Channel Estimation and Interference Cancellation of Feedback Interference for DOCR in DVB-T System

This paper considers a problem of unwanted feedback interferences caused by coupling from the transmit antenna to the receive antenna in the digital video broadcasting-terrestrial (DVB-T) digital on-channel repeater (DOCR) system. We model the DVB-T DOCR system and propose a feedback interference cancellation method based on the linear minimum mean square error (LMMSE) estimation of the feedback interference channel. Since the accurate estimation of the feedback interference channel is an important factor that determines the performances of the feedback interference cancellation, the channel estimation by averaging the estimated channel and iterative decision feedback cancellation method are proposed. Simulation results of signal-to-noise ratio (SNR) relation between the reference SNR and the processed SNR are presented and the theoretical analysis is performed to verify the simulation results. The proposed methods are compared to the conventional method on the typical urban 6 channels with maximum Doppler frequencies of 0 Hz and 3 Hz in terms of SNR, bit error rate and various transmission modes in the DVB-T system. Simulation results and the theoretical results show that the proposed method outperforms the conventional method.