A multicarrier DS/SSMA system with reduced multiple access interference and higher data rate in Rician fading channels

We propose to use multiple signature sequences (instead of one) per user in a multicarrier direct-sequence spread spectrum multiple access system in R ician fading channels. Every user has a distinct set of spreading sequences , with a different spreading sequence for each carrier in each user's set. By analysis and computer simulation, we show that when these sets of sequen ces are chosen to be mutually orthogonal complementary sets of sequences, m ultiple access interference (MAI) is reduced in Rician fading channels. We also show that we can pack symbols more closely together, resulting in a hi gher data rate. The proposed system with a distinct set of deterministic sp reading sequences per user has lower MAI and higher data rate than another system with one distinct random spreading sequences per user in Rician fadi ng channels. (C) 2001 Elsevier Science BN. All rights reserved.