Periodic Sequences Modulated Filter Banks
Xi-Lin Li · IEEE Signal Processing Letters · 2018
This letter studies nearly perfect reconstruction periodic sequences modulated filter banks, which includes many useful examples, e.g., the discrete Fourier transform (DFT), generalized DFT, and cosine-modulated ones. A general framework is developed to meet arbitrary, but feasible design constraints, e.g., length of filters, system delay, decimation ratio, phase linearity, etc., and it also reveals new design freedoms, i.e., phase shifts in the modulation sequences. An efficient Newton algorithm is proposed, and a MATLAB/Octave package with diverse design examples is provided. Numerical results show that better designs can be obtained by searching for the solutions in a larger space than the one from traditional frameworks.