An Investigation into Time-Domain Approach for OFDM Channel Estimation

A time-domain based channel estimation for OFDM system with pilot-data multiplexed scheme is investigated. As an approximation to linear minimum mean square estimator (LMMSE), a time-domain based channel estimation is proposed where intra-symbol time-averaging and most significant channel taps selection are applied. The relation and differences of the proposed method to DFT-based LMMSE methods are discussed. The performances of the proposed method, DFT-based LMMSE method [15] and the methods of [16] and [17] are evaluated in multipath fading channels. The simulation results show that proposed method achieves almost the same performance as DFT-based LMMSE method and better BER performance than the other methods while keeping less complexity. Index Terms--Channel estimation, intra-symbol time-averaging, linear minimum mean square error estimator, most significant taps selection, orthogonal frequency division multiplexing (OFDM).