Code Phase Multipath Mitigation by Exploiting the Frequency Diversity in Galileo E5 AltBOC

In heavy multipath scenarios such as urban canyons, the user code phase pseudorange error due to multipath fading can be as high as two meters even for the most sophisticated ranging signals such as Galileo E5 Alternate Binary-Offset-Carrier AltBOC (15,10). In this paper the author introduces methods to mitigate the code phase multipath by exploiting the frequency diversity which is inherent to the AltBOC modulation used in Galileo E5 satellite navigation signals. A detailed analysis of the proposed method - called SCPC (Sideband Carrier Phase Combination) - is provided and its features are discussed. With the help of simulations and the signal collected from satellites, it is shown that the instantaneous code phase multipath error can be reduced to less than half a meter.