Positive Effect of Severe Nakagami-mFading on the Performance of Multiuser TAS/MRC Systems with High Selection Gain

Chia-Chun Hung,Rong-Ching Wu,Ching-Tai Chiang,C Lee

doi:10.1155/2012/987631

Abstract

This paper investigates the positive effect of severe Nakagami-mfading on the performance of multiuser transmit antenna selection/maximal-ratio combining (TAS/MRC) systems with high selection gain. Both amount of fading (AF) and symbol error rate (SER) ofM-QAM are derived as closed-form expressions for integerm. For arbitrarym, the AF and the SER are expressible as a single infinite series of Gamma function and Gauss hypergeometric function, respectively. The analytical results lead to the following observations. First, the SER performance can demonstrate the positive effect of severe Nakagami-mfading on multiuser TAS/MRC systems with high selection gain. Second, the AF performance only exhibits the negative impact of severe fading regardless of high selection gain. Last, the benefit of severe fading to the system performance diminishes at high signal-to-noise ratio (SNR).

Highlights

Multiple-input multiple-output (MIMO) communications have been considered as suitable ways to improve the performance of wireless communications
MIMO maximum-ratio combining (MRC) systems under different conditions have been investigated in the last few years, no results seem to be available for the average symbol error rate (SER) of rectangular quadrature amplitude modulation (QAM) in noise-limited environments
This paper presents a positive impact of severe Nakagami-m fading on the performance of multiuser transmit antenna selection/maximal-ratio combining (TAS/MRC) systems with high selection gain

Summary

Introduction

Multiple-input multiple-output (MIMO) communications have been considered as suitable ways to improve the performance of wireless communications. In [14], tight closed-form expressions of outage performance were derived for the multiuser MIMO systems in Rayleigh fading channels. The closed-form expressions for the average symbol error rate of general rectangular QAM in MIMO MRC systems over Rayleigh fading channels are derived [16]. In [18], a closed-form expression for the AF was derived in a MIMO diversity system with space-time block coding (STBC) in Nakagami-m fading channels. We derive the AF of multiuser TAS/MRC systems as a closed-form expression in independent and identically distributed (i.i.d.) Nakagami-m channels with a positive integer m. Performance analyses, including outage probability, capacity, and symbol error rate (SER), were investigated for the TAS/MRC systems in Nakagami-m fading channels in [19,20,21]. All the derived expressions are verified by Monte Carlo simulations

Amount of Fading for Nakagami-m Models

Performance Analysis

Numerical and Simulation Results

Conclusions