Scalable spread-spectrum signal detection and acquisition processor

This invention relates to spread-spectrum communications systems, and more particularly to arrangements for determining the frequency or signal timing of such signals. A method allows determination of the presence of, the frequency of, and or the timing of a coded signal distributed in time, as for example a direct-sequence spread-spectrum signal or a signal having a coded header. According to the method, the received signal is correlated () with small sections of the spreading or header code, to produce partial correlations, as for example a 1024-chip spreading code is correlated in eight- or sixteen-chip portions. The result of each partial correlation is delayed () by an amount which results in temporal congruence or simultaneous occurrence of the partial correlations at a Doppler processor. The processor processes the simultaneous partial correlations, to produce signals which recur in the appropriate frequency bin at the recurrence rate of the spreading code. The frequency bin identifies the frequency of the received signals, and the time of the appearance of the signals at the bins is indicative of the time.