System and method for uplink timing synchronization in conjunction with discontinuous reception
View Patent ↗A system and method are disclosed for providing uplink timing synchronization during DRX operation in a wire-less communication system.
1. A method of uplink sounding reference signal transmission in a user equipment (UE), comprising:
controlling a receiver in the UE to have a discontinuous reception (DRX) operation active time;
determining uplink sounding reference signal (SRS) subframes based on an SRS repetition period;
refraining from transmitting uplink SRS on the determined SRS subframes when not in DRX active time; and
maintaining an SRS resource allocated for the UE when not in DRX active time, wherein the SRS resource is a time-frequency resource.
2. The method of claim 1 , wherein the SRS resource allocated for the UE is released at the expiration of a time alignment timer.
3. The method of claim 1 , further comprising refraining from transmitting channel quality indictor (CQI) transmissions when not in active time.
4. The method of claim 1 , further comprising:
using a transmission resource to transmit an uplink timing reference signal transmission; and
maintaining the transmission resource during both active time and non-active time.
5. The method of claim 1 , further comprising transmitting channel quality indictor (CQI) transmissions and an uplink timing reference signal transmission in a same sub-frame during an active time.
6. The method of claim 1 , wherein the DRX active time is a connected mode DRX active time.
7. A user equipment (UE), comprising:
a processor configured to control a receiver in the UE to have a discontinuous reception (DRX) operation active time;
the processor further configured to determine uplink sounding reference signal (SRS) subframes based on an SRS repetition period;
the processor further configured to refrain from transmitting uplink SRS on the determined SRS subframes when not in DRX active time; and
the processor further configured to maintain an SRS resource allocated for the when not in DRX active time, wherein the SRS resource is a time-frequency resource.
8. The UE of claim 7 , wherein the SRS resource allocated for the UE is released at the expiration of a time alignment timer.
9. The UE of claim 7 , wherein the processor is further configured to refrain from transmitting channel quality indictor (CQI) transmissions when not in active time.
10. The UE of claim 7 , wherein the processor is further configured to use a transmission resource to transmit an uplink timing reference signal transmission and to maintain the transmission resource during both active time and non-active time.
11. The UE of claim 7 , wherein the processor is further configured to transmit channel quality indictor (CQI) transmissions and an uplink timing reference signal transmission in a same sub-frame during an active time.
12. The UE of claim 7 , wherein the DRX active time is a connected mode DRX active time.