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class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Disparity</span> </div> </a> <ul id="toc-Disparity-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Polarity" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Polarity"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Polarity</span> </div> </a> <ul id="toc-Polarity-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Run-length_limited_codes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Run-length_limited_codes"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Run-length limited codes</span> </div> </a> <ul id="toc-Run-length_limited_codes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Synchronization" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Synchronization"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Synchronization</span> </div> </a> <ul id="toc-Synchronization-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Other_considerations" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Other_considerations"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Other considerations</span> </div> </a> <ul id="toc-Other_considerations-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Common_line_codes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Common_line_codes"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Common line codes</span> </div> </a> <button aria-controls="toc-Common_line_codes-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Common line codes subsection</span> </button> <ul id="toc-Common_line_codes-sublist" class="vector-toc-list"> <li id="toc-Optical_line_codes" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Optical_line_codes"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.1</span> <span>Optical line codes</span> </div> </a> <ul id="toc-Optical_line_codes-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" 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href="https://ca.wikipedia.org/wiki/Codi_de_l%C3%ADnia" title="Codi de línia – Catalan" lang="ca" hreflang="ca" data-title="Codi de línia" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Linkov%C3%BD_k%C3%B3d" title="Linkový kód – Czech" lang="cs" hreflang="cs" data-title="Linkový kód" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Leitungscode" title="Leitungscode – German" lang="de" hreflang="de" data-title="Leitungscode" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/C%C3%B3digos_en_l%C3%ADnea" title="Códigos en línea – Spanish" lang="es" hreflang="es" data-title="Códigos en línea" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Linea_kode" title="Linea kode – Basque" lang="eu" hreflang="eu" data-title="Linea kode" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%DA%A9%D8%AF%DB%8C%D9%86%DA%AF_%D8%AE%D8%B7" title="کدینگ خط – Persian" lang="fa" hreflang="fa" data-title="کدینگ خط" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Codage_en_ligne" title="Codage en ligne – French" lang="fr" hreflang="fr" data-title="Codage en ligne" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Codifica_di_linea" title="Codifica di linea – Italian" lang="it" hreflang="it" data-title="Codifica di linea" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Lijncodering" title="Lijncodering – Dutch" lang="nl" hreflang="nl" data-title="Lijncodering" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E4%BC%9D%E9%80%81%E8%B7%AF%E7%AC%A6%E5%8F%B7" title="伝送路符号 – Japanese" lang="ja" hreflang="ja" data-title="伝送路符号" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Kodowanie_liniowe" title="Kodowanie liniowe – Polish" lang="pl" hreflang="pl" data-title="Kodowanie liniowe" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%A4%D0%B8%D0%B7%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5_%D0%BA%D0%BE%D0%B4%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5" title="Физическое кодирование – Russian" lang="ru" hreflang="ru" data-title="Физическое кодирование" data-language-autonym="Русский" data-language-local-name="Russian" 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(min-width:720px){.mw-parser-output .stack-clear-left{float:left;clear:left}.mw-parser-output .stack-clear-right{float:right;clear:right}.mw-parser-output .stack-left{float:left}.mw-parser-output .stack-right{float:right}.mw-parser-output .stack-margin-clear-left{float:left;clear:left;margin-right:1em}.mw-parser-output .stack-margin-clear-right{float:right;clear:right;margin-left:1em}.mw-parser-output .stack-margin-left{float:left;margin-right:1em}.mw-parser-output .stack-margin-right{float:right;margin-left:1em}}</style><div class="stack mw-stack stack-right"><div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:NRZcode.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/55/NRZcode.png/220px-NRZcode.png" decoding="async" width="220" height="110" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/5/55/NRZcode.png 1.5x" data-file-width="256" data-file-height="128" /></a><figcaption>An example of coding a binary signal using rectangular <a href="/wiki/Pulse-amplitude_modulation" title="Pulse-amplitude modulation">pulse-amplitude modulation</a> with polar <a href="/wiki/Non-return-to-zero" title="Non-return-to-zero">non-return-to-zero</a> code</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Ami_encoding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Ami_encoding.svg/220px-Ami_encoding.svg.png" decoding="async" width="220" height="86" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Ami_encoding.svg/330px-Ami_encoding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Ami_encoding.svg/440px-Ami_encoding.svg.png 2x" data-file-width="1456" data-file-height="570" /></a><figcaption>An example of <a href="/wiki/Bipolar_encoding" title="Bipolar encoding">bipolar encoding</a>, or AMI.</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Manchester_code.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/98/Manchester_code.svg/220px-Manchester_code.svg.png" decoding="async" width="220" height="112" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/98/Manchester_code.svg/330px-Manchester_code.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/98/Manchester_code.svg/440px-Manchester_code.svg.png 2x" data-file-width="255" data-file-height="130" /></a><figcaption>Encoding of 11011000100 in <a href="/wiki/Manchester_encoding" class="mw-redirect" title="Manchester encoding">Manchester encoding</a> </figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Differential_manchester_encoding_Workaround.