Sum Rate Maximization for Movable Antenna Enabled Uplink NOMA

TL;DR

This paper explores how movable antennas can be optimized in uplink NOMA systems to significantly improve sum rate performance by jointly optimizing antenna positions, decoding order, and power control.

Contribution

It introduces a novel joint optimization framework for movable antennas in uplink NOMA, including a tractable solution approach for the non-convex problem.

Findings

Movable antennas significantly outperform fixed-position antennas in sum rate.

The proposed optimization method effectively enhances system performance.

Movable antenna NOMA surpasses orthogonal multiple access in sum rate.

Abstract

Movable antenna (MA) has been recently proposed as a promising candidate technology for the next generation wireless communication systems due to its significant capability of reconfiguring wireless channels via antenna movement. In this letter, we study an MA-enabled uplink non-orthogonal multiple access (NOMA) system, where each user is equipped with a single MA. Our objective is to maximize the users' sum rate by jointly optimizing the MAs' positions, the decoding order and the power control. To solve this non-convex problem, we equivalently transform it into two tractable subproblems. First, we use the successive convex approximation (SCA) to find a locally optimal solution for the antenna position optimization subproblem. Next, we derive the closed-form optimal solution of the decoding order and power control subproblem. Numerical results show that our proposed MA-enabled NOMA system can significantly enhance the sum rate compared to fixed-position antenna (FPA) systems and orthogonal multiple access (OMA) systems.