Abstract
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.
| Original language | English (US) |
|---|---|
| Article number | 7885601 |
| Pages (from-to) | 7677-7687 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Vehicular Technology |
| Volume | 66 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2017 |
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Electrical and Electronic Engineering
- Computer Networks and Communications
- Automotive Engineering
Keywords
- Free-space optical (FSO) communications
- beam divergence angle
- high-speed train communications
- narrow beam
- optical wireless communications
- wide beam