Speech Coding for Narrowband Channels

该项目开发和评估新的语音编码算法，用于以每秒2.4和8.0千比特之间的速率进行语音通信。特别强调的是对由噪声信道（例如移动的无线电通信系统）引起的传输比特差错具有鲁棒性的算法。所研究的算法使用基本的语音压缩技术，如矢量量化，分析。合成，感知加权，短。以及长期线性预测和矢量激励编码以及几种更新的技术。这项工作对于通信技术是重要的，特别是在移动的无线电系统中，其中带宽是宝贵的资源，并且由于有限的射频功率约束而必须容忍相对高的错误率。

This project develops and evaluates new speech coding algorithms for voice communication at rates between 2.4 and 8.0 kilobits per second. Particular emphasis is given to algorithms that are robust to transmission bit errors caused by noisy channels such as, for example, mobile radio communication systems. The algorithms under study use basic speech compression techniques such as vector quantization, analysis.by.synthesis, perceptual weighting, short. and long.term linear prediction, and vector excitation coding as well as several newer techniques. This work is important to communication technology particularly in mobile radio systems where bandwidth is a precious resource and relatively high error rates must be tolerated due to limited radio frequency power constraints.