An efficient closed-form design method for cosine-modulated filter banks using window functions

An efficient closed-form method for designing M-channel cosine-modulated filter banks with prescribed stopband attenuation and channel overlap is proposed. The method employs the window technique for the prototype filter design and is based on empirical formulas that give the filter length and the window parameters that would satisfy the prescribed specifications. When compared with iterative methods, the proposed method significantly reduces the computational cost associated with the design making it a suitable candidate for applications where the design must be carried out in real or quasi-real time. Applications of the proposed method in the area of subband processing of speech, audio, and ECG signals are considered.