Joint user association, subchannel assignment, and power allocation in full-duplex OFDMA heterogeneous networks

In-band full-duplex (FD) radio is regarded as a promising solution to enhance the spectral efficiency in the next-generation wireless networks. In this paper, the problem of joint user association, subchannel assignment, and power allocation in FD orthogonal frequency-division multiple access heterogeneous networks is considered. The weighted downlink and uplink sum rate of the network is maximized in a way that the transmit power of base stations and users remains below a given level. The problem is formulated as a nonconvex mixed-integer nonlinear programming optimization problem. Then, it is converted into a suboptimal problem, which can be solved iteratively using difference of convex programming algorithm. Numerical results show that the proposed iterative algorithm converges quickly in few numbers of iterations with different initialization points. The results also show that the sum rate of an FD heterogeneous network can be as much as 66 % higher than the sum rate of a half-duplex network.