LMMSE equalized DCSK communication system over a multipath fading channel with AWGN noise

Abstract

The advances in the development of chaos based communication system suggests that chaos shift keying (CSK) and its variant Differential CSK (DCSK) are one of the most promising candidates for practical implementation. In this paper a DCSK communication system incorporating a non coherent approach of demodulation based on a correlation detector is considered over a multipath fading channel. Specifically, it can be anticipated that the channel will introduce attenuation and cause distortion in the transmitted sequence due to fading and multipath. This distortion will cause Intersymbol interference (ISI) and will also add noise. Channel equalizers are capable of removing ISI from the transmitted sequence and also noise. In this paper the performance of a linear MMSE channel equalizer is analysed for a DCSK communication system over a multipath fading channel with additive white Gaussian noise.

BER Performance Improvement of Dual Chaotic Maps Based on STBC Communication System

“…In CSK, the chaotic signal will occur If a ′ + 1′ is transmitted and an inverted copy of the chaotic signal will appear If ′ − 1′ is transmitted. Therefore, the transmitted signal can be denoted as [18][19][20]24],…”

“…Then, the signal received at the receiver side is denoted as, r(t)=u(t) + n(t) … (18) where n(t) represents the AWGN with zero mean and variance 𝜎 𝑛 2 . At the receiver, the received signal is first despreaded by generating an exact replica of the chaotic signal that is generated at the transmitter, after that the symbols are integrated over symbol duration T s .…”

“…To compute the integral in equation ( 24), the distributed energy must be considered. Because of the PDF consider to be intractable, the method to compute the BER is evaluating the histogram of E b (l) followed by a numerical integration [18,19,18]. Applying numerical integration, the BER formula is expressed as,…”