DETECTION OF CO-CHANNEL INTERFERENCE IN DIGITAL TELEVISION SIGNALS

摘要

A receiver receives an ATV (e.g. HDTV) signal in an area that is subject to NTSC co-channel and other interferences. The received signal is precoded at the transmitter for enabling reduction of NTSC co-channel interference in the received signal. The received signal includes field sync signals that are successively field combed to produce a subtraction signal. The subtraction signal is comb filtered to reduce NTSC co-channel interference and applied to a comparator (36) along with the unfiltered subtraction signal. The comparator determines whether the level of NTSC co-channel interference is sufficiently great to subject the received ATV signal to comb filtering for reducing the NTSC co-channel interference.