MMSE Equalization Based Performance of Chaotic Interleaving Scheme for Iterative IDMA System

Abstract

Background: In this paper, a chaotic interleaving scheme is proposed for further performance improvement of Interleave Division Multiple Access (IDMA). Interleavers are used to generate permuted sequence of signals to be transmitted with optimum correlation. Methods: Random interleaving (RI) was the fundamental taxonomy and used to distinguish the different users in IDMA scheme. The logistic map based chaotic interleaving scheme is suggested for IDMA. The system is also combined with Minimum Mean Square Error (MMSE) equalizer to combat the effect of Inter Symbol Interference (ISI). Results: For the sake of simplicity, no pulse shaping is assumed at the transmitter and ISI channel is considered to be a fixed 3 tap channel. Simulations are performed in MATLAB. BPSK modulation is used. Furthermore, the results show that the IDMA with proposed logistic map based chaotic interleaver outperforms the traditional random interleaving scheme in terms of BER without the need of extra memory and computational complexity. Conclusion: The obtained results show the noticeable performance improvement of CI-IDMA with MMSE equalization in deep fading situations. Chaos based interleaver also offers other advantages such as less requirement of memory and small implementation complexity.