Optimization of cooperative secondary users in cognitive radio networks

In this paper, we identified the optimal number of secondary users in a cooperative spectrum sensing by maximizing the energy efficiency. We obtain the mathematical expressions and simulation results for the optimal number of secondary users using OR and AND fusion rules. We conducted the simulation for both OR and AND rules in two categories, One by keeping signal to noise ratio constant and second by keeping the detection threshold constant. Based on the analysis we showed that the performance obtained for OR rule is better than the AND rule. We hope that our results will be useful for improving the energy efficiency in identifying the un-utilized spectrum.