线性滤波器输出信噪比的最小上界和降噪性能

The Minimum Up Bound of Linear Filters'Output Signal to Noise Ratio and Their Noise Reduction Characteristics

为了分析和评价各种线性滤波器的降噪性能，本文提出一种新的计算线性滤波器输出信噪比公式，并用统一的方法推导出线性滤波器输出信噪比的最小上界。它既适用于功率有限的信号，也适用于能量有限的信号，即适用于已知波形，也适用于随机信号，本文还证明了被广泛应用的，根据不同准则推导出的维纳滤波器和匹配滤波器均能改善输出信噪比．

In order to evaluate the noise reduction performance of various linear filters,we propose a new formula to calculate their output signal to noise(ANR)and use a unified approach to derive the minimum up bound of linear filters'output SNR.It is applicable to any kinds of input signals:the power limited signals, the energy limited signals,the known signals, and the random signals.We also demonstrate that the often used Wiener Filter and Match Filter, although derived from different criteria,can improve their output signal to noise ratios.