Design of linear-phase oversampled nonuniform filter banks with arbitrary integer sampling factors

Abstract

In this paper, we extend the partial modulation technique to obtain the highly desired linear-phase (LP) characteristics of oversampled nonuniform filter banks (NUFBs), which makes it possible to design LP oversampled NUFBs based on the efficient modulation technique. Further for the subbands with sampling factors violating the guard band constraint, a phase modification structure is also proposed to avoid uneliminable large aliasing and meanwhile maintain the LP characteristics of analysis/synthesis filters, realizing arbitrary integer decimation. By using the proposed algorithm, the constraints on the LP oversampled NUFB design are simplified into those only imposed on several prototype filters, largely reducing the design complexity. As demonstrated by examples, the proposed algorithm can achieve LP oversampled NUFBs with arbitrary integer decimation in a simple and efficient way.