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/04/Differential_manchester_encoding_Workaround.svg/220px-Differential_manchester_encoding_Workaround.svg.png" decoding="async" width="220" height="60" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/04/Differential_manchester_encoding_Workaround.svg/330px-Differential_manchester_encoding_Workaround.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/04/Differential_manchester_encoding_Workaround.svg/440px-Differential_manchester_encoding_Workaround.svg.png 2x" data-file-width="512" data-file-height="139" /></a><figcaption>An example of <a href="/wiki/Differential_Manchester_encoding" title="Differential Manchester encoding">differential Manchester encoding</a></figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Biphase_Mark_Code.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Biphase_Mark_Code.svg/220px-Biphase_Mark_Code.svg.png" decoding="async" width="220" height="89" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Biphase_Mark_Code.svg/330px-Biphase_Mark_Code.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Biphase_Mark_Code.svg/440px-Biphase_Mark_Code.svg.png 2x" data-file-width="518" data-file-height="209" /></a><figcaption>An example of <a href="/wiki/Biphase_mark_code" class="mw-redirect" title="Biphase mark code">biphase mark code</a> </figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:MLT3encoding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/MLT3encoding.svg/220px-MLT3encoding.svg.png" decoding="async" width="220" height="86" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/MLT3encoding.svg/330px-MLT3encoding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b4/MLT3encoding.svg/440px-MLT3encoding.svg.png 2x" data-file-width="1456" data-file-height="570" /></a><figcaption>An example of <a href="/wiki/MLT-3_encoding" title="MLT-3 encoding">MLT-3 encoding</a></figcaption></figure> </div></div> <style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol 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.sidebar-title-with-pretitle a{color:var(--color-progressive)!important}}@media print{body.ns-0 .mw-parser-output .sidebar{display:none!important}}</style><table class="sidebar nomobile nowraplinks"><tbody><tr><th class="sidebar-title" style="background-color: #bdb"><a href="/wiki/Passband" title="Passband">Passband</a> <a href="/wiki/Modulation" title="Modulation">modulation</a></th></tr><tr><td class="sidebar-image"><span typeof="mw:File"><a href="/wiki/File:Modulation_categorization.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Modulation_categorization.svg/300px-Modulation_categorization.svg.png" decoding="async" width="300" height="72" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Modulation_categorization.svg/450px-Modulation_categorization.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Modulation_categorization.svg/600px-Modulation_categorization.svg.png 2x" data-file-width="1565" data-file-height="374" /></a></span></td></tr><tr><th class="sidebar-heading" style="background-color: #cfc"> <a href="/wiki/Modulation#Analog_modulation_methods" title="Modulation">Analog modulation</a></th></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Amplitude_modulation" title="Amplitude modulation">AM</a></li> <li><a href="/wiki/Frequency_modulation" title="Frequency modulation">FM</a></li> <li><a href="/wiki/Phase_modulation" title="Phase modulation">PM</a></li> <li><a href="/wiki/Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">QAM</a></li> <li><a href="/wiki/Space_modulation" title="Space modulation">SM</a></li> <li><a href="/wiki/Single-sideband_modulation" title="Single-sideband modulation">SSB</a></li></ul></td> </tr><tr><th class="sidebar-heading" style="background-color: #cfc"> <a href="/wiki/Modulation#Digital_modulation_methods" title="Modulation">Digital modulation</a></th></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Amplitude-shift_keying" title="Amplitude-shift keying">ASK</a></li> <li><a href="/wiki/Amplitude_and_phase-shift_keying" title="Amplitude and phase-shift keying">APSK</a></li> <li><a href="/wiki/Continuous_phase_modulation" title="Continuous phase modulation">CPM</a></li> <li><a href="/wiki/Frequency-shift_keying" title="Frequency-shift keying">FSK</a></li> <li><a href="/wiki/Multiple_frequency-shift_keying" title="Multiple frequency-shift keying">MFSK</a></li> <li><a href="/wiki/Minimum-shift_keying" title="Minimum-shift keying">MSK</a></li> <li><a href="/wiki/On%E2%80%93off_keying" title="On–off keying">OOK</a></li> <li><a href="/wiki/Pulse-position_modulation" title="Pulse-position modulation">PPM</a></li> <li><a href="/wiki/Phase-shift_keying" title="Phase-shift keying">PSK</a></li> <li><a href="/wiki/Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">QAM</a></li> <li><a href="/wiki/Single-carrier_FDMA" title="Single-carrier FDMA">SC-FDE</a></li> <li><a href="/wiki/Trellis_coded_modulation" title="Trellis coded modulation">TCM</a></li> <li><a href="/wiki/TC-PAM" title="TC-PAM">TC-PAM</a></li> <li><a href="/wiki/Wavelet_modulation" title="Wavelet modulation">WDM</a></li></ul></td> </tr><tr><th class="sidebar-heading" style="background-color: #cfc"> <a href="/wiki/Hierarchical_modulation" title="Hierarchical modulation">Hierarchical modulation</a></th></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">QAM</a></li> <li><a href="/wiki/Wavelet_modulation" title="Wavelet modulation">WDM</a></li></ul></td> </tr><tr><th class="sidebar-heading" style="background-color: #cfc"> <a href="/wiki/Spread_spectrum" title="Spread spectrum">Spread spectrum</a></th></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Chirp_spread_spectrum" title="Chirp spread spectrum">CSS</a></li> <li><a href="/wiki/Direct-sequence_spread_spectrum" title="Direct-sequence spread spectrum">DSSS</a></li> <li><a href="/wiki/Frequency-hopping_spread_spectrum" title="Frequency-hopping spread spectrum">FHSS</a></li> <li><a href="/wiki/Time-hopping" title="Time-hopping">THSS</a></li></ul></td> </tr><tr><th class="sidebar-heading" style="background-color: #cfc"> See also</th></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Category:Capacity-approaching_codes" title="Category:Capacity-approaching codes">Capacity-approaching codes</a></li> <li><a href="/wiki/Demodulation" title="Demodulation">Demodulation</a></li> <li><a class="mw-selflink selflink">Line coding</a></li> <li><a href="/wiki/Modem" title="Modem">Modem</a></li> <li><a href="/wiki/Angle_modulation" title="Angle modulation">AnM</a></li> <li><a href="/wiki/Polar_modulation" title="Polar modulation">PoM</a></li> <li><a