【作者】 王旭；

【导师】 何子述；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2011， 博士

【摘要】 时分多址(TDMA)系统以其组网灵活、支持多业务等特点,在无线通信中占有重要位置。无源定位技术以其隐蔽能力强、作用距离远等特点在现代信息化战争中获得广泛应用。针对单站TOA(到达时间)系统、单站TOA和DOA(到达方向)系统、双站TOA系统以及三站TOA系统,利用TDMA系统特征,本文研究获取TDMA目标位置参数的算法以及提高参数估计精度的途径。本论文以TDMA系统的运动目标(终端)无源态势信息获取算法为主,在多站无源定位中兼顾TDMA固定目标定位,主要的创新之处如下:1.实现了TDMA系统特征和目标位置参数估计算法的有机统一。首先,TDMA系统是一个同步系统,任意两个时隙信号的发射时间间隔为时隙持续时间的整数倍,可以认为TDMA时隙信号是准周期信号。TDMA的同步特性是进行单站和多站纯TOA目标运动分析的基础。其次,TDMA系统是一个多目标系统,多目标之间是同步的,运用于多目标同步特性能够提高多目标的定位精度。2.在单站纯TOA目标运动分析中,提出了适合任何快拍数的以距离和速度为变量的封闭形式距离和速度估计算法,分析了目标相向运动和相背运动对距离和速度估计精度的影响,提出了前向和后向估计算法。为充分利用整个快拍数据的信息,给出了全局最小二乘测距测速算法,做到了距离和速度总体最优估计。3.在单站TOA和DOA目标运动分析中,运用参数化目标运动分析的方法分析目标位置的可观测性条件,并推导了定位精度的理论算法。该定位算法不需要对非线性观测方程进行任何线性化处理,用三个以上目标位置的测量值实现对TDMA目标的单站定位。4.在双站纯TOA目标运动分析中,对目标各种位置参数的可观测性进行了分析,给出了三维目标各种距离和速度的估计算法,对估计精度进行了仿真对比分析;提出了二维目标的位置坐标和速度分量的估计算法,在一般意义下能够得到目标位置坐标和速度分量的二值估计,给出以两个接收站的轴线为对称的上下两条目标运动航迹,借助目标活动的区域或方向测量值可以去掉目标的虚假航迹,实现二维目标的定位。5.在三站纯TOA目标运动分析中,分析了三维目标各种距离和速度的估计算法;提出了二维目标的位置坐标和速度分量的估计算法,只要三个接收站不在一条直线上,能够实现二维目标的位置坐标和速度分量的唯一估计;同时给出了三维目标的位置坐标和速度分量的估计算法,在一般意义下能够得到目标位置坐标和速度分量的二值估计,由于空中飞行目标的高度不可能为负值,去掉目标的虚假位置,可以实现三维目标的定位。6.对于传统的三站时差定位系统,根据TDMA系统的基站位置坐标已知的情况,由时隙信号的TOA可以推算出目标的距离,提出了两种TDOA和TOA联合定位的算法,可以提高时差定位算法的精度。在TDMA系统多目标情况下,即使不知道基站位置坐标,给出了两种多目标联合时差定位算法,避免了传统时差定位算法中的模糊和无解情况,由于利用所有目标的时差信息对目标进行定位,在多目标情况下提高了目标定位的精度。对于运动TDMA目标,提出了三种在三站时差定位系统中实现目标定位的算法。采用目标运动分析的方法,对TDMA目标位置的可观测性进行分析,实现了目标运动分析时差定位算法。运用目标运动分析测距算法,提出了测距与传统时差定位和目标运动分析时差定位相结合的两种定位算法,充分利用了目标的运动特性,提高了TDMA目标的定位精度。与现有的纯方位目标运动分析和多站时差定位相比,本文深入研究了单站、双站和三站的纯TOA目标运动分析,提出了距离速度估计闭式解及其性能改进算法;利用TDMA系统的时间同步特征,实现了多种TDMA系统单目标和多目标的时差定位算法,不仅提高了定位精度,还避免了模糊与无解现象。该研究成果对实际TDMA系统目标无源定位具有指导意义,部分算法已在实际的单站和多站定位系统中得到应用。更多还原

