Design of effective window function for FIR filters

Abstract

In this paper, we design new window finction which is product of hamming and gaussian window and it has better performance compared to the several commonly used windows. Performance comparison of the proposed window with the Hamming, Blackman, Gaussian, and Kaiser windows shows that, for the same window length, if the proposed window has the same main lobe width as the other windows, then it offers less side lobe peak. The average reduction in the side lobe peak of the proposed window compared to that of the Hamming, Blackman, Gaussian, and kaiser windows is −19.4 dB, −3.6 dB, −4.5 dB, and −2.7 dB, respectively. It is obvious that, in the case of side lobe peak, the proposed window is also better than Bartlett and Hanning windows. The low pass FIR filter designed using the new window achieves less ripple ratio compared to the filters obtained using the Hamming, Blackman, Gaussian, and kaiser windows respectively, which confirms the better performance of the proposed window.