Relayed FSO Links for Ground-to-Train Communications

Relay assisted FSO, which is primarily used as a fading mitigation technique, can be employed to reduce the impact of network layer handover in the context of HST communications. In this paper, we propose a relay-based FSO system to provide ground to train communications and relays the information to the next base stations. Two schemes are analyzed via numerical simulations namely (i) all optical amplify and forward (AOAF); and (ii) AOAF with optical and optical-electronical-optical regeneration schemes in terms of the bit error rate performance and transmission range attained.