High-speed visible light communication using spatial coherence synthesis of multiple LED light modulated subcarriers

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04047
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21020:Communication and network engineering-related
• Research Institution: Meijo University
• Principal Investigator: Chujo Wataru 名城大学, 理工学部, 教授 (40292289)
• Co-Investigator(Kenkyū-buntansha): 小林 健太郎 名城大学, 理工学部, 准教授 (40583878)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 可視光通信 / イメージセンサ / ローリングシャッター / 空間分割多重 / 波長分割多重 / デジタルサイネージ / 均等色空間 / ダイバシチ

Outline of Final Research Achievements

Spatial coherence synthesis of incoherent modulated lights from an LED lighting or display transmitter to an image sensor receiver was achieved.
In image sensor spatial synthesis, symbol decision was achieved using cells that combined spatial 4 pulse position modulation. It was achieved using only clustering and correlation without threshold learning. In dual camera spatial synthesis, phase shift keying using subcarrier modulation of backlight LED was realized by γ characteristic correction that takes both the overlay image and modulation into account. In overlap data spatial synthesis, superiority of Jzazbz uniform color space was revealed.
In photodiode spatial synthesis, object detection of a camera with short exposure time was used to learn the difference between the transmitter and lightings. It achieved 600 Mbps throughput with optical axis alignment accuracy of 0.1°.

Free Research Field

可視光通信

Academic Significance and Societal Importance of the Research Achievements

周囲光や重畳画像の影響により，機械学習などの事前学習に基づくシンボル判定は困難となる．空間分割多重で空間4パルス位置変調パターンの相関を用いたシンボル判定，複眼カメラでバックライトLEDのサブキャリア変調信号の重畳画像補正，Jzazbz均等色空間の優位性，何れも事前学習なしでシンボル判定を実現した点は学術的意義が大きい．
電波では衝突や干渉が生じる多数機器で構成される無線通信ネットワークに対応する光技術として，LED照明やディスプレイを送信機，イメージセンサを受信機に用いて空間合成を実現した点，更にフォトダイオードとカメラを組み合わせた高スループットの空間合成に発展できた点に社会的意義がある．