Performance Analysis of MIMO OFDM System for Different Modulation Schemes under Various Fading Channels

Abstract: MIMO-OFDM (Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing) system has been recognized as one of the most popular and competitive technique in a wireless environment nowadays. The performance is calculated in terms of Bit Error Rate (BER) versus the Signal to Noise Ratio (SNR). In this paper we discuss the BER performance of the MIMO-OFDM system with two different equalizers (ZF and MMSE) for various modulation techniques i.e. BPSK, QPSK, 16-QAM and 64-QAM using multipath fading channels i.e. AWGN (Additive White Gaussian Noise), Rayleigh and Rician channel. The multicarrier modulation is employed, which gives advantages like inter symbol interference (ISI) reduction, high data rate, higher reliability, and better performance in multipath fading. The simulation results show that, with MMSE and ZF equalizers, the BER performances is better in MMSE equalizer. Further we analyzed in different fading channels for various modulation techniques in both the equalizers.

Keywords: OFDM, ZF and MMSE Equalizer, Multipath fading channels.