Android的相对定位，无线：到达时间 [英] Android relative positioning, Wifi:Time of Arrival

问题描述

SRC： http://www.cisco。 COM / EN / US /文档/解决方案/企业/移动/ wifich2.html

我一直在试图理解我怎么能确定彼此的2 Android设备的相对位置，0.3米精度范围内。

I have been trying to understand how I can determine the relative position of 2 android devices from each other, within 0.3m accuracy.

（注意：不是绝对位置，所以我能避免GPS干脆，我需要两个设备之间的频繁和快速更新）

(Note: not absolute position, so I can avoid GPS altogether, and I need frequent and fast updates between both devices.)

到目前为止，我已经确定算法，如到达时间算法将在无线网络中使用时的工作，如果发送的消息（从一个HW点）的准确时间是已知的。

So far I have determined that Algorithms such as "Time of Arrival" algorithms will work when used across WiFi, if the exact time a message is sent (from a HW point of view) is known.

这是我用尽脑力。任何人对我将如何实现这个任何想法？
或者有什么更实际的选择。

This is where I run out of brainpower. Anybody have any ideas on how I would implement this? Or any more practical alternatives.

先谢谢了。

推荐答案

无线电信号以光的速度是每纳秒约1英尺（0.983英尺/ NS是precise）行驶。因此，要获得0.3米精度（即约一英尺），你需要你的采样分辨率小于纳秒半 - 的东西，不能在操作系统级别，其中毫秒级的处理延迟出现完成

Radio signals travel at the speed of light which is about 1 foot per nanosecond (0.983 ft/ns to be precise). So to get 0.3 m accuracy (which is about a foot), you need your sampling resolution to be less than half a nanosecond -- something that cannot be done at the Operating System level, where millisecond-level processing delays occur.

不幸的是，做时间的到达对Wi-Fi或时间差的到达位置的处理，你需要一个专门的芯片组，提供了时间戳字段。我没有验证的信息，但看四向TOA和IEEE 802.11设备基于软件的三边的赫内斯和放大器; Willmann上citeseer - 表1包含芯片厂商实现TSF的列表。作者甚至提供 http://sourceforge.net/projects/goodtry/ 其code。

Unfortunately, to do Time-Of-Arrival or Time-Difference-Of-Arrival location processing on Wi-Fi, you need a specialized chipset that provides a Time-Stamp Field. I did not verify the info, but look at "Four-way TOA and Software-Based Trilateration of IEEE 802.11 Devices" by Hoene & Willmann on citeseer -- Table 1 contains a list of chip vendors that implement TSF. Authors even provide their code at http://sourceforge.net/projects/goodtry/.

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