MIMO multi-user secrecy rate analysis

In this paper, we consider the broadcast channel with confidential messages and eavesdroppers (BCCE), where a multi-antenna base station simultaneously communicates to multiple potentially malicious users, in the presence of external eavesdroppers randomly located according to a Poisson point process (PPP). By using techniques from stochastic geometry and random matrix theory, we obtain explicit expressions for the secrecy outage probability and mean secrecy rate achievable with regularized channel inversion precoding. We show that both these metrics scale as -4fe, where N is the number of transmit antennas and A_e is the density of external eavesdroppers.