Performance analysis and optimization of secure generalized spatial modulation

Artificial noise (AN) is considered as a new physical layer technology to improve the security of wireless systems. In this paper, we investigate secure transmission of AN-aided generalized spatial modulation (GSM), which maintains the same hardware requirements at the transmitter as the conventional GSM. In order to further improve the jamming intensity of conventional AN scheme, we propose an Euclidean distance optimized AN (ED-AN) scheme by minimizing the Euclidean distance between the transmit signal and the jamming signal, which also avoids the power waste of conventional AN scheme. The secrecy capacities of both the AN-GSM and EDAN-GSM schemes are analyzed, and the optimal power allocation of AN-GSM is further investigated by maximizing the secrecy capacity. Furthermore, the upper bounds of the theoretical bit error rates (BERs) of both the legitimate receiver and the illegal eavesdropper over the Rayleigh fading channel are derived. Simulation results validate our derived analysis and demonstrate that the ED-AN scheme offers better secrecy and BER performance