Resource Allocation for CoMP-NOMA Transmission in Ultra Dense Networks

Aiming at the problems of insufficient spectrum resources and severe inter-network interference in ultra-dense cellular networks, a collaborative multipoint transmission scheme based on the non-orthogonal multiple access technique is proposed. The optimization problem in ultra-dense networks is formulated as a mixed integer nonlinear programming (MINLP) problem, which is divided into two subproblems. The base station clustering subproblem first applies the K-Means algorithm for base station clustering, then introduces the adaptive user pairing (A-UP) algorithm to The NOMA grouping is determined, the particle swarm algorithm (PSO) is used to optimize the clustering results, and the power allocation subproblem is solved by a concave-convex process algorithm. Finally, a joint base station clustering and power allocation optimization scheme is proposed. The simulation results suggest that the scheme can successfully reduce the disruption between coordinated BSs and enhance the system and rate and spectrum utilization efficiency in the case of high user density.