Methods and apparatus for signal and interference energy estimation in a communication system

1. A method for determining signal and interference energy, the method comprising:

setting a threshold value;

determining an interference estimate (I est ) by comparing a channel estimate to the threshold value;

averaging the interference estimate (I est ) to determine average channel interference (I c ); and

determining, using a receiving device, interference energy (I) based on the interference estimate (I est ) and the average channel interference (I c ).

2. The method of claim 1 , further comprising:

comparing the channel estimate to the threshold value to determine a signal estimate (C est ); and

determining signal energy (C) based on the signal estimate (C est ) and the average channel interference (I c ).

3. The method of claim 2 , further comprising adjusting the threshold value based on the signal estimate (C est ).

4. The method of claim 2 , further comprising subtracting the average channel interference I c from the signal estimate C est to determine the signal energy C.

5. The method of claim 1 , wherein said determining comprises adding the I c to the I est to determine the interference energy I.

6. The method of claim 1 , wherein said averaging comprises:

dividing the interference estimate I est by a first count (N i ) that indicates how many samples of the channel estimate are below the threshold value to determine an interference average (I avg ); and

multiplying the I avg by a second count (N c ) that indicates how many samples of the channel estimate are above the threshold value to determine the average channel interference I c .

7. The method of claim 1 , wherein said setting comprises setting the threshold value based on a reference indicator.

8. The method of claim 1 , further comprising generating a truncation window that identifies a portion of the channel estimate as an interference portion, and wherein the interference portion is used to determine the interference estimate (I est ).

9. The method of claim 1 , further comprising obtaining the channel estimate by time filtering one or more symbols.

10. The method of claim 1 , further comprising subtracting the interference estimate I est from a received signal strength indicator to determine signal energy C.

11. An apparatus for determining signal and interference energy, the apparatus comprising:

one or more processors having:

threshold logic configured to set a threshold value and compare a channel estimate to the threshold value to determine an interference estimate (I est );

averaging logic configured to average the interference estimate (I est ) to determine average channel interference (I c ); and

summing logic configured to determine interference energy (I) based on the interference estimate (I est ) and the average channel interference (I c ).

12. The apparatus of claim 11 , wherein said threshold logic is further configured to compare the channel estimate to the threshold value to determine a signal estimate (C est ); and further comprising logic configured to determine signal energy (C) based on the signal estimate (C est ) and the average channel interference (I c ).

13. The apparatus of claim 12 , further comprising subtraction logic configured to determine the signal energy (C) based on subtraction of the average channel interference (I c ) from the signal estimate (C est ).

14. The apparatus of claim 12 , wherein said threshold logic is further configured to adjust the threshold value based on the signal estimate (C est ).

15. The apparatus of claim 11 , wherein said averaging logic comprises:

dividing logic configured to divide the interference estimate I est by a first count (N i ) that indicates how many samples of the filtered channel estimate are below the threshold value to determine an interference average (I avg ); and

multiplying logic configured to multiply the I avg by a second count (N c ) that indicates how many samples of the filtered channel estimate are above the threshold value to determine the average channel interference I c .

16. The apparatus of claim 11 , wherein said threshold logic is further configured to set the threshold value based on a reference indicator.

17. The apparatus of claim 11 , further comprising truncation logic configured to generate a truncation window that identifies a portion of the channel estimate as an interference portion and to use the interference portion to determine the interference estimate (I est ).

18. The apparatus of claim 11 , further comprising logic configured to obtain the channel estimate by time filtering one or more symbols.

19. The apparatus of claim 11 , further comprising logic configured to subtract the interference estimate IeS 1 from a received signal strength indicator (R) to determine signal energy C.

20. The apparatus of claim 11 , wherein said summing logic determines the interference energy (I) based on addition of the average channel interference (I c ) to the interference estimate (I est ).

21. An apparatus for determining signal and interference energy, the apparatus comprising:

means for setting a threshold value;

means for determining an interference estimate (I est ) by comparing a channel estimate to the threshold value;

means for averaging the interference estimate (I est ) to determine average channel interference (I c ); and

means for determining interference energy (I) based on the interference estimate (I est ) and the average channel interference (I c ).

22. The apparatus of claim 21 , further comprising:

means for comparing the channel estimate to the threshold value to determine a signal estimate (C est ); and

means for determining signal energy (C) based on the signal estimate (C est ) and the average channel interference (I c ).