【Abstract】 Time division multiple access (TDMA) system plays an important role in wireless communication which has the advantages of flexible of networking architecture and multi-service support.Passive location technology is widely used in modern information warfare because of its strong hidden ability and long operation distance.Based on the study of the features of the TDMA system, this dissertation investigates target location estimation algorithms and provides methods for improving the estimation accuracy. Location systems with single-sensor time of arrival (TOA), single-sensor TOA and direction of arrival (DOA), bi-sensor TOA and tri-sensor TOA are considered.This dissertation focuses on localization algorithms for moving TDMA targets, and for fixed TDMA targets in multi-sensor localization systems.The contributions of this dissertation are as follows:1. The features of the TDMA system are employed in the target location algorithms. Firstly, the TDMA system is time synchronized. The time difference between the transmission of signals at different slots is an integer multiple of the slot signal cycle. Hence, the slot signal can be considered as quasi-periodic. The synchronization of the TDMA system makes it possible for single and multiple station TOA-only target motion analysis. Secondly, the TDMA system has multiple targets which are synchronous in time. The target location accuracy can be improved by the use of multi-target synchronization.2. For the TOA-only target motion analysis (TMA) in a single-sensor system, the closed-form algorithm of range-velocity estimation is proposed which is suitable for any number of snapshots of TOAs. The estimation accuracies are analyzed for targets that move towards or away from the localization system. The forward and the backward estimation algorithms for range-velocity estimation are presented. In order to fully utilize the data information of the entire snapshot, the globally-weighted least-square range estimation algorithm is proposed which leads to an overall optimal range estimation.3. In the single-sensor TOA and DOA target motion analysis, the parametric TMA method is used in analyzing the observability condition of the target position, which deduces the theoretic analysis algorithm of location accuracy. The single-sensor location of the TDMA target can be realized using measurements of more than two target positions without the linearization of nonlinear observation equation.4. For the dual-sensor system, algorithms for the estimation of range, velocity, velocity components and position coordinates are proposed, and respective observabilities for the above target motion parameters are analyzed. In addition to the situation of target motion on the sensor axis, these algorithms can estimate the range and velocity of moving target in three-dimensional space, and make two-valued estimations of velocity components and position coordinates for two-dimensional target and then obtain two upper and lower trajectories symmetrical to the connecting line of the two sensors. The false trajectory can be excluded by the information of the region or bearing of moving target and then the target can be located.5. In the three-sensor time different of arrival (TDOA) location system, the algorithms to estimate its range, velocity, velocity components and position coordinates are presented. Unique solutions of velocity components and position coordinates of two-dimensional target can be obtained by using the TMA method. For the target moving with a constant speed in a three-dimensional space, the two-valued estimations of its velocity components and position coordinates can be obtained. Since the height of a flying target cannot be negative, the false position can be excluded.6. In the traditional TDOA localization system, if the base station position of the TDMA system is known, the target range will be calculated according to the TOA of a slot. Two kinds of joint localization algorithms of TDOA and TOA for TDMA target are proposed. Two weighed least square algorithms for multi-target ranging and locating are presented in order to improve the localization precision. For TDMA moving target, three location algorithms are proposed based on the measurements of TOA. The TMA method is used to analyze the observability condition of target position, and realize the TMA TDOA localization of moving target (TDOA-M). Two joint algorithms of conventional TDOA location (TDOA-C) and TDOA-M with TMA ranging algorithm are proposed to improve the localization precision by making full use of the target motion property. The ambiguity and non-solution problems in the traditional TDOA location algorithm are avoided in these algorithms. In contrast with the existing bearing-only TMA and multi-station TDOA localization approaches, the TOA-only TMAs of single, bi- and tri-station are lucubrated. The closed-form algorithm of range-velocity estimation and its improved algorithms are proposed. Several TDOA location algorithms of single and multi-target are realized by the use of the synchronization characteristic of the TDMA system. The results of this work are instructional for the actual passive location of the TDMA targets. Some parts of these algorithms have been applied to the actual single and multi-station location systems.更多还原