NOMA场景下基于双阶段训练的导频污染攻击检测和去污方案  

Against Pilot Contamination Attack with Two-stage Training for NOMA Systems

作　　者：彭薇[1,2] 吴亚莹 陈达[1] 罗锴 王巍[1] PENG Wei;WU Yaying;CHEN Da;LUO Kai;WANG Wei(Huazhong University of Science and Technology,Wuhan 430074,China;Shenzhen Huazhong University of Science and Technology Research Institute,Shenzhen 518057,China;Sun Yat-sen University,Shenzhen 518107,China)

机构地区：[1]华中科技大学,湖北武汉430074 [2]深圳华中科技大学研究院,广东深圳518057 [3]中山大学,广东深圳518107

出　　处：《移动通信》2024年第10期23-31,48,共10页Mobile Communications

基　　金：国家自然科学基金面上项目“Sub-6G频段无线信道参数获取与特征分析理论及方法研究”(62171192),“毫米波频段上FBMC原型滤波器设计理论与方法研究”(62071195);深圳市科技局基础研究项目“5G通信频段高移动场景信道预测方法研究”(JCYJ20210324135206018);深圳市科技局国际合作项目“B5G通信系统信道状态信息智能获取理论与方法研究”(GJHZ20220913143401002)。

摘　　要：导频污染攻击是攻击者使用与合法用户一致的导频去破坏合法用户的导频训练过程,是物理层中一种主动窃听手段。针对于目前基于调整导频结构的导频污染攻击研究在实际场景中的应用效果较差以及信道去污缺乏对角度域重叠概率探究的问题,提出可用于非正交多址接入环境的基于双阶段训练的导频污染攻击检测算法和基于空间特征的信道去污方案:首先利用接收信号在不同训练阶段正交投影结果的概率密度分布得到攻击检测结果;再利用信道能量在基站天线数较大时只会集中在少数几个方向上,并且不同用户信道在角度域上不可能存在重叠的理论依据实现信道去污。仿真实验表明,相较于基于随机矩阵理论的检测算法[10]和最小描述长度检测算法[11],提出的导频污染攻击检测方法在不同信噪比和导频长度下检测能力都得到显著改善;相较于基于特征值分解的盲信道估计算法[21]和线性最小均方误差信道估计算法[29],提出的信道去污方法在不同信噪比下去污性能上也得到了显著提升。Pilot contamination attack is an active eavesdropping method at the physical layer,where the attacker disrupts the pilot training process by using the same pilot as the legitimate user.The current research on pilot contamination attack detection mainly focus on modifying the pilot structure,however,it has poor performance in practical application scenarios and lacks the consideration of the overlapping probability in angel domain.To solve these problems,a pilot contamination attack detection method based on two-stage training and a spatial feature-based channel decontamination method are proposed for non-orthogonal multiple access scenarios.Firstly,the attack detection results are obtained by the probability density function of the orthogonal projection results of the received signal at different training stages.Secondly,due to the fact that the channel energy with large number of base station antennas is only concentrated in a few directions and different user channels cannot overlap in the angle domain,the channel decontamination can be achieved.Simulation experiments show that compared with the detection algorithms based on random matrix theory and minimum description length,the proposed pilot contamination attack detection method significantly improves the detection performance under various signal-to-noise ratios and pilot lengths.Also,compared with blind channel estimation algorithms based on eigenvalue decomposition and linear least mean square Error channel estimation algorithm,the proposed channel decontamination method improves the decontamination performance under different signal-to-noise ratios.

关 键 词：物理层安全 导频污染攻击 NOMA 攻击检测 信道去污 

分 类 号：TN929.5[电子电信—通信与信息系统]