href="/wiki/Pulse-amplitude_modulation" title="Pulse-amplitude modulation">PAM</a></li> <li><a href="/wiki/Pulse-code_modulation" title="Pulse-code modulation">PCM</a></li> <li><a href="/wiki/Pulse-density_modulation" title="Pulse-density modulation">PDM</a></li> <li><a href="/wiki/Pulse-width_modulation" title="Pulse-width modulation">PWM</a></li> <li><a href="/wiki/Delta-sigma_modulation" title="Delta-sigma modulation">ΔΣM</a></li> <li><a href="/wiki/Orthogonal_frequency-division_multiplexing" title="Orthogonal frequency-division multiplexing">OFDM</a></li> <li><a href="/wiki/Frequency-division_multiplexing" title="Frequency-division multiplexing">FDM</a></li> <li><a href="/wiki/Multiplexing" title="Multiplexing">Multiplexing</a></li></ul></td> </tr><tr><td class="sidebar-navbar"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Modulation_techniques" title="Template:Modulation techniques"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Modulation_techniques" title="Template talk:Modulation techniques"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Modulation_techniques" title="Special:EditPage/Template:Modulation techniques"><abbr title="Edit this template">e</abbr></a></li></ul></div></td></tr></tbody></table> <p>In <a href="/wiki/Telecommunications" title="Telecommunications">telecommunications</a>, a <b>line code</b> is a pattern of voltage, current, or photons used to represent digital data <a href="/wiki/Transmission_(telecommunications)" class="mw-redirect" title="Transmission (telecommunications)">transmitted</a> down a <a href="/wiki/Communication_channel" title="Communication channel">communication channel</a> or written to a <a href="/wiki/Storage_medium" class="mw-redirect" title="Storage medium">storage medium</a>. This repertoire of signals is usually called a <b>constrained code</b> in data storage systems.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Some signals are more prone to error than others as the physics of the communication channel or storage medium constrains the repertoire of signals that can be used reliably.<sup id="cite_ref-optics_2-0" class="reference"><a href="#cite_note-optics-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>Common line encodings are <a href="/wiki/Unipolar_encoding" title="Unipolar encoding">unipolar</a>, <a href="/wiki/Polar_encoding" class="mw-redirect" title="Polar encoding">polar</a>, <a href="/wiki/Bipolar_encoding" title="Bipolar encoding">bipolar</a>, and <a href="/wiki/Manchester_code" title="Manchester code">Manchester code</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Transmission_and_storage">Transmission and storage</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=1" title="Edit section: Transmission and storage"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>After line coding, the signal is put through a physical communication channel, either a <a href="/wiki/Transmission_medium" title="Transmission medium">transmission medium</a> or <a href="/wiki/Data_storage_medium" class="mw-redirect" title="Data storage medium">data storage medium</a>.<sup id="cite_ref-paulsen_3-0" class="reference"><a href="#cite_note-paulsen-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> The most common physical channels are: </p> <ul><li>the line-coded signal can directly be put on a <a href="/wiki/Transmission_line" title="Transmission line">transmission line</a>, in the form of variations of the voltage or current (often using <a href="/wiki/Differential_signaling" class="mw-redirect" title="Differential signaling">differential signaling</a>).</li> <li>the line-coded signal (the <i><a href="/wiki/Baseband" title="Baseband">baseband</a> signal</i>) undergoes further <a href="/wiki/Pulse_shaping" title="Pulse shaping">pulse shaping</a> (to reduce its frequency bandwidth) and then is <a href="/wiki/Modulation" title="Modulation">modulated</a> (to shift its frequency) to create an <i><a href="/wiki/RF_signal" class="mw-redirect" title="RF signal">RF signal</a></i> that can be sent through free space.</li> <li>the line-coded signal can be used to turn on and off a light source in <a href="/wiki/Free-space_optical_communication" title="Free-space optical communication">free-space optical communication</a>, most commonly used in an infrared <a href="/wiki/Remote_control" title="Remote control">remote control</a>.</li> <li>the line-coded signal can be printed on paper to create a <a href="/wiki/Bar_code" class="mw-redirect" title="Bar code">bar code</a>.</li> <li>the line-coded signal can be converted to magnetized spots on a <a href="/wiki/Hard_drive" class="mw-redirect" title="Hard drive">hard drive</a> or <a href="/wiki/Tape_drive" title="Tape drive">tape drive</a>.</li> <li>the line-coded signal can be converted to pits on an <a href="/wiki/Optical_disc" title="Optical disc">optical disc</a>.</li></ul> <p>Some of the more common binary line codes include: </p> <table class="wikitable"> <tbody><tr> <th>Signal</th> <th>Comments</th> <th>1 state</th> <th>0 state </th></tr> <tr> <td>NRZ–L</td> <td><a href="/wiki/Non-return-to-zero" title="Non-return-to-zero">Non-return-to-zero</a> level. This is the standard positive logic signal format used in digital circuits. </td> <td>forces a high level </td> <td>forces a low level </td></tr> <tr> <td>NRZ–M</td> <td>Non-return-to-zero mark </td> <td>forces a transition </td> <td>does nothing (keeps sending the previous level) </td></tr> <tr> <td>NRZ–S</td> <td>Non-return-to-zero space </td> <td>does nothing (keeps sending the previous level) </td> <td>forces a transition </td></tr> <tr> <td>RZ</td> <td>Return to zero </td> <td>goes high for half the bit period and returns to low </td> <td>stays low for the entire period </td></tr> <tr> <td>Biphase–L</td> <td>Manchester. Two consecutive bits of the same type force a transition at the beginning of a bit period. </td> <td>forces a negative transition in the middle of the bit </td> <td>forces a positive transition in the middle of the bit </td></tr> <tr> <td>Biphase–M</td> <td>Variant of Differential Manchester. There is always a transition halfway between the conditioned transitions. </td> <td>forces a transition </td> <td>keeps level constant </td></tr> <tr> <td>Biphase–S</td> <td>Differential Manchester used in Token Ring. There is always a transition halfway between the conditioned transitions. </td> <td>keeps level constant </td> <td>forces a transition </td></tr> <tr> <td>Differential Manchester (Alternative)</td> <td>Need a Clock, always a transition in the middle of the clock period </td> <td>is represented by no transition. </td> <td>is represented by a transition at the beginning of the clock period. </td></tr> <tr> <td>Bipolar</td> <td>The positive and negative pulses alternate. </td> <td>forces a positive or negative pulse for half the bit period </td> <td>keeps a zero level during bit period </td></tr></tbody></table> <figure class="mw-halign-center" typeof="mw:File/Frame"><a href="/wiki/File:Digital_signal_encoding_formats-en.