Adaptive Radiolocation for Mobile Sensor Networks

无线电、传感器、致动器和嵌入式计算技术的进步使得无线传感网络得以激增。这些网络为看似无限的应用程序集提供了一种经济实惠的分布式传感方式。精确定位是许多传感器应用的关键使能器，包括监视网络、机器人传感器、无线自组织传感器网络中基于位置的路由、智能空间和由移动的传感器进行的环境监测。虽然GPS可以潜在地提供精确的定位，但所需接收器的复杂性对于廉价的传感器节点来说可能过于昂贵。 此外，GPS信号非常微弱，在建筑物内或茂密的树叶下定位可能不可靠。GPS定位的这些缺点已经导致对用于无线传感器系统的无GPS分布式无线电定位方法的兴趣增加。该项目的重点是技术GPS无合作无线电定位使用的到达时间在ISM波段的无线电（例如802.11b）有许多问题，必须解决的自适应无线电定位传感器网络。如果多个传感器同时发送应答，则会发生多址干扰。多径的存在会模糊和干扰到达时间的正确估计，从而导致距离误差。RF功率放大器是一个主要的能源消耗，因此定位估计必须以最少的通信。 该项目通过以下方式解决这些问题：1）分析和开发多用户估计算法，该算法可以联合估计来自多个传感器的到达时间（TOA）。 2)创建可重新配置的计算核心，为嵌入式系统提供自适应无线电定位平台。该核心将被设计为实现不同系统参数之间的权衡，包括功率/能量、延迟和定位算法的准确性。 3)传感器网络分布式估计新算法的发展。 4)在2.4 GHz ISM频段工作的试验台上实现合作无线电定位算法。 5)无线电定位网络的天线阵设计和传感算法

Advances in radios, sensors, actuators and embedded computing technology have enabled a proliferation of wireless sensing networks. These networks offer an affordable way of performing distributed sensing for a seemingly unbounded set of applications. Accurate positioning is a key enabler for many sensor applications including surveillance networks, robotic sensors, location-based routing in wireless ad-hoc sensor networks, smart spaces and environmental monitoring by mobile sensors. Although GPS can potentially provide accurate positioning, the complexity of the required receivers may be too costly for inexpensive sensor nodes. Furthermore, the GPS signal is extremely weak and positioning can be unreliable inside buildings or under dense foliage. These drawbacks to GPS positioning have led to increasing interest in GPS-less distributed radiolocation methods for wireless sensor systems. This project focuses on techniques GPS-less cooperative radiolocation using time-of-arrival over ISM-band radios (e.g. 802.11b)There are numerous problems that must be solved for adaptive radiolocation in sensor networks. Multiaccess interference occurs if multiple sensors transmit acknowledgements at the same time. The presence of multipath can obscure and interfere with correct estimation of the time-of-arrival causing range errors. The RF power amplifier is a major energy consumer; therefore positioning estimates must be made with minimal communication. The project addresses these problems through: 1) Analysis and development of multiuser estimation algorithms that can jointly estimate times of arrival (TOAs) from multiple sensors. 2) Creation of a reconfigurable computational core, which enables an adaptive radiolocation platform for embedded systems. The core will be designed to enable tradeoffs between different system parameters, including power/energy, latency and accuracy of the positioning algorithms. 3) Development of new distributed estimation algorithms for sensor networks. 4) Implementation of cooperative radiolocation algorithms in a testbed operating in the 2.4 GHz ISM band. 5) Design of antenna arrays and sensing algorithms for the radiolocation network