Analysis of Side Lobes Cancellation Methods for BOCcos(n, m) signals

Abstract

The next generation of Global Navigation Satellite Systems (GNSS) are implementing Binary Offset Carrier (BOC) modulation. These signals were expected to provide not only better precision in the estimation of the signal's delay and phase but also more robustness to multipath effects. The advantage of BOC signals is that the main lobe of the correlation is very narrow although they present side lobes. For high-order signals, the amplitude of the side lobes can be similar to the amplitude of the main one or even exceed it under specific scenarios. One kind of techniques that mitigates the ambiguity problem is called Side Lobes Cancellation (SLC). The idea of these methods is to see the BOC signal as a sum of different sub-signals which are orthogonal in time domain. These techniques compute the cross-correlation function between the incoming BOC signal and the sub-signals obtaining sub-correlations functions and then they combine them in order to achieve an unambiguous correlation. Although, this kind of techniques are able to work with any kind of BOC signals, there are very few papers that deal with high-order BOC signals or even with BOCcos signals. This paper presents a thorough study about Side Lobes Cancellation methods (SLC), with special emphasis on high-order BOC signals. The main purpose of this paper is to demonstrate the behaviour on Side lobe Cancellation methods (SLC) for high-order BOCcos signals.