Beam Divergence Loss Mitigation in Free Space Optical Communication Channel Using Field of View Technique

Gambo D.,Tekanyi A.M.S., Musa M.J, Al-Mustapha M.D. and Ya’u 

Keywords:fog, rain, beam divergence, BER, and NSR


A rapid advancement in the electronics and telecommunications industries has been observed. As a result,
Communication gadgets are becoming more powerful and are more widely adopted. The demand for high data rate
transmission is increasing. This has led to spectrum scarcity in Radio Frequency (RF) systems. Consequently, it is
necessary to explore other technical means to meet the increasing demand for higher data rates. Free Space Optical
Communication (FSOC) is a promising technology that offers one of such means. However, the major technical
challenge in the FSOC systems is that, their performance is limited by atmospheric impairments such as: absorption,
scattering and turbulence caused by rain, cloud, snow, wind, dust, aerosol, and fog. This research is aimed to
addressed beam divergence challenge due to fog and raindrop in a tropical climate using wider field of view technique
(FoV). The result showed that, for the fog measurement using mini solar panel at the receiver, the system achieved
higher SNR of 60 dB at corresponding BER of 10-4
. While, with the photodiode, the system achieved an SNR of 38 dB
at same BER. For the rain measurement the same procedure was adopted and the system achieved higher SNR of 90
dB and 58 dB at same BER utilizing both solar panel and photodiode respectively. The result showed that, the fog
impairment attenuates optical signal more than of rain by 34 % averagely.