Research on energy detection algorithm in cognitive radio systems

In cognitive radio environments, nodes should have the capability to detect whether a signal from a primary transmitter is locally present or not in a certain spectrum in short detection duration. Traditional energy detection algorithm is bad in anti noise. In this paper, the detection performance of one node with fixed single threshold and double threshold is investigated firstly in the circumstances of noise average power with constant and fluctuation in short time. Detection performance is sensitive to noise. To the characteristic, new energy detection algorithms based on cooperative and dynamic threshold are presented. Simulations show that the proposed schemes outperform traditional algorithms, and cooperative detection is optimal. Cooperative detection scheme improved antagonism of noise average power fluctuation in short time and got a good detection performance as long as increasing the number of cooperative users. In other words, the proposed scheme enhanced the robust of against noise and improved the capacity of spectrum sensing.