Design of perfect reconstruction FIR filter banks using DFT-modulation

In this paper, we present a design method of perfect reconstruction (PR) FIR filter banks by discrete Fourier transform modulation (DFT-modulation). In the previous work, the implementation of cosine-modulated PR filter banks is shown to be easy to design and capable of fast processing, but this method is a little bit inconvenient because of its restriction of the filter length. In our new approach filter banks are implemented by DFT-modulation of prototype filter with complex coefficients and has some advantages over the previous work. Furthermore, we propose a optimization method using Lagrange-Newton method. In the last part we show design example and this method effective.