Research on spectrum assignment in electric cognitive radio networks

As an important part of communication networks for Smart Gird, electric wireless networks play a significant role in the development of Smart Grid. Shortage of frequency resource is a limited factor for the evolution of wireless network, although some frequency around 230MHz are indicated to electric wireless networks, it can´t meet all the needs of existing services, spectrum scarcity weaken the performance of the electric wireless communication system. Cognitive radio (CR) can exploit the unused portions of spectrum for authorized users in an opportunistic manner by spectrum sensing which will improve the efficiency of spectrum. Combined with the development status and characteristics of electric wireless communication system, we present the system architecture of electric cognitive radio network (E-CRN) which can take full advantage of the idle frequency resources and solve the problem of frequency scarcity. Spectrum assignment is a key technology of CR, the results of assignment will affect the spectral efficiency and fairness directly. Comprehensive consideration of spectrum efficiency and fairness, method of spectrum assignment for electric cognitive radio network (E-CRN) is presented, which not only give the three decision factors of fairness and calculation method, but also define a new spectrum assignment criteria by interaction participation between cognitive base station and cognitive users. The result obtained from numerical experiments show that the proposed algorithm effectively improve the spectrum utilization with a fair distribution and will satisfy more requirements of wireless services for Smart Grid.