Added pilot semi-blind channel estimation scheme for OFDM in fading channels

Abstract

An added pilot semi-blind (APSB) scheme used for channel identification of OFDM systems is proposed. This scheme uses pilot symbols that are added directly to the data symbols and hence does not require any additional bandwidth for its implementation. To remove the pilots, a two dimensional Wiener filter is used for the purpose of channel Interpolation by using successive iterations. Although its complexity increases with additional iterations, the APSB scheme is found to compare favorably to existing blind schemes proposed for the OFDM system in terms of bit error rate and convergence.