プレフィルタとポストフィルタを含むAD/DA変換系の設計と音声信号圧縮系への適用

抄録

AD/DA conversion has become a core technology in digital signal processing. Traditionally, AD/DA systems are composed of the post-filter and the quantizer, and it is required to satisfy the low quantization noise and the low distortion characteristics. However, it is well known that there exists trade-off between these two characteristics. In previous studies, we proposed a new design method of AD/DA system that includes pre-filter, in addition to the traditional AD/DA systems. Post and pre-filters are designed towards the original signal, so as to minimize the effect of noise and distortion due to quantization. In this paper, we verify the AD/DA systems with post and pre-filters by using the voice signal compression system. We evaluate the effectiveness using DMOS (Degradation Mean Opinion Score) method.