In the audio coded transmission system the background noise generation system

摘要

PROBLEM TO BE SOLVED: To reduce the change in a background noise(BGN) signal outputted from a receiving, side even when a BGN transmitted from a transmitting side in a silent section is sharply changed within a transmitting interval. ;SOLUTION: Background noise(BGN) signal code books 108, 210 for storing various BGN data and respective indexes corresponding to the BGN data are respectively arranged on the transmitting and receiving sides. On the transmitting side, respective indexes corresponding to BGN data similar to respective input signals to each frame are taken out from the code book 108 in a silent section and the obtained indexes are extracted at a fixed extraction interval and plural extracted indexes are collectively transmitted at a prescribed transmission interval. On the receiving side, plural indexes are received in each transmission interval and BGN data corresponding to the indexes are extracted from the code book 210 at the extraction interval and decoded as a BGN signal.;COPYRIGHT: (C)1997,JPO