  In this paper, a novel joint design of beamforming and power allocation is
proposed for a multi-cell multiuser multiple-input multiple-output (MIMO)
non-orthogonal multiple access (NOMA) network. In this network, base stations
(BSs) adopt coordinated multipoint (CoMP) for downlink transmission. We study a
new scenario where the users are divided into two groups according to their
quality-of-service (QoS) requirements, rather than their channel qualities as
investigated in the literature. Our proposed joint design aims to maximize the
sum-rate of the users in one group with the best-effort while guaranteeing the
minimum required target rates of the users in the other group. The joint design
is formulated as a non-convex NP-hard problem. To make the problem tractable, a
series of transformations are adopted to simplify the design problem. Then, an
iterative suboptimal resource allocation algorithm based on successive convex
approximation is proposed. In each iteration, a rank-constrained optimization
problem is solved optimally via semidefinite program relaxation. Numerical
results reveal that the proposed scheme offers significant sum-rate gains
compared to the existing schemes and converges fast to a suboptimal solution.
