Galileo's Problem with PRS or What's in a Phase?

Figure 1

Simplified GNSS channel from transmitter to receiver transmitting two possible phases of sub-carrier to code for BOC(15, 2.5). Example code (magenta); cosine option (red); sine option (blue). Code rate 𝑓_𝐶 = 2.5 × 1.023 MHz sub-carrier frequency 𝑓_𝑆 = 15 × 1.023 MHz.