TY - JOUR
T1 - On Divergence-Angle Efficiency of a Laser Beam in Free-Space Optical Communications for High-Speed Trains
AU - Kaymak, Yagiz
AU - Rojas-Cessa, Roberto
AU - Feng, Jianghua
AU - Ansari, Nirwan
AU - Zhou, Mengchu
N1 - Funding Information:
Manuscript received February 24, 2016; revised May 31, 2016, October 21, 2016, and January 27, 2017; accepted February 22, 2017. Date of publication March 23, 2017; date of current version September 15, 2017. This work was supported in part by CRRC Zhuzhou Institute Co., Ltd. The review of this paper was coordinated by Prof. Xuming Fang. (Corresponding author: Yagiz Kaymak.) Y. Kaymak, R. Rojas-Cessa, N. Ansari, and M. Zhou are with the Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ 07102 USA (e-mail: yk79@njit.edu; rojas@njit.edu; ansari@njit.edu; zhou@njit.edu).
Publisher Copyright:
© 2017 IEEE.
PY - 2017/9
Y1 - 2017/9
N2 - We compare narrow and wide laser beams in a free-space optical (FSO) communications system for high-speed train communications and analyze the tradeoffs among the received power, coverage area, and the complexity of the acquisition-tracking-pointing (ATP) mechanism. We propose to employ a divergence angle of a wide beam in the range [0.07, 2.002] to relax the steering speed of the fast steering mirror, which is a major component of the ATP mechanism in an FSO transceiver. In addition, we overcome the negative effects of train vibrations by using a proposed divergence-angle range for a wide beam. The proposed range of divergence angles provides a large link range and effective coverage length, and contact time as compared to a narrow beam.
AB - We compare narrow and wide laser beams in a free-space optical (FSO) communications system for high-speed train communications and analyze the tradeoffs among the received power, coverage area, and the complexity of the acquisition-tracking-pointing (ATP) mechanism. We propose to employ a divergence angle of a wide beam in the range [0.07, 2.002] to relax the steering speed of the fast steering mirror, which is a major component of the ATP mechanism in an FSO transceiver. In addition, we overcome the negative effects of train vibrations by using a proposed divergence-angle range for a wide beam. The proposed range of divergence angles provides a large link range and effective coverage length, and contact time as compared to a narrow beam.
KW - Free-space optical (FSO) communications
KW - beam divergence angle
KW - high-speed train communications
KW - narrow beam
KW - optical wireless communications
KW - wide beam
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U2 - 10.1109/TVT.2017.2686818
DO - 10.1109/TVT.2017.2686818
M3 - Article
AN - SCOPUS:85029951833
SN - 0018-9545
VL - 66
SP - 7677
EP - 7687
JO - IEEE Transactions on Vehicular Technology
JF - IEEE Transactions on Vehicular Technology
IS - 9
M1 - 7885601
ER -