摘要
为建立对不同测流技术和算法之间比较的标准,针对窄带多普勒测流技术估计方差下界展开理论推导和信号仿真。针对随机过程中的参量评价问题,通过对随机过程正进行交级数分解,在观测向量空间内得到联合概率密度,计算观测向量的似然函数,进而对其统计特性讨论,得到Fisher信息矩阵和克拉美罗下界。此外,建立散射仿真信号模型,将克拉美罗下界与仿真信号方差进行对比,观察其随信噪比的变化规律。研究结果表明虽然在理论上计算的克拉美罗下界在实际测量中不能达到,但可以作为不同技术和算法的比较标准,以及评价不同波形参数对系统性能的影响。
Aiming at the lower bound of speed estimation variance of the narrowband Doppler velocity measurement technology, theoretical derivation and signal simulation to establish a standard for the comparisons between different techniques and algorithms are made. To evaluate the parameters of random process, the decomposition method of or- thogonal series for random process is used, and the joint probability density can be obtained in the observation vector space for the likelihood function calculation of observation vector. Statistical characteristics for getting the Fisher in- formation matrix and the Cramer-Rao lower bound are discussed. In addition, the scattering signal simulation model is used to compare the Cramer-Rao lower bound with the variance of the simulation signal. The lower bound of Cra- mer-Rao is calculated theoretically.
出处
《声学技术》
CSCD
2013年第2期96-100,共5页
Technical Acoustics
