Mobility Improves the Performance of Collaborated Spectrum Sensing

Spectrum sharing is a promising technology to solve the problem of the shortage and low utilization of spectrum resources in future mobile communication systems. Spectrum sensing, as a critical step to discover the available spectrum holes in spectrum sharing, attracts full attention in academia and industry. The collaborative spectrum sensing allocates sensing tasks to secondary users (SUs), such that the spectrum opportunity of SUs can be guaranteed. However, the impact of mobility on the collaborative spectrum sensing is still unknown. In this paper, we study the effects of mobility on the performance of collaborative spectrum sensing. The multi-user diversity introduced by mobility is applied in the collaborative spectrum sensing, and the performance of spectrum sensing is improved. The detection time and spectrum opportunity of SUs are derived with closed-form. We discover that when exploiting the mobility of SUs, the detection time of SUs is reduced and the spectrum opportunity of SUs is improved. Thus the performance of spectrum sensing and spectrum sharing can be improved. This paper provide fundamental guidelines for the design of spectrum sensing mechanisms in the mobile environment.