Simulation Analysis of Time Variant Frequency Selective MIMO-OFDM Channel in Mobile Environment

Over the last few decades, there has been a tremendous growth in the wireless communication industry. In this new information age, high data rate and strong reliability features are becoming the dominant factor for a successful deployment of commercial networks. MIMOOFDM (Multiple Input Multiple Output – Orthogonal Frequency Division Multiplexing), a new wireless broadband technology has gained great popularity for its capability of high rate transmission and its robustness against multi-path fading and other channel impairments. The aim is to simulate a Time Variant Frequency Selective MIMO channel model for low velocities in the mobile environment. Space time modulation techniques have been employed in multiple receivers i.e. Single Input Multiple Outputs (SIMO), multiple transmitters i.e. Multiple Input Single Output (MISO) and then MIMO systems which provides transmit diversity. Multiple receiver antennas bring in the concept of antenna combining where the data can be combined at each antenna by various methods. In this paper, we are going to analyze two methods of receiver diversity namely, Selection combining and Maximal Ratio Combining (MRC). The simulation is carried on two channels namely, AWGN and Rayleigh fading channel. We have analyzed various cases for BER i.e. (Bit Error Rate) v/s SNR (Signal to Noise Ratio). The project simulates step by step various systems to ultimately arrive at a time variant frequency selective model and analyze its BER with different parameters. Extensive simulation results have been obtained for the same. Whole simulation process is done on MATLAB software. KeywordsSelection Combining, MRC, Alamouti STBC, OFDM, MIMO, Zero Forcing Equalizer, MATLAB