# US 12,224,958 B2 · Method and apparatus for transmitting and receiving reference signal for sidelink communication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,958 B2 - Document ID: US12224958B2 - Status: Granted - Kind: B2 - Application number: 17/276,651 - Filed: 2020-12-24 - Published: 2023-03-02 - Granted: 2025-02-11 - Earliest claimed: 2020-01-08 - Assignees: Hyundai Motor Company; Kia Motors Corporation; Wonkwang University Center for Industry-Academy Cooperation - Applicants: Hyundai Motor Company; Kia Motors Corporation; Wonkwang University Center For Industry-Academy Cooperation - Inventors: Gene Back Hahn; In Yong Jung; Hyuk Min Son - Web page: https://patentgrep.com/patent/US12224958B2 ## CPC - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04L 25/03866: {using scrambling} - H04L 27/2613: {Structure of the reference signals} - H04L 25/0224: {using sounding signals} - H04W 92/18: between terminal devices - 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 and an apparatus for transmitting and receiving reference signals for sidelink communication are provided. The operation method of a first terminal includes receiving a message including a first DMRS scrambling identifier for sidelink communication from a base station and calculating a first DMRS sequence based on the first DMRS scrambling identifier. Additionally, the method includes transmitting SCI and a first DMRS generated based on the first DMRS sequence to a second terminal. ## Claims ### Claim 1 An operation method of a first terminal in a communication system, the operation method comprising: receiving a message including a first demodulation reference signal (DMRS) scrambling identifier NID for sidelink communication from a base station; calculating a first pseudo-random sequence cinit by inputting the first DMRS scrambling identifier NID into Equation 1; cinit=(217(Nsymbslotns,fμ+l+1)(2NID+1)+2NID) mod 231 (Equation 1) calculating a first DMRS sequence rl(m) by inputting the first pseudo-random sequence cinit into Equation 2; and r l ( m ) = 1 2 ⁢ ( 1 - 2 ⁢ c ⁡ ( 2 ⁢ m ) ) + j ⁢ 1 2 ⁢ ( 1 - 2 ⁢ c ⁡ ( 2 ⁢ m + 1 ) ) ( Equation ⁢ 2 ) transmitting sidelink control information (SCI) and a first DMRS generated based on the first DMRS sequence rl(m) to a second terminal through a physical sidelink control channel (PSCCH), wherein Nsymbslot denotes a number of symbols in a slot, ns,fμ denotes a slot number in a frame, and l denotes a symbol number in the slot. ### Claim 2 (depends on 1) The operation method according to claim 1, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used to generate the first DMRS sequence, and the second DMRS scrambling identifier is used to generate a second DMRS sequence. ### Claim 3 (depends on 2) The operation method according to claim 2, wherein an order of the DMRS scrambling identifiers included in the identifier list is an order of using the DMRS scrambling identifiers. ### Claim 4 (depends on 1) The operation method according to claim 1, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used when a resource allocation (RA) scheme #1 is used for the sidelink communication, and the second DMRS scrambling identifier is used when an RA scheme #2 is used for the sidelink communication. ### Claim 5 (depends on 1) The operation method according to claim 1, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier, a second DMRS scrambling identifier, and a third DMRS scrambling identifier, the first DMRS scrambling identifier is used when the sidelink communication is performed based on a cast type #1, the second DMRS scrambling identifier is used when the sidelink communication is performed based on a cast type #2, the third DMRS scrambling identifier is used when the sidelink communication is performed based on a cast type #3, and the case type #1, the cast type #2, and the cast type #3 are broadcast, groupcast, and unicast, respectively. ### Claim 6 (depends on 1) The operation method according to claim 1, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used when a resource pool #1 is used for the sidelink communication, and the second DMRS scrambling identifier is used when a resource pool #2 is used for the sidelink communication. ### Claim 7 (depends on 6) The operation method according to claim 6, wherein the message further includes information indicating a number of DMRS scrambling identifiers available for the resource pool #1 and information indicating a number of DMRS scrambling identifiers available for the resource pool #2. ### Claim 8 (depends on 6) The operation method according to claim 6, wherein the message further includes a first cyclic shift value configured for the resource pool #1 and a second cyclic shift value configured for the resource pool #2. ### Claim 9 (depends on 8) The operation method according to claim 8, wherein an additional DMRS sequence for the resource pool #1 is generated by applying the first cyclic shift value to the first DMRS sequence. ### Claim 10 An operation method of a second terminal in a communication system, the operation method comprising: receiving a message including a first demodulation reference signal (DMRS) scrambling identifier for sidelink communication from a base station; performing a monitoring operation on a physical sidelink control channel (PSCCH) to obtain sidelink control information (SCI) from the first terminal; comparing a sequence of a reference signal detected on the PSCCH with a first DMRS sequence rl(m) generated based on the first DMRS