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1. Introduction  
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= '''1. Introduction'''  =
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Sampling is essential to convert analog signal to digital signal. In this page, I would specifically explain about downsampling.  
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===== &nbsp;&nbsp;&nbsp;&nbsp; Sampling is essential to convert analog signal to digital signal. In this page, I would specifically<br>explain about downsampling. In digital signal processing, the decimator performs decimation, which is<br>downsampling a signal. In other words, when a digital signal is downsampled, the signal's sampling<br>rate would be reduced. =====
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In digital signal processing, the decimator performs decimation, which is downsampling a signal. In other words, when a digital
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===== [[Image:Intro1.jpg]] =====
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signal is downsampled, the signal's sampling rate would be reduced.
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= <br> '''2. Derivation'''  =
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<br> [[Image:Sdf21le.jpg]] <br> [[Image:Derivation2.jpg]] <br> [[Image:Derivaa3.jpg]]&nbsp;
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= '''<br> 3. Example'''  =
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= <br> If) D = 2 <br> [[Image:Ex123.jpg]]<br> [[Image:Ex4342e.jpg]]<br> [[Image:Ex3g3le.jpg]] <br> [[Image:Exam134gggge.jpg]] <br>  =
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= <br> '''4. Conclusion'''  =
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===== <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 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.  =====
  
[[Image:intro1.jpg]]
 
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2. Derivation
 
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[[Image:derivation1.jpg]]
 
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[[Image:derivation2.jpg]]
 
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[[Image:derivation3.jpg]]
 
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3. Example
 
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If) D = 2
 
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[[Image:mydrawing1.jpg]]
 
4. Conclusion
 
 
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==[[Downsampling_Soonho_Kwon_slecture_review|Questions and comments]]==
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If you have any questions, comments, etc. please post them on [[Downsampling_Soonho_Kwon_slecture_review|this page]].

Latest revision as of 06:07, 13 October 2014

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.

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Prof. Dan Fleetwood