Opportunistic Energy-Aware Channel Sensing Schemes for Dynamic Spectrum Access Networks

Spectrum sensing, which finds spectrum opportunities for the secondary users (SUs), plays a pivotal role in the cognitive radio-based dynamic spectrum access networks. In this paper, we develop the optimal spectrum sensing scheduling for the energy-constraint cognitive radio networks where the SUs are not synchronized with the primary users (PUs). First, we develop the analytical models to investigate the tradeoff between the sensing energy consumption and the missed spectrum opportunity for the SUs. Second, building on top of the analytical models, we derive the optimal spectrum sensing scheduling which minimizes the sensing energy consumption while confining missed spectrum opportunity to a predefined threshold. Third, we take into account the sensing errors, namely, missed detection and false alarm, in the analytical models. In particular, we analyze the impact of the sensing errors on the energy consumption and missed spectrum opportunity when adopting the two-threshold based sequential sensing policy. Finally, we conduct simulations to validate and evaluate our proposed scheme.