As the only priority frequency band for navigation services except L protected by ITU, the Cn band could provide navigation services to solve problems of spectrum congestion and vulnerability to interference faced in L using global navigation satellite systems. However, Cn band navigation still faces some problems such as limited-bandwidth and link uncertainty. To solve these problems, an orthogonal MSK signal is designed in this paper under Cn limited bandwidth constraint. The analysis results show that although it’s ranging performance of narrow correlation spacing has been deteriorated, the performance of wide correlation spacing has been improved, and it can reduce 98.7% power interference to adjacent radio astronomy band. On the other hand, the Cn band navigation signal test based on the satellite-to-ground link is carried out in this paper. The test results show that the trend of designed signals’ ranging performance is consistent with the simulation results and its rain attenuation is 0.5–1dB.