Optimal Prototype Filters for Near-Perfect-Reconstruction Cosine-Modulated Nonuniform Filter Banks with Rational Sampling Factors
In this paper, we propose a simple design method of nonuniform filter banks (NUFBs) with rational sampling factors. The analysis filters are respectively generated by cosine modulating several prototype filters with certain matching condition. By following a cosine roll-off function of the transition bands of the stretched prototype filters, the overall system is approximately power complementary and therefore possesses the near-prefect-reconstruction (NPR) property. Further, due to the use of the Parks-McClellan algorithm in the filter design, no objective function in the optimization is explicitly required and optimal prototype filters for NPR cosine-modulated NUFBs can be obtained. Design examples along with comparisons show that the resulting filter banks are of high filter quality and the proposed method is of simplicity and effectiveness.
KeywordsFilter Bank Transition Band Magnitude Response Analysis Filter Prototype Filter
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