Cooperative Spectrum Leasing to Femtocells with Interference Compensation

Spectrum leasing is a novel promising technique to improve the spectrum efficiency (SE) through the spectrum owner leasing its free or under-utilization spectrum to unlicensed users for superfluous spectrum revenue, while the unlicensed users should pay for spectrum renting. Recently, spectrum leasing is used between femtocell service provider (FSP) and the coexisting macrocell service provider (MSP) in heterogeneous networks (HetNets). However, the energy efficiency (EE), a critical performance metric in HetNets, especially when multiple FSPs are densely overlaid on the coverage of MSP, has been largely neglected in available SE-oriented spectrum leasing. In this paper, a cooperative spectrum leasing framework is proposed to both mitigate interference and save energy, where a Stackelberg coordination game is formulated to analyze a joint spectrum leasing, pricing and interference coordination process between FSPs and MSP with the novel energy-aware utility functions for the players of FSPs and MSP. We rigorously derive the optimal closed-form solutions of spectrum leasing, pricing, and power coordination solutions for the FSP and the MSP. We propose a multi-stage distributed algorithm to approach these solutions. Finally, simulation results are provided to clarify effects of multiple parameters in the gaming process and verify the final improved performance.