Equalizer in high definition television(HDTV) transmission system

Proposes a new type equalizer for HDTV transmission system based on VSB technology to cope with severely distorted channel situation. The ordinary equalizer often use, decision feedback (DFE) structure and recursive equalizing algorithm. Because of the mulitipath spreading in FIR, the ordinary DFE has slow convergence of the weight coefficient in the former condition, and the recursive algorithm cannot work with the signal submerged in interference. The new equalizer adopts indirect equalizing style, and new algorithm is used for fast estimation of the channel impulse responses used as initial weight coefficients of the adaptive equalizer. A modified DFE structure of decision feedback equalizer is proposed to get faster convergence of weight coefficients. The simulation results show that the new style equalizer can while the ordinary equalizer cannot work well in severely distorted propagation channel, and was tested in Brazil.