Difference between revisions of "QAM"

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{{Mergefrom|Quadrature Amplitude Modulation}}
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'''Quadrature amplitude modulation''' ('''QAM''') is a method of modulating (encoding) digital signals on a cable television system.  It is commonly used to transmit digital cable TV channels on the otherwise analog RF cables, and can be decoded by several types of tuner cards (assuming that the video signal is not encrypted).
  
'''Quadrature amplitude modulation''' ('''QAM''') is a modulation scheme which conveys data by changing (modulating) the amplitude of two carrier waves. These two waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers — hence the name of the scheme. [http://en.wikipedia.org/wiki/QAM]
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QAM conveys data by changing (modulating) the amplitude of two carrier waves. These two waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers.
  
Oftentimes, the author is writing in the context of [[HDTV]] transmission. The other forms being [[OTA]] and satellite service.
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QAM is most often used in the context of [[HDTV]] transmission, but there are other forms: [[OTA]] and satellite service.
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More information about QAM is available at [[wikipedia:Quadrature amplitude modulation|Wikipedia]].
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== Related Links ==
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* [[Adding QAM Channels For HDTV Tuner Cards]]
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* [[Working QAM cable layout]]s
  
 
[[Category:Glossary]]
 
[[Category:Glossary]]
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[[Category:Modulation]]

Latest revision as of 04:07, 26 January 2011

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Quadrature amplitude modulation (QAM) is a method of modulating (encoding) digital signals on a cable television system. It is commonly used to transmit digital cable TV channels on the otherwise analog RF cables, and can be decoded by several types of tuner cards (assuming that the video signal is not encrypted).

QAM conveys data by changing (modulating) the amplitude of two carrier waves. These two waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers.

QAM is most often used in the context of HDTV transmission, but there are other forms: OTA and satellite service.

More information about QAM is available at Wikipedia.

Related Links