Space-to-ground radio frequency (RF) communications transfer critical data that enables successful satellite and spacecraft operations. Such communications are susceptible to co-channel interference produced by terrestrial or space-based sources, and to interfering signals from shared spectrum scenarios. If radio frequency interference (RFI) could be detected and mitigated in an automated fashion, link performance and reliability could be improved.
After observing unexpected interference events during space-to-ground communications, innovators from the NASA Glenn Research Center developed a software-based automated RFI mitigation system to increase communication reliability.
This invention detects interfering RF signals using signal processing techniques and intelligently mitigates the interference by automatically changing communication link parameters. The system continuously optimizes the link to improve data-rate transfer and link reliability in a dynamic environment.
The interference mitigation system is composed of several algorithms that allow it to detect and respond to interference and optimize the link based on a given set of mission objective weights. The system runs in real-time, continuously ingesting link information from the receiving modem and spectrum information from the monitoring subsystem.
This information then feeds into an Adaptive Coding and Modulation (ACM) loop and a mitigation subsystem. The ACM loop uses algorithms to decide if mitigation should take place and, if so, what mitigation actions are available to consider. These actions are then ranked using a multi-objective, weighted-sum algorithm and the best-ranked action is chosen and applied to the link by the link controller.
During testing at NASA, the RFI mitigation system was shown to achieve the highest average throughput over all test cases compared to alternative mitigation strategies. The technology is useful for space-to-ground communications, satellite communications, and RF communications.
NASA is actively seeking licensees to commercialize this technology. Please contact NASA’s Licensing Concierge at