Hybrid Beamforming for Nonlinear SWIPT in Terahertz Massive MIMO Systems

NONE 20260311110907739 wseas/wseas content-registration-form+ja@crossref.org content-registration-form WSEAS TRANSACTIONS ON POWER SYSTEMS 1790-5060 2224-350X Hybrid Beamforming for Nonlinear SWIPT in Terahertz Massive MIMO Systems Md. Asif Hossain Department of Electrical and Electronic Engineering Southeast University Tejgaon, Dhaka-1208, BANGLADESH Terahertz communications are one of the 6G technologies, offering very high data rates with an extremely large path loss and very short range, making it extremely challenging for energy-limited IoT devices. Simultaneous Wireless Information and Power Transfer (SWIPT) has emerged, but new designs employ an optimal linear energy-harvesting model that does not account for nonlinear rectifier operations. By contrast, we introduce a novel hybrid beamforming solution for wideband THz massive MIMO communications that incorporates a realistic nonlinear energy-harvesting model. We formulate an optimization problem to maximize a weighted sum of the rate and the total harvested energy, subject to transmit power constraints, constant-modulus constraints, and quality-of-service requirements. The derived nonconvex optimization problem can be efficiently addressed employing a two-stage solution. The first stage focuses on optimizing analog beamformers via shaping signals on the main Line-of-Sight components and addressing frequency-dependent beam squint effects. Digital precoders and coordinate-wise power splitting ratios will be jointly optimized with an efficient Successive Convex Approximation (SCA) method using Block Coordinate Descent (BCD). Simulation experiments demonstrate superior gains for the proposed solution compared with traditional designs that exploit optimal linear energy models, and these benefits will be more pronounced for near- and mid-field THz communications. Our work demonstrates an intrinsic trade-off in realistic THz communications and energy-limited IoT networking. These findings and challenges underscore the urgent need to model THz communications that consider RF circuit modules and to enable efficient, energy-saving 6G wireless networking for simultaneous wireless power and high-throughput communications. 12 31 2025 12 31 2025 456 36 https://creativecommons.org/licenses/by/4.0/deed.en_US 10.37394/232016.2025.20.36 https://wseas.com/journals/ps/2025/a725116-927.pdf W. Saad, M. Bennis, and M. Chen, “A Vision of 6G Wireless Systems: Applications, Trends, Technologies, and Open Research Problems,” IEEE Netw, vol. 34, no. 3, pp. 134–142, 2020, doi: 10.1109/MNET.001.1900287. W. M. Othman, A. A. Ateya, M. E. Nasr, A. Muthanna, M. ElAffendi, A. Koucheryavy, & A. A. 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