Pilot Contamination Attack Detection for NOMA in 5G mm-Wave Massive MIMO Networks

Power non-orthogonal multiple access (NOMA) has been considered as a new enabling technology in 5G communication. In this paper, we introduce the problem of pilot contamination attack (PCA) on NOMA in millimeter wave (mmWave) and massive MIMO 5G communication. Due to the new characteristics of NOMA such as superposed signals with multi-users, PCA detection faces new challenges. By harnessing the sparseness and statistics of mmWave and massive MIMO virtual channel, we propose two effective PCA detection schemes for NOMA tackling static and dynamic environments, respectively. For the static environment, the problem of PCA detection is formulated as a binary hypothesis test of the virtual channel sparsity. For the dynamic environment, the statistic of the peaks in the virtual channel is leveraged to distinguish the contamination state from the normal state. A peak estimation algorithm and a machine learning based detection framework are proposed to achieve high detection performance. To further optimize the proposed scheme, a feature selection algorithm and an optimization model considering the detection accuracy and detection delay are presented. Simulation results evaluate and confirm the effectiveness of the proposed detection schemes. The detection rate can approach 100% with 10(-3) false alarm rate in the static environment and above 95% in the dynamic environment under various system parameters.