Anti-Eavesdropping Scheme Based on Random Mapping for GSM-MBM Systems

Media-based modulation (MBM) is a recently proposed modulation scheme which has the advantages of increased spectral efficiency and improved performance. In this paper, a physical layer security (PLS) scheme is proposed for the multiple-input multiple-output (MIMO) media-based modulation system using generalized spatial modulation (GSM) to resist the passive eavesdropping from a multiple-antenna eavesdropper. Secure mapping rules between the information bits and the transmit patterns are designed based on the abundant legitimate channel realizations of the MIMO MBM system. Due to the independent fading of the legitimate link and the eavesdropping link, the designed mapping rules are unavailable and appear random to the eavesdropper. Therefore, the correct detection of the information bits at the eavesdropper is prevented, which is validated through bit error rate (BER) analysis and simulations. The ergodic secrecy rate is analyzed and a tight closed-form approximation is derived. Simulation results show that the proposed secure GSM MBM scheme outperforms the existing secure MBM schemes without consuming jamming power or requiring eavesdropper’s channel state information.