基于码片幅度调制的导航信号扩频码认证方法

信号认证是满足全球卫星导航系统(GNSS)民用信号安全性需求的关键，相比于导航电文认证(NMA),扩频码认证(SCA)具有更强的安全性。为了在实现SCA的同时不对非认证用户造成影响，提出了一种基于码片幅度调制(CAM)的导航信号SCA方法，对民用信号的扩频码的码片幅度进行了调制，实现了在扩频码层面的认证特征的引入。为了验证所提方法的有效性，采用理论和仿真分析，与GPS L1C采用的Chimera SCA方法进行了比较。结果表明，所提方法在检测性能方面提升了2.55～2.78 dB。研究成果可为下一代高安全卫星导航信号的设计提供支持。

Spreading code authentication method for GNSS signals based on chip-level amplitude modulation

Signal authentication is the key technique to meet the security requirement of next-generation GNSS civil signals.Compared with navigation message authentication(NMA),the spreading code authentication(SCA)can achieve greater security.To avoid the influence on the non-authentication users,the spreading code authentication method based on chip-level amplitude modulation(CAM-SCA)was developed.The proposed CAM-SCA method introduced the authentication feature to the chip level of GNSS civil signal by amplitude modulation.To verify the effectiveness of the proposed method,the detection probability was analyzed with the help of theory and simulation,and compared with the Chimera method adopted by GPS L1C signal.The results show that the proposed CAM-SCA method has an improvement of 2.55-2.78dB in terms of detection performance.The research results can provide a reference for the design of the next generation high-security GNSS signal.