Semi-blind channel estimation for OFDM systems via an EM-Block algorithm

In this paper, we propose a semi-blind channel estimation method based on an Expectation-Maximization Block algorithm (EM-Block). In the OFDM communication context, such an algorithm still have a linear arithmetical complexity. However, it yields to an SNR improvement going up to 3 dB compared to classical training sequences based channel estimation method in the context of 5 GHz OFDM WLANs. The new algorithm performs better than already existing recursive algorithms and use much less prior information on the channel coefficients.