一种估计模拟分解滤波器组系数偏差的算法

模拟器件工艺偏差是制约混合滤波器组模拟数字转换器系统信号重构精度的主要原因,准确地得到模拟分解滤波器组传递函数是完成信号重构的首要条件.为解决上述问题,本文提出一种估计传递函数系数偏差的算法.该算法根据输入信号的信息以及信号通过模拟滤波器组后的采样数据,便可以准确地估计出偏差范围在±20%的模拟滤波器传递函数系数的偏差值.实验中分别采用2阶和3阶模拟滤波器传递函数模型,其谐振频率的估计值与理想偏差值的标准偏差分别为1.10%和0.56%.将估计值应用于单通路滤波混合滤波器组系统进行仿真,输出信号可以达到14位精度,完成了系统重构功能,仿真验证了该算法的可行性.

New Algorithm for Estimating Coefficient Deviations of Analog Analysis Filter Banks

The resolution of hybrid filter bank(HFB) based analog/digital converter(ADC) is found to be very sensitive to analog process imperfections, thus, obtaining the accurate analog filter transfer function is important. This paper presents a new algorithm for estimating the analog imperfections. The algorithm can estimate the accurate values as long as the analog deviations are within ±20%, assuming that the available information is only the input signal and the sampled output one. The standard deviations from typical values of the resonance frequency are 1.10% for the second-order analog filter and 0.56% for the third-order one. The input signal is perfect when the estimated values are applied to a single-channel filtering HFB ADC system. Simulation results prove the feasibility of the proposed algorithm.