Achieving primary secrecy in energy harvesting CRNs using stackelberg game

Physical layer security is a critical issue in cognitive radio networks (CRNs). This paper thus focuses on the joint primary user (PU) secrecy rate maximization and secondary user (SU) transmission capacity optimization problem in overlay CRNs. The PU leases its partial transmission spectrum to the SU for cooperative relaying opportunity by the SU. Different from previous works, the SU transmitter is energy constrained and can harvest energy from the environment. Both the PU and SU are selfish which means they only concentrate on their own performance. Given energy harvesting rate, we study the communication between PU and SU using Stackelberg game. A unique Nash Equilibrium point is achieved through mathematical analysis. Then we derive a distributed algorithm to jointly schedule the PU and SU behaviors in the network system. Both analytical result and simulation result demonstrate that both of PU network and SU network can achieve their optimal utilities.