Secure Uplink Spatial Modulation Enabled by IRS

To address the security issues in wireless transmission communication systems with finite-alphabet inputs, a secure uplink reception scheme based on receiver spatial modulation is proposed to ensure high security of the wireless transmission system while achieving high spectrum efficiency. The proposed scheme introduces disturbance phase updates at the transmitter end and disturbance compensation at the intelligent reflecting surface (IRS) to ensure both the spectrum efficiency and physical layer security of the wireless transmission system. This enables the legitimate receiver to correctly receive the signal at maximum power while preventing eavesdroppers from accurately intercepting the signal. In this paper, we propose two phase compensation schemes, namely, element-wise random disturbance compensation (ERDC) and group-wise random disturbance compensation. Furthermore, two eavesdropping scenarios, referred to as ideal eavesdropping and jamming eavesdropping, are thoroughly investigated and considered. We introduce the maximum likelihood detection to reliably detecte the indices of the designed receive antenna and the based-band modulated signal, and the closed-form expressions of error performance with ERDC scheme are deduced. Finally, in the simulated and numercial results, the performance analysis verifies error performance discrepancy based security performance evaluation of the proposed scheme, demonstrating its effectiveness and superiority.