Distortion modeling and analysis for multilevel coded APSK with memoryless nonlinearity

In order to improve the bandwidth efficiency of communication systems under strict power limitation, the use of multilevel modulation together with near capacity channel coding is essential. However, such an approach is sensitive to nonlinear distortion associated with high peak-to-average power ratio (PAPR) of the resulting signals. We consider the application of the multilevel coded modulation with multi-stage decoding (MLC/MSD) over nonlinear communication channels and propose a robust unconventional set partitioning approach in conjunction with the metric adjusted to the statistical characteristics of nonlinear distortion. Numerical results show that the proposed method outperforms the system with the conventional labeling in terms of achievable average mutual information (AMI) and frame error rate (FER).