Joint Acquisition and Satellite Identification with Search Space Reduction in Opportunistic LEO-PNT

초록

This paper proposes a joint acquisition and satellite identification method for opportunistic low earth orbit (LEO) positioning, navigation, and timing (PNT) with Starlink pilot-tone signal. Since the pilot tone power of LEO communication satellites is considerably low, noncoherent integration over a long observation window is required for signal acquisition, yet the Doppler rate induced by LEO satellite mobility must be simultaneously compensated to maximize the integration gain. Existing methods perform exhaustive grid search-based acquisition with satellite identification separately, resulting in high computational complexity. The proposed method leverages predicted Doppler rates from known satellite orbits to reduce the search space, and employs a hierarchical candidate selection with a fine grid search to jointly achieve acquisition and satellite identification within a unified framework. Simulation and experimental results using a USRP testbed validate the effectiveness of the proposed method in terms of both identification accuracy and computational efficiency.

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