A new finite alphabet based blind channel estimation for OFDM systems

A new blind channel estimation algorithm is proposed based on the finite alphabet property of the transmitted symbols and the correlation between the channel attenuations at the adjacent subcarriers. The new method preserves the classical OFDM transmitter structure with cyclic prefix (CP) used in all standardized multicarrier systems (such as DAB, IEEE802.11a, Hiperlan/2, etc.) as well as the newly proposed OFDM with zero padding (ZP). The new method proves to provide an unbiased channel estimates and its performance is independent of the channel zero locations. The new method also works using only short data records for channels with short delay spread (e.g., indoor channels).