In Wireless Communication, data transition is done through radio waves. Different standards had developed to improve the signal strength and BER of the signal. So, MIMO has the high demand after the 3G network and used by millions of people in the world for data sending and receiving purpose. Because of higher bandwidth the data transmission is in large amount. In this paper we had studied the MIMO system with different types of decoders. Through alamouti algorithm we had transmitted the signal through multiple antennas in different time instant and with the help of Rayleigh channel noise we had added noise in the signal and with the help of different types of decoders like ZF, MMSE, MRC, ML we had compared the BER of the signal and find out the decoder with better performance the others.