# US 10,321,475 B2 · Method and apparatus for retransmitting scheduling assignment information in wireless communication system supporting device to device (D2D) communication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,321,475 B2 - Document ID: US10321475B2 - Status: Granted - Kind: B2 - Application number: 15/126,992 - Filed: 2015-04-14 - Published: 2018-02-01 - Granted: 2019-06-11 - Earliest claimed: 2014-04-14 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Youngtae Kim; Hanbyul Seo; Jihyun Lee; Seungmin Lee; Myoungseob Kim; Daewon Seo; Hyukjin Chae; Kijun Kim; Inkwon Seo - Web page: https://patentgrep.com/patent/US10321475B2 ## CPC - H04W 72/1263: Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows - H04L 1/1887: {Scheduling and prioritising arrangements} - H04W 72/20: Control channels or signalling for resource management - H04W 76/14: Direct-mode setup - H04W 72/02: Selection of wireless resources by user or terminal - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Disclosed is a method for retransmitting scheduling assignment (SA) information between half-duplex user equipment in a wireless communication system. The method for retransmitting SA information may comprise the steps of: receiving, through a first resource area, a D2D signal including first SA information transmitted by a second user equipment, and second SA information transmitted by a third user equipment; if the target user equipment of the second SA information is the second user equipment, determining whether to retransmit the second SA information for the second user equipment; and if it is determined to retransmit the second information, transmitting the second information through a second resource area. ## Claims ### Claim 1 A method for transmitting scheduling assignment (SA) information between half-duplex user equipments (UEs) in a wireless communication system, the method performed by a first UE and comprising: receiving a plurality of SA information for the first UE from a plurality of UEs; determining that SA information for transmission to a second UE and SA information transmitted from the second UE are included in the received plurality of SA information; determining that the second UE is in a same group with the first UE; and transmitting the SA information for transmission to the second UE to the second UE, wherein the first UE is a UE nearest the second UE among the plurality of UEs, and wherein the SA information is transmitted a number of times within a predetermined period, the number of times determined based on a measured power of the SA information transmitted from the second UE. ### Claim 2 (depends on 1) The method of claim 1, wherein the SA information for the second UE is further transmitted based on a predetermined probability. ### Claim 3 (depends on 1) The method of claim 1, wherein the SA information for the second UE is further transmitted when a value obtained by a modular operation for an identifier of the first UE and a value obtained by a modular operation for an identifier of the second UE are equal. ### Claim 4 (depends on 1) The method of claim 1, wherein each of the received plurality of SA information includes information for a target UE, resource information used for transmitting data to the target UE, and information for demodulating the data. ### Claim 5 (depends on 1) The method of claim 1, wherein the received plurality of SA information is broadcast. ### Claim 6 A method for transmitting scheduling assignment (SA) information between half-duplex user equipments (UE) in a wireless communication system, the method performed by a first UE and comprising: receiving a plurality of SA information for the first UE from a plurality of UEs; determining that SA information for transmission to a second UE and SA information transmitted from the second UE are included in the plurality of SA information; determining that the second UE is in a same group with the first UE; and transmitting an identifier (ID) of the second UE to a third UE from which the SA information for transmission to the second UE was received, wherein the first UE is a UE nearest the second UE among the plurality of UEs, and wherein the ID is transmitted a number of times within a predetermined period, the number of times determined based on a measured power of the SA information transmitted from the second UE. ### Claim 7 (depends on 6) The method of claim 6, further comprising receiving a re-transmission of the SA information for the second UE from the third UE after transmitting the ID of the second UE. ### Claim 8 (depends on 6) The method of claim 6, wherein each of the received plurality of SA information includes information for a target UE, resource information used for transmitting data to the target UE, and information for demodulating the data. ### Claim 9 (depends on 6) The method of claim 6, wherein the received plurality of SA information is broadcast. ### Claim 10 A first user equipment (UE) for supporting transmission of scheduling assignment (SA) information between half-duplex UEs in a wireless communication system, the first UE comprising: a radio frequency unit configured to transmit and receive signals; and a processor is configured to: control the RF unit to receive a plurality of SA information for the first UE from a plurality of UEs; determine that SA information for transmission to a second UE and SA information transmitted from the second UE are included in the received plurality of SA information; determine that the second UE is in a same group with the first UE; and control the RF unit to transmit the SA information for transmission to the second UE to the second UE, wherein the first UE is a UE nearest the second UE among the plurality of UEs, and wherein the SA information is transmitted a number of times within a predetermined period, the number of times determined based on a measured power of the SA information transmitted from the second UE. ### Claim 11 (depends on 10) The first UE of claim 10, wherein the SA information for the second UE is further transmitted based on a predetermined probability. ### Claim 12 (depends on 10) The first UE of claim 10, wherein the SA information for the second UE is further transmitted when a value obtained by a modular operation for an identifier of the first UE and a value obtained by a modular operation for an identifier of the second UE are equal. ### Claim 13 (depends on 10) The first UE of claim 10, wherein each of the received plurality of SA information includes information for a target UE, resource information used for transmitting data to the target UE, and information for demodulating the data. ### Claim 14 (depends on 10) The first UE of claim 10, wherein the received plurality of SA information is broadcast.