An efficient Quadrature Mirror Filter design and its applications in audio signal processing

A proficient approach to the design of Quadrature Mirror Filter (QMF) Bank is studied and an algorithm is offered for straightforward accomplishment of QMF bank with near perfect reconstruction. Objective function is built upon perfect reconstruction condition. The cutoff frequency is repetitively varied to adjust the filter coefficients using the anticipated algorithm and reconstruction error is minimized. Using the optimal value of cutoff frequency the prototype filter is designed and other filters of the bank is considered from that single prototype filter. Kaiser and Dolph-Chebyshev window functions are used to investigate the betterment of the design method. The performance of the projected design method are evaluated in terms of computation time required i.e. CPU time, Perfect Reconstruction Error (PRE), Magnitude Square Error (MSE) and Number of Iterations (NOI). The proposed algorithm is simple, easy to implement, and linearly converges to optimal solution. Finally, the sub-band decomposition of an audio signal is done using the filter bank.