  In this paper, we develop an energy efficient resource allocation scheme for
orthogonal frequency division multiple access (OFDMA) networks with in-band
full-duplex (IBFD) communication between the base station and user equipments
(UEs) considering a realistic self-interference (SI) model. Our primary aim is
to maximize the system energy efficiency (EE) through a joint power control and
sub-carrier assignment in both the downlink (DL) and uplink (UL), where the
quality of service requirements of the UEs in DL and UL are guaranteed. The
formulated problem is non-convex due to the non-linear fractional objective
function and the non-convex feasible set which is generally intractable. In
order to handle this difficulty, we first use fractional programming to
transform the fractional objective function to the subtractive form. Then, by
employing Dinkelbach method, we propose an iterative algorithm in which an
inner problem is solved in each iteration. Applying majorization-minimization
approximation, we make the inner problem convex. Also, by introducing a penalty
function to handle integer sub-carrier assignment variables, we propose an
iterative algorithm for addressing the inner problem. We show that our proposed
algorithm converges to the locally optimal solution which is also demonstrated
by our simulation results. In addition, simulation results show that by
applying the IBFD capability in OFDMA networks with efficient SI cancellation
techniques, our proposed resource allocation algorithm attains a 75% increase
in the EE as compared to the half-duplex system.
