Title :
Comments on “Closed Form Variable Fractional Time Delay Using FFT”
Author_Institution :
Fac. of Electron., Telecommun. & Inf., Gdansk Univ. of Technol., Gdansk, Poland
Abstract :
In this letter drawbacks of the aforementioned paper are pointed out. The proposed approach is improved with minor modifications of the discrete frequency response. This allows for design of fractional delay filters which are close to optimal and can be efficiently implemented in the frequency domain using the sliding DFT based structure. Alternatively, the derived equivalent closed form formulae for offset windows can be used to design filters in the time domain.
Keywords :
delay filters; delays; fast Fourier transforms; frequency response; frequency-domain analysis; time-domain analysis; FFT; closed-form variable fractional time delay; discrete frequency response; filter design; fractional delay filters; frequency domain; offset windows; sliding DFT-based structure; time domain; Computational efficiency; Delays; Discrete Fourier transforms; Frequency response; Frequency-domain analysis; Interpolation; Kernel; Fractional delay (FD) filter; window method;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2013.2265394
