In this paper, channel equalization techniques for full-digital HDTV systems are investigated Conventional equalization methods are surveyed and several channel are modeled for computer simulation. A VS-LMS (Variable Step size Least Mean Square) algorithm using the time constant concept is proposed and its performance is compared. Several equalization techniques for HDTV systems are simulated based on various channel models, and their characteristics are analyzed. Also the equalizer using fixed-point operations is simulated and its filter structure suitable for high bit rate transmission is also studied.