Optimal spectrum sensing framework for cognitive radio networks

Abstract

Abstract-Spectrum sensing is the key enabling technology for cognitive radio networks. The main objective of spectrum sensing is to provide more spectrum access opportunities to cognitive radio users without interfering with the operations of the licensed network. Hence, recent research has been focused on the interference avoidance problem. Moreover, current radio frequency (RF) front-ends cannot perform sensing and transmission at the same time, which inevitably decreases their transmission opportunities, leading to the so-called sensing efficiency problem. In this paper, in order to solve both the interference avoidance and the spectrum efficiency problem, an optimal spectrum sensing framework is developed. More specifically, first a theoretical framework is developed to optimize the sensing parameters in such a way as to maximize the sensing efficiency subject to interference avoidance constraints. Second, in order to exploit multiple spectrum bands, spectrum selection and scheduling methods are proposed where the best spectrum bands for sensing are selected to maximize the sensing capacity. Finally, an adaptive and cooperative spectrum sensing method is proposed where the sensing parameters are optimized adaptively to the number of cooperating users. Simulation results show that the proposed sensing framework can achieve maximum sensing efficiency and opportunities in multi-user/multi-spectrum environments, satisfying interference constraints.

A survey on MAC protocols for complex self-organizing cognitive radio networks

“…Most of the CR MAC protocols found in the literature assume that nodes are automatically aware of the existence of PUs (Cabric et al 2006;Jia and Zhang 2007;So and Walrand 2008;Su and Zhang 2008a;Akyildiz 2008;DaSilva and Guerreiro 2008;Jiang et al 2009;Rashid et al 2009). However, the unrealistic assumption is criticized because CR nodes cannot sense the PU presence when transmitting and PUs cannot generate interruptive signals to SUs on occupied channels.…”

Energy Detection Technique for Spectrum Sensing in Cognitive Radio: A Survey

“…Lee and Akyildiz [48], in order to solve both the interference avoidance and the spectrum efficiency problem, an optimal spectrum sensing framework is based on the maximum a posteriori probability (MAP) energy detection and its decision criterion based on the primary user activities. The PU activities can be assumed as a two state birth-death process, death rate ߙand birth rate ߚ.…”

A new perspective on spectrum sensing for cognitive sensor networks

“…where max , , and [17]. Moreover, is defined as the maximum interference ratio that the PU can tolerate.…”