MBE声码器的基音估计研究

主要对NBE声码器了研究，简单介绍了MCIBE编解码算法的基本原理。NBE编码基于3个参数(基音周期、谱包络参数、以及每个频带的U／V判决信息)的提取，其中基音周期的估计准确性将直接影响到语音的合成质量；文中重点分析了基音估计部分；考虑到在实际应用中可能会出现的基音错锁问题，提出了一种改进的基音估计算法。改进算法不但可以省略基音平滑这一过程，简化了整个算法过程；而且改善了基音周期的帧间连续性，并提高了语音合成的自然度。

Research on Estimation of Pitch Period OF MBE Vocoder

This paper researches mainly on Multiband Excitation,puts a brief introduction on the theory of MBE coding and decoding.MBE Vocoder bases on calculating 3 parameters(pitch period,Spectral Envelope,U/V Information),thereinto,the quality of synthetical speech lies most on estimating Pitch Period.This paper puts emphasis on analyzing estimation of pitch period.In view of the mistakes about estimation of pitch period that may be found in practice,an improved algorithm of estimation of pitch period is proposed.This improved algorithm can not only omit smoothness of pitch period and simplify the whole algorithm;but also increase the continuous of pitch period between frames and improve the quality of synthesis speech.