How can GNSS interference be mitigated in autonomous vehicles?

1 Signal quality monitoring

One way to detect and mitigate GNSS interference is to monitor the quality of the received signals, such as the carrier-to-noise ratio (C/N0), the signal strength, the phase, and the frequency. By comparing the expected and observed signal characteristics, autonomous vehicles can identify anomalies and potential sources of interference. For example, a sudden drop in C/N0 or a shift in frequency may indicate a jamming attack, while a mismatch in phase or location may indicate a spoofing attack. Signal quality monitoring can help autonomous vehicles to reject or correct corrupted signals, switch to alternative sources of navigation, or alert the authorities.

2 Antenna array processing

Another way to mitigate GNSS interference is to use antenna array processing, which involves combining multiple antennas to form a directional beam towards the desired satellite signals and suppress the unwanted interference signals. Antenna array processing can enhance the signal-to-interference-plus-noise ratio (SINR) and improve the accuracy and reliability of GNSS positioning. However, antenna array processing requires complex hardware and software, such as adaptive beamforming algorithms, calibration methods, and synchronization mechanisms. Antenna array processing also faces challenges in dealing with dynamic environments, multiple interference sources, and low signal-to-noise ratio (SNR) scenarios.

3 Cooperative positioning

A third way to mitigate GNSS interference is to use cooperative positioning, which leverages the communication and information sharing among autonomous vehicles and infrastructure to enhance the GNSS positioning. Cooperative positioning can provide redundancy, diversity, and robustness to GNSS positioning, as autonomous vehicles can exchange their GNSS measurements, positions, velocities, and other relevant data with each other or with nearby base stations. Cooperative positioning can also exploit the spatial and temporal correlation of GNSS interference to estimate and compensate for its effects. However, cooperative positioning requires reliable and secure communication links, common reference frames, data fusion algorithms, and privacy protection mechanisms.