提出一种基于广义空移键控调制的多输入单输出系统中的物理层安全传输方案.发射端利用合法接收者反馈的信道信息对发送信号进行预处理,使合法接收者接收的来自各发射天线信号的相位对齐;同时进行相位旋转来增加星座点间的距离,从而提高合法接收者的接收性能,降低误码率.而窃听者接收到的各信号的相位仍然为随机分布,接收性能明显低于合法接收者.对合法接收者和窃听者的误比特率和保密容量进行了理论和仿真分析.理论和仿真结果表明,所提方案能明显降低合法接收者的误比特率,即使在合法信道性能比窃听信道性能要差的情况下,系统仍然能实现保密传输.
A physical layer security transmission scheme based on generalized space shift keying modulation for multiple-input single-output system was proposed. The transmitter uses the channel state information feedbacked by the legitimate user to preprocess the transmit signals. So the signals received by the legitimate user from each transmit antenna are in phase. Furthermore,the transmitter takes a phase rotation to increase the distances among the constellation points,thereby the performance of the legitimate user is improved and the error rate is reduced. However,the phase of each signal received by the eavesdropper is randomly distributed,so the performance of eavesdropper is significantly inferior to the legitimate user. Analysis and simulation are done for bit error rate of the legitimate user and the eavesdropper.It is shown that the proposed scheme can significantly reduce the legitimate user's bit error rate,even the channel performance of the legitimate user is worse than the eavesdropper,and the secure transmission can be realized.