The Synthetic GNSS Meta-signal approach at new extent: The dynamic challenge, theorical proposal and technical results for Alt-BOC and ACE-BOC signals

Modern global navigation satellite systems (GNSSs) use advanced signal modulations such as the Galileo Alt-BOC and the BDS-3 ACE-BOC. Full processing of these signals for mass market devices requires receiver front-ends with large bandwidths and significant computational resources. An alternative method to receive these signals is the synthetic Meta-signal reconstruction approach, which operates at the measurement level and requires limited additional resources. This approach generates wideband GNSS measurements from side-band observations and delivers high-accuracy pseudorange (PSR) measurements by combining side-band code measurements with side-band wide-lane linear carrier phase (CP) combinations. While effective in static conditions, the synthetic meta-signal usability in dynamic conditions faces challenges due to cycle slips and loss of lock caused by scattering and other impairments. A novel technique is introduced in the article to continue delivering high-accuracy PSRs when CP is lost, relying on predicted contributions from previous high-accuracy PSRs and low-accuracy sideband information. This technique ensures continued high-accuracy PSR generation in urban canyons and short obscurations, leading to significant performance gains in dynamic scenarios and improved overall receiver performance. It thereby extends the applicability of the synthetic meta-signal approach to new levels and significantly increases its usability.