Back Modulació per desplaçament d'amplitud i fase Catalan Amplituden- und Phasenmodulation German Modulación por desplazamiento de amplitud y fase Spanish کلیدگذاری تغییر دامنه و فاز Persian Modulation d'amplitude et de phase French 진폭 위상 편이 방식 Korean

Amplitude and phase-shift keying

Passband modulation
Analog modulation
Digital modulation
Hierarchical modulation
Spread spectrum
See also

Amplitude and phase-shift keying (APSK) is a digital modulation scheme that conveys data by modulating both the amplitude and the phase of a carrier wave. In other words, it combines both amplitude-shift keying (ASK) and phase-shift keying (PSK). This allows for a lower bit error rate for a given modulation order and signal-to-noise ratio, at the cost of increased complexity, compared to ASK or PSK alone.[1]

Quadrature amplitude modulation (QAM) can be considered a subset of APSK because all QAM schemes modulate both the amplitude and phase of the carrier. Conventionally, QAM constellations are rectangular and APSK constellations are circular, however this is not always the case. The distinction between the two is in their production; QAM is produced from two orthogonal signals. The advantage of APSK over conventional QAM is a lower number of possible amplitude levels and therefore a lower peak-to-average power ratio (PAPR).[2] The resilience of APSK to amplifier and channel non-linearities afforded by its low PAPR have made it especially attractive for satellite communications, including DVB-S2.[3]

A modified constellation diagram of 16-APSK. Typically 16-APSK will have 15 degree phase offset on the outer ring, which is not depicted here. Symbols can be easily distinguished from each other and, moreover, varying of the space between rings is a way to counteract transmission distortions.[4]
  1. ^ Thomas, C; Weidner, M; Durrani, S (February 1974). "Digital Amplitude-Phase Keying with M-ary Alphabets". IEEE Transactions on Communications. 22 (2): 168–180. doi:10.1109/TCOM.1974.1092165. Retrieved 11 June 2021.
  2. ^ Ershov, A.N., Berezkin, V.V., Petrov, S.V., Petrov, A.V. and Pochivalin, D.A., 2018. Features of Calculation and Design of High-Speed Radio Links for Earth Remote Sensing Spacecraft.
  3. ^ De Gaudenzi, Riccardo; Guillén i Fàbregas, Albert; Martinez, Alfonso (19 May 2006). "Turbo-coded APSK modulations design for satellite broadband communications". International Journal of Satellite Communications and Networking. 24 (4): 261–281. doi:10.1002/sat.841. S2CID 9245178. Retrieved 11 June 2021.
  4. ^ "Standard + Customized APSK Schemes For Satellite Transmission" By Donald Vanderweit, Agilent Technologies, Inc.

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