Coordinated Multi-Point Secure Transmissions in mmWave Cellular Networks

In this paper, we study the coordinated multi-point secure transmissions in mmWave cellular networks against randomly distributed eavesdroppers. We analyse and optimize security performance in terms of secrecy throughput under a stochastic geometry framework. We first introduce coordinated multi-point (CoMP) transmission schemes with and without exploiting artificial noise (AN), and then derive analytical expressions for connection outage probability (COP) and secrecy outage probability (SOP) which are used to characterize transmission reliability and secrecy, respectively. Based on the obtained analytical results, we maximize the secrecy throughput subject to an SOP constraint by jointly designing transmission rates and the power allocation of the AN scheme. Numerical results are also presented to validate the theoretical analyses and to demonstrate the security performance of our proposed transmission schemes. Interestingly, our results show that the CoMP with AN can bring a remarkable improvement for secrecy throughput particularly when facing a rigorous secrecy constraint.