Signal Processing

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

The Moving Average as a Filter

Figure 1. Smoothing with a moving average filter.

The moving average is often used for smoothing data in the presence of noise. The simple moving average is not always recognized as the Finite Impulse Response (FIR) filter that it is, while it is actually one of the most common filters in signal processing. Treating it as a filter allows… read more

Submitted on 4 December 2015

Why Clipping Should Be Avoided

Figure 2. Clipped sine.

Before you can digitally process an analog (i.e., real-world) signal, you have to convert it to a digital form by sampling it. A very important aspect of this conversion is that you should avoid clipping the original signal. Clipping happens when… read more

Submitted on 16 February 2015

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