摘要
本文介绍的全双工模数模语音置乱系统采用一种无需帧同步的置乱算法置乱语音信号,并以自适应回波抵消技术消除系统中的回波干扰。文中研究了语音置乱处理对自适应滤波算法性能的影响,导出了回波抵消的理论性能与自适应滤波器阶数的关系,对系统样机进行了实际性能测试。这种全双工模拟语音置乱系统可望用于移动通信网络和普通电话网络。
This paper presents an analog full-duplex speech scrambling system implemented with multiple DSP processors (TMS32010). The scrambling and deserambling algorithms are based on the asynchronous speech encryption technique proposed by Lee, et al. An adaptive echo canceller is employed to eliminate the echo interferences in the system. The influence of the scrambling process on adaptive filtering performance is studied by computer simulation. The relation between the echo cancellation level and the tap number of the adaptive filter is derived under the assumption of a practical echo channel model. The system has been implemented and tested, it is expected to be used to achieve full-duplex scrambled speech communication either in conventional telephone lines or in narrow-band radio channels.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
1989年第5期62-68,共7页
Journal of Southeast University：Natural Science Edition
关键词
保密电话
双工系统
语音置乱
消声
adaptive fillter, echo cancellation, duplex systoms/speech scrambling, secured telephone
