Patent ID: 6246885
Filing Date: 2001-06-12
Classification: H04B,H04W

Abstract:
A digital signal processor for use in a communication device which transmits and receives analog-modulated information signals when in an analog mode and which transmits and receives digitally-modulated information signals when in a digital mode, said digital signal processor comprising:a transmit audio processor for digitally processing an audio-band transmit signal when in said analog mode, wherein said transmit audio processor comprises:a compressor for digitally compressing said audio-band transmit signal, wherein said compressor comprises:an absolute value calculator for generating an absolute energy value signal in response to measuring an absolute energy value of said audio-band transmit signal;a digital filter, coupled to said absolute value calculator, for filtering said measured absolute energy value signal; anda divider, coupled to said absolute value calculator and said digital filter, for dividing said audio-band transmit signal by said digitally filtered, measured absolute energy value signal;a summer for digitally combining said compressed audio-band transmit signal with said regenerated supervisory audio tonea receive audio processor for digitally processing an audio-band receive signal when in said analog mode; anda supervisory audio tone processor, coupled to said receive audio processor and said transmit audio processor, for digitally detecting and transponding a supervisory audio tone.