Use-case analysis of the BOC/CBOC modulations in GIOVE-B E1 signal

Abstract

In the past decade, the current and envisaged GNSS systems have seen major developments, both in terms of interoperability and compatibility, as well as accuracy, performance, and availability. In particular, the emergence of Galileo and the evolution of other Global Navigation Satellite Systems (GNSS) have not only brought forth new opportunities and applications, but also new signal structures. The underlying studies on Binary Offset Carrier (BOC) and Multiplexed Binary Offset Carrier (MBOC) modulations, signal properties, tracking methods, and general performances, have theoretically confirmed and supported the benefits of future GNSS signals. As a result of this diversity of signals, the Galileo E1-L1 signal modulation is an implementation of MBOC, the Composite Binary Offset Carrier modulation - CBOC(6,1,1/11). Receiver designers will have to decide and trade-off for tracking the Galileo E1-L1 signal either as CBOC(6,1,1/11) or BOC(1,1), taking into account the benefits and costs of each solution. This study presents the results obtained with processing CBOC data in two conditions: first, using a simulator to generate a multipath environment, and second, using real data from GIOVE-B satellite collected at GMV's rooftop. These data sets were processed using the NUSAR platform to produce the observables.