Synchronization detection using bandwidth and antenna configuration
View Patent ↗User Equipment in a wireless communication network considers the downlink channel bandwidth in setting out of synchronization (OoS) and in synchronization (IS) thresholds and filter durations. Additionally, the UE may consider transmitter antenna configuration—that is, the number of transmitting antennas in a MIMO system—in setting the OoS and IS thresholds. The UE determines it is OoS when a monitored, filtered, downlink channel quality metric, such as reference symbol SINR, is below the OoS threshold.
1. A method of determining synchronization of a User Equipment (UE) in a wireless communication network, comprising:
determining a downlink cell transmission bandwidth (BW);
setting an Out of Synchronization (OoS) threshold based on the downlink BW;
monitoring at least one metric of downlink communication channel quality;
comparing the channel quality metric to the OoS threshold; and
if the channel quality metric is below the OoS threshold, determining that the UE is out of synchronization with the network.
2. The method of claim 1 wherein monitoring at least one metric of downlink communication channel quality comprises averaging the value of the channel quality metric over a duration determined in response to the downlink BW.
3. The method of claim 1 further comprising determining an antenna configuration at a wireless communication network transmitter, and wherein setting an OoS threshold based on the downlink BW comprises setting an OoS threshold based on the downlink BW and the transmitter antenna configuration.
4. The method of claim 1 further comprising, after determining the UE is OoS:
monitoring at least one metric of downlink communication channel quality; and
if the channel quality metric exceeds an In Synchronization (IS) threshold, determining that the UE is in synchronization with the network.
5. The method of claim 4 wherein the IS threshold is the same as the OoS threshold.
6. The method of claim 4 wherein the IS threshold is different than the OoS threshold.
7. The method of claim 6 wherein the IS threshold is less than the OoS threshold.
8. The method of claim 6 wherein the IS threshold is determined in response to the downlink BW.
9. The method of claim 8 wherein the IS threshold is determined in response to the downlink BW and an antenna configuration at a wireless communication network transmitter.
10. A User Equipment (UE) operative in a wireless communication network, the UE comprising:
a receiver;
a controller operative to control the receiver, and further operative to
determine a cell transmission bandwidth (BW);
set an Out of Synchronization (OoS) threshold based on the downlink BW;
monitor at least one metric of downlink communication channel quality;
compare the channel quality metric to the OoS threshold; and
if the channel quality metric is below the OoS threshold, determine that the UE is out of synchronization with the network.
11. The method of claim 10 wherein the controller is operative to monitor at least one metric of downlink communication channel quality by averaging the value of the channel quality metric over a duration determined in response to the downlink BW.
12. The UE of claim 10 wherein the controller is further operative to determine an antenna configuration at a wireless communication network transmitter, and wherein setting an OoS threshold based on the downlink BW comprises setting an OoS threshold based on the downlink BW and the transmitter antenna configuration.
13. The UE of claim 10 wherein, after determining the UE is OoS, the controller is further operative to:
monitor at least one metric of downlink communication channel quality; and
if the channel quality metric exceeds an In Synchronization (IS) threshold, determine that the UE is in synchronization with the network.
14. The UE of claim 13 wherein the IS threshold is the same as the OoS threshold.
15. The UE of claim 13 wherein the IS threshold is different than the OoS threshold.
16. The UE of claim 15 wherein the controller determines the IS threshold in response to the downlink BW.
17. The UE of claim 16 wherein the controller determines the IS threshold in response to the downlink BW and an antenna configuration at a wireless communication network transmitter.