{"id":34,"date":"2014-12-18T20:17:19","date_gmt":"2014-12-18T20:17:19","guid":{"rendered":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/?p=34"},"modified":"2014-12-20T14:27:22","modified_gmt":"2014-12-20T14:27:22","slug":"an-old-paper","status":"publish","type":"post","link":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/2014\/12\/18\/an-old-paper\/","title":{"rendered":"De-mapping Equations in &#8220;Advanced Modulation and Coding&#8221;"},"content":{"rendered":"<p>I jointly teach the module entitled &#8220;Advanced Modulation and Coding&#8221; with Dr Martin Johnston. This module is offered to both our MSc and MEng students. Dr Johnston is in charge of the &#8220;coding&#8221; part, whereas I\u00a0teach the &#8220;modulation&#8221; part. You can download the lecture notes for my part by clicking on this link: <a href=\"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/files\/2014\/12\/EEE8003.pdf\">EEE8003<\/a>.<\/p>\n<p>The coursework for this module consists of a\u00a0Matlab assignment in which students have to\u00a0assess via Monte Carlo\u00a0computer simulations the error performance of several\u00a0coded modulation systems over both Gaussian and flat Rayleigh fading channels. The assignment questions can be found in the last pages of\u00a0the lecture notes.<\/p>\n<p>In the Matlab assignment, students are required at some stage to use a soft-decision Viterbi decoder in order to improve the error performance of the system. This can be done only if a de-mapping\u00a0function (also known as\u00a0a\u00a0&#8220;demapper&#8221;) is employed at the channel output. The purpose of the demapper\u00a0is to convert the channel estimates into estimates of the transmitted bits that can then be processed by\u00a0the soft-decision Viterbi decoder.<\/p>\n<p>Finding the equations to implement the de-mapping function is not an easy task. This is why I am happy to offer a\u00a0bit of help here: these equations can be found in the two following\u00a0papers: <a href=\"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/files\/2014\/12\/ICC-1994.pdf\">ICC 1994<\/a> and <a href=\"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/files\/2014\/12\/Eusipco-2000.pdf\">Eusipco 2000<\/a>.<\/p>\n<p>You will notice that, remarkably, the demapper can be implemented using a set of very simple equations.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I jointly teach the module entitled &#8220;Advanced Modulation and Coding&#8221; with Dr Martin Johnston. This module is offered to both our MSc and MEng students. Dr Johnston is in charge of the &#8220;coding&#8221; part, whereas I\u00a0teach the &#8220;modulation&#8221; part. You &hellip; <a href=\"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/2014\/12\/18\/an-old-paper\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":5796,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-34","post","type-post","status-publish","format-standard","hentry","category-eee8003-8104"],"_links":{"self":[{"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/posts\/34","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/users\/5796"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/comments?post=34"}],"version-history":[{"count":9,"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/posts\/34\/revisions"}],"predecessor-version":[{"id":59,"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/posts\/34\/revisions\/59"}],"wp:attachment":[{"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/media?parent=34"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/categories?post=34"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ncl.ac.uk\/stephanelegoff\/wp-json\/wp\/v2\/tags?post=34"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}