伪码调相传输理论及其卫星导航/通信一体化构建方法

Aiming at the problem that a unified signal system cannot realize high precision positioning and high speed data transmission simultaneously in satellite navigation/communication integration system, this project proposed a PN-code phase modulation transmission technology. A pilot channel and a data channel are introduced in this technology, which are distinguished code division multiplexing. The synchronization function is provided by the pilot channel. Thereby the synchronization function of the data channel is released. Thus, the phase of the pseudo random code can be used as the carrier of information. The technology can significantly improve the satellite data transmission rate and maintain the original positioning accuracy under the premise of minimizing the change of original GNSS signal. Therefore, the satellite navigation/communication integration system based on this technology has the following advantages: signal system unified, high positioning accuracy, high data transmission rate, backward navigation function and easy to promote. The main research contents of the project include: the mathematical model establishment of PN-code phase modulation transmission mechanism, the analysis of its system characteristics; analysis of the advantages and limitations of multi - peak PN-code phase modulation strategy; design the modulation and demodulation strategy of PN-code phase modulation, implement the hardware experiment platform; propose the design and selection criteria of PN sequence; and objectively study the construct problems of satellite navigation/communication integration based on PN-code phase modulation. Through the research of this project, the theory and technology system of PN-code phase modulation technology is established to solve the bottleneck problem of satellite navigation/communication integration technology, thereby improve the utilization efficiency of aerospace resources.

针对卫星导航/通信一体化技术中单一信号体制难以同时实现高精度定位和高速率数据传输的问题，项目提出一种伪码调相传输技术，通过码分复用设置导频信道和数据信道，由导频信道提供同步功能，从而将数据信道的同步功能放开，通过其伪随机码相位承载信息。该技术可以在导航信号体制改变较小的前提下，显著提高卫星信号的数据传输速率，并保持原有定位精度。因此，基于该技术的卫星导航/通信一体化系统具有信号体制统一、定位精度高、数据传输速率高、且导航功能向下兼容、易于推广的优势。项目主要研究内容：建立伪码调相传输机理的数学模型，分析其系统特性；分析多峰伪码调相策略的优势与局限；设计伪码调相信号的调制与解调算法，并建立实验平台；提出伪随机序列的设计和选取准则；提出基于伪码调相的卫星导航/通信一体化构建方法。通过本项目的研究，建立伪码调相技术的理论与技术体系，解决卫星导航/通信一体化技术的瓶颈问题，提高航天资源的利用效率。

本项目提出了一种基于伪码调相技术的卫星导航/通信一体化信号体制。该技术通过导航信道为通信信道提供同步能力，通信信道为导航服务提供提速服务，可以实现导航和通信功能的有机结合。研究中对该信号的传输机理和传输性能进行了分析。通过优选码相位的方法，利用互相关干扰增强系统性能。在此基础上，结合模糊化的判决算法，实现了伪码调相技术的二进制化，进一步提高了系统的可靠性和即插即用性。提出了一种“主-从Rake”接收机，解决了信号的抗多径问题。所提出的导航信号和通信信号可以联合使用，也可以各自独立使用，具有良好的灵活性。此外，在卫星导航/通信一体化信号的研究基础上，项目组提出了多峰值类的伪码调相信号，进一步提高了传输速度，使该技术可以辐射到卫星应用外的其他应用领域。所提的信号体制对传统GNSS信号具有良好的向下兼容性，方便进行系统升级，且保持了传统接收机的定位能力，具有良好的可推广性。