An LUT-based Adaptive DPLL for SSV GNSS Receivers

Global Navigation Satellite System (GNSS) receivers suffer from low signal power and high dynamic stress when operating in the Space Service Volume (SSV). Therefore, the dedicated design of receivers for challenging environments is needed. In this paper, a Look-Up Table (LUT)-based adaptive Digital Phase Locked Loop (DPLL) is proposed. It continually adjusts the noise bandwidth of the DPLL properly by continuously measuring current C/N0 and jerk dynamic stress. Because it contains the LUT that has several pre-computed noise bandwidth values, an additional calculation process of the appropriate noise bandwidth value is not needed. Therefore, the receivers simply get the proper noise bandwidth value from LUT in a short time for stable operation. Numerical simulations configured using the moon exploration mission trajectory show that the proposed algorithm maintains tracking of the signal parameters successfully even in the harsh environment simulation scenarios such as the low signal power and/or high dynamics regions, while the conventional fixed noise bandwidth method may lose its lock.