FIR filter design using a new window function

We present a new simple form window function with application to FIR filter design, which has superior performance compared to the several commonly used windows. The new window is almost equi-ripple. For sufficiently high orders, the proposed window has the main lobe width of roughly equal to that of the commonly used Hamming window, while featuring 5.6 ~ 12 dB smaller side lobe peak. For lower window lengths, the performance of Hamming window is degraded, while the new window maintains its maximum side lobe peak about -48 ~ -49.5 dB compared to -37 ~ -39 dB of Hamming window, and at the same time offers smaller main lobe width. Our results also show substantial performance improvement of the proposed window compared to the Gaussian, Kaiser, and Lanczos windows. A performance comparison of the proposed and Dolph-Chebyshev windows is also presented. The designed FIR filters confirm the efficiency of the new window.