Control signaling for sounding reference signal (SRS)
Described is an apparatus of a User Equipment (UE). The apparatus may comprise a first circuitry and a second circuitry. The first circuitry may be operable to process a message carrying an indicator to indicate a selection of a Sounding Reference Signal (SRS) resource set, wherein the message is received from a gNB. The second circuitry may be operable to generate an SRS transmission, based on the indicator. The apparatus may comprise an interface to send the SRS transmission to a transmission circuitry.
1. A method of operating a user equipment (UE), the method comprising:
receiving a Sounding Reference Signal (SRS) type indicator from a base station (BS), wherein the SRS type indicator indicates an SRS resource set is used for a beam management, a non-codebook based transmission, or a codebook based transmission; and
transmitting an SRS to the BS on the SRS resource set based on the SRS type indicator.
2. The method of claim 1 , further comprising:
generating a sequence of SRS transmissions including the SRS;
transmitting the sequence of SRS transmissions to the BS; and
processing an Uplink (UL) grant that includes an SRS Resource Indicator (SRI), wherein the SRI is associated with a most recent SRS transmission of the sequence of SRS transmissions prior to receiving the SRI.
3. The method of claim 1 , wherein the SRS type indicator has one of a first value indicating a selection of a first SRS resource set or a second value indicating a selection of a second SRS resource set.
4. The method of claim 3 , wherein one or more of the first or second SRS resource sets are configured with higher layer parameters.
5. The method of claim 3 , wherein the first SRS resource set is associated with one of the SRS for the non-codebook based transmission or the SRS for the codebook based transmission.
6. The method of claim 1 , wherein the SRS type indicator comprises two bits.
7. The method of claim 1 , further comprising:
receiving, from the BS, a second indicator to indicate that no SRS resource set transmission is to be triggered; and
refraining from generating the SRS in response to the second indicator.
8. A base station configured to communicate with a user equipment (UE) on a wireless network, the base station comprising:
one or more circuitries configured to:
establish a Sounding Reference Signal (SRS) type indicator, wherein the SRS type indicator indicates an SRS resource set is used for a beam management, a non-codebook based transmission, or a codebook based transmission; and
a transceiver configured to:
transmit a message including the SRS type indicator to the UE; and
receive an SRS from the UE on the SRS resource set based on the SRS type indicator.
9. The base station of claim 8 , wherein the SRS type indicator has one of a first value indicating a selection of a first SRS resource set associated with the SRS for the non-codebook based transmission or a second value indicating a selection of a second SRS resource set associated with the SRS for the codebook based transmission.
10. The base station of claim 8 , wherein the SRS type indicator comprises two bits.
11. The base station of claim 8 , wherein:
the one or more circuitries are further configured to generate a sequence of indicators including the SRS type indicator, a second SRS type indicator, and a third SRS type indicator,
the SRS type indicator indicates a selection of a first SRS resource set for the beam management,
the second SRS type indicator indicates a selection of a second SRS resource set for the codebook based transmission, and
the third SRS type indicator indicates a selection of a third SRS resource set for the non-codebook based transmission.
12. The base station of claim 8 , wherein the SRS type indicator comprises an active SRS group index.
13. The base station of claim 12 , wherein:
the active SRS group index for a non-precoded SRS indicates the codebook based transmission, and
the active SRS group index for precoded SRS indicates the non-codebook-based transmission.
14. A method for operating a base station, the method comprising:
establishing a Sounding Reference Signal (SRS) type indicator, wherein the SRS type indicator indicates an SRS resource set is used for a beam management, a non-codebook based transmission, or a codebook based transmission;
transmitting a message including the SRS type indicator to a user equipment (UE); and
receiving an SRS from the UE on the SRS resource set based on the SRS type indicator.
15. The method of claim 14 , wherein the SRS type indicator has one of a first value indicating a selection of a first SRS resource set associated with the SRS for the non-codebook based transmission or a second value indicating a selection of a second SRS resource set associated with the SRS for the codebook based transmission.
16. The method of claim 14 , further comprising:
generating a sequence of indicators including the SRS type indicator, a second SRS type indicator, and a third SRS type indicator; and
transmitting the sequence of indicators,
wherein the SRS type indicator indicates a selection of a first SRS resource set for the beam management,
wherein the second SRS type indicator indicates a selection of a second SRS resource set for the codebook based transmission, and
wherein the third SRS type indicator indicates a selection of a third SRS resource set for the non-codebook based transmission.
17. The method of claim 14 , wherein the SRS type indicator comprises an active SRS group index.
18. The method of claim 17 , wherein:
the active SRS group index for a non-precoded SRS indicates the codebook based transmission, and
the active SRS group index for a precoded SRS indicates the non-codebook based transmission.
19. The method of claim 14 , further comprising:
transmitting an Uplink (UL) grant to the UE based on the SRS type indicator of a latest successfully received SRS.
20. The method of claim 14 , wherein the message comprises higher layer signaling.