## Spectral Flipping Around Signal Center Frequency

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

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

●3 commentsGiven 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

●5 commentsHello, 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: http://www.signumconcepts.com/IP_center/paper018.pdf The task is as...

## Hello and Introduction

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...

## A Two Bin Exact Frequency Formula for a Pure Complex Tone in a DFT

●1 commentIntroduction This is an article to hopefully give a better understanding to the Discrete Fourier Transform (DFT) by deriving an exact formula for the frequency of a complex tone in a DFT. It is basically a parallel treatment to the real case...

## An s-Plane to z-Plane Mapping Example

While surfing around the Internet recently I encountered the 's-plane to z-plane mapping' diagram shown in Figure 1. At first I thought the diagram was neat because it's a good example of the old English idiom: "A picture is worth a thousand...

## New Comments System (please help me test it)

I thought it would take me a day or two to implement, it took almost two weeks...But here it is, the new comments systems for blogs, heavily inspired by the forum system I developed earlier this year. Which means that:You can easily add...

## Hello and Introduction

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...

## Blogging Tutorial

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...