Detection and Leasing of Joint Space and Spectrum Opportunities by Multiple Secondary Network Operators in Cognitive Radio Systems

Abstract

The fifth generation (5G) wireless networks are expected to achieve 1000 times higher capacity compared to the fourth generation (4G) wireless networks. This implies that maximizing the spectrum efficiency will be one of the key issues to 5G systems. In this paper we consider the problem of detecting and leasing the joint space and spectrum opportunities by a number of secondary network operators (SNOs) in a cognitive network. With the exploitation of an antenna array equipped at each SNO, the whole space in the view of the array can be sliced by multiple partially overlapped beams for each narrowband channel. We derive the energy detection probability of the primary users (PUs) at a given beam for each narrowband channel and the probabilities of that the PUs are located respectively at each neighboring beam under the condition of the PUs located at the given beam and the given narrowband channel. To maximize the spectrum utility, we propose to model the spectrum leasing market of the cognitive network for the obtained opportunities in the framework of the differential games, such that the spectrum price and demand are controlled by a dynamic system. We then derive the open-loop equilibria of the game. Simulation results confirm the efficacy of the proposed methods.