基于USRP的OFDM系统无线运动感知平台研究与实现

发布时间：2018-04-19 11:11

本文选题：穿墙运动感知 + OFDM　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：近些年来,穿墙检测封闭环境中物体的运动情况是一个研究热点。由于OFDM系统具有频谱效率高、带宽扩展性强、抗多径等优点,将其应用于运动感知的传输系统中可以提高检测的准确性。本文研究并实现了采用USRP作为收发设备,基于OFDM系统探测室内物体运动状态的无线运动感知平台。首先,介绍了与实现运动感知平台相关的基本内容。主要包括OFDM系统的基本原理和相关技术,以及检测信号时所使用的无线收发设备——通用软件无线电平台。最后,针对文章要实现的穿墙运动检测提出了所需解决的主要问题。其次,对于实现运动检测所需解决的消除静态干扰和跟踪运动轨迹两大问题给出了解决方案,即无线运动感知平台实施方案。首先对解决这两大问题的前提——获取信道估计值算法进行推导和分析,仿真并验证了LS、DFT、MMSE算法的均方误差性能依次递增。将MIMO检测的迫零迭代算法应用到运动感知平台的消除静态干扰中,消除环境中所有非运动物体的反射信号。然后采用inverse SAR技术,将人的运动模拟成标准阵列天线,利用MUSIC算法实现运动轨迹的跟踪。最后,完成了整个运动感知平台的搭建并给出检测结果。首先采用C++构建了OFDM物理层链路,利用UHD驱动USRP作为射频收发设备,建立了能实现数据正确收发的无线系统。搭建两发一收的检测平台,利用穿墙信号获得室内信息后,采用迫零迭代算法消除静态干扰,利用平滑的MUSIC算法,检测出室内单人和多人的运动轨迹并画出检测图像。
[Abstract]:In recent years, it is a research focus to detect the motion of objects in closed environment.Because the OFDM system has the advantages of high spectral efficiency, strong bandwidth expansibility and anti-multipath, it can improve the accuracy of detection when it is applied to the motion sensing transmission system.This paper studies and implements a wireless motion sensing platform which uses USRP as a transceiver and detects the moving state of indoor objects based on OFDM system.Firstly, the basic contents related to the realization of motion perception platform are introduced.It mainly includes the basic principle and related technology of OFDM system, as well as the wireless transceiver equipment used in signal detection, the general software radio platform.Finally, the main problems that need to be solved are put forward for the motion detection through the wall.Secondly, a solution to the two problems of eliminating static interference and tracking motion trajectory is presented, that is, the implementation scheme of wireless motion sensing platform.Firstly, the presupposition to solve these two problems is deduced and analyzed, and the simulation results show that the mean square error performance of the LSS-DFT / MMSE algorithm increases in turn.The zero-forcing iterative algorithm of MIMO detection is applied to remove static interference from motion sensing platform to eliminate the reflected signals of all non-moving objects in the environment.Then the human motion is simulated into a standard array antenna using inverse SAR technology, and the MUSIC algorithm is used to track the motion trajectory.Finally, the whole motion sensing platform is built and the detection results are given.Firstly, the physical layer link of OFDM is constructed by using C, and the radio frequency transceiver device using UHD to drive USRP is used to establish a wireless system which can realize the correct receiving and sending of data.The detection platform of two sending and one receiving is built. After the indoor information is obtained by the signal through the wall, the zero-forcing iterative algorithm is adopted to eliminate the static interference, and the smooth MUSIC algorithm is used to detect the track of single person and many people in the room and draw out the detection image.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.53

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