Analysis of MIMO System over a Composite Fading Channel

Abstract

Multiple-input and multiple-output (MIMO) system has been recommended to enable future requirements of wireless communications. The efficient system designing demands an appropriate channel model, which should consider all the dominating effects of wireless scenario. Previously studied channel models like Multipath fading models only consider the small-scale fading effects, however, as it turns out that shadowing also degrades the system performance. Thus, some complex or less analytically submissive composite channel models have been proposed typically for single-input single-output (SISO) systems. These models are specifically used for mobile applications, however, a specific study of a model for MIMO system is required which can consider the radar clutters and different indoor/outdoor and mobile communication environments. Consequently, under such scenario, the performance improvement of MIMO system is also needed. The MIMO system performance improvement can be judgedin terms of low error rate and high capacity using spatial diversity and spatial multiplexing respectively. Spatial diversity is further categorized into transmit and receive diversity techniques. Maximal ratio combining (MRC) and orthogonal space time block codes (OSTBCs) have been recommended as receiver and transmitter diversity. newlineIn the beginning of this work, we have evaluated BER performance using OSTBC and MRC for distinct modulation techniques such as binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and 16-quadrature amplitude modulation (16-QAM) over different multipath fading channels viz. Rayleigh, Rician and Nakagami-m fading channels. Also, the same diversity techniques are used to evaluate error rate performance of MIMO system operating over single and double-Weibull fading channels, where, double scattering induces double fading in the wireless radio environment. For the first time, novel analytical expressions for cumulative distribution function.