# US 11,452,002 B2 · Method whereby terminal transmits device-to-device (D2D) signal in wireless communication system that supports D2D communication, 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 11,452,002 B2 - Document ID: US11452002B2 - Status: Granted - Kind: B2 - Application number: 16/648,063 - Filed: 2018-09-19 - Published: 2020-07-09 - Granted: 2022-09-20 - Earliest claimed: 2017-09-19 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Hyukjin Chae; Seungmin Lee - Web page: https://patentgrep.com/patent/US11452002B2 ## CPC - H04W 28/0289: {Congestion control (load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12)} - H04W 76/14: Direct-mode setup - H04W 72/52: based on load - 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) ## Abstract Disclosed are a method whereby a terminal transmits a device-to-device (D2D) signal in a wireless communication system that supports D2D communication according to various embodiments, and an apparatus therefor. Disclosed are a method whereby a terminal transmits a D2D signal, and an apparatus therefor, wherein the method comprises: a step of measuring a technology congestion level with regard to a predetermined resource area; and a step of determining a wireless technology that is to be used for the 2D2 signal transmission on the basis of the technology congestion level, and transmitting the D2D signal on the basis of the determined wireless technology, and wherein the technology congestion level is related to the proportion of received signals that include information regarding the usage of a particular wireless technology in the predetermined resource area. ## Claims ### Claim 1 A method of transmitting a sidelink signal by a user equipment (UE) in a wireless communication system supporting sidelink communication, the method comprising: configuring a resource pool for the sidelink signal; receiving a plurality of Physical Sidelink Control Channels (PSCCHs) in the resource pool for a predetermined period; measuring a congestion level based on the received plurality of PSCCHs; selecting transmission resources for a transmission of the sidelink signal within the resource pool; and transmitting the sidelink signal in the transmission resources based on the congestion level, wherein the congestion level is a ratio of PSCCHs to which a transmit diversity (TxD) transmission scheme is applied among the plurality of PSCCHs, and wherein the sidelink signal is transmitted by applying the TxD transmission scheme based on the ratio of PSCCHs to which the TxD transmission scheme greater than a predetermined threshold. ### Claim 2 (depends on 1) The method of claim 1, the sidelink signal is transmitted without applying the TxD transmission scheme based on the congestion level less than a predetermined threshold. ### Claim 3 (depends on 1) The method of claim 1, wherein whether the TxD transmission scheme is applied to the PSCCHs is determined based on properties of the PSCCHs. ### Claim 4 (depends on 3) The method of claim 3, wherein the properties of the PSCCHs includes at least one of a cyclic prefix (CP) length, a sequence, and a demodulation reference signal (DMRS) allocated for the signal. ### Claim 5 (depends on 1) The method of claim 1, wherein the PSCCHs include information on whether the TxD is applied. ### Claim 6 (depends on 1) The method of claim 1, wherein the ratio of the PSCCHs to which the TxD transmission scheme is applied is determined based on information on a priority level included in the corresponding PSCCHs. ### Claim 7 (depends on 1) The method of claim 1, wherein the signal is a control signal that includes information related to the application of the TxD. ### Claim 8 (depends on 1) The method of claim 1, wherein the signal related to the specific radio technology is a signal having received strength greater than or equal to a predetermined signal strength. ### Claim 9 A user equipment (UE) for transmitting a sidelink signal in a wireless communication system supporting sidelink communication, the UE comprising: a transceiver; and a processor configured to: configure a resource pool for the sidelink signal; receive a plurality of Physical Sidelink Control Channels (PSCCHs) in the resource pool for a predetermined period; measure a congestion level based on the received plurality of PSCCHs; select transmission resources for a transmission of the sidelink signal within the resource pool; and transmit the sidelink signal in the transmission resources based on the congestion level, wherein the congestion level is a ratio of PSCCHs to which a transmit diversity (TxD) transmission scheme is applied among the plurality of PSCCHs, and wherein the sidelink signal is transmitted by applying the TxD transmission scheme based on the ratio of PSCCHs to which the TxD transmission scheme greater than a predetermined threshold.