Ergodic Secrecy Rate of Optimal Source Selection in a Multi-Source System with Unreliable Backhaul

Abstract: The use of multiple source nodes with wireless backhaul is considered for secrecy enhancement through source node selection in future wireless networks. The ergodic secrecy rate (ESR) of {optimal source node selection in the presence of multiple eavesdroppers} over independent non-identically distributed (INID) Rayleigh fading channels is evaluated in closed-form. At high signal-to-noise ratio (SNR), {the ESR is expressed as a simple weighted summation where each term relates to the contribution of an individual source and eavesdropper}. An asymptotic analysis shows the effect of the system parameters and backhaul reliability on the performance. {The proposed method can provide a generalized solution for the ESR of optimal \textit{transmit antenna} selection in multi-antenna systems, optimal \textit{source node} selection, and optimal \textit{relay selection} with or without unreliable backhaul.