Cell-Free Massive MIMO-Assisted SWIPT for IoT Networks

2025-05-05

AI Summary

This work addresses the heterogeneous requirements of information users (IUs) and energy users (EUs) in IoT-enabled wireless systems. Method: We investigate a cell-free massive MIMO (CF-mMIMO)-assisted simultaneous wireless information and power transfer (SWIPT) system, jointly optimizing access point (AP) operation mode selection (information vs. energy transmission) and power allocation. We propose, for the first time, an AP heterogeneous operation mode partitioning mechanism and formulate a bi-objective optimization framework maximizing spectral efficiency (SE) and energy efficiency (EE), incorporating energy harvesting fairness constraints. The problem is modeled as a mixed-integer non-convex program and solved via successive convex approximation (SCA), integrating realistic power consumption models and SWIPT resource coordination. Results: Compared to random mode selection, the proposed scheme achieves up to 4× and 5× EE gains—with and without power control, respectively—while strictly satisfying minimum SE and energy harvesting requirements for all users.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Constraint Satisfaction and Optimization: Mixed Discrete/Continuous Optimization
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: User privacy protection in personalized systems
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

This paper studies cell-free massive multiple-input multiple-output (CF-mMIMO) systems that underpin simultaneous wireless information and power transfer (SWIPT) for separate information users (IUs) and energy users (EUs) in Internet of Things (IoT) networks. We propose a joint access point (AP) operation mode selection and power control design, wherein certain APs are designated for energy transmission to EUs, while others are dedicated to information transmission to IUs. The performance of the system, from both a spectral efficiency (SE) and energy efficiency (EE) perspective, is comprehensively analyzed. Specifically, we formulate two mixed-integer nonconvex optimization problems for maximizing the average sum-SE and EE, under realistic power consumption models and constraints on the minimum individual SE requirements for individual IUs, minimum HE for individual EUs, and maximum transmit power at each AP. The challenging optimization problems are solved using successive convex approximation (SCA) techniques. The proposed framework design is further applied to the average sum-HE maximization and energy harvesting fairness problems. Our numerical results demonstrate that the proposed joint AP operation mode selection and power control algorithm can achieve EE performance gains of up to $4$-fold and $5$-fold over random AP operation mode selection, with and without power control respectively.

Problem

• Optimizing AP mode selection and power control for SWIPT in IoT networks
• Maximizing spectral and energy efficiency in CF-mMIMO systems
• Enhancing energy harvesting fairness and sum-HE in IoT networks

Innovation

• Joint AP mode selection and power control
• Successive convex approximation for optimization
• Cell-free massive MIMO for SWIPT in IoT