The current research on the global navigation satellite system (GNSS) has shifted to focus on providing secure and reliable services, rather than high-precision positioning services. Deception jamming has emerged as a major threat to GNSS security applications due to its advantages such as concealment. For security signals not publicly available in the spread spectrum code sequence, simple deception methods do not suffice to implement effective deception. In response, the security code estimation and replay (SCER) attack was proposed. However, the impact of the spread spectrum code estimation error on the receiver and SCER attack effect is still unclear. This paper is based on the SCER attack and deception signal receiving model, constructs a receiver tracking loop analysis model and carrier to noise ratio (CNR) estimation model based on spread spectrum code error, and analyzes the impact of spread spectrum code error on the receiver tracking loop and CNR. Based on the experimental results and discussion, some conclusions have been drawn. Firstly, spread spectrum code error will cause correlation peak distortion and a decrease in CNR. Secondly, to achieve effective deception, the spread spectrum code error cannot be increased indefinitely and an upper bound exists, which ranges from about 41%, depending on the deceived receiver acquisition strategy. Thirdly, when the spread spectrum code error rate is less than the upper bound, the mean square error of the code phase measurement is less than 0.02 chip, which is on the same order of magnitude as caused by thermal noise. As such, it can be approximately assumed that the code tracking deviation caused by spread spectrum code error has minimal impact on the SCER attack. Although reducing the receiving terminal gain of the SCER attack will lead to an increase in the spread spectrum code estimation error, it is possible to increase the transmitting terminal gain of the SCER attack to maintain the same CNR of the deception signal and deception effect, greatly reducing the cost of the deception.

Inter‐satellite link (ISL) will play an increasingly important role in the next generation of global navigation satellite system (GNSS). The inter‐satellite distances in the GNSS vary greatly, resulting in a power loss difference of as much as 20 db. However, there are no reports on promotion of spectral efficiency in inter‐satellite channels at present. In this study, the authors propose an efficient utilisation of the adaptive modulation and coding (AMC) scheme for ISLs in the GNSS. A novel method, based on inter‐satellite distance, is presented for choosing the modulation and coding scheme (MCS). The proposed method provides a convenient way to estimate signal‐to‐noise ratio of the ISLs in GNSS. This AMC technique is implemented according to two different algorithms. One is the target bit error rate (BER) algorithm based on inter‐satellite distance, aimed at keeping the BER below a target limit. The other is the maximum throughput algorithm based on inter‐satellite distance, aimed at maximising the data throughput. In cases where the inter‐satellite distance is short, simulation results show that, under the premise of the same transmission power, the throughput of two proposed AMC schemes is nearly six times that of a fixed MCS.

The Global Navigation Satellite System (GNSS) has been applied to all aspects of social livelihood and military applications and has become an important part of national infrastructure construction. However, due to the vulnerability of GNSS, satellite navigation jamming technology can pose a serious threat to GNSS security applications, and this has become a research hotspot in the field of navigation countermeasures. In this paper, satellite navigation jamming technologies are divided into suppression jamming and deception jamming, and the research status of satellite navigation suppression jamming and deception jamming technologies are sorted by three aspects: jamming technology classification, jamming efficiency evaluation, and jamming source deployment. Finally, the future development trend of satellite navigation jamming technology is summarized.

The adaptive beamforming algorithm can realize interference suppression and navigation signal enhancement, and has been widely used. However, achieving high-precision real-time estimation of the direction of arrival (DOA) parameters of navigation signals in strong-interference scenarios with low complexity is still a challenge. In this paper, a blind adaptive beamforming algorithm for a Global Navigation Satellite System (GNSS) array receiver based on direction lock loop is proposed without using the prior information of the DOA parameter. The direction lock loop is used for DOA tracking and estimation after interference suppression, which uses the spatial correlation of the array beam pattern to construct a closed direction-tracking loop. The DOA estimation value is adjusted in real time based on the loop errors. A blind beamformer is constructed using the DOA estimation results to provide gain by forming a beam in the satellite direction. This method improves the accuracy and dynamic adaptability of DOA estimation while significantly reducing the computational complexity. The theoretical analysis and simulation results verify the effectiveness of the proposed algorithm.