面向下一代GNSS的多载波恒包络复合信号设计与接收技术研究

The conflict between limited spectrum resources, limited transmit power and growing positioning navigation and timing requirements has become the bottleneck for the next generation GNSS signal design. Multi-carrier constant envelope composite signal has the inherent characteristics of high spectrum utilization, high power efficiency and diversified receiving strategies, which is an effective way to solve the conflict between spectral efficiency and ranging accuracy, and between power efficiency and service diversity simultaneously. However, at present, there is still few studies on this new navigation signal structure. Both the methodology, implementation, and receiving methods of this signal are deficient, which lack of systemic research. In accordance with this situation, based on our previous substantial progress of constant envelope multiplexing design research, this project studies the general design methodology, high performance generating and receiving techniques of multi-carrier constant envelope composite signal, focused on the internal mechanism of multi-carrier constant envelope multiplexing design, composite signal generalized signature waveform optimization, multi-carrier constant envelope composite signal optimum implementation technology, and diversified multi-carrier receiving strategies, establishing and improving basic theories and methods of multi-carrier satellite navigation signal design, exploring the solutions to the optimal satellite navigation signal design under the bandwidth-power double limited condition, presenting the high performance multi-carrier constant envelope composite signal solutions, and providing theoretical and technical support for the next generation of global navigation satellite system signal design.

有限的频谱资源、受限的发射功率与不断增长的定位导航与授时需求之间的矛盾是制约下一代全球导航卫星系统信号体制设计的瓶颈问题。多载波恒包络复合信号具有高频谱利用率、高功率效率、多样化接收模式的特点，是同时解决频谱效率与测距精度，以及功率效率与服务多样性之间双重矛盾的有效途径。但目前这种新型导航信号体制的设计方法、实现技术、接收方法尚未得到系统性的研究。针对这一现状，本项目在近年来在恒包络复用设计研究取得的实质性进展基础上，对多载波恒包络复合信号的设计理论与发射接收方法进行研究，从多载波信号恒包络复用内在机理、复合信号广义特征波形优化设计、多载波复合信号最优生成与多样化接收等方面入手，建立和完善多载波卫星导航信号设计的基本理论和基本方法，探索带宽功率双重受限条件下的最优卫星导航信号设计的解决途径，提出高性能的多载波恒包络复合信号方案，为下一代全球导航卫星系统信号设计提供理论和技术支撑。

多载波恒包络复合信号具有高频谱利用率、高功率效率、多样化接收模式的特点，是同时解决无线电导航系统在频谱效率与测距精度之间，以及功率效率与服务多样性之间双重矛盾的有效手段。但这一信号体制的设计方法、实现技术、接收方法以及应用方式缺乏系统性的研究。为了能够将这一全新的解决思路落实为具体的技术方案，并在星基、空基、陆基无线电导航系统中充分发挥该信号的性能优势，本项目在完善多载波恒包络复用理论工具的基础上，重点从信号生成、信号接收、信号应用和信号性能评估这四个维度开展了研究工作。建立了多载波恒包络复用的统一数学框架，给出了多载波恒包络复用效率的可达性能界，完善了导航信号恒包络复用的理论基础。在此基础上，提出了多种可以抑制信号生成与传输过程中的交调分量与信道非理想性影响的多载波恒包络（或准恒包络）复合信号设计方法，及其高灵活性低复杂度的星上实现技术，并紧密结合多载波复合导航信号频谱稀疏的特征，提出了基于频谱感知的多载波导航信号处理方法、基于双环结构的多载波导航信号处理技术，此外还将多载波复合信号的应用范围从卫星导航系统扩展到一般的无线电导航系统，针对其特点提出了多种载波及副载波观测量的高精度提取与载波定位新方法新技术。本项目所提出的部分新技术已在新一代北斗卫星导航系统中得到了应用。项目研究成果不仅为下一代卫星导航系统信号设计、载荷实现、接收机开发提供了丰富有效的手段，而且对未来其他空基、陆基无线电定位系统的信号设计与接收处理也可以提供重要的参考。