RIS Aided Residual Energy: PS and TS Mode Harvesting in Cooperative Spectrum Sensing

This work studies performance comparison on radio frequency ($\mathbf{R F}$) energy harvesting ($\mathbf{E H}$) in power splitting (PS) and time-switching (TS) modes in reconfigurable intelligent surfaces (RIS)-aided cooperative spectrum sensing (CSS). CSS model considers multiple primary user (PU) nodes and a single PU emulation attacker (PUEA) node. A distant dependent model of reflected channel gain in RIS antenna is developed for calculating the harvested residual energy (RE). The primary objective is to maximize the total RE while meeting a predefined detection and false alarm probabilities of PU along with the individual secondary user’s (SU’s) energy causality constraint. Simulation results show the efficacy of the proposed work due to the involvement of RIS antenna on total RE, as gain of about 45% and 38.97% for PS and TS modes compared to the existing works while maintaining the above mentioned constraints. Performance of RE with the change in the placement of RIS antenna near/far to PU is analyzed for both PS and TS modes.