泛在环境下的无线定位优化技术研究

发布时间：2018-03-08 11:38

本文选题：无线定位　切入点：时间同步　出处：《北京交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着物联网技术的发展和第五代移动通信系统的兴起,无线定位对于人们生活越来越重要。无论是室外的路线导航或是空间受限环境下的安全管理都离不开位置信息。但室外环境存在卫星信号不可得的情况,空间受限环境受到信号遮挡和多径的影响。不同的定位场景和系统存在其局限性与技术要点,同时考虑定位精度、设备成本和算法复杂度等因素,对于泛在环境下的无线定位技术优化研究是十分必要的。本文通过查阅文献并分析现有泛在环境下定位技术,分别对无线传感网同步与定位联合算法、低轨双星静止辐射源定位和移动辐射源跟踪技术以及非视距环境下定位三个方面进行了研究,主要的研究内容和创新点如下:(1)在对无线传感网定位的研究中,同步与定位是其研究的热点,本文考虑锚节点非同步的情况,提出对锚节点的时钟相偏、时钟频偏和源节点未知位置综合求解的算法。为了降低未知数个数,将所有锚节点进行分簇处理,簇内节点存在相同的时钟相偏和时钟频偏,使用到达时间差方法对方程变形,进而消除源节点导致的同步问题。由于泰勒级数算法的非收敛问题,引入正则化理论对其进行修正,最后使用改进的泰勒级数算法求解锚节点时间参数与源节点位置。(2)低轨道卫星存在轨道低、数量多和时延小等特点,本文采用低轨双星时差频差联合算法,考虑卫星星历、卫星时钟和测量等误差,对于静止辐射源,将其定位坐标与卫星系统时钟偏差和频率偏差使用迭代算法共同求解。对于移动辐射源,借鉴伪距差分算法实时地对测量值进行修正。首先利用已知位置参考站计算到达时间差和到达频率差的修正参数,然后利用修正参数修正移动辐射源测量的时间差和频率差,最后采用扩展卡尔曼滤波进行位置跟踪。仿真结果表明,联合参数算法和差分修正算法可以比未修正时取得更好的效果。(3)在存在参考节点不足和遮挡的情况下,本文分别引入了改进的到达角度定位方法和协作定位。协作定位中的移动终端不仅可以与参考节点通信还可以与移动节点通信来降低参考节点的布设成本,根据与待测节点是否存在视距路径来选取协作节点,而改进的到达角度定位算法在于利用参考节点和移动终端的接收角度协作关系,从而获得一个移动终端可能存在的区域,最后利用最小二乘求解。仿真表明改进的到达角度定位方法可以取得更好的结果。
[Abstract]:With the rise of the development of Internet technology and the fifth generation mobile communication system, wireless location is important for people living. Whether outdoor or route navigation safety management limited space environment all cannot do without the location information. But the existing outdoor environment satellite signal is available, the limited space environment affected by the signal occlusion and multipath. Some limitations and technical points of different scenarios and positioning system, the positioning accuracy, the equipment cost and the complexity of the algorithm and other factors, the ubiquitous environment of wireless positioning technology optimization research is very necessary. In this paper, through literature review and analysis of existing positioning in the environment of technology, respectively. The wireless sensor network synchronization and location combined algorithm, low orbit binary static emitter location and tracking technology and mobile radiation source under the NLOS environment positioning three aspects For the study, the main research content and innovation points are as follows: (1) in the study of localization in wireless sensor networks, synchronization and localization is the research hotspot, synchronization of non anchor nodes is considered in this paper, the anchor node Shi Zhongxiang offset, frequency offset and clock algorithm for unknown source node position synthesis in order to reduce the number of unknowns, all anchor nodes are grouped into clusters and cluster nodes have the same clock phase offset and clock frequency offset, using time difference method of equations of deformation reach, and eliminate the synchronization problem caused by the source node. Due to the non convergence of Taylor series algorithm, introduce the regularization theory of its finally, using the Taylor series correction algorithm for the anchor node time parameters of the source node and the improvement of the position. (2) low orbit satellite orbit is low, and the number of small delay characteristics, this paper uses low orbit dual star TDOA-FDOA joint count By considering the satellite ephemeris, satellite clock and measurement error for stationary radiation source, the location coordinates and satellite clock offset and frequency offset using the iterative algorithm to solve. For mobile radiation source, from the pseudo range are carried out on the measurement value of real-time algorithm. First use of known position calculating the time difference of arrival and reach the correction parameters of the frequency difference of reference station, and then use the correction parameter correction moving radiation source measuring time difference and the frequency difference, finally using the extended Calman filter for position tracking. The simulation results show that the combined parameter algorithm and differential correction algorithm can obtain better effect than unmodified. (3) in the presence of reference node deficiency and occlusion, this paper introduces the improvement of the angle of arrival positioning method and cooperative localization. Cooperative localization in mobile terminal can not only with the reference node communication We can also reduce the cost of the layout of the reference node and the mobile node communication, to select cooperative nodes in accordance with the unknown node exists beyond the path, and improve the angle of arrival positioning algorithm is to use the reference node and the mobile terminal of the receiving angle of cooperation, so as to obtain a mobile terminal may exist in the region, finally using the least squares method. Simulation results show that the improved method can reach the positioning angle to achieve better results.

【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5;TP212.9

【参考文献】