【摘要】 根据泛函积分方法研究随机散射通道模型中传递函数的概率分布,通过引入复空间上的散射振幅密度和非Gauss型分布函数,给出概率分布中特征函数的泛函积分表示,借助于散射振幅密度的Shift变换和微扰展开技术推导概率分布矩阵元的修正表达式.这些矩阵元对应的方差和协方差,可分别描述随机变量的涨落和关联效应.另外,当散射振幅密度的关联函数取为Dirac-δ函数形式时,并且振荡指数和外源作用系数确定后,计算修正矩阵元和相关系数的具体数值,讨论这些矩阵元的物理含义和变化趋势,还分析外源作用下随机变量的关联性质.结果表明修正矩阵元均呈振荡变化趋势,Gauss型和非Gauss型传递函数中随机变量可以具有不同的关联趋向,当衰减函数振荡变快时,那么传递函数中随机变量关联程度也将提高.更多还原

【Abstract】 The probability distribution of the transfer function in the random scattering channel model is studied according to the functional integral method. The functional integral representation of the characteristic function in the probability distribution is given by introducing the scattering amplitude density and the non-Gaussian distribution function in the complex space. The modified expressions of the probability distribution matrix element are derived by means of the shift transformation and the perturbation expansion technique.The variance and covariance corresponding to these matrix elements can describe the fluctuation and correlation effect of random variables,respectively. In addition,when the correlation function of scattering amplitude density is taken as the form of Dirac-δ function and the oscillation index and external source action coefficient are determined,the concrete values of the modified matrix elements and the correlation coefficients are calculated by using the numerical method,the physical meaning and change trend of these matrix elements are discussed,and the correlation properties of random variables under the action of external source are also analyzed.更多还原