音频ADC中∑-Δ调制器的鲁棒H_∞滤波器设计  

Design of robust H_∞ filter for ∑-Δ modulators in audio ADC

作　　者：王骞[1] 蔡逢煌[1] 王武[1] 王英俊[1] 

机构地区：[1]福州大学电气工程与自动化学院,福建福州350108

出　　处：《中南大学学报（自然科学版）》2013年第S1期82-86,共5页Journal of Central South University:Science and Technology

基　　金：福建省自然科学基金资助项目(2012J01257);福州大学科技发展基金资助项目(2012-XY-3)

摘　　要：在采用∑-Δ调制器结构的音频模数转换系统中,针对调制器中积分器参数不确定性对系统输出性能的影响,提出一种改进型的五阶2-2-1级联∑-Δ调制器,并研究∑-Δ调制器中鲁棒滤波器的设计问题。基于MARKOV区间算法,将不确定性因子间的非线性关系表述为线性区间矩阵,并以线性矩阵不等式给出鲁棒滤波器存在的充分条件。最后采用优化CSD编码设计了鲁棒滤波器。仿真结果表明,鲁棒滤波器比传统滤波器的输出信噪比提高了20 dB,可达到114.5 dB的信噪比和18.72位的精度;该方法具有实现成本低、资源占用少的优点,可应用于音频模数转换器。In the audio analog to digital converter system using sigma-delta modulator structure,an improved fifth-order 2-2-1 cascaded sigma-delta modulator and robust filter was studied to solve the restriction of the uncertainty of integrator parameter to the cascaded sigma-delta modulator.Based on MARKOV interval algorithm,the nonlinear relationship of uncertain factors was transformed into linear interval matrix.A linear matrix inequality approach was developed to obtain the parameters of a robust filter.The robust filter was designed based on method of optimized CSD coding.The results indicate that the robust filter outperformed the nominal filter with an improve signal-to-noise ratio about 20 dB,which achieves a signal-to-noise ratio of 114.5 dB and a resolution of 18.72 bits.The robust filter has the advantage of low cost and little using of resource.This filter is sufficient for the audio analog to digital converter applications.

关 键 词：级联∑-Δ调制器 鲁棒滤波器 不确定性 CSD编码 

分 类 号：TN792[电子电信—电路与系统]