TC-PAM

<p>Trellis-coded pulse-amplitude modulation (TC-PAM) is the <a href="/facts/Modulation/aAXPjINv">modulation</a> format that is used in <a href="/facts/HDSL2/4xKX6pYN">HDSL2</a> and <a href="/facts/G.SHDSL/sACbGbHh">G.SHDSL</a>. It is a variant of <a href="/facts/Trellis_coded_modulation/QqfUccMq">trellis coded modulation</a> (TCM) which uses a one-dimensional <a href="/facts/Pulse-amplitude_modulation/Y30VmMJI">pulse-amplitude modulation</a> (PAM) symbol space, as opposed to a two-dimensional <a href="/facts/Quadrature_amplitude_modulation/02j52SWG">quadrature amplitude modulation</a> (QAM) symbol space. Compared to the <a href="/facts/2B1Q/rC9KAydW">2B1Q</a> scheme used in the older <a href="/facts/HDSL/x09Ct0HJ">HDSL</a> and <a href="/facts/Symmetric_digital_subscriber_line/7YwchjIc">SDSL</a> standards, TC-PAM improves range at a given bit-rate and provides enhanced spectral compatibility with <a href="/facts/ADSL/Y5wsglVy">ADSL</a>.
</p><p>TC-PAM is also known as 4B1H, because it uses 16 levels to represents a 4 digit binary, 4 <a href="/facts/Binary_code/v5YF0sQl">Binary</a> 1 <a href="/facts/Hexadecimal/02ohQW22">Hexadecimal</a>.
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TC-PAM open-in-new

TC-PAM