TDS-OFDM Based HDTV Transmission over Fast Fading Channels

Consumer electronics are expecting high-definition television (HDTV) services not only at home, but also in high-speed vehicles like cars, train, subways, etc. However, time domain synchronous OFDM (TDS-OFDM) could only provide HDTV services in static or low-speed channels, but not in fast fading channels due to the severe mutual interferences between the time-domain training sequence (TS) and the OFDM data block. Without changing the original TDS-OFDM signal structure, this paper firstly proposes the idea of regarding transmission parameter signaling (TPS) symbols embedded in the OFDM data block as frequency-domain pilots. This new perspective breaks the conventional concept that the training information of TDS-OFDM exists only in the time domain. Then, the two-dimensional channel estimation method jointly exploiting the time-domain TS as well as the frequency-domain pilots is proposed to improve the system reliability over fast fading channels. Simulation results demonstrate that reliable HDTV transmission could be achieved when the moving speed of consumer electronics is up to 120 km/h(1).