Analysis of a Hybrid Overlay/Semi-Passive Backscattering Spectrum Access in Cognitive Radio Networks

In this paper, we consider a cognitive radio networks with secondary users that can choose either to access the idle licensed channel with overlay mode or access the busy licensed channel with semi-passive backscattering mode. A queueing model with heterogeneous service rates is used to derive closed-form expressions for the average number of secondary users in the network and the expected system time for each secondary user. Numerical results are presented to evaluate the system performance improvement due to applying this new setting compared to overlay-only mode and backscattring-only mode. Simulation results are also given to verify the analytical results.