Distributed Power Allocation for Nonorthogonal Multiple Access Heterogeneous Networks

In this letter, we investigate the power allocation problem in nonorthogonal multiple access (NOMA) heterogeneous networks (HetNets), where the macrocell base station (MBS) and small cell base station (SBS) compete to maximize their own throughput with minimum rate requirement of each user. The throughput of MBS and SBS is formulated based on the equivalent channel gain, and the power allocation problem is captured as a Stackelberg game. A distributed power allocation algorithm is proposed to achieve the Stackelberg equilibrium. Simulation results demonstrate the convergence of the proposed algorithm. Meanwhile, it is verified that the combination of NOMA and HetNets possesses great potential to improve the spectrum efficiency compared to the orthogonal multiple access based HetNets.