A 4 × 20 Gbps inter-satellite optical wireless communication system based on orbital angular momentum multiplexing: performance evaluation

Optical Wireless Communication (OWC) technology, owing to its numerous merits including high-speed transmission, large modulation-bandwidth, security, and cost-effectiveness, has been considered for many applications including terrestrial links, indoor wireless transmission, underwater transmission, hybrid radio-frequency/free space optics links, and space applications. Inter-satellite OWC links are one of the most crucial applications of OWC technology, which can be used to transmit data from one part of the globe to other to achieve global connectivity. On the other hand, Orbital Angular Momentum (OAM) multiplexing is an emerging data-transmission technology used to increase the throughput and spectral-efficiency of optical links. In this work, we report, the integration of OAM multiplexing with inter-satellite OWC link to achieve high-speed information transmission for space applications. 4 OAM beams ( \({LG}_{0}^{0}, {LG}_{13}^{0}, {LG}_{40}^{0},\) ${\mathit{LG}}_0^0,{\mathit{LG}}_{13}^0,{\mathit{LG}}_{40}^0,$ and \({LG}_{80}^{0})\) ${\mathit{LG}}_{80}^0)$ are used to transmit independent 20 Gbps binary data over an OWC channel between two satellites. A net transmission speed of 80 Gbps is achieved. The performance of the proposed inter-satellite WC link based on OAM transmission is evaluated through range, misalignment pointing errors, additional losses due to solar radiations, and laser transmission power using numerical simulations. The proposed system demonstrates a reliable 80 Gbps transmission over 10000 km inter-satellite link distance at 30 dBm laser power under the influence of 1.6 µrad pointing error and 5 dB additional losses with log(BER) \(\le\) $\le$ − 5. Furthermore, as the pointing error is reduced to 1 µrad, the transmission range is increased from 10000 to 12000 km with log(BER) \(\le\) $\le$ − 5.