Patent ID: 6233554
Filing Date: 2001-05-15
Classification: H03M

Abstract:
A circuit for controlling the gain of an audio band processor, the circuit comprising:a first variable gain amplifier in said audio band processor for receiving an analog audio signal;an analog to digital converter in said audio band processor for converting said analog audio signal to a digital audio signal;an interface circuit for encoding said digital audio signal and for arranging said digital audio signal into a sequence of encoded transmit frames; anda vocoder for measuring an energy level of said sequence of encoded transmit frames, and for generating digital gain control bits in response to said measured energy level, and for generating a sequence of encoded receive frames, each receive frame comprising a predetermined number of encoded digital audio signal data bits and a predetermined number of padding bits, and for replacing said padding bits with said digital gain control bits;wherein said interface circuit adjusts a gain level of said first variable gain amplifier in response to said digital gain control bits.