FIR滤波器设计:基于遗传算法的频率采样技术

FIR Filter Design: Frequency Sampling Technique Based on Genetic Algorithm

遗传算法是一种模仿生物进化过程的随机搜索 ,这种生物模仿过程可以发现全局最优解。文中介绍了遗传算法在频率采样技术中的应用 ,结合 FIR数字低通、带通滤波器设计的两个例子 ,给出了算法实现的具体操作步骤和实验结果。文中还对标准遗传算法作了适当的改进。实验数据表明 ,采用遗传算法确定的频率过渡带样本值是最优的 ,设计的 FIR滤波器的频率特性优于查表法。

Frequency sampling technique is one of the usual methods in FIR digital filter design. When designing the digital filter by the technique, the value of transition bands sample obtained by searching for table must be confirmed in order to make the attenuation in the stopband maximal. However, the value obtained by searching for table cannot be ensured to be optimal. Genetic algorithm (GA) is a type of structured random search that mimics the process of biological evolution. The biological analogy suggests that such a procedure will lead to global optimal solutions for complex problems. A new application of GA for frequency sampling technique is presented. Two examples of lowpass and bandpass FIR filters are provided. The operation steps of GA realization and experimental results are given. Suitable improvements are also made for the standard GA. Experimental data show that the value of transition bands sample obtained by GA can be ensured to be optimal and the performance of the filter is improved.