When 5G NTN Meets GNSS: Tracking GNSS Signals under Overlaid 5G Waveforms

TL;DR

This study demonstrates that GNSS signals can be reliably tracked and demodulated even when overlaid with 5G waveforms, enabling joint communication and positioning with minimal receiver modifications.

Contribution

It provides the first quantitative analysis of GNSS performance under hybrid 5G waveform interference, showing feasibility for joint communication and positioning.

Findings

Reliable demodulation across wide SINR ranges for low and medium dynamics

High dynamics impose strict lock limits on GNSS tracking

Feasibility of JCAP with near-legacy GNSS chipsets

Abstract

Global Navigation Satellite Systems (GNSS) provide the backbone of Positioning, Navigation, and Timing (PNT) but remain vulnerable to interference. Low Earth Orbit (LEO) constellations within Fifth-Generation (5G) Non-Terrestrial Networks (NTN) can enhance resilience by jointly supporting communication and navigation. This paper presents the first quantitative analysis of GNSS tracking and navigation message demodulation under a hybrid waveform where a low-power Direct-Sequence Spread Spectrum (DSSS) component is overlaid on an Orthogonal Frequency-Division Multiplexing (OFDM) 5G downlink. We evaluate a minimally modified GNSS receiver that tracks a legacy Global Positioning System (GPS) L1 Coarse/Acquisition (C/A) overlay aligned with 5G frames while treating the 5G waveform as structured interference. Using Monte Carlo simulations under realistic LEO Doppler dynamics, we analyze the Bit Error Rate (BER) of GPS L1 C/A navigation bits and the subframe decoding probability versus Signalto- Interference-plus-Noise Ratio (SINR) for multiple Signalto- Interference Ratios (SIR) and dynamic classes. Results show reliable demodulation across wide SINR ranges for low and medium dynamics, whereas high dynamics impose strict lock limits. These findings confirm the feasibility of Joint Communication and Positioning (JCAP) using a near-legacy GNSS chipset with minimal receiver modifications.