Method for uplink transmission and reception in wireless communication system and apparatus therefor
Disclosed is a method for uplink transmission and reception in a wireless communication system and an apparatus therefor. Particularly, a method for performing uplink transmission by a user equipment (UE) in a wireless communication system includes: receiving sounding reference signal (SRS) resource configuration information form a base station, in which the SRS resource configuration information includes SRS resource information and association configuration information between a first SRS and a second SRS that is a target of the SRS resource configuration information; and transmitting precoded the second SRS to the base station on an SRS resource indicated by the SRS resource information, and the second SRS may be transmitted based on the precoding applied to the first SRS indicated by the association configuration information.
1. A method of performing uplink transmission by a user equipment (UE) in a wireless communication system, the method comprising:
receiving, from a base station, configuration information for a first sounding reference signal (SRS) that specifies a relation between the first SRS and a second SRS that is a reference for spatial beamforming of the first SRS; and
based on the configuration information for the first SRS specifying the relation between the first SRS and the second SRS: transmitting the first SRS to the base station by applying, to the first SRS, a first spatial beamforming that is identical to a second spatial beamforming used for transmission of the second SRS,
wherein the method further comprises:
receiving, from the base station, downlink control information (DCI) for uplink scheduling, wherein the DCI comprises an SRS resource indication (SRI); and
determining a bit width of an SRI field in the DCI,
wherein the SRI field carries the SRI, and
wherein the bit width is determined based on a number of SRS resources in an SRS resource set configured for the UE.
2. The method of claim 1 , wherein the configuration information for the first SRS specifying the relation between the first SRS and the second SRS comprises (i) resource information for the first SRS or (ii) antenna port information for the first SRS.
3. The method of claim 1 , wherein transmitting the first SRS to the base station comprises performing an operation that is configured by the base station.
4. The method of claim 3 , wherein the operation comprises an uplink data scheduling operation and a beam management operation.
5. The method of claim 4 , wherein the first spatial beamforming is applied to the first SRS for the uplink data scheduling operation so as to form beams of the same direction in all SRS antenna ports configured in a single SRS resource.
6. The method of claim 4 , wherein the first spatial beamforming is applied to the first SRS for the beam management operation so as to form beams of different directions for each SRS antenna port configured in a single SRS resource.
7. The method of claim 1 , wherein transmitting the first SRS to the base station comprises:
periodically transmitting or aperiodically transmitting the first SRS to the base station based on triggering by the DCI received from the base station.
8. The method of claim 1 , wherein the second SRS, which is the reference for spatial beamforming of the first SRS, is an SRS that was most recently transmitted by the UE before transmitting the first SRS.
9. The method of claim 1 , wherein the bit width is determined based further on a maximum number of layers supported for uplink transmission, and
wherein determining the bit width of the SRI field is based on an equation:
┌log 2 S tot ┐
wherein ┌⋅┐ represents a ceiling function,
wherein
S
tot
=
∑
k
=
1
L
max
(
N
k
)
,
wherein N represents the number of SRS resources in the SRS resource set configured for the UE, and
wherein L max represents the maximum number of layers supported for the uplink transmission.
10. The method of claim 1 , further comprising:
performing an uplink transmission on an SRS antenna port that is transmitted in an SRS resource that is selected by the SRI.
11. The method of claim 10 , wherein performing the uplink transmission comprises:
performing the uplink transmission using a non-codebook based transmission.
12. The method of claim 1 , wherein the configuration information for the first SRS specifies the relation between the first SRS and the second SRS by identifying the second SRS as a reference SRS for the first SRS.
13. A user equipment (UE) configured to perform uplink transmission in a wireless communication system, the UE comprising:
a radio frequency (RF) unit;
at least one processor; and
at least one computer memory operably connectable to the least one processor and storing instructions that, when executed, cause the at least one processor to perform operations comprising:
receiving, from a base station and through the RF unit, configuration information for a first sounding reference signal (SRS) that specifies a relation between the first SRS and a second SRS that is a reference for spatial beamforming of the first SRS; and
based on the configuration information for the first SRS specifying the relation between the first SRS and the second SRS: transmitting, through the RF unit, the first SRS to the base station by applying, to the first SRS, a first spatial beamforming that is identical to a second spatial beamforming used for transmission of the second SRS,
wherein the operations further comprise:
receiving, from the base station, downlink control information (DCI) for uplink scheduling, wherein the DCI comprises an SRS resource indication (SM); and
determining a bit width of an SRI field in the DCI,
wherein the SRI field carries the SRI, and
wherein the bit width is determined based on a number of SRS resources in an SRS resource set configured for the UE.