Patent ID: 6141372
Filing Date: 2000-10-31
Classification: H04B

Abstract:
An apparatus for digitally downconverting and despreading a multi-channel analog direct sequence spread spectrum signal, comprising:a free-running, non-steered, clock generator which outputs an A/D sample clock;the A/D sample clock having a rate which is an integral multiple of a chip rate of said spread spectrum signal;an A/D converter which receives the spread spectrum signal and the A/D sample clock and outputs a digitized multi-channel signal from said spread spectrum signal;a local pseudo-noise sequence signal source which generates M local pseudo-noise sequences, wherein M is an integer greater than 1; anda multi-channel complex downconverter/polyphase filter which receives the digitized multi-channel signal and the A/D sample clock and sample timing phase control signals, simultaneously filters and downconverts the digitized multi-channel signal to baseband, corrects timing phase misalignment between the digitized multi-channel signal and the locally generated pseudo-noise sequences, and outputs a multi-channel complex corrected baseband signal.