GPS/Galileo Multipath Mitigation Using the First Side Peak of Double Delta Correlator

摘要

In this paper, we propose an efficient scheme for the Line of Sight (LOS) delay estimation in satellite telecommunications. It aims to reduce errors caused by the Multipath (MP) fading channels in Global Navigation Satellite System (GNSS) such as Global Positioning System (GPS) and future Galileo. The scheme is based on the use of first side peaks of Double Delta Correlator (DDC) in combination with Savitzky-Golay Filter (SGF). The proposed scheme is called “Enhanced DDC (EDDC)”. The DDC technique, like High Resolution Correlator (HRC) and Strobe Correlator (SC), uses the central peak of the Correlation Function (CF) for the LOS delay estimation. As a result, it enables to deal with the medium-delay MP. Yet, it presents a greater sensitivity to the noise and to the long-delay MP that we propose to mitigate, respectively, with the use of SGF and the measure of the first side peak (instead of the central). The obtained results show that our proposed scheme gives better performances over DDC scheme. In fact, it shows a significant error reduction caused by the presence of long-delay MP signals (up to 90%) compared to that of the DDC scheme.