Joint user grouping and power allocation in VLC-NOMA system
Joint user grouping and power allocation in VLC-NOMA system
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DOI：
10.1016/j.phycom.2022.101841
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发表时间：
2022-08
期刊：
影响因子：
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通讯作者：
Huanlin Liu;Bingchuan Huang;Jian Yang;Yong Chen;Tong Zhang;Shuai Yang;Ke Chen
中科院分区：
文献类型：
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作者：
Huanlin Liu;Bingchuan Huang;Jian Yang;Yong Chen;Tong Zhang;Shuai Yang;Ke Chen
随着无线网络能耗的不断增加，可见光通信（VLC）被认为是一种有前途的实现节能的技术。由于海量的终端接入和不断增加的流量需求，在VLC网络中实施非正交多址（NOMA）技术已成为必然趋势。在本文中，我们的目标是最大限度地提高 VLC-NOMA 网络的能源效率。假设完全了解用户设备的信道状态信息，能量效率最大化问题被表述为混合整数非线性规划问题。为了解决这个问题，提出了联合用户分组和功率分配(JUGPA)，包括用户分组和功率分配。在用户分组阶段，我们利用所有用户设备之间信道增益的平均值，提出了一种低复杂度的动态用户分组算法。所提出的方案利用用户之间的信道增益差异并将其分为多个组。在功率分配阶段，我们提出了一种功率分配算法，用于最大化给定 NOMA 组的能源效率。由于目标函数是分数形式且非凸的，我们首先将其转换为差分形式和凸函数。然后，我们通过丁克尔巴赫方法和拉格朗日对偶分解方法推导了使能源效率最大化的封闭式最优功率分配表达式。仿真结果表明，JUGPA能够有效提高VLC-NOMA网络的能源效率。
With the energy consumption of wireless networks increasing, visible light communication (VLC) has been regarded as a promising technology to realize energy conservation. Due to the massive terminals access and increased traffic demand, the implementation of non-orthogonal multiple access (NOMA) technology in VLC networks has become an inevitable trend. In this paper, we aim to maximize the energy efficiency in VLC-NOMA networks. Assuming perfect knowledge of the channel state information of user equipment, the energy efficiency maximization problem is formulated as a mixed integer nonlinear programming problem. To solve this problem, the joint user grouping and power allocation (JUGPA) is proposed including user grouping and power allocation. In user grouping phase, we utilize the average of channel gain among all user equipment and propose a dynamic user grouping algorithm with low complexity. The proposed scheme exploits the channel gain differences among users and divides them into multiple groups. In power allocation phase, we proposed a power allocation algorithm for maximizing the energy efficiency for a given NOMA group. Thanks to the objective function is fraction form and non-convex, we firstly transform it to difference form and convex function. Then, we derive the closed-form optimal power allocation expression that maximizes the energy efficiency by Dinkelbach method and Lagrange dual decomposition method. Simulation results show that the JUGPA can effectively improve energy efficiency of the VLC-NOMA networks.