In this paper, we analyze pilot contamination (PC) attacks on a multi-cell massive multiple-input multiple-output (MIMO) network with correlated pilots. We obtain correlated pilots using a user capacity-achieving pilot sequence design. This design relies on an algorithm which designs correlated pilot sequences based on signal-to-interference-plus-noise ratio (SINR) requirements for all the legitimate users. The pilot design is capable of achieving the SINR requirements for all users even in the presence of PC. However, this design has some intrinsic limitations and vulnerabilities, such as a known pilot sequence and the non-zero cross-correlation among different pilot sequences. We reveal that such vulnerabilities may be exploited by an active attacker to increase PC in the network. Motivated by this, we analyze the correlated pilot design for vulnerabilities that can be exploited by an active attacker. Based on this analysis, we develop an effective active attack strategy in the massive MIMO network with correlated pilot sequences. Our examinations reveal that the user capacity region of the network is significantly reduced in the presence of the active attack. Importantly, the SINR requirements for the worst-affected users may not be satisfied even with an infinite number of antennas at the base station.

中文翻译：

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多小区多用户大规模MIMO网络中的导频污染攻击

在本文中，我们分析了对具有相关导频的多小区大规模多输入多输出 (MIMO) 网络的导频污染 (PC) 攻击。我们使用实现用户容量的导频序列设计来获得相关导频。这种设计依赖于一种算法，该算法基于所有合法用户的信号干扰加噪声比 (SINR) 要求设计相关导频序列。即使在 PC 存在的情况下，试点设计也能够满足所有用户的 SINR 要求。然而，这种设计有一些固有的局限性和弱点，例如已知的导频序列和不同导频序列之间的非零互相关。我们发现，主动攻击者可能会利用此类漏洞来增加网络中的 PC。受此启发，我们分析了可被主动攻击者利用的漏洞的相关试验设计。基于此分析，我们在具有相关导频序列的大规模 MIMO 网络中开发了一种有效的主动攻击策略。我们的检查表明，在存在主动攻击的情况下，网络的用户容量区域显着减少。重要的是，即使基站有无限数量的天线，对受影响最严重的用户的 SINR 要求也可能无法满足。