TITLE:
Interference Detection and Suppression Based on Time-Frequency Analysis
AUTHORS:
Haijun Huang, Kewen Sun
KEYWORDS:
RFI, GNSS, Sweep Interference, FrFT, STFT, WVD, Threshold
JOURNAL NAME:
Advances in Aerospace Science and Technology,
Vol.7 No.2,
May
18,
2022
ABSTRACT: Radio
frequency interference (RFI) is greatly harmful to Global Navigation Satellite System (GNSS)
receivers. Sweep interference is one of the
RFI for the GNSS receivers, which can degrade the performance of GNSS receivers seriously. In this paper, the Fractional Fourier Transform
(FrFT) of time-frequency analysis is proposed in the GNSS interference
detection and suppression. The FrFT method is tested for detecting and
suppressing sweep interference, which is generated by a GNSS jammer. In the simulation
experiment, the GNSS signal affected by sweep frequency interference is
successfully captured after interference suppression by using the proposed
method, which shows its effectiveness. The interference detection performance of the FrFT method
is compared with the conventional techniques such as Short-Time Fourier
transform (STFT) and Wigner-Ville
distribution (WVD). The detection performance is improved by about a least one
order of magnitude. In the aspect of interference suppression, a threshold
method based on detection probability is proposed, and the performance of the
proposed threshold method is compared with the conventional threshold methods.
In the result, the interference tolerance is increased by 5 dB compared with the mean
threshold method, and by 9 dB
compared with the fixed threshold.