Redundant Precoding Assisted Blind Channel Estimation for OFDM Systems

Because channel estimation can play a crucial role on coherent detection of the information symbols in each data block, this paper proposes a redundant precoding assisted blind channel estimation approach for orthogonal frequency-division multiplexing (OFDM) systems. A redundant linear frequency-domain precoder is applied on each pair of blocks before they enter the OFDM system. Due to the introduced structure, the frequency-selective channel can be identified at the receiver based on auto-correlation operations, singular value decomposition (SVD) and resolving the scalar ambiguity. The proposed channel estimation method has low computational complexity and requires no prior statistical information of channel or noise. And the proposed blind method has high spectral efficiency owing to exploiting no training sequence. Computer simulations confirm that this proposed blind channel estimation method can identify the frequency-selective channels perfectly and have a good performance