Sidelink control information (sci) in new radio (nr) unlicensed

Abstract

A user equipment (UE), including a vehicle to everything (V2X) device, a baseband processor or other network device can operate in an unlicensed network to acquire a channel occupancy time (COT) for sidelink (SL) transmission and provide sidelink control information (SCI) with a first stage SCI in a physical sidelink control channel (PSCCH) and a second stage SCI in a physical sidelink shared channel (PSSCH). The first stage SCI or the second stage SCI can provide COT indications to a receiving UE device that enable COT sharing in a sidelink unlicensed COT (SL-U COT) for SL communication.

What is claimed is: 
     
         1 . A User Equipment (UE) comprising:
 a memory;   processing circuitry, coupled to the memory, configured to, when executing instructions stored in the memory, cause the UE to:
 generate sidelink (SL) control information (SCI), wherein the SCI comprises a first stage SCI and a second stage SCI, and wherein at least one of: the first stage SCI or the second stage SCI comprises one or more channel occupancy time (COT) indications that enable sharing of an SL unlicensed (SL-U) COT of an SL transmission; and 
 transmit the first stage SCI on a physical shared control channel (PSCCH) and the second stage SCI on a physical sidelink shared channel (PSSCH) in the SL transmission. 
   
     
     
         2 . The UE of  claim 1 , wherein the second stage SCI comprises multiple slots of the PSSCH with different Hybrid Automatic Repeat Request (HARQ) process Identifiers (HARQ IDs) corresponding to the multiple slots, respectively, or a same HARQ process ID for each slot. 
     
     
         3 . The UE of  claim 1 , wherein the processing circuitry is further configured to:
 perform a category (CAT) 4 clear channel assessment (CCA) operation to acquire access to an SL channel based on a channel access priority, and   wherein the one or more COT indications comprise a channel access priority indication of the channel access priority used to access the SL channel by the CAT 4 CCA operation.   
     
     
         4 . The UE of  claim 3 , wherein the channel access priority indication enables sharing of the SL-U COT with a same priority as the channel access priority or a higher priority than the channel access priority based on a downlink (DL) channel access priority class (CAPC) or an uplink (UL) CAPC. 
     
     
         5 . The UE of  claim 1 , wherein the one or more COT indications comprise at least one of: an energy detection threshold (EDT) or a transmission power to be used by a receiving device for sharing of the SL-U COT of the SL transmission. 
     
     
         6 . The UE of  claim 5 , wherein the processing circuitry is further configured to:
 determine the EDT based on a power of a sensing operation performed on an SL channel, wherein the EDT and the transmission power of the one or more COT indications indicate the power to be used by a receiving device for sensing and transmitting, respectively, on the SL channel in response to sharing the SL-U COT; or   receive the EDT in a UE specific parameter of a radio resource control (RRC) signaling.   
     
     
         7 . The UE of  claim 1 , wherein the one or more COT indications comprise a COT duration indication that indicates at least one of: a total COT duration based on a priority class of a channel access priority indication, a maximum COT (MCOT), a multiple transmission time interval (Multi-TTI) SL PSSCH COT duration, or a remaining COT length for a receiving V2X device. 
     
     
         8 . The UE of  claim 1 , wherein the one or more COT indications comprise a clear channel assessment (CCA) type and a cyclic prefix (CP) extension, based on a number of bits comprising up to six bits. 
     
     
         9 . The UE of  claim 1 , wherein the one or more COT indications comprise a PSSCH frequency domain resource allocation that indicates an interlace used for the SL transmission based on one or more bit fields or a bitmap. 
     
     
         10 . A method comprising:
 receiving, via processing circuitry, sidelink (SL) control information (SCI) in a new radio (NR) unlicensed network, wherein the SCI comprises a first stage SCI on a physical shared control channel (PSCCH) and a second stage SCI on a physical sidelink shared channel (PSSCH), wherein at least one of: the first stage SCI or the second stage SCI comprises one or more channel occupancy time (COT) indications that enable a sharing of an SL unlicensed (SL-U) COT that is previously acquired on an SL channel; and   transmitting an SL transmission on the SL-U COT based on the one or more COT indications.   
     
