Research Of Spectrum Sensing Optimization Problem In Centralized Cooperative Networks

In cognitive radio network, the available throughput is usually an evaluation index of access strategy and sharing strategy. The spectrum sensing optimization problem which is to maximize the throughput has become the research hotspot in recent years. The throughput in cooperative sensing network is related to a variety factors such as system parameters and sensing parameters. So improving the throughput is a complicated joint optimization problem. In this paper, the joint optimization problem in centralized cooperative sensing network is researched. The main contents are as follows:1) In centralized cooperative sensing network based on narrow band, the multi parameter optimization problem that is jointly optimize the sensing time, decision threshold, number of cognitive radios in collaborative and k is formulated in order to maximize the throughput while protecting the primary user from harmful interference.2) Based on the optimization model considering the influence of the reporting channel, the hierarchical optimization is conducted. The effect of the sensing time, decision threshold, number of cognitive radios in collaborative and k on joint optimization is analyzed by simulation. The simulation results demonstrate that when the joint optimization strategy proposed is employed, the throughput of the secondary network is improved. And when the optimal k value is used, the robustness is strengthened.3) In centralized cooperative sensing network based on multiband, the optimization problem which is referred to as multiband sensing time adaptive joint detection is formulated. It is to jointly optimize the sensing time and individual detector threshold in order to maximize the throughput while protecting the primary network from harmful interference. The optimization problem can be transformed into a convex optimization problem in the regime of low probabilities of false alarm and miss by theoretical derivation. Then, the interior point barrier method can be adopted to solve this problem. The simulation results verify the correctness of the algorithm and demonstrate that the multiband joint detection algorithm with cooperation results in higher throughput than the algorithm without cooperation.