System and method for uplink timing synchronization in conjunction with discontinuous reception
A system and method are disclosed for providing uplink timing synchronization during DRX operation in a wireless communication system.
1. A method in a user equipment comprising:
controlling a receiver to monitor a control channel during a discontinuous reception (DRX) active time;
stopping from transmitting an uplink sounding reference signal (SRS) responsive to said DRX active time ending; and
maintaining an SRS resource configuration for the user equipment after said DRX active time ends, wherein the SRS resource configuration is associated with a time-frequency resource; and
restarting transmission of SRS responsive to said DRX active time restarting.
2. The method of claim 1 , wherein the maintained SRS resource configuration for the user equipment is used for the transmission of the SRS responsive to said DRX active time restarting.
3. The method of claim 1 further comprising releasing the SRS resource configuration for the user equipment at the expiration of a time alignment timer.
4. The method of claim 1 further comprising determining the SRS resource configuration for the user equipment based on an SRS configuration element received from a network access device.
5. The method of claim 1 further comprising entering a reduced power state when not in said DRX active time.
6. The method of claim 1 further comprising not monitoring the control channel when not in said DRX active time.
7. The method of claim 1 further comprising transmitting the uplink SRS during the active time using the SRS resource configuration.
8. The method of claim 1 further comprising determining an SRS repetition period based on an SRS configuration element received from a network access device.
9. The method of claim 1 , wherein said DRX active time is associated with DRX operation in a connected mode.
10. The method of claim 1 , wherein the DRX active time includes at least a time period corresponding to an on duration and a time period when an inactivity timer is running.
11. A user equipment (UE) comprising:
a receiver, the receiver configured to monitor a control channel during a discontinuous reception (DRX) active time; and
a controller, the controller configured to:
stop transmission of an uplink sounding reference signal (SRS) responsive to said DRX active time ending, and
maintain an SRS resource configuration for the user equipment after said DRX active time ends, wherein the SRS resource configuration is associated with a time-frequency resource; and
restart transmission of SRS in response to said DRX active time restarting.
12. The UE of claim 11 , wherein the maintained SRS resource configuration for the user equipment is used for the transmission of the SRS responsive to said DRX active time restarting.
13. The UE of claim 11 wherein the controller is further configured to release the SRS resource configuration for the user equipment at the expiration of a time alignment timer.
14. The UE of claim 11 wherein the controller is further configured to determine the SRS resource configuration for the user equipment based on an SRS configuration element received from a network access device.
15. The UE of claim 11 wherein the controller is further configured to enter a reduced power state when not in said DRX active time.
16. The UE of claim 11 wherein the controller is further configured to not monitor the control channel when not in said DRX active time.
17. The UE of claim 11 wherein the controller is further configured to transmit the uplink SRS during the active time using the SRS resource configuration.
18. The UE of claim 11 wherein the controller is further configured to determine an SRS repetition period based on an SRS configuration element received from a network access device.
19. The UE of claim 11 , wherein said DRX active time is a connected mode DRX active time.
20. The UE of claim 11 , wherein the DRX active time includes at least a time period corresponding to an on duration and a time period when an inactivity timer is running.
21. A network access equipment comprising a processor configured to:
send control information to a user equipment comprising a receiver, the control information to configure the user equipment to control the receiver to have discontinuous reception (DRX) active time;
send control information to the user equipment indicative of uplink sounding reference signal (SRS) sub-frames based on an SRS repetition period;
stop receiving an uplink sounding reference signal (SRS) from the user equipment responsive to said DRX active time ending; and
maintain an SRS resource configuration for the user equipment after said DRX active time ends, wherein the SRS resource configuration is associated with a time-frequency resource; and
restart receiving of SRS responsive to said DRX active time restarting.
22. The network access equipment of claim 21 , wherein the maintained SRS resource configuration for the user equipment is used for the transmission of the SRS responsive to said DRX active time restarting.
23. The network access equipment of claim 21 , wherein said DRX active time is a connected mode DRX active time.
24. The network access equipment of claim 21 , wherein the DRX active time includes at least a time period corresponding to an on duration and a time period when an inactivity timer is running.
25. A non-transitory machine-readable medium with a set of instructions stored thereon, which when executed, cause a processor to perform operations comprising:
controlling a receiver to monitor a control channel during a discontinuous reception (DRX) active time;
stopping from transmitting an uplink sounding reference signal (SRS) responsive to said DRX active time ending;
maintaining an SRS resource configuration for a user equipment when not in said DRX active time, wherein the SRS resource configuration is associated with a time-frequency resource; and
restarting transmission of the SRS responsive to said DRX active time restarting.
26. The non-transitory machine-readable medium of claim 25 , wherein the maintained SRS resource configuration for the user equipment is used for the transmission of the SRS responsive to said DRX active time restarting.
27. The non-transitory machine-readable medium of claim 25 , wherein the operations further comprise releasing the SRS resource configuration for the user equipment at the expiration of a time alignment timer.
28. The non-transitory machine-readable medium of claim 25 , wherein the operations further comprise entering a reduced power state when not in said DRX active time.
29. The non-transitory machine-readable medium of claim 25 , wherein the operations further comprise transmitting the uplink SRS during the active time using the SRS resource configuration.
30. The non-transitory machine-readable medium of claim 25 , wherein said DRX active time is associated with DRX operation in a connected mode.
31. The non-transitory machine-readable medium of claim 25 , wherein the DRX active time includes at least a time period corresponding to an on duration and a time period when an inactivity timer is running.
32. A method performed in a network access equipment comprising:
sending control information to a user equipment comprising a receiver, the control information to configure the user equipment to control the receiver to have discontinuous reception (DRX) active time;
sending control information to the user equipment indicative of uplink sounding reference signal (SRS) sub-frames based on an SRS repetition period;
stopping from receiving an uplink sounding reference signal (SRS) from the user equipment responsive to said DRX active time ending;
maintaining an SRS resource configuration for the user equipment after said DRX active time ends, wherein the SRS resource configuration is associated with a time-frequency resource; and
restart receiving of SRS responsive to said DRX active time restarting.
33. The method of claim 32 , wherein the maintained SRS resource configuration for the user equipment is used for the transmission of the SRS responsive to said DRX active time restarting.
34. The method of claim 32 , wherein said DRX active time is a connected mode DRX active time.
35. The method of claim 32 , wherein the DRX active time includes at least a time period corresponding to an on duration and a time period when an inactivity timer is running.