This Chinese satcom tech transmits data 5x faster than Starlink
What's the story
A team of Chinese scientists has achieved a major breakthrough in satellite communication.
They have successfully transmitted data at a staggering speed of 1Gbps from a stationary satellite, positioned over 36,000km above Earth. The transmission was done using just a simple 2W laser.
This is five times faster than the current maximum speed offered by Elon Musk's Starlink satellites, which operate hundreds of kilometers above the Earth.
Technological challenge
Dealing with atmospheric turbulence
Satellite laser downlinks are incredibly fast, but they have to deal with atmospheric turbulence.
This phenomenon scatters the light into extremely weak and fuzzy patches hundreds of meters wide by the time it reaches the ground.
To tackle this problem, researchers have previously used adaptive optics (AO) and mode diversity reception (MDR). However, neither method was effective alone under strong turbulence conditions.
Innovative approach
Proposed method and experiment
The team of scientists, led by Wu Jian from Peking University and Liu Chao from the Chinese Academy of Sciences, proposed a novel solution called AO-MDR synergy.
They said this method "effectively prevents communication quality degradation caused by extremely low signal power."
The system was tested at a Lijiang observatory in southwest China using a 1.8-meter telescope targeting an unnamed satellite 36,705km away.
Test details
How the system works
The telescope used in the experiment was equipped with 357 micro-mirrors that could reshape warped laser light and reduce wavefront distortion.
A multi-plane converter (MPLC) split light entering a multi-mode fiber into eight base-mode channels.
The three strongest signals were selected and merged in real-time via a "path-picking" algorithm driven by tailor-made chips.
This method led to a significant increase in signal strength, with AO+MDR providing more gain than AO alone at critical signal-reliability thresholds.
Improved performance
China at the forefront of space laser technology
The new method also drastically reduces errors, with the chance of usable signals jumping from 72% to 91.1%. This is extremely important for high-value data transmission.
The researchers observed this multiplicative effect consistently across multiple experimental verifications.
China has been at the forefront of space laser communication technology, having previously achieved a world record with 10Gbps laser downlinks from geostationary orbit in 2020 using its Shijian-20 satellite.