Decentralized cooperative spectrum sensing for Cognitive Radio Ad-Hoc Network: Hidden terminal awareness approach

In Cognitive Radio Network, secondary users opportunistically use the licensed channels to transmit data. The secondary users first conduct the local sensing to determine the unoccupied channels and then choose the satisfied channel in the available channel set to transmit. However, the sensing results might not be accurate due to many problems: channel fading or shadowing, noise, hidden primary users or the aggregated interference caused by other secondary user transmissions. In this paper, we are interested in improving the spectrum sensing performance by reducing the missed-detection sensing caused by the hidden primary user problem. Particularly, we first proposed the channel state transition diagram capturing the hidden terminal possibility and then developed a collaborative scheme to exchange the sensing result between secondary users. Based on the summarized sensing results achieved from secondary user neighbors and local sensing, each secondary will build its own channel table listing all available channels. Numerical results show that the proposed spectrum sensing scheme enhances the sensing results and the network performance.