位置，位置，位置：超宽带之路

尽管超宽带（UWB）已经存在了一段时间，但它被认为是最新的“定位技术”，并且正在以健康的速度发展。它的精确功能是它区别于其他定位解决方案的关键所在，它是令人兴奋且至关重要的新用例的关键推动者。

Location technology has traveled a long road to get to where we are with UWB, but howdidwe get here? To fully understand, it’s helpful to look at how it originated, the role it plays, how it works, and the use cases it powers. In this post, we look at the history of location technology and explore the solutions that led to the pin-point, real-time accuracy of UWB.

A Look Back at Location Technology

Stars, Maps and Compasses

Location technology stems back to the beginning of time. Celestial navigation has long been used for direction-finding, wayfinding, steering and piloting through position fixing. Then came the magnetic compass in the early 11th century. And, of course, paper maps, asking for directions, and trial and error helped people to find their way around the world.

Satellites Lead the Way

跃进到20世纪90年代末和2000年初，全球定位系统（GPS）逐渐成为主流。全球定位系统是定位技术的一个巨大进步，它让位于一个新的便利水平，在许多方面改变了我们的生活。它允许用户以电子方式定位最近的加油站，追踪健身情况，制定出行计划，并找到回家的路。对企业来说，好处远远不止是方便，而是效率的问题，甚至是建立可持续的商业模式的问题。如果没有GPS，公司会怎么想亚马逊,FedExandUPSefficiently navigate deliveries to your doorstep?

当大多数人想到定位技术时，他们想到的是全球定位系统（GPS），这是户外导航的首要技术。GPS的工作原理是利用卫星将独特的信号和轨道参数传输到地面站和接收器，比如移动电话。接收器使用来自4颗或更多卫星的信号进行解码，然后计算距离以找到其确切位置。

导航进来

十年后,我们看到另一个突破brought navigation inside, aptly called indoor navigation or positioning – think Google Maps for malls, airports, and other large buildings. Indoor positioning is, in many ways, an inside version of the satellite-navigation apps we rely on for outdoor navigation, but with an added twist – it can also be used to help locate people and things. Much like GPS, indoor navigation uses positioning systems made up of sensors and communication technologies – Wi-Fi, Bluetooth^®Low Energy (LE), Zigbee and Thread enabled devices – to locate objects in indoor environments.

无线室内建筑，每个房间都有一个吊舱，使用Wi-Fi、蓝牙等通信技术^®Low Energy (LE), Zigbee and Thread.

The Path to Small

Fast forward to today and we’re now seeing the rise of micro location-based systems. People and businesses want to be able to locate and find pretty much anything in real time, whatever its size. Let’s say you’re at home and misplaced your car keys, or you’re in a grocery store and can’t find your favorite brand of coffee. Or maybe you’re working in a factory and need a particular tool from a storage bin, or you’re a site manager dealing with an emergency and need to make sure everyone’s exited the building. Indoor positioning at the micro level helps in all these situations because it can locate items and guide you to where they are.

To offer enough accuracy, reliability and real-time capability, the underlying technology needs to be designed for precise location. This is where UWB technology is changing the game by delivering highly valuable location information across many different applications.

The adoption of Ultra-wideband (UWB) in flagship smartphones opens up the possibilities for much more precise, reliable indoor positioning and navigation than would be possible with BLE alone. Its extremely precise locating abilities can locate products and people within one centimeter.

Plotting the Micro-level Requirements

在微观层面上开发一种有效的室内定位技术需要做几件事。首先，位置读数需要非常精确，精确到尽可能小的区域。这项技术必须是安全的，因为地点往往需要保密。它还需要可靠，即使在恶劣的环境中，并且易于扩展，因此它可以处理大型场馆中成千上万的人员和资产。其他要求包括低功耗和经济性，因此它可以嵌入到从高端复杂设备（如智能手机）到低端简单设备（如资产标签）的所有产品中。当然，这项技术的延迟必须足够低，以便能够实时跟踪运动。

Requirements for Micro-based Indoor Positioning

When designing the first indoor location systems, engineers used the technologies that were available to them – usually Wi-Fi and Bluetooth Low Energy (BLE). While those technologies are great for data communication – what they were invented for – none of them were designed for real-time location services (RTLS), and therefore, don’t meet all micro-based indoor positioning requirements.

Wi-Fi、蓝牙和其他窄带无线电系统的精确度只能达到几米。他们的可靠性没有达到99.9%的要求，以建立安全和可信的系统。由于碰撞和干扰，成千上万的设备无法同时报告它们的位置，而且在实时位置服务环境中使用时，它们会遇到困难。以BLE为例，虽然它是低功耗数据通信领域的佼佼者，但获得一个“正常”位置点所需的措施和后处理数量会导致功耗和延迟高达数秒。

This is why back in the mid-2000s engineers from theIEEEstarted to specify a different kind of wireless technology specifically designed for accurate location that would check all the boxes. This technology was named Ultra-wideband (UWB) and has the potential to change the way we do all kinds of everyday tasks.

The use of UWB-enabled sensors, tags and smart devices that identify and locate people and things, combined with other hardware and software platforms, allow companies and organizations to conduct a multitude of real-time location services. These include applications from monitoring employee safety to asset location and process/flow optimization, which result in improved efficiencies, better compliance, and cost savings.

UWB：我们今天在哪里

UWB is based on theIEEE standard 802.15.4a/z, which has been optimized for micro-location and secure communication. UWB can pinpoint people and things to within just a few centimeters, making it 100 times more accurate than the current implementations of Bluetooth Low Energy (BLE) and Wi-Fi.

How is all this possible? Simply put: physics. UWB is more conducive for micro-location applications because it transmits wideband signals (500 MHz) and uses Time-of-Flight to determine location.

Why UWB is Best When Precise Location Matters Most

Figure 1 below compares narrowband and Ultra-wideband. The UWB pulse (center & right image) is only 2 nano seconds (ns) wide. This makes it immune to reflected signal (multipath) interference. As shown in the center and right images, the reflected signal (red) does not affect the direct signal (blue). These UWB signals also have much faster rise and fall edges than the narrowband signals (left). UWB signals maintain their integrity and structure even in the presence of noise and multi-path effects. Moreover, the UWB clean signal edges, allow precise determination of arrival time and distance.

图1：比较窄带信号​​，带有直接（蓝色）和反射信号（橙色）的脉冲无线电。

Looking Beyond the Horizon

UWB已经为40多个垂直领域的产品和服务带来了价值，涵盖消费者、汽车、工业和商业细分市场，从提高工厂和仓库的运营效率、提高工人的安全、为机器人和无人机自动导航提供动力，到为用户提供新形式的用户界面基于位置的消费者。由于其安全的距离限制功能，它还能够安全、免提地进入汽车、前门、家庭和办公室。

UWB has proven to be the only technology able to really help withcontact tracingand social distancing in the fight against COVID-19 as accuracy and reliability are key attributes to designing effective solutions where you need to trust the data.

Unlike other wireless technologies, UWB provides the accuracy that's needed for COVID-19 contact-tracing and social distancing. It can calculate the distance between people with centimeter precision, allowing absolute certainty whether someone was close enough to others to transmit the virus.

With the recent adoption in smartphones, UWB is now on the path to become the next ubiquitous wireless connectivity in our everyday lives – from our homes to our office to public venues. Having UWB in smartphones is an important first step towards mass adoption. But another key ingredient is to guarantee the interoperability between all those devices. The fast-growing consortiumFiRa已重新组合来自半导体，移动，基础设施和消费者空间的50多家公司，正在积极地研究将保证这种互操作性的协议的定义。这将使开发人员可以在各种新方法中使用UWB - 例如室内映射和导航，智能家居应用，车辆访问和控制，增强现实以及移动支付。最终，室内地点的未来真的仅限于开发人员的想象力。

Learn more aboutUWB technology at Qorvo.

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