부산대학교 도서관

Satellite communication has many unique merits than other communication methods. But with the development of broadband satellite communication, the effective way for managing the limited spectrum resources has been devised. Therefore as one of the solutions for improving spectrum efficiency, the high-order modulation system turns into the first choice. In satellite telecommunication system, nonlinear power amplifier should be used because of the limitation of power resources. When the bandwidth efficient modulation is combined with nonlinear power amplifier, the nonlinearity of nonlinear power amplifier causes waveform distortion as well as spectrum regrowth in side lobes, which can be interference to adjacent channels. In order to solve the above mentioned problems, M-ary APSK has been developed. In this thesis, the optimum design of constellation with minimum distance in M-ary APSK under nonlinear power amplifier has been firstly reviewed for BER performance analysis. And secondly, the origin crossing case in the transition among constellation points has been reviewed for reduction PAPR which is related with spectrum regrowth as well as signal power enhancement. And as novel method for making the conventional M-ary APAK’s PAPR lower, M-ary offset APSK has been proposed. For the analysis of BER performance as well as spectrum regrowth, the proposed 16 offset APSK was compared with 16-PSK，16-QAM and 16-APSK. Because there is no origin crossing in the transition among constellation points in M-ary offset APSK, the proposed method shows lower PAPR, lower spectrum regrowth and also better BER performance.