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 network access equipment, comprising:
transmitting a timing alignment update command for adjusting an uplink timing alignment of a user device;
resetting a timing alignment timer in response to transmitting the timing alignment update command;
configuring a discontinuous reception (DRX) mode for the user device;
configuring a sounding reference signal (SRS) resource for the user device;
receiving an SRS: (1) during DRX active time, or (2) irrespective of the DRX active time when the SRS resource is used;
releasing a resource configuration for the user device to transmit the SRS upon expiration of the time alignment timer; and
maintaining the resource configuration for the user device to transmit the SRS when not in the DRX active time.
2. The method of claim 1 , further comprising sending an instruction to the user device to activate the SRS transmission.
3. The method of claim 1 , wherein the DRX cycle is determined based on a level of communication activity of the user device.
4. The method of claim 1 , further comprising determining a SRS repetition period for the user device to transmit the SRS.
5. The method of claim 1 , further comprising transmitting a SRS configuration element to the user device, the SRS configuration element including the resource configuration for the UE to transmit the SRS.
6. The method of claim 1 , further comprising releasing a resource configuration for the user device to transmit channel quality indictor (CQI) upon expiration of the time alignment timer.
7. The method of claim 1 , further comprising determining a DRX cycle for the user device.
8. A network access equipment for a wireless telecommunications system, comprising:
a transmitter configured to transmit a timing alignment update command for adjusting an uplink timing alignment of a user device;
a receiver; and
a processor, the processor configured to perform operations comprising:
resetting a timing alignment timer in response to transmitting the timing alignment update command;
configuring a discontinuous reception (DRX) mode for the user device;
configuring a sounding reference signal (SRS) mode for the user device;
controlling the receiver to receive an SRS: (1) during DRX active time, or (2) irrespective of the DRX active time when the SRS resource is used;
releasing a resource configuration for the user device to transmit the SRS upon expiration of the time alignment timer; and
maintaining the resource configuration for the user device to transmit the SRS when not in the DRX active time.
9. The network access equipment of claim 8 , wherein the processor is further configured to control a transmitter to send an instruction to the user device to activate the SRS transmission.
10. The network access equipment of claim 8 , wherein the DRX cycle is determined based on a level of communication activity of the user device.
11. The network access equipment of claim 8 , wherein the processor is further configured to determine a SRS repetition period for the user device to transmit the SRS.
12. The network access equipment of claim 8 , wherein the processor is further configured to controlling a transmitter to transmit a SRS configuration element to the user device, the SRS configuration element including the resource configuration for the user device to transmit the SRS.
13. The network access equipment of claim 8 , wherein the processor is further configured to release a resource configuration for the user device to transmit channel quality indictor (CQI) upon expiration of the time alignment timer.
14. The network access equipment of claim 8 , wherein the processor is further configured to determine a DRX cycle for the user device.