Performance of multi-subchannel direct-sequence spread-spectrum multiple-access communications over multipath fading channels

The performance of multisubchannel direct-sequence spread-spectrum multiple-access systems in multipath fading channels is investigated. A wideband channel is divided into several subchannels and each subchannel carries the same messages but is modulated by different pseudo-random sequences. Independent fading in different subchannels is assumed. The upper and lower bounds of the system error probability are derived. Numerical computation shows that, over multipath fading channels, for a given system processing gain, the multisubchannel direct-sequence spread-spectrum multiple-access system has a performance advantage over the single-channel system. The results obtained also hold for conventional direct-sequence spread-spectrum multiple-access systems with diversity technique