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/95/Digital_signal_encoding_formats-en.svg/586px-Digital_signal_encoding_formats-en.svg.png" decoding="async" width="586" height="504" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/95/Digital_signal_encoding_formats-en.svg/879px-Digital_signal_encoding_formats-en.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/95/Digital_signal_encoding_formats-en.svg/1172px-Digital_signal_encoding_formats-en.svg.png 2x" data-file-width="586" data-file-height="504" /></a><figcaption>An arbitrary bit pattern in various binary line code formats</figcaption></figure> <p>Each line code has advantages and disadvantages. Line codes are chosen to meet one or more of the following criteria: </p> <ul><li>Minimize transmission hardware</li> <li>Facilitate synchronization</li> <li>Ease error detection and correction</li> <li>Achieve a target <a href="/wiki/Spectral_density" title="Spectral density">spectral density</a></li> <li>Eliminate a <a href="/wiki/DC_component" class="mw-redirect" title="DC component">DC component</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Disparity">Disparity</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=2" title="Edit section: Disparity"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Most long-distance communication channels cannot reliably transport a <a href="/wiki/DC_component" class="mw-redirect" title="DC component">DC component</a>. The DC component is also called the <i>disparity</i>, the <i>bias</i>, or the <a href="/wiki/DC_coefficient" class="mw-redirect" title="DC coefficient">DC coefficient</a>. The disparity of a bit pattern is the difference in the number of one bits vs the number of zero bits. The <i>running disparity</i> is the <a href="/wiki/Running_total" title="Running total">running total</a> of the disparity of all previously transmitted bits.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> The simplest possible line code, <a href="/wiki/Unipolar_encoding" title="Unipolar encoding">unipolar</a>, gives too many errors on such systems, because it has an unbounded DC component. </p><p>Most line codes eliminate the DC component –  such codes are called <a href="/wiki/DC-balanced" class="mw-redirect" title="DC-balanced">DC-balanced</a>, zero-DC, or DC-free. There are three ways of eliminating the DC component: </p> <ul><li>Use a <a href="/wiki/Constant-weight_code" title="Constant-weight code">constant-weight code</a>. Each transmitted <a href="/wiki/Code_word_(communication)" title="Code word (communication)">code word</a> in a constant-weight code is designed such that every code word that contains some positive or negative levels also contains enough of the opposite levels, such that the average level over each code word is zero. Examples of constant-weight codes include <a href="/wiki/Manchester_code" title="Manchester code">Manchester code</a> and <a href="/wiki/Interleaved_2_of_5" title="Interleaved 2 of 5">Interleaved 2 of 5</a>.</li> <li>Use a <a href="/wiki/Paired_disparity_code" title="Paired disparity code">paired disparity code</a>. Each code word in a paired disparity code that averages to a negative level is paired with another code word that averages to a positive level. The transmitter keeps track of the running DC buildup, and picks the code word that pushes the DC level back towards zero. The receiver is designed so that either code word of the pair decodes to the same data bits. Examples of paired disparity codes include <a href="/wiki/Alternate_mark_inversion" class="mw-redirect" title="Alternate mark inversion">alternate mark inversion</a>, <a href="/wiki/8b/10b" class="mw-redirect" title="8b/10b">8b/10b</a> and <a href="/wiki/4B3T" title="4B3T">4B3T</a>.</li> <li>Use a <a href="/wiki/Scrambler" title="Scrambler">scrambler</a>. For example, the scrambler specified in <style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><a href="/wiki/RFC_(identifier)" class="mw-redirect" title="RFC (identifier)">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc2615">2615</a> for <a href="/wiki/64b/66b_encoding" title="64b/66b encoding">64b/66b encoding</a>.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Polarity">Polarity</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=3" title="Edit section: Polarity"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Bipolar line codes have two polarities, are generally implemented as RZ, and have a radix of three since there are three distinct output levels (negative, positive and zero). One of the principle advantages of this type of code is that it can eliminate any DC component. This is important if the signal must pass through a transformer or a long transmission line. </p><p>Unfortunately, several long-distance communication channels have polarity ambiguity. Polarity-insensitive line codes compensate in these channels.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> There are three ways of providing unambiguous reception of 0 and 1 bits over such channels: </p> <ul><li>Pair each code word with the polarity-inverse of that code word. The receiver is designed so that either code word of the pair decodes to the same data bits. Examples include <a href="/wiki/Alternate_mark_inversion" class="mw-redirect" title="Alternate mark inversion">alternate mark inversion</a>, <a href="/wiki/Differential_Manchester_encoding" title="Differential Manchester encoding">Differential Manchester encoding</a>, <a href="/wiki/Coded_mark_inversion" title="Coded mark inversion">coded mark inversion</a> and <a href="/wiki/Miller_encoding" class="mw-redirect" title="Miller encoding">Miller encoding</a>.</li> <li><a href="/wiki/Differential_coding" title="Differential coding">differential coding</a> each symbol relative to the previous symbol. Examples include <a href="/wiki/MLT-3_encoding" title="MLT-3 encoding">MLT-3 encoding</a> and <a href="/wiki/NRZI" class="mw-redirect" title="NRZI">NRZI</a>.