RADIO CHANNEL SQUELCHING SYSTEMS

摘要

Detection of in-band noise in a radio communications voice channel is provided by mixing a signal having a known frequency into a radio signal containing a voice channel signal in an in-band range, thereby translating the voice channel signal out of the in-band range. The in-band range is thereafter examined for the presence of noise signal energy whose presence can be indicative of in-band noise. Squelching of the voice channel is provided in the event that in-band noise energy exceeds a predetermined threshold.