A high performance continuous data flow filter using sliding discrete Fourier transform (DFT) and one point inverse DFT

Abstract

This paper presents a high performance frequency domain filter implementation for a moving window-type processing. The computational structure consists of three stages: a sliding discrete Fourier transform (SDFT) for a vectorized updating of the DFT; a frequency domain filter; and a one-point inverse discrete Fourier transform (IDFT). The total computation required for generating one filtered output point is 2/spl times/N multiplications (N is the frequency window length) and 3/spl times/N additions compared to 2/spl times/N/spl times/log/sub 2/N multiplications and additions if using FFT and IFFT. The proposed structure also has the advantage of being parallel in nature and can be used in various real-time frequency processing, continuous data flow, single or multiple channel applications.