Implementation of relay based collaborative spectrum sensing using coalitional games in wireless cognitive radio networks

Collaborative spectrum sensing is used by Secondary Users (SUs) in Cognitive Radio Networks to improve spectrum detection performance. To study its performance, Normal Collaborative Spectrum Sensing (NCSS) based on coalitional games is designed and implemented in Wireless Open-Access Research Platform. The SUs which detect weak signal from Primary Users collaborate with Cluster Head (CH) to improve the overall sensing performance indicated by sum-utility of the system. However, the test-bed implementing NCSS shows that under poor reporting channel conditions, the coalition splits and the ‘weaker’ SUs exhibit inefficient sensing performance. The proposed Relay based Collaborative Spectrum Sensing (RCSS) solves this problem by using neighboring SU with low error prone relay path to share sensing results between affected SUs and CH. Test-bed results reveal that RCSS performs better than all other collections of coalitions and it improves sum-utility by 20%, as compared to NCSS at the cost of minimal 2.3% loss in energy efficiency.