SRS signaling in 5G new radio wireless communications
A base station is configured to determine a sounding reference signal (SRS) configuration that has a plurality of cyclic shifts for a comb 8 SRS, a plurality of user equipment (UE) ports for transmitting the comb 8 SRS and a mapping of the plurality of cyclic shifts to the plurality of UE ports. The base station is further configured to transmit the SRS configuration to the UE.
1. A processor of a base station configured to perform operations comprising:
determining a sounding reference signal (SRS) configuration, comprising:
a plurality of cyclic shifts for a comb 8 SRS;
a plurality of user equipment (UE) ports for transmitting the comb 8 SRS; and
a mapping of the plurality of cyclic shifts to the plurality of UE ports, when an SRS sequence length is an integer multiple of 6, the maximum number of the plurality of cyclic shifts is six cyclic shifts; and
generating, for transmission to the UE, the SRS configuration.
2. The processor of claim 1 , wherein the maximum number of the plurality of cyclic shifts is based on an SRS sequence length.
3. The processor of claim 2 , wherein, when the SRS sequence length is an integer multiple of 6 but not an integer multiple of 8 or 12, a maximum number of the plurality of UE ports is two ports.
4. The processor of claim 2 , wherein, when the SRS sequence length is an integer multiple of 8 but not an integer multiple of 12, the maximum number of the plurality of cyclic shifts is eight cyclic shifts and a maximum number of the plurality of UE ports is four ports.
5. The processor of claim 2 , wherein, when the SRS sequence length is an integer multiple of 12, the maximum number of the plurality of cyclic shifts is twelve cyclic shifts and a maximum number of the plurality of UE ports is four ports.
6. The processor of claim 1 , wherein a maximum number of the plurality of UE ports is six ports.
7. The processor of claim 1 , wherein mapping the six cyclic shifts to the plurality of ports includes configuring a phase ramping value of
i
3
π
for each port, where i is a corresponding one of the six cyclic shifts.
8. The processor of claim 1 , wherein a minimum subband size of the comb 8 SRS is eight physical resource blocks (PRBs).
9. The processor of claim 1 , wherein the maximum number of the plurality of ports is four ports, the mapping includes configuring, for each of the four ports, a phase ramping value of
a
i
=
2
π
n
SRS
cs
,
i
n
SRS
cs
,
max
,
where
n
SRS
cs
,
i
=
(
n
SRS
cs
+
(
p
i
-
1000
)
)
mod
n
SRS
cs
,
max
where α i is a phase ramp for SRS port i, n SRS cs,max is a maximum number of cyclic shifts, n SRS cs is a configured one of the six cyclic shifts, and p i is a port index for SRS port i.
10. A base station, comprising:
a transceiver configured to communicate with a user equipment (UE); and
a processor communicatively coupled to the transceiver and configured to perform operations comprising:
determining a sounding reference signal (SRS) configuration, comprising:
a plurality of cyclic shifts for a comb 8 SRS;
a plurality of user equipment (UE) ports for transmitting the comb 8 SRS; and
a mapping of the plurality of cyclic shifts to the plurality of UE ports, when an SRS sequence length is an integer multiple of 6, the maximum number of the plurality of cyclic shifts is six cyclic shifts; and
transmitting the SRS configuration to the UE.
11. The base station of claim 10 , wherein the maximum number of the plurality of cyclic shifts is based on an SRS sequence length.
12. The base station of claim 11 , wherein, when the SRS sequence length is an integer multiple of 6 but not an integer multiple of 8 or 12, a maximum number of the plurality of UE ports is two ports.
13. The base station of claim 11 , wherein, when the SRS sequence length is an integer multiple of 8 but not an integer multiple of 12, the maximum number of the plurality of cyclic shifts is eight cyclic shifts and a maximum number of the plurality of UE ports is four ports.
14. The base station of claim 11 , wherein, when the SRS sequence length is an integer multiple of 12, the maximum number of the plurality of cyclic shifts is twelve cyclic shifts and a maximum number of the plurality of UE ports is four ports.
15. The base station of claim 10 , wherein a maximum number of the plurality of UE ports is six ports.
16. The base station of claim 10 , wherein mapping the six cyclic shifts to the plurality of ports includes configuring a phase ramping value of
i
3
π
for each port, where i is a corresponding one of the six cyclic shifts.
17. The base station of claim 10 , wherein a minimum subband size of the comb 8 SRS is eight physical resource blocks (PRBs) and a maximum number of the plurality of ports is four ports.
18. The base station of claim 10 , wherein the maximum number of the plurality of ports is four ports, the mapping includes configuring, for each of the four ports, a phase ramping value of
a
i
=
2
π
n
SRS
cs
,
i
n
SRS
cs
,
max
,
where
n
SRS
cs
,
i
=
(
n
SRS
cs
+
(
p
i
-
1000
)
)
mod
n
SRS
cs
,
max
where α i is a phase ramp for SRS port i, n SRS cs,max is a maximum number of cyclic shifts, n SRS cs is a configured one of the six cyclic shifts, and p i is a port index for SRS port i.