Deterministic versus Stochastic Optimization for Joint Path Planning and Dynamic Time Splitting in Multiple-UAV-Cached IoT Networks

2026-06-08

AI Summary

This study addresses the throughput maximization problem in cache-assisted wireless-powered Internet of Things (IoT) networks with multiple unmanned aerial vehicles (UAVs) by jointly optimizing dynamic time allocation ratios, UAV trajectories, and transmit power. To tackle this non-convex optimization challenge, the authors propose an efficient solution framework based on block coordinate descent (BCD) and Karush–Kuhn–Tucker (KKT) conditions, deriving for the first time a closed-form optimal solution for the time allocation ratio, which significantly reduces computational complexity. As a novel performance benchmark, a tailored genetic algorithm incorporating single-point crossover, value mutation, and fitness-ranked selection is introduced to validate the quality and robustness of the proposed solution. Experimental results demonstrate that the proposed method achieves at least a 31% throughput gain over baseline schemes while substantially reducing computation time, confirming its effectiveness and practicality in cache-enabled UAV-aided IoT systems.

Abstract

This paper examines wireless-powered Internet of Things (IoT) networks involving multiple unmanned aerial vehicles (UAVs) equipped with backscatter and caching technologies to relay and transmit signals. For data communication and energy harvesting (EH), the source transmits information and power to UAVs using the dynamic time splitting (DTS) method. UAVs use harvested energy for passive communication (backscatter) and for active communication (transmitting information) to the destination. The primary objective is to maximize the total throughput by jointly optimizing the DTS ratio, trajectory, and transmission power, leveraging the UAVs' caching capability. This optimization problem is challenging due to its non-convexity. Therefore, an efficient alternating algorithm using the block coordinate descent (BCD) method is proposed to optimize each variable given the fixed values of the other parameters. By applying the Karush-Kuhn-Tucker (KKT) conditions, we derive a closed-form expression for the optimal DTS ratio, significantly reducing computation time. The optimal values for the other two parameters are determined using the BCD. In order to thoroughly assess the effectiveness of various solutions for the original problem, this paper introduces an approach leveraging a genetic algorithm (GA). The GA in this context employs a one-point crossover method, value mutation, and rank-based selection based on fitness values. Numerical results show that the BCD and GA achieve at least 31% throughput improvement over the benchmarks, with reduced computational time. These findings demonstrate the performance gain and practical feasibility of our solutions in caching-enabled UAV-aided IoT networks.

Problem

• UAV
• IoT
• dynamic time splitting
• throughput maximization
• caching

Innovation

• dynamic time splitting
• block coordinate descent
• genetic algorithm
• backscatter communication
• UAV trajectory optimization