Latency-Constrained Fading Mitigation for Coherent Optical Feeder Links based on Space-Time-Frequency Coding

Latency-Constrained Fading Mitigation for Coherent Optical Feeder Links based on Space-Time-Frequency Coding

Korevaar, C.W. (TU Delft BUS/TNO STAFF; DIANA FEA)
Saathof, R. (TU Delft Space Systems Egineering)
van Abkoude, Tara (DIANA FEA)
Doelman, Niek J. (DIANA FEA; Universiteit Leiden)

Minoglou, Kyriaki (editor)
Karafolas, Nikos (editor)
Cugny, Bruno (editor)

2023

Optical feeder links (OFLs) benefit from the vast amount of bandwidth available in the THz-regime of the electromagnetic spectrum, and can be considered as enablers for future terabit-per-second satellite systems. A particular challenge for OFLs is to mitigate the effects of fading, caused by a combination of turbulence-induced scintillation, beam wander and pointing errors. The conventional solution is to exploit temporal diversity by a combination of interleaving and forward error correction (FEC). In this study we present an overview of fading mitigation techniques for latency-constrained coherent ground-to-satellite OFL and contribute a generic model which combines various diversity schemes including temporal, spatial, frequency and site diversity. To unlock spatial diversity, multi-beam space-time block coding and multi-beam, multi-λ are proposed and simulated. Though space-time block coding (STBC) provides more diversity gain, it requires accurate timing synchronization at the transmitter and channel state information at the receiver. Temporal, frequency and site diversity all rely on some form of interleaving and the potential diversity, pros and cons of each of these diversity techniques are covered in the presented study. In general, with a strict latency constraint and a tight link budget, frequency diversity, spatial diversity - either by STBC or multi-beam multi-λ - and site diversity can be effective methods to mitigate the effects of fading and close the link budget.

diversity
fading
free space optics
ground-to-satellite
Optical feeder links
space-time block coding
spatial diversity
turbulence

http://resolver.tudelft.nl/uuid:2b73cbf3-8199-4964-a3f9-82f53b27edc4

https://doi.org/10.1117/12.2690891

SPIE

9781510668034

International Conference on Space Optics, ICSO 2022

2022 International Conference on Space Optics, ICSO 2022, 2022-10-03 → 2022-10-07, Dubrovnik, Croatia

Proceedings of SPIE - The International Society for Optical Engineering, 0277-786X, 12777

This study has been conducted as part of the TNO Early Research Program “Laser Satellite Communication - High Throughput Optical Feeder Links”.

Institutional Repository

conference paper

© 2023 C.W. Korevaar, R. Saathof, Tara van Abkoude, Niek J. Doelman