Research And Realization Of Speech Coding Algorithm

Because the communication channel and computer networks limit the bit rate of the transmission code flow, speech coding technique has been developed and there come many fine speech coding algorithms and standards, which are applying in all kinds of fields. ITU G.729 in this paper is a 8kbit/s speech coding algorithm based on a Conjugate-Structure Algebraic Code Excited Linear Prediction (CS-ACELP) coding technique, which has such fine composed speech quality, moderate complexity and lower delay that has been the main coding algorithm in the speech communication. In the research, the purpose is mastering the principle of the standard coding algorithm and optimizing it. Speech compression coding is the emphase in the dissertation, and the writer describes the algorithm about CS-ACELP. To achieve high-quality speech and real-time implementation, CS-ACELP has been revised by novel schemes. In this paper, at first some key techniques of the coding algorithm and G.729 are introduced. And then it is introduced that how to apply DSP language realizing the algorithm and optimize the code. Finnally, the hardware design of the speech transmission scheme and the testing result are developed. The outcome of the research: 1, Making full use of the characters of the TMS320C54xx series'DSP and the software tool supported by TI the writer develops the optimizing method and introduces its steps and the key techniques. 2, The research develops the real-time project of realizing the G.729 and the schemes of choosing the devices. The final conclusion: the optimized code can achieve high-quality speech and real-time implementation.