This paper presents a Multiple-Input Multiple-Output (MIMO) transmission scheme that combines the spatial modulation (SM) with MIMO spatial multiplexing technique. The SM uses NA number of active antennas to transmit the same symbol, the proposed MIMO model uses the NA number of active antennas to transmit different symbols at the same time to increases the spectral efficiency of the system. A Zero-Forcing based equalizer is used at the receiver to jointly estimate the transmitted symbols as well as the index of active antennas combination. The zero-forcing based detection scheme suffers from a higher complexity and Inter channel Interference (ICI) with less probability of error (BER). For solving the problem in this paper a MMSE based detection scheme is used which improve the BER (bit error probability). The performance of MMSE based detection scheme is evaluated in an uncorrelated flat Rayleigh fading channel and compared with the Zero-forcing based spatial modulation and MMSE Detector. Keywords-,AWGN(Additive white Gaussian noise) ,Rayleigh fading channel, Antenna Combination Binary phase shift keying (BPSK), Bit error rate (BER), Inter-symbol interference (ISI), Minimum mean square error (MMSE), MIMO System, Spatial Modulation, Spatial Multiplexing, Zero Forcing (ZF).