Design Of Oversampled NPR DFT Filterbanks

Oversampled filter banks have gained increased attention in recent years.Such interests can be attributed to many advantages of oversampled systems,such as more degrees of design freedom,improved noise resistance and noise shaping ability,more redundancy.This paper presents a new method for the design of oversampled nearly perfect reconstruction DFT modulated filter banks with different analysis and synthesis prototype filters. This paper mainly consist of two parts.The first aspect is contributed to the design of oversampled nearly perfect reconstruction DFT modulated filter banks. The design method aims at minimizing aliasing in the subband signals as well as minimizing resisual aliasing, system distortions in the reconstructed output signal. Due to usage of the two prototype filters, there exists more available degrees of freedom for optimal design.The passband requirements of analysis filter bank and synthesis filter bank can be flexibly adjusted since simple constraints about the passband flatness in our method. The proposed method can achieve better performance than the traditional methods, which are also verified by the numerical examples.The other aspect is devoted to the design of linear phase nearly perfect reconstruction oversampled DFT modulated filter banks with different analysis and synthesis prototype filters. A simple linear phase construct can be efficiently implemented using the oversamoled DFT modulated filter banks.The proposed method is similar to the front technique. Additionally,due to the linear phase, constraints on the system become simpler and the design algorithm is significantly simplified.And the examples verified that the analysis and synthesis prototype filters with the linear phase constrains show a little loss in perfanmence compare with those without this property.