移动调度终端语音前端处理系统的设计与实现

Design and Implementation of Mobile Dispatch Terminal Speech Front-end Processing System

移动调度系统广泛应用于诸多行业中,语音免提通信在移动调度系统中具有重要作用。但由于语音外放时移动终端易出现回声和噪声等问题,现有移动调度终端多数不支持语音免提通信,使得移动调度终端无法实现音视频同步通信。针对此类问题,基于归一化最小均方算法和最小均方误差-短时谱幅度估计谱减法,结合移动终端的数据处理能力,设计并实现集合回声消除和噪声抑制功能的语音通信前端处理模块,在编码之前对移动终端录制的语音信号进行回声消除和去噪处理。实验结果表明,该语音信号前端处理子系统可以在较低的计算复杂度下有效提升免提通信情况下移动终端的语音通信质量。

The mobile scheduling system is widely used in many industries and speech hands-free communication plays an important role in it. But as speech hands-free communication is most likely to be affected by echo and noise, many of existing mobile scheduling terminals do not support this function and it is impossible to realize audio and video communication simultaneously. Aiming at the above problem, a front-end processing sub-system, which consists of an echo-cancelling module and a noise-suppressing module,is proposed with the consideration of data processing ability of mobile terminal, which is based on Normalized Least Mean Square （NLMS） adaptive algorithm and Minimum Mean Square Error （MMSE）-Short Time Spectral Amplitude （STSA） spectral subtraction. Speech signals recorded on the mobile terminal are processed by the front-end processing modules before coding. Test results show that the front-end speech processing sub-system proposed notably improves the quality of voice communication in hands-free communication mode in the low computational compexity.