Complex double-binary-offset-carrier modulation for a unitary characterisation of Galileo and GPS signals

Abstract

In this paper we introduce a new class of modulations, the Complex Double Binary-Carrier-Offset (CDBOC) modulation class, which covers most of the modulation types proposed so far for Galileo and GPS signals, namely the binary and quaternary phase shift keying (BPSK/QPSK), sine BOC (SinBOC), cosine BOC (CosBOC) and alternate BOC (AltBOC) modulations. At the same time, CDBOC class provides a more general framework, with potential for new applications of wide-band CDMA systems and/or future satellite navigation systems. We introduce the theoretical derivations of the Power Spectral Density (PSD) and the Auto-Correlation Function (ACF) of the CDBOC-modulated signals, and we compare the theoretical analysis with the results obtained via simulations. The advantage of our method in the context of Galileo and GPS signals is its simplicity and the fact that it provides unified analytical formulas for most of the existent GPS/Galileo signals.