Satellite communications are critical to support the broadcasting industry and satellite communication providers are exploring the use of the extra high frequency (EHF) bands due to the increasing consumer demand for high data rate services. The performance of EHF satellite system is severely degraded by strong oscillator phase noise. Golden Angle Modulation (GAM) is a novel modulation scheme and provides better code modulation (CM) capacity than APSK. However, bit mapping of GAM has rarely been studied in the literature. In this paper, we propose a strategy for the bit mapping of GAM named GB-GAM (U-V). Simulation results show that GB-GAM (U-V) performs the best with strong phase noise. Compared with APSK, bit mappings designed by our strategy perform better in different cases and show the superior performance and robustness of GAM in the presence of phase noise. It can be seen that GAM could be considered as a promising technology for satellite communications in the EHF bands.