Power control for new radio uplink single-user multiple-input-multiple-output communication

1. A User Equipment (UE) having a plurality of transmit chains that do not support relative transmit phase continuity, the UE comprising:

processing circuitry configured to:

derive a power P to be used for uplink power control for a physical uplink shared channel transmission; and

determine a power to be used for a set of antenna ports based on the power P according to a rule that depends on whether the UE is utilizing codebook based transmission or non-codebook based transmission for the physical uplink shared channel transmission, the set of antenna ports being antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power,

wherein the rule is such that, for a case of codebook based transmission, in order to determine the power to be used for the set of antenna ports based on the power P according to the rule, the processing circuitry is further configured to:

derive a second power P′ by scaling the power P with a ratio, R, wherein the ratio R is a first number antenna ports divided by a second number of antenna ports, wherein the first number of antenna ports is a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power, and the second number of antenna ports is determined according to a multi-antenna transmission configuration as a third number of spatial layers indicated by a gNB; and

equally divide the second power P′ across the set of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power.

2. The UE of claim 1 wherein the UE further comprises an interface, and the processing circuitry is further configured to transmit, via the interface, the physical uplink shared channel transmission using the set of antenna ports.

3. The UE of claim 1 wherein the number of antenna ports at the UE is the number of Sounding Reference Signal, SRS, ports in an SRS resource at the UE.

4. The UE of claim 1 wherein the rule is such that the second power P′ may equal the power P for rank 1 transmission for:

at least two UE capabilities from a group of UE capabilities consisting of: a capability to perform full coherence transmission, a capability to perform partial coherence transmission, and a capability to perform non-coherence transmission; and/or

both codebook based and non-codebook based transmission.

5. The UE claim 1 , wherein the UE has a capability of supporting non-coherent transmission but does not have a capability of supporting partially coherent or coherent transmission.

6. The UE of claim 1 wherein the ratio R is derived by selecting the ratio from a set of predetermined values.

7. A method implemented in a User Equipment (UE) having a plurality of transmit chains that do not support relative transmit phase continuity, the method comprising:

deriving a power P to be used for uplink power control for a physical uplink shared channel transmission; and

determining a power to be used for a set of antenna ports based on the power P according to a rule that depends on whether the UE is utilizing codebook based transmission or non-codebook based transmission for the physical uplink shared channel transmission, the set of antenna ports being antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power,

wherein the rule is such that, for a case of codebook based transmission, determining the power to be used for the set of antenna ports based on the power P according to the rule comprises:

deriving a second power P′ by scaling the power P with a ratio, R, wherein the ratio R is a first number antenna ports divided by a second number of antenna ports, wherein the first number of antenna ports is a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power, and the second number of antenna ports is determined according to a multi-antenna transmission configuration as a third number of spatial layers indicated by a gNB; and

equally dividing the second power P′ across the set of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power.

8. The method of claim 7 , further comprising transmitting the physical uplink shared channel transmission using the set of antenna ports.

9. The method of 7 , wherein the number of antenna ports at the UE is the number of Sounding Reference Signal, SRS, ports in an SRS resource at the UE.

10. The method of claim 7 , wherein the UE has a capability of supporting non-coherent transmission but does not have a capability of supporting partially coherent or coherent transmission.

11. The method of claim 7 , wherein the ratio R is derived by selecting the ratio from a set of predetermined values.