Pulse or digital communications – Spread spectrum – Direct sequence
Reexamination Certificate
2007-10-03
2010-10-05
Ha, Dac V (Department: 2611)
Pulse or digital communications
Spread spectrum
Direct sequence
C375S149000, C375S150000, C375S362000, C370S510000
Reexamination Certificate
active
07809046
ABSTRACT:
In one embodiment, a timing-offset estimator calculates a correlation value for each sample of an OFDM signal having a cyclic prefix for each OFDM symbol. The correlation value is provided to a tapped delay line that applies a separate weight to each of 2V correlation values, where V is the length of the cyclic prefix and the weights are based on a triangular weighting scheme that increases linearly from the first value, peaks at the Vthvalue, and decreases linearly to the 2Vthvalue. A stream of combined, squared correlation values is generated by combining and squaring the 2V weighted correlation values for each sample of the OFDM signal. For each cyclic prefix of the OFDM signal, a timing-offset estimate is determined based on a detected peak value in the stream of combined, squared correlation values. A timing-offset estimator with triangular weighting scheme may be implemented using recursive processing.
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Mujtaba Syed
Wang Xiaowen
Agere Systems Inc.
Brown Craig M.
Ha Dac V
Mendelsohn Steve
Mendelsohn, Drucker & Associates P.C.
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