Method for transmitting and receiving uplink phase tracking reference signal and devices supporting the same
According to the present invention, a method of transmitting and receiving an uplink phase tracking reference signal between a user equipment and a base station in a wireless communication and an apparatus supporting the same are disclosed. According to an example applicable to the present invention, a user equipment can transmit an uplink PT-RS to a base station using the actual number of PT-RS ports which is determined based on the maximum uplink phase tracking reference signal (PT-RS) ports received from the base station and a precoding matrix set to the UE.
1. A method for transmitting a phase tracking reference signal (PT-RS) by a user equipment (UE) in a wireless communication system, the method comprising:
receiving information on a maximum number of uplink PT-RS ports from a base station; and
transmitting the PT-RS based on an actual number of uplink PT-RS ports to the base station,
wherein the actual number of uplink PT-RS ports is determined based on the information on the maximum number of uplink PT-RS ports and a precoding matrix configured to the UE, such that, when the precoding matrix is a partial-coherent precoding matrix or non-coherent precoding matrix, the actual number of uplink PT-RS ports is determined to be the maximum number of uplink PT-RS ports.
2. The method of claim 1 , wherein the information on the maximum number of uplink PT-RS ports is received via higher layer signaling.
3. The method of claim 1 , wherein the actual number of uplink PT-RS ports is equal to or smaller than the maximum number of uplink PT-RS ports.
4. The method of claim 1 , wherein the precoding matrix configured to the UE is configured based on a transmitted precoding matrix indicator (TPMI).
5. The method of claim 1 , wherein, when the precoding matrix is a full-coherent precoding matrix configured to the UE, the actual number of uplink PT-RS ports is determined as 1 regardless of the maximum number of uplink PT-RS ports.
6. The method of claim 1 , wherein the actual number of uplink PT-RS ports determined based on the partial-coherent precoding matrix or non-coherent precoding matrix configured to the UE is determined under the assumption that:
one or more first antenna ports having a non-zero value in a first column of the precoding matrix have an identical phase noise source, and
one or more second antenna ports having non-zero value in a different column from the first column of the precoding matrix have a different phase noise from the one or more first antenna ports.
7. The method of claim 1 , wherein the UE is configured with one or more sounding reference signal (SRS) resources.
8. The method of claim 7 , wherein the one or more SRS resources are configured by one or more SRS resource indications (SRIs).
9. The method of claim 8 , wherein the one or more SRIs are received via downlink control information (DCI).
10. The method of claim 7 , wherein the actual number of uplink PT-RS ports is determined additionally based on a number of SRS resources configured to the UE.
11. A communication device for transmitting an uplink phase tracking reference signal (PT-RS) in a wireless communication system, the communication device comprising:
a memory; and
a processor operably coupled with the memory and configured to:
receive information on a maximum number of uplink PT-RS ports from a base station; and
transmit the PT-RS based on an actual number of uplink PT-RS ports to the base station,
wherein the actual number of uplink PT-RS ports is determined based on the information on the maximum number of uplink PT-RS ports and a precoding matrix configured to the UE, such that, when the precoding matrix is a partial-coherent precoding matrix or non-coherent precoding matrix, the actual number of uplink PT-RS ports is determined to be the maximum number of uplink PT-RS ports.
12. The communication device of claim 11 ,
wherein the information on the maximum number of uplink PT-RS ports is received via higher layer signaling, and
wherein the precoding matrix configured to the communication device is configured based on downlink control information (DCI) or higher layer signaling.
13. The communication device of claim 11 , wherein, when the precoding matrix is a full-coherent precoding matrix configured to the communication device, the actual number of uplink PT-RS ports is determined as 1 regardless of the maximum number of uplink PT-RS ports.
14. A communication device for receiving an uplink phase tracking reference signal (PT-RS) in a wireless communication system, the communication device comprising:
a memory; and
a processor operably coupled with the memory and configured to:
transmit information on a maximum number of uplink PT-RS ports to a user equipment; and
receive the PT-RS based on an actual number of uplink PT-RS ports from the user equipment,
wherein the actual number of uplink PT-RS ports is determined based on the information on the maximum number of uplink PT-RS ports and a precoding matrix configured to the UE, such that, when the precoding matrix is a partial-coherent precoding matrix or non-coherent precoding matrix, the actual number of uplink PT-RS ports is determined to be the maximum number of uplink PT-RS ports.