System and method for uplink timing synchronization in conjunction with discontinuous reception
Systems and methods for controlling sounding reference signal transmission are provided; a user equipment starts transmitting the sounding reference signal in anticipation of uplink data transmission, and then discontinues transmitting the sounding reference signal after completion of uplink data transmission.
1. A method in a user equipment (UE), the method comprising:
determining, by the UE, that the UE has uplink data to transmit;
in response to determining that the UE has uplink data to transmit, starting sounding reference signal transmissions using a set of sounding reference signal transmission resources;
transmitting an uplink resource request after starting the sounding reference signal transmissions;
transmitting the uplink data after transmitting the uplink resource request; and
in response to determining a completion of the transmission of the uplink data, stopping the sounding reference signal transmissions.
2. The method of claim 1 , the method further comprising:
operating the UE in a discontinuous reception (DRX) mode, the DRX mode causing a receiver in the UE to have on periods and off periods.
3. The method of claim 1 , wherein the set of sounding reference signal transmission resources repeat periodically.
4. The method of claim 1 , wherein the sounding reference signal transmissions start at a sounding reference signal transmission resource that is immediately prior to the uplink resource request.
5. The method of claim 1 , wherein the uplink resource request is at least one of an uplink scheduling request (SR) or a random access channel (RACH) transmission.
6. The method of claim 1 , wherein the uplink data is transmitted using hybrid automatic repeat request (HARQ) transmissions.
7. The method of claim 1 , wherein the sounding reference signal transmissions stop at a sounding reference signal transmission resource that is immediately subsequent to the completion of the transmission of the uplink data.
8. A user equipment (UE), comprising:
a memory; and
at least one hardware processor communicatively coupled with the memory and configured to:
determine that the UE has uplink data to transmit;
in response to determining that the UE has uplink data to transmit, start sounding reference signal transmissions using a set of sounding reference signal transmission resources;
transmit an uplink resource request after starting the sounding reference signal transmissions;
transmit the uplink data after transmitting the uplink resource request; and
in response to determining a completion of the transmission of the uplink data, stop the sounding reference signal transmissions.
9. The UE of claim 8 , wherein the at least one hardware processor is further configured to:
operate the UE in a discontinuous reception (DRX) mode, the DRX mode causing a receiver in the UE to have on periods and off periods.
10. The UE of claim 8 , wherein the set of sounding reference signal transmission resources repeat periodically.
11. The UE of claim 8 , wherein the sounding reference signal transmissions start at a sounding reference signal transmission resource that is immediately prior to the uplink resource request.
12. The UE of claim 8 , wherein the uplink resource request is at least one of an uplink scheduling request (SR) or a random access channel (RACH) transmission.
13. The UE of claim 8 , wherein the uplink data is transmitted using hybrid automatic repeat request (HARQ) transmissions.
14. The UE of claim 8 , wherein the sounding reference signal transmissions stop at a sounding reference signal transmission resource that is immediately subsequent to the completion of the transmission of the uplink data.
15. A non-transitory computer-readable medium containing instructions which, when executed, cause a user equipment (UE) to perform operations comprising:
determining that the UE has uplink data to transmit;
in response to determining that the UE has uplink data to transmit, starting sounding reference signal transmissions using a set of sounding reference signal transmission resources;
transmitting an uplink resource request after starting the sounding reference signal transmissions;
transmitting the uplink data after transmitting the uplink resource request; and
in response to determining a completion of the transmission of the uplink data, stopping the sounding reference signal transmissions.
16. The non-transitory computer-readable medium of claim 15 , wherein the operations further comprise:
operating the UE in a discontinuous reception (DRX) mode, the DRX mode causing a receiver in the UE to have on periods and off periods.
17. The non-transitory computer-readable medium of claim 15 , wherein the set of sounding reference signal transmission resources repeat periodically.
18. The non-transitory computer-readable medium of claim 15 , wherein the sounding reference signal transmissions start at a sounding reference signal transmission resource that is immediately prior to the uplink resource request.
19. The non-transitory computer-readable medium of claim 15 , wherein the uplink resource request is at least one of an uplink scheduling request (SR) or a random access channel (RACH) transmission.
20. The non-transitory computer-readable medium of claim 15 , wherein the sounding reference signal transmissions stop at a sounding reference signal transmission resource that is immediately subsequent to the completion of the transmission of the uplink data.