Performance analysis of MIMO-OFDM channel re-estimation methods

Multiple-input multiple-output orthogonal frequency division multiplex (MIMO-OFDM) is a wireless transmission system that is currently being deployed to the latest fourth generation wireless communication system (4G). Channel state information (CSI) is required at the receiver in order to calculate the optimum decoding matrix. Using training sequence, channel property can be calculated using channel estimation technique such as least square (LS) or minimum mean square error (MMSE). The accuracy of those techniques is limited by the number of training sequence that is used for channel estimation. In this paper, we suggest that instead of just using the training sequence only, the entire transmitted symbols can be used for channel estimation. In order to do that the channel property will be estimated twice before the desired data is decoded. The proposed method has higher accuracy of estimation compared to conventional method.