Extension on Adaptive MAC Protocol for Space Communications

• Main Author: Li, Max Hongming
• Other Authors: Donald Richard Brown III, Committee Member
• Format: Others
• Published: Digital WPI 2018
• Subjects: Catastrophic Forgetting; Deep Reinforcement Learning; DVB-S2; Machine Learning; NASA; Space Communications
• Online Access: https://digitalcommons.wpi.edu/etd-theses/1275; https://digitalcommons.wpi.edu/cgi/viewcontent.cgi?article=2270&context=etd-theses

This work devises a novel approach for mitigating the effects of Catastrophic Forgetting in Deep Reinforcement Learning-based cognitive radio engine implementations employed in space communication applications. Previous implementations of cognitive radio space communication systems utilized a moving window- based online learning method, which discards part of its understanding of the environment each time the window is moved. This act of discarding is called Catastrophic Forgetting. This work investigated ways to control the forgetting process in a more systematic manner, both through a recursive training technique that implements forgetting in a more controlled manner and an ensemble learning technique where each member of the ensemble represents the engine's understanding over a certain period of time. Both of these techniques were integrated into a cognitive radio engine proof-of-concept, and were delivered to the SDR platform on the International Space Station. The results were then compared to the results from the original proof-of-concept. Through comparison, the ensemble learning technique showed promise when comparing performance between training techniques during different communication channel contexts.