W 92/18: between terminal devices - 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 According to an embodiment of the present disclosure, a method for performing sidelink communication is provided. The method may include performing initial transmission to a second apparatus, performing at least one of first retransmission to the second apparatus, receiving HARQ NACK related to the initial transmission and the at least one of first retransmission from the second apparatus, and performing at least one of second retransmission to the second apparatus. ## Claims ### Claim 1 A method for performing wireless communication by a first apparatus, the method comprising: determining distance between the first apparatus and a second apparatus; performing an initial transmission to the second apparatus; performing at least one first retransmission related to the initial transmission to the second apparatus; receiving hybrid automatic repeat request negative acknowledgement (HARQ NACK) related to the initial transmission or the at least one of first retransmission from the second apparatus; and performing at least one second retransmission to the second apparatus based on the reception of the HARQ NACK, wherein a number of the at least one first retransmission and a number of the at least one second retransmission are determined based on mapping information between the distance and a number of retransmissions, and wherein the mapping information includes information related to the number of retransmissions mapped for each distance interval less than or equal to minimum communication range. ### Claim 2 (depends on 1) The method of claim 1, wherein a maximum number of the at least one first retransmission and a maximum number of the at least one second retransmission are determined based on the distance exceeding the minimum communication range. ### Claim 3 (depends on 1) The method of claim 1, wherein the number of retransmissions mapped for each distance interval is pre-configured in the first apparatus. ### Claim 4 (depends on 1) The method of claim 1, further including: determining at least one of reference signal received power (RSRP) for channel state information—reference signal (CSI-RS) or the RSRP for synchronization signal block (SSB), wherein the number of the at least one first retransmission and the number of the at least one second retransmission are determined based on (i) the at least one of the RSRP for the CSI-RS or the RSRP for the SSB, and (ii) the mapping information, and wherein the mapping information includes information related to a number of retransmissions mapped for each at least one of RSRP interval for CSI-RS or RSRP interval for SSB less than or equal to a threshold. ### Claim 5 (depends on 4) The method of claim 4, wherein a maximum number of the at least one first retransmission and a maximum number of the at least one second retransmission are determined based on the at least one of the RSRP for the CSI-RS or the RSRP for the SSB exceeding the threshold. ### Claim 6 (depends on 4) The method of claim 4, wherein the number of retransmissions mapped for each at least one of the RSRP intervals for the CSI-RS or the RSRP interval for the SSB is pre-configured in the first apparatus. ### Claim 7 (depends on 4) The method of claim 4, wherein based on the at least one of the RSRP for the CSI-RS or the RSRP for the SSB being unavailable, the number of the at least one first retransmission and the number of the at least one second retransmission are determined as a default number of retransmissions. ### Claim 8 (depends on 1) The method of claim 1, wherein based on the distance being unavailable, the number of the at least one first retransmission and the number of the at least one second retransmission are determined as a default number of retransmissions. ### Claim 9 A processing device adapted to control a first apparatus to perform wireless communication, the processing device comprising: at least one processor; and at least one memory connected to the at least one processor and storing instructions that, based on being executed, cause the at least one processor to perform operations comprising: determining distance between the first apparatus and a second apparatus; performing an initial transmission to the second apparatus; performing at least one first retransmission related to the initial transmission to the second apparatus; receiving hybrid automatic repeat request negative acknowledgement (HARQ NACK) related to the initial transmission or the at least one of first retransmission from the second apparatus; and performing at least one second retransmission to the second apparatus based on the reception of the HARQ NACK, wherein a number of the at least one first retransmission and a number of the at least one second retransmission are determined based on mapping information between the distance and a number of retransmissions, and wherein the mapping information includes information related to the number of retransmissions mapped for each distance interval less than or equal to minimum communication range. ### Claim 10 A first apparatus adapted to perform wireless communication, the first apparatus comprising: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions that, based on being executed, cause the at least one processor to perform operations comprising: determining distance between the first apparatus and a second apparatus; performing initial transmission to the second apparatus; performing at least one first retransmission related to the initial transmission to the second apparatus; receiving hybrid automatic repeat request negative acknowledgement (HARQ NACK) related to the initial transmission or the at least one of first retransmission from the second apparatus; and performing at least one second retransmission to the second apparatus based on the reception of the HARQ NACK, wherein a number of the at least one first retransmission and a number of the at least one second retransmission are determined based on mapping information between the distance and a number of retransmissions, and wherein the mapping information includes information related to the number of retransmissions mapped for each distance interval less than or equal to minimum communication range.