scrambling identifier; and in response to determining that the sequence of the reference signal is equal to the first DMRS sequence rl(m), performing a reception operation of the SCI on the PSCCH, wherein the DMRS sequence rl(m) is generated based on Equation 1; r l ( m ) = 1 2 ⁢ ( 1 - 2 ⁢ c ⁡ ( 2 ⁢ m ) ) + j ⁢ 1 2 ⁢ ( 1 - 2 ⁢ c ⁡ ( 2 ⁢ m + 1 ) ) ( Equation ⁢ 1 ) an initialization value cinit of c(·) in Equation 1 is generated based on Equation 2; and cinit=(217(Nsymbslotns,fμ+l+1)(2NID+1)+2NID) mod 231 (Equation 2) NID denotes the first DMRS scrambling identifier, Nsymbslot denotes a number of symbols in a slot, ns,fμ denotes a slot number in a frame, and l denotes a symbol number in the slot. ### Claim 11 (depends on 10) The operation method according to claim 10, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used to generate the first DMRS sequence, and the second DMRS scrambling identifier is used to generate a second DMRS sequence. ### Claim 12 (depends on 10) The operation method according to claim 10, wherein in response to determining that first DMRS scrambling identifier is configured for a resource allocation (RA) scheme #1 among the RA scheme #1 and an RA scheme #2, and the first DMRS sequence rl(m) generated based on the first DMRS scrambling identifier is equal to the sequence of the reference signal, the RA scheme #1 is determined to be used for the sidelink communication. ### Claim 13 (depends on 10) The operation method according to claim 10, wherein in response to determining that first DMRS scrambling identifier is configured for a cast type #1 among the cast type #1, a cast type #2, and a cast type #3, and the first DMRS sequence rl(m) generated based on the first DMRS scrambling identifier is equal to the sequence of the reference signal, the sidelink communication is determined to be performed based on the cast type #1, and the case type #1, the cast type #2, and the cast type #3 are broadcast, groupcast, and unicast, respectively. ### Claim 14 (depends on 10) The operation method according to claim 10, wherein in response to determining that first DMRS scrambling identifier is configured for a resource pool #1 among the resource pool #1 and a resource pool #2, and the first DMRS sequence rl(m) generated based on the first DMRS scrambling identifier is equal to the sequence of the reference signal, the sidelink communication is determined to be performed using the resource pool #1. ### Claim 15 (depends on 14) The operation method according to claim 14, wherein the message further includes information indicating a number of DMRS scrambling identifiers available for the resource pool #1 and information indicating a number of DMRS scrambling identifiers available for the resource pool #2. ### Claim 16 A first terminal in a communication system comprising: a processor; and a memory storing at least one instruction executable by the processor, wherein the at least one instruction causes the first terminal to: receive a message including a first demodulation reference signal (DMRS) scrambling identifier NID for sidelink communication from a base station; calculate a first pseudo-random sequence cinit by inputting the first DMRS scrambling identifier NID into Equation 1; cinit=(217(Nsymbslotns,fμ+l+1)(2NID+1)+2NID) mod 231 (Equation 1) calculate a first DMRS sequence rl(m) by inputting the first pseudo-random sequence cinit into Equation 2; and r l ( m ) = 1 2 ⁢ ( 1 - 2 ⁢ c ⁡ ( 2 ⁢ m ) ) + j ⁢ 1 2 ⁢ ( 1 - 2 ⁢ c ⁡ ( 2 ⁢ m + 1 ) ) ( Equation ⁢ 2 ) transmit sidelink control information (SCI) and a first DMRS generated based on the first DMRS sequence rl(m) to a second terminal through a physical sidelink control channel (PSCCH), wherein Nsymbslot denotes a number of symbols in a slot, ns,fμ denotes a slot number in a frame, and l denotes a symbol number in the slot. ### Claim 17 (depends on 16) The first terminal according to claim 16, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used to generate the first DMRS sequence, and the second DMRS scrambling identifier is used to generate a second DMRS sequence. ### Claim 18 (depends on 16) The first terminal according to claim 16, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used when a resource allocation (RA) scheme #1 is used for the sidelink communication, and the second DMRS scrambling identifier is used when an RA scheme #2 is used for the sidelink communication. ### Claim 19 (depends on 16) The first terminal according to claim 16, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier, a second DMRS scrambling identifier, and a third DMRS scrambling identifier, the first DMRS scrambling identifier is used when the sidelink communication is performed based on a cast type #1, the second DMRS scrambling identifier is used when the sidelink communication is performed based on a cast type #2, the third DMRS scrambling identifier is used when the sidelink communication is performed based on a cast type #3, and the case type #1, the cast type #2, and the cast type #3 are broadcast, groupcast, and unicast, respectively. ### Claim 20 (depends on 16) The first terminal according to claim 16, wherein the message includes an identifier list, the identifier list includes the first DMRS scrambling identifier and a second DMRS scrambling identifier, the first DMRS scrambling identifier is used when a resource pool #1 is used for the sidelink communication, and the second DMRS scrambling identifier is used when a resource pool #2 is used for the sidelink communication.