Sampling frequency impact on false lock of high order BOC signals in open-loop processing

Abstract

The modernized GNSS systems introduced the idea of BOC signals, which provide better tracking accuracy than BPSK signals at the cost of having side lobes in the autocorrelation function. In closed-loop processing, or tracking, the presence of side lobes can origin false locks, thus making the ranging estimate to be biased by several meters. The overall position, velocity and time solution can then be severely distorted in that situation. The false lock in high order BOC signals is a well known problem and several state-of-the-art techniques address it. This article evaluates the problem from an open-loop perspective. In particular, the impact of the sampling frequency on the probability of false lock is examined.