Solving the correlation peak ambiguity of BOC signals

Abstract

The Binary Offset Carrier (BOC) modulation is planned for future GNSS signal. This modulation improves positioning accuracy and enhances multipath rejection. However this modulation brings some drawbacks resulting from the representation of the autocorrelation function (ACF). The ACF presents multiple peak bringing about risk of false acquisition or false tracking, especially in a noisy environment. This paper presents a new efficient alternative technique allowing to acquire BOC signals unambiguously. It is based on a non linear quadratic operator called Teager-Kaiser (TK) operator. This TK operator has shown a high efficiency to mitigate multipath on classical C/A GPS signals and can be very simply implemented [7]. In this study, we analyze the effectiveness of this operator to exploit the structure of the correlation function between the received signal and the reference BOC signal. So it is shown that the operator can be defined as an unambiguous solution for BOC acquisition. It is also adapted for DLL loop monitoring by detecting false peak tracking.