Software Radio Based ASM Signal Ranging Delay Measurement System

In contemporary society, where Global Navigation Satellite Systems (GNSS) are utilised extensively, their inherent fragility gives rise to potential hazards with respect to the safety of ship navigation. In order to address this issue, the present study focuses on an ASM signal delay measurement system based on software defined radio peripherals. The system comprises two distinct components: a transmitting end and a receiving end. At the transmitting end, a signal generator, a first time-frequency synchronisation device, and a VHF transmitting antenna are employed to transmit ASM signals comprising dual Barker 13 code training sequences. At the receiving end, signals are received via software-defined radio equipment, a second time-frequency synchronisation device, a computing host, and a VHF receiving antenna. Utilising sliding correlation algorithms enables accurate time delay estimation. The present study leverages the high performance and low cost advantages of the universal software-defined radio peripheral USRP, fully utilises the good autocorrelation of ASM signals, effectively improves the accuracy of signal transmission delay measurement, and provides a reliable technical means to ensure the safety of ship navigation. The practical application of this subject is of significant importance, and there are wide prospects for its promotion and application.