为了解决在真实环境下到达时间差(time difference of arrival,TDOA)定位性能评估所面临的测量成本高、不可控干扰因素较多等问题,提出了一种利用传播图论多链路信道仿真来评估TDOA定位系统性能的方法.即采用传播图论的方法生成不同的...为了解决在真实环境下到达时间差(time difference of arrival,TDOA)定位性能评估所面临的测量成本高、不可控干扰因素较多等问题,提出了一种利用传播图论多链路信道仿真来评估TDOA定位系统性能的方法.即采用传播图论的方法生成不同的信道冲激响应,并通过软件无线电装置产生经信道畸变的射频信号,作为多个TDOA传感器的输入,形成一种新型的TDOA定位检测方法.首次将复杂外场采用射频仿真的方式,针对城市环境中的TDOA系统构建4个测试场景,对TDOA系统的定位精度进行检验.仿真结果表明,被测的多链路定位系统在信号带宽不小于200 kHz条件下表现出良好且稳定的性能.此外,本文提出的嵌入衍射机制的图论建模方法,相比传统图论更为有效地提升了TDOA定位误差的仿真准确度.展开更多
基于45 GHz毫米波室内通信测量对木板、镜子以及白铁板的阻挡绕射特性进行了研究.根据阻挡物材料的不同,分别提出三射线和四射线阻挡绕射模型.对12 mm厚的木板、6 mm厚的镜子以及0.35 mm厚的白铁板进行了矩形阻挡绕射测量实验.实验结果...基于45 GHz毫米波室内通信测量对木板、镜子以及白铁板的阻挡绕射特性进行了研究.根据阻挡物材料的不同,分别提出三射线和四射线阻挡绕射模型.对12 mm厚的木板、6 mm厚的镜子以及0.35 mm厚的白铁板进行了矩形阻挡绕射测量实验.实验结果表明,在矩形木板阻挡下45 GHz毫米波的平均传输衰减系数约为-4.28 d B,其衰减测量结果与提出的四射线模型仿真结果平均误差为-0.02 d B.在0.35 mm厚的矩形白铁板阻挡下,45 GHz毫米波的平均传输衰减系数约为-18.2 d B.在镜子远离天线的情况下,面对发射天线时的平均传输衰减比背对发射天线时大1~2 d B,而在镜子靠近天线的情况下,其面对发射天线时测量的结果与白铁板阻挡下的衰减类似.展开更多
A novel multi-dimensional （MD） optical storage was presented, which was realized by utilizing the space between tracks. Based on scalar diffraction theory, the channel bits parameters of the multi-dimensional optica...A novel multi-dimensional （MD） optical storage was presented, which was realized by utilizing the space between tracks. Based on scalar diffraction theory, the channel bits parameters of the multi-dimensional optical storage were optimized, and the linear and nonlinear signals were analyzed accurately. Therefore, the format of the multi-dimensional optical disc was obtained, which makes the detection of readout signal easier. With respect to servo, coding and readout physics parameter of channel, the multi-dimensional optical disc is compatible with traditional disc such as Blu-ray disc （BD）. Also, the novel multi-dimensional optical storage is able to achieve a doubled density and a ten-fold readout data rate compared with traditional optical discs.展开更多
针对雷达目标散射中心GTD(Geometric Theory of Diffraction)模型最大似然估计中存在的高维、非线性、混合参数估计问题,提出一种基于协同粒子群优化算法的参数估计方法.该方法能够同时估计得到散射中心的类型、幅度和位置参数,且对初...针对雷达目标散射中心GTD(Geometric Theory of Diffraction)模型最大似然估计中存在的高维、非线性、混合参数估计问题,提出一种基于协同粒子群优化算法的参数估计方法.该方法能够同时估计得到散射中心的类型、幅度和位置参数,且对初始值不敏感,与基于RELAX的估计方法相比,不需要反复迭代估计,降低了计算复杂度.仿真实验结果表明,该算法能够较准确地估计得到GTD模型的散射中心参数.展开更多
文摘为了解决在真实环境下到达时间差(time difference of arrival,TDOA)定位性能评估所面临的测量成本高、不可控干扰因素较多等问题,提出了一种利用传播图论多链路信道仿真来评估TDOA定位系统性能的方法.即采用传播图论的方法生成不同的信道冲激响应,并通过软件无线电装置产生经信道畸变的射频信号,作为多个TDOA传感器的输入,形成一种新型的TDOA定位检测方法.首次将复杂外场采用射频仿真的方式,针对城市环境中的TDOA系统构建4个测试场景,对TDOA系统的定位精度进行检验.仿真结果表明,被测的多链路定位系统在信号带宽不小于200 kHz条件下表现出良好且稳定的性能.此外,本文提出的嵌入衍射机制的图论建模方法,相比传统图论更为有效地提升了TDOA定位误差的仿真准确度.
文摘基于45 GHz毫米波室内通信测量对木板、镜子以及白铁板的阻挡绕射特性进行了研究.根据阻挡物材料的不同,分别提出三射线和四射线阻挡绕射模型.对12 mm厚的木板、6 mm厚的镜子以及0.35 mm厚的白铁板进行了矩形阻挡绕射测量实验.实验结果表明,在矩形木板阻挡下45 GHz毫米波的平均传输衰减系数约为-4.28 d B,其衰减测量结果与提出的四射线模型仿真结果平均误差为-0.02 d B.在0.35 mm厚的矩形白铁板阻挡下,45 GHz毫米波的平均传输衰减系数约为-18.2 d B.在镜子远离天线的情况下,面对发射天线时的平均传输衰减比背对发射天线时大1~2 d B,而在镜子靠近天线的情况下,其面对发射天线时测量的结果与白铁板阻挡下的衰减类似.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 61475080）.
文摘A novel multi-dimensional （MD） optical storage was presented, which was realized by utilizing the space between tracks. Based on scalar diffraction theory, the channel bits parameters of the multi-dimensional optical storage were optimized, and the linear and nonlinear signals were analyzed accurately. Therefore, the format of the multi-dimensional optical disc was obtained, which makes the detection of readout signal easier. With respect to servo, coding and readout physics parameter of channel, the multi-dimensional optical disc is compatible with traditional disc such as Blu-ray disc （BD）. Also, the novel multi-dimensional optical storage is able to achieve a doubled density and a ten-fold readout data rate compared with traditional optical discs.
文摘针对雷达目标散射中心GTD(Geometric Theory of Diffraction)模型最大似然估计中存在的高维、非线性、混合参数估计问题,提出一种基于协同粒子群优化算法的参数估计方法.该方法能够同时估计得到散射中心的类型、幅度和位置参数,且对初始值不敏感,与基于RELAX的估计方法相比,不需要反复迭代估计,降低了计算复杂度.仿真实验结果表明,该算法能够较准确地估计得到GTD模型的散射中心参数.
