Determining resources for phase tracking reference signals

1. A method performed by a base station, the method comprising:

determining a first set of resources, wherein the first set of resources are used for non-zero power (NZP) phase tracking reference signals (PTRS) (NZP-PTRSs) for a first downlink transmission and zero power (ZP) PTRS (ZP-PTRSs) for a second downlink transmission;

determining a second set of resources, wherein the second set of resources are used for ZP-PTRSs for the first downlink transmission and NZP-PTRSs for the second downlink transmission; and

transmitting, to a user equipment (UE), the first downlink transmission using the first set of resources and the second set of resources, wherein the first downlink transmission is transmitted concurrently with the second downlink transmission.

2. The method of claim 1 , further comprising transmitting the second downlink transmission using the first set of resources and the second set of resources.

3. The method of claim 1 , wherein the first downlink transmission and the second downlink transmission are transmitted via physical downlink shared channels.

4. The method of claim 1 , wherein the first set of resources and the second set of resources are determined based on one or more parameters.

5. The method of claim 4 , wherein the one or more parameters are configured via radio resource control signaling.

6. The method of claim 4 , wherein the one or more parameters comprise nNZP-PTRS , nZP-PTRS , k RE ref-NZP , and k RE ref-ZP .

7. The method of claim 6 , wherein nNZP-PTRS and nZP-PTRS are different.

8. The method of claim 6 , wherein nNZP-PTRS and nZP-PTRS are the same.

9. The method of claim 1 , wherein subcarriers corresponding to the zero power phase tracking reference signals do not carry phase tracking reference signals or data for physical downlink shared channel transmissions.

10. The method of claim 1 , wherein subcarriers corresponding to the non-zero power phase tracking reference signals are configured to carry phase tracking reference signals or data for physical downlink shared channel transmissions.

11. The method of claim 10 , wherein each of the subcarriers corresponding to the non-zero power phase tracking reference signals carry data for a corresponding physical downlink shared channel transmission if the respective subcarrier does not carry phase tracking reference signals for the corresponding physical downlink shared channel transmission.

12. A base station, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the base station to:

determine a first set of resources, wherein the first set of resources are used for non-zero power (NZP) phase tracking reference signals (PTRS) (NZP-PTRSs) for a first downlink transmission and zero power (ZP) PTRS (ZP-PTRSs) for a second downlink transmission;

determine a second set of resources, wherein the second set of resources are used for ZP-PTRSs for the first downlink transmission and NZP-PTRSs for the second downlink transmission; and

transmit, to a user equipment (UE), the first downlink transmission using the first set of resources and the second set of resources, wherein the first downlink transmission is transmitted concurrently with the second downlink transmission.

13. A method performed by a user equipment (UE), the method comprising:

receiving a first downlink transmission using a first set of resources and a second set of resources; and

receiving a second downlink transmission using the first set of resources and the second set of resources, wherein:

the first downlink transmission is received concurrently with the second downlink transmission;

the first set of resources are used for non-zero power (NZP) phase tracking reference signals (PTRS) (NZP-PTRSs) for the first downlink transmission and zero power (ZP) PTRS (ZP-PTRSs) for the second downlink transmission; and

the second set of resources are used for ZP-PTRSs for the first downlink transmission and NZP-PTRSs for the second downlink transmission.

14. The method of claim 13 , wherein the first downlink transmission and the second downlink transmission are received via physical downlink shared channels.

15. The method of claim 13 , wherein the first set of resources and the second set of resources are determined based on one or more parameters.

16. The method of claim 15 , wherein the one or more parameters are configured via radio resource control signaling.

17. The method of claim 15 , wherein the one or more parameters comprise nNZP-PTRS , nZP-PTRS , k RE ref-NZP , and k RE ref-ZP .

18. The method of claim 13 , wherein subcarriers corresponding to the zero power phase tracking reference signals do not carry phase tracking reference signals or data for physical downlink shared channel transmissions.

19. The method of claim 13 , wherein subcarriers corresponding to the non-zero power phase tracking reference signals are configured to carry phase tracking reference signals or data for physical downlink shared channel transmissions.

20. A user equipment (UE), comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

receive a first downlink transmission using a first set of resources and a second set of resources; and

receive a second downlink transmission using the first set of resources and the second set of resources, wherein:

the first downlink transmission is received concurrently with the second downlink transmission;

the first set of resources are used for non-zero power (NZP) phase tracking reference signals (PTRS) (NZP-PTRSs) for the first downlink transmission and zero power (ZP) PTRS (ZP-PTRSs) for the second downlink transmission; and

the second set of resources are used for ZP-PTRSs for the first downlink transmission and NZP-PTRSs for the second downlink transmission.