(1) University of Bologna, ARCES, via Toffano, 2/2, 40125, Bologna, Italy;(2) University of Ferrara, ENDIF, via Saragat, 1, 44100, Ferrara, Italy;(3) University of Bologna, DEIS, viale Risorgimento, 2, 40100, Bologna, Italy
Abstract:
Multicode DS-CDMA systems assign more than one spreading sequence to each
of the users. In these systems multiple access interference (MAI) is made of a synchronous
and an asynchronous component. It is well known that asynchronous MAI alone can be
minimized by means of chaos-based spreading. Here we address the trade-off between
synchronous and asynchronous MAI by tuning the autocorrelation profile of the chaosbased
spreading codes. Improvements in the number of users allowed in the system is demonstrated in certain
load conditions with respect to the classical approach of providing each user with a set of
orthogonal sequences taken from an i.i.d. process.