ECHO CANCELER COMPRESSION ENCODER/DECODER MULTIPLE UNIT AND ECHO ELIMINATING METHOD

摘要

PROBLEM TO BE SOLVED: To flexibly convert dissimilar companding rule telephone signals to be transmittable and to improve flexibility by individually controlling a companding rule of a channel of a programmable compression encoder/decoder. ;SOLUTION: Compression encoder/decoders (hereafter referred to as converters) 104, 108, 114 and 116 independently make a companding rule selectable by a register 130 including a pointer for a look-up table. A received signal from a near end is separated to a multiplexer 102 and inputted to the converter 104, and a companding rule to be used in each channel is selected according to a command from a controller and added to a converter 108 via an echo canceler 106. A program selecting an individual companding rule again is applied to each channel, and the each channel is multiplexed by a multiplexer 110 and transmitted to a target destination. Also, when a signal is received from a far end, it is similarly transmitted in a prescribed format to a near side subscriber by the converter 114, the canceler 106 and the converter 116.;COPYRIGHT: (C)2000,JPO