A Study on D2D Communication Based on NOMA Technology

Considering the spectrum utilization of cellular system and the overall communication capacity of the system, a device-to-device (D2D) communication system model which based on non-orthogonal multiple access technology (NOMA) is established, and the concept of “D2D group” which allows one D2D transmitter communicate with multiple D2D receivers simultaneously is introduced. In this model, D2D groups utilize NOMA technology for transmission, and multiple D2D groups can reuse the same sub-channel. Aimed at the co-channel interference caused by shared spectrum resources between cellular users and D2D groups, and the power allocation problem based on the NOMA principle in the D2D groups, an optimization problem of maximum the total rate of cellular networks is handled by two steps. Firstly, an effective resource allocation scheme based on weighted bipartite graph algorithm is proposed and then obtains the power allocation scheme of each D2D group by converting the power allocation factor into an unknown quantity. The simulation results show that the algorithm which is proposed can greatly increase the number of D2D user groups and the total speed of cellular system.