Turbo Coded OFDM Combined with MIMO Antennas Based on Matched Interleaver for Coded-Cooperative Wireless Communication

Rahim Umar,Fengfan Yang,Shoaib Mughal

doi:10.3390/info8020063

Abstract

A turbo coded cooperative orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO) antennas scheme is considered, and its performance over a fast Rayleigh fading channel is evaluated. The turbo coded OFDM incorporates MIMO (2 × 2) Alamouti space-time block code. The interleaver design, and its placement always plays a vital role in the performance of a turbo coded cooperation scheme. Therefore, a code-matched interleaver (CMI) is selected as an optimum choice of interleaver and is placed at the relay node. The performance of the CMI is evaluated in a turbo coded OFDM system over an additive white Gaussian noise (AWGN) channel. Moreover, the performance of the CMI is also evaluated in the turbo coded OFDM system with MIMO antennas over a fast Rayleigh fading channel. The modulation schemes chosen are Binary Phase shift keying (BPSK), Quadrature phase shift keying (QPSK) and 16-Quadrature amplitude modulation (16QAM). Soft-demodulators are employed along with joint iterative soft-input soft-output (SISO) turbo decoder at the destination node. Monte Carlo simulated results reveal that the turbo coded cooperative OFDM system with MIMO antennas scheme incorporates coding gain, diversity gain and cooperation gain successfully over the direct transmission scheme under identical conditions.

Highlights

As there is an explosive increase in the utilization of wireless mobile communication, the demand for high-speed data rates among the users of 3G and 4G wireless mobile communications has increased considerably
The performance of the code-matched interleaver (CMI) is evaluated in the turbo coded orthogonal frequency division multiplexing (OFDM) system with multiple-input multiple-output (MIMO) antennas over a fast Rayleigh fading channel
Monte Carlo simulated results reveal that the turbo coded cooperative OFDM system with MIMO antennas scheme incorporates coding gain, diversity gain and cooperation gain successfully over the direct transmission scheme under identical conditions

Summary

Introduction

As there is an explosive increase in the utilization of wireless mobile communication, the demand for high-speed data rates among the users of 3G and 4G wireless mobile communications has increased considerably. The authors in [1,2] proved, by performing rigorous information theoretic analysis, that the cooperation technique leads to higher data rate as compared to a non-cooperative counterpart. In this context, in order to exploit spatial diversity, some repetitive algorithms such as Information 2017, 8, 63; doi:10.3390/info8020063 www.mdpi.com/journal/information “decoded and forward (DF)” and “amplify and forward (AF)” were developed for improving the bit error rate (BER) but at the cost of reduced spectral efficiency [3]. A slightly different framework has emerged in the literature commonly known as coded cooperation [5] In this technique, instead of only repeating information bits, each user transmits an extra redundancy for its cooperating partner. The authors in [9] implemented the classical

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