Verification of Signal Acquisition and Tracking on a LEO PNT Software Receiver

Min Yong Choi, Jinseok Kim, Hung Seok Seo, Young Baek Kim*, Joshua Richards, Matteo Gala, Thyagaraja Marathe

Low Earth Orbit (LEO) satellites are emerging as a next-generation Positioning, Navigation, and Timing (PNT) system due to their high signal power and rapid orbital period. This paper generates digital intermediate frequency (IF) signals identical to the Pulsar navigation signal structure, based on the Interface Control Document (ICD) from Xona Space Systems. A tracking loop filter was modelled using the generated signal, and a Software Defined Receiver (SDR) was implemented based on this model to evaluate signal acquisition and tracking performance. Signal acquisition and tracking parameters were configured to accommodate the high relative velocity and Doppler frequency variation of LEO satellites, and effective signal processing was verified. This work suggests a development direction for future hardware receivers in LEO-based PNT systems.

Keywords: LEO PNT, SDR, signal acquisition and tracking, parameters