Analysis of cooperation for relay based spectrum sensing in cognitive radio networks

In this paper, we analyze the effect of cooperation for spectrum sensing based on relay with equal gain combining in cognitive radio networks. The performance of energy detection in cognitive radio network over a number of cognitive radio users is evaluated. The probability of detection and probability of false alarm are calculated and simulated. We found that when the square of the sum of the gains at the cognitive users increases to a certain degree, more users and larger gains may not lead to higher detection probability. In addition, we provide the optimal guidelines to help the system to select the cooperative users to guarantee detection performance in a practical radio environment. For the maximum probability of detection, collaboration of only a subset of available cognitive users is required.