Analytical Performance of GNSS Receivers using Interference Mitigation Techniques

The interest in using Global Navigation Satellite Systems (GNSS) for applications with demanding requirements for security and integrity, such as civil aviation, has focused attention on the robustness of GNSS receivers against external interferences. This issue can be even more relevant considering that GNSS modernization will share new spectral bands with other systems already in use. Some recent works address the problem through the use of an interference mitigation technique (IMT) in the receiver. Here, the focus is on theoretically predicting the time of arrival (TOA) estimation error of such receivers which incorporate either of the two most extended IMTs: time-domain blanking (TDB) and frequency-domain adaptive filtering (FDAF). These techniques are currently working and being used. The theoretical expressions provided herein are suitable for receivers based on a code-tracking loop that uses an early-late processor and are accurate for small-error conditions. Besides, the performance analysis is particularized for periodic-pulsed interferences for TDB, while it is particularized for narrowband and linear frequency modulated interferences for FDAF. The most relevant conclusion is that both techniques are able to largely maintain the performance of the receiver in the presence of the respective interferences considered. These results are also validated with computer simulations.