PN code tracking aided by GMSK signal algorithm based on GMSK+PN-FH
Songming Liu, Shixun Luo · 2022
GMSK+PN-FH has the development potential with the advantages of constant envelope, high spectral efficiency, high precision ranging and time synchronization, and anti- interference. It is a research hotspot in the field of covert anti- interference communication ranging integration system. GMSK+PN-FH requires accurate carrier synchronization. However, the existing carrier tracking loop assisted code tracking loop algorithm cannot achieve accurate carrier synchronization at high hop speed, which limits the improvement of hop speed and the ability of covert anti-interference. This paper proposes an algorithm named PN code tracking aided by GMSK signal algorithm based on GMSK+PN-FH, which sacrifices 25% of the communication efficiency and can work stably in a high-speed frequency-hopping (FH) system where one period PN chip is transmitted in four FH time slots, and the mean square error of the code tracking error is less than 0.0419 chip.