A Secure Receive Spatial Modulation Scheme Based on Random Precoding

With the rapid growing demand for transmission rate, transmission security is becoming increasingly important. This paper proposes a novel scheme aiming at transmission security enhancement on the basis of the spatial modulation technology. In the proposed scheme, the transmitter maps the information bits to the index of a receive antenna, then a precoding vector is randomly selected in the null space of the targeted antenna. Due to the randomness of the precoding vector, it's difficult for the eavesdropper in unknown locations to detect the index of the targeted antenna using maximum-likelihood detection, hence its receiving performance can be greatly degraded compared with the legitimate receiver. Both theoretical analysis and simulation results verified the secure enhancement performance of the proposed scheme. Moreover, unlike most of the existing schemes which require that the transmitter should equip more antenna than the receiver, our scheme works well even if the transmitter has less antennas than the receiver.