{"id":32,"date":"2010-10-29T16:21:46","date_gmt":"2010-10-29T16:21:46","guid":{"rendered":"http:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=32"},"modified":"2023-02-21T16:29:11","modified_gmt":"2023-02-21T16:29:11","slug":"coding-theory","status":"publish","type":"page","link":"https:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=32","title":{"rendered":"Coding Theory"},"content":{"rendered":"<p><!--LEFT COLUMN--><\/p>\n<div style=\"float: left; width: 46%;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-272\" src=\"http:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/11\/binary-code.jpg\" alt=\"\" width=\"317\" height=\"448\" srcset=\"https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/11\/binary-code.jpg 317w, https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/11\/binary-code-212x300.jpg 212w\" sizes=\"auto, (max-width: 317px) 100vw, 317px\" \/><\/p>\n<h4 style=\"text-align:center\"><em>A main goal of coding theory is the design of coding methods that achieve error control: detect and correct errors in received and stored data.<\/em><\/h4>\n<\/div>\n<p><!--END--><\/p>\n<p><!--RIGHT COLUMN--><\/p>\n<div style=\"float:right; width: 40%;\">\n<h2><a style=\"text-decoration:none;\" href=\"http:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=217\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-black-color\">Projects<\/mark><\/a><\/h2>\n<ul>\n<li><em><a style=\"text-decoration:none;\" href=\"http:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=217#BalFunc\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-black-color\">Balanced Functions<\/mark><\/a><\/em><\/li>\n<\/ul>\n<ul>\n<li><em><a style=\"text-decoration:none;\" href=\"http:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=217#TurCod\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-black-color\">Turbo Codes<\/mark><\/a><\/em><\/li>\n<\/ul>\n<ul>\n<li><em><a style=\"text-decoration:none;\" href=\"http:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=217#other\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-black-color\">Other<\/mark><\/a><\/em><\/li>\n<\/ul>\n<\/div>\n<p><!--END--><\/p>\n<hr \/>\n<p><strong>Coding Theory<\/strong> is the study of methods for efficient and accurate transmission or storage of information. It started out as a mathematical and engineering subject with the paper &#8220;A Mathematical Theory of Communication&#8221; by <em>Claude Shannon<\/em> in 1948.<\/p>\n<p>Consider the next image which represents a general information transmission system:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-765\" src=\"http:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/new_General-Information-Transmission-System-1024x284.jpg\" alt=\"\" width=\"640\" height=\"177\" srcset=\"https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/new_General-Information-Transmission-System-1024x284.jpg 1024w, https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/new_General-Information-Transmission-System-300x83.jpg 300w, https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/new_General-Information-Transmission-System.jpg 1094w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p>The information that is transmitted or stored is called the <em>message<\/em>. A <em>channel<\/em> is the physical medium through which the information is transmitted or where it is stored. Telephone lines and the atmosphere are examples of channels. An <em>encoder<\/em> adds redundancy to the message by constructing codewords so that, when received, the <em>decoder<\/em> can detect and correct errors. The <em>code<\/em> is the set of all codewords.<\/p>\n<h3><em><strong>Most importantly, Coding Theory deals with the problem of detecting and correcting transmission errors caused by disturbances on the channel called noise.<\/strong><\/em><\/h3>\n<p>Noise may be caused by sunspots, lighting, folds in magnetic tape, meteor showers, competing telephone messages, random radio disturbance, or many other things.<\/p>\n<p><strong>Example<\/strong>: Suppose we want to send the message &#8220;1&#8221;. We can encode this by repeating it, say 3 times, so the codeword would be &#8220;111&#8221;. Now suppose the codeword is sent through a channel and &#8220;101&#8221; was received. The decoder knows that the codeword has the message repeated 3 times and decides on the message based on the received symbol that occurred most frequently.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-764\" title=\"example\" src=\"http:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/example.jpg\" alt=\"\" width=\"939\" height=\"275\" srcset=\"https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/example.jpg 939w, https:\/\/ccom.uprrp.edu\/~labemmy\/Wordpress\/wp-content\/uploads\/2010\/10\/example-300x87.jpg 300w\" sizes=\"auto, (max-width: 939px) 100vw, 939px\" \/><\/p>\n<h3><em><strong>The most common applications for Coding Theory include:<\/strong><\/em><\/h3>\n<ul>\n<li> transmission of data (telephone lines, internet ,networks)<\/li>\n<li> wireless communication<\/li>\n<li> communication with deep space exploration crafts (Mariner, Voyager, etc. \u2013 the most important early application)<\/li>\n<li> storing\/retrieving information in computer memory<\/li>\n<li> storing\/retrieving audio\/video information (CDs, DVDs and Blu-Ray disks)<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>A main goal of coding theory is the design of coding methods that achieve error control: detect and correct errors in received and stored data. Projects Balanced Functions Turbo Codes Other Coding Theory is the study of methods for efficient &hellip; <a href=\"https:\/\/ccom.uprrp.edu\/~labemmy\/?page_id=32\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1037,"menu_order":5,"comment_status":"closed","ping_status":"closed","template":"onecolumn-page.php","meta":{"footnotes":""},"class_list":["post-32","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/pages\/32","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=32"}],"version-history":[{"count":104,"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/pages\/32\/revisions"}],"predecessor-version":[{"id":2105,"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/pages\/32\/revisions\/2105"}],"up":[{"embeddable":true,"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=\/wp\/v2\/pages\/1037"}],"wp:attachment":[{"href":"https:\/\/ccom.uprrp.edu\/~labemmy\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=32"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}