Return link time adjustments in FDD OFDMA or SC-FDM systems
A method for adjusting timing in a Frequency Division Multiplexing (FDM) system, including receiving a request to perform a timing correction, generating a time domain FDM symbol, and controlling the timing correction in the time domain FDM symbol by at least one of adjusting a length of a cyclic prefix, overlapping a portion of adjacent FDM symbols, adjusting a symbol windowing length, or utilizing a return link (RL) silence interval.
1. A method for adjusting timing in a Frequency Division Multiplexing (FDM) system, comprising:
receiving a request to perform a timing correction;
generating a time domain FDM symbol; and
controlling the timing correction in the time domain FDM symbol by at least one of adjusting a length of a cyclic prefix, overlapping a portion of adjacent FDM symbols, adjusting a symbol windowing length, or utilizing a return link (RL) silence interval.
2. The method according to claim 1 , wherein the RL silence interval is used to advance or backoff the RL transmission.
3. The method according to claim 1 , wherein the cyclic prefix is adjusted for a single FDM symbol.
4. The method according to claim 1 , wherein a plurality of cyclic prefixes are adjusted for a single timing correction.
5. The method according to claim 4 , wherein the plurality of cyclic prefixes is adjusted, if the timing correction request exceeds a threshold.
6. The method according to claim 5 , wherein the threshold is based on a fraction of a cyclic prefix length.
7. The method according to claim 5 , wherein the threshold is about twenty-five percent of a cyclic prefix length.
8. The method according to claim 1 , wherein the cyclic prefix is adjusted for a first FDM symbol in a frame having a plurality of FDM symbols.
9. The method according to claim 1 , wherein the timing correction adjusts a guard interval duration in the overlapped portion of the adjacent FDM symbols.
10. The method according to claim 1 , wherein the FDM system is at least one of an Orthogonal Frequency Division Multiplexing (OFDM) System or a Single Carrier-Frequency Division Multiplexing (SC-FDM) System.
11. An apparatus for synchronizing a Frequency Division Multiplexing (FDM) access terminal, comprising:
means for receiving a request to perform a timing correction;
means for generating a time domain FDM symbol; and
means for controlling the timing correction in the time domain FDM symbol by at least one of adjusting a length of a cyclic prefix, overlapping a portion of adjacent FDM symbols, adjusting a symbol windowing length, or utilizing a return link (RL) silence interval.
12. The apparatus according to claim 11 , wherein the RL silence interval is used to advance or backoff the RL transmission.
13. The apparatus according to claim 11 , wherein the cyclic prefix is adjusted for a single FDM symbol.
14. The apparatus according to claim 11 , wherein a plurality of cyclic prefixes are adjusted for a single timing correction.
15. The apparatus according to claim 14 , wherein the plurality of cyclic prefixes is adjusted, if the timing correction request exceeds a threshold.
16. The apparatus according to claim 15 , wherein the threshold is based on a fraction of a cyclic prefix length.
17. The apparatus according to claim 15 , wherein the threshold is about twenty-five percent of a cyclic prefix length.
18. The apparatus according to claim 11 , wherein the cyclic prefix is adjusted for a first FDM symbol in a frame having a plurality of FDM symbols.
19. The apparatus according to claim 11 , wherein the timing correction adjusts a guard interval duration in the overlapped portion of the adjacent FDM symbols.
20. The apparatus according to claim 11 , wherein the FDM system is at least one of an Orthogonal Frequency Division Multiplexing (OFDM) System or a Single Carrier-Frequency Division Multiplexing (SC-FDM) System.
21. An apparatus operable in a wireless communication system, the apparatus comprising hardware logic configured to:
receive a request to perform a timing correction;
generate a time domain FDM symbol; and
control the timing correction in the time domain FDM symbol by at least one of adjusting a length of a cyclic prefix, overlapping a portion of adjacent FDM symbols, adjusting a symbol windowing length, or utilizing a return link (RL) silence interval.
22. The apparatus according to claim 21 , wherein the logic configured to receive is a processor block, the logic configured to generate the time domain FDM symbol is an IFFT block, and the logic configured to control the timing correction is a baseband processing block.
23. The apparatus according to claim 21 , wherein the cyclic prefix is adjusted for a single FDM symbol.
24. The apparatus according to claim 21 , wherein a plurality of cyclic prefixes are adjusted for a single timing correction.
25. The apparatus according to claim 24 , wherein the plurality of cyclic prefixes is adjusted, if the timing correction request exceeds a threshold.
26. The apparatus according to claim 25 , wherein the threshold is based on a fraction of a cyclic prefix length.
27. The apparatus according to claim 21 , wherein the RL silence interval is used to advance or backoff the RL transmission.
28. The apparatus according to claim 21 , wherein the cyclic prefix is adjusted for a first FDM symbol in a frame having a plurality of FDM symbols.
29. The apparatus according to claim 21 , wherein the timing correction adjusts a guard interval duration in the overlapped portion of the adjacent FDM symbols.
30. The apparatus according to claim 21 , wherein the FDM system is at least one of an Orthogonal Frequency Division Multiplexing (OFDM) System or a Single Carrier-Frequency Division Multiplexing (SC-FDM) System.
31. A computer program product, comprising:
a non-transitory computer readable medium, comprising
code for causing a computer to provide processing of communications signals, said code comprising:
instructions to receive a request to perform a timing correction;
instructions to generate a time domain FDM symbol; and
instructions to control the timing correction in the time domain FDM symbol by at least one of adjusting a length of a cyclic prefix, overlapping a portion of adjacent FDM symbols, adjusting a symbol windowing length, or utilizing a return link (RL) silence interval.
32. The computer-readable medium according to claim 31 , wherein the RL silence interval is used to advance or backoff the RL transmission.
33. The computer-readable medium according to claim 31 , wherein the cyclic prefix is adjusted for a single FDM symbol.
34. The computer-readable medium according to claim 31 , wherein a plurality of cyclic prefixes are adjusted for a single timing correction.
35. The computer-readable medium according to claim 34 , wherein the plurality of cyclic prefixes is adjusted, if the timing correction request exceeds a threshold.
36. The computer-readable medium according to claim 35 , wherein the threshold is based on a fraction of a cyclic prefix length.
37. The computer-readable medium according to claim 35 , wherein the threshold is about twenty-five percent of a cyclic prefix length.
38. The computer-readable medium according to claim 31 , wherein the cyclic prefix is adjusted for a first FDM symbol in a frame having a plurality of FDM symbols.
39. The computer-readable medium according to claim 31 , wherein the timing correction adjusts a guard interval duration in the overlapped portion of the adjacent FDM symbols.
40. The computer-readable medium according to claim 31 , wherein the FDM system is at least one of an Orthogonal Frequency Division Multiplexing (OFDM) System or a Single Carrier-Frequency Division Multiplexing (SC-FDM) System.
41. A method for determining a timing correction in a Frequency Division Multiplexing (FDM) system, comprising:
receiving a transmission from an access terminal;
determining a timing correction based on the received transmission; and
transmitting the timing correction to the access terminal,
wherein if the determined timing correction exceeds a threshold, the method further comprises determining a plurality of timing corrections.
42. The method according to claim 41 , wherein the plurality of timing corrections are determined for a single received transmission.
43. The method according to claim 41 , wherein the threshold is based on a fraction of a cyclic prefix length.
44. The method according to claim 41 , wherein the threshold is about twenty-five percent of a cyclic prefix length.
45. An apparatus for determining a timing correction in a Frequency Division Multiplexing (FDM) system, comprising hardware logic configured to:
receive a transmission from an access terminal;
determine a timing correction based on the received transmission; and
transmit the timing correction to the access terminal,
wherein if the determined timing correction exceeds a threshold, the hardware logic is further configured to determine a plurality of timing corrections.
46. The apparatus according to claim 45 , wherein the plurality of timing corrections are determined for a single received transmission.
47. The apparatus according to claim 45 , wherein the threshold is based on a fraction of a cyclic prefix length.
48. The apparatus according to claim 45 , wherein the threshold is about twenty-five percent of a cyclic prefix length.
49. An apparatus for determining a timing correction in a Frequency Division Multiplexing (FDM) system, comprising:
means for receiving a transmission from an access terminal;
means for determining a timing correction based on the received transmission;
means for determining whether the determined timing correction exceeds a threshold;
means for partitioning the determined timing correction into a plurality of timing corrections when the determined timing correction exceeds the threshold; and
means for requesting the access terminal to implement the plurality of timing corrections.
50. A computer program product, comprising: a non-transitory computer-readable medium comprising code for: receiving a transmission from an access terminal; determining a timing correction based on the received transmission; determining whether the determined timing correction exceeds a threshold; partitioning the determined timing correction into a plurality of timing corrections when the determined timing correction exceeds the threshold; and requesting the access terminal to implement the plurality of timing corrections.