无线定位中TOA估计算法的研究

发布时间：2018-04-04 22:10

本文选题：无线定位　切入点：多径信道　出处：《天津大学》2014年硕士论文

【摘要】：到达时间(Time of Arrival,TOA)估计方法是一种非常适合于室内复杂多径传播环境中应用的定位方法。噪声、多径干扰、收发系统间的不同步及非视距传播等是影响TOA估计精度的主要因素,目前亟待解决的一个基本问题就是如何精确地估计无线信号直达径的到达时间延迟。本论文主要针对无线定位中的到达时间TOA估计算法开展了深入地研究。首先,通过建立恰当的多径信道模型,对常用的TOA估计算法进行了研究。然后,在现有的TOA估计算法的分析研究基础上,提出了几种应用于无线定位中TOA估计的新的改进算法,分别为改进Teager-Kaiser算子的TOA估计算法、最大搜索斜率(Max Search Slope,MSS)算法和基于互相关的混合TOA估计算法。改进Teager-Kaiser算子算法中提出先对相关曲线作高次方运算来降低噪声的影响作用,再结合Teager-Kaiser算子进行TOA估计,并提出通过限定处理数据范围来降低计算复杂度的相应方案;MSS算法实现TOA的延迟估计的原理是相关曲线的变化率对应于TOA位置的值最大,通过在TOA值对应相关曲线的位置区间搜索变化率的“突变”位置进行TOA估计;考虑到噪声对TOA估计精度的影响,随后提出在相关函数的基础上结合小波去噪的方法来实现TOA估计的混合算法,先通过相关曲线得到多条差分曲线,并分别进行小波分解,提取对应于TOA值的小波系数,同时对其他系数做置零处理,再进行重构,将重构曲线作叠加平均处理得到对应的TOA估计值。对各种改进算法的仿真结果表明,所提出的改进算法对TOA估计的精度都有明显提高,性能优于传统的估计算法,特别是在噪声比较严重的情况下,TOA的估计精度得到很大的提高。
[Abstract]:Time of arrival (TO) estimation is a very suitable localization method for indoor complex multipath propagation environment.Noise, multipath interference, asynchronous and non-line-of-sight propagation between transceiver and transceiver systems are the main factors affecting the accuracy of TOA estimation. One of the basic problems to be solved is how to accurately estimate the arrival time delay of the direct path of wireless signal.In this paper, the time of arrival (TOA) estimation algorithm in wireless location is studied.Firstly, the common TOA estimation algorithms are studied by establishing an appropriate multipath channel model.Then, based on the analysis and research of the existing TOA estimation algorithms, several new improved algorithms for TOA estimation in wireless location are proposed, respectively, which are the TOA estimation algorithms for the improved Teager-Kaiser operator.Max Search Slope Search algorithm and hybrid TOA estimation algorithm based on cross-correlation.In the improved Teager-Kaiser operator algorithm, the high power operation of the correlation curve is proposed first to reduce the effect of noise, and then the TOA estimation is carried out by using the Teager-Kaiser operator.A scheme to reduce the computational complexity by limiting the range of data processing is proposed. The principle of TOA delay estimation based on MSS algorithm is that the change rate of the correlation curve corresponds to the maximum value of the TOA position.The TOA estimation is carried out by searching the "mutation" position of the rate of change in the position interval of the correlation curve corresponding to the TOA value, and considering the effect of noise on the accuracy of TOA estimation,Then a hybrid algorithm based on correlation function and wavelet denoising is proposed to realize TOA estimation. Firstly, several difference curves are obtained by correlation curves, and wavelet coefficients corresponding to TOA value are extracted by wavelet decomposition.At the same time, the other coefficients are set zero, then reconstructed, then the reconstruction curve is processed by superposition average to get the corresponding TOA estimate.The simulation results of various improved algorithms show that the proposed improved algorithm can improve the accuracy of TOA estimation obviously, and its performance is better than that of the traditional estimation algorithm, especially in the case of serious noise.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN92

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