Spatial-temporal Opportunity Sensing Based on Throughput Loss in Spectrum-heterogeneous Cognitive Radio
Li Xiao-qiang① Zhou Qi② Rui Mao-hai③ Li Ying②
①(Institute of Communications Engineering, PLA University of Science and Technology, Nanjing 210007, China) ②(Institute of China Electronic System Engineering Corporation, Beijing 100141, China) ③(Communications Training Base of the General Staff Headquarters, Zhangjiakou 075100, China)
Abstract：Spectrum sensing is a key technology to enable dynamic spectrum access in Cognitive Radio (CR). To ensure that primary users are properly protected while maximizing the performance of secondary users, most related work considers the metrics of probabilities of missed detection and false alarm for determining optimal spectrum sensing parameters. However, these metrics only take account of the collision probability between primary user and secondary user to measure the performance impact on primary user. Since it fails to consider the impact of intensity of interference, it only adopt to homogeneous spectrum environment. In heterogeneous spectrum environment where the access opportunities of secondary user are differed by its positions, it can not?maximize the spectrum utilization?efficiency. So, in this paper, a new metric, throughput loss is proposed for spatial-temporal opportunity sensing firstly. Throughput loss is the average throughput loss percentage of primary user due to secondary user accesses the authorized spectrum. It is a comprehensive metric measuring impact of secondary user on primary user, and contains the collision probability and intensity of interference of two factors. Then secondary?user throughput?optimization problem based it is addressed. Finally, theoretical analysis and numerical simulations show that the new spectrum sensing technology proposed in this paper improves significantly the spectrum utilization efficiency compared with some traditional sensing technologies.
2014, Vol. 36 
