Voice Compression Codec Algorithm. The Tetra Protocol And Its Dsp Implementation,

In 1998, ETSI publicized TETRA protocal, which is a standard of digital trunked radio communication system. Combined with the practical item of train attemper command system based on the TETRA protocol, this article researched the algorithm of TETRA speech compression coding and its DSP implementation.Short-time calm characteristics of audio signal is educed from the produce-mechanism of audio signal, Based on which the Linear Prediction Coding, the Analythsis-By-Synthesis technology, and Code-Excited Linear-Prediction coding are discussed. After researching the algorithm of TETRA 4.567kbit/s ACELP, its implementation scheme of software and hardware based on ADSP 21535 chips is designed, and the detail implementation procedure is presented in this article, the result is content. Furthermore, the algorithm is optimized based on the practical application and document.