Amplitude and phase-shift keying: Difference between revisions
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'''Amplitude and phase-shift keying''' or '''asymmetric phase-shift keying''' ('''APSK'''), is a [[Digital data|digital]] [[modulation]] scheme that conveys [[Data#Uses of data in computing|data]] by changing, or modulating, both the [[amplitude]] and the [[Phase (waves)|phase]] of a reference [[Signal (information theory)|signal]] (the [[carrier wave]]). In other words, it combines both [[Amplitude-shift keying]] (ASK) and [[Phase-shift keying]] (PSK) to increase the [[Symbol (data)|symbol-set]]. It can be considered as a superclass of [[Quadrature amplitude modulation]] (QAM). The advantage over conventional QAM, for example 16-QAM, is lower number of possible amplitude levels. |
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Moreover, a careful design of the constellation geometry enables to approach the Gaussian capacity when the constellation size grows to infinity. For the regular QAM constellations, a gap of 1.56 dB is observed. The previous solution, where the constellation has a Gaussian shape, is called constellation shaping. |
Moreover, a careful design of the constellation geometry enables to approach the Gaussian capacity when the constellation size grows to infinity. For the regular QAM constellations, a gap of 1.56 dB is observed. The previous solution, where the constellation has a Gaussian shape, is called constellation shaping. |
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==References== |
==References== |
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* [http://www.ebu.ch/en/technical/trev/trev_300-morello.pdf DVB-Flexible Serially Concatenated Convolutional Turbo Codes with Near-Shannon bound performance for telemetry applications |
* [http://www.ebu.ch/en/technical/trev/trev_300-morello.pdf DVB-Flexible Serially Concatenated Convolutional Turbo Codes with Near-Shannon bound performance for telemetry applications], [[CCSDS]]-131.2-O-1. |
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*H. Méric, [http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7105353&newsearch=true&queryText=%20Approaching%20the%20Gaussian%20channel%20capacity%20with%20APSK%20constellations Approaching The Gaussian Channel Capacity With APSK Constellations], ''IEEE Communications Letters''. |
*H. Méric, [http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7105353&newsearch=true&queryText=%20Approaching%20the%20Gaussian%20channel%20capacity%20with%20APSK%20constellations Approaching The Gaussian Channel Capacity With APSK Constellations], ''IEEE Communications Letters''. |
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Revision as of 19:00, 25 May 2016
This article needs additional citations for verification. (August 2008) |
Passband modulation |
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Analog modulation |
Digital modulation |
Hierarchical modulation |
Spread spectrum |
See also |
Amplitude and phase-shift keying or asymmetric phase-shift keying (APSK), is a digital modulation scheme that conveys data by changing, or modulating, both the amplitude and the phase of a reference signal (the carrier wave). In other words, it combines both Amplitude-shift keying (ASK) and Phase-shift keying (PSK) to increase the symbol-set. It can be considered as a superclass of Quadrature amplitude modulation (QAM). The advantage over conventional QAM, for example 16-QAM, is lower number of possible amplitude levels.
Moreover, a careful design of the constellation geometry enables to approach the Gaussian capacity when the constellation size grows to infinity. For the regular QAM constellations, a gap of 1.56 dB is observed. The previous solution, where the constellation has a Gaussian shape, is called constellation shaping.
References
- DVB-Flexible Serially Concatenated Convolutional Turbo Codes with Near-Shannon bound performance for telemetry applications, CCSDS-131.2-O-1.
- H. Méric, Approaching The Gaussian Channel Capacity With APSK Constellations, IEEE Communications Letters.