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 and the methods of Chini, Wu, El-Tanany and Mahmoud (see IEEE Trans. on Broadcasting, vol.44, no.1, p.2-11, 1998) and of Yeh and Lin (see IEEE Trans. on Broadcasting, vol.45, no.4, p.400-409, 1999) 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