提出了一种快速求解离散Gabor变换分析窗的方法.首先选择一个合适的基函数,同给定的综合窗函数构造一个可逆的块循环矩阵,然后根据块循环矩阵特点,利用快速离散傅里叶变换求解块循环矩阵的逆,最后采用基于块时间递归的并行格型结构来求解分析窗.本文证明了此算法获得的窗函数与给定的综合窗满足双正交关系.实验结果表明,本文算法能快速求解分析窗,相比基于最小范数求解方法,本文提出的算法明显降低了分析窗的计算复杂度.
We present a general approach to compute the analysis window for a given synthesis window in discrete Gabor transform.An auxiliary window is carefully selected and combined with synthesis window to construct a nonsingular block-circulant matrix.We then use fast discrete Fourier transform to compute the inverse of the block-circulant matrix.Since the inverse of the matrix also has block-circulant characteristic,a parallel lattice structures of block time-recursive are thereafter derived to compute the analysis window by exploiting the block structure of the matrices.Compared with the minimum norm solution,the proposed algorithm decreases more computational cost.Experimental results show that the present method is very effective to get a general analysis window.