</li> <li>Invert the whole stream when inverted <a href="/wiki/Syncword" title="Syncword">syncwords</a> are detected, perhaps using <a href="/wiki/Differential_signalling#Polarity_switching" title="Differential signalling"> polarity switching </a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Run-length_limited_codes">Run-length limited codes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=4" title="Edit section: Run-length limited codes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>For reliable <a href="/wiki/Clock_recovery" title="Clock recovery">clock recovery</a> at the receiver, a <a href="/wiki/Run-length_limited" title="Run-length limited">run-length limitation</a> may be imposed on the generated channel sequence, i.e., the maximum number of consecutive ones or zeros is bounded to a reasonable number. A clock period is recovered by observing transitions in the received sequence, so that a maximum run length guarantees sufficient transitions to assure clock recovery quality. </p><p>RLL codes are defined by four main parameters: <i>m</i>, <i>n</i>, <i>d</i>, <i>k</i>. The first two, <i>m</i>/<i>n</i>, refer to the rate of the code, while the remaining two specify the minimal <i>d</i> and maximal <i>k</i> number of zeroes between consecutive ones. This is used in both <a href="/wiki/Telecommunications" title="Telecommunications">telecommunications</a> and storage systems that move a medium past a fixed <a href="/wiki/Recording_head" title="Recording head">recording head</a>.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p><p>Specifically, RLL bounds the length of stretches (runs) of repeated bits during which the signal does not change. If the runs are too long, clock recovery is difficult; if they are too short, the high frequencies might be attenuated by the communications channel. By <a href="/wiki/Modulation" title="Modulation">modulating</a> the <a href="/wiki/Data" title="Data">data</a>, RLL reduces the timing uncertainty in decoding the stored data, which would lead to the possible erroneous insertion or removal of bits when reading the data back. This mechanism ensures that the boundaries between bits can always be accurately found (preventing <a href="/wiki/Bit_slip" title="Bit slip">bit slip</a>), while efficiently using the media to reliably store the maximal amount of data in a given space. </p><p>Early disk drives used very simple encoding schemes, such as RLL (0,1) FM code, followed by RLL (1,3) MFM code which were widely used in <a href="/wiki/Hard_disk_drive" title="Hard disk drive">hard disk drives</a> until the mid-1980s and are still used in digital optical discs such as <a href="/wiki/CD" class="mw-redirect" title="CD">CD</a>, <a href="/wiki/DVD" title="DVD">DVD</a>, <a href="/wiki/Minidisc" class="mw-redirect" title="Minidisc">MD</a>, <a href="/wiki/Hi-MD" title="Hi-MD">Hi-MD</a> and <a href="/wiki/Blu-ray" title="Blu-ray">Blu-ray</a> using <a href="/wiki/Eight-to-Fourteen_Modulation" class="mw-redirect" title="Eight-to-Fourteen Modulation">EFM</a> and <a href="/w/index.php?title=EFMPLus&action=edit&redlink=1" class="new" title="EFMPLus (page does not exist)">EFMPLus</a> codes.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> Higher density RLL (2,7) and RLL (1,7) codes became the <a href="/wiki/De_facto_standard" title="De facto standard">de facto standards</a> for hard disks by the early 1990s.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (August 2019)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="Synchronization">Synchronization</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=5" title="Edit section: Synchronization"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Clock_recovery" title="Clock recovery">Clock recovery</a></div> <p>Line coding should make it possible for the receiver to synchronize itself to the <a href="/wiki/Phase_(waves)" title="Phase (waves)">phase</a> of the received signal. If the clock recovery is not ideal, then the signal to be decoded will not be sampled at the optimal times. This will increase the probability of error in the received data. </p><p>Biphase line codes require at least one transition per bit time. This makes it easier to synchronize the transceivers and detect errors, however, the baud rate is greater than that of NRZ codes. </p> <div class="mw-heading mw-heading2"><h2 id="Other_considerations">Other considerations</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=6" title="Edit section: Other considerations"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A line code will typically reflect technical requirements of the transmission medium, such as <a href="/wiki/Optical_fiber" title="Optical fiber">optical fiber</a> or <a href="/wiki/Shielded_twisted_pair" class="mw-redirect" title="Shielded twisted pair">shielded twisted pair</a>. These requirements are unique for each medium, because each one has different behavior related to interference, distortion, capacitance and attenuation.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Common_line_codes">Common line codes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=7" title="Edit section: Common line codes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1184024115">.mw-parser-output .div-col{margin-top:0.3em;column-width:30em}.mw-parser-output .div-col-small{font-size:90%}.mw-parser-output .div-col-rules{column-rule:1px solid #aaa}.mw-parser-output .div-col dl,.mw-parser-output .div-col ol,.mw-parser-output .div-col ul{margin-top:0}.mw-parser-output .div-col li,.mw-parser-output .div-col dd{page-break-inside:avoid;break-inside:avoid-column}</style><div class="div-col" style="column-width: 30em;"> <ul><li><a href="/wiki/2B1Q" title="2B1Q">2B1Q</a></li> <li><a href="/wiki/4B3T" title="4B3T">4B3T</a></li> <li><a href="/wiki/4B5B" title="4B5B">4B5B</a></li> <li><a href="/wiki/6b/8b_encoding" title="6b/8b encoding">6b/8b encoding</a></li> <li><a href="/wiki/8b/10b_encoding" title="8b/10b encoding">8b/10b encoding</a></li> <li><a href="/wiki/64b/66b_encoding" title="64b/66b encoding">64b/66b encoding</a></li> <li><a href="/wiki/128b/130b_encoding" class="mw-redirect" title="128b/130b encoding">128b/130b encoding</a></li> <li><a href="/wiki/Alternate_mark_inversion" class="mw-redirect" title="Alternate mark inversion">Alternate mark inversion</a> (AMI)</li> <li><a href="/wiki/Coded_mark_inversion" title="Coded mark inversion">Coded mark inversion</a> (CMI)</li> <li><a href="/wiki/EFMPlus" class="mw-redirect" title="EFMPlus">EFMPlus</a>, used in <a href="/wiki/DVD" title="DVD">DVDs</a></li> <li><a href="/wiki/Eight-to-fourteen_modulation" title="Eight-to-fourteen modulation">Eight-to-fourteen modulation</a> (EFM), used in <a href="/wiki/Compact_disc" title="Compact disc">compact discs</a></li> <li><a