New modeling approach of laser communication in constellation and through atmospheric disturbances

Abstract

Laser communication between satellites in the constellation and from the satellites to ground stations offers a gigantic data rate for the users. This principal advantage drives telecom companies to develop this technology to use it like a carrier signal, the most disadvantage of this technology is the need to very complicated pointing systems between the transmitter and the receiver due to a very small beam divergence, continually moving of satellites in orbits and the distance between the satellites (tens of thousands of kilometers). The laser beam suffers continuously from several factors like atmospheric turbulences, internal and external vibrations. All these factors lead to an increase in the bit errors rate and cause degradation in the communication quality. This paper deals with a new method of modelisation of external effects in transmission of signal light from a ground station to the satellite through atmospheric disturbances. Indeed, an in-depth investigation, of the influences of satellite vibrationsinlaser signal transmission between satellites constellation, has been conducted by studying the effect of the intensity of vibrations on the optical signal amplitude. Some solutions are proposed to improve the efficiency of optical satellites communications.

Secure hybrid fiber optic and free optical space communication systems

“…The FSO transmission part has been operated with 1mrad divergence angle and 20dB amplifier gain with different attenuation range from 0.4 dB/km (in clear weather) to 242 dB/km and 304 dB/km (in heavy dust and fog respectively). The attenuation is calculated by Kim model with a visibility of 70 m and 49 m respectively as in [6], [7]. Where the atmospheric attenuation coefficient according to Kim model equals to [5], [24].…”

“…Many previous studies addressed in this perspective to investigate how to reduce the impact of attenuation [6], [7]. Different techniques like orthogonal frequency division multiplexing-FSO and wavelength-division multiplexing-FSO based system are new approach to improve the system performance with high speed and longer distance [8].…”