23. The apparatus of claim 22 , further comprising means for adjusting the threshold value based on the signal estimate (C est ).

24. The apparatus of claim 22 , further comprising means for subtracting the average channel interference I c from the signal estimate C est to determine the signal energy C.

25. The apparatus of claim 21 , wherein said means for determining comprises means for adding the I c to the I est to determine the interference energy I.

26. The apparatus of claim 21 , wherein said means for averaging comprises:

means for dividing the interference estimate I est by a first count (N i ) that indicates how many samples of the filtered channel estimate are below the threshold value to determine an interference average (I avg ); and

means for multiplying the I avg by a second count (N c ) that indicates how many samples of the filtered channel estimate are above the threshold value to determine the average channel interference I c .

27. The apparatus of claim 21 , wherein said means for setting comprises means for setting the threshold value based on a reference indicator.

28. The apparatus of claim 21 , further comprising means for generating a truncation window that identifies a portion of the channel estimate as an interference portion and for using the interference portion to determine the interference estimate (I est ).

29. The apparatus of claim 21 , further comprising means for obtaining the channel estimate by time filtering one or more symbols.

30. The apparatus of claim 21 , further comprising means for subtracting the interference estimate I est from a received signal strength indicator to determine signal energy C.

31. A non-transitory computer-readable storage medium having stored thereon a computer program comprising instructions, which when executed by at least one processor, operate to determine signal and interference energy, the computer-readable storage medium comprising:

instructions for setting a threshold value;

instructions for determining an interference estimate (I est ) by comparing a channel estimate to the threshold value;

instructions for averaging the interference estimate (I est ) to determine average channel interference (I c ); and

instructions for determining interference energy (I) based on the interference estimate (I est ) and the average channel interference (I c ).

32. The non-transitory computer-readable storage medium of claim 31 , further comprising:

instructions for comparing the channel estimate to the threshold value to determine a signal estimate (C est ); and

instructions for determining signal energy (C) based on the signal estimate (C est ) and the average channel interference (I c ).

33. The non-transitory computer-readable storage medium of claim 32 , further comprising instructions for adjusting the threshold value based on the signal estimate (C est ).

34. The non-transitory computer-readable storage medium of claim 32 , further comprising instructions for subtracting the average channel interference I from the signal estimate C est to determine the signal energy C.

35. The non-transitory computer-readable storage medium of claim 31 , wherein said instructions for determining comprise instructions for adding the I c to the I est to determine the interference energy I.

36. The non-transitory computer-readable storage medium of claim 31 , wherein said instructions for averaging comprise:

instructions for dividing the interference estimate I est by a first count (N i ) that indicates how many samples of the filtered channel estimate are below the threshold value to determine an interference average (I avg ); and

instructions for multiplying the I avg by a second count (N c ) that indicates how many samples of the filtered channel estimate are above the threshold value to determine the average channel interference I c .

37. The non-transitory computer-readable storage medium of claim 31 , wherein said instructions for setting comprise instructions for setting the threshold value based on a reference indicator.

38. The non-transitory computer-readable storage medium of claim 31 , further comprising instructions for generating a truncation window that identifies a portion of the channel estimate as an interference portion and for using the interference portion to determine the interference estimate (I est ).

39. The non-transitory computer-readable storage medium of claim 31 , further comprising instructions for obtaining the channel estimate by time filtering one or more symbols.

40. The non-transitory computer-readable storage medium of claim 31 , further comprising instructions for subtracting the interference estimate I est from a received signal strength indicator to determine signal energy C.

41. A method for determining signal and interference energy, the method comprising:

setting a threshold value;

defining a truncation window;

determining an interference estimate (I est ) by comparing, a filtered channel estimate within the truncation window to the threshold value;

averaging the interference estimate (I est ) to determine average channel interference (I c ); and

determining, using a receiving device, interference energy (I) based on the interference estimate (I est ) and the average channel interference (I c ).

42. The method of claim 41 , further comprising:

comparing the filtered channel estimate outside the truncation window to the threshold value to determine a signal estimate (C est ); and

determining signal energy (C) based on the signal estimate (C est ) and the average channel interference (I c ).

43. The method of claim 42 , further comprising subtracting the average channel interference I from the signal estimate C est to determine the signal energy C.