When researching what to include in The Moving Average as a Filter and Variations on the Moving Average, I came across a lot of references to applications in the financial sector. This is not my forte, but, just for fun, I gave a few of the moving averages that are used there the same treatment as the filters in…
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…
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…
After introducing several types of filters in previous articles, this article compares their performance in the time and frequency domain. This is important because the choice of filter is strongly influenced by the domain in which the useful information in your signal is situated…
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…
I have just posted a major update of my filter design tool. Go to the tool. The new version of the tool allows you to change the sampling rate away from the default of using normalized frequency (but beware of the caveats). Finally, you can also…
Frequency response plots are often shown with normalized frequency on the X-axis. This sometimes confuses people. The normalized frequency is computed by dividing the true frequency by the sampling rate. Hence, the sampling rate itself has…
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…
After explaining how amplitude modulation works, the next step is Frequency Modulation (FM), which you might be more familiar with, since it is widely used for radio broadcasting. In practice, a carrier for FM broadcast radio would have…
Using modulation in radio communications is unavoidable. The simplest modulation technique is Amplitude Modulation (AM), where the amplitude of a carrier is varied according to the message that is to be transmitted. A carrier is…