On the inherent physical-layer security of receive spatial modulation systems

This paper investigates the physical-layer security attained by Receive Spatial Modulation (RSM) scheme against potential eavesdroppers. The impact of the involved parameters on the bit error rate (BER) at the legitimate receiver and the considered eavesdropper is shown and discussed. Moreover, a hybrid scheme is proposed in order to alleviate the impact of the channel estimation errors on the achievable BER at the legitimate receiver. The proposed scheme allows the transmitter to switch between RSM and the conventional SM based on the phase of the estimated channel coefficient. Simulation results reveal that the proposed scheme can achieve at least 3 dB SNR gain as compared to the RSM, while keeping the error rate at the eavesdropper within acceptable bound.