Power control for New Radio uplink single-user Multiple-Input-Multiple-Output communication

1. A User Equipment, 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 scaling ratio to apply to the power P before splitting the scaled power P equally across a set of antenna ports on which the UE transmits the physical uplink shared channel transmission with non-zero power, the power scaling ratio being determined according to a rule that depends on which of two types of transmissions the UE is utilizing for the physical uplink shared channel transmission, the two types including codebook based transmission and non-codebook based transmission.

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 rule is such that, for a case of non-codebook based transmission, the power scaling ratio is 1.

4. The UE of claim 1 wherein the rule is such that, for a case of codebook based transmission, the power scaling ratio is a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power divided by a number of antenna ports at the UE.

5. The UE of claim 4 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.

6. The UE of claim 4 wherein the ratio is derived by selecting the ratio from a set of predetermined values.

7. The UE of claim 1 wherein the rule is such that, 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 ratio α_=K ρ_0/ρ where ρ is a number of antenna ports used for the physical uplink shared channel transmission, ρ_0 is a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power, and:

K=1 if the UE has full coherence transmission capability in case of codebook based transmission;

K=2 if the UE has partial coherence transmission capability in case of codebook based transmission with four antenna ports; and

K=2 or K=4 if the UE has non-coherence transmission capability in case of codebook based transmission and two or four antenna ports, respectively;

derive a second power P′ by scaling the power P with a ratio β=min{1,α}; 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.

8. A method implemented in a User Equipment, UE, 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 scaling ratio to apply to the power P before splitting the scaled power P equally across a set of antenna ports on which the UE transmits the physical uplink shared channel transmission with non-zero power, the power scaling ratio being determined according to a rule that depends on which of two types of transmissions the UE is utilizing for the physical uplink shared channel transmission, the two types including codebook based transmission and non-codebook based transmission.

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

10. The method of claim 8 wherein the rule is such that, for a case of non-codebook based transmission, the power scaling ratio is 1.

11. The method of claim 8 wherein the rule is such that, for a case of codebook based transmission, the power scaling ratio is a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power divided by a number of antenna ports at the UE.

12. The method of claim 11 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.

13. The method of claim 8 wherein the rule is such that determining the power scaling ratio to apply to the power P according to the rule comprises:

deriving a ratio α_=K ρ_0/ρ where ρ is a number of antenna ports used for the physical uplink shared channel transmission, ρ_0 is a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power, and:

K=1 if the UE has full coherence transmission capability in case of codebook based transmission;

K=2 if the UE has partial coherence transmission capability in case of codebook based transmission with four antenna ports; and

K=2 or K=4 if the UE has non-coherence transmission capability in case of codebook based transmission and two or four antenna ports, respectively;

deriving a second power P′ by scaling the power P with a ratio β=min{1,α}; 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.

14. The method of claim 8 wherein the power scaling ratio is derived as a function depending on a capability of the UE in terms of full coherence, partial coherence, or non-coherence transmission;

a number of antenna ports, in the set of antenna ports, on which a non-zero physical uplink shared channel is transmitted;

a number of antenna ports, in the set of antenna ports, used for the physical uplink shared channel transmission; and/or

a number of antenna ports, in the set of antenna ports, at the UE.

15. A method implemented in a User Equipment, UE, the method comprising:

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

determining a power to be used for a set of antenna ports based on the power P according to a rule that depends on a capability of the UE in terms of full coherence, partial coherence, or non-coherence transmission, the set of antenna ports being antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power; and

equally dividing the determined power across the set of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power,

wherein determining the power to be used for the set of antenna ports based on the power P further includes scaling the power P by a ratio that is determined in dependence on which of two types of transmissions the UE is utilizing for the physical uplink shared channel transmission, the two types including codebook based transmission and non-codebook based transmission.

16. The method of claim 15 wherein, for a case of codebook based transmission, scaling the power P by a ratio comprises:

scaling the power P with a ratio of a number of antenna ports on which the physical uplink shared channel transmission is transmitted with non-zero power to a number of antenna ports at the UE.