Performance Evaluation of APK Modulation for Nonlinear Satellite Communication Channel

There is interest in getting high bit rate over satellite channel containing a nonlinear power amplifier. This paper studies different orders of amplitude phase shift keying (APK) modulation, 16-ary quadrature amplitude modulation (QAM) and predistortion considerations over the satellite power amplifier. Satellite transmission channel has been modelled to simulate and compare between methods for a better performance. The Saleh Model and Ghobni model has been selected from literature measurements of the travelling-wave tube-amplifier (TWTA) and solid state-power-amplifier (SSPA) respectively; however, in the simulation the TWTA gives better performance than SSPA in most modulation techniques. It was investigated with predistortion and without predistortion the best modulation constellation performance under nonlinear communication channel.