ESTIMATING METHOD OF COMMUNICABLE DISTANCE IN VISIBLE LIGHT COMMUNICATION

• Main Authors: FUKUOKA SHIGERU, MORISAWA TOMOHIRO, YASUTOSHI TOSHIYUKI, AMINO TAKAHIKO
• Format: Patent
• Language: English; Japanese
• Published: 17.06.2021
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

To provide a method capable of easily estimating a communicable distance at a desired communication speed when visible light communication is performed under a target environmental condition.SOLUTION: Under an environmental condition in which a transmittance c of visible light V is known, a transmitting device 1 irradiates a receiving device 2 with the visible light V, and the transmittance c under the environmental condition, a separation distance L from the transmitting device 1 to the receiving device 2, and an irradiance E of the receiving device 2 are substituted into a formula (1), a light source intensity I of the transmitting device 1 is calculated, and the irradiance E corresponding to a desired communication speed is grasped, (E=I cL/L2 (1)), and under a target environmental condition, the transmitting device 1 irradiates the receiving device 2 with the visible light V, and the separation distance L and the irradiance E at that time and the pre-calculated light source intensity I are substituted into the formula (1), and the transmittance c under the target environmental condition is calculated, and the calculated transmittance c, the grasped light source intensity I, and the irradiance E corresponding to the desired communication speed are substituted into the formula (1) to estimate a communicable distance L.SELECTED DRAWING: Figure 1 【課題】対象環境条件下において可視光通信を行うときの所望の通信速度での通信可能距離を簡便に推定できる方法を提供する。【解決手段】可視光Ｖの透過率ｃが既知の環境条件下で、送信装置１から受信装置２に可視光Ｖを照射し、その環境条件下の透過率ｃと送信装置１から受信装置２までの離間距離Ｌと受信装置２の放射照度Ｅとを（１）式に代入して送信装置１の光源強度Ｉを算出し、所望の通信速度に対応する放射照度Ｅを把握し、Ｅ＝Ｉ・ｃＬ／Ｌ２...（１）対象環境条件下において、送信装置１から受信装置２に可視光Ｖを照射し、その際の離間距離Ｌおよび放射照度Ｅと予め算出した光源強度Ｉとを、（１）式に代入して対象環境条件下の透過率ｃを算出し、算出した透過率ｃと把握した光源強度Ｉと所望の通信速度に対応する放射照度Ｅとを、（１）式に代入して通信可能距離Ｌを推定する。【選択図】図１