Resource Exchange in Smart Grid Connected Cooperative Cognitive Radio Networks

Wireless telecommunications is experiencing a massive penetration of wireless devices and an exponential growth in wireless applications. To accommodate the expected service requirements with the available radio resources, we present a new radio resource exchange scheme for a smart grid connected cognitive radio system, in which independently harvested energy can be stored in the smart grid in the form of on-grid credit. The secondary system will gain spectrum usage by either forwarding primary data or transferring energy credit directly to the primary system. In particular, to maximize the overall energy saving while meeting the throughput requirement, the utilities of both systems are optimized by jointly designing the subchannel assignment scheme with power control. First, for any given subchannel assignment, we have derived the optimal power allocated by both primary and secondary systems to each subchannel. Then, the characteristics of the subchannel assignment scheme are analyzed, and the complexity of finding the optimal assignment is reduced. Finally, a novel joint subchannel assignment and power control scheme is proposed to decide whether and how to cooperate by comparing the utilities of both systems with and without cooperation. Simulations results are presented to verify the optimality of the derived scheme.