Efficient power allocation for downlink MIMO-NOMA-based visible light communication systems

Abstract

Visible light communication (VLC) networks are emerging as a viable option to meet the ever-growing wireless data demand, primarily for indoor environments in recent years. However, developing a high data rate VLC system using off-the-shelf light emitting diodes (LEDs) is difficult due to the narrow modulation bandwidth of the white light emitting diodes. The existing studies have integrated Multiple-Input Multiple-Output (MIMO) and Non-Orthogonal Multiple Access (NOMA) schemes into the downlink VLC system so as improve its performance. Despite its apparent advantages, the NOMA scheme suffers from multi-user interference problem. For an efficient NOMA scheme, which uses successive interference cancellation (SIC) technique to decode the superimposed received signal of multipleusers, adaptive and fair power allocation methods are required. The existing power allocation schemes are inefficient when the number of users increases. In this work, a low complexity and efficient power allocation strategy is proposed for MIMO-NOMA based VLC systems. The proposed parametric power allocation strategy is based on the order of channel gain among end-users and overcomes the limitations of the existing schemes. The performance of the proposed power allocation scheme in an indoor 4$\times$4 MIMO-NOMA-based multi-user VLC was analyzed through simulation. A zero-forcing detection mechanism is used in the analysis. Simulation results using MATLAB depict the effectiveness of the proposed power allocation strategy. It achieves higher performance than the existing power allocation schemes, gain ratio power allocation (GRPA) and normalized gain difference power allocation (NGDPA) when the number of users are greater than two. Specifically, the proposed power allocation scheme improves the achievable sum rate of the NGDPA and GRPA schemes by 18.36% and 65.98%, respectively, in 4$\times$ 4 MIMO-based visible light communication networks with eight uniformly distributed users.

Keywords:

• Non-Orthogonal multiple accesses
• multiple input multiple output
• visible light communication
• MIMO
• NOMA

Reviewing Editor:

• Qingsong Ai; Wuhan University of Technology; China

Subjects:

• Communications & Information Processing
• Electrical Engineering Communications
• Radio
• Satellites
• Television & Audio
• Telecommunication

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors did not receive support from any organization for the submitted work.

Notes on contributors

Gemechu Tesfaye Tola

Gemechu Tesfaye Tola received BSc. degree in Electrical and Computer Engineering from Jimma University, Jimma, Ethiopia in 2017, the MSc. degree in Communication Engineering from Jimma University, Jimma, Ethiopia, in 2021. Since then he is working in the department of Electrical and Computer Engineering, Salale University, Ethiopia. His research interests include Visible Light Communication, Wireless Communication and Antenna Designing.

Kinde Anlay Fante

Kinde Anlay Fante received the B.Sc. degree in electrical engineering from Bahir Dar University, Bahir Dar, Ethiopia, in 2008, the M.Tech. degree in electronics and computer engineering from Addis Ababa University, Ethiopia, in 2010, and the Ph.D. degree in electrical engineering from Indian Institute of Technology Delhi, India, in 2016. Since 2016, he has been working in the Faculty of Electrical and Computer Engineering, Jimma Institute of Technology, Jimma University, Ethiopia. His research interests include VLSI design for image and video processing, digital signal processing, antenna design, wireless communication, and machine learning.

Sherwin Nogueras Catolos

Sherwin Nogueras Catolos received the B.Sc. Degree in Electronics and Communications Engineering at Cagayan State University, Carig Campus, Tuguegarao, Philippines in 2001, the Masters of Engineering degree Major in ECE at University of Saint Louis (USL) Tuguegarao in 2008, and he is currently pursuing Ph.D. degree in Engineering Management at University of Saint Louis Tuguegarao (2022). He started working with the School of Engineering, Architecture and Information Technology Education (SEAIT E) as a faculty at USLTuguegarao Philippines since 2001. He also worked as an Electronics engineer at ESCO Micro, P T E, LTd based in Singapore in 2009. He also joined the group of expatriates to teach at Jimma Institute of Technology, Jimma University, Ethiopia from 2012-2021. His research interests include antenna design, digital signal processing, and in wire and wireless communication.