Multi-hop DF relayed FSO links with various modulation formats emulated by a dual-hop scheme for strong turbulence conditions

• Published in: Optik (Stuttgart) 2021-02, Vol.227, p.165972, Article 165972
• Main Authors: Androutsos, N.A., Nistazakis, H.E., Petkovic, M.I., Djordjevic, G.T., Stassinakis, A.N., Volos, C.K.
• Format: Article
• Language: English
• Subjects: Atmospheric turbulence; DF relays; K distribution model; Modulation format; Multi-Hop; Negative exponential distribution; Terrestrial FSO
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2020.165972

In this work, we try to minimize the mathematical complexity in analyzing outage and error performance by emulating multi-hop terrestrial FSO communication system as a single dual-hop scheme. More specifically, we approximate the topology of such a system and we estimate analytically its performance, by taking into account various modulation formats for strong and saturated atmospheric turbulence conditions. The theoretical study of the FSO system performance is performed using either the negative exponential or the K distribution models, while the well-known modulation formats on-off keying (OOK), pulse amplitude modulation (PAM) and pulse position modulation (PPM), have been employed. Thus, closed form mathematical expressions for outage probability and average BER estimation are derived and their outcomes can easily be used for the design of modern optical wireless links. Finally, using the obtained mathematical forms, the corresponding numerical results are presented using realistic FSO parameter values.