Methods and apparatuses for positioning based on the sounding reference signal

1. A method performed by a user equipment, UE, the method comprising:

obtaining a Sounding Reference Signal, SRS, configuration from a network node;

determining an SRS waveform that is adapted for positioning based on the SRS configuration to have a full bandwidth within a bandwidth configured for the SRS waveform, wherein the SRS waveform is transmitted on every fourth subcarrier of an SRS transmission bandwidth associated with the SRS waveform, wherein a plurality of time resources for the SRS waveform comprises an SRS resource set, wherein the SRS resource set comprises four time resources, and wherein, compared to an SRS transmission in the first time resource in the SRS resource set, a frequency offset for an SRS transmission in the second time resource in the SRS resource set is 2 subcarriers, a frequency offset for an SRS transmission in the third time resource in the SRS resource set is 1 subcarrier, and a frequency offset for an SRS transmission in the fourth time resource in the SRS resource set is 3 subcarriers; and

transmitting the SRS waveform.

2. The method of claim 1 , wherein the SRS waveform uses, for a comb value of n (comb-n) SRS resource, wherein n is an integer 4, every subcarrier in a combination of n Orthogonal Frequency Division Multiplexing, OFDM, symbols in all Physical Resource Blocks, PRBs, applicable for the SRS waveform.

3. The method of claim 1 , wherein:

the UE is configured with n comb value of n (comb-n) SRS resources, indexed i=0, 1, . . . , n−1, wherein

n is an integer 4, and

each of the n resources of the n comb-n SRS resources is with a different subcarrier shift modulo (i+b, n) where b is 0, 1, . . . n−1.

4. The method of claim 3 , wherein each of the n comb-n SRS resources of the n comb-n SRS resources has a duration of one OFDM symbol.

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

transmitting an SRS configuration to a user equipment, UE; and

receiving, from the UE, an SRS waveform adapted for positioning based on the SRS configuration, the SRS waveform having a full bandwidth within a bandwidth configured for the SRS waveform, wherein the SRS waveform is received on every fourth subcarrier of an SRS transmission bandwidth associated with the SRS waveform, wherein a plurality of time resources for the SRS waveform comprises an SRS resource set, wherein the SRS resource set comprises four time resources, and wherein, compared to an SRS transmission in the first time resource in the SRS resource set, a frequency offset for an SRS transmission in the second time resource in the SRS resource set is 2 subcarriers, a frequency offset for an SRS transmission in the third time resource in the SRS resource set is 1 subcarrier, and a frequency offset for an SRS transmission in the fourth time resource in the SRS resource set is 3 subcarriers.

6. The method of claim 5 , wherein the SRS waveform uses, for a comb value of n (comb-n) SRS resource, wherein n is an integer 4, every subcarrier in a combination of n Orthogonal Frequency Division Multiplexing, OFDM, symbols in all Physical Resource Blocks, PRBs, applicable for the SRS waveform.

7. The method of claim 5 , wherein:

the UE is configured with n comb value of n (comb-n) SRS resources, indexed i=0, 1, . . . , n−1, wherein

n is an integer 4, and

each of the n resources of the n comb-n SRS resources is with a different subcarrier shift modulo (i+b, n) where b is 0, 1, . . . n−1.

8. The method of claim 7 , wherein each of the n comb-n SRS resources of the n comb-n SRS resources has a duration of one OFDM symbol.

9. The method of claim 7 , wherein n=4 and the four comb-4 SRS resources are of a length of one OFDM symbol and are configured to be transmitted in the same slot.

10. The method of claim 7 , wherein n=4 and the four comb-4 SRS resources are of a length of four OFDM symbols and are configured to be transmitted in four different slots.

11. The method of claim 5 further comprising:

obtaining the SRS configuration from a location server;

adding together a plurality of symbols of the SRS waveform to get a concatenated signal utilizing all subcarriers;

performing a positioning measurement based on the SRS waveform; and

sending the positioning measurement to the location server for use in positioning.

