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Introduction to Information Theory

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Communications Model   ::   Fundamental Concept   ::   Channel Models

Some simple discrete channel models

The binary symmetric channel:

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The parameter p is the probability of error. For many channels we can explicilty compute p. For example, for BPSK

\begin{displaymath}p = Q\left(\sqrt{\frac{2E_b}{N_0}}\right) \end{displaymath}

The channel is characterized by its conditional probabilities:

\begin{displaymath}P(Y=0\vert X=0) = 1-p\qquad P(Y=1\vert X=0) = p \end{displaymath}

\begin{displaymath}P(Y=0\vert X=1) = p\qquad P(Y=1\vert X=1) = 1-p \end{displaymath}

Copyright 2008, by the Contributing Authors. Cite/attribute Resource. admin. (2006, May 17). Introduction to Information Theory. Retrieved November 24, 2009, from Free Online Course Materials — USU OpenCourseWare Web site: http://ocw.usu.edu/Electrical_and_Computer_Engineering/Information_Theory/lecture1_4.htm. This work is licensed under a Creative Commons License. Creative Commons License
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