Patent ID: 6498627
Filing Date: 2002-12-24
Classification: H04L,H04N

Abstract:
A brevity signaling module for a digital television (DTV) receiver which is equipped to receive and process a wideband overlay signal used for multipath processing, the brevity signaling module being adapted to enable reception of emergency broadcast messages and comprising:a receiver front end for receiving and detecting the wideband overlay signal; a squaring loop for squaring the detected wideband overlay signal detected by the receiver front end to generate a spectral line at 2&ohgr;, where &ohgr;=2&pgr;f and f is the overlay signal center frequency, said squaring loop including a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2&ohgr;, 2&ohgr;1, 2&ohgr;2, . . . , 2&ohgr;n, where 2&ohgr;1, 2&ohgr;2, . . . , 2&ohgr;n are different frequency tones assigned to different auxiliary functions; tone identification logic to detect, in the spectrum produced by said filter, a transmitted tone corresponding to one of the tones 2&ohgr;, 2&ohgr;1, 2&ohgr;2, . . . , 2&ohgr;n; and a control module responsive to the tone identification logic to determine whether normal multipath processing should be performed or whether multipath processing should be suppressed and auxiliary functions performed.