Pulse Interference Mitigation Method for BeiDou Receivers Based on Message Randomization
Anning Liu, Honglei Lin, Xiaomei Tang, Gang Ou, Hang Gong · Remote Sensing · 2025
In complex electromagnetic environments, especially those with pulsed interference sources, long-period pulsed interference can repeatedly disrupt the real-time data within navigation messages, preventing receivers from obtaining complete message information and significantly extending the time to first fix (TTFF). To address this problem, the interference mechanism is modeled and analyzed from the perspective of navigation message structure. An anti-interference strategy based on navigation message scrambling is proposed, including two key techniques: random scrambling of subframe order and message interleaving encoding. Simulation and experimental results demonstrate that various pulsed interference patterns, with different periods and duty cycles, can significantly impact TTFF. The subframe scrambling method is effective against interference whose period exceeds the subframe duration but is limited when the period is equal to or shorter than the subframe. In contrast, the interleaving method provides more universal resistance across interference patterns. When both techniques are combined, the overall anti-interference performance is further enhanced. Specifically, for interference patterns with periods longer than the subframe duration, the probability that the receiver fails to achieve positioning across multiple consecutive frames is reduced by at least 50% compared to the case without interference mitigation.