Performance Improvement Of MIMO System Using OSTBC Scheme and ML Detection Technique Under Rayleigh Channel

In this paper OSTBC coding technique and ML detection technique is used to improve the performance of 2×2 MIMO system. Without increasing the transmission power and bandwidth it has to be increase the data rate for user requirements. Due to impairments like inter symbol interference (ISI) and co-channel interference (CCI) it is very difficult to achieve the above requirement. This problem can be overcome by using the technology called Multiple input multiple output (MIMO). Diversity technique is used in the MIMO system achieves the desired reliability for available band limit of frequency spectrum with high data rate by mitigating the interference, multipath effects and signal scattering. Space-time block coding (STBC) technique including Alamouti and orthogonal STBC are implemented to mitigate the CCI and maximum likelihood (ML) equalizer to mitigate ISI. Finally, this is simulated in MATLAB and bit error rate (BER) is reduced and system performance is improved for BPSK under Rayleigh fading channel. The result shows that for OSTBC at BER 10^-4, the signal to noise ratio (SNR) is 9.8 dB.