  The small cells in millimeter wave (mmWave) have been utilized extensively
for the fifth generation (5G) mobile networks. And full-duplex (FD)
communications become possible with the development of self-interference (SI)
cancellation technology. In this paper, we focus on the optimal allocation of
the sub-channels in the small cells deployed densely underlying the mmWave
networks. In order to improve the resource utilization and network capacity,
device-to-device (D2D) communications are adopted in networks. For maximizing
the system throughput, we propose a cooperative sub-channel allocation approach
based on coalition formation game, and theoretically prove the convergence of
the proposed allocation algorithm. The utility of the coalition formation game
is closely related to the sum system throughput in this paper, and each link
makes an individual decision to leave or join any coalition based on the
principle of maximizing the utility. Besides, a threshold of the minimum
transmission rate is given to improve the system fairness. Through extensive
simulations, we demonstrate that our proposed scheme has a near-optimal
performance on sum throughput. In addition, we verify the low complexity of the
proposed scheme by simulating the number of switch operations.
