VOICE AUTOMATIC GAIN CONTROL APPARATUS AND VOICE AUTOMATIC GAIN CONTROL METHOD, AND EFFECTIVE VALUE CALCULATION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a technology of simplifying function blocks configuring AGC, relieving a load of arithmetic processing using a polynomial and capable of using a DSP so as to process a plurality of channels at the same time. SOLUTION: An arithmetic section 4 is characterized in to include: a voice delay section 7 for storing past voice signals x(n-1) to x(n-(N+1)); a subtraction section 9 for subtracting the oldest voice signal x(n-(N+1)) stored in the voice delay section 7 from a one-preceding total sum S(n-1); an adder section 10 for summating an output from the subtraction section 9 and a square of the newest voice signal to provide an output of a total sum S(n); an average value calculation section 11 for calculating an average value of the total sum values outputted from the adder section 10; and a delay section 8 for storing the total sum S(n-1) being a one preceding value of the total sum S(n) so as to control a plurality of channels at the same time. COPYRIGHT: (C)2006,JPO&NCIPI