The Research And Optimization Of Low-bitrate Speech Coding Based On Satellite Mobile Communication

In recent years,China is making efforts in our own mobile satellite telecommunication system.This will change the present situation that our country is relying on the Global Star and Maritime satellite system imported from other countries.At the same time,this will improve service abilities in the comprehensive information transition,resources security,especially in disaster prevention,disaster relief,counter-terrorism,maritime and some other applications.Therefore,the formation of satellite mobile communication network in China is imminent,but in our country,the satellite mobile communication network at present will have great development space,it is made up of Satellite Station,gateway station,service simulation platform and interfaces between them.Our country is in very urgent need for the development of satellite mobile communication business simulation and test platform.Voice service is the most basic and important service of the communication system,this paper will research and realize the voice business in satellite mobile communication test platform.Firstly,to build a set of platform software based on the service logic.Secondly,the paper researches on a new MELP with new framing and quantization method based on United States Federal MELP speech coder.Finally,it is evaluated according to speech encoding and decoding complexity,MOS speech quality score performance evaluation.Speech coder is the basic of voice services,so the paper not only researches on building the platform,but also improves the MELP algorithm in theory,and the new method reduces framing time,framing bits,complexity,but the quality of speech doesn't decline.