Radio communications should travel perfectly through space, right? Well, not exactly, as it turns out. There’s plenty to interfere with radio communications away from the surface of Earth, including (but not limited to) cosmic noise and our planet’s fluctuating ionosphere that is perfectly capable of impairing the link between satellite and ground station.
To try and get around this problem, which could disrupt future space missions, researchers from Worcester Polytechnic Institute and Penn State University have been working with NASA to test what they call cognitive radios. These smart radios use artificial neural networks to adjust their settings in real time, optimizing their ability to stay in contact even under challenging circumstances. As such, they could be game-changers in difficult space environments where getting a human to reconfigure them may be next to impossible. In the team’s tests, the cognitive radios were able to maintain a clear signal between the International Space Station (ISS) and the ground.
“Our cognitive radio maps the relationship between the parameters and the performance values of the space communication system, as well as includes the environmental conditions such as the signal-to-noise ratio, using an approach called reinforcement learning neural networks,” Alex Wyglinski, professor of electrical engineering and robotics engineering at Worcester Polytechnic, told Digital Trends.
“This approach works by having the cognitive radio ‘agent’ continuously receive information from the space communication environment about how well everything is going — ‘rewards’ — and [the] current configuration of the communication system, [referred to as] ‘states,’” he continued. “The agent feeds this information into an ensemble of neural networks, which produces a set of potential actions to be performed by the communication system. The actions with the potential to yield the best performance [are] then applied to the space communication system.”
The concept of cognitive radios dates back to 1998. Several prototypes have been built over the years, including models by the U.S. Department of Defense. But building a cognitive radio for space turns out to be a bit more difficult. To put it mildly.
“For our proof-of-concept space cognitive radio system, we designed and built a framework that would enable robust communications in a space environment, which is something much more challenging relative to similar wireless applications on Earth,” Wyglinski explained.
Sven Bilén, professor of engineering design, electrical engineering, and aerospace engineering at Penn State, told Digital Trends: “Our system is unique in that we are the first in-space test of cognitive communications.”
The researchers recently wrote an article about their work for IEEE Spectrum.
