QAM and APSK are used to meet the ever growing demand for higher data rates in bandwidth limited satellite channels whose main constraint to communication capacity is a non-linear transmitting High Power Amplifier (HPA). The inherent APSK robustness against nonlinear distortion leads to its introduction in the recent standard for Digital Video Broadcasting (DVB-S2). Power efficiency is still limited by high signal PAPR at the HPA input. Magnitude Modulation is a technique for PAPR reduction, proposed with success for QPSK. This paper shows that it is possible to use the magnitude modulation concept for the 16-APSK case, even considering the huge number of symbol combinations. The method's capability to avoid phase modulation is improved. In order to reduce look-up table computation complexity and storage requirements, the constellation symbols are vector quantized. Constellation and RRC symmetries are also explored. Experimental results show considerable gains of 80% in back-off reduction.

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Magnitude modulation,PAPR,Back-off,APSK,Satellite communications

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