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.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
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)
