Joint Resource Allocation in NOMA Systems with Imperfect SIC

In this paper, we study the joint resource allocation and the corresponding performance of non- orthogonal multiple access (NOMA) systems with imperfect successive interference cancellation (SIC), wherein we consider the precoding, user clustering and power allocation design in a single cell with one base station and multiple users. Specifically, we propose a precoding scheme based on zero-forcing beamforming, and a user clustering algorithm based on channel correlation to reduce inter-cluster interference. In order to maximize the sum capacity, the power allocation optimization problem is formulated and solved via interior point methods. Numerical and simulation results demonstrate that our proposed design has better sum capacity performance when SIC is imperfect.