Average Rate Analysis of Cooperative NOMA Aided Underwater Optical Wireless Systems

IEEE Open Journal of the Communications Society

Kapila W. S. Palitharathna¹  Roshan I. Godaliyadda²  Himal A. Suraweera²  Vijitha R. Herath²  John S. Thompson³ 

[1] Centre for Telecommunication Research, School of Engineering, Sri Lanka Technological Campus, Padukka, Sri Lanka;Department of Electrical and Electronic Engineering, University of Peradeniya, Peradeniya, Sri Lanka;School of Engineering, Institute for Digital Communications, The University of Edinburgh, Edinburgh, U.K.;

关键词: Underwater optical wireless communication;    cooperative non-orthogonal multiple access (NOMA);    performance analysis;    lower bound;    achievable sum rate;    LED/PD selection;   

DOI  :  10.1109/OJCOMS.2021.3116146

来源: DOAJ

【 摘 要 】

In this paper, we consider a cooperative non-orthogonal multiple access (NOMA) aided underwater optical wireless system in which the source transmits to two users where the near user serves as a relay node to the far user. Our proposed system consists of multiple narrow-angle light-emitting diode (LED)/photodiode (PD) elements at the source, near user, and far user. In order to achieve communication, our system selects a single LED/PD at each node. We propose several low complexity LED/PD selection schemes that aim to maximize the link throughput and in addition consider optimal and random LED/PD selection for benchmarking. In order to characterize the performance of each scheme, bounds and closed-form tight approximations on the average achievable sum rates are presented. The use of multi element nodes and NOMA increase the average sum rate significantly over conventional orthogonal access. Moreover, near-optimal throughput can be achieved using channel gain based and line-of-sight based LED/PD selection schemes in the medium-to-high transmit power regimes. The derived expressions are also useful to investigate the impact of key system and channel parameters such as the source transmit power, power allocation factor, node placement, and the number of elements at each node.

【 授权许可】

Unknown