Fixed-point DSP Real-time Implementation of G.728 Speech Coding Algorithm

摘要

The G.728 standard is a 16kbit/s speech coding algorithm which one-way coding and decoding delay is not more than 2ms. It is of the public telephone network speech quality and is one of algorithms used in multimedia communication system. Because the algorithm is quite complex and needs much computation it is necessary to implement the algorithm on high speed DSP. This will promote it to become practical product. The paper selects TMS320C5402 DSP fixed-point chip to implement it, which has high function-price ratio. The paper presents the main software technologies of this project such as the control of synthesis filter stability and the transformation of data format in fixed-point algorithm and the improvement of logarithm gain prediction filter and so on.