Analysis of scintillation effects along a 7  km urban space laser communication path

Abstract

In this study, the scintillation effects along a 7 km space laser communication path in an urban area were examined, including the relationship between the scintillation and bit error rate and the variation of the scintillation index with changes in the transmitting and receiving apertures. It was concluded that multi-aperture transmitting technology can effectively reduce the scintillation caused by atmospheric turbulence. For the investigated urban link, the scintillation index could meet the communication requirements for adjusting the receiving aperture. These results will facilitate space laser communication improvement and turbulence suppression along horizontal urban paths.

Coherent Free-Space Optical Communications: Opportunities and Challenges

“…From the observation of Fig. 13, it can be concluded that 10 −5 < σ 2 l < 10 −2 , which corresponds to a low turbulence regime, as expected for a short link length of 42 m. In addition, the range of atmospheric refractive-index structure parameter, 10 −16 < C 2 n < 10 −13 , is well matched with the typical values found in other FSO turbulence studies [31], spanning from low (C 2 n ≃ 10 −16 m -2/3 ) to average (C 2 n ≃ 10 −14 m -2/3 ) turbulence, which further confirms that while the turbulence phenomena is indeed present on the link, its manifestation in terms of received optical power variance is minor due to the low link length (note the L 11/6 dependence of the Rytov variance in (3)). Also note that, for the range of measured Rytov variances, the scintillation index,…”

“…Despite the ultra-high capacity enabled by FSO, its widespread commercial adoption still faces a handful of critical challenges, mainly in terms of communication reliability. Among these, the two major technical issues that span across most FSO applications are i) the impact of atmospheric turbulence [31], [32] and ii) the tight requirements on optical beam alignment [33], [34]. Atmospheric turbulence is a key distinguishing feature of FSO channels: unlike fiber-based systems, the received optical signal suffers from random power fluctuations, a phenomenon that is commonly denominated as optical scintillation [35].…”