Multi-cell cooperative transmission for MU-NOMA networks

In this paper, we consider the interference management for multi-cell scenarios. In order to effectively manage the inter-cell interference in multi-cell scenarios, a novel multi-cell cooperative grouping transmission scheme based on the power allocation and beam design for non-orthogonal multiple access (NOMA) multiuser multiple-input multiple-output (MU-MIMO) networks is proposed. In multi-cell scenarios, multiple base station cooperation is realized by using the coordinated multi-point (CoMP) transmission technology, and a novel CoMP-NOMA transmission model is established. For the interference management requirements, a novel multi-cell cooperative transmission scheme based on a grouping strategy is proposed to alleviate the limitations of the application scenarios of NOMA technology. For maximizing the sum rate (SR) of users in group1, the optimization problem of the power allocation and transmission beam is formulated. Considering the coupling relationship between the power allocation and transmission beam, a low complexity iterative algorithm combining the beam design and power allocation is proposed to solve the optimization problem and use fully space resources. Also, the convergence of the proposed algorithm is illustrated by the theoretical analysis. Simulation results show that the proposed scheme can effectively eliminate the inter-cell interference and improve the spectrum efficiency.