Spatial multiplexing (SM), which employs multiple antennas at the transmitter and the receiver end, has recently been shown to be one of the most promising technologies in future wireless communication systems. In this paper analysis of high level modulations (i.e. M-PSK for different values of M) is done. Here AWGN and Rayleigh channels have been used for analysis purpose and their effect on BER for high data rates have been presented. The signal detection technique used at receiver end is Zero-Forcing Equalization (ZF) and Minimum Mean Square estimator (MMSE) (linear detection techniques).