Intelligent Reflecting Surface-Aided Spectrum Sensing for Cognitive Radio

Spectrum sensing is a key enabling technique for cognitive radio (CR), which provides essential information on the spectrum availability. However, due to severe wireless channel fading and path loss, primary user (PU) signals received at CR or secondary (SU) can be practically too weak reliable detection. To tackle this issue, we consider in letter new intelligent reflecting surface (IRS)-aided scheme CR, by exploiting large aperture passive beamforming gains of IRS boost PU signal strength SU facilitate its sensing. Specifically, dynamically changing reflection over time according given codebook, reflected power varies substantially SU, utilized opportunistic Furthermore, propose weighted energy detection method combining values different reflections, significantly improves performance. Simulation results validate performance gain proposed IRS-aided scheme, as compared benchmark schemes.