An Objection-Based Collaborative Spectrum Sensing for Cognitive Radio Networks

Cognitive radio transmission relies on awareness of the instantaneous spectrum utilization. Such awareness can be gained by the spectrum sensing process. To this end, collaborative spectrum sensing (CSS) is preferred as it yields more reliable results than individual sensing. However, CSS requires collaboration among all the cognitive users (CUs), which leads to a high energy consumption. This letter provides a new energy-efficient CSS scheme. The proposed scheme implies that only a CU will broadcast its local decision among the whole network. All the other CUs that have a different local decision will object to the fusion center, whereas the CUs that agree with the announced decision will stay silent. Accordingly, the fusion center will be informed of all the local decisions of the CUs and will make a global decision. An analytical study on how to select the broadcasting CU such that energy efficiency is maximized is provided. Simulation and analytic results explore the energy efficiency gain compared to the literature.