A location-aware discrete region approach for spatial access opportunity analysis in cognitive radio networks

Spectrum access is an important research topic in cognitive radio networks, in which secondary users (SUs) manage to utilize the licensed spectrum bands of primary users opportunistically. However, there is a tradeoff between the access opportunities for SUs and communication constraints from primary networks. Moreover, considering the interplay among SUs sharing the limited spatial access resources, how much the access opportunity a SU can derive become complex to determine. In this paper, to protect the primary users(PUs) from the interference caused by SUs, a location-aware discrete region model for spatial spectrum access opportunities of SUs is highlighted, in which the exact value of access opportunity is quantitative as the expected allowed-transmitting number (EATN) of SUs surrounding a PU. Considering the impact of SUs transmission probability and mobility, a probabilistic analysis and a finite-state Markov chain is undertaken. Simulation results show the change rules of SUs access opportunities with parameters of primary and secondary networks, which is full of conductive in determining the deployment and operation of secondary network.