Academic Journal
Real‐Time Software‐Defined Adaptive MIMO Visible Light Communications
| Title: | Real‐Time Software‐Defined Adaptive MIMO Visible Light Communications |
|---|---|
| Authors: | Deng, Peng |
| Source: | MODID-6d55e02e354:IntechOpen |
| Publisher Information: | IntechOpen |
| Publication Year: | 2017 |
| Subject Terms: | Technology & Engineering / Optics, bisacsh:TEC030000 |
| Description: | Visible light communications (VLC) based on light-emitting diodes (LEDs) merges lighting and data communications in applications of Internet-of-Things and 5G networks. However, phosphor-based white LED has a limited linear dynamic range and limited modulation bandwidth. In practical indoor mobile communications, complex channel conditions change dynamically in real-time, and line of sight (LOS) links may be blocked by obstructions. We propose a real-time software-defined adaptive multi-input multi-output (MIMO) VLC system, that both modulation formats (QPSK,16-QAM,64-QAM, 256QAM) and MIMO reconfigurations (Spatial Diversity and Spatial Multiplexing) are dynamically adapted to the changing channel conditions, for enhancing both link reliability and spectral efficiency. Real-time and software defined digital signal processing (DSP) are implemented by Field Programmable Gate Array (FPGA) based Universal Software Radio Peripheral (USRP) devices. We theoretically analysed and experimentally evaluated nonlinear electrical-optical properties and modulation characteristics of white LEDs. We demonstrated a real-time Single-Carrier 256-Quadrature Amplitude Modulation (QAM) 2×2 MIMO VLC, achieving 1.81% averaged error vector magnitude (EVM), 2×10-5 bit error rate (BER) after 2 m indoor transmission. As an obstacle moved across LOS links, real-time software-defined adaptive MIMO VLC system enhanced average error-free spectral efficiency of 12 b/s/Hz. This will provide high throughputs for robust links in mobile shadowing environments. |
| Document Type: | article in journal/newspaper |
| File Description: | application/pdf |
| Language: | English |
| ISBN: | 978-953-51-3407-7 953-51-3407-8 |
| DOI: | 10.5772/intechopen.68919 |
| Availability: | https://openresearchlibrary.org/viewer/5ae133db-e85d-4ad0-91f0-047dd93ca9f1 https://openresearchlibrary.org/ext/api/media/5ae133db-e85d-4ad0-91f0-047dd93ca9f1/assets/external_content.pdf https://doi.org/10.5772/intechopen.68919 |
| Rights: | https://creativecommons.org/licenses/by/4.0/legalcode |
| Accession Number: | edsbas.8D7B0C11 |
| Database: | BASE |
| ISBN: | 9789535134077 9535134078 |
|---|---|
| DOI: | 10.5772/intechopen.68919 |