| 摘要 |
<p>CODE DIVISION MULTIPLEXER USING DIRECT SEQUENCE SPREAD SPECTRUM SIGNAL PROCESSING A plurality of transmitters synchronized to a common clock each transmit a data signal spread by a common bipolar pseudo-random code having a different predetermined assigned code sequence clock. A receiver, synchronized to the clock, discriminates the signal transmitted by a predetermined transmitter from signals transmitted by the others by generating a first bipolar pseudo-random code that is a replica of the common bipolar pseudo-random code and has a code sequence shift corresponding to that of the predetermined transmitter, and a second bipolar pseudo-random code and has an unassigned code sequence shift. The difference between the first and second bipolar pseudo-random code sequences, which is a trinary code code sequence, is cross-correlated with the incoming signals. The cross-correlated despreads only the signal applied by the sequence having the predetermined code sequence shift. Each receiver includes a number of correlation detectors offset from each other by a fraction of a code chip together with decision circuitry to identify cross-correlated peaks for optimum synchronization.</p> |
