PID Without a PhD

Tim Wescott

I both consult and teach in the area of digital control. Through both of these efforts, I have found that while there certainly are control problems that require all the expertise I can bring to bear, there are a great number of control problems...

Harmonic Notch Filter


My basement is covered with power lines and florescent lights which makes collecting ECG and EEG data  rather difficult due to the 60 cycle hum.  I found the following notch filter to work very well at eliminating the background signal...

A Useful Source of Signal Processing Information

Rick Lyons

I just discovered a useful web-based source of signal processing information that was new to me. I thought I'd share what I learned with the subscribers here on DSPRelated.com. The Home page of the web site that I found doesn't look at...

3 Good News

Stephane Boucher

Good News #1 Last week, I announced a new and ambitious reward program that will be funded by the new Vendors Directory. This week, I am happy to announce that we have our firsts two sponsors!  Quantum Leaps & Abelon Systems have...

Generating pink noise


In one of his most famous columns for Scientific American, Martin Gardner wrote about pink noise and its relation to fractal music.  The article was based on a 1978 paper by Voss and Clarke, which presents, among other things, a simple...

Exponential Smoothing with a Wrinkle

Cedron Dawg

Introduction This is an article to hopefully give a better understanding to the Discrete Fourier Transform (DFT) by providing a set of preprocessing filters to improve the resolution of the DFT. Because of the exponential nature of...

Discrete-Time PLLs, Part 1: Basics

Reza Ameli

In this series of tutorials on discrete-time PLLs we will be focusing on Phase-Locked Loops that can be implemented in discrete-time signal proessors such as FPGAs, DSPs and of course, MATLAB.

Analytic Signal


In communication theory and modulation theory we always deal with two phases: In-phase (I) and Quadrature-phase (Q). The question that I will discuss in this blog is that why we use two phases and not more.

Blogging Tutorial

Stephane Boucher

This article will be updated on a regular basis based on your questions and feedback. Creating a new blog post Make sure your are logged in Click on 'Create new blog post' Although the online editor works pretty well and...

Four Ways to Compute an Inverse FFT Using the Forward FFT Algorithm

Rick Lyons

If you need to compute inverse fast Fourier transforms (inverse FFTs) but you only have forward FFT software (or forward FFT FPGA cores) available to you, below are four ways to solve your problem. Preliminaries To define what we're...