Method and apparatus for transmitting sidelink reference signal in NR V2X
Provided herein is a method for performing, by a first apparatus, wireless communication and an apparatus for supporting the same. The method may include the steps of generating a Phase Tracking-Reference Signal (PT-RS), transmitting a Physical Sidelink Control Channel (PSCCH) to a second apparatus, mapping, based on a Cyclic Redundancy Check (CRC) on the PSCCH, the PT-RS to a subcarrier on a Physical Sidelink Shared Channel (PSSCH) resource related to the PSCCH, and transmitting the PT-RS to the second apparatus.
1. A method for performing, by a first apparatus, wireless communication, the method comprising:
generating a Phase Tracking-Reference Signal (PT-RS);
transmitting, to a second apparatus, a sidelink control information (SCI) on a Physical Sidelink Control Channel (PSCCH);
obtaining Resource Block (RB) offset related to the PT-RS based on a Cyclic Redundancy Check (CRC) on the PSCCH;
mapping, based on the RB offset related to the PT-RS, the PT-RS to a subcarrier on a Physical Sidelink Shared Channel (PSSCH) resource related to the PSCCH; and
transmitting, to the second apparatus, the PT-RS on the PSSCH resource.
2. The method of claim 1 , wherein a subcarrier offset related to the PT-RS is obtained based on the CRC on the PSCCH.
3. The method of claim 2 , wherein the PT-RS is mapped to the subcarrier on the PSSCH resource, based on (i) a subcarrier having a lowest index, among indexes of multiple subcarriers on the PSSCH resource, and (ii) the subcarrier offset.
4. The method of claim 1 , wherein the RB offset is an RB unit offset between a first RB having a lowest index and a second RB to which the PT-RS is mapped.
5. The method of claim 1 , wherein the PT-RS is mapped to the subcarrier within multiple RBs on the PSSCH resource, based on (i) an RB having a lowest index among indexes of the multiple RBs on the PSSCH resource, and (ii) the RB offset.
6. The method of claim 1 , wherein a subcarrier offset related to the PT-RS is obtained based on the RB offset related to the PT-RS and a Resource Element (RE) offset related to the PT-RS.
7. The method of claim 6 , wherein the RE offset related to the PT-RS is pre-configured for the first apparatus.
8. The method of claim 1 , wherein the PSSCH resource includes multiple RBs being allocated for the first apparatus for PSSCH transmission.
9. The method of claim 1 , further comprising:
receiving configuration information related to the PT-RS from a base station.
10. The method of claim 9 , wherein the configuration information related to the PT-RS includes at least one of information related to time-axis density of the PT-RS or information related to frequency-axis density of the PT-RS.
11. The method of claim 1 , wherein the PT-RS is not mapped on a PSCCH resource.
12. The method of claim 1 , wherein a number of antenna ports related to the PT-RS is equal to a number of antenna ports related to a Demodulation Reference Signal (DMRS) on the PSSCH resource.
13. The method of claim 12 , wherein an association between the antenna ports related to the PT-RS and the antenna ports related to the DMRS on the PSSCH resource is fixed.
14. A first apparatus for performing wireless communication, the first apparatus comprising:
one or more memories storing instructions;
one or more transceivers; and
one or more processors connected to the one or more memories and the one or more transceivers, wherein the one or more processors execute the instructions to:
generate a Phase Tracking-Reference Signal (PT-RS),
transmit, to a second apparatus, a sidelink control information (SCI) on a Physical Sidelink Control Channel (PSCCH),
obtain Resource Block (RB) offset related to the PT-RS based on a Cyclic Redundancy Check (CRC) on the PSCCH,
map, based on the RB offset related to the PT-RS, the PT-RS to a subcarrier on a Physical Sidelink Shared Channel (PSSCH) resource related to the PSCCH, and
transmit, to the second apparatus, the PT-RS on the PSSCH resource.
15. An apparatus configured to control a first user equipment (UE), the apparatus comprising:
one or more processors; and
one or more memories connected to the one or more processors and storing instructions, wherein the one or more processors execute the instructions to:
generate a Phase Tracking-Reference Signal (PT-RS),
transmit, to a second apparatus, a sidelink control information (SCI) on a Physical Sidelink Control Channel (PSCCH),
obtain Resource Block (RB) offset related to the PT-RS based on a Cyclic Redundancy Check (CRC) on the PSCCH,
map, based on the RB offset related to the PT-RS, the PT-RS to a subcarrier on a Physical Sidelink Shared Channel (PSSCH) resource related to the PSCCH, and
transmit, to the second apparatus, the PT-RS on the PSSCH resource.