Signal Processing

How to Create a Configurable Filter Using a Kaiser Window

Figure 3. Frequency response of a low-pass filter with a Kaiser window; A=60.

This article explains how to create a windowed-sinc filter with a Kaiser (or Kaiser-Bessel) window. The windowed-sinc filters in previous articles typically had two parameters, the cutoff frequency and the transition bandwidth (or rolloff). With a Kaiser window, there is a third input parameter, the ripple. For the specific case of the Kaiser window, the same… read more

Submitted on 26 December 2016

Low-Pass Single-Pole IIR Filter

Figure 1. Impulse response of a low-pass single-pole filter.

The low-pass single-pole IIR filter is a very useful tool to have in your DSP toolbox. Its performance in the frequency domain may not be stellar, but it is very computationally efficient. A low-pass single-pole IIR filter has a single design parameter, which is the decay value d. It is customary to define parameters… read more

Submitted on 14 February 2016

Variations on the Moving Average

Figure 2. Impulse (left), step (middle), and frequency (right) responses for the triangular window.

The moving-average filter is a strong performer in the time domain, but not in the frequency domain. For those cases where you have to work with data for which both domains are important, there are “weighted” versions of the moving average that are… read more

Submitted on 1 February 2016