高效短时DFT压扩器的实现  

Implementation of the High-speed Short Time DFT Compander

作　　者：袁晓辉[1] 夏良正[1] 

机构地区：[1]东南大学自动控制系

出　　处：《信号处理》1995年第3期187-192,共6页Journal of Signal Processing

基　　金：国家教委留学回国人员基金

摘　　要：压扩技术作为提高伟输信号信噪比的有效手段，在通信系统中得到了广泛应用。短时DFT压扩器根据瞬时谱直接在频域对信号压扩而无需峰值检测，对降低衰落噪声、提高信号传输质量比传统压扩器更为有效，但短时DFT压扩器运算量大，计算效率低。本文通过对传输信号的序号模运算和引人循环相关，构筑了高速化短时DFT压扩器，在保证提高信噪比的前提下，有效减少了运算量和提高了计算效率，具有较大的理论意义和实用价值。Companding is a useful technique for improving the signal to noise ratio (SNR) over poor radio channels . The short time DFT compander is realized with companding the instantaneous spectrum components on the frequency domain rather than estimating the signal envelope . Comparing with conventional companders, it is able to reduce fading noise to improve speech quality without any distortions . However , it is suffered from the great deal of computation . In this paper , the high-speed short time DFT compander is realized by deducing the modulc calculation of time variable and employing the circular correlation . It not only improves the SNR but also greatly reduces the amount of computation .

关 键 词：压扩器 语音信号处理 短时分析 离散傅里叶变换 

分 类 号：TN912.3[电子电信—通信与信息系统]