Efficient cooperative spectrum sensing for three-hop cognitive wireless relay networks

This study is concerned with cooperative spectrum sensing (CSS) mechanisms in three-hop cognitive wireless relay networks (CWRNs). The data transmission from a source to a destination is realised with the aid of two layers of cognitive radio (CR) users which are in the transmission coverage of two primary users. The authors first propose a new CSS scheme for a layer of CR users to improve the spectrum-sensing performance by exploiting both local decisions at the CR users and global decisions at the fusion centre. Particularly, the probabilities of missed detection and false alarm for a practical scenario where all sensing, reporting and backward channels suffer from Rayleigh fading are derived.