Adaptive Interference Rejection Filtering in On-Board Direct-Sequence / Spread-Spectrum Transponder for TT&C Applications: Analysis, Simulation & Breadboard Test Results

Next generation of on-board Telemetry, Tracking and Command (TT&C) equipment for secure communications shall adopt robust anti-jamming approaches allowing to cope with jammer-to-signal power ratios higher than 50 dB. However classical Direct Sequence/Spread-Spectrum (DS/SS) techniques, due to their limited processing gain, do not necessarily provide enough jammer rejection to ensure reliable communication. In these cases, use of an adaptive filter to remove some jammer energy prior to correlation can significantly improve system performance. This paper offers a complete overview of adaptive filtering approaches as successfully experimented by Thales Alenia Space - Italy (TAS-I) for the Spread-Spectrum Transponder (SST) line.