초록 ▼

A segmented, transversal correlator for use in a spread spectrum communications system accurately synchronizes to an incoming spread signal by passively searching for a particular section of a known reference PN code sequence. To achieve correlator lengths of greater than one data bit long, the corr

A segmented, transversal correlator for use in a spread spectrum communications system accurately synchronizes to an incoming spread signal by passively searching for a particular section of a known reference PN code sequence. To achieve correlator lengths of greater than one data bit long, the correlator may comprise a plurality of correlation subsections, each including a loading register for storing a different section of the overall reference PN code sequence. A section of the PN code sequence is transferred into a circulating register in each subsection through a parallel transfer. The dynamic, circulating PN code sequence is then correlated against statically stored analog samples of the incoming spread signal. When the dynamic PN reference code sequence is aligned with the corresponding PN sequence in the analog samples, a correlation signal is produced and magnitude detected to form a signal which is applied to a summation circuit. The summation circuit receives the outputs of each of the correlator subsections and produces a correlation output signal for the entire correlator.

대표청구항 ▼

Apparatus for correlating an input signal with a preselected bit sequence, comprising: a plurality of correlation subsections each comprising: means for sampling said input signal to produce a series of analog samples; means for storing a preset number of said analog samples, each new sample replaci

Apparatus for correlating an input signal with a preselected bit sequence, comprising: a plurality of correlation subsections each comprising: means for sampling said input signal to produce a series of analog samples; means for storing a preset number of said analog samples, each new sample replacing the oldest stored sample; buffer register means for storing a section of said preselected bit sequence; circulating register means parallel connected to said buffer register means for receiving said section of said bit sequence stored therein in response to a parallel load signal and sequentially circulating said bit sequence through the cells thereof; means for correlating said bit sequence in said circulating register with said analog samples to produce a correlation signal when said bit sequence in said circulating register is aligned with a corresponding sequence of said analog samples in said means for storing; delay means for serially transferring said input signal analog samples between each of said correlation subsections; and means for summing the correlation signals produced by each of said correlation subsections to generate a correlation output signal.