Sum-Rate Maximization for Movable-Antenna Array Enhanced Downlink NOMA Systems

Fuente: arXiv
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Main Authors: Li, Nianzu, Wu, Peiran, Zhu, Lipeng, Mei, Weidong, Ning, Boyu, Ng, Derrick Wing Kwan
Format: Preprint
Published: 2025
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author Li, Nianzu
Wu, Peiran
Zhu, Lipeng
Mei, Weidong
Ning, Boyu
Ng, Derrick Wing Kwan
author_facet Li, Nianzu
Wu, Peiran
Zhu, Lipeng
Mei, Weidong
Ning, Boyu
Ng, Derrick Wing Kwan
contents Movable antenna (MA) systems have recently attracted significant attention in the field of wireless communications owing to their exceptional capability to proactively reconfigure wireless channels via flexible antenna movements. In this paper, we investigate the resource allocation design for an MA array-enhanced downlink non-orthogonal multiple access (NOMA) system, where a base station deploys multiple MAs to serve multiple single-antenna users. Our goal is to maximize the sum rate of all users by jointly optimizing the transmit beamforming, positions of MAs, successive interference cancellation (SIC) decoding order, and users' corresponding decoding indicator matrix, while adhering to constraints on the maximum transmit power and finite MA moving region. The formulated problem is inherently highly non-convex, rendering it challenging to acquire a globally optimal solution. As a compromise, we propose a low-complexity two-stage optimization algorithm to obtain an effective suboptimal solution. Specifically, in stage one, the SIC decoding order is first determined by solving a channel gain maximization problem. Then, in stage two, with the given SIC decoding order, the beamforming vectors, MA positions, and users' decoding indicator matrix are iteratively optimized by capitalizing on alternating optimization, successive convex approximation (SCA), and genetic algorithm (GA). Simulation results unveil that the sum-rate performance of the proposed MA-enabled downlink NOMA system significantly outperforms that of conventional fixed-position antenna (FPA) systems. Moreover, the results also show that the antenna position optimization in the proposed algorithm can further enhance the advantages of NOMA over space division multiple access (SDMA).
format Preprint
id arxiv_https___arxiv_org_abs_2507_15555
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Sum-Rate Maximization for Movable-Antenna Array Enhanced Downlink NOMA Systems
Li, Nianzu
Wu, Peiran
Zhu, Lipeng
Mei, Weidong
Ning, Boyu
Ng, Derrick Wing Kwan
Signal Processing
Movable antenna (MA) systems have recently attracted significant attention in the field of wireless communications owing to their exceptional capability to proactively reconfigure wireless channels via flexible antenna movements. In this paper, we investigate the resource allocation design for an MA array-enhanced downlink non-orthogonal multiple access (NOMA) system, where a base station deploys multiple MAs to serve multiple single-antenna users. Our goal is to maximize the sum rate of all users by jointly optimizing the transmit beamforming, positions of MAs, successive interference cancellation (SIC) decoding order, and users' corresponding decoding indicator matrix, while adhering to constraints on the maximum transmit power and finite MA moving region. The formulated problem is inherently highly non-convex, rendering it challenging to acquire a globally optimal solution. As a compromise, we propose a low-complexity two-stage optimization algorithm to obtain an effective suboptimal solution. Specifically, in stage one, the SIC decoding order is first determined by solving a channel gain maximization problem. Then, in stage two, with the given SIC decoding order, the beamforming vectors, MA positions, and users' decoding indicator matrix are iteratively optimized by capitalizing on alternating optimization, successive convex approximation (SCA), and genetic algorithm (GA). Simulation results unveil that the sum-rate performance of the proposed MA-enabled downlink NOMA system significantly outperforms that of conventional fixed-position antenna (FPA) systems. Moreover, the results also show that the antenna position optimization in the proposed algorithm can further enhance the advantages of NOMA over space division multiple access (SDMA).
title Sum-Rate Maximization for Movable-Antenna Array Enhanced Downlink NOMA Systems
topic Signal Processing
url https://arxiv.org/abs/2507.15555