8-Channel Biorthogonal Cosine Modulated Filter Bank

This document presents the implementation of an 8-channel biorthogonal cosine modulated filter bank for filtering applications. The filter bank operates at a sampling frequency of Fs: 20,000 Hz and utilizes a low-pass prototype design with a passband frequency of 625 Hz and 80 dB stopband attenuation. The implementation employs 512-tap filter coefficients to achieve the desired frequency response characteristics. The design methodology involves creating a low-pass prototype filter using optimized coefficient calculation algorithms, which is then modulated using cosine functions to generate the 8 parallel filter channels. The biorthogonal structure ensures perfect reconstruction properties while maintaining efficient computational performance. This filter bank configuration is particularly suitable for multi-rate signal processing applications where frequency band segmentation and reconstruction are required. Key implementation aspects include careful coefficient quantization to maintain the 80 dB attenuation specification and efficient polyphase decomposition structures to optimize computational efficiency. The 512-tap length provides sufficient frequency resolution while balancing computational complexity for real-time processing scenarios.