Ultra-dense networks can further improve the spectrum efficiency (SE) and the energy
efficiency (EE). However, the interference avoidance and the green design are becoming
more complex due to the intrinsic densification and scalability. It is known that the much
denser small cells are deployed, the more cooperation opportunities exist among them. In
this paper, we characterize the cooperative behaviors in the Nash bargaining cooperative
game-theoretic framework, where we maximize the EE performance with a certain sacrifice …