动态阈值的双门限协作感知方法

随着通信技术的提高和通信应用的增多,无线频谱资源越来越匮乏.许多分配到资源的主用户利用率很低,认知无线电技术希望没有分配到资源的次用户合理使用主用户频谱来提高频谱的利用率.频谱感知技术关系到认知无线电中次用户对空闲频谱的使用机会,是认知无线电的关键技术之一.就是在已有的感知技术的基础上,提出了新的感知手段.在认知无线电网络中,不同的次用户由于与主用户距离以及自身所处环境的噪声影响不同,它们的信噪比一般是不一样的.这里采用的动态阈值的双门限协作感知方法,是对传统双门限能量感知方法的改进,通过充分考虑次用户之间的差异性来提高感知的性能.首先,根据对检测和虚警概率的要求,过滤掉一部分检测能力不满足条件的次用户.同时,每个次用户的用于能量感知的双门限会根据它们各自信噪比的不同而动态变化.通过与单门限能量感知以及传统双门限能量感知方法进行比较,可以看出本文提出的感知方法一定程度上提高了系统整体感知的性能.

Dynamic Dual-Threshold Cooperative Spectrum Sensing Method

With the improving of the communication technology and the increasing of the applications, the wireless spectrum resource becomes more and more scarce. The resources utilization rate of the primary users who has been assigned resources is low. The cognitive radio technology hope to improve spectrum utilization in a way that the second users use the the primary users' resource. Spectrum sensing is a key technology of the cognitive radio. This article is based on the existing sensing technology,and put forward a new sensing mean. In cognitive radio network, the respective signal to noise of second users are not same because that their distance to the first user and their own signal environments are different. The dynamic dual-threshold cooperative spectrum sensing method is an improvement over the traditional two-threshold energy-aware approach. It improve the sensing performance by fully considering the difference between the secondary users.It has several steps. First of all, it need to filter out some second users that do not meet the conditions, such as, the probability of detection and false alarm. Then, each second user will dynamic change its dual-threshold which is used for energy detection according to its SNR. Through comparing with the single threshold energy-aware cooperative spectrum sensing method and the traditional dual-threshold cooperative spectrum sensing method, we can find that our method has a better performance on improving the overall performance of the system than both of other two methods.