Implementation of fractional fourier transform in digital filter design

Abstract

In literature, so many window functions are available to process the signals. The quality newlineof window based filtering is mainly based on different parameters like band width(B.W), side newlinelobe fall of ratio (or suppression of spectral leakage) and side lobe attenuation(SLA). No specific newlinewindow is suitable for all applications, every window has its own merits and demerits. Basically newlinethe selection window function is always be a trial and error method, compromising the trade-off newlinebetween main lobe width and spectral leakage. An attempt has been made to present spectral newlineanalysis of different window functions like Boxcar, Bartlett, Hanning and Hamming functions, newlinecombination of window functions consists of Boxcar and Blackmann-Harris, tunable newlinedifferentiator/integrators, implementation of variable FIR filters based on the above said window newlinefunctions and variable linear phase direct digital IIR filter using a novel mathematical derivation newlineof the fractional Fourier transform. Fractional Fourier transform(FrFT) is a tool to analyze the newlinesignals on time frequency domains is presented. Discussions on window analysis using proposed newlineclosed form FrFT, combination window provides spectral values of all other window functions newlinewith single equation and its merits. However, the proposed Differentiator provides better results newlinethan its contemporary works. The variable FIR filter has been used to tune their frequency newlinecharacteristics and finally we proposed IIR filters frequency characteristics with linear phase and newlinealso masking of images with 2-D window function is presented as an application of FrFT. In this work we present the efficiency of the filters and adjudged basing upon computation cost and newlinefrequency range possibilities. newline