12. A user equipment, UE, comprising:

processing circuitry

configured to:

obtain a Sounding Reference Signal, SRS, configuration from a network node;

determine an SRS waveform that is adapted for positioning based on the SRS configuration to have a full bandwidth within a bandwidth configured for the SRS waveform, wherein the SRS waveform is transmitted on every fourth subcarrier of an SRS transmission bandwidth associated with the SRS waveform, wherein a plurality of time resources for the SRS waveform comprises an SRS resource set, wherein the SRS resource set comprises four time resources, and wherein, compared to an SRS transmission in the first time resource in the SRS resource set, a frequency offset for an SRS transmission in the second time resource in the SRS resource set is 2 subcarriers, a frequency offset for an SRS transmission in the third time resource in the SRS resource set is 1 subcarrier, and a frequency offset for an SRS transmission in the fourth time resource in the SRS resource set is 3 subcarriers; and

transmit the SRS waveform.

13. The UE of claim 12 , wherein the SRS waveform uses, for a comb value of n (comb-n) SRS resource, wherein n is an integer 4, every subcarrier in a combination of n Orthogonal Frequency Division Multiplexing, OFDM, symbols in all Physical Resource Blocks, PRBs, applicable for the SRS waveform.

14. The UE of claim 12 , wherein:

the UE is configured with n comb value of n (comb-n) SRS resources, indexed i=0, 1, . . . , n−1, wherein

n is an integer 4, and

each of the n resources of the n comb-n SRS resources is with a different subcarrier shift modulo (i+b, n) where b is 0, 1, . . . n−1.

15. The UE of claim 14 , wherein each of the n comb-n SRS resources of the n comb-n SRS resources has a duration of one OFDM symbol.

16. The UE of claim 14 , wherein n=4 and the four comb-4 SRS resources are of a length of one OFDM symbol and are configured to be transmitted in the same slot.

17. The UE of claim 14 , wherein n=4 and the four comb-4 SRS resources are of a length of four OFDM symbols and are configured to be transmitted in four different slots.

18. A base station comprising:

processing circuitry configured to:

transmit an SRS configuration to a user equipment, UE; and

receive, from the UE, an SRS waveform adapted for positioning based on the SRS configuration, the SRS waveform having a full bandwidth within a bandwidth configured for the SRS waveform, wherein the SRS waveform is received on every fourth subcarrier of an SRS transmission bandwidth associated with the SRS waveform, wherein a plurality of time resources for the SRS waveform comprises an SRS resource set, wherein the SRS resource set comprises four time resources, and wherein, compared to an SRS transmission in the first time resource in the SRS resource set, a frequency offset for an SRS transmission in the second time resource in the SRS resource set is 2 subcarriers, a frequency offset for an SRS transmission in the third time resource in the SRS resource set is 1 subcarrier, and a frequency offset for an SRS transmission in the fourth time resource in the SRS resource set is 3 subcarriers.

19. The base station of claim 18 , wherein the SRS waveform uses, for a comb value of n (comb-n) SRS resource, wherein n is an integer 4, every subcarrier in a combination of n Orthogonal Frequency Division Multiplexing, OFDM, symbols in all Physical Resource Blocks, PRBs, applicable for the SRS waveform.

20. The base station of claim 18 , wherein:

the UE is configured with n comb value of n (comb-n) SRS resources, indexed i=0, 1, . . . , n−1, wherein

n is an integer 4, and

each of the n resources of the n comb-n SRS resources is with a different subcarrier shift modulo (i+b, n) where b is 0, 1, . . . n−1.

21. The base station of claim 20 , wherein each of the n comb-n SRS resources of the n comb-n SRS resources has a duration of one OFDM symbol.

22. The base station of claim 20 , wherein n=4 and the four comb-4 SRS resources are of a length of one OFDM symbol and are configured to be transmitted in the same slot.

23. The base station of claim 20 , wherein n=4 and the four comb-4 SRS resources are of a length of four OFDM symbols and are configured to be transmitted in four different slots.