该文研究在采用波束赋形和人工噪声的物理层安全方案中利用人工噪声提高合法接收端性能。发送端根据发送符号和信道系数,判断人工噪声是否对合法接收端的信号检测有益,并针对有益噪声和无益噪声分别设计不同的噪声波束赋形矢量。通过利用有益噪声,在不改变窃听端接收信噪比的条件下,合法接收端的信噪比有较明显的提高。对误比特率和保密容量进行理论分析和仿真,结果显示,与传统的人工噪声方案相比,所提方案可提高合法接收端的性能,改善保密容量。
A physical layer security scheme is studied, which employs the advantage of artificial noise to improve the performance of legitimate user for multiple antenna systems using beamforming technology and artificial noise. Based on the transmitted symbols and channel coefficients, the sender determines whether or not the artificial noises are beneficial to the signal detection at the legitimate receiver. Then, beamforming vectors are designed accordingly. By taking advantage of useful noise, the signal to noise ratio at the legitimate receiver is improved effectively while that at the illegal receiver will remain the same. The bit error rate and the secrecy capacity are analyzed and simulated. The results demonstrate that the proposed scheme can improve the performance of the legal receiver and enhance secrecy capacity.