Content deleted Content added
Undid revision 1110351570 by 2001:1C06:2E88:4F00:8973:7E90:53F6:F830 (talk) zeros/zeroes is difficult, but apostrophe is definitely wrong |
m Adding archives WP:LINKROT |
||
Line 87:
== Disparity ==
Most long-distance communication channels cannot reliably transport a [[DC component]]. The DC component is also called the ''disparity'', the ''bias'', or the [[DC coefficient]]. The disparity of a bit pattern is the difference in the number of one bits vs the number of zero bits. The ''running disparity'' is the [[running total]] of the disparity of all previously transmitted bits.<ref>{{cite document |author=Jens Kröger |url=https://www.psi.ch/mu3e/ThesesEN/BachelorKroeger.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.psi.ch/mu3e/ThesesEN/BachelorKroeger.pdf |archive-date=2022-10-09 |url-status=live |title=Data Transmission at High Rates via Kapton Flexprints for the Mu3e Experiment |date=2014 |page=16}}</ref> The simplest possible line code, [[Unipolar encoding|unipolar]], gives too many errors on such systems, because it has an unbounded DC component.
Most line codes eliminate the DC component{{snd}} such codes are called [[DC-balanced]], zero-DC, or DC-free. There are three ways of eliminating the DC component:
Line 101:
{{cite patent |inventor=Peter E. K. Chow. |url=https://www.google.com.ar/patents/US4387366 |country=US |number=4387366 |title=Code converter for polarity-insensitive transmission systems |pubdate=1983}}
</ref><ref>
{{citation |author=David A. Glanzer |publisher=[[Fieldbus Foundation]] |url=http://www.fieldbus.org/images/stories/enduserresources/technicalreferences/documents/wiringinstallationguide.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.fieldbus.org/images/stories/enduserresources/technicalreferences/documents/wiringinstallationguide.pdf |archive-date=2022-10-09 |url-status=live |title=Fieldbus Application Guide ... Wiring and Installation |section=4.7 Polarity |page=10}}
</ref><ref>
{{cite book |author1=George C. Clark Jr. |author2=J. Bibb Cain |url=https://books.google.com/books?id=wgzyBwAAQBAJ |title=Error-Correction Coding for Digital Communications |date=2013 |page=255 |isbn=9781489921741 |publisher=Springer Science & Business Media |quote=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 ''transparent'' code. ...}}
| |||