两通道自适应FIR滤波器组的时域设计

Design of Two-Channel Signal-Adapted FIR Filterbanks in Time Domain

研究了在无完全重构约束情况下两通道自适应FIR滤波器组的时域设计方法。滤波器组没有PR约束时 ,子带编码器的失真由系统失真和量化失真两部分构成 ,对于给定的比特率 ,整体失真的最小化问题是一个无约束非线性规划问题。由于优化问题的非线性 ,设计结果依赖于初始滤波器组的选择。给出了两种初始滤波器组的确定方法和相应的算法 ,并列举了一些设计例子。自适应滤波器组达到了大的编码增益 ,证实了这种方法的有效性。

The time domain design method of two channel signal adapted FIR filterbanks without perfect reconstruction (PR) constraints is investigated in this paper. For subband coders based on filterbanks without PR constraints, the total distortion is composed of two parts: the systematic distortion and quantization distortion. For a given bit rate, the minimization of the total distortion is an unconstrained nonlinear programming problern. Due to its high nonlinearity, the design results greatly depend on the selection of initial filterbanks. Two approaches to select the initial filterbanks and the associated algorithms are given, and several design examples are presented. The obtained signal adapted filterbanks achieve larger subband coding gains than the existing methods, which verifies our the effectiveness of method.