Abstract:Complementing wireless radio networks with free-space optics (FSO) achieves high data rates by modulating radio subcarriers over an optical carrier without expensive optical fiber cabling, enabling a pervasive platform for reaching underserved areas. In this paper, we review the main features of FSO for terrestrial and inter-satellite communications. Simulations of 1 Gbps data transmission through FSO links in both terrestrial and inter-satellite communications have been investigated to highlight potential atmospheric challenges in FSO.

Free space optics (FSO) technology provides a promising solution for future broadband networks, offering high data transmission compared to RF technology. This work is focused on investigating the performance of an FSO system with OFDM and QAM. A 10 Gbps data stream is transmitted using a 4-level QAM sequence through the FSO system under different atmospheric conditions. Results indicate that the integration of SOA prolongs the maximum achievable distance with acceptable SNR to 185 km under clear weather conditions whereas under atmospheric fog, the maximum distance is extended to 2.5 km.

No abstract

No abstract

Inter-satellite communication is a revolutionary technique used to establish communication between satellites in space. One of the major challenges in inter-satellite link is transmitting pointing errors, which causes turbulences in the link. This work is focussed on successful transmission of 120 Gbps high-speed data over 1,000 km by adopting hybrid wavelength division multiplexing scheme and polarization interleaving scheme under the influence of transmitting pointing error.

No abstract

Radio-over-free-space (Ro-FSO) technology is a combination of free-space optics (FSO) and wireless communication systems. It plays a significant role in radio-frequency signal transmission in mobile network communication through high-speed optical carrier without any licensing and costly cables. Photonic crystal fibers also play a significant role to deliver data at faster rate for short haul communication. This paper, for the first time to the author's best knowledge, utilizes mode division multiplexing in conjunction with solid core PCFs to transmit 2 x 2.5Gbps-5GHz data over 2.5 km free space link. The results are reported in terms of Bit error rate (BER), spatial profiles of received modes, mode spectrum of modes and eye diagrams. Furthermore, proposed PCF-MDM-Ro-FSO transmission system is also reported under the impact of atmospheric turbulences.

Radio-over-Free-Space-Optics (Ro-FSO) is a promising technology for future wireless networks. In this work, we have designed a hybrid orthogonal frequency division multiplexing (OFDM) Ro-FSO system for transmission of two independent channels by mode division multiplexing. Two independent 40 GHz radio signals are optically modulated at 20Gbps by mode division multiplexing of two laser modes LG00 and LG10 and transmitted over a free-space link of 20 km to 100 km. The performance of proposed Ro-FSO system is also evaluated under the effect of strong atmospheric turbulences.