SBIR Phase I: High Resolution Channel Sounding for Indoor TDOA Positioning Using Narrowband RF Transceiver

该小型企业创新研究第一阶段项目专注于针对室内或杂乱室外环境的无线到达时间差(TDOA)定位技术。到目前为止，室内TDOA技术几乎没有商业成功，主要是因为表面的多径信号反射模糊了空中信号的到达时间，使得从视线或最短距离路径确定位置信标的到达时间变得困难。对抗多径的最好方法是使用非常宽带的信标信号。宽的信号带宽提高了时域的分辨率，允许接收器区分不同的路径。使用如此宽的信号带宽的一个关键挑战是，它不能用商业上可获得的高度集成的低成本组件来完成。另一个制约因素是限制此类信号发射功率的监管限制。这项研究的重点是开发一种克服这些实际限制的方法，方法是定义一种特殊类型的窄带定位信标，该信标提供与超宽带信号相同的性能，但可以使用负担得起的现成无线电组件来实现。大量应用可以受益于高分辨率室内定位技术，包括：智能手机的室内楼层地图定位和路线指南、基于室内位置的广告、室内E911、基于位置的安全、医务人员和资产监控以及搜索和救援。然而，现有的解决方案，如最近接入点或接收信号强度三角测量，由于实现这种精度所需的高密度，既不够准确，也不具成本效益。有一些基于超宽带的TDOA解决方案具有更好的准确性，但由于FCC功率限制和迄今有限的市场成功，这些网络的覆盖范围有限。WiFi已经给无线移动性带来了革命性的变化，这里介绍的解决方案将利用WiFi作为一种上市战略。如果成功，该解决方案将不受监管权力限制，而且将是负担得起的，因为它是基于WiFi的。

This Small Business Innovation Research Phase I project is focused on wireless Time Difference Of Arrival (TDOA) positioning technology for indoor or cluttered outdoor environments. Indoor TDOA technologies have had little commercial success to date primarily because of multipath - signal reflections off of surfaces that smear the arrival time of the over-the-air signals, making it difficult to determine the arrival time of the location beacon from the Line-Of-Sight or shortest distance path. The best way to combat multipath is to use very wideband beacon signals. The wide signal bandwidth increases the resolution in the time-domain, allowing the receiver to distinguish between paths. A key challenge with using such wide signal bandwidths is that it can?t be done with commercially-available highly-integrated low-cost components. Another constraint is regulatory restrictions that limit the transmit power of such signals. The focus of this research is to develop a way to overcome these practical limitations by defining a special type of narrowband location beacon that gives the same performance as very wideband signals but that can be implemented using affordable, off-the-shelf radio components. A great number of applications could benefit from high-resolution indoor location technology, including: Indoor floor map positioning and route guidance for smartphones, indoor location-based advertising, indoor E911, location-based security, medical staff and asset monitoring and Search and rescue. However, existing solutions such as nearest Access Point or Received Signal Strength triangulation are neither accurate enough nor cost-effective due to the high density required to achieve this accuracy. There are TDOA solutions based on Ultra WideBand that have better accuracy but these networks have limited range due to FCC power limitations and limited market success to date. WiFi has already revolutionized wireless mobility and the solution presented here will leverage WiFi as a go-to-market strategy. If successful, the solution will not be limited by regulatory power restrictions and will, because it is based on WiFi, be affordable.