A new signal modulation for GNSS

AltBOC(15,10) is the baseline of COMPASS B2 signal modulation and TD-AltBOC is presented recent years. However, AltBOC modulation has drawbacks such as low multiplexing efficiency and great receiver complexity, the frequency utilization rate of TD-AltBOC is low. This paper presents a new modulation type named PS-AltBOC (Phase Shifted AltBOC) with constant envelope based on the standard AltBOC modulation. The detail principle of PS-AltBOC is presented and the math expression of PS-AltBOC is derived. Finally the performances of PSD (Power Spectrum Density), ranging and multipath tracking performance, side-band losses are compared with the AltBOC modulation. Analysis results show that PS-AltBOC has similar spectrum characteristics, ranging and multipath tracking performance with the AltBOC, and the out-of-side loss is lower than AltBOC. The tracking performance is also better on the condition that the frontend band is around 90 MHz. PS-AltBOC could be a feasible modulation for COMPASS B2 navigation signal.