System for direct acquisition of received signals

Details System for direct acquisition of received signals System for direct acquisition of received signals

2007-04-24

2008-11-04

Wang, Ted (Department: 2611)

Pulse or digital communications

Spread spectrum

Direct sequence

C375S142000, C375S143000, C375S150000, C375S343000, C375S350000

Reexamination Certificate

active

07447259

ABSTRACT:
Signal processing architectures for direct acquisition of spread spectrum signals using long codes. Techniques are described for achieving a high of parallelism, employing code matched filter banks and other hardware sharing. In one embodiment, upper and lower sidebands are treated as two independent signals with identical spreading codes. Cross-correlators, in preferred embodiments, are comprised of a one or more banks of CMFs for computing parallel short-time correlations (STCs) of received signal samples and replica code sequence samples, and a means for calculating the cross-correlation values utilizing discrete-time Fourier analysis of the computed STCs. One or more intermediate quantizers may optionally be disposed between the bank of code matched filters and the cross-correlation calculation means for reducing word-sizes of the STCs prior to Fourier analysis. The techniques described may be used with BOC modulated signals or with any signal having at least two distinct sidebands.

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