Secrecy Outage Analysis of RIS-Assisted MIMO System With Randomly Located Eavesdroppers

In this letter, we investigate the secrecy performance of a reconfigurable intelligent surface (RIS) assisted multiple-input multiple-output (MIMO) communication network in the presence of randomly positioned eavesdroppers. We derive closed form expressions for the beamforming vector of the base station (BS) and the phase shifts of the RIS. Considering the colluding wiretap strategy, the secrecy outage probability is obtained in closed form by using the theory of stochastic geometry. Numerical results confirm the effectiveness of our theoretical analysis, demonstrating that increasing the number of BS antennas and RIS elements can significantly enhance the secrecy performance of the system.