Pulse or digital communications – Spread spectrum – Direct sequence
Reexamination Certificate
2006-09-05
2006-09-05
Tran, Khanh (Department: 2611)
Pulse or digital communications
Spread spectrum
Direct sequence
C375S262000, C375S341000
Reexamination Certificate
active
07103090
ABSTRACT:
Based on the MAP criterion, a category of optimal timing estimators is disclosed. These estimators work with known or unknown channel information, and with received information bits over frequency-selective, slowly fading channels. A sub-optimal timing estimator with a k-taps, multiplication-free, finite impulse response (FIR) filter is also disclosed, where k equals 22 when the Barker sequence of length11is employed. The sub-optimal estimator is robust with respect to frequency offset impairment. Using simulations, the disclosed timing estimators are demonstrated to be effective. However, in the special case of timing estimation without channel information, in a multi-path channel with a long delay spread, it is disclosed that it is more effective to estimate the received carrier phases and amplitudes of multi-paths before timing estimation.
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Chang Chao-Ming
Lo Chen-Yu
Mediatek Inc.
Thomas Kayden Horstemeyer & Risley
Tran Khanh
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