CAJ | 학술논문

模拟误差是制约混合滤波器组信号重构精度的主要原因,如何降低由模拟误差导致的分解滤波器组系数误差成为了首要问题.引入过采样技术,研究在不同过采样率下8通道混合滤波器组的性能,寻找到过采样率最优值约等于7%.在不同模拟误差下对基于过采样的混合滤波器组的性能进行仿真,结果表明,原型结构和双阶型结构的混叠值相近,但后者对模拟误差的敏感度比前者大.信号重构阶段,在最小二乘法的基础上采用频带加权法进行误差校准.在1%模拟误差内,采用7%过采样率的原型混合滤波器组相比无过采样,平均混叠值下降了约50 dB,最大混叠值下降了约94 dB.仿真验证了引入过采样的有效性.
모의오차시제약혼합려파기조신호중구정도적주요원인,여하강저유모의오차도치적분해려파기조계수오차성위료수요문제.인입과채양기술,연구재불동과채양솔하8통도혼합려파기조적성능,심조도과채양솔최우치약등우7%.재불동모의오차하대기우과채양적혼합려파기조적성능진행방진,결과표명,원형결구화쌍계형결구적혼첩치상근,단후자대모의오차적민감도비전자대.신호중구계단,재최소이승법적기출상채용빈대가권법진행오차교준.재1%모의오차내,채용7%과채양솔적원형혼합려파기조상비무과채양,평균혼첩치하강료약50 dB,최대혼첩치하강료약94 dB.방진험증료인입과채양적유효성.
@@@@The resolution of signal perfect reconstruction of hybrid filter bank(HFB)is very sensitive to analog imperfections,how to reduce the analysis filter bank coefficients error caused by the analog imperfections is the primary problem. Oversampling technique is introduced into HFB,the performance of the 8-channel HFB with different oversampling rates is studied,and simulation finds that the optimal value among the oversampling rates is about 7%. The performance of HFB based on the oversampling is studied in terms of sensitivity to analog im-perfections. The simulation results show that the original structure is a better candidate than the two-stage one. Synthesis stage uses frequency band weighting method based on the least squares method for error calibration. Compared with none-oversampling one,the performance of the original HFB with 7% oversampling rate is im-proved,with 45 dB mean aliasing value reduction and 94 dB max aliasing value reduction. Simulation verifies that introducing the oversampling technique to HFB is effective.