Demodulation reference signal sequence selection in device-to-device communication
A transmitting UE may in a device-to-device (D2D) communication may identify a demodulation reference signal (DMRS) sequence for a D2D transmission based at least in part on a subset of bits of a sidelink control information (SCI) transmission. The subset of bits of the SCI transmission may be selected such that the bits have sufficient variability to reduce the likelihood that multiple UEs may use the same DMRS sequence. The subset of bits of the SCI transmission may be all or a portion of a cyclic redundancy check (CRC) for the SCI.
1. A method for wireless communication, comprising:
identifying sidelink control information (SCI) associated with a sidelink shared channel transmission to be transmitted to one or more receivers;
computing a cyclic redundancy check (CRC) for one or more fields within the SCI;
identifying a demodulation reference signal (DMRS) sequence for use in transmitting the sidelink shared channel transmission based at least in part on the computed CRC;
transmitting a sidelink control channel transmission that includes the SCI and the computed CRC to the one or more receivers; and
transmitting the sidelink shared channel transmission based at least in part on the identified DMRS sequence.
2. The method of claim 1 , wherein the computing the CRC comprises computing the CRC for all fields of the SCI.
3. The method of claim 1 , wherein the DMRS sequence is identified based at least in part on a mapping between a value corresponding to the computed CRC and a plurality of DMRS sequences.
4. The method of claim 3 , wherein the mapping comprises:
determining the value corresponding to the computed CRC; and
determining that the value corresponding to the computed CRC falls within a value range associated with the DMRS sequence of the plurality of DMRS sequences.
5. The method of claim 1 , wherein the method is performed by a transmitting user equipment (UE) and the one or more receivers comprise one or more receiving UEs operating in a device-to-device configuration.
6. The method of claim 1 , wherein the sidelink control channel transmission is transmitted prior to the sidelink shared channel transmission.
7. A method for wireless communication, comprising:
receiving a sidelink control channel transmission that includes sidelink control information (SCI) and a cyclic redundancy check (CRC) from a transmitter;
identifying a demodulation reference signal (DMRS) sequence for use in demodulating a sidelink shared channel transmission associated with the SCI based at least in part on the CRC within the sidelink control channel transmission;
receiving the sidelink shared channel transmission; and
demodulating the sidelink shared channel transmission based at least in part on the identified DMRS sequence.
8. The method of claim 7 , wherein the DMRS sequence is identified based at least in part on a mapping between a value corresponding to the received CRC and a plurality of DMRS sequences.
9. The method of claim 8 , wherein the mapping comprises:
determining the value corresponding to the received CRC; and
determining that the value corresponding to the received CRC falls within a value range associated with the DMRS sequence of the plurality of DMRS sequences.
10. The method of claim 7 , wherein the method is performed by a receiving user equipment (UE) and transmitter comprises a transmitting UE operating in a device-to-device configuration.
11. An apparatus for wireless communication, in a system comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
identify sidelink control information (SCI) associated with a sidelink shared channel transmission to be transmitted to one or more receivers;
compute a cyclic redundancy check (CRC) for one or more fields within the SCI;
identify a demodulation reference signal (DMRS) sequence for use in transmitting the sidelink shared channel transmission based at least in part on the computed CRC;
transmit a sidelink control channel transmission that includes the SCI and the computed CRC to the one or more receivers; and
transmit the sidelink shared channel transmission based at least in part on the identified DMRS sequence.
12. The apparatus of claim 11 , wherein the computing the CRC comprises computing the CRC for all fields of the SCI.
13. The apparatus of claim 11 , wherein the DMRS sequence is identified based at least in part on a mapping between a value corresponding to the computed CRC and a plurality of DMRS sequences.
14. The apparatus of claim 13 , wherein the mapping comprises:
determining the value corresponding to the computed CRC; and
determining that the value corresponding to the computed CRC falls within a value range associated with the DMRS sequence of the plurality of DMRS sequences.
15. The apparatus of claim 11 , wherein the apparatus comprises a transmitting user equipment (UE) and the one or more receivers comprise one or more receiving UEs operating in a device-to-device configuration.
16. The apparatus of claim 11 , wherein the sidelink control channel transmission is transmitted prior to the sidelink shared channel transmission.
17. An apparatus for wireless communication, in a system comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
receive a sidelink control channel transmission that includes sidelink control information (SCI) and a cyclic redundancy check (CRC) from a transmitter;
identify a demodulation reference signal (DMRS) sequence for use in demodulating a sidelink shared channel transmission associated with the SCI based at least in part on the CRC within the sidelink control channel transmission;
receive the sidelink shared channel transmission; and
demodulate the sidelink shared channel transmission based at least in part on the identified DMRS sequence.
18. The apparatus of claim 17 , wherein the DMRS sequence is identified based at least in part on a mapping between a value corresponding to the received CRC and a plurality of DMRS sequences.
19. The apparatus of claim 18 , wherein the instructions are further operable to cause the apparatus to:
determine the value corresponding to the received CRC; and
determine that the value corresponding to the received CRC falls within a value range associated with the DMRS sequence of the plurality of DMRS sequences.
20. The apparatus of claim 17 , wherein the apparatus comprises a receiving user equipment (UE) and the transmitter comprises a transmitting UE operating in a device-to-device configuration.