Multi-user Grouping Algorithm in Multi-carrier NOMA System

Nonorthogonal multiple access technique enables multiple terminals to access the network at the same time and frequency, which improves the number of connection and the spectrum efficiency. User grouping and power allocation for multiple terminals are unsolved problems in a multi-carrier communication network. A network topology construction method and a length-constrained minimum path cover algorithm are proposed to solve the user grouping problem. The simulation results show that the proposed methods can maximize the number of network connection and have higher spectrum efficiency than the traditional two-user pairing scheme.