基于波形边缘检测的Wi-Fi室内定位信号TOA估计-《郑州大学学报(工学版)》

文章信息/Info

Title:: TOA Estimation of Indoor Localization by Wi-Fi Signal Based on Waveform Edge Detection

Author(s):: Ma Dongyu; Li Min; Zhang Duanjin;; School of Information Engineering, Zhengzhou University; Institute of China Electronic Equipment System Engineering Company;

Keywords:: Signal reaching time; indoor positioning; waveform edge detection; wi-fi; channel status information; phase information

摘要:: 摘要: 为了实现室内目标的精准定位,研究基于 Wi-Fi 设备的信号到达时间( TOA) 参数具有重要意义。常用 TOA 估计方法主要存在估计偏差、算法复杂以及不具有普适性等问题。针对现有方法的缺陷,提出了一种新的 TOA 估计方法。该方法对 Wi-Fi 信号波形进行采样,采用空-频-时三维搜索算法,计算某一子载波间隔一个采样周期的相邻区间分别对应的信道状态信息的相位差,通过相位差判断计算信道状态信息值的信号处理区间是否进入波形边缘,得到 TOA 的估计值。数值仿真结果表明:在信噪比 SNR 超过 25 dB 时,本文方法获得亚米级精度的概率超过 58%随着 Wi-Fi 信号带宽的扩展,本文方法能够显著提升室内定位性能。本文方法克服了传统方法的缺陷,为信号到达时间估计提供了一条新的思路。

Abstract:: Abstract : To locate the target indo or precise ly, it wa s im portan t to invest iga te on th e Wi- Fi based i ndoor lo-caliz ation param eter, namely, time of arr ival ( TO A) . The main weak ness of prim ary T O A esti mation m ethods were esti mation bias , comp lex a lgo rith m, an d lack of un iversality. T he new method h ad a cle ar physical mean-ing, a nd c ould p ave a new way for th e T OA estima tio n. A ccordin g to th e w eakness of these traditi ona l meth-ods, a new TO A estimati on algorith m w as propose d in this p aper . Base d on samp ling of w aveform, the space-frequ ency- time se arch ing algo rithm, t his a lgori thm calcula ted t he ph ase dif ference bet ween ad jacent CSI cal cu-lati on t ime sp an , and judged wh ether the C SI calc ulation t ime spa n cou ld reac h the edge of wavef orm, as to get the result of TOA es timati on. Numerical resul ts sho wed that th e n ew m ethod could ach ieve more tha n 5 8%submet er-level pr eci sion when the sig nal- to-nois e ratio was above 25 dB. Moreov er, th e performa nce of the meth od upgraded as the ba ndwi dth o f t he W i-Fi sig nal expan ded. The new method could overcome the weak-ness of trad itional method , and pave a new way for th e TOA esti mation.