Research On Collaborative Spectrum Sensing Technology In Cognitive Wireless Networks

In the recent decade, is the age of wireless network technology rapid development. Wireless network technology has brought more convenience to people’s life, make people enjoy life better. However, as more users use the portable mobile devices, and the demand for spectrum resource put forward higher requirements. However, spectrum resources shortage and low spectrum utilization greatly restrict the development of mobile communication network.Cognitive radio technology can effectively resolve the shortage of spectrum resources. Spectrum detection technology is the key to the cognitive radio technology, is the premise of spectrum management and spectrum decision-making, improve the detection probability of spectrum detection, reduce the false alarm probability is our main research topic. This paper mainly studied the variety of fusion rule, and puts forward a reliability of collaborative spectrum sensing algorithm based on the cognitive users, gives the system’s performance greatly improved.The second chapter tells the basic knowledge of the spectrum sensing technology, the classification, discussed the basic mathematical model, based on the research of the detection on the basis of signal transmitter, make everyone understand the spectrum sensing technology, the shortcoming of local spectrum sensing is discussed in the end.The third chapter firstly puts forward the concept of collaborative spectrum sensing, can make up for the shortcomings of local perception technology. Collaborative spectrum sensing fusion algorithm is introduced, discussed the "and" standards,"or" standard and rule of K, three kinds of fusion in the false-alarm probability and detection probability of analysis, and then the simulation. And analyzed based on the rule of "and" and the rule of "or" the best users of collaborative detection problem, thus obtained in Rayleigh fading channel and Nakagami channel under the optimal number of users.The fourth chapter proposes a collaborative spectrum detection method based on reliability of cognitive users, according to the user perception of sensory information reliability is different, different fusion rules. The user receives the signal energy and perception we compares two thresholds set by data fusion and then the fusion center. If not in between the two thresholds, we use "or" fusion rule; If in between the two thresholds, we use "and" fusion rule.