Multiband squelch method and apparatus

摘要: A squelch circuit for a radio receiver that detects the presence of speech by utilizing filter bank filtering an intermediate frequency or baseband signal from into band-pass signals, detecting magnitude and separating magnitudes noise detector. The detector determines if is present determining syllabic variations are in signals selects voice band average with maximum difference variations, generates decision when present. makes obtaining minimum comparing to threshold scaled associated variations. final made both indicate audio output enabled held on predetermined hold time.