A Study On The Error Performance Of Rectangular And Cross MQAM In MIMO Fading Channels

Joint transmit antenna selection(TAS)and receive maximum-ratio combining(MRC)antenna diversity with ideal Channel State information(CSI)is antenna diversity scheme of implementing low complexity in multiple input multiple output wireless communication system.Differentially Encoded Quadri-Phase Shift Keying(DE-QPSK)and Rectangular/Cross Quadrature Amplitude Modulation(R/XQAM)have characteristics of high spectral efficiency and simple implementation.This thesis intends to investigate the bit error rate(BER)performance of DE-QPSK,RQAM and Cross-32 QAM using joint TAS/MRC antenna diversity over flat Nakagami fading channels with arbitrary fading parameters.In practice,perfect channel state information(CSI)is difficult to obtain due to the impact of feedback delay.In this paper,the pilot assisted modulation and channel prediction are applied to the TAS/MRC antenna diversity system using DE-QPSK and R/XQAM modulation and analytical expressions of the BER performance are derived.Space time block code(STBC)and Two-dimensional RAKE receivers(2D-RAKE)can improve the BER performance of Direct Sequence-Code Division Multiple Access(DS-CDMA)system of using the above techniques.This thesis intends to investigate the BER performance of DS-CDMA system over correlated Nakagami fading channels using STBC coding DE-QPSK,R/XQAM modulation and MRC 2D-RAKE receiver respectively.Chapter 1 presents a brief review of DE-QPSK and R/XQAM over fading channel,the TAS/MRC of channel prediction and joint application of STBC and 2D-RAKE receiver.Chapter 2 derives the exact analytical expressions for average symbol error rate(ASER)of DE-QPSK,RQAM and Cross-32 QAM using joint TAS/MRC antenna diversity over Nakagami fading channels of arbitrary parameters under perfect CSI,theoretical calculation and simulation results are also given.Chapter 3 use moment generating function method and approximate expression of Gaussian Q-function to derive the exact and approximate analytical expressions for the ASER of DE-QPSK and R/XQAM over time-selective Rayleigh block fading channel with minimum mean square error Wiener predictor and TAS/MRC antenna diversity respectively.Finally,theoretical calculation and simulation results are given.Chapter 4 derives exact analytical expressions for the ASER of STBC DE-QPSK,R/XQAM and MRC 2D-RAKE receiver over frequency selective correlated Nakagami fading channel and is vertified by computer simulation,at the same time chapter 4 also clarifies the number of transmit and receive antenna,the fading coefficient,the angular spread,the average path loss factor rate and the transmit antenna correlation coefficient on the impact of BER performance of DS-CDMA system of using STBC DE-QPSK and R/XQAM and 2D-RAKE receiver.Chapter 5 is conclusion of this paper.