href="/wiki/Hamming_code" title="Hamming code">Hamming code</a></li> <li><a href="/wiki/Hybrid_ternary_code" title="Hybrid ternary code">Hybrid ternary code</a></li> <li><a href="/wiki/Manchester_code" title="Manchester code">Manchester code</a> and <a href="/wiki/Differential_Manchester_encoding" title="Differential Manchester encoding">differential Manchester</a></li> <li><a href="/wiki/Mark_and_space" title="Mark and space">Mark and space</a></li> <li><a href="/wiki/MLT-3_encoding" title="MLT-3 encoding">MLT-3 encoding</a></li> <li><a href="/wiki/Modified_AMI_code" title="Modified AMI code">Modified AMI codes</a>: B8ZS, B6ZS, B3ZS, HDB3</li> <li><a href="/wiki/Modified_frequency_modulation" title="Modified frequency modulation">Modified frequency modulation</a>, Miller encoding and delay encoding</li> <li><a href="/wiki/Non-return-to-zero" title="Non-return-to-zero">Non-return-to-zero</a> (NRZ)</li> <li><a href="/wiki/Non-return-to-zero,_inverted" class="mw-redirect" title="Non-return-to-zero, inverted">Non-return-to-zero, inverted</a> (NRZI)</li> <li><a href="/wiki/Pulse-position_modulation" title="Pulse-position modulation">Pulse-position modulation</a> (PPM)</li> <li><a href="/wiki/Return-to-zero" title="Return-to-zero">Return-to-zero</a> (RZ)</li> <li><a href="/wiki/TC-PAM" title="TC-PAM">TC-PAM</a></li></ul> </div> <div class="mw-heading mw-heading3"><h3 id="Optical_line_codes">Optical line codes</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=8" title="Edit section: Optical line codes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Alternate-Phase_Return-to-Zero" title="Alternate-Phase Return-to-Zero">Alternate-Phase Return-to-Zero</a> (APRZ)</li> <li><a href="/wiki/Carrier-Suppressed_Return-to-Zero" title="Carrier-Suppressed Return-to-Zero">Carrier-Suppressed Return-to-Zero</a> (CSRZ)</li> <li><a href="/wiki/IEEE_1355#Slice:_TS-FO-02" title="IEEE 1355">Three of Six, Fiber Optical</a> (TS-FO)</li></ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=9" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Physical_layer" title="Physical layer">Physical layer</a></li> <li><a href="/wiki/Self-synchronizing_code" title="Self-synchronizing code">Self-synchronizing code</a> and bit synchronization</li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=10" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFK._Schouhamer_Immink2022" class="citation journal cs1"><a href="/wiki/Kees_Schouhamer_Immink" title="Kees Schouhamer Immink">K. Schouhamer Immink</a> (2022). <a rel="nofollow" class="external text" href="https://www.researchgate.net/publication/362866105">"Innovation in Constrained Codes"</a>. <i>IEEE Communications Magazine</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2022-10-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Communications+Magazine&rft.atitle=Innovation+in+Constrained+Codes&rft.date=2022&rft.au=K.+Schouhamer+Immink&rft_id=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F362866105&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-optics-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-optics_2-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFK._Schouhamer_Immink2001" class="citation journal cs1"><a href="/wiki/Kees_Schouhamer_Immink" title="Kees Schouhamer Immink">K. Schouhamer Immink</a> (2001). <a rel="nofollow" class="external text" href="https://www.researchgate.net/publication/3234561">"A Survey of Codes for Optical Disk Recording"</a>. <i>IEEE Journal on Selected Areas in Communications</i>. <b>19</b>: 751–764<span class="reference-accessdate">. Retrieved <span class="nowrap">2018-02-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Journal+on+Selected+Areas+in+Communications&rft.atitle=A+Survey+of+Codes+for+Optical+Disk+Recording&rft.volume=19&rft.pages=751-764&rft.date=2001&rft.au=K.+Schouhamer+Immink&rft_id=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F3234561&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-paulsen-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-paulsen_3-0">^</a></b></span> <span class="reference-text">Karl Paulsen. <a rel="nofollow" class="external text" href="http://www.tvtechnology.com/media-servers/0150/coding-for-magnetic-storage-mediums/186738">"Coding for Magnetic Storage Mediums"</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20140521215946/http://www.tvtechnology.com/media-servers/0150/coding-for-magnetic-storage-mediums/186738">Archived</a> 2014-05-21 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>.2007.</span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAbdullatif_GlassNidhal_Abdulazizand_Eesa_Bastaki2007" class="citation cs2">Abdullatif Glass; Nidhal Abdulaziz; and Eesa Bastaki (2007), <a rel="nofollow" class="external text" href="http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1285&context=dubaipapers">"Slope line coding for telecommunication networks"</a>, <i>IEEE International Conference on Signal Processing and Communication</i>, Dubai: IEEE: 1537, <q>Line codes ... facilitates the transmission of data over telecommunication and computer networks and its storage in multimedia systems.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+International+Conference+on+Signal+Processing+and+Communication&rft.atitle=Slope+line+coding+for+telecommunication+networks&rft.pages=1537&rft.date=2007&rft.au=Abdullatif+Glass&rft.au=Nidhal+Abdulaziz&rft.au=and+Eesa+Bastaki&rft_id=http%3A%2F%2Fro.uow.edu.au%2Fcgi%2Fviewcontent.cgi%3Farticle%3D1285%26context%3Ddubaipapers&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJens_Kröger2014" class="citation web cs1">Jens Kröger (2014). <a rel="nofollow" class="external text" href="https://www.psi.ch/mu3e/ThesesEN/BachelorKroeger.pdf">"Data Transmission at High Rates via Kapton Flexprints for the Mu3e Experiment"</a> <span class="cs1-format">(PDF)</span>. p. 16. <a rel="nofollow" class="external text" href="https://ghostarchive.org/archive/20221009/https://www.psi.ch/mu3e/ThesesEN/BachelorKroeger.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 2022-10-09.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Data+Transmission+at+High+Rates+via+Kapton+Flexprints+for+the+Mu3e+Experiment&rft.pages=16&rft.date=2014&rft.au=Jens+Kr%C3%B6ger&rft_id=https%3A%2F%2Fwww.psi.ch%2Fmu3e%2FThesesEN%2FBachelorKroeger.