{"id":2856,"date":"2024-08-14T19:00:51","date_gmt":"2024-08-14T13:30:51","guid":{"rendered":"https:\/\/study.madeeasy.in\/?p=2856"},"modified":"2025-07-16T15:05:08","modified_gmt":"2025-07-16T09:35:08","slug":"multiplexing","status":"publish","type":"post","link":"https:\/\/www.madeeasy.in\/study\/ec\/communication-systems\/multiplexing","title":{"rendered":"Multiplexing"},"content":{"rendered":"<p style=\"text-align: justify;\"><strong>Multiplexing<\/strong> is the sending of a number of separate signals together over the same cable or bearer, simultaneously without interference. Multiplexing is of two types:<\/p>\n<ul style=\"text-align: justify;\">\n<li>Time Division Multiplexing<\/li>\n<li>Frequency Division Multiplexing<\/li>\n<\/ul>\n<h2 style=\"text-align: justify;\">Frequency Division Multiplexing<\/h2>\n<ul style=\"text-align: justify;\">\n<li>The operation of FDM is based on sharing the available bandwidth of a communication channel among the signals to be transmitted.<\/li>\n<li>In FDM, a number of signal share the channel bandwidth and each signal is modulated by a different carrier frequency. The modulator outputs will contain sidebands of corresponding signals. The modulator outputs are added together in a adder.<\/li>\n<li>In receiver sides, the composite signals is applied to group of bandpass filters (BPF). Each filter will pass only its channel and reject all other channels. The channel demodulator then removes carrier and recovers original signal back.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-2857 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/08\/division-multiplexing.jpg\" alt=\"Division Multiplexing\" width=\"545\" height=\"190\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/division-multiplexing.jpg 545w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/division-multiplexing-300x105.jpg 300w\" sizes=\"auto, (max-width: 545px) 100vw, 545px\" \/><\/p>\n<ul style=\"text-align: justify;\">\n<li>LPF is used to bandlimit the message signal.<\/li>\n<li>Suppose there are two message signals.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-2858 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/08\/message-signals.jpg\" alt=\"Message Signals\" width=\"373\" height=\"102\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/message-signals.jpg 373w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/message-signals-300x82.jpg 300w\" sizes=\"auto, (max-width: 373px) 100vw, 373px\" \/><\/p>\n<ul style=\"text-align: justify;\">\n<li>If no modulator is used and they are transmitted through channel, then interference occurs.<\/li>\n<li>If they are modulated by same frequency e.g. 15 kHz.<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-2859 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/08\/frequency.jpg\" alt=\"Frequency\" width=\"364\" height=\"101\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/frequency.jpg 364w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/frequency-300x83.jpg 300w\" sizes=\"auto, (max-width: 364px) 100vw, 364px\" \/><br \/>\nThen, also they occupy same frequency band and interference occurs.<\/p>\n<ul style=\"text-align: justify;\">\n<li>If they are modulated with different carrier frequencies f<sub>c1<\/sub> and f<sub>c2<\/sub><\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-2860 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/08\/carrier-frequencies.jpg\" alt=\"Carrier Frequencies\" width=\"341\" height=\"108\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/carrier-frequencies.jpg 341w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/08\/carrier-frequencies-300x95.jpg 300w\" sizes=\"auto, (max-width: 341px) 100vw, 341px\" \/><\/p>\n<p style=\"text-align: justify;\">Now, to avoid any interference<\/p>\n<p style=\"text-align: center;\">(<em>f<sub>c2<\/sub><\/em>\u00a0&#8211; 10 K) &#8211; (<em>f<sub>c1<\/sub><\/em>\u00a0+ 10 K) &gt;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0<\/p>\n<p style=\"text-align: center;\"><em>f<sub>c2<\/sub><\/em>\u00a0&#8211; <em>f<sub>c1<\/sub><\/em>\u00a0&gt;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 20 K<\/p>\n<h3 style=\"text-align: justify;\">Advantages of FDM<\/h3>\n<ul style=\"text-align: justify;\">\n<li>Large number of signals can be transmitted simultaneously.<\/li>\n<li>No synchronization is needed between transmitter and receiver.<\/li>\n<li>Demodulation is easy.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\">Disadvantages of FDM<\/h3>\n<ul style=\"text-align: justify;\">\n<li>Communication channel must have large bandwidth.<\/li>\n<li>Large number of modulators and filters are required.<\/li>\n<li>Crosstalk occurs between consecutive channels.<\/li>\n<li>Intermodulation distortion may occur.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\">Application of FDM<\/h3>\n<ul>\n<li style=\"text-align: justify;\">Telephone system.<\/li>\n<li style=\"text-align: justify;\">AM, FM, radio broadcasting.<\/li>\n<li style=\"text-align: justify;\">TV broadcasting<\/li>\n<li style=\"text-align: justify;\">First generation of cellular phones used FDM.<\/li>\n<\/ul>\n<p style=\"text-align: center;\"><a class=\"btn btn-danger\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/ec\/communication-systems\/pulse-modulation\/\" target=\"_blank\" rel=\"noopener\">&lt;&lt; Previous<\/a> | <a class=\"btn btn-success\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/ec\/communication-systems\/data-transmission-schemes\/\" target=\"_blank\" rel=\"noopener\"> Next &gt;&gt;<\/a><br \/>\n<strong> Must Read: <\/strong> <a href=\"https:\/\/study.madeeasy.in\/subjects\/what-is-communication\/\" target=\"_blank\" rel=\"noopener\"><strong>What is Communication?<\/strong><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Multiplexing is the sending of a number of separate signals together over the same cable or bearer, simultaneously without interference.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[758,6],"tags":[793,791,792],"class_list":["post-2856","post","type-post","status-publish","format-standard","hentry","category-communication-systems","category-ec","tag-advantages-of-fdm","tag-frequency-division-multiplexing","tag-message-signals"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/2856","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=2856"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/2856\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=2856"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=2856"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=2856"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}