Comments on “Closed Form Variable Fractional Time Delay Using FFT”
Marek Blok · IEEE Signal Processing Letters · 2013
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.