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"> <style data-mw-deduplicate="TemplateStyles:r1041539562">.mw-parser-output .citation{word-wrap:break-word}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}</style><span class="citation patent" id="CITEREFPeter_E._K._Chow.1983"><a rel="nofollow" class="external text" href="https://www.google.com.ar/patents/US4387366">US 4387366</a>, Peter E. K. Chow., "Code converter for polarity-insensitive transmission systems", published 1983</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Apatent&rft.number=4387366&rft.cc=US&rft.title=Code+converter+for+polarity-insensitive+transmission+systems&rft.inventor=Peter+E.+K.+Chow.&rft.pubdate=1983"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDavid_A._Glanzer" class="citation cs2">David A. Glanzer, "4.7 Polarity", <a rel="nofollow" class="external text" href="http://www.fieldbus.org/images/stories/enduserresources/technicalreferences/documents/wiringinstallationguide.pdf"><i>Fieldbus Application Guide ... Wiring and Installation</i></a> <span class="cs1-format">(PDF)</span>, <a href="/wiki/Fieldbus_Foundation" title="Fieldbus Foundation">Fieldbus Foundation</a>, p. 10, <a rel="nofollow" class="external text" href="https://ghostarchive.org/archive/20221009/http://www.fieldbus.org/images/stories/enduserresources/technicalreferences/documents/wiringinstallationguide.pdf">archived</a> <span class="cs1-format">(PDF)</span> from the original on 2022-10-09</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=4.7+Polarity&rft.btitle=Fieldbus+Application+Guide+...+Wiring+and+Installation&rft.pages=10&rft.pub=Fieldbus+Foundation&rft.au=David+A.+Glanzer&rft_id=http%3A%2F%2Fwww.fieldbus.org%2Fimages%2Fstories%2Fenduserresources%2Ftechnicalreferences%2Fdocuments%2Fwiringinstallationguide.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGeorge_C._Clark_Jr.J._Bibb_Cain2013" class="citation book cs1">George C. Clark Jr.; J. Bibb Cain (2013). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=wgzyBwAAQBAJ"><i>Error-Correction Coding for Digital Communications</i></a>. Springer Science & Business Media. p. 255. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781489921741" title="Special:BookSources/9781489921741"><bdi>9781489921741</bdi></a>. <q>When PSK data modulation is used, the potential exists for an ambiguity in the polarity of the received channel symbols. This problem can be solved in one of two ways. First ... a so-called <i>transparent</i> code. ...</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Error-Correction+Coding+for+Digital+Communications&rft.pages=255&rft.pub=Springer+Science+%26+Business+Media&rft.date=2013&rft.isbn=9781489921741&rft.au=George+C.+Clark+Jr.&rft.au=J.+Bibb+Cain&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DwgzyBwAAQBAJ&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPrakash_C._Gupta2013" class="citation book cs1">Prakash C. Gupta (2013). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=Zr1nAgAAQBAJ"><i>Data Communications and Computer Networks</i></a>. PHI Learning Pvt. Ltd. p. 13. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9788120348646" title="Special:BookSources/9788120348646"><bdi>9788120348646</bdi></a>. <q>Another benefit of differential encoding is its insensitivity to polarity of the signal. ... If the leads of a twisted pair are accidentally reversed...</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Data+Communications+and+Computer+Networks&rft.pages=13&rft.pub=PHI+Learning+Pvt.+Ltd.&rft.date=2013&rft.isbn=9788120348646&rft.au=Prakash+C.+Gupta&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DZr1nAgAAQBAJ&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKees_Schouhamer_Immink1990" class="citation journal cs1"><a href="/wiki/Kees_Schouhamer_Immink" title="Kees Schouhamer Immink">Kees Schouhamer Immink</a> (December 1990). <a rel="nofollow" class="external text" href="https://www.researchgate.net/publication/2984369">"Runlength-Limited Sequences"</a>. <i>Proceedings of the IEEE</i>. <b>78</b> (11): 1745–1759. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2F5.63306">10.1109/5.63306</a>. <q>A detailed description is furnished of the limiting properties of runlength limited sequences.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Proceedings+of+the+IEEE&rft.atitle=Runlength-Limited+Sequences&rft.volume=78&rft.issue=11&rft.pages=1745-1759&rft.date=1990-12&rft_id=info%3Adoi%2F10.1109%2F5.63306&rft.au=Kees+Schouhamer+Immink&rft_id=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F2984369&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKees_Schouhamer_Immink1995" class="citation journal cs1 cs1-prop-long-vol"><a href="/wiki/Kees_Schouhamer_Immink" title="Kees Schouhamer Immink">Kees Schouhamer Immink</a> (1995). <a rel="nofollow" class="external text" href="https://www.researchgate.net/publication/3179483">"EFMPlus: The Coding Format of the MultiMedia Compact Disc"</a>. <i>IEEE Transactions on Consumer Electronics</i>. CE-41: 491–497. <q>A high-density alternative to EFM is described.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=IEEE+Transactions+on+Consumer+Electronics&rft.atitle=EFMPlus%3A+The+Coding+Format+of+the+MultiMedia+Compact+Disc&rft.volume=CE-41&rft.pages=491-497&rft.date=1995&rft.au=Kees+Schouhamer+Immink&rft_id=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F3179483&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDong2007" class="citation book cs1">Dong, Jielin (2007). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=On_Hh23IXDUC&pg=PA284"><i>Network Dictionary</i></a>. Javvin Technologies Inc. p. 284. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781602670006" title="Special:BookSources/9781602670006"><bdi>9781602670006</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Network+Dictionary&rft.pages=284&rft.pub=Javvin+Technologies+Inc.&rft.date=2007&rft.isbn=9781602670006&rft.aulast=Dong&rft.aufirst=Jielin&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DOn_Hh23IXDUC%26pg%3DPA284&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span></span> </li> </ol></div></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1041539562"><span class="citation FS1037C MS188"><span class="noviewer" typeof="mw:File"><span><img alt="Public Domain" src="//upload.wikimedia.org/wikipedia/en/thumb/6/62/PD-icon.svg/12px-PD-icon.svg.png" decoding="async" width="12" height="12" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/6/62/PD-icon.svg/18px-PD-icon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/6/62/PD-icon.svg/24px-PD-icon.svg.png 2x" data-file-width="196" data-file-height="196" /></span></span> This article incorporates <a href="/wiki/Copyright_status_of_works_by_the_federal_government_of_the_United_States" title="Copyright status of works by the federal government of the United States">public domain material</a> from <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20220122224547/https://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm"><i>Federal Standard 1037C</i></a>. <a href="/wiki/General_Services_Administration" title="General Services Administration">General Services Administration</a>. Archived from <a rel="nofollow" class="external text" href="https://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm">the original</a> on 2022-01-22.