Ground Based Augmentation System (GBAS) is an enabling technology for GNSS based precision approach. However, GBAS is vulnerable to radio frequency interference, so GNSS interference detection and mitigation is essential for safe aircraft operation based on GBAS. In this paper, a GNSS interference simulator is designed based on previously developed GPS L1 software simulator. The interference simulator can generate user specified interferences repeatedly, so it can be used for interference signal characterization and detection algorithm research. The simulator gets signal parameters from a user and generates GPS L1 signal, noise and interference signals. The generated signals are processed by band pass filter, AGC, and ADC module and saved in a binary file. The simulator can generate single-tone continuous wave interference, swept continuous wave interference and band limited white Gaussian noise. The simulated signal data was verified by theoretical evaluation of signal spectrum and used for interference effect assessment and interference detection and mitigation algorithm research. This simulation environment allows rapid modification and tuning of parameters during algorithm development.

Keywords: GNSS signal simulator, interference simulator, MATLAB SIMULINK