Galileo E1 and E5a Link-Level Performances in Single and Multipath Channels

Abstract

The emerging global satellites system Galileo has gained much public interest regarding location and positioning services. Two new modulations, Composite Binary Offset Carrier (CBOC) and Alternate Binary Offset Carrier (AltBOC) will be used in the E1 and E5 band in the Galileo Open service (OS), respectively. The AltBOC modulation has the advantage that the E5a and E5b band can be processed independently as traditional BPSK signal or together, leading to a better tracking performance in terms of noise and multipath mitigation at the cost of a large front-end bandwidth and increased complexity. The theoretical study of the signal tracking in each band, separately, has been addressed before, but a comparison between the E1 and E5 signals and validation through the simulation with the realistic channel are still lacking in the current literature. In this paper, the tracking performance between the Galileo E5a signal and Galileo E1 signal with different noise level and multipath profiles are compared by using the Simulink-based simulators built within our department at Tampere University of Technology. The simulation results are shown in terms of Root Mean Square Error (RMSE). The probability distribution of code tracking error is also investigated.