Flexible Precoding for Multi-User Movable Antenna Communications (2402.18847v1)
Abstract: This letter rethinks traditional precoding in multi-user wireless communications with movable antennas (MAs). Utilizing MAs for optimal antenna positioning, we introduce a sparse optimization (SO)-based approach focusing on regularized zero-forcing (RZF). This framework targets the optimization of antenna positions and the precoding matrix to minimize inter-user interference and transmit power. We propose an off-grid regularized least squares-based orthogonal matching pursuit (RLS-OMP) method for this purpose. Moreover, we provide deeper insights into antenna position optimization using RLS-OMP, viewed from a subspace projection angle. Overall, our proposed flexible precoding scheme demonstrates a sum rate that exceeds more than twice that of fixed antenna positions.
- R. He, B. Ai, G. Wang, M. Yang, C. Huang, and Z. Zhong, “Wireless channel sparsity: Measurement, analysis, and exploitation in estimation,” IEEE Wireless Communications, vol. 28, no. 4, pp. 113–119, 2021.
- S. Yang, C. Xie, D. Wang, and Z. Zhang, “Fast multibeam training for mmwave mimo systems with subconnected hybrid beamforming architecture,” IEEE Systems Journal, vol. 17, no. 2, pp. 2939–2949, 2023.
- C. Huang, A. Zappone, G. C. Alexandropoulos, M. Debbah, and C. Yuen, “Reconfigurable intelligent surfaces for energy efficiency in wireless communication,” IEEE Transactions on Wireless Communications, vol. 18, no. 8, pp. 4157–4170, 2019.
- Q. Wu and R. Zhang, “Intelligent reflecting surface enhanced wireless network via joint active and passive beamforming,” IEEE Transactions on Wireless Communications, vol. 18, no. 11, pp. 5394–5409, 2019.
- H. Lu and Y. Zeng, “Near-field modeling and performance analysis for multi-user extremely large-scale mimo communication,” IEEE Communications Letters, vol. 26, no. 2, pp. 277–281, 2022.
- S. Yang, W. Lyu, Z. Hu, Z. Zhang, and C. Yuen, “Channel estimation for near-field xl-ris-aided mmwave hybrid beamforming architectures,” IEEE Transactions on Vehicular Technology, vol. 72, no. 8, pp. 11 029–11 034, 2023.
- L. Zhu, W. Ma, and R. Zhang, “Movable antennas for wireless communication: Opportunities and challenges,” IEEE Communications Magazine, pp. 1–7, 2023.
- K. K. Wong, A. Shojaeifard, K.-F. Tong, and Y. Zhang, “Performance limits of fluid antenna systems,” IEEE Communications Letters, vol. 24, no. 11, pp. 2469–2472, 2020.
- M. Gharavi-Alkhansari and A. Gershman, “Fast antenna subset selection in mimo systems,” IEEE Transactions on Signal Processing, vol. 52, no. 2, pp. 339–347, 2004.
- B. Fuchs, “Synthesis of sparse arrays with focused or shaped beampattern via sequential convex optimizations,” IEEE Transactions on Antennas and Propagation, vol. 60, no. 7, pp. 3499–3503, 2012.
- S. Yang, B. Liu, Z. Hong, and Z. Zhang, “Low-complexity sparse array synthesis based on off-grid compressive sensing,” IEEE Antennas and Wireless Propagation Letters, vol. 21, no. 12, pp. 2322–2326, 2022.
- K.-K. Wong and K.-F. Tong, “Fluid antenna multiple access,” IEEE Transactions on Wireless Communications, vol. 21, no. 7, pp. 4801–4815, 2022.
- H. Qin, W. Chen, Z. Li, Q. Wu, N. Cheng, and F. Chen, “Antenna Positioning and Beamforming Design for Fluid-Antenna Enabled Multi-user Downlink Communications,” arXiv e-prints, p. arXiv:2311.03046, Nov. 2023.
- L. Zhu, W. Ma, and R. Zhang, “Modeling and performance analysis for movable antenna enabled wireless communications,” IEEE Transactions on Wireless Communications, pp. 1–1, 2023.
- L. Zhu, W. Ma, B. Ning, and R. Zhang, “Movable-antenna enhanced multiuser communication via antenna position optimization,” IEEE Transactions on Wireless Communications, pp. 1–1, 2023.
- X. Pi, L. Zhu, Z. Xiao, and R. Zhang, “Multiuser Communications with Movable-Antenna Base Station Via Antenna Position Optimization,” arXiv e-prints, p. arXiv:2308.05546, Aug. 2023.
- X. Lai, T. Wu, J. Yao, C. Pan, M. Elkashlan, and K.-K. Wong, “On performance of fluid antenna system using maximum ratio combining,” IEEE Communications Letters, vol. 28, no. 2, pp. 402–406, 2024.