Let $\{X_n: n\in \N\}$ be a linear process with density function $f(x)\in L^2(\R)$. We study wavelet density estimation of $f(x)$. Under some regular conditions on the characteristic function of innovations, we achieve, based on the number of nonzero coefficients in the linear process, the minimax optimal convergence rate of the integrated mean squared error of density estimation. Considered wavelets have compact support and are twice continuously differentiable. The number of vanishing moments of mother wavelet is proportional to the number of nonzero coefficients in the linear process and to the rate of decay of characteristic function of innovations. Theoretical results are illustrated by simulation studies with innovations following Gaussian, Cauchy and chi-squared distributions.
翻译:Let $X_n: n\n\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\L§L§2\\\R)$的密度函数是一个线性过程。我们研究波浪密度估计值为$f(x)\\\\(x)$。在某些关于创新的特性功能的常规条件下,我们根据线性过程中的非零系数的数量,实现了综合平均密度估计正方差的最小最大最佳趋同率。 认为的波子有紧凑的支撑, 并且可以连续两次区别。 母波子的消失时数与线性过程中的非零系数的数量以及创新特性的衰减率成成正比。 理论结果通过模拟研究, 在高斯、 粗调和奇夸德分布后进行创新来说明。