In the forthcoming 5G systems, new technologies, such as amorphous networks and non-orthogonal filter bank multicarriers(FBMC), provide an effective way to accommodate high-rate transmissions. Meanwhile, the prototype...In the forthcoming 5G systems, new technologies, such as amorphous networks and non-orthogonal filter bank multicarriers(FBMC), provide an effective way to accommodate high-rate transmissions. Meanwhile, the prototype filter affects the adjacent channel interference, and therefore is important for FBMC systems. Besides, once the amorphous network is taken into account, the requirement for interference controlmust be much stricter. Accordingly, this paper focuses on the design of prototype filter with better ability of interference controlling, where we exploit the nonlinear phase FIR filter(NLPFF) instead of traditional linear phase FIR filter(LPFF) to achieve more optimization spaces under a small sacrifice of linear phase. In ourdesigns, both the amplitude and phase responsesare handled independently to approach the stopband performance enhancements, in while the nearly perfect reconstruction(NPR) conditionsare relaxed by pre-specified thresholds. Computer simulations confirm the effectiveness of the NLPFF designs, and demonstrate the advantages of the proposed NLPFF in FBMC applications.展开更多
针对不同模态图像存在严重的几何差异和非线性辐射差异(NID)等问题导致的匹配难题,提出了一种结合多尺度特征与局部采样描述的多模态图像配准方法。首先,引入非线性扩散方程构建非线性尺度空间,然后结合相位一致性与ORB(oriented FAST a...针对不同模态图像存在严重的几何差异和非线性辐射差异(NID)等问题导致的匹配难题,提出了一种结合多尺度特征与局部采样描述的多模态图像配准方法。首先,引入非线性扩散方程构建非线性尺度空间,然后结合相位一致性与ORB(oriented FAST and rotated BRIEF)算法获得多尺度的稳定特征点。接着提出了一种旋转不变的双重高斯采样描述符,可以在NID存在的情况下鲁棒地跨越[0°,360°)的旋转差异。最后,引入了一种图像恢复策略。通过初次匹配获得最优的几何变换模型,修正图像间存在的几何差异,再进行二次匹配提升匹配精度。在遥感、医学和计算机视觉等领域的多模态数据集上进行实验,当图像存在尺度、旋转等几何差异时,所提方法均方根误差平均可达到1.5个像素以内,正确匹配率达到98%以上。表明该方法能够克服图像间非线性辐射差异的影响,可以实现高精度配准。展开更多
辐射源系统特有的非线性可用于辐射源指纹识别(radio frequency fingerprinting,RFF)。特别地,基于非线性动力学重构相空间(reconstructed phase space,RPS)的特征对线性信道具有天然优势,且对细微差异更加敏感。然而,该方法在非理想场...辐射源系统特有的非线性可用于辐射源指纹识别(radio frequency fingerprinting,RFF)。特别地,基于非线性动力学重构相空间(reconstructed phase space,RPS)的特征对线性信道具有天然优势,且对细微差异更加敏感。然而,该方法在非理想场景中同样面临着鲁棒性不足的问题。为此,分析非线性动力学基础与其对应的RFF机理,结合实际非理想应用场景完善了相关理论模型;在此基础上,构造相空间K阶状态转移矩阵,提出通过表征K阶状态转移矩阵的特性来提取RFF特征的方法,并通过理论证明其鲁棒性。基于多种实测和仿真数据在随机扰动、多径衰落等场景下进行细致实验,结果表明所提方法特征机理清晰、计算简单,在多种场景下均表现出明显的鲁棒性优势,具有较高的应用价值。展开更多
基金supported by National Natural Science Foundation of China under Grants No.61471322
文摘In the forthcoming 5G systems, new technologies, such as amorphous networks and non-orthogonal filter bank multicarriers(FBMC), provide an effective way to accommodate high-rate transmissions. Meanwhile, the prototype filter affects the adjacent channel interference, and therefore is important for FBMC systems. Besides, once the amorphous network is taken into account, the requirement for interference controlmust be much stricter. Accordingly, this paper focuses on the design of prototype filter with better ability of interference controlling, where we exploit the nonlinear phase FIR filter(NLPFF) instead of traditional linear phase FIR filter(LPFF) to achieve more optimization spaces under a small sacrifice of linear phase. In ourdesigns, both the amplitude and phase responsesare handled independently to approach the stopband performance enhancements, in while the nearly perfect reconstruction(NPR) conditionsare relaxed by pre-specified thresholds. Computer simulations confirm the effectiveness of the NLPFF designs, and demonstrate the advantages of the proposed NLPFF in FBMC applications.
文摘针对不同模态图像存在严重的几何差异和非线性辐射差异(NID)等问题导致的匹配难题,提出了一种结合多尺度特征与局部采样描述的多模态图像配准方法。首先,引入非线性扩散方程构建非线性尺度空间,然后结合相位一致性与ORB(oriented FAST and rotated BRIEF)算法获得多尺度的稳定特征点。接着提出了一种旋转不变的双重高斯采样描述符,可以在NID存在的情况下鲁棒地跨越[0°,360°)的旋转差异。最后,引入了一种图像恢复策略。通过初次匹配获得最优的几何变换模型,修正图像间存在的几何差异,再进行二次匹配提升匹配精度。在遥感、医学和计算机视觉等领域的多模态数据集上进行实验,当图像存在尺度、旋转等几何差异时,所提方法均方根误差平均可达到1.5个像素以内,正确匹配率达到98%以上。表明该方法能够克服图像间非线性辐射差异的影响,可以实现高精度配准。
文摘辐射源系统特有的非线性可用于辐射源指纹识别(radio frequency fingerprinting,RFF)。特别地,基于非线性动力学重构相空间(reconstructed phase space,RPS)的特征对线性信道具有天然优势,且对细微差异更加敏感。然而,该方法在非理想场景中同样面临着鲁棒性不足的问题。为此,分析非线性动力学基础与其对应的RFF机理,结合实际非理想应用场景完善了相关理论模型;在此基础上,构造相空间K阶状态转移矩阵,提出通过表征K阶状态转移矩阵的特性来提取RFF特征的方法,并通过理论证明其鲁棒性。基于多种实测和仿真数据在随机扰动、多径衰落等场景下进行细致实验,结果表明所提方法特征机理清晰、计算简单,在多种场景下均表现出明显的鲁棒性优势,具有较高的应用价值。
