摘要
为了满足短波窄带数字保密通信的需要,文中通过对LPC—10声码器进行深入研究,提出一种速率为1300b/s的极低速率语音编码算法。该算法在LPC—10声码器基础上,通过引入归一化互相关函数基音检测算法(NCCFPDA),提高了清浊音判决的准确率;通过引入线性谱(LSF),参数在同比特率量化的情况下提高的量化精度;通过引入联合帧和参数内插技术,降低了传输码率。经过以上改进,该算法在1300b/s的速率上获得了比较满意的合成语音,客观音质测试和非正式主观试听结果表明,其合成语音的可懂度和清晰度与传统的2400b/s线性预测LPC—10语音编码算法相当。
In order to meet the need of short-wave narrow-band digital 1 300 b/s speech algorithm is proposed. Based on Lpc-10 vocoder speech security communication, a new encoding techniques, the algorithm can improve the accuracy of the judgment of voiced and unvoiced speech by using a normalized cross-correlation function pitch detection algorithm（ NCCFPDA）, improve accuracy and efficiency of the quantification by using LSF parameters, and reduce the transmission rate by using super-frame and parameter interpolation techniques. The results of objective quality test and informal subjective listening test show that the intelligibility and articulation of the algorithm are comparative to that of the traditional 2 400 b/s LPC algorithm.
出处
《电子科技》
2009年第4期45-49,共5页
Electronic Science and Technology
