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| {{underlinked|date=November 2012}}
| | Her name is Felicidad Ahmad. What he truly enjoys performing is to play handball but he is having difficulties to find time for it. Bookkeeping is what I do for a residing. Delaware has usually been my living location and will never move.<br><br>Feel free to surf to my blog post - [http://89.1.13.189/index.php?mod=users&action=view&id=63366 http://89.1.13.189/index.php?mod=users&action=view&id=63366] |
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| In [[computer science]], '''repeat-accumulate codes''' (RA codes) are a low complexity class of [[error-correcting code]]s. They were devised so that their [[ensemble weight distributions]] are easy to derive. RA codes were introduced by Divsalar ''et al.''
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| In an RA code, an [[information block]] of length <math>{N}</math> is repeated <math>{q}</math> times, scrambled by an [[interleaver]] of size <math>{qN}</math>, and then encoded by a rate 1 [[accumulator]]. The accumulator can be viewed as a truncated rate 1 [[recursive]] convolutional encoder with transfer function <math>{1/(1 + D)}</math>, but Divsalar ''et al.'' prefer to think of it as a block code whose input block <math>{(z_1, \ldots , z_n)}</math> and output block <math>{(x_1, \ldots , x_n)}</math> are related by the formula <math>{x_1 = z_1}</math> and <math>x_i = x_{i-1}+z_i</math> for <math>i > 1</math>. The encoding time for RA codes is linear and their rate is <math>1/q</math>. They are nonsystematic.
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| == References == | |
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| * D. Divsalar, H. Jin, and R. J. McEliece. "Coding theorems for ‘turbo-like’ codes." ''Proc. 36th Allerton Conf. on Communication, Control and Computing, Allerton, Illinois'', Sept. 1998, pp. 201–210.
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| == External links == | |
| * [http://www.cambridge.org/gb/knowledge/isbn/item2711886/?site_locale=en_GB Iterative Error Correction: Turbo, Low-Density Parity-Check, and Repeat-Accumulate Codes]
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| [[Category:Error detection and correction]]
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| [[Category:Computer languages]]
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Latest revision as of 22:20, 15 November 2014
Her name is Felicidad Ahmad. What he truly enjoys performing is to play handball but he is having difficulties to find time for it. Bookkeeping is what I do for a residing. Delaware has usually been my living location and will never move.
Feel free to surf to my blog post - http://89.1.13.189/index.php?mod=users&action=view&id=63366