SECURING WIRELESS COMMUNICATIONS WITH ENERGY HARVESTING AND MULTI-ANTENNA DIVERSITY

This paper presents a secure wireless communication system that integrates Physical Layer Security (PLS) with Energy Harvesting (EH) to enhance both data confidentiality and network sustainability. The proposed system uniquely employs Maximal Ratio Combining (MRC) and Selection Combining (SC) techniques at the multi-antenna destination node D, which is a novel approach in EH-driven PLS systems. The system model features a source node S, powered by energy harvested from spatially distributed power stations, a multi-antenna destination node D and an eavesdropper node E within the communication range. A time-switching protocol allows the source node S to alternate between energy harvesting and secure data transmission. To improve signal quality and security, the destination node D employs Maximal Ratio Combining (MRC) and Selection Combining (SC) techniques to mitigate fading and eavesdropping risks. Analytical expressions for the Signal-to-Noise Ratios (SNRs) at the destination and eavesdropper are derived, along with the Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of these SNRs under block Rayleigh fading. We also provide an exact formulation for Secrecy Outage Probability (SOP), quantifying the likelihood of information leakage under different system configurations. The model is validated through Monte Carlo simulations, confirming the accuracy of the theoretical analysis. Simulation results highlight the impact of key parameters-energy harvesting efficiency eta, time-switching parameter alpha, number of antennas M , number of beacon nodes N and the power of beacon nodes-on Secrecy Outage Probability (SOP), offering valuable insights for optimizing secure and energy-efficient communication in wireless networks. An asymptotic analysis is also provided to characterize system performance at high SNR.