The Effects of Power Control on Free-Space Optical Communications during Snowfall and Rainfall

• 作者: Ahmed Mohamed Abdalla Mahmoud Alnaser Mubarak Alhajri Muhammad A. Alsubaie Salem Salamah
• 来源期刊: 通讯、网络与系统学国际期刊(英文)
• 学科: 医学
• 关键词: Free Space Optical Communications SNOW ATTENUATION RAIN ATTENUATION Power Control
• 年，卷（期）: 2018,（10）
• 页码范围: 216-227
• 页数: 12页
• 分类号: R73

摘要

Free-space optical (FSO) communication requires a line-of-sight connection between a transmitter and a receiver in which the information signal is modulated by an optical carrier that propagates in free space. The FSO channel is greatly affected by weather conditions such as fog, rain, and snow. In the literature, several adaptive techniques, such as power control (PC), have been suggested to mitigate channel link degradations. In this paper, we investigate the effects of snow and rain attenuation on the bit error rate (BER) of the FSO system using two types of modulations, the on-off keying (OOK) modulation and the pulse-position modulation (16-PPM). The effect of PC on the performance of FSO communications is also examined in this study. We evaluated the system’s performance with two types of snow, wet snow and dry snow, as well as with different rain regions. Results show that PC improves the BER of the FSO system;a high rate of improvement is found for wet snow and rain. PC has almost no effect with dry snow because of the high attenuation and the limitations on transmitted power. The BER for 16-PPM is better than that for OOK modulation.