Key Technologies of Large-Scale Indoor Ultra- Wideband Iocalization Network

Ultra Wide Band (UWB) technology interests many scholars in the world, because it is a totally new communication technology which is different with the traditional ones.There is great value of UWB technology in communication, radar and locating domain.Comparing with traditional wireless communication technology such as Bluetooth,IEEE802.11, UWB is preferred in indoor locating because of its high transmission rate,high system capacity, low power consumption, good anti-multipath performance, goodpenetrability and high locating accuracy. The locating for moving objects based on UWB and wireless sensor network is a popular research topic recently. Currently, manycountries are focusing on the research and development of UWB locating technology and the relative products to monopoly the UWB market. Lots of famous universities andlaboratories are doing the research about the UWB technology, and many UWB locating systems are designed suecessfully.

As the new generation information technology and manufacturing industry get integtated, location based service (LBS) is of significant importance to solve the problems incurred by the digitalization and networking in the production process. Being the fundamental technology of LBS, indoor localization plays an indispensable role in realizing intelligent manufacture. However, when conventional indoor localization system is applied in complex, dynamic and unstructured industry environments, its performance is seriously degraded. There are still many challenges in framework design,location estimation, data transmission and information processing. Thus, it is urgent to carry out the in-depth study of a complete technical system, which is an important direction for complex industrial environment. To meet the demands of industrial scenarios, some key problems such as system framework, localization model, network,data processing are studied. An indoor localization system for complex industrial environments is proposed in this dissertation.

Research on TDOA Location Algorithm for Ultra-wideband Precision Real-Time Iocation System

本文选用超宽带(uwB)技术作为基础，以实现高精度室内人员定位的要求。文中选用IEEE802．15．4a模型作为uwB的信道模型，利用Matlab软件仿真uwB发射及接收信号，通过wylie算法鉴别目标节点与参考节点间的Los和NLos传播，筛选出性能更优的参考节点，更新到达时间差，得到较为准确的初值估计，保证之后的算法收敛。同时推算出可靠度最高的参考节点与目标节点的方位角、俯仰角信息，将其代入基于泰勒级数的TDoA／AoA混合算法后，进行三维定位，最后利用Maclab模拟及分析不同算法三维定位情况。与其他算法相比，优化后的混合算法在各种情况下均表现出了更为良好的定位精度，显示了其应用于室内定位的优势。

With the presentation of ″Internet+″ and continuous development of Internet of Things technology，the scenes to locate the staff and goods are increasing. At the same time，the demands of emerging fields（such as security monitoring，aero⁃space，unmanned industrialization operation，seas exploration，digital tourism）for indoor positioning are growing. To satisfy dif⁃ferent requirements，various positioning technologies were developed by the academia and industry，but they have great dif⁃ferences in the aspects of positioning applicability，positioning accuracy，etc. In comparison with other positioning methods，the UWB（ultra wideband）positioning technology has the unique advantages in positioning accuracy，real⁃time performance and data scalability. In this paper，the algorithm based on TDOA（time difference of arrival） was improved to reduce the difficulty of clock synchronization，and in combination with Kalman filtering，the error interference in transmission process was eliminated.The method can make the indoor positioning more accurately.

Along with the rapid development of urbanization in China, there is a contradiction between the popularization of automobiles and the slow growth of road mileage. The "Skyrail" of green new energy train is one of the means to solve the current contradiction. The driverless system used in the "Skyrail" is the highest level of full-automatic driverless system. In addition, the high requirements of rail transit for safety mean that the "Skyrail" positioning is an essential link. The most important problem in the "Skyrail" positioning is the positioning accuracy. In order to meet the high-precision requirements in the "Skyrail" positioning, according to the existing train positioning technology, we propose the "Skyrail" parking section positioning scheme and the driving tracking positioning scheme based on UWB technology.

In wireless positioning environment based on Ultra Wideband Radio (UWB), as a result of the integrated influence of several disadvantages including multipath、non-line-of-sight (NLOS) propagation 、interference and channel frequency characteristics, the measurements of the features in TDOA, TOA, AOA inevitably get some errors, leading to the performance of all sorts of positioning algorithm dropping significantly. What’s worse, greater deviation of positioning estimation emerges.Centered on the core issue –improving the positioning accuracy, on the basis of multi-base station positioning algorithm as well as the advanced single base positioning algorithm, this paper conduct a deep research of UWB wireless positioning technology from four main aspects: analysis of the multi-base station TDOA positioning algorithm, anti-NLOS high-accuracy positioning technology,hybrid positioning algorithm, single base station positioning algorithm based on antenna array.

本文首先对UWB无线通信技术和基于接收信号的到达时间差(Time Difference of Arrival, TDOA) 算法的国内外发展现状做了简单说明介绍。之后对UWB室内定位系统的应用进行了详细的说明，并对几种定位算法的实现进行了理论分析和推导。在此基础之上，通过对UWB室内定位系统的硬件模块介绍，提出了TDOA算法在嵌入式室内定位系统中的实现。最后,通过在HainanEVK实验平台进行室内定位测试，对定位结果进行误差分析并测量系统功耗。大量的实验分析和性能比较表明基于TDOA算法的UWB室内定位系统在精确定位的同时,能减少基站与终端的相互通信，从而降低系统的功耗，在-定程度上更适合于多标签大规模的室内精准定位。

本论文就如何利用阵列天线的信号到达角度（DOA）和超宽带信号的到达时间差（TDOA）来提高室内定位精度的问题进行研究。