Spatial-Temporal Spectrum Access Analysis for Multi-Channel Mobile Cognitive Radio Networks

Abstract

Cognitive radios have demonstrated its ability in improving spectrum efficiency by accessing licensed spectrum bands opportunistically. Along with the popularity of mobile broadband devices in future mobile communications, research for cognitive radios with mobility will be paid more and more attentions. In this paper, a multi-channel cognitive radio network with mobile secondary users is investigated. Based on the reality that the primary licensed channels have different available states on spatial and temporal dimensions for secondary users, we analyze the spatial-temporal spectrum utilization rate and derive the network throughput of secondary users combined with successful probability of wireless transmission. Finally, through maximizing the throughput we obtain the optimal spectrum access strategy. Numerical results show the effect of the system parameters on the proposed strategy and verify our proposed strategy outperforms other strategies such as equiprobable, inverse proportional and random access strategies.