OFDM channel estimation with timing offset for satellite plus terrestrial multipath channels

In this paper, we propose a discrete Fourier transform (DFT)-based channel estimation and timing synchronization to cope with satellite plus intermediate module repeater (IMR) channels. Conventional DFT-based channel estimations suffer from the timing offset and incorrect channel impulse response, and this results in means square error (MSE) floor of channel estimations. Moreover, timing synchronization accuracy is also degraded on IMR channels. We, therefor, propose an improved DFT-based channel estimation by deciding significant channel taps based on a threshold and we derive this threshold with respect to MSE. Using results from proposed channel estimation, we compensate residual timing offset of conventional timing estimation.