TY - GEN
T1 - A new ground-to-train communication system using free-space optics technology
AU - Kotake, H.
AU - Matsuzawa, T.
AU - Shimura, A.
AU - Haruyama, S.
AU - Nakagawa, M.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006
Y1 - 2006
N2 - We propose a new ground-to-train communication system using free-space optics between a train and the ground. In the proposed system, a cylindrical concave lens spreads the incoming beam from transmitter (Laser Diode, LD) horizontally to form a wide fan-shaped beam. The fan-shaped beam is projected to a train and the width of the projected beam is equal to the length of a typical bullet-train car. This transmitter with cylindrical concave lens and a receiver (Avalanche Photo Diode, APD) are installed on a train and the ground, and the horizontally spread beam is received continuously by the corresponding receiver. The train can keep a communication link continuously to the ground thanks to this spread beam. We analyzed the performance of the proposed system by experiments. The experimental results show that a sufficient received Signal-to-Noise Ratio (SNR) can be obtained when a train is not moving; therefore, the signal can be received continuously even when the train is moving. Furthermore, in order to keep a continuous communication link even when the train vibrates or shifts vertically, the vertical spread angle of a laser beam is adjusted between 0.1 degrees and 0.5 degrees. These experimental results lead to the conclusion that this system is expected to be a Giga-bit class high speed communication technology between the train and the ground.
AB - We propose a new ground-to-train communication system using free-space optics between a train and the ground. In the proposed system, a cylindrical concave lens spreads the incoming beam from transmitter (Laser Diode, LD) horizontally to form a wide fan-shaped beam. The fan-shaped beam is projected to a train and the width of the projected beam is equal to the length of a typical bullet-train car. This transmitter with cylindrical concave lens and a receiver (Avalanche Photo Diode, APD) are installed on a train and the ground, and the horizontally spread beam is received continuously by the corresponding receiver. The train can keep a communication link continuously to the ground thanks to this spread beam. We analyzed the performance of the proposed system by experiments. The experimental results show that a sufficient received Signal-to-Noise Ratio (SNR) can be obtained when a train is not moving; therefore, the signal can be received continuously even when the train is moving. Furthermore, in order to keep a continuous communication link even when the train vibrates or shifts vertically, the vertical spread angle of a laser beam is adjusted between 0.1 degrees and 0.5 degrees. These experimental results lead to the conclusion that this system is expected to be a Giga-bit class high speed communication technology between the train and the ground.
KW - Horizontally spread beam
KW - Optical wireless communication
KW - Train communication
KW - Visible light communication
UR - http://www.scopus.com/inward/record.url?scp=36148966613&partnerID=8YFLogxK
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U2 - 10.2495/CR060671
DO - 10.2495/CR060671
M3 - Conference contribution
AN - SCOPUS:36148966613
SN - 1845641779
SN - 9781845641771
T3 - WIT Transactions on the Built Environment
SP - 683
EP - 692
BT - Computers in Railways X
T2 - 10th International Conference on Computer System Design and Operation in the Railway and Other Transit Systems, COMPRAIL 2006, CR06
Y2 - 10 July 2006 through 12 July 2006
ER -