基于多RIS优化的空间调制安全传输映射策略

为保证信号传输的抗窃听安全,提出了一种可重构智能表面( RIS)辅助空间调制的安全传输映射策略。 首先,发射端通过与 RIS 间的瞬时信道质量选取不同空间调制和星座调制的映射模式提升窃听难度。 为保证合法接收者的保密速率和误码率,以最大化合法接收者的信噪比为目标,优化 RIS 的位置和相移。 同时,利用梯度投影法解决 RIS 相移的非凸恒模约束问题。 仿真结果表明,在较低信噪比下,所提安全传输策略能满足接收者的性能。在瞬时映射模式下,窃听者无法正确解码窃听信息,有效地保证了系统的抗窃听安全。

Mapping-Varied Spatial Modulation for Secure TransmissionBased on Multi-RIS Optimization

In order to ensure the anti-eavesdropping security of signal transmission, a mapping-variedstrategy based on multiple reconfigurable intelligent surfaces ( RIS ) is proposed. First, based oninstantaneous channel quality between RIS and transmitter, the transmitter selects different mappingmodes of spatial modulation and constellation modulation to improve the difficulty of eavesdropping. Inorder to ensure the security rate and bit error rate of legitimate receivers, the position and phase shift ofRIS are optimized to maximize the signal-to-noise ratio of legitimate receivers. Meanwhile, the gradientprojection method is used to solve the non-convex constant mode constraint problem of RIS phase shift.Simulation results show that the proposed secure transmission strategy can guarantee the performance ofthe legitimate receiver at a lower signal-to-noise ratio. Meanwhile, in instantaneous mapping mode, the eavesdropper cannot decode the eavesdropping information correctly, which greatly ensures the anti-eavesdropping security of the system.