Optimal Node Selection For Cooperative Spectrum Sensing In Cognitive Radio Networks

In cognitive radio network, spectrum sensing is always occupied as a way to sensethe existence of the primary user. Under fading circumstances, secondary users wouldapply a cooperative spectrum sensing in order to develop sensing quality. For the sake ofsensing quality and QoS requirements, the proper secondary users participating in thecooperative sensing should be carefully chosen. So in this thesis we discuss as follows as:1) at the first stage the strategy to choose proper secondary users in single channel mode;2)and secondly the strategy to assign different channels to different secondary users inmulti-channel mode. We model the two issues above into nonlinear integer programmingproblems in which the optimization objective is the system throughput and the QoS.However in the formulation of the optimization problems the primary user protection actsas the constraints. Based on branch-and-bound algorithm and GA algorithm, we proposedtwo methods to solve the two problems. At the end of this thesis it is shown by computersimulation results the sufficiency of the two algorithms.