Method and apparatus for low-latency beam selection

1. A user equipment (UE) comprising:

a transceiver configured to receive configuration information on a set of uplink (UL) beams and at least one associated sounding reference signal (SRS) resource; and

a processor operably connected to the transceiver, the processor configured to:

detect that an event occurs, and

calculate an UL beam reporting associated with at least one of the UL beams,

wherein the transceiver is further configured to:

initiate or receive a request for an SRS transmission, and

transmit the UL beam reporting after the event occurs.

2. The UE of claim 1 , wherein the transceiver is configured to transmit the SRS transmission on one of the at least one associated SRS resource after the event occurs and in response to reception of the request for the SRS transmission.

3. The UE of claim 1 , wherein to initiate the SRS transmission, the transceiver is configured to:

transmit a pre-notification message indicating the SRS transmission after the event occurs; and

transmit the SRS transmission on one of the at least one associated SRS resource after transmission of the pre-notification message.

4. The UE of claim 3 , wherein:

to detect that the event occurs, the processor is configured to determine that at least one of a reference signal receive power (RSRP) value and a signal to noise ratio (SINR) value measured from at least one downlink reference signal (DL RS) is smaller than a threshold, and

the pre-notification message is transmitted in response to detection that the event occurs.

5. The UE of claim 1 , wherein the transceiver is further configured to transmit an UL beam recommendation in the UL beam reporting after the event occurs.

6. The UE of claim 1 , wherein the transceiver is further configured to:

transmit a pre-notification message indicating transmission of an UL beam recommendation after the event occurs; and

transmit the UL beam recommendation in the UL beam reporting after transmission of the pre-notification message.

7. The UE of claim 6 , wherein:

to detect that the event occurs, the processor is configured to determine that at least one of a reference signal receive power (RSRP) value and a signal to noise ratio (SINR) value measured from at least one downlink reference signal (DL RS) is smaller than a threshold, and

the pre-notification message is transmitted in response to detection that the event occurs.

8. A base station (BS) comprising:

a processor configured to:

generate configuration information on a set of uplink (UL) beams and at least one associated sounding reference signal (SRS) resource; and

a transceiver operably connected to the processor, the transceiver configured to:

transmit the configuration information for the UL beams and the at least one associated SRS resource;

receive or transmit a request for an SRS transmission; and

receive an UL beam reporting associated with at least one of the UL beams after an event occurs.

9. The BS of claim 8 , wherein the transceiver is configured to receive the SRS transmission on one of the at least one associated SRS resource after the event occurs and in response to transmission of the request for the SRS transmission.

10. The BS of claim 8 wherein the transceiver is configured to:

receive a pre-notification message indicating the SRS transmission after the event occurs; and

receive the SRS transmission on one of the at least one associated SRS resource after reception of the pre-notification message.

11. The BS of claim 10 , wherein the event includes at least one of a reference signal receive power (RSRP) value and a signal to noise ratio (SINR) value measured from at least one downlink reference signal (DL RS) being smaller than a threshold.

12. The BS of claim 8 , wherein the transceiver is further configured to receive an UL beam recommendation in the UL beam reporting after the event occurs.

13. The BS of claim 8 , wherein the transceiver is further configured to:

receive a pre-notification message indicating transmission of an UL beam recommendation after the event occurs; and

receive the UL beam recommendation in the UL beam reporting after reception of the pre-notification message.

14. A method for operating a user equipment (UE), the method comprising:

receiving configuration information on a set of uplink (UL) beams and at least one associated sounding reference signal (SRS) resource;

detecting that an event occurs;

calculating an UL beam reporting associated with at least one of the UL beams;

initiating or receiving a request for an SRS transmission; and

transmitting the UL beam reporting after the event occurs.

15. The method of claim 14 , further comprising transmitting the SRS transmission on one of the at least one associated SRS resource after the event occurs.

16. The method of claim 14 , wherein initiating or receiving the request for the SRS transmission comprises initiating the SRS transmission by:

transmitting a pre-notification message indicating the SRS transmission after the event occurs; and

transmitting the SRS transmission on one of the at least one associated SRS resource after transmission of the pre-notification message.

17. The method of claim 16 , wherein:

detecting that the event occurs comprises determining that at least one of a reference signal receive power (RSRP) value and a signal to noise ratio (SINR) value measured from at least one downlink reference signal (DL RS) is smaller than a threshold, and

the pre-notification message is transmitted in response to detection that the event occurs.

18. The method of claim 14 , wherein transmitting the UL beam reporting comprises transmitting an UL beam recommendation in the UL beam reporting after the event occurs.

19. The method of claim 14 , further comprising:

transmitting a pre-notification message indicating transmission of an UL beam recommendation after the event occurs,

wherein transmitting the UL beam reporting comprises transmitting the UL beam recommendation in the UL beam reporting after transmitting the pre-notification message.

20. The method of claim 19 , wherein:

detecting that the event occurs comprises determining that at least one of a reference signal receive power (RSRP) value and a signal to noise ratio (SINR) value measured from at least one downlink reference signal (DL RS) is smaller than a threshold, and

the pre-notification message is transmitted in response to detection that the event occurs.