REDUCTION OF MULTIPATH EFFECTS AND CHANNEL DISTORTION IN BROADCAST TELEVISION

A new technique for the adaptive recursive removal of ghosts, using look-up and decision-based adaptive assignment of the parameters of the recursive algorithm, is described. A coarse channel estimation is used to select the initial parameter set. The algorithm requires a training signal in the vertical blanking interval. A master control algorithm keeps track of the echo-channel and system parameters and makes the necessary control decisions and echo assignments. Two-axis synchronous detection is used, and the echo-reduction operation is performed in the baseband. The system is targeted for digital NTSC and improved/extended/high-definition television (IDTV/EDTV/HDTV) receivers and is primarily intended for use in the reception of terrestrial VHF/UHF distribution.