Recent advances in communication technology have demonstrated the feasibility of full-duplex communication for a node to simultaneously transmit and receive on the same frequency band. Although the full-duplex technique has the potential to double the capacity of point-to-point wireless links, the resource allocation in multi-user environment becomes more complicated due to user-dependent channel conditions and peruser power constraints. In this paper, we formulate the joint problem of subcarrier assignment and power allocation in full-duplex OFDMA networks, and develop an iterative solution based on the necessary condition for optimality. We evaluate our solution through extensive simulations, which shows that it empirically achieves near-optimal performance and outperforms other resource allocation schemes designed for half-duplex networks.