多信道压缩采样实现多维射频层析成像的理论与方法研究

Radio tomographic imaging (RTI) is a new sensing method, which can work in some situations where the traditional visual imaging can’t. Because of its distinctive features and advantages, RTI has attracted the attention of many researchers. Currently, the study in this field is at the beginning. Motivated by low imaging accuracy caused by multi-path effect and the changing environments, the proposal will study on multidimensional RTI and multi-channel sampling based on compressive sensing, and it will focus on, 1) radio tomography imaging sensing model; 2) methods of wireless links RSS measurements on multi-channel and pre-processing; 3) compressive sampling model and reconstruction algorithm of multidimensional RTI. With the support of the RF shadow fading model, RSS signals of multi-channel, three-dimensional imaging based on many plane imaging, the proposal will improve the imaging precision. The proposal will also ensure the imaging efficiency by using closed loop feedback measurements. While the results of the project will be a novel yet practical solution for three-dimensional RTI based on multi-channel measurements, it will also substantially contribute to the widespread development of the compressive sensing technologies. The studies of the project will have momentously practical and theoretical significances in several applications including intelligent monitoring, public security, medical monitoring, rescue missions, hazard environments surveying and monitoring so on.

射频层析成像是与视觉成像互补的一种新感知方法，因其鲜明的特点和优势，引起了许多研究者的关注，目前，国内在该方面的研究尚属起步阶段。本课题面对射频层析成像受环境变化、多径效应影响而成像精度不高的难点，拟研究多信道压缩采样实现多维射频层析成像的理论与方法，具体研究内容包括：1)射频层析成像传感模型；2)多信道无线链路RSS测量与预处理方法；3)压缩采样模型和多维图像重构算法。本项目从射频阴影衰落模型、多信道信号利用、多平面拟合三维立体成像三个方面提高成像精度，以压缩传感理论指导的闭环反馈测量方法保证成像效率。此方面的研究，既是对射频层析成像方法在多信道测量、多维成像方面的突破发展，也是对压缩感知理论应用的拓展，有重要的学术意义，在智能监控、公共安全、医疗监护、灾害搜救和危险环境勘测等领域有广泛的应用前景。

基于射频接收信号的感知是一种无需传感器的新型感知方法，该方法因只需精简功能的嵌入式设备而成本低廉、因无需感知对象携带任何设备而不会对感知对象带来不便和负担、因无需拍照录像而不会涉及感知对象的隐私，因这些鲜明的特点和优势，近年成为无线感知领域的一个研究热点。本基金项目重点研究了基于射频接收信号强度的智能感知模型和方法，取得的重要成果包括：1）射频接收信号强度（RSS）的测量与预处理方法，设计生产了三种具有不同特点的RSS信号采集硬件平台，利用小波变换对RSS信号进行预处理；2）构建了面向人流量监测的感知模型，并通过实验验证了模型的可靠和有效性；3）研究了基于接收信号强度的人流量监测的算法，达到了95%以上的人流量监测准确率；4）提出了一种基于无线射频链路交点聚类的目标被动定位追踪方法。5）构建了基于接收信号强度的人体摔倒监测模型。该项目的研究特别是在人流量监测方面取得的成果，一方面既是对无线智能感知理论的深入和拓展，另一方面在智慧城市、智能化景区、智能监控、公共安全、数字楼宇等需要监测或引导人流量的场合也有广泛的应用前景。