Method for testing voice quality in a mobile communication system using perceptual linear predictive-cepstrum mean substraction

摘要

PURPOSE: A method for evaluating a speech quality in a mobile communication system using a PLP-CMS(Perceptual Linear Predictive-Cepstral Mean Subtraction) method is provided to define a PLP-CMS speech quality evaluating method with reference to a human acoustic characteristic and perform an objective speech quality evaluation using the PLD-CMS speech quality evaluating method. CONSTITUTION: A delay time is measured using a cross correlation of an inputted original voice and a voice signal distorted through a CDMA and PSTN channel. The inputted original voice and the distorted voice signal are synchronized using the measured delay time. A human acoustic characteristic is reflected to a spectrum of the inputted original voice and a spectrum of the synchronized and distorted voice for analyzing a perceptual linear prediction. An influence by a channel which has an influence through an entire interval of the original voice and the distorted voice signal is removed using a cepstral mean subtraction. A PLP cepstral distance of the original voice and the distorted voice is calculated for measuring distortion information of the inputted voice.