Earticle

MIMO-OFDM technology is a combination of multiple-input multiple-output (MIMO) wireless technology with orthogonal frequency division multiplexing (OFDM) that has been recognized as one of the most promising techniques to support high data rate and high performance in different channel conditions. Again, Alamouti’s space time block coding scheme for MIMO system has drawn much attention in 4G wireless technologies just because of its decoding simplicity. This paper presents the performance evaluation of Alamouti’s space-time block coded (ASTBC) MIMO-OFDM systems covering channel model, channel capacity, coding scheme and diversity gain. The mathematical model of capacity is derived for deterministic, random and correlated Rayleigh fading channels. The channel capacity per unit bandwidth is evaluated as a function of SNR. It is observed that the channel capacity increases with the number of antenna added to the system due to the more diversity gain of Alamouti’s code. Finally we investigate the correlated MIMO fading channel with different correlation matrix. At the higher SNR value, independent and identically distributed (i.i.d) channel capacity outperforms the correlated channel capacity. But At very low SNR value correlated channel capacity outperforms the i.i.d channel capacity.