Applying high-speed adaptive equalization to HDTV broadcast receivers

As a part of the current energetic development of high-definition television (HDTV) technology, interest has grown in potential methods for direct broadcast of HDTV signals. To meet the simultaneous constraints of technical feasibility and government regulation, such a broadcast signal must carry at least 20 Mb/s and must be spectrally limited to less than 6 MHz (in the US). These constraints have led to the consideration of using multilevel QAM signals. Owing to the terrestrial line-of-site nature of the transmitter-to-user propagation path, considerable multipath distortion is expected. This paper demonstrates how recent advances in adaptive algorithms and semiconductor technology can be combined to develop a cost-effective solution to the removal of this distortion.