Joint optimization of feedback overhead and detection threshold for cooperative spectrum sensing in LTE cognitive systems

For the cooperative sensing technique of cognitive radio, the detection threshold is very significant to the system performance. And the feedback overhead is also important owing to the limited bandwidth of the control channel. The two factors were discussed in many previous literature, respectively. In this paper, both the detection threshold and the feedback overhead are considered and joint optimization schemes are proposed to maximize the average throughput of secondary users under the constraints of the false alarm probability (FAP) and the missing detection probability (MDP). The optimization problems are formulated both in one-threshold and two-threshold coarse sensing systems. And the performance of the proposed schemes are compared with the schemes only concerning the optimization of the feedback overhead. Simulation results show the advantage of the joint optimization schemes. It is also found that the joint optimization scheme in two-threshold coarse sensing system outperforms that in one-threshold coarse sensing system in average throughput performance.