To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is ...To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is based on a batch back-propagation neural network algorithm by directly minimizing the real magnitude error and phase error from the linear-phase to obtain the filter＇s coefficients. The approach can deal with both the real and complex coefficient FIR digital filters design problems. The main advantage of the proposed design method is the significant reduction in the group delay error. The effectiveness of the proposed method is illustrated with two optimal design examples.展开更多
Based on digital signal processing theory,a novel method of designing optical notch filter is proposed for Mach-Zehnder interferometer with cascaded optical fiber rings coupled structure.The method is simple and effec...Based on digital signal processing theory,a novel method of designing optical notch filter is proposed for Mach-Zehnder interferometer with cascaded optical fiber rings coupled structure.The method is simple and effective,and it can be used to implement the designing of the optical notch filter which has arbitrary number of notch points in one free spectrum range(FSR).A design example of notch filter based on cascaded single-fiber-rings is given.On this basis,an improved cascaded double-fiber-rings structure is presented to eliminate the effect of phase shift caused by the single-fiber-ring structure.This new structure can improve the stability and applicability of system.The change of output intensity spectrum is finally investigated for each design parameter and the tuning characteristics of the notch filter are also discussed.展开更多
基金supported by the Construction S&T Project of Department of Transportation of Sichuan Province(Grant No.2023A02,No.2024A04,No.2020A01)the Sichuan Science and Technology Program(Grant No.2022YFG0141)+3 种基金the Research Project of Sichuan Highway Planning,Survey,Design,and Research Institute Ltd.(Grant No.KYXM2021000049,No.KYXM2022000038,No.KYXM202300056)the National Natural Science Foundation of China(41630640)the National Science Foundation of Innovation Research Group(41521002)the National Natural Science Foundation of China(41790445).
基金supported by the Construction S&T Project of Department of Transportation of Sichuan Province (Grant No.2023A02,No.2024A04,No.2020A01)the Sichuan Science and Technology Program (Grant No.2022YFG0141)+3 种基金the Research Project of Sichuan Highway Planning,Survey,Design,and Research Institute Ltd. (Grant No.KYXM2021000049,KYXM2022000038,No.KYXM2023000056)the National Natural Science Foundation of China (41630640)the National Natural Science Foundation of China (41790445)the National Science Foundation of Innovation Research Group (41521002)。
基金supported by the National Natural Science Foundation of China(6087602250677014)+2 种基金the High-Tech Research and Development Program of China(2006AA04A104)the Hunan Provincial Natural Science Foundation of China (06JJ202407JJ5076).
文摘To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is based on a batch back-propagation neural network algorithm by directly minimizing the real magnitude error and phase error from the linear-phase to obtain the filter＇s coefficients. The approach can deal with both the real and complex coefficient FIR digital filters design problems. The main advantage of the proposed design method is the significant reduction in the group delay error. The effectiveness of the proposed method is illustrated with two optimal design examples.
基金supported by the National Natural Science Foundation of China (No.10804070)the Innovation Program of Shanghai Municipal Education Commission (No.09YZ06)Shanghai Leading Academic Discipline Project (No.S30108)
文摘Based on digital signal processing theory,a novel method of designing optical notch filter is proposed for Mach-Zehnder interferometer with cascaded optical fiber rings coupled structure.The method is simple and effective,and it can be used to implement the designing of the optical notch filter which has arbitrary number of notch points in one free spectrum range(FSR).A design example of notch filter based on cascaded single-fiber-rings is given.On this basis,an improved cascaded double-fiber-rings structure is presented to eliminate the effect of phase shift caused by the single-fiber-ring structure.This new structure can improve the stability and applicability of system.The change of output intensity spectrum is finally investigated for each design parameter and the tuning characteristics of the notch filter are also discussed.
