Cluster based cooperative sensing:-A survey

The complexity of wireless system requires a careful design, especially related to bandwidth and energy efficiency. The energy efficiency is getting more and more on importance, due to increasing penetration of various wireless systems in different battery-oriented applications, as well as due to the more conscious global view on the need for “greening the Earth”. Bandwidth efficiency is very important parameter, because it relates to frequency spectrum, which is naturally limited resource. The cognitive radio has been proposed as the future technology to meet the ever increasing demand of the radio spectrum by allocating the spectrum dynamically to allow unlicensed access on non-interfering basis. Cooperative spectrum sensing has been proposed to combat the multipath fading, shadowing and receiver uncertainty problem improving the detection performance by exploiting spatial diversity but at the cost of increase in cooperation overhead such as extra sensing time, delay, energy and operations devoted to cooperative sensing. Cluster based cooperative sensing can improve the performance and reduce the computational cost. In recent years, many methods of cooperative spectrum sensing have been proposed based on the clustering technique. In this paper, we provide an extensive review of cluster-based cooperative spectrum sensing.