Push the limit of WiFi based localization for smartphones
Push the limit of WiFi based localization for smartphones
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DOI：
10.1145/2348543.2348581
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发表时间：
2012-08
期刊：
影响因子：
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通讯作者：
Hongbo Liu;Yu Gan;J. Yang;Simon Sidhom;Yan Wang;Yingying Chen;Fan Ye
中科院分区：
文献类型：
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作者：
Hongbo Liu;Yu Gan;J. Yang;Simon Sidhom;Yan Wang;Yingying Chen;Fan Ye
智能手机的高度准确的室内定位对于为用户和企业实现新颖的基于位置的功能至关重要。在本文中，我们首先进行了实证调查的WiFi定位的适用性。我们发现，虽然可以实现合理的准确性，但显著的误差（例如，$6\sim8m$）始终存在。根本原因是存在具有相似签名的不同位置，这是纯WiFi方法的基本限制。受公共场所智能手机高密度的启发，我们提出了一种对等辅助定位方法来消除这种大的错误。它获得精确的声学测距估计之间的对等手机，然后映射他们的位置联合对WiFi签名地图受到测距约束。我们设计了多个电话之间的快速声学测距技术，并建立了一个原型。实验表明，它可以将最大和80%的错误减少到200万美元和100万美元，时间不超过原来的WiFi扫描，对电池寿命的影响可以忽略不计。
Highly accurate indoor localization of smartphones is critical to enable novel location based features for users and businesses. In this paper, we first conduct an empirical investigation of the suitability of WiFi localization for this purpose. We find that although reasonable accuracy can be achieved, significant errors (e.g., $6\sim8m$) always exist. The root cause is the existence of distinct locations with similar signatures, which is a fundamental limit of pure WiFi-based methods. Inspired by high densities of smartphones in public spaces, we propose a peer assisted localization approach to eliminate such large errors. It obtains accurate acoustic ranging estimates among peer phones, then maps their locations jointly against WiFi signature map subjecting to ranging constraints. We devise techniques for fast acoustic ranging among multiple phones and build a prototype. Experiments show that it can reduce the maximum and 80-percentile errors to as small as $2m$ and $1m$, in time no longer than the original WiFi scanning, with negligible impact on battery lifetime.