     
         11 . The method of  claim 10 , wherein the processing circuitry is further configured to:
 performing a clear channel assessment (CCA) on the SL channel based on a channel access priority indication of the one or more COT indications, wherein the CCA is shorter than a category (CAT) 4 CCA, and the SL transmission is based on traffic that is equal to or lower in priority than a downlink (DL) channel access priority class (CAPC) or an uplink (UL) CAPC of the channel access priority indication.   
     
     
         12 . The method of  claim 10 , wherein the processing circuitry is further configured to:
 receiving at least one of: an energy detection threshold (EDT) or a transmission power to be used for the SL transmission from the one or more COT indications, a unicast signaling, or a groupcast signaling; and   generating the SL transmission based on the at least one of: the EDT or the transmission power, wherein the EDT is inversely proportion to the transmission power.   
     
     
         13 . The method of  claim 10 , wherein the one or more COT indications comprise a COT duration indication that indicates at least one of: a total COT duration, a maximum COT (MCOT), a multiple transmission time interval (Multi-TTI) SL PSSCH COT duration, or a remaining COT length, wherein the total COT duration is based on a priority class of a channel access priority used by an initiating vehicle-to-everything (V2X) device that previously acquired the SL channel, and the remaining COT length is based on the MCOT minus an initiating device transmission COT duration. 
     
     
         14 . The method of  claim 10 , wherein the one or more COT indications comprise one or more indications of at least one of: a clear channel assessment (CCA) type, a cyclic prefix (CP) extension, or a PSSCH frequency domain resource allocation that indicates an interlace used for the SL transmission. 
     
     
         15 . The method of  claim 10 , wherein the PSSCH comprises a plurality of slots with the second stage SCI being repeated in one or more slots of the plurality of slots, wherein the one or more slots comprise a same Hybrid Automatic Repeat Request (HARQ) process Identifiers (HARQ ID) or different HARQ process IDs, respectively, and wherein the second stage SCI is in every X slot of the plurality of slots, wherein X is a periodicity integer indicated by the first stage SCI. 
     
     
         16 . A baseband processor configured to cause a user equipment (UE) to:
 generate sidelink (SL) control information (SCI), wherein the SCI comprises a first stage SCI and a second stage SCI, and wherein at least one of: the first stage SCI or the second stage SCI comprises one or more channel occupancy time (COT) indications that enable sharing of an SL unlicensed (SL-U) COT of an SL transmission; and   provide the first stage SCI on a physical shared control channel (PSCCH) and the second stage SCI on a physical sidelink shared channel (PSSCH) in the SL transmission.   
     
     
         17 . The baseband processor of  claim 16 , wherein the one or more COT indications comprise at least one of: a channel access priority indication, a power indication, a COT duration, a clear channel assessment (CCA) type, a cyclic prefix (CP) extension, a PSSCH frequency domain resource allocation, or a periodicity X indication that indicates one or more slots of the PSSCH. 
     
     
         18 . The baseband processor of  claim 16 , further configured to cause the UE to:
 determine an energy detection threshold (EDT) based on a sensing operation performed of an SL channel and a transmission power, based on a non-vehicle-to-everything (V2X) device parameter or based on a path loss of a sidelink paired device during a device-to-device (D2D) discovery operation; and   provide at least one of: the EDT or the transmission power according to a decibel level as a power indication in the one or more COT indications.   
     
     
         19 . The baseband processor of  claim 16 , further configured to cause the UE to:
 receive an energy detection threshold (EDT) in a radio resource control (RRC) signaling in a UE specific parameter, a unicast for sidelink pairs, or a groupcast for a sidelink group; and   in response to receiving the EDT in the UE specific parameter, provide the EDT in the one or more COT indications.   
     
     
         20 . The baseband processor of  claim 16 , further configured to cause the UE to:
 transmit the second stage SCI in a first slot, each slot, or a periodicity of slots of the PSSCH, with a same HARQ process ID or different HARQ process IDs for each slot.