北斗三号B1频点卫星导航信号的调制复用及实际接收性能

导航信号结构是卫星导航系统的核心技术之一,也是我国北斗三号卫星导航系统独立建设、自主运行的标志.本文分析了北斗三号B1频点卫星导航信号设计的需求与挑战,详细介绍了为满足北斗三号新一代导航信号性能提升、多样化接收以及与其他导航系统兼容与互操作等方面的迫切需求,我们为北斗三号主用信号B1C提出了一种新型的正交复用二进制载波偏移(Quadrature Multiplexed Binary Offset Carrier,QMBOC)调制技术,以及为解决北斗三号B1频点新旧两代和军民两类导航信号并存的重大技术难题,提出了一种通用的多频多分量导航信号恒包络复用(CEMIC)技术,并通过对北斗三号组网卫星实际播发的信号接收处理与分析,验证了新一代B1频点信号的先进性能.QMBOC调制和CEMIC复用构成了北斗三号B1信号的核心结构,在很大程度上决定了信号的时频域特性、接收性能及发射效率,目前已经部署在北斗三号所有的组网卫星上并开始向全球提供服务,成为北斗三号赶超世界先进水平的重要特征.

BDS-3 B1 signal modulation and multiplexing techniques with receiving performance

The navigation signal structure is one of the primary technologies of the satellite navigation system and also a symbol of the BeiDou global navigation satellite system(BDS-3).In this study,the design requirement and challenges of the BDS-3 B1 band signals are first analyzed.After that,the principle and development of an innovative modulation technique,namely Quadrature Multiplexed Binary Offset Carrier(QMBOC)modulation technique,and a generalized multifrequency multi-component navigation signal constant envelope multiplexing technique,i.e.,Constant Envelope Multiplexing via Intermodulation Construction(CEMIC),are introduced in detail.Also,the advanced performance of the new-generation B1 signal is verified through the reception and analysis of the signal transmitted by the BDS-3 satellites.The results from the performance analysis of the signal show that the QMBOC modulation can satisfy the requirements needed for the performance improvement of the next-generation navigation signal,diversified reception modes,as well as the compatibility and interoperability with other navigation systems.Also,the results reveal that the CEMIC multiplexing technique can solve the B1 multiplexing issue caused by the coexistence of new and legacy signals,as well as open and authorized signals.The QMBOC modulation and CEMIC multiplexing technique form the core of the BDS B1 signal scheme and,to a great extent,determine the time-frequency domain characteristics,reception performance,and the transmission efficiency of the signals,which embodies both the innovation of these techniques and their value in engineering application.Presently,these techniques have been applied to all BDS-3 satellites and provide services to the world,which becomes a major hallmark of BDS-3 surpassing the advanced level of the world.