由时频分布引导的四参数子空间匹配追踪算法

为了克服四参数匹配追踪计算量巨大的缺点,本文提出了一种由时频分布引导的四参数子空间匹配追踪算法.该算法由引导时频分布确定chirp原子的时频中心,然后用模板匹配方法搜索原子的尺度和调频率(chirp rate).这样,一个高计算复杂度的四维搜索问题被转化为两个相对简单的二维搜索问题.为有效利用时频分布,每次搜索多个时频原子,这些原子不再相互正交.为此,我们利用最小二乘方法计算信号(或残差信号)在相应子空间上的正交投影.同快速脊追踪算法相比,四参数子空间匹配追踪需要更少的原子逼近信号,对实测语音信号的数值计算也证实了这点.

Four-Parameter Subspace Matching Pursuit Algorithm with the help of time-frequency distribution

In this paper,we propose a novel matching pursuit algorithm,namely four-parameter subspace matching pursuit algo- rithm with the help of the time-frequency distribution.In the algorithm,the time-frequency centers of the chirp atoms are determined from the pilot TF distribution and then the scale factor and chirp rate is estimated by the stencil matching method.In this way,a four-pa- rameter search of high computational complexity is simplified into the two two-parameter searches with low computational complexity.In order to take fun advantage of the pilot TF distribution,we search multiple matching chirp atoms in each iteration and these atoms are not orthogonal with each other any more.Therefore,the LSM algorithm is used to compute the orthogonal projection of the signal or residual signal onto the corresponding subspace spanned by these atoms.Comparing with the fast ridge pursuit,the proposed algorithm requires much less TF atoms to approximate a signal,which is verified by the numerical results to speech signals.