Blind Channel Estimation Based on Linear Precoding for OFDM Systems

Considering that channel estimation is crucial for coherent detection, a blind channel estimation method based on linear precoding for orthogonal frequency-division multiplexing (OFDM) systems is proposed in this paper. The proposed linear frequency-domain precoder is applied to each pair of blocks before they enter the OFDM system. Due to the introduced structure of precoder, the frequency-selective channel can be identified at the receiver based on cross-correlation operations, singular value decomposition (SVD) and resolving the scalar ambiguity. Because the linear frequency-domain precoder is creatively employed to channel estimation, the proposed blind method is computationally simple and requires no prior statistical information of channel or noise. And the proposed blind method has high spectral efficiency because it exploits no training sequence. Computer simulations have proved that this proposed blind method can identify the frequency-selective channels perfectly and have a good performance