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Federal+Standard+1037C&rft.pub=General+Services+Administration&rft_id=https%3A%2F%2Fwww.its.bldrdoc.gov%2Ffs-1037%2Ffs-1037c.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALine+code" class="Z3988"></span> (in support of <a href="/wiki/MIL-STD-188" title="MIL-STD-188">MIL-STD-188</a>).</span></li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Line_code&action=edit&section=11" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130418052107/http://www.electronics.dit.ie/staff/amoloney/lecture-9.pdf">Line Coding Lecture No. 9</a></li> <li><a rel="nofollow" class="external text" href="http://www.fiberoptics4sale.com/wordpress/line-coding-in-digital-communication/">Line Coding in Digital Communication</a></li> <li><a rel="nofollow" class="external text" href="https://www.ac.uma.es/~guille/codsim2.0/">CodSim 2.0: Open source simulator for Digital Data Communications Model at the University of Malaga written in HTML</a></li></ul> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output 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title="Line coding">Line coding</a> (digital baseband transmission)</div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Main articles</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Unipolar_encoding" title="Unipolar encoding">Unipolar encoding</a></li> <li><a href="/wiki/Bipolar_encoding" title="Bipolar encoding">Bipolar encoding</a></li> <li><a href="/wiki/On%E2%80%93off_keying" title="On–off keying">On–off keying</a></li> <li><a href="/wiki/Mark_and_space" title="Mark and space">Mark and space</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="4" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/File:Digital_signal_encoding_formats-en.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/95/Digital_signal_encoding_formats-en.svg/240px-Digital_signal_encoding_formats-en.svg.png" decoding="async" width="240" height="206" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/95/Digital_signal_encoding_formats-en.svg/360px-Digital_signal_encoding_formats-en.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/95/Digital_signal_encoding_formats-en.svg/480px-Digital_signal_encoding_formats-en.svg.png 2x" data-file-width="586" data-file-height="504" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Basic <a class="mw-selflink selflink">line codes</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Return-to-zero" title="Return-to-zero">Return to zero (RZ)</a></li> <li><a href="/wiki/Non-return-to-zero#Non-return-to-zero_level" title="Non-return-to-zero">Non-return-to-zero, level (NRZ/NRZ-L)</a></li> <li><a href="/wiki/Non-return-to-zero#Non-return-to-zero_inverted" title="Non-return-to-zero">Non-return-to-zero, inverted (NRZ-I)</a></li> <li><a href="/wiki/Non-return-to-zero#Non-return-to-zero_space" title="Non-return-to-zero">Non-return-to-zero, space (NRZ-S)</a></li> <li><a href="/wiki/Manchester_code" title="Manchester code">Manchester</a></li> <li><a href="/wiki/Differential_Manchester_encoding" title="Differential Manchester encoding">Differential Manchester/biphase (Bi-φ)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Extended line codes</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Conditioned_diphase" class="mw-redirect" title="Conditioned diphase">Conditioned diphase</a></li> <li><a href="/wiki/4B3T" title="4B3T">4B3T</a></li> <li><a href="/wiki/4B5B" title="4B5B">4B5B</a></li> <li><a href="/wiki/2B1Q" title="2B1Q">2B1Q</a></li> <li><a href="/wiki/Bipolar_encoding#Alternate_mark_inversion" title="Bipolar encoding">Alternate mark inversion</a></li> <li><a href="/wiki/Modified_AMI_code" title="Modified AMI code">Modified AMI code</a></li> <li><a href="/wiki/Coded_mark_inversion" title="Coded mark inversion">Coded mark inversion</a></li> <li><a href="/wiki/MLT-3_encoding" title="MLT-3 encoding">MLT-3 encoding</a></li> <li><a href="/wiki/Hybrid_ternary_code" title="Hybrid ternary code">Hybrid ternary code</a></li> <li><a href="/wiki/6b/8b_encoding" title="6b/8b encoding">6b/8b encoding</a></li> <li><a href="/wiki/8b/10b_encoding" title="8b/10b encoding">8b/10b encoding</a></li> <li><a href="/wiki/64b/66b_encoding" title="64b/66b encoding">64b/66b encoding</a></li> <li><a href="/wiki/Eight-to-fourteen_modulation" title="Eight-to-fourteen modulation">Eight-to-fourteen modulation</a></li> <li><a href="/wiki/Delay_encoding" class="mw-redirect" title="Delay encoding">Delay/Miller encoding</a></li> <li><a href="/wiki/TC-PAM" title="TC-PAM">TC-PAM</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Optical line codes</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Carrier-suppressed_return-to-zero" class="mw-redirect" title="Carrier-suppressed return-to-zero">Carrier-suppressed return-to-zero</a></li> <li><a href="/wiki/Alternate-phase_return-to-zero" class="mw-redirect" title="Alternate-phase return-to-zero">Alternate-phase return-to-zero</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="3"><div> <ul><li><i>See also:</i> <a href="/wiki/Baseband" title="Baseband">Baseband</a></li> <li><a href="/wiki/Baud" title="Baud">Baud</a></li> <li><a href="/wiki/Bit_rate" title="Bit rate">Bit rate</a></li> <li><a href="/wiki/Digital_signal" title="Digital signal">Digital signal</a></li> <li><a href="/wiki/Digital_transmission" class="mw-redirect" title="Digital transmission">Digital transmission</a></li> <li><a href="/wiki/Ethernet_physical_layer" title="Ethernet physical layer">Ethernet physical layer</a></li> <li><a href="/wiki/Modulation#Pulse_modulation_methods" title="Modulation">Pulse modulation methods</a></li> <li><a href="/wiki/Pulse-amplitude_modulation" title="Pulse-amplitude modulation">Pulse-amplitude modulation</a> (PAM)</li> <li><a href="/wiki/Pulse-code_modulation" title="Pulse-code modulation">Pulse-code modulation</a> (PCM)</li> <li><a href="/wiki/Serial_communication" title="Serial communication">Serial communication</a></li> <li><a href="/wiki/Category:Line_codes" title="Category:Line codes">Category:Line codes</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" 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