Efficient use of pseudo-noise sequences in synchronous direct-sequence spread-spectrum multiple-access communication systems

In this paper, four different spreading schemes have been employed in a synchronous direct-sequence spread-spectrum multiple-access systems (S-DS/SSMA) over a Gaussian channel. These include different sets of pseudo-noise (PN) sequences, composite sequences, bit-scrambling on PN sequences and PN sequences as error-correction coding. The bit-error-rate (BER) performance of these schemes showed that the orthogonal sets of sequences is optimal for S-DS/SSMA system. Bit-scrambling on PN sequences cannot improve the BER performance. Error-correction coding is useful when the number of user is small