DELAY DISTORTION COMPENSATING METHOD IN PRIVACY COMMUNICATION

摘要

PURPOSE: To reduce quality deterioration caused by a delay distortion of a signal of a voice by detecting a transmission delay time measuring signal, comparing a mark frequency component and a space frequency component and compensating a delay of a privacy sound signal subjected to FFT processing, based on a detected delay time. ;CONSTITUTION: A delay time measuring signal in which frequency modulation is applied to the center part and both end parts of a transmission band in a privacy sound signal subjected to high speed Fourier-transformation scramble processing, which is transmitted through a wire transmission line and passes through an A/D converter 71 is extracted and detected by a measuring signal detector 76. This detected output is supplied through an FFT processor 77, a delay time detector 78 compares a mark frequency component and a space frequency component of the delay time measuring signal and detects a delay time of a transmission line, and a delay of a receiving privacy sound signal is compensated by a delay compensation processing part 74. Accordingly, quality deterioration based on a delay distortion corresponding to a delay caused by a transmission line of the privacy sound signal is reduced.;COPYRIGHT: (C)1993,JPO&Japio