Performances comparison of spreading sequences for very high efficiency DCSK system

Abstract

In this paper, we propose three different approaches in order to multiplex N bits of data using very high efficiency differential chaos shift keying (VHE-DCSK) system. This system allows higher spectral efficiency than differential chaos shift keying (DCSK) and high efficiency differential chaos shift keying (HE-DCSK) systems. Using Gaussian approximation method and under a white Gaussian noise channel (AWGN), theoretical bit error rate (BER) are calculated. Simulations in this environment show good agreement with analytical expressions and allow us to conclude that the first approach gives better BER performances when the number of transmitted bit (N) is large or if the spreading factor (M) is small.