Nonlinear Distortion Effects in Secure Energy Efficient MIMO Systems.

Energy efficiency and physical layer security are important features in nowadays wireless communication systems. A secure Multiple-Input Multiple-Output (MIMO) point-to-point communication was previously studied, where higher order modulation symbols are decomposed into a sum of low order modulation symbols. These components are then separately amplified and transmitted over a communication channel. Even though the components were processed to have lower envelope fluctuations, the oversampling process increases their dynamic range so that it can have an impact in the Peak-to-Average Power Ratio (PAPR), meaning that the signals are prone to Non-Linear Distortion (NLD) effects in the amplification stage. These effects can cause the degradation of the system's performance in different aspects like energy efficiency or the decoding process. In this paper, we implement the symbol decomposition method along with oversampling and analyze the non-linear distortion effects by evaluation the system's model performance. The BER (Bit Error Rate) parameter is simulated considering the effectiveness of the IB-DFE (Iterative Block Decision Feedback Equalization) receiver.