Confidence Based Cooperative Multi-dimensional Spectrum Sensing Technologies

With the development of great requirement of wireless communication services,the new Wireless Communication Technology standards are springing up rapidly. Thewireless spectrum resource is in short supply, whereas demand of new technologiesand new business for wireless spectrum resource is huge. Thus the contradiction is in-creasingly conspicuous. Cognitive radio technology has the ability to opportunisticallyaccess the channel without a usage license, such that the frequency spectrum utilizationis greatly improved. The spectrum sensing technology is a key technology in cognitiveradio for finding the spectrum access opportunities—spectrum holes and avoidinginterference to the primary user. Also the technology is very challenging.Multi-node cooperative spectrum sensing technology is able to overcome the per-ceived performance reduction of the single node spectrum sensing technology afectedby the fading channel and shadow efect. In cooperative spectrum sensing, secondaryusers can obtain cooperative diversity gain under the exchange and integration of per-ceptual information, hence the sensing performance of the whole cognitive radio sys-tem is raised. However in cooperative spectrum sensing, the amounts of the infor-mation contributed to Fusion Center by diferent secondary users are diferent, that isthe level of confidence is diferent with the sensing information of diferent secondaryusers. This paper studied sensing data fusion problem based on the level of confi-dence of secondary users in data fusion scheme of cooperative sensing, and propose adistinctive quantification method of local perception data.As the signals of wireless communication system have multiple dimensions, thespectrum holes have multiple dimensions. Frequency is the inherent dimension of spec-trum hole, there are two other basic dimensions: time and space. For time dimensionbesides. The goal of spectrum sensing technology is improving the accuracy of sensing(reduce false-alarm probability and false dismissal probability) and sensing speed (findspectrum holes and backof from the channel as soon as possible). According to se- quential probability ratio test (SPRT), this paper proposes a sensing program based onasynchronous frame structure Global SPRT. For space dimension, this paper proposesan iterative algorithm to locate primary users, after that large scale space dimensionsensing holes could be discovered according to path loss model.The powerful network supports in cognitive radio make spectrum sensing easy.REM is just a data mode of network support, which provides local prior information ofradio magnetic environment to cognitive radio networks in certain region. This papercomprehensively studied spectrum holes of time dimension and space dimension, andproposed two establishment and updating schemes of REM.