Generalised Barker-like PN sequences for quasisynchronous spread-spectrum multiple-access communication systems

Abstract

The generalised Barker (1953)-like pseudonoise (PN) sequence is introduced. Three theorems are established for such a set of sequences. A computer search algorithm is derived based on these theorems to search for the generalised Barker-like PN sequences employing two design parameters m and l. The multiple-access-interference (MAI) performance of a quasisynchronous direct-sequence spread-spectrum multiple-access communication system (QS-DS/SSMA) employing the generalised Barker-like PN sequence is examined and compared with an asynchronous DS/SSMA communication system employing random binary sequence and Gold sequence. It was found that the MAI performance of the QS-DS/SSMA system is superior when both m and l are small satisfying the inequality 2N≥l2+3m (m-1)+1, where N is the period of sequences. It was also shown that the bit-error-rate performance of a synchronous DS/SSMA system employing the generalised Barker-like PN sequence is 13.65 dB superior to that of the Gold sequence.