Adaptive radio technology for satellite communications
The satellite industry in the U.S. suffers from spiraling costs, out-of-control development cycles, and diminishing performance. The recent NASA Orbiting Carbon Observatory satellite took $280 million and 8 years to develop before it plunged into the Indian Ocean due to a launch vehicle malfunction in February 2009. High-risk satellite programs foster ever-increasing conservatism and technological risk-aversion, which stifles innovation.
CubeSats (10 cm³ small satellites) are a disruptive technology, requiring a few million dollars and less than 2 years to develop, which allows greater tolerance for risk. Currently, 15% of the satellites launched are CubeSats; however, communications is a critical CubeSat deficiency. Current technology can only offer downlinks of tens of kilobits per second due to constrained power budgets and conventional radio design. Satellite-to-ground communication links are highly dynamic due to factors such as atmospheric thermal noise, propagation distance, Doppler effects, and antenna misalignment. These factors limit the amount of information the satellite can transmit and the ground station can receive.
In response to these problems, Los Alamos National Laboratory (LANL) developed a radio that varies the satellite’s rate of data transmission based on commands from a modified ground station. Using LANL’s Adaptive Radio Technology (ART), ground terminals continuously assess link conditions and automatically compensate with transmission change commands to the satellite (i.e., send more or less data as conditions warrant). The communication link achieves high energy efficiency and accuracy by maximizing the available channel capacity, which in turn enhances link robustness. This has the benefit of permitting compatibility with a variety of ground stations. LANL’s innovation will allow CubeSats to be used in larger, more critical missions.
Adaptive Radio Technologies, LLC licensed the new waveform invented at LANL to incorporate it into a software-defined radio hardware platform that can be used on CubeSats by academia, industry and government.