Non-orthogonal multiple access (NOMA) is one of the various techniques that attracted extensive attention due to its superior spectrum efficiency. In this paper, joint access and backhaul resource allocation in a 5G Heterogeneous ultra-dense network (H-UDN) are proposed in order to maximize the overall system throughput. We adopt a decouple method to separate the joint resource problem into two subproblems. The user-channel assignment subproblem is solved via a matching scheme and the power allocation subproblem is solved via a Stackelberg game, in which the base station (BS) acts as the leader and the relay node (RN) acts as a follower. Simulation results show the effectiveness of our approach.