Free DSP Books on the Internet

Rick Lyons

While surfing the "net" I have occasionally encountered signal processing books whose chapters could be downloaded to my computer. I started keeping a list of those books and, over the years, that list has grown to over forty books. Perhaps the...

Handling Spectral Inversion in Baseband Processing

Eric Jacobsen

The problem of "spectral inversion" comes up fairly frequently in the context of signal processing for communication systems. In short, "spectral inversion" is the reversal of the orientation of the signal bandwidth with...

An Interesting Fourier Transform - 1/f Noise

Steve Smith

Power law functions are common in science and engineering. A surprising property is that the Fourier transform of a power law is also a power law. But this is only the start- there are many interesting features that soon become apparent. This may...

Spectral Flipping Around Signal Center Frequency

Rick Lyons

Most of us are familiar with the process of flipping the spectrum (spectral inversion) of a real signal by multiplying that signal's time samples by (-1)n. In that process the center of spectral rotation is fs/4, where fs is the signal's sample...

A Differentiator With a Difference

Rick Lyons

Some time ago I was studying various digital differentiating networks, i.e., networks that approximate the process of taking the derivative of a discrete time-domain sequence. By "studying" I mean that I was experimenting with various...

Delay estimation by FFT

Markus Nentwig

Given x=sig(t) and y=ref(t), returns [c, ref(t+delta), delta)] = fitSignal(y, x);:Estimates and corrects delay and scaling factor between two signals Code snippet This article relates to the Matlab / Octave code snippet: Delay estimation with...

Polyphase filter / Farrows interpolation

Markus Nentwig

Hello, this article is meant to give a quick overview over polyphase filtering and Farrows interpolation. A good reference with more depth is for example Fred Harris' paper: The task is as...

Hello and Introduction

Parth Vakil

Hello all.I would like to take this chance to talk a little about what I am going to try and do in this blog. While working in the field, I have come across some interesting techniques. It has, at times, taken some time and effort to understand...