The Research Of Speech Coding Identification Technique In Communications System

There is no doubt that speech communication is an important intercourse tool for human. It is also the most common form in data communication systems. With the development of mobile communication and network, the speech communication technology has innovated and developed rapidly. With the increasing of network users, the integrating and diversifying of network service, the contradictions among bandwidth,system capacity and service quality are more and more obvious. Traditional 64kbps PCM speech coding can not satisfy the requirement of transmit bandwidth which is becoming more and more congested. So, hybrid coding who can reduce the bit-rate of speech without notably degrading its perceptual quality is used widely, and the speech coding represented by AMR are more mature in 3G standard.My thesis analyze the structure of speech coding, especially the parameter coding and hybrid coding. The first three chapters describe the basic principle and main technology of speech coding, and then introduce AMR which used in WCDMA.The fourth chapter proposed a method of speech coding identification based on the characteristics of coding. According to this method, if we do not know which speech coding is used at the transmitter, we can analyze the data stream received at the receiver and find out the exact coding style from the deal result, so that it is convenient to next step decoding. The whole course is simulated by computer test, and it shows a believed result.