  This paper studies the resource allocation problem for a heterogeneous
network (HetNet) in which the spectrum owned by a macro-cell operator (MCO) can
be shared by both unlicensed users (UUs) and licensed users (LUs). We formulate
a novel hierarchical game theoretic framework to jointly optimize the transmit
powers and sub-band allocations of the UUs as well as the pricing strategies of
the MCO. In our framework, an overlapping coalition formation (OCF) game has
been introduced to model the cooperative behaviors of the UUs. We then
integrate this OCF game into a Stackelberg game-based hierarchical framework.
We prove that the core of our proposed OCF game is non-empty and introduce an
optimal sub-band allocation scheme for UUs. A simple distributed algorithm is
proposed for UUs to autonomously form optimal coalition formation structure.
The Stackelberg Equilibrium (SE) of the proposed hierarchical game is derived
and its uniqueness and optimality have been proved. A distributed joint
optimization algorithm is also proposed to approach the SE of the game with
limited information exchanges between the MCO and the UU.
