Research On Optimization For Cooperative Spectrum Sensing Time In Cognitive Radio Networks

As far as we know, cognitive radio technology plays a key role for the wireless communications business, it has a profound and great impact on the development of communications. With the pace of the times, wireless communications business also gets swift and violent development, however the problem of the lack of the limited spectrum resource and the incomplete using of spectrum for stationary distribution become more and more serious. Fortunately, Cognitive radio technology appears in the world, it alleviate to this problem effectively. It uses the correlation spectrum sensing and management technology, without affecting the authorized users under the premise, put forward the idea of sharing spectrum resources, so that the spectrum utilization rate is improved.This article mainly aims at the problems of optimization sensing time of cooperative spectrum in cognitive radio technology. Firstly, the atricle introduced some the basic knowledge of cognitive radio technology and key technology, then mainly discusses two problems:In view of the traditional spectrum detection technology do not take the specific conditions of channel into account, based on each channel’s specific conditions is presented in this paper, take adaptive channel status detection strategy individually. First we can obtained the weight through the statistic of channel condition for the channel utilization.Here the so-called weight equals to the channel’s unoccupied probability.The weight characterize the condition of channel is reasonable.If the weight is very small, which implies channel unoccupied condition is often, we increase sensing time to decrease the probability of false alarm, that’s can avoid the waste of available opportunity. When the weight is very large, we decrease sensing time to reduce the consumed time of ineffective searching. At the same time in order to guarantee the high quality channel detection we set the limit parameter. Through the establish such a model, to optimizing the overall channel detection time. The simulation results show that the adaptive channel status of spectrum detection time reduction. At the same time as the limit parameter increases, the average search time increases.In traditional cluster-based cooperative spectrum sensing technology scheme, cognitive users devide into several clusters and selected the cluster head which collects message and sends it to the fusion center. However, the reliability of different cluster members are various, so the fusion center process sensing data are more time-consuming, inefficient, and increased cognitive user data processing burden. This article through the traditional cluster-based cooperative spectrum sensing, put forward the double threshold in order to reduce the need for processing data quantity, thereby improving the perception of time. Compare the the bit error rate under the cognitive users send message to cluster head and which sends it to the fusion center directly, selected the cluster members. According to Wald’s equation, get the average number of samples that the cluster head required to report to the fusion center. The simulation results show that the sensing time saving rate, it has been greatly improved. At the same time, with the traditional cluster-based cooperative sensing techniques are compared, have also been reduced sample number.