Mathematics of the Discrete Fourier Transform (DFT)



<< Previous page  TOC  INDEX  Next page >>

Decimation Operator



Definition: Decimation by $L$ is defined as taking every $L$th sample, starting with sample $0$:

\

The $\ operator maps a length $N=LM$ signal down to a length $M$signal. It is the inverse of the $\ operator (but not vice versa), i.e.,

\



The stretch and decimation operations do not commute because they are linear time-varying operators. They can be modeled using time-varying switches controlled by the sample index $n$.

Figure:Illustration of $\. The white-filled circles indicate the retained samples while the black-filled circles indicate the discarded samples.
\

An example of $\ is shown in Fig. 8.8. The example is

\

<< Previous page  TOC  INDEX  Next page >>

Back to Hardware Guides
"Music 320 Background Reader" by Julius O. Smith III, (Course Background Reader, Music 320). Copyright © 2001-01-02 by Julius O. Smith III. - Center for Computer Research in Music and Acoustics (CCRMA), Department of Electrical Engineering, Stanford University. This is a modified HTML version reproduced by permission.
| TXT | TXT+
Unless otherwise indicated, the contents of this site are copyright © Nicola Asuni - Tecnick.com s.r.l.
Tecnick.com s.r.l. - Sede Legale: Via Della Pace, 11 – 09044 – Quartucciu (CA) – ITALY - Capitale Sociale € 10.000,00 i.v. - P. IVA e C.F.: 02574420929 - C.C.I.A.A.: CA-2000-19195 - R.E.A.: 208980

Powered by Tecnick.com AIOCP (All In One Control Panel) GetJava Download Button
 
Technick.net - Tons of Hardware Information





Bookmark and Share