Method of receiving phase tracking reference signal by user equipment in wireless communication system and device for supporting same
A method of receiving phase tracking reference signal (PT-RS) by a user equipment (UE) in a wireless communication system, the method includes determining one or more resource blocks to which the PT-RS is mapped among N resource blocks allocated to the UE; and receiving the PT-RS via the one or more second resource blocks, wherein the N resource blocks are indexed as second resource block indices 0 to N−1 from a resource block having a lowest index of first resource block indices to a resource block having a highest index of the first resource block indices, wherein the PT-RS is mapped to the one or more resource blocks having indices of the second resource block indices and the indices are determined based on a first value related to a frequency density of the PT-RS and a second value related to a resource block offset, wherein the first value is determined based on a scheduled bandwidth related with the N resource blocks allocated to the UE, and wherein N is a natural number.
1. A method of receiving, by a user equipment (UE), a phase tracking reference signal (PT-RS) in a wireless communication system, the method comprising:
determining, among a plurality of resource blocks that are sequentially numbered according to first indices, N resource blocks that are allocated to the UE, wherein the N resource blocks are sequentially numbered from 0 to N−1 according to second indices that are different from the first indices, where N is a natural number;
determining, among the N resource blocks allocated to the UE, one or more resource blocks having subcarriers to which the PT-RS is mapped; and
receiving the PT-RS via the one or more resource blocks,
wherein determining the one or more resource blocks having subcarriers to which the PT-RS is mapped is based on (i) a first value related to a frequency density of the PT-RS, and (ii) a second value related to a resource block offset,
wherein the first value is related to a scheduled bandwidth for the N resource blocks allocated to the UE, and
wherein determining the one or more resource blocks having subcarriers to which the PT-RS is mapped comprises:
determining the one or more resource blocks as being spaced apart from each other by the first value according to the second indices, and
determining an offset for a lowest scheduled resource block among the one or more resource blocks based on the second value.
2. The method of claim 1 , wherein the frequency density of the PT-RS is equal to either one PT-RS every two resource blocks or one PT-RS every four resource blocks.
3. The method of claim 1 , further comprising receiving information related to one or more subcarrier candidates, in the one or more resource blocks, to which the PT-RS can be mapped.
4. The method of claim 3 , further comprising:
determining a location of the subcarriers to which the PT-RS is mapped, among the one or more subcarrier candidates, based on a frequency location of a demodulation reference signal (DM-RS) port associated with the PT-RS.
5. The method of claim 4 , wherein the PT-RS is mapped to at least one symbol that is subsequent to a symbol to which the associated DM-RS port is mapped within the subcarriers to which the PT-RS is mapped.
6. The method of claim 5 , wherein a time-domain pattern for mapping the PT-RS to the at least one symbol is based on a modulation and coding scheme (MCS) scheduled to the UE.
7. The method of claim 3 , wherein the information related to one or more subcarrier candidates is received through higher layer signaling.
8. The method of claim 1 , wherein based on a plurality of PT-RSs being received through two PT-RS ports, and based on the two PT-RS ports being respectively associated with a plurality of demodulation reference signal (DM-RS) ports which are code division multiplexed in a time domain (CDM-T):
each of the plurality of PT-RSs received through the two PT-RS ports are mapped to different resource blocks.
9. The method of claim 1 , wherein determining the one or more resource blocks having subcarriers to which the PT-RS is mapped further comprises: determining, among the second indices, one or more second indices i that correspond to the one or more resource blocks according to: i=k*(first value)+(second value), where k=0, 1, . . . n.
10. A user equipment (UE) configured to receive a phase tracking reference signal (PT-RS) in a wireless communication system, the UE comprising:
at least one transceiver;
at least one processor; and
at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations comprising:
determining, among a plurality of resource blocks that are sequentially numbered according to first indices, N resource blocks that are allocated to the UE, wherein the N resource blocks are sequentially numbered from 0 to N−1 according to second indices that are different from the first indices, where N is a natural number;
determining, among the N resource blocks allocated to the UE, one or more resource blocks having subcarriers to which the PT-RS is mapped; and
receiving, through the at least one transceiver, the PT-RS via the one or more resource blocks,
wherein determining the one or more resource blocks having subcarriers to which the PT-RS is mapped is based on (i) a first value related to a frequency density of the PT-RS, and (ii) a second value related to a resource block offset,
wherein the first value is related to a scheduled bandwidth for the N resource blocks allocated to the UE, and
wherein determining the one or more resource blocks having subcarriers to which the PT-RS is mapped comprises:
determining the one or more resource blocks as being spaced apart from each other by the first value according to the second indices, and
determining an offset for a lowest scheduled resource block among the one or more resource blocks based on the second value.
11. The UE of claim 10 , wherein the frequency density of the PT-RS is equal to either one PT-RS every two resource blocks or one PT-RS every four resource blocks.
12. The UE of claim 10 , wherein the operations further comprise:
receiving, through the at least one transceiver, information related to one or more subcarrier candidates, in the one or more resource blocks, to which the PT-RS can be mapped.
13. The UE of claim 12 , wherein the operations further comprise:
determining a location of the subcarriers to which the PT-RS is mapped, among the one or more subcarrier candidates, based on a frequency location of a demodulation reference signal (DM-RS) port associated with the PT-RS.
14. The UE of claim 13 , wherein the PT-RS is mapped to at least one symbol that is subsequent to a symbol to which the associated DM-RS port is mapped within the subcarriers to which the PT-RS is mapped.
15. The UE of claim 14 , wherein a time-domain pattern for mapping the PT-RS to the at least one symbol is based on a modulation and coding scheme (MCS) scheduled to the UE.
16. The UE of claim 12 , wherein the information related to one or more subcarrier candidates is received through higher layer signaling.
17. The UE of claim 10 , wherein based on a plurality of PT-RSs being received through two PT-RS ports, and based on the two PT-RS ports being respectively associated with a plurality of demodulation reference signal (DM-RS) ports which are code division multiplexed in a time domain (CDM-T):
each of the plurality of PT-RSs received through the two PT-RS ports are mapped to different resource blocks.
18. The UE of claim 10 , wherein determining the one or more resource blocks having subcarriers to which the PT-RS is mapped further comprises: determining, among the second indices, one or more second indices i that correspond to the one or more resource blocks according to: i=k*(first value)+(second value), where k=0, 1, . . . n.