Minimization maximum design method for alternating DFT modulation filter banks

Abstract

The invention discloses a minimization maximum design method for alternating DFT modulation filter banks. The requirement for oversampling of reconstructed characteristics and frequency characteristics of the DFT modulation filter banks is converted into a function relative to prototype filter coefficients, then a design problem of alternating the DFT modulation filter tanks is converted into a constrained optimization problem, and finally minimization maximum algorithm is adopted for obtaining the optimal coefficient of the prototype filter. An aliasing component compensation mode is introduced into the design of oversampling of the DFT modulation filter banks for the first time for controlling aliasing errors, so that aliasing errors are effectively constrained, the reconstruction performance is improved, and the high-aliasing problem caused by stopband attenuation is avoided.

Description

technical field [0001] The invention belongs to the field of multi-rate signal processing, and in particular relates to a minimization-maximum design method of an alternating DFT (discrete Fourier transform) modulation filter bank. Background technique [0002] Multi-rate filter banks are widely used in speech signal processing, image processing, radar signal processing and so on. As a special kind of filter bank, DFT modulated filter bank has received special attention because of its simple design and low implementation cost. In recent years, some scholars have constructed a new class of DFT modulated filter banks, called alternating DFT modulated filter banks. In this type of filter bank, the adjacent sub-band filters are obtained by DFT modulation of different prototype filters, so the shapes of their amplitude responses are different, which is beneficial to the suppression of aliasing distortion. Due to the contradiction between aliasing distortion cancellation and hig...

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Problems solved by technology

[0004] What the present invention is to solve is the problem that the frequency characteristics and reconstruction characteristics of the existing over-sampled alternating DFT modulation filter banks are difficult to effectively control simultaneously, and a minimization and maximum design method for alternating DFT modulation filter banks is provided

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