Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Design of Nonrecursive Digital Filters Using the Ultraspherical Window Function | EURASIP Journal on Applied Signal Processing 2005 12 1910-