Design of Linear Phase FIR Bandpass Filter Using fir1 Function with Various Window Methods

This project involves designing a linear phase FIR bandpass filter using MATLAB's fir1 function with the following specifications: stopband cutoff frequencies at 0.55π and 0.85π, passband cutoff frequencies at 0.65π and 0.75π, maximum passband attenuation of 0.2 dB, and minimum stopband attenuation of 42 dB. The implementation utilizes three different window functions for comparative analysis: Hanning window, Hamming window, and Blackman window. For each window method, the design process includes: 1. Calculating filter order based on attenuation requirements using empirical formulas 2. Generating window coefficients using MATLAB's window functions (hanning, hamming, blackman) 3. Applying fir1 with appropriate frequency normalization and window parameters 4. Extracting impulse response coefficients through filter coefficient analysis 5. Plotting magnitude frequency responses using freqz function with dB scaling Key implementation details: - Normalized frequency parameters are converted to linear frequency scale for fir1 input - Filter order estimation considers the transition bandwidth between passband and stopband - Window selection impacts side lobe attenuation and main lobe width trade-offs - Magnitude response plotting includes grid lines and axis labeling for clarity For each design case, the complete impulse response coefficients will be presented in tabular format, and corresponding magnitude frequency response plots will demonstrate filter performance characteristics including passband ripple and stopband attenuation levels.