GSM全速率语音编码算法分析及DSP实现  

ANALYSIS OF GSM FULL RATE SPEECH CODING ALGORITHM AND THE IMPLEMENTATION ON DSP

作　　者：何琴[1] 李小文[2] 

机构地区：[1]重庆邮电大学计算机科学与技术学院,重庆400065 [2]重庆邮电大学3G研究所,重庆400065

出　　处：《计算机应用与软件》2008年第11期123-124,175,共3页Computer Applications and Software

基　　金：科技型中小企业技术创新基金(04C26215111366)。

摘　　要：通过分析GSM全速率语音编码算法(RPE—LTP)的原理和特征,在实际应用中提出优化算法的两种方法。采用ADPCM改进算法的规则脉冲编码部分,使编码速率从13Kbit/s降为9Kbit/s;根据TMS320C55x DSP的特点,通过使用程序级别优化、去除不必要函数调用、优化判断语句等方法进行了代码优化。优化后算法的运算速度是19.63MCPS,需要11.9KW的程序空间和6.8KW的数据空间。从实验结果看,经优化后的程序在内存占用和运算复杂度方面都达到了预期目标,语音信号经编码器编码解码之后失真很小。This paper presents two methods to optimize GSM full rate speech coding algorithm （RPE--LTP） based on studying its principle and characteristics in application. It describes how to optimize Regular Pulse Excitation Coding of RPE--LTP algorithm by ADPCM which lead to reducing the coding rate from 13kbit/s to 9kbit/s. The source code is optimized based on the characteristics of digital signal processor TMS320C55x DSP, and through the methods such as performing program-level optimization, removing unnecessary function calls and generating efficient judge code. The speed of the optimized algorithm is 19.63MCPS, and it needs 11.9KW program memory and 6.8KW data memory. Experiments show that the optimized programs have met with the expectation in data storage and operational complexity. The distortion of the decoded speech is small.

关 键 词：RPE--LTP ADPCM DSP 优化 

分 类 号：TP276[自动化与计算机技术—检测技术与自动化装置] TN912.3[自动化与计算机技术—控制科学与工程]