Performance Analysis of Local and Cooperative Spectrum Sensing in Cognitive Radio Networks

Cognitive radio (CR) has recently been identified as a promising technology to solve the spectrum inefficiency problem. CR users or secondary users (SUs) need to sense the presence of primary users (PUs) constantly and rapidly to utilize their unused spectrum. However, detection is compromised when a user experiences shadowing or fading effects. In such cases, the user cannot distinguish between an unused band and a deep fade. So, cooperative spectrum sensing is proposed to improve sensing performance. In this paper, we analyze the different spectrum sensing schemes with different fusion rules and their comparative behavior has also been studied. Moreover, the relationship between the throughput and sensing time in local and cooperative spectrum sensing has been investigated for PU protection and SU spectrum utilization mode. We also observe that average channel utilization depends on the number of cooperative users under PU protection scenario. The analytical results show that cooperative spectrum sensing employing OR rule has better performance than other fusion rules as well as non-cooperative scheme.