An Interference Impact Assessment Model for GNSS Signals

The significant growth of the number of applications based on position information and navigation technology is one of the reasons that pushed the investigation of methods for evaluating the signal robustness and reliability. Among the several aspects to be investigated when comparing different signals performance, the robustness to multipath effects and to external interference (i.e., radiofrequency signals generated by other transmission systems) have to be accomplished. When dealing with the interference issue, one of the main problems is the large number of unknown parameters needed to model the signal (modulation type, spectral bandwidth, etc). Aim of this paper is the definition of new families of curves, called Interference Error Envelope (IEE), able to assess the impact of the interferer on different GNSS signals. Continuous Wave (CW) and Wide Band (WB) interference signals are considered in order to obtain IEE and Interference Running Average (IRA) curves for different modulation signals like Multiplexed Binary Offset Carrier (MBOC) formats. Their performances in terms of interference robustness will be evaluated and compared with those of the well known modulations (Binary Phase Shift Keying, BPSK, or Binary Offset Carrier, BOC(1,1)).