A Low Complexity Optimal LMMSE Channel Estimator for OFDM System

Linear minimum mean square error (LMMSE) is the optimal channel estimator in (MSE) perspective, however, it requires matrix inversion with cubic complexity. In this paper, by exploiting circulant property of frequency autocorrelation RHH, an efficient LMMSE estimation method has been proposed for orthogonal division multiplexing (OFDM) based on fast Fourier transformation (FFT) and circular convolution theorem. Finally, computer simulation carried out to compare classical LS methods terms performance measure computational The results show that achieves exactly same as conventional much lower