Power Allocation of Non-Orthogonal Multiple Access Based on Dynamic User Priority for Indoor QoS-Guaranteed Visible Light Communication Networks

Siyu Tao,Hongyi Yu,Qing Li,Xiangwei Bai,Yanqun Tang

doi:10.3390/app8081219

Abstract

Non-orthogonal multiple access (NOMA) simultaneously provides multi-user access over the same frequency band or time period, which can significantly improve system throughput in visible light communication (VLC) networks. However, the different interference components of NOMA and the diversified user requirements in VLC are difficult to coordinate. To guarantee both throughput enhancement and quality of service (QoS) satisfaction, this paper presents a power allocation scheme based on dynamic user priority in indoor NOMA-VLC networks. We introduce fuzzy logic (FL) to flexibly analyse user priority and assign signal power using multi-dimensional user features. The experimental results show that our method achieves the best performance in terms of user fairness and satisfaction. In indoor VLC, which has small cells with a high user density, our method outperforms contrastive schemes in terms of the average user data rate (AUDR). Therefore, in comparisons between static and dynamic user priority, our study indicates the fairness advantages of FL for the dynamic evaluation of user priority. In comparisons between NOMA and orthogonal multiple access, our study reflects the AUDR advantages of non-orthogonal methods. Furthermore, in comparisons of user satisfaction, our method outperforms existing methods, indicating the achievement of the QoS guarantee.

Highlights

The international telecommunications union-radio communications sector (ITU-R) has published the recommendations and key capabilities of next-generation wireless communication, in which the three-type high densities of users, the number of access points (APs) and the area traffic requirement are important performance indicators in the indoor ultra-dense network (UDN) scenario [1].For illuminations in architecture, optical sources are ubiquitous and the inter-site distance (ISD)of optical APs is much smaller than in traditional cellular or wireless local area networks
In regard to the tradeoff between the user data rate and fairness, this paper presents a quality of service (QoS)-guaranteed gain ratio power allocation (GRPA) based on fuzzy logic (FL) in indoor Non-orthogonal multiple access (NOMA)-visible light communication (VLC) networks
In the optical line of sight (LOS) path shown in Figure 1, the VLC channel gain for the indoor k-th user is assumed by (1), where φk is the angle of irradiation of the light-emitting diode (LED) lights, ψk is the angle of incidence, Φ1/2 is the semi-angle of the LED, A is the received area of a photo diode, γ is the optical-electrical conversion efficiency and T f is the gain of the optical filter: hk =

Summary

Introduction

The international telecommunications union-radio communications sector (ITU-R) has published the recommendations and key capabilities of next-generation wireless communication, in which the three-type high densities of users, the number of access points (APs) and the area traffic requirement are important performance indicators in the indoor ultra-dense network (UDN) scenario [1]. Of optical APs is much smaller than in traditional cellular or wireless local area networks. To deal with three-type densities, visible light communication (VLC) is a complementary networking scheme of optical wireless communication (OWC) to split cells and improve the spectrum reuse for dense indoor scenes [3]. For high AP density, the ISD of optical devices in the office or at home may be less than 10 metres.

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