Beamforming Based Receiver Scheme for DVB-T2 System in High Speed Train Environment

In this paper, the received signal from the different base stations (BSs) of the second generation of Terrestrial Digital Video Broadcasting (DVB-T2) in the high-speed-train (HST) scenario is modeled as a fast time-varying signal with the multiple Doppler frequency offsets. The interference caused by the multiple Doppler frequency offsets and the channel variations, and the signal to interference plus noise ratio of the received signal, are derived for the DVB-T2 receiver. The results of the theoretical analysis show that the interference greatly degraded the performance of the DVB-T2 system. To suppress the interference, we proposed a beamforming based receiver scheme for DVB-T2 system. By using the new signal processing scheme for the received signal vector from the antenna array, one can separate the received signal with the multiple Doppler frequency offsets into the multiple signals, each of which is with a single Doppler frequency offset. The separated signals are compensated by the corresponding Doppler frequency offsets and equalized by the estimated channel responses respectively, then combined into a signal to be demodulated. The results of the simulation show that the proposed scheme can effectively suppress the interference and greatly improve the performance of the DVB-T2 system in the HST environment.