近年来定位和同步的应用在人们的日常生活和工作中变得越来越重要，比如监测、灾难救援、自动驾驶以及物联网等。在网联车、无人机编队、区域监测等多节点网络的应用中，每个节点对协作信息需求不断增加，同时对快速定位与同步的要求也越发迫切，然而已有的卫星导航系统在卫星信号拒止场景下难以满足上述需求。随着新一代通信的发展，涌现出了全双工（Full Duplex）、大规模天线阵列等新的技术。全双工技术的应用使无线网络中节点能够同时同频地实现信号的接收和发送。天线阵列可以为网络定位的应用引入角度的测量。这些新技术可以大幅提升网络定位的性能，进而提升网络效率。因此，本文利用新的通信技术，研究基于协作框架的网络定位和同步的理论和算法，取得了以下创新性的成果。首先，提出一种基于全双工的通过两帧通信实现网络协作定位和同步的方案，并推导了节点定位和同步精度的理论极限。与基于传统通信技术的定位方案进行了对比，证明了基于全双工技术的方案性能优于基于频分双工的方案性能。数值结果验证了所提方案在不同参数设置下的优良特性。其次，提出了一种并行的互干扰消除的方法，进而设计了在全双工模式下到达时间等参数的估计算法。在信噪比估计的基础上，设计了先解算同步和距离参数，再进行解算节点位置的流程框架算法。仿真结果验证了所提算法的有效性，算法实现的精度在高信噪比下接近理论界。再次，提出了一种基于单基站的全双工节点定位和同步的方案，并推导了待估计参数性能的闭式表达式等。将相关函数由时域转换到频域，进而设计了一种到达角度和到达时间等参数的联合估计算法。在理论界估计的基础上，设计了高精度的定位和同步的求解算法框架。最后，在动态场景中分析了状态演进和观测更新的基于全双工技术的网络协作定位和同步的时空协作机理。提出了在单历元下先定位再定速，之后进行联合优化的求解算法，进一步设计了多历元下的位置等参数的求解算法框架。仿真结果验证了时空协作的优势，表明了算法实现的有效性。综上所述，本文面向卫星信号拒止场景下的重大需求，提出了系统性、有效、可行的协作定位和同步的方案，有利于我国综合定位导航授时体系的建设和完善，具有较大的理论和应用价值。
The application of position and time has become increasingly important in people’s daily lives and work, such as monitoring, disaster relief, autonomous driving and the Internet of Things. In the application of multi-node networks such as networked vehicles, drone formations, and regional monitoring, the demand for collaborative information is increasing for each node, and the requirements for rapid localization and synchronization are becoming more urgent. However, the Global Navigation Satellite Systems (GNSS) are difficult to meet the above requirements in the GNSS-denied environments. With the development of new generation communication, new communication technologies such as simultaneous full duplex, large-scale antenna arrays have emerged. The application of the full duplex technology enables nodes in a wireless network to simultaneously receive and transmit signals at the same frequency band. Antenna arrays can introduce angle measurements for network localization applications. These new technologies can greatly improve the performance of network localization, thereby improving network efficiency. Therefore, this paper uses the new communication technologies to study the theory and algorithm of network localization and synchronization based on the collaborative framework, and has achieved the following innovative results.Firstly, we propose a scheme based on the full duplex for network cooperative localization and synchronization through two-frame communication, and derive the theoretical limit of node localization and synchronization. Compared with the localization schemes based on traditional communication technologies, it is proved that the performance of the scheme based on the full duplex technology is better than that of the scheme based on the frequency division duplex. The numerical results verify the excellent characteristics of the proposed scheme under different parameter settings.Secondly, we propose a parallel method of mutual interference cancellation, and then design an estimation algorithm for parameters such as arrival time in the full duplex mode. Based on the signal-noise-ratio (SNR) estimation, a process framework algorithm for solving the synchronization and distance parameters and then solving the node position is designed. The simulation results verify the effect of the proposed algorithm. The accuracy of the algorithm is close to the theoretical limits under high SNR.Thirdly, we propose a scheme for the full duplex node localization and synchronization based on a single base station, and derive the closed-form expression of the parameters’ performance. The correlation function is transformed from the time domain to the frequency domain, and a joint estimation algorithm for parameters such as arrival angle and arrival time is designed. Based on the theoretical estimation, a high-precision algorithm for localization and synchronization is designed.Finally, we analyze the spatial-temporal cooperation mechanism of network cooperative localization and synchronization based on the full duplex technology in the dynamic scenario. Under a single epoch, we propose an algorithm for localization first, then determining velocity, and at last joint optimization. The algorithm framework for solving parameters such as position under multi-epoch is further designed. The simulation results verify the advantages of spatial-temporal cooperation and demonstrate the effectiveness of the algorithm implementation.In conclusion, this thesis develops the systematic, effective and feasible methods of the cooperative localization and synchronization for the major demand in the GNSS-denied environments, which is conducive to the construction and development of China’s integrated Positioning, Navigation and Timing system (PNT), and it has great theoretical and application value.
