Jammer Selection in Heterogeneous Networks with Full-Duplex Users

In this paper, we investigate the physical layer security for heterogeneous networks (HetNets), where the confidential message transmitted to each legitimate user can be eavesdropped by multiple eavesdroppers. To enhance the secrecy performance, we introduce friendly jammers and full duplex users in our model. We propose a jammer selection scheme based on average user received jamming power. The jammers whose interference power on the scheduled users less than a threshold are selected to transmit independent artificial noise to confound the passive eavesdroppers. Furthermore, the scheduled users try to jam the eavesdroppers around using full duplex capacity. Using the tools from stochastic geometry, we derive the theoretical analyses of user connection probability and secrecy probability. In particular, the locations of selected jammers are modeled by a Poisson hole process instead of more popular homogeneous Poisson point process. Our analytical results show a good agreement with the simulations. The ergodic secrecy rate in our scheme outperforms that in the traditional HetNets.