Technology Of Spectrum Detection Based On Energy Detection

Cognitive radio (CR) can effectively resolve the current issue of shortage of spectrum resources through improving the spectrum of resource utilization. Technology of spectrum sensing, spectrum management and sharing, and power control is a new research topic of wireless communication. In this paper, spectrum sensing technology is studied. The main contents are as follow:Two levels of existing techniques on spectrum sensing in CR are described: single node spectrum sensing and multi-node cooperative spectrum sensing. The mathematical models of the spectrum sensing technology which mentioned above are established. The method of energy detection is selected, and adopted by each CR user of cooperative sensing, thereby minimizing complexity of cooperative system.In the AWGN channel, methods of energy detection and multi-nodes cooperative sensing based on hard-decision and soft-decision are studied. The mathematical simulation models of methods mentioned are establish on the platform Matlab, through comparative analysis of the simulation curves, the corresponding results are given, and supply a basis for further research on detection in fading channel.The performance of single-node spectrum is poorer than multi-node cooperative spectrum sensing due to shadows, shading and other effects. The single-threshold of cooperative detection is difficult to determine, and method of the Equal Gain Combing (EGC) increases the system burden, because it needs transmitting all information from every CR user. The method of double-threshold collaborative detection is applied to Rayleigh channel, focuses on the mathematical modeling and simulation. By selecting two different thresholds, the information could process by different algorithms. Computer simulation results show that double threshold method over Rayleigh channel can improve the detection performance and reduce the system unnecessary burden.