The astrium correlator: Unambiguous tracking of high-rate BOC signals

The processing of Binary Offset Carrier (BOC) signals as transmitted by current Global Navigation Satellite Systems (GNSSs) offers potentially better tracking accuracy and a higher multipath rejection. Yet, the presence of multiple peaks of the BOC signals´ auto-correlation functions (acfs) results in multiple stable but false tracking points in addition to the correct lock position of the correlation function´s main peak. We propose a tracking technique which tracks the subcarrier component of the BOC signal and uses the code component to decide whether or not the correct peak of the correlation function is tracked. The performance is compared to the Bump Jumping and Double Estimator methods in terms of the impact of an emulated front-end filter, continuous wave and chirp interfering signals, forced locks to false peaks, and the multipath envelope. The tests are performed using BOC(1,1) and BOC_cos(15,2.5) signals.