Abstract: The signals of global navigation satellite system of China must obey many constraints, and should  be coordinated with other navigation signals as well. The service type, carrier frequency, modulation scheme and spreading codes are essential for the coordination. The signal structure and parameters of COMPASS excerpted from the reference assumptions document（RAD）were presented. The correlation performances of the spreading codes of the COMPASS open signals were consistent with  that of GPS. Base on the signal structure and basic parameters of the RADs, COMPASS and GPS,   the L band frequency coordination  was completed in accordance with the frames established by ITU in September, 2010.

Key words: Signal system, Modulation scheme, Code correlation, Spreading codes, COMPASS