A Low-Complexity Channel Estimator for MIMO-OFDM Systems

In this paper, a low complexity channel estimator for MIMO OFDM systems is proposed. A frequency domain filtering scheme based on the concept of temporal windowing for noise power reduction outside the window is developed to enhance the performance of the simple least square estimator. This approach can eliminate the extra FFT/IFFT operations required in the conventional time domain scheme. A temporal Hamming window is adopted to further reduce the computing complexity of the frequency domain filtering. Simulation results indicate the proposed scheme can significantly improve both the NMSE and BER performance of the LS channel estimator. Compared with the time domain most significant tap (MST) scheme, the proposed scheme has comparable performance but requires much less computing complexity. The proposed scheme also has the advantage in hardware implementation over the MST scheme