Difference between revisions of "Information Theory"

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Seit den ersten Anfängen der Nachrichtenübertragung als naturwissenschaftliche Disziplin war es das Bestreben vieler Ingenieure und Mathematiker, ein quantitatives Maß für die in einer Nachricht enthaltene Information zu finden. Hierbei soll unter „Information“ ganz allgemein die Kenntnis über irgend etwas verstanden werden, während wir im folgenden eine „Nachricht“ stets als eine Zusammenstellung von Symbolen und/oder Zuständen betrachten, die zur Übermittlung von Information dient. Die (abstrakte) Information wird durch die (konkrete) Nachricht mitgeteilt und kann in vielerlei Hinsicht als Interpretation einer Nachricht aufgefasst werden.
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===Brief summary===
  
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{{BlueBox|TEXT=From the earliest beginnings of message transmission as an engineering discipline,  it has been the endeavour of many engineers and mathematicians  to find a quantitative measure for the
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*contained  $\rm information$  $($quite generally:  »the knowledge about something«$)$
  
Claude Elwood Shannon gelang es 1948, eine in sich konsistente Theorie über den Informationsgehalt von Nachrichten zu begründen, die zu ihrer Zeit revolutionär war und ein neues, bis heute hochaktuelles Wissenschaftsgebiet kreierte: die nach ihm benannte Shannonsche Informationstheorie.  
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*in a  $\rm message$  $($here we mean  »a collection of symbols and/or states»$)$.
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The  $($abstract$)$  information is communicated by the  $($concrete$)$  message and can be conceived as the interpretation of a message.
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[https://en.wikipedia.org/wiki/Claude_Shannon '''Claude Elwood Shannon''']  succeeded in 1948,  in establishing a consistent theory about the information content of messages,  which was revolutionary in its time and created a new,  still highly topical field of science:   »'''Shannon's information theory«'''  named after him.
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This is what the fourth book in the  $\rm LNTwww$ series deals with,  in particular:
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# Entropy of discrete-value sources with and without memory,  as well as natural message sources:  Definition,  meaning and computational possibilities.
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# Source coding and data compression,  especially the   »Lempel–Ziv–Welch method«   and   »Huffman's entropy encoding«. 
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# Various entropies of two-dimensional discrete-value random quantities.  Mutual information and channel capacity.  Application to digital signal transmission.   
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# Discrete-value information theory.  Differential entropy.  AWGN channel capacity with continuous-valued as well as discrete-valued input.
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⇒   First a  »'''content overview'''«  on the basis of the  »'''four main chapters'''«  with a total of  »'''13 individual chapters'''«  and  »'''106 sections'''«:}}
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===Content===
  
===Inhalt===
 
 
{{Collapsible-Kopf}}
 
{{Collapsible-Kopf}}
{{Collapse1| header=Entropie wertdiskreter Nachrichtenquellen
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{{Collapse1| header=Entropy of Discrete Sources
 
| submenu=  
 
| submenu=  
*[[/Gedächtnislose Nachrichtenquellen/]]
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*[[/Discrete Memoryless Sources/]]
*[[/Nachrichtenquellen mit Gedächtnis/]]
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*[[/Discrete Sources with Memory/]]
*[[/Natürliche wertdiskrete Nachrichtenquellen/]]
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*[[/Natural Discrete Sources/]]
 
}}
 
}}
{{Collapse2 | header=Quellencodierung - Datenkomprimierung
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{{Collapse2 | header=Source Coding - Data Compression
 
|submenu=
 
|submenu=
*[[/Allgemeine Beschreibung/]]
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*[[/General Description/]]
*[[/Komprimierung nach Lempel, Ziv und Welch/]]
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*[[/Compression According to Lempel, Ziv and Welch/]]
*[[/Entropiecodierung nach Huffman/]]
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*[[/Entropy Coding According to Huffman/]]
*[[/Weitere Quellencodierverfahren/]]
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*[[/Further Source Coding Methods/]]
 
}}
 
}}
{{Collapse3 | header=Information zwischen zwei wertdiskreten Zufallsgrößen
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{{Collapse3 | header=Mutual Information Between Two Discrete Random Variables
 
|submenu=
 
|submenu=
*[[/Einige Vorbemerkungen zu zweidimensionalen Zufallsgrößen/]]
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*[[/Some Preliminary Remarks on Two-Dimensional Random Variables/]]
*[[/Verschiedene Entropien zweidimensionaler Zufallsgrößen/]]
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*[[/Different Entropy Measures of Two-Dimensional Random Variables/]]
*[[/Anwendung auf die Digitalsignalübertragung/]]
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*[[/Application to Digital Signal Transmission/]]
 
}}
 
}}
{{Collapse4 | header=Wertkontinuierliche Informationstheorie
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{{Collapse4 | header=Information Theory for Continuous Random Variables
 
|submenu=
 
|submenu=
*[[/Differentielle Entropie/]]
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*[[/Differential Entropy/]]
*[[/AWGN–Kanalkapazität bei wertkontinuierlichem Eingang/]]
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*[[/AWGN Channel Capacity for Continuous-Valued Input/]]
*[[/AWGN–Kanalkapazität bei wertdiskretem Eingang/]]
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*[[/AWGN Channel Capacity for Discrete-Valued Input/]]
 
}}
 
}}
 
{{Collapsible-Fuß}}
 
{{Collapsible-Fuß}}
  
Dieses Lehrbuch wurde im Mai 2011 begonnen und im Sommer 2015 fertiggestellt.
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===Exercises and multimedia===
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{{BlaueBox|TEXT=
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In addition to these theory pages,  we also offer exercises and multimedia modules on this topic,  which could help to clarify the teaching material:
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$(1)$    [https://en.lntwww.de/Category:Information_Theory:_Exercises $\text{Exercises}$]
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$(2)$    [[LNTwww:Learning_videos_to_"Information_Theory"|$\text{Learning videos}$]]
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$(3)$    [[LNTwww:Applets_to_"Information_Theory"|$\text{Applets}$]] }}
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===Further links===
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{{BlaueBox|TEXT=
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$(4)$    [[LNTwww:Bibliography_to_"Information_Theory"|$\text{Bibliography}$]]
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$(5)$    [[LNTwww:Imprint_for_the_book_"Information_Theory"|$\text{Impressum}$]]}}
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<br><br>
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Latest revision as of 17:50, 31 December 2023

Brief summary

From the earliest beginnings of message transmission as an engineering discipline,  it has been the endeavour of many engineers and mathematicians  to find a quantitative measure for the

  • contained  $\rm information$  $($quite generally:  »the knowledge about something«$)$
  • in a  $\rm message$  $($here we mean  »a collection of symbols and/or states»$)$.


The  $($abstract$)$  information is communicated by the  $($concrete$)$  message and can be conceived as the interpretation of a message.

Claude Elwood Shannon  succeeded in 1948,  in establishing a consistent theory about the information content of messages,  which was revolutionary in its time and created a new,  still highly topical field of science:  »Shannon's information theory«  named after him.

This is what the fourth book in the  $\rm LNTwww$ series deals with,  in particular:

  1. Entropy of discrete-value sources with and without memory,  as well as natural message sources:  Definition,  meaning and computational possibilities.
  2. Source coding and data compression,  especially the   »Lempel–Ziv–Welch method«   and   »Huffman's entropy encoding«.
  3. Various entropies of two-dimensional discrete-value random quantities.  Mutual information and channel capacity.  Application to digital signal transmission.
  4. Discrete-value information theory.  Differential entropy.  AWGN channel capacity with continuous-valued as well as discrete-valued input.


⇒   First a  »content overview«  on the basis of the  »four main chapters«  with a total of  »13 individual chapters«  and  »106 sections«:


Content

Exercises and multimedia

In addition to these theory pages,  we also offer exercises and multimedia modules on this topic,  which could help to clarify the teaching material:

$(1)$    $\text{Exercises}$

$(2)$    $\text{Learning videos}$

$(3)$    $\text{Applets}$ 


Further links