Study Of Speech Coding Applications In The Military Chain Of Command

In military communications systems, the technology of speech coding plays an important role in increasing the availability of the channel by compressing transmission bandwidth and reducing transmission bit-rate of the speech signal. In this paper, several low bit-rate speech coding algorithms are compared, then the reason for choosing Multi-band Excitation Vocoder as the research object is stated. The characteristics of the Multi-band Excitation Model are analyzed and the methods of picking up parameters of the speech model and synthesizing speech with these parameters are discussed in detail.The aims of a low bit rate speech coding algorithm is to attain high efficiency and concise algorithm on the basis of high quality of synthesize speech on the one hand, and on other hand is implemented in real time by DSP. In this paper, the AMBE2000 vocoder chip is used to build the hardware platform of the system and assembly language is used to compile the system's homologous software.This thesis is organized into six chapters as following :Chapter 1 "introduction" describes the history and the trend of the development of s-peech coding, packet switching and military communication network.Chapter 2 "MBE Speech model" introduces MBE speech-coding algorithm of the b-asic techniques to make further analysis.Chapter 3: Given out the viable architecture project about the military communication system;Chapter 4 "Hardware design", the AMBE2000 chip is used to design a set of telephony end of the military communication system in this chapter;Chapter 5 "software design". The chapter discussed the software design about the telephone system. Chapter 3 to Chapter 5 are the focuses of this paper.Chapter 6 "summary and prospect" makes a summary of this paper and inspects the unsolved problems in research and the field furthered probably in future.