Window Method FIR Low Pass Filter Design MATLAB Program

This MATLAB program demonstrates the window method for designing low-pass FIR (Finite Impulse Response) filters. The window method is a fundamental approach in digital filter design where we first specify an ideal filter response and then apply a window function to truncate the infinite impulse response to a finite length. The program showcases how to select appropriate window functions (such as Hamming, Hanning, or Blackman windows) and filter parameters to meet specific frequency response requirements. In MATLAB implementation, key functions like fir1() are utilized, which automatically handles the window-based FIR design process by accepting parameters such as filter order, cutoff frequency, and window type. The algorithm involves calculating the ideal filter coefficients, applying the selected window function to reduce spectral leakage, and verifying the resulting frequency response using freqz(). This program provides practical insights into the principles and methodology of window-based FIR filter design, including trade-offs between main lobe width and side lobe attenuation in different window functions.