Method and System for a Sliding Window Phase Estimator for Wideband Code Division Multiple Access (WCDMA) Automatic Frequency Correction
Aspects of a method and system for a sliding window phase estimator for wideband code division multiple access (WCDMA) automatic frequency correction are presented. Aspects of the system may include one or more circuits that enable adjustment of a current demodulation frequency for receiving at least one subsequent symbol based on a computed weighted sum of a plurality of computed frequency error values. Each of the plurality of computed frequency error values may be derived from a current symbol, a corresponding previous symbol, and/or a previous frequency error value. The current symbol may include a current received symbol segment and one or more previously received symbol segments.
1 . A method, comprising:
determining, in a wireless device, a sum of a plurality of frequency error values associated with a current data symbol, wherein each of the plurality of frequency error values is based on a different segment of the current data symbol and on a corresponding segment of a previous data symbol; and
adjusting a value of a demodulation frequency for a subsequent data symbol based on the determined sum of the plurality of frequency error values associated with the current data symbol.
2 . The method of clam 1 , wherein each of the plurality of frequency error values is based on a different set of segments of the current data symbol and on a corresponding set of segments of the previous data symbol.
3 . The method of claim 1 , comprising generating a chip level signal based on a signal demodulated utilizing a current value of the demodulation frequency.
4 . The method of claim 3 , comprising despreading the chip level signal by a corresponding despreading code to generate each segment of the current data symbol.
5 . The method of claim 4 , comprising selecting, based on a previously determined sum, a number of chips in the chip level signal to be despread by the corresponding despreading code.
6 . The method of claim 1 , comprising determining the frequency error value associated with a segment of the current data symbol based on a phase value of the segment and a phase value of the corresponding segment of the previous data symbol.
7 . The method of claim 1 , comprising determining the frequency error value associated with a segment of the current data symbol based on a complex conjugate of the corresponding segment of the previous data symbol.
8 . The method of claim 1 , wherein the determined sum is a weighted sum based on a maximal ratio combining of the plurality of frequency error values.
9 . The method of claim 1 , wherein the determined sum is a weighted sum based on an equal gain combining of the plurality of frequency error values.
10 . The method of claim 1 , comprising adjusting the value of the demodulation frequency for the subsequent data symbol based on a plurality of determined sums associated with a plurality of diversity signals received by the wireless device.
11 . A system , comprising:
one or more processors and/or circuits operable to determine a sum of a plurality of frequency error values associated with a current data symbol, wherein each of the plurality of frequency error values is based on a different segment of the current data symbol and on a corresponding segment of a previous data symbol; and
the one or more processors and/or circuits operable to adjust value of a demodulation frequency for a subsequent data symbol based on the determined sum of the plurality of frequency error values associated with the current data symbol.
12 . The system of clam 11 , wherein each of the plurality of frequency error values is based on a different set of segments of the current data symbol and on a corresponding set of segments of the previous data symbol.
13 . The system of claim 11 , wherein the one or more processors and/or circuits operable to generate a chip level signal based on a signal demodulated utilizing a current value of the demodulation frequency.
14 . The system of claim 13 , wherein the one or more processors and/or circuits operable to despread the chip level signal by a corresponding despreading code to generate each segment of the current data symbol.
15 . The system of claim 14 , wherein the one or more processors and/or circuits operable to select, based on a previously determined sum, a number of chips in the chip level signal to be despread by the corresponding despreading code.
16 . The system of claim 11 , wherein the one or more processors and/or circuits operable to determine the frequency error value associated with a segment of the current data symbol based on a phase value of the segment and a phase value of the corresponding segment of the previous data symbol.
17 . The system of claim 11 , wherein the one or more processors and/or circuits operable to determine the frequency error value associated with a segment of the current data symbol based on a complex conjugate of the corresponding segment of the previous data symbol.
18 . The system of claim 11 , wherein the determined sum is a weighted sum based on a maximal ratio combining of the plurality of frequency error values.
19 . The system of claim 11 , wherein the determined sum is a weighted sum based on an equal gain combining of the plurality of frequency error values.
20 . The system of claim 11 , wherein the one or more processors and/or circuits operable to adjust the value of the demodulation frequency for the subsequent data symbol based on a plurality of determined sums associated with a plurality of diversity signals received by the wireless device.