Traction spoofing is an important component of Global Navigation Satellite System (GNSS) intermediate attacks, and the traction scheme directly determines the concealment of spoofing. However, spoofing via conventional traction strategies can be easily detected using Time of Arrival (TOA) and power detection. Based on a BPSK-modulated signal, a novel traction strategy using traction code is proposed to suppress part of the authentication signal and form an ideal correlation peak. This strategy was modeled and simulated to verify its theoretical feasibility. Effective spoofing data were generated based on the signal generation software to verify the spoofing effect with the reception of the software receiver. It can be inferred that no significant distortion occurred throughout the traction process, and the value range of the traction speed was expanded. The received results in different scenarios demonstrated that the observations’ Root-Mean-Square Error (RMSE) percentage change in the proposed strategy is significantly better than those of conventional strategies. A Ratio Test was also performed, verifying that the strategy can bypass Signal Quality Monitoring (SQM) detection. Meanwhile, the proposed strategy remained effective when the $\mathrm{C}/{\mathrm{N}}_0$ increased to 60 dBHz. In summary, the proposed strategy exhibits destructiveness, concealment, and adaptability on the battlefield.

A distinctive feature of modern Global Navigation Satellite System (GNSS) signals is that they transmit multiple signal components at the same carrier frequencies. The idea of joints across the signal channels from the same carrier frequency and even across different frequencies has been presented in many studies for tracking purposes. Carrier joint tracking is required on the premise that the frequency and phase relationship between signals are nominal values, and the bias of carrier characteristics between signals is drowned in noise as the signal reaches the ground, which requires high-gain receiving equipment to restore the original signal. The space signal-quality monitoring and evaluation system built by the National Timing Center of the Chinese Academy of Sciences is based on a 40 m dish antenna, which can automatically track a single satellite and achieve a high-fidelity reception of navigation signals to a certain extent, realizing fine signal quality monitoring (SQM) of GNSS satellites. Based on this platform, we discuss four types of time distributions of the combined signals among different signal components and provide a method to estimate the carrier characteristic bias between GNSS signals. We derived the correction method of carrier characteristic bias in the joint reception by the joint tracking mathematical model. Under the conditions of narrow correlation and unobstructed case, the carrier characteristic deviation does not vary significantly with the correlator interval and the satellite elevation angle. Based on the results of stability analysis, it is recommended that the receivers should update the carrier frequency bias correction number of the intra-frequency signal and carrier phase bias correction number of the intra-frequency signal monthly. The carrier phase deviation correction number of the inter-frequency signal is performed daily. The measured data from satellites show that the phase accumulation error of the joint tracking carrier loop can be eliminated to achieve long-term stable tracking after frequency bias correction. After the carrier phase bias correction, the joint positioning accuracy of the B2a and B2b signals was improved by 0.81%, and those of the B1C, L1C, E1C, and B2a signals were improved by 0.35%, 0.04%, 0.20%, and 0.11%, respectively. The positioning accuracy improvement effect of inter-frequency signals was greater than that of intra-frequency signals after carrier phase correction.

The widespread 5G base stations can be potential jammers for the vulnerable BeiDou B1I receivers due to its low power. Therefore, a novel analytical model is derived for the 5G signal to evaluate its impact on acquisition performance under three decision methods. The good agreement between the Monte Carlo method (MCM) through software defined receiver (SDR) and the derived expressions validates the effectiveness of the proposed algorithm. It can be found that the receivers exhibit varied responses for different 5G waveforms and decision strategies. The receiver also shows the least endurances for some kind of 5G waveforms, however, this kind of adverse effect can be cancelled by a reduced interference signal ratio (ISR), an increased integration time or a larger accumulation times.

The Quasi-Zenith Satellite System (QZSS) plays a pivotal role in providing vital navigation, positioning, timing, and signal authentication services, particularly through its L5 signal. Despite its importance, research on the performance of the L5 signal remains relatively limited. This study presents an empirical analysis of the L5 signal, identifying the distinct amplitude and phase distortion phenomena within its constellation diagram. Simulation methods are employed to replicate these observed anomalies, revealing that the L5 signal is significantly impacted by in-band inter-signal interference and the multipath effect at the satellite end of the star. A quantitative analysis is performed to investigate the underlying causes of these distortions, offering a deeper understanding of the factors contributing to the observed signal irregularities. The findings provide essential data and theoretical insights, contributing to the optimization of the QZSS signal quality and performance.