DESIGN OF PERFECT RECONSTRUCTION FIR FILTER BANKS USING DFT MODULATION

In this paper, we present a method for designing perfect reconstructio n (PR) FIR filter banks by discrete Fourier transform modulation (DFT modulation). In previous work, cosine-modulated PR filter banks were s hown to be easy to design and capable of fast processing. But this met hod is inconvenient because of its restriction of filter length. In ou r new approach, filter banks are implemented by DFT modulation of the prototype filter with complex coefficients, yielding some advantages o ver the previous work. Our proposed filter banks are a new formulation of modulated filter bank design and an alternative implementation of cosine-modulated filter banks. We propose an optimization technique us ing the Lagrange-Newton method. The effectiveness of the proposed meth od is demonstrated with design examples.