Spatial Degrees of Freedom for Physical Layer Security in XL-MIMO

This paper analyzes the key differences between the plane-wave (PW) and the spherical-wavefront (SW) models in the context of physical layer security (PLS) for extra-large (XL)-multiple-input multiple-output (MIMO) systems with multiple eavesdroppers. Both colluding and non-colluding strategies are considered for the different eavesdroppers. Results show that the propagation features associated to the SW model allow to reach higher secrecy rates, and to reduce the areas where an eavesdropper makes secure communication unfeasible.