UE, filtering method thereof and computer-readable recording medium

1. A user equipment (UE), comprising:

an estimation circuit configured to:

estimate a channel for a sub-frame from a cell-specific reference signal;

estimate interference for the sub-frame from the cell-specific reference signal;

a determination circuit configured to determine the sub-frame is a flexible sub-frame, the flexible sub-frame being configured for transmission of different directions for a serving cell and a neighboring cell respectively;

a filtering circuit configured to filter the estimated channel for the flexible sub-frame with a first filtering function having at least one parameter for the channel different from that for a normal sub-frame, the normal sub-frame being configured for transmission of same directions for the serving cell and the neighboring cell.

2. The UE of claim 1 , wherein the at least one parameter for the channel includes a forgetting factor α H , and the first filtering function satisfies the following equation

H ( n )=(1−α H )· H ( n− 1)+α H ·H ( n ),

wherein H(n) and H (n) denote the estimated channel and the filtered estimated channel for the n th DL sub-frame, respectively; n denotes a sequential number of the sub-frame; and α H is different for the normal sub-frame and the flexible sub-frame.

3. The UE of claim 1 , wherein the first filtering function is implemented by a single filter with different parameters for the flexible sub-frame and the normal sub-frame, or is implemented by two filters with different parameters for the flexible sub-frame and the normal sub-frame separately.

4. The UE of claim 1 , wherein the sub-frame is determined to be the flexible sub-frame if the UE detects any difference in frame configurations based on a Time Division Duplex configuration signaling received from both the serving cell and the neighboring cell.

5. The UE of claim 1 , wherein the filtering circuit is further configured to filter the estimated interference for the flexible sub-frame with a second filtering function having at least one parameter for the interference different from that for the normal sub-frame.

6. The UE of claim 5 , wherein the at least one parameter for the interference includes a forgetting factor α I , and the filtering function satisfies the following equation

I ( n )=(1−α I )· I ( n− 1)+α I ·I ( n ),

wherein I(n) and Ī(n) denote the estimated interference and the filtered estimated interference for a n th sub-frame, respectively; n denotes a sequential number of the sub-frame; and α I is different for the normal sub-frame and the flexible sub-frame.

7. The UE of claim 5 , wherein the second filtering function is implemented by a single filter with different parameters for the flexible sub-frame and the normal sub-frame, or is implemented by two filters with different parameters for the flexible sub-frame and the normal sub-frame separately.

8. The UE of claim 5 , wherein the sub-frame is determined to be the flexible sub-frame if a difference between the estimated interference for the sub-frame and the filtered estimated interference for a previous sub-frame is higher than a predefined threshold.

9. A filtering method in a user equipment (UE), the method comprising:

estimating a channel for a sub-frame from a cell-specific reference signal;

estimating interference for the sub-frame from the cell-specific reference signal;

determining the sub-frame is a flexible sub-frame, the flexible sub-frame being configured for transmission of different directions for a serving cell and a neighboring cell respectively;

filtering the estimated channel for the flexible sub-frame with a first filtering function having at least one parameter for the channel different from that for a normal sub-frame, the normal sub-frame being configured for transmission of same directions for the serving cell and the neighboring cell.

10. The method of claim 9 , wherein the at least one parameter for the channel includes a forgetting factor α H , and the first filtering function satisfies the following equation

H ( n )=(1−α H )· H ( n− 1)+α H ·H ( n ),

wherein H(n) and H (n) denote the estimated channel and the filtered estimated channel for the n th DL sub-frame, respectively; n denotes a sequential number of the sub-frame; and α H is different for the normal sub-frame and the flexible sub-frame.

11. The method of claim 9 , wherein the first filtering function is implemented by a single filter with different parameters for the flexible sub-frame and the normal sub-frame, or is implemented by two filters with different parameters for the flexible sub-frame and the normal sub-frame separately.

12. The method of claim 9 , wherein the sub-frame is determined to be the flexible sub-frame if the UE detects any difference in frame configurations based on a Time Division Duplex configuration signaling received from both the serving cell and the neighboring cell.

13. The method of claim 9 , further comprising filtering the estimated interference for the flexible sub-frame with a second filtering function having at least one parameter for the interference different from that for the normal sub-frame.

14. The method of claim 13 , wherein the at least one parameter for the interference includes a forgetting factor α I , and the filtering function satisfies the following equation

I ( n )=(1−α I )· I ( n− 1)+α I ·I ( n ),

wherein I(n) and Ī(n) denote the estimated interference and the filtered estimated interference for a n th sub-frame, respectively; n denotes a sequential number of the sub-frame; and α I is different for the normal sub-frame and the flexible sub-frame.

15. The method of claim 13 , wherein the second filtering function is implemented by a single filter with different parameters for the flexible sub-frame and the normal sub-frame, or is implemented by two filters with different parameters for the flexible sub-frame and the normal sub-frame separately.

16. The method of claim 13 , wherein the sub-frame is determined to be the flexible sub-frame if a difference between the estimated interference for the sub-frame and the filtered estimated interference for a previous sub-frame is higher than a predefined threshold.

17. A computer program product stored in a non-transitory computer program product for controlling a procedure for filtering interference in a user equipment (UE), the computer program product comprising software instructions which, when run on one or more processing circuits of the UE, causes the UE to perform a procedure comprising:

estimating a channel for a sub-frame from a cell-specific reference signal;

estimating interference for the sub-frame from the cell-specific reference signal;

determining the sub-frame is a flexible sub-frame, the flexible sub-frame being configured for transmission of different directions for a serving cell and a neighboring cell respectively;

filtering the estimated channel for the flexible sub-frame with a first filtering function having at least one parameter for the channel different from that for a normal sub-frame, the normal sub-frame being configured for transmission of same directions for the serving cell and the neighboring cell.

18. The computer program product of claim 17 , wherein the at least one parameter for the channel includes a forgetting factor α H , and the first filtering function satisfies the following equation

H ( n )=(1−α H )· H ( n− 1)+α H ·H ( n ),

wherein H(n) and H (n) denote the estimated channel and the filtered estimated channel for the n th DL sub-frame, respectively; n denotes a sequential number of the sub-frame; and α H is different for the normal sub-frame and the flexible sub-frame.

19. The computer program product of claim 17 , wherein the first filtering function is implemented by a single filter with different parameters for the flexible sub-frame and the normal sub-frame, or is implemented by two filters with different parameters for the flexible sub-frame and the normal sub-frame separately.

20. The computer program product of claim 17 , wherein the sub-frame is determined to be the flexible sub-frame if the UE detects any difference in frame configurations based on a Time Division Duplex configuration signaling received from both the serving cell and the neighboring cell.

21. The computer program product of claim 17 , wherein the procedure further comprises filtering the estimated interference for the flexible sub-frame with a second filtering function having at least one parameter for the interference different from that for the normal sub-frame.

22. The computer program product of claim 21 , wherein the at least one parameter for the interference includes a forgetting factor α I , and the filtering function satisfies the following equation

I ( n )=(1−α I )· I ( n− 1)+α I ·I ( n ),

wherein I(n) and Ī(n) denote the estimated interference and the filtered estimated interference for a n th sub-frame, respectively; n denotes a sequential number of the sub-frame; and α I is different for the normal sub-frame and the flexible sub-frame.

23. The computer program product of claim 21 , wherein the second filtering function is implemented by a single filter with different parameters for the flexible sub-frame and the normal sub-frame, or is implemented by two filters with different parameters for the flexible sub-frame and the normal sub-frame separately.

24. The computer program product of claim 21 , wherein the sub-frame is determined to be the flexible sub-frame if a difference between the estimated interference for the sub-frame and the filtered estimated interference for a previous sub-frame is higher than a predefined threshold.