DIGITAL AUDIO SIGNAL RECEIVER

摘要

PROBLEM TO BE SOLVED: To simplify circuit constitution and to reduce the estimation errors of line quality by replacing transmitted digital audio signals with simulated sound generated in a background noise generation part based on the estimated result of a line quality estimation part. SOLUTION: An error detector 1 detects an error frame from demodulation signals 101 and a frame error rate(FER) measurement device 2 counts error detection signals 102 outputted by the error detector 1 for a fixed period and obtains an error frame rate FER. A control circuit 3 outputs a constant obtained beforehand corresponding to FER signals 103 outputted by the FER measurement device 2. A background noise generator 4 generates background noise and a multiplier 5 outputs the background noise whose level is adjusted corresponding to the FER by multiplying constant signals 104 outputted by the control circuit 3 and signals 105 outputted by the background noise generator 4. Then, an adder 6 adds the background noise to audio signals by adding the signals 106 outputted by the multiplier 5 and CODEC decoder output signals 107.