多特征加权指数熵在光斑中心定位中的应用

激光光斑中心检测是视觉测量中常用的关键技术,检测算法的优劣直接影响了测量的精度。针对现有光斑定位算法存在定位精度低、抗干扰能力差等问题,提出一种改进的激光光斑中心定位算法。该算法在Shannon熵的基础上引入指数熵,并根据光斑图像特征选取类内离散度最小和灰度对比度最大对指数熵进行加权处理,将使加权指数熵值最大时的灰度值作为阈值对光斑图像进行阈值分割,由此消除噪声干扰,最后由质心法进行光斑中心定位。实验表明,在兼顾稳定性的同时,与传统阈值分割方法相比,光斑中心定位误差降低了22%以上。

Robust Digital Non-Linear Self-Interference Cancellation in Full Duplex Radios with Maximum Correntropy Criterion

Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference （SI）. We first analyze the multiple noises in the full duplex radio system and model such noises as an α - stable distribution. Then we formulate a novel non-Gaussian SI problem. Under the maximum correntropy criterion （MCC）, a robust digital non-linear self-interference cancellation algorithm is proposed for the SI channel estimation. A gradient descent based algorithm is derived to search the optimal solution. Simulation results show that the proposed algorithm can achieve a smaller estimation error and a higher pseudo signal to interference plus noise ratio （PSINR） than the well-known least mean square （LMS） algorithm and least square （LS） algorithm.

ADPTIVE INTERFERENCE CANCELER BASED ON FOURTH ORDER CUMULANT

An adaptive interference cancler algorithm based on fourth-order cumulant is proposed to overcome the fault of conventional autocorrelation-based Least Mean Square (LMS)algorithm which cannot suppress the correlated Gaussian noises. The recursive formulation of the proposed algorithm is given to reduce its computational complexity. The simulation results are presented to demonstrate the effectiveness of this novel approach.

基于小波消噪的EMD模型在GPS振动信号处理中的应用

经验模式分解和小波分解是当前有效处理非平稳信号的两种时频分析方法,它们各具有其优缺点,适用于不同的应用。从对GPS振动信号的预处理、时域和频域处理入手,结果分析表明,对GPS振动信号先进行小波滤波消除随机噪声的干扰,再应用经验模式分解更有利于变形特征信息的分离和提取,提取的信号与振动平台记录数据更加吻合。