Performance Evaluation of Comparison of Sphere Decoder with Other Equalization Techniques on 2x2 MIMO Systems Using Rayleigh and Rician Flat Fading Channels

MIMO systems has been proved to be one of the most promising and emerging wireless technologies that can efficiently increase the data transmission rate, improves system coverage, and enhances the link reliability. By employing multiple antennas both at transmitter and receiver side, MIMO techniques enables a new dimension-the spatial dimension-that can be utilized in different ways to combat the impairments of wireless channels. In MIMO system technology, there is intersymbol interference present between the symbols. This paper is focussed on Equalization techniques for Rayleigh Flat fading and Rician Flat fading. It is a well known technique for combating intersymbolinterference. Furthermore, in this paper, we have discussed sphere decoder for MIMO wireless communication system. We analyze the performance of Sphere Decoder with other equalization techniques like Zero forcing(ZF), minimum mean squared error equalizer(MMSE) and maximum likelihood decoder by comparing the Bit error rate(BER). Simulation has been done on MATLAB and result shows that SD provides us the better result in comparison to other techniques for a 2 × 2 MIMO using BPSK in Rayleigh flat fading channel as well as in Rician flat fading.