Chaotic spreading sequences with multiple access performance better than random sequences

The authors present a theoretical analysis on a performance index W for chaotic spreading sequences, which characterizes the multiple access interference introduced by crosscorrelation of a sequence set in asynchronous DS/CDMA systems. Using the ergodic theory, W is expressed in terms of ensemble-averaged autocorrelation functions and simple explicit formulae for W are obtained, under the assumption of independent seeds. Based on this analysis one can design chaotic spreading sequences performing better than ideal random sequences with respect to multiple access interference.