New sets of binary functions for generating orthogonal codes with negative auto-correlation based on bernoulli chaotic map

摘要

Generation of orthogonal spreading codes is utmost importance in synchronous CDMA systems in order to realize zero MAI (multiple access interference). Walsh codes and OVSF (orthogonal variable spreading factor) codes are well known as conventional orthogonal spreading codes. On the other hand, spreading codes with appropriate negative auto-correlation are useful for asynchronous CDMA systems in the sense that they can reduce bit error rate compared to uncorrelated spreading codes. In this paper, we give new sets of binary functions for generating orthogonal codes with negative auto-correlation using Bernoulli chaotic map.