Method of UE RSRQ measurement precaution for interference coordination
A method of UE RSRQ measurement precaution for interference coordination is provided. The UE receives radio signals of a neighbor cell under measurement. The neighbor cell applies a TDM silencing pattern for inter-cell interference coordination (TDM ICIC). The UE determines a measurement pattern that includes multiple subframes. The UE performs RSRQ measurements of the cell over multiple subframes and obtains multiple RSRQ measurement samples. The UE derives RSRQ measurement result by estimating the multiple RSRQ samples and applying a weighted average. RSRQ samples estimated to be more applicable are taken into account to more extent (e.g., applied with more weight), and/or RSRQ samples estimated to be less applicable are taken into account to less extent (e.g., applied with less weight, or discarded with zero weight). With UE precaution, a more predictable RSRQ measurement result is produced.
1. A method comprising:
(a) receiving radio signals of a cell under measurement by a user equipment (UE) in a wireless communication system, wherein a neighbor cell applies a TDM silencing pattern for inter-cell interference coordination (ICIC);
(b) performing reference signal received quality (RSRQ) measurements of the measured cell over multiple subframes and thereby obtaining multiple RSRQ measurement samples; and
(c) deriving a final RSRQ measurement result by estimating the multiple RSRQ measurement samples of the multiple subframes in the same measured cell and applying a weighted average, wherein the estimation involves correlating the RSRQ samples of the multiple subframes in the same measured cell with a presumed TDM silencing pattern.
2. The method of claim 1 , wherein the TDM silencing pattern includes normal subframes and silenced subframes.
3. The method of claim 2 , wherein the measured cell is the neighbor cell, wherein RSRQ samples with lower received signal strength indicator (RSSI) are given less weights than RSRQ samples with higher RSSI.
4. The method of claim 2 , wherein the measured cell is a victim cell, wherein RSRQ samples with lower received signal strength indicator (RSSI) are given more weights than RSRQ samples with higher RSSI.
5. The method of claim 1 , wherein RSRQ samples in a silenced subframe are given a less weight than RSRQ samples in a normal subframe in deriving the RSRQ measurement result, when the measured cell performs silencing.
6. The method of claim 1 , wherein RSRQ samples in a silenced subframe are given a more weight than RSRQ samples in a normal subframe in deriving the RSRQ measurement result, when the measured cell is a victim cell.
7. The method of claim 1 , wherein the pre-assumed TDM silencing pattern is based on knowledge of subframes used to transmit broadcasting control information in the measured cell.
8. The method of claim 1 , wherein the pre-assumed TDM silencing pattern is obtained from TDM silence patterns in other neighbor cells.
9. The method of claim 1 , wherein the RSRQ samples estimated to be less applicable are discarded in deriving the RSRQ measurement result.
10. The method of claim 1 , wherein the UE identifies whether the measured cell is an aggressor cell or a victim cell via signaling.
11. A user equipment (UE), comprising:
a radio frequency module that receives radio signals of a neighbor cell in a wireless communication system, wherein the neighbor cell applies a TDM silencing pattern for inter-cell interference coordination (ICIC); and
a measurement module that performs reference signal received quality (RSRQ) measurements over multiple subframes and thereby obtaining multiple RSRQ measurement samples, wherein the measurement module also determines RSRQ measurement result by estimating the RSRQ samples of the multiple subframes in the same measured cell, wherein the estimating involves correlating the RSRQ samples of the multiple subframes in the same measured cell with a fixed pre-assumed TDM silencing pattern.
12. The UE of claim 11 , wherein the TDM silencing pattern includes normal subframes and silenced subframes.
13. The UE of claim 12 , wherein the measured cell is the neighbor cell, wherein RSRQ samples with lower received signal strength indicator (RSSI) are given less weights than RSRQ samples with higher RSSI.
14. The UE of claim 12 , wherein the measured cell is a victim cell, wherein RSRQ samples with lower received signal strength indicator (RSSI) are given more weights than RSRQ samples with higher RSSI.
15. The UE of claim 11 , wherein RSRQ samples in a silenced subframe are given a less weight than RSRQ samples in a normal subframe in determining the RSRQ measurement result, when measuring a cell performs silencing.
16. The UE of claim 11 , wherein RSRQ samples in a silenced subframe are given a more weight than RSRQ samples in a normal subframe in determining the RSRQ measurement result, when measuring a victim cell.
17. The UE of claim 16 , wherein the pre-assumed TDM silencing pattern is based on knowledge of subframes used to transmit broadcasting control information in the victim cell.
18. The UE of claim 17 , wherein the broadcasting control information is transmitted via a broadcasting channel (BCH), a master information block or system information block (MIB/SIB), and a paging channel (PCH).
19. The UE of claim 11 , wherein the pre-assumed TDM silencing pattern is obtained from TDM silence patterns in other neighbor cells.
20. The UE of claim 11 , wherein the measurement module performs RSRQ measurements over a minimum number of consecutive subframes.