Channel estimation for OFDM systems in non-sample-spaced multipath channels

A discrete fourier transform (DFT)-based channel estimator for orthogonal frequency division multiplexing (OFDM) systems is proposed. In multipath channels with non-sample-spaced time delays, the conventional DFT approach will cause power leakage and result in an error floor. Proposed is a novel symmetric extension DFT method to reduce the leakage power efficiently. Numerical results show that the proposed channel estimator can eliminate the error floor substantially.