Open Access

ARTICLE

Enhancements of SDR-Based FPGA System for V2X-VLC Communications

by Lukas Danys¹, Radek Martinek¹, Rene Jaros^1,*, Jan Baros¹, Petr Simonik², Vaclav Snasel³

1 Department of Cybernetics and Biomedical Engineering, Faculty of Electrical Engineering and Computer Science, VSB–Technical University of Ostrava, Ostrava-Poruba, 708 00, Czechia
2 Department of Electronics, Faculty of Electrical Engineering and Computer Science, VSB–Technical University of Ostrava, Ostrava-Poruba, 708 00, Czechia
3 Department of Computer Science, Faculty of Electrical Engineering and Computer Science, VSB–Technical University of Ostrava, Ostrava-Poruba, 708 00, Czechia

* Corresponding Author: Rene Jaros. Email:

Computers, Materials & Continua 2021, 68(3), 3629-3652. https://doi.org/10.32604/cmc.2021.017333

Received 27 January 2021; Accepted 19 March 2021; Issue published 06 May 2021

Abstract

This pilot study focuses on a real measurements and enhancements of a software defined radio-based system for vehicle-to everything visible light communication (SDR-V2X-VLC). The presented system is based on a novel adaptive optimization of the feed-forward software defined equalization (FFSDE) methods of the least mean squares (LMS), normalized LMS (NLMS) and QR decomposition-based recursive least squares (QR-RLS) algorithms. Individual parameters of adaptive equalizations are adjusted in real-time to reach the best possible results. Experiments were carried out on a conventional LED Octavia III taillight drafted directly from production line and universal software radio peripherals (USRP) from National Instruments. The transmitting/receiving elements used multistate quadrature amplitude modulation (M-QAM) implemented in LabVIEW programming environment. Experimental results were verified based on bit error ratio (BER), error vector magnitude (EVM) and modulation error ratio (MER). Experimental results of the pilot study unambiguously confirmed the effectiveness of the proposed solution (longer effective communication range, higher immunity to interference, deployment of higher state QAM modulation formats, higher transmission speeds etc.), as the adaptive equalization significantly improved BER, MER and EVM parameters. The best results were achieved using the QR-RLS algorithm. The results measured on deployed QR-RLS algorithm had significantly better Eb/N0 (improved by approx. 20 dB) and BER values (difference by up to two orders of magnitude).

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Keywords

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