Quasi Orthogonal Space Time Block Code (QO-STBC) can provide full-rate transmission and low decoding complexity. This paper deals with channel estimation for Quasi Orthogonal Space Time Block Code (QO-STBC) encoded Orthogonal Frequency Division Multiplexing (OFDM) based Multiple Input multiple Output (MIMO) Code Division Multiple Access (CDMA) system. Using the QO-STBC coding property, we analysis the weight performance that reduce the computational complexity of system. The design of channel estimation method is proposed by considering Minimum Mean Square Error (MMSE), Zero Forcing (ZF), and Singular Value Decomposition (SVD) that involves four transmit antennas and four receive antennas. Such filter facilitates the use of standard equalizer or decoder that has been designed to mitigate the Inter Symbol Interference (ISI) effect. In this paper analytical results show that the BER analysis of Minimum Mean Square Error (MMSE) algorithm using various modulation techniques outperforms as compared to other channel equalization techniques.