Interference Hypergraph-Based 3D Matching Resource Allocation Protocol for NOMA-V2X Networks

Vehicle-to-everything (V2X) communications are regarded as the key technology in future vehicular networks due to its ability in providing efficient and reliable massive connections, improving traffic efficiency and safety, and supporting in-vehicle entertainment and working. Recently, non-orthogonal multiple access (NOMA), as a promising solution in the fifth-generation (5G) mobile communication systems, has drawn much attention because it can significantly improve the network throughput and lower the accessing and transmission latency to meet the quality-of-service (QoS) requirements of many 5G-enabled applications. Noticing these, in this paper, we consider a device-to-device (D2D)-enhanced V2X network, in which NOMA is introduced to increase the capacity. In our studied NOMA-V2X system, except for the NOMA-based intra-group resource reuse, the D2D-enabled resource sharing based on spatial reuse among all the V2X communication groups is also permitted through centralized resource management, leading to a significantly improved network performance but a more complicated and challenging interference scenario. In order to efficiently manage the interference and allocate the resource in the NOMA-V2X network, we create a weighted 3-partite interference hypergraph (IHG) to imitate the complex interference environment in our studied scenario. Then, with the help of this hypergraph, we make another step to put forward an IHG-based 3-dimensional matching (IHG-3DM) resource allocation protocol with a greedy 3DM algorithm and an iterative 3DM algorithm. As a consequence, the network throughput is significantly improved with the help of our proposed IHG-3DM resource allocation protocol for the investigated NOMA-integrated V2X communications, which is verified by the simulation results.