1. Introduction

     Sampling is essential to convert analog signal to digital signal. In this page, I would specifically
explain about downsampling. In digital signal processing, the decimator performs decimation, which is
downsampling a signal. In other words, when a digital signal is downsampled, the signal's sampling
rate would be reduced.
Intro1.jpg


2. Derivation


Sdf21le.jpg
Derivation2.jpg
Derivaa3.jpg 


3. Example


If) D = 2
Ex123.jpg
Ex4342e.jpg
Ex3g3le.jpg
Exam134gggge.jpg


4. Conclusion


      Downsampling reduces the magnitude by a factor of D, and increases the width of signals by D in the frequency domain. Moreover, it repeats it's signals every 2π and to prevent aliasing, decimator needs a lowpass filter before the downsampling.


Questions and comments

If you have any questions, comments, etc. please post them on this page.

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood