Robust DFT-based channel estimation for burst OFDM systems

A robust discrete Fourier transform (DFT)-based channel estimation for burst orthogonal frequency division multiplexing (OFDM) systems is proposed in this paper. The conventional DFT-based channel estimation methods improve the performance by neglecting nonsignificant channel taps. However, the error floor occurs at high signal-to-noise when useful channel information is discarded, especially in non-sample-spaced channel. To solve this problem, we propose a modified DFT-based channel estimation method. Based on the noise power estimated in the frequency domain, which does not suffer from the energy leakage of channel path, we design the threshold for detecting the significant channel taps. Moreover, a wider region with fixed width is designed to decrease the energy loss of channel. Simulation results show that the proposed method is robust to the distribution of channel paths, and the error floor is eliminated.