Spread spectrum correlator for recovering CCSK data from a PN spread MSK waveform

A spread spectrum demodulation apparatus for recovering information signals that have been combined with a prescribed encoding sequence and spread-modulated onto a carrier for transmission comprising:

• first means for providing a replica of said prescribed encoding sequence;
• second means for providing a replica of the spreading sequence through which the combined information signals have been spread spectrum-modulated onto said carrier;
• third means, coupled to said first and second means, for combining respective portions of said encoding sequence with said replica of said spreading sequence and producing therefrom a plurality of first output signals;
• fourth means, coupled to said third means, for combining each of said plurality of first output signals with received unknown information signals and producing therefrom a plurality of second output signals;
• and
• fifth means, coupled to said fourth means, for successively summing said second output signals to derive an output representative of the original information signals.

A spread spectrum signal demodulation apparatus for a recovering information signals that have been combined with a prescribed encoding sequence and spread spectrum-modulated onto a carrier for transmission comprising:

• first means for storing a replica of said prescribed encoding sequence;
• second means for combining said replica of said prescribed encoding sequence with signals corresponding to the spreading sequence through which the combined information signals have been modulated onto said carrier;
• and
• third means for correlating the output of said second means with received unknown information signals to obtain an output representative of the original information signals, said third means comprising a plurality of respective correlator stages, each stage correlating a first input with a second input and generating a respective output representative of the correlation between said first and second inputs, said first input corresponding to a respective portion of the output of said second means and said second input. corresponding to said received unknown information signals, and including an output link from which said output representative of the original information signals is derived, and including means for selectively coupling the outputs of said respective correlator stages to said output link.