针对窃听方发送恶意导频干扰破坏系统安全性能的问题,本文将研究场景扩展到三节点MIMO(Multple-Input Multiple-Output)网络,首先分析存在恶意导频干扰时最小二乘和最小均方误差准则下的信道估计结果,并推导基于人工噪声的系统安全速率公式,得出当窃听方到达发送方的导频干扰功率大于合法接收方达到的功率时,安全速率值只能为零.然后,进一步分别研究半双工窃听方和全双工窃听方场景下的最优功率分配方案.最后,通过数值仿真分析窃听者位置、窃听者类型和干扰功率等因素对安全性能的影响.
According to the security problem caused by the malicious pilot contamination,this paper considers a threenode MIMO( Multple-Input Multiple-Output) network. First,the channel estimation results based on the least square criterion and the minimum mean square error criterion under the malicious pilot contamination are analyzed. Then by deducing the secrecy rate,we conclude that when the power of the pilot contamination from the eavesdropper is larger than that from the legitimate receiver,the secrecy rate is zero. Finally,the optimal power allocation schemes for the half-duplex and full-duplex eavesdropper are further studied,respectively. Simulation results showthe effects of eavesdropping position,eavesdropping type,jamming power and other factors on the security performance.