Study on High-Speed, Two-Way, and Multi-Access Visible Light Communication by Image Sensor and LED Array

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K06371
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Communication/Network engineering
• Research Institution: Meijo University
• Principal Investigator: CHUJO WATARU 名城大学, 理工学部, 教授 (40292289)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 可視光通信 / イメージセンサ / ローリングシャッター / 空間輝度分布 / 空間多重 / スマートフォン / LED / LCD

Outline of Final Research Achievements

High-speed, two-way, and multi-access optical camera communication was achieved. Downlink consists of LED lighting transmitter and smartphones’ built-in camera receiver. Uplink consists of smartphones’ built-in LCD display transmitter and indoor surveillance camera receiver.
To increase the symbol rate for downlink, we developed rolling-shutter asynchronous communication with variable symbol rates based on a cycle pattern of received symbols, ensemble average using dual rolling-shutter camera, and threshold decision based on spatial luminance distribution. On the other hand, adaptive thresholding considering spatial inter-symbol interference was developed for uplink.
In downlink, 156k symbol/s was achieved with LED array and smartphones’ built-in rolling-shutter camera. In uplink, 168.75k symbol/s was achieved with smartphones’ built-in LCD display and indoor camera based on space division multiplexing.

Free Research Field

可視光通信

Academic Significance and Societal Importance of the Research Achievements

本研究では，既存のスマートフォン内蔵カメラと液晶ディスプレイ，LED照明と室内カメラを用いて双方向可視光通信を実現した．スマートフォンを用いて双方向可視光通信を実現した例は，国内外を含めてなく独自のシステムであり学術的意義は高い．
可視光は電波に比べて，免許や混信，情報漏洩の心配がなく，安全・安心に利用することができる．モノのインターネット(IoT)には環境に適応した様々な通信手段が必要と考えられる．電波にない特長を有する可視光通信をイメージセンサを用いて双方向化し，高速化できたことは社会的に意義がある．