Satellite speech quality measurement model based on a combination of auditory envelope feature and link loss

Abstract

This paper focuses on Speech Quality Measurement for a satellite mobile communication system. In contrast to ground mobile communication systems, satellite speech quality measurement suffers from obvious jitter of long delays and severe satellite link losses. Auditory feature sensation and link loss measurement are most popular speech quality measurement models. However, long delay would cause the auditory feature sensation model with spreading of power spectrum, which furtherly diffuses the auditory spectrums to prevent human from hear correct responses. Nevertheless, measured error of link loss measurement would be enlarged gradually during the process of voice services. Therefore, a new speech quality measurement model based on the combination of auditory feature extraction from voice signal envelope and link loss from channel distortion is proposed. We analyze signal temporal envelope features and make power spectrum into auditory feature spectrum. The jitter of long delay and link loss are modeled as parameters to modify and compensate for the auditory feature spectrum, which also reduce the measurement distortion from transmission Doppler frequency offset to voice tone in satellite channel. A more understandable sensation estimation scores is proposed to present speech quality scores. The experimental results reveal that the new model reduces evaluation RMSE by 9.8% and is suited to the satellite mobile communications environment.