Wavelet-based Interference Perception and Reduction Approach for NB and CW RFI on NavIC S-band Signals

Abstract

Any Global Navigation Satellite System (GNSS) is particularly susceptible to accidental and malicious Radio Frequency Interference (RFI). The objective of the work is to simulate Narrow-Band (NB) and Continuous-Wave (CW) RFI on NavIC signal and analyze the effects of these RFI under the performance of the proposed Wavelet-based Interference Perception and Reduction (IPR) algorithm. The advantage of the Wavelet Packet Decomposition (WPD) based proposed algorithm is to smartly identify the interfered frequency bands and apply threshold only to these identified frequency bands. Here, the simulation results for NB and CW RFI are carried out, and it can be used as a reference for the real-time RFI effect. The main focus is to observe the characteristics of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$C/N_{0}$</tex> When RFI is equal to or close to the center frequency of the useful signal. From this analysis, it is found that the proposed algorithm gives an approximately 1–3 dB of improvement in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$C/N_{0}$</tex> values, and it provides better perception and reduction of both RFI. The analysis demonstrated that the performance of NavIC systems in the presence of NB and CW RFI could be enhanced significantly through the use of active RFI suppression before the correlation process.