A Candidate for the Galileo L1 OS Optimized Signal

Abstract

On June 26th, 2004, the United States of America and the European Union signed the Agreement on the promotion, provision and use of GALILEO and GPS satellite-based navigation systems and related applications. Among many other topics it was decided to adopt a common baseline signal to be transmitted by both Galileo and the future GPS (L1C) on L1. Although the agreement fixed BOC(1,1) as the baseline for both Galileo L1 Open Service and GPS future L1C signals, it left the door open at the same time for a possible optimization of that signal considering the overall framework conditions of the agreement. This paper is discussing possible candidates for the L1 OS optimized signal and analyses their performance with respect to the baseline BOC(1,1) signal. It is shown that a sophisticated signal may be created which allows users on the one side still to use the baseline BOC(1,1) whereas the high-precision user may track the new optimized signal achieving an improvement of more than 40 % already with a limited bandwidth of 12 MHz.