High-data-rate transmission can be achieved by Spatially Multiplexed (SM) MIMO systems. Spatial demultiplexing at the receiver end is a difficult task. Thus, several research works has been developed for demultiplexing and decoding. In this paper three signal detection methods namely Zero-Forcing (ZF), Minimum Mean Squared Error (MMSE) and Maximum Likelihood (ML) are implemented. In Zero-Forcing method, noise enhancement is the problem. The complexity of implementing ZF and MMSE is much low but their performance is remarkably inferior to ML detection. Many active researchers are done to develop the signal detection methods based on the ML detection criterion while still aimed to achieve a near-optimal performance with low complexity. The comparative study of three methods is done in relevance to three digital modulation schemes namely Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK) and 16-Quadrature Amplitude Modulation (QAM). Simulation results also state that ML gives better performance as compared to ZF and MMSE detection methods. © 2014 IEEE.