Sidelink control information processing
Embodiments are presented herein of apparatuses, systems, and methods for a vehicle-to-everything (V2X) capable wireless device configured to perform sidelink cellular communications. The wireless device performs sidelink communications using a two-stage sidelink control information (SCI) protocol including Stage 1 SCI messaging carried on a physical sidelink control channel (PSCCH), and Stage 2 SCI messaging carried on a physical sidelink shared channel (PSSCH). The SCI messaging may be encoded using polar codes. Channel interleaving is utilized on the SCI to interleave the SCI between two or more layers of a MIMO transmission system. Scrambling for Stage 2 SCI messaging is performed based on the result of a cyclic redundancy check (CRC) performed on Stage 1 SCI messaging. Collisions between sidelink HARQ feedback to be transmitted to a base station and other transmissions are avoided based on a priority analysis of the sidelink HARQ feedback.
1. A wireless device, comprising:
at least one antenna for performing wireless communications;
a radio coupled to the at least one antenna; and
a processor coupled to the radio;
wherein the wireless device is configured to:
polar encode first sidelink control information to obtain polar encoded first sidelink control information, wherein the first sidelink control information comprises second stage sidelink control information;
perform rate matching on the polar encoded first sidelink control information;
determine a result of a cyclic redundancy check performed on second sidelink control information received over a physical sidelink control channel (PSCCH);
scramble the polar encoded first sidelink control information based at least in part on the result of the cyclic redundancy check; and
transmit the scrambled polar encoded first sidelink information to a remote device on a physical sidelink shared channel (PSSCH).
2. The wireless device of claim 1 ,
wherein scrambling the polar encoded first sidelink control information is performed further based at least in part on an identifier of the remote device.
3. The wireless device of claim 1 ,
wherein scrambling the polar encoded and rate matched first sidelink control information based at least in part on the result of the cyclic redundancy check comprises determining an initialization value of a pseudorandom sequence used for scrambling the polar encoded and rate matched first sidelink control information based at least in part on the result of the cyclic redundancy check, and
wherein the initialization value is determined based at least in part on least significant bits (LSBs) of cyclic redundancy check bits of the second sidelink control information.
4. The wireless device of claim 1 ,
wherein the wireless device is further configured to:
perform a second cyclic redundancy check on third sidelink control information received from the remote device on the PSSCH;
scramble data information based at least in part on one or more of:
the result of the second cyclic redundancy check;
an identifier of the remote device; or
an identifier of the wireless device; and
transmit the scrambled data information to the remote device on the PSSCH.
5. The wireless device of claim 1 ,
wherein the wireless device is further configured to:
scramble a demodulation reference signal based at least in part on the result of the cyclic redundancy check; and
transmit the scrambled demodulation reference signal to the remote device on the PSSCH.
6. The wireless device of claim 1 ,
wherein the wireless device is comprised within a vehicle-to-everything (V2X) communication system.
7. The wireless device of claim 1 ,
wherein the wireless device is installed in a vehicle.
8. An apparatus configured for inclusion within a user equipment (UE) device, the apparatus comprising:
a non-transitory computer-readable memory medium; and
a processor in communication with the memory medium, wherein the processor and the memory medium are configured to cause the UE device to:
polar encode first sidelink control information to obtain polar encoded first sidelink control information, wherein the first sidelink control information comprises second stage sidelink control information;
perform rate matching on the polar encoded first sidelink control information;
determine a result of a cyclic redundancy check performed on second sidelink control information received over a physical sidelink control channel (PSCCH);
scramble the polar encoded first sidelink control information based at least in part on the result of the cyclic redundancy check; and
transmit the scrambled polar encoded first sidelink information to a remote device on a physical sidelink shared channel (PSSCH).
9. The apparatus of claim 8 ,
wherein scrambling the polar encoded first sidelink control information is performed further based at least in part on an identifier of the remote device.
10. The apparatus of claim 8 ,
wherein scrambling the polar encoded and rate matched first sidelink control information based at least in part on the result of the cyclic redundancy check comprises determining an initialization value of a pseudorandom sequence used for scrambling the polar encoded and rate matched first sidelink control information based at least in part on the result of the cyclic redundancy check, and
wherein the initialization value is determined based at least in part on least significant bits (LSBs) of cyclic redundancy check bits of the second sidelink control information.
11. The apparatus of claim 8 ,
wherein the processor and the memory medium are further configured to cause the UE device to:
perform a second cyclic redundancy check on third sidelink control information received from the remote device on the PSSCH;
scramble data information based at least in part on one or more of:
the result of the second cyclic redundancy check;
an identifier of the remote device; or
an identifier of the UE device; and
transmit the scrambled data information to the remote device on the PSSCH.
12. The apparatus of claim 8 ,
wherein the processor and the memory medium are further configured to cause the UE device to:
scramble a demodulation reference signal based at least in part on the result of the cyclic redundancy check; and
transmit the scrambled demodulation reference signal to the remote device on the PSSCH.
13. The apparatus of claim 8 ,
wherein the apparatus is part of a vehicle-to-everything (V2X) communication system.
14. The apparatus of claim 8 ,
wherein the apparatus is installed in a vehicle.
15. A method, comprising:
polar encoding first sidelink control information to obtain polar encoded first sidelink control information, wherein the first sidelink control information comprises second stage sidelink control information;
performing rate matching on the polar encoded first sidelink control information;
determining a result of a cyclic redundancy check performed on second sidelink control information received over a physical sidelink control channel (PSCCH);
scrambling the polar encoded first sidelink control information based at least in part on the result of the cyclic redundancy check; and
transmitting the scrambled polar encoded first sidelink information to a remote device on a physical sidelink shared channel (PSSCH).
16. The method of claim 15 ,
wherein scrambling the polar encoded first sidelink control information is performed further based at least in part on an identifier of the remote device.
17. The method of claim 15 ,
wherein scrambling the polar encoded and rate matched first sidelink control information based at least in part on the result of the cyclic redundancy check comprises determining an initialization value of a pseudorandom sequence used for scrambling the polar encoded and rate matched first sidelink control information based at least in part on the result of the cyclic redundancy check, and
wherein the initialization value is determined based at least in part on least significant bits (LSBs) of cyclic redundancy check bits of the second sidelink control information.
18. The method of claim 15 , wherein the method is performed by a wireless device, the method further comprising:
performing a second cyclic redundancy check on third sidelink control information received from the remote device on the PSSCH;
scrambling data information based at least in part on one or more of:
the result of the second cyclic redundancy check;
an identifier of the remote device; or
an identifier of the wireless device; and
transmitting the scrambled data information to the remote device on the PSSCH.
19. The method of claim 15 , further comprising:
scrambling a demodulation reference signal based at least in part on the result of the cyclic redundancy check; and
transmitting the scrambled demodulation reference signal to the remote device on the PSSCH.
20. The method of claim 15 ,
wherein the method is performed by an apparatus within a vehicle-to-everything (V2X) communication system.