# US 10,873,843 B2 · Method for transmitting/receiving D2D signal in wireless communication system and apparatus therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,843 B2 - Document ID: US10873843B2 - Status: Granted - Kind: B2 - Application number: 15/521,121 - Filed: 2015-10-21 - Published: 2017-11-23 - Granted: 2020-12-22 - Earliest claimed: 2014-10-21 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Seungmin Lee; Hanbyul Seo - Web page: https://patentgrep.com/patent/US10873843B2 ## CPC - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04W 56/001: {Synchronization between nodes} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 72/12: Wireless traffic scheduling - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 72/044: based on the type of the allocated resource - H04W 72/541: using the level of interference - H04W 84/12: WLAN [Wireless Local Area Networks] - H04W 92/18: between terminal devices - 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 The present invention relates to a method and an apparatus for receiving a device-to-device (D2D) signal by a first terminal having a single RX chain in a wireless communication system. Specifically, the present invention comprises the steps of: receiving a reference synchronization window value related to a first cell for wide area network (WAN) communication and a second cell for D2D communication; determining a first D2D signal search area by applying the reference synchronization window value to a discovery pool; and setting a particular gap for a first resource area which precedes, and is located adjacent to, the first D2D signal search area and for a second resource area which follows, and is located adjacent to, the first D2D signal search area, wherein the particular gap is a time interval set for allowing the single RX chain to cover a switching operation between the WAN communication and the D2D communication. ## Claims ### Claim 1 A method of receiving a device-to-device (D2D) signal by a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a base station, information for configuring at least one downlink subframe as a gap for the D2D signal; prioritizing, by the UE, reception of the D2D signal over a wide area network (WAN) downlink signal based on the D2D signal being overlapped with the WAN downlink signal on a downlink subframe and the downlink subframe being configured as the gap; and prioritizing, by the UE, reception of the WAN downlink signal over the D2D signal based on the D2D signal being overlapped with the WAN downlink signal on the downlink subframe and the downlink subframe not being configured as the gap. ### Claim 2 (depends on 1) The method according to claim 1, wherein the gap is configured to the at least one downlink subframe overlapping a D2D signal resource pool for receiving the D2D signal, and wherein the method further comprises switching between a downlink operation and a D2D operation. ### Claim 3 (depends on 1) The method according to claim 1, wherein the D2D signal is a discovery signal, a D2D Synchronization Signal (D2DSS), a D2D data signal, or a scheduling assignment signal. ### Claim 4 (depends on 1) The method according to claim 1, wherein the WAN downlink signal is a Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Cell specific Reference Signal (CRS), or Channel State Information-Reference Signal (CSI-RS). ### Claim 5 (depends on 1) The method according to claim 1, wherein the UE has limited reception capabilities. ### Claim 6 (depends on 1) The method according to claim 1, wherein based on the UE prioritizing reception of the D2D signal over the WAN downlink signal within the gap, the UE does not receive the WAN downlink signal, and wherein based on the UE prioritizing reception of the WAN downlink signal over the D2D signal outside the gap, the UE does not receive the D2D signal. ### Claim 7 An apparatus for receiving a device-to-device (D2D) signal by a user equipment (UE) in a wireless communication system, the apparatus comprising: a transceiver; and a processor coupled to the transceiver and configured to: control the transceiver to receive, from a base station, information for configuring at least one downlink subframe as a gap for the D2D signal, wherein the processor prioritizes reception of the D2D signal over a wide area network (WAN) downlink signal based on the D2D signal being overlapped with the WAN downlink signal on a downlink subframe and the downlink subframe being configured as the gap, and wherein the processor prioritizes reception of the WAN downlink signal over the D2D signal based on the D2D signal being overlapped with the WAN downlink signal on the downlink subframe and the downlink subframe not being configured as the gap. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the gap is configured to the at least one downlink subframe overlapping a D2D signal resource pool for receiving the D2D signal, and wherein the method further comprises switching between a downlink operation and a D2D operation. ### Claim 9 (depends on 7) The apparatus according to claim 7, wherein the D2D signal is a discovery signal, a D2D Synchronization Signal (D2DSS), a D2D data signal, or a scheduling assignment signal. ### Claim 10 (depends on 7) The apparatus according to claim 7, wherein the WAN downlink signal is a Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Cell specific Reference Signal (CRS), or Channel State Information-Reference Signal (CSI-RS). ### Claim 11 (depends on 7) The apparatus according to claim 7, wherein the UE has limited reception capabilities. ### Claim 12 (depends on 7) The apparatus according to claim 7, wherein based on the UE prioritizing reception of the D2D signal over the WAN downlink signal within the gap, the UE does not receive the WAN downlink signal, and wherein based on the UE prioritizing reception of the WAN downlink signal over the D2D signal outside the gap, the UE does not receive the D2D signal.