Realization Research On High Order Modulation And Demodulation Algorithm Of16-APSK For Satellite Communication

As the capacity expansion of satellite communication system and increase ofdigital satellite broadband business, the spectrum bandwidth resources become moreand more nervous.It demands that the modulation mode has high frequency efficiencyand the utilization rate of resources. At the same time, considering the nonlinearcharacteristics of satellite channel, the choice of higher order modulation mode isworth exploring.This paper comparative analysis ber performance of16-APSK,16-QAM and16-PSK in the satellite nonlinear channel and focus on that16-APSKperformance how to adapt to the nonlinear satellite channel.Then,it research andimprove the modulation and demodulation algorithm of16-APSK. The main researchwork of this paper as follows:1．It optimize the constellation of16-APSK in the satellite channel and get amore practical radius of inside and outside round;2．On the basis of establishing mathematics model of non1inear influence factorfor modulation system, it comparative analysis ber performance of16-APSK,16-QAMand16-PSK in the satellite nonlinear channel. The conclusion is obtained that16-APSK is more suitable for satellite nonlinear channel. In order to compensate theinfluence of the nonlinear factor on the channels, it researches the adaptivepredistortion algorithm;3．It researches the implementation method of the modulation and demodulationalgorithm and carrier recovery algorithm and symbol synchronization of16-APSK. Itrealize the simulation system in Simulink and prove that the system design isreasonable and correct;4．It puts forward a kind of new soft demodulation algorithm and analysis theBER performance in contrast to the classical algorithm.It realize the new softdemodulation algorithm by verilog.It design the implementation scheme of16-APSKmodulation and demodulation algorithm in FPGA.