Department of Electrical & Computer Engineering, COMSATS University Islamabad, Wah Campus, Wah Cantonment 47040, Pakistan.
Department of Applied Science & Engineering, Thompson Rivers University (TRU), Kamloops, BC V2C 0C8, Canada.
Sensors (Basel). 2018 Oct 20;18(10):3560. doi: 10.3390/s18103560.
Cooperative communication with RF energy harvesting relays has emerged as a promising technique to improve the reliability, coverage, longevity and capacity of future IoT networks. An efficient relay assignment with proper power allocation and splitting is required to satisfy the network's QoS requirements. This work considers the resource management problem in decode and forward relay based cooperative IoT network. A realistic mathematical model is proposed for joint user admission, relay assignment, power allocation and splitting ratio selection problem. The optimization problem is a mixed integer non-linear problem (MINLP) whose objective is to maximize the overall sum rate (bps) while satisfying the practical network constraints. Further, an outer approximation algorithm is adopted which provides epsilon-optimal solution to the problem with guaranteed convergence and reasonable complexity. Simulations of the proposed solution are carried out for various network scenarios. The simulation results demonstrate that cooperative communication with diversity achieves a better admission of IoT users and increases not only their individual data rates but also the overall sum rate of an IoT network.
射频能量收集中继的协作通信已成为提高未来物联网网络可靠性、覆盖范围、寿命和容量的一种有前途的技术。需要有效的中继分配和适当的功率分配和分割来满足网络的 QoS 要求。本工作考虑基于解码和转发中继的协作物联网网络中的资源管理问题。针对联合用户准入、中继分配、功率分配和分割比选择问题,提出了一个现实的数学模型。优化问题是一个混合整数非线性问题 (MINLP),其目标是在满足实际网络约束的情况下最大化总和速率 (bps)。此外,采用外逼近算法为该问题提供ε最优解,具有保证收敛性和合理复杂度。针对各种网络场景对所提出的解决方案进行了仿真。仿真结果表明,具有分集功能的协作通信可以更好地接纳物联网用户,不仅提高了他们的个体数据速率,而且提高了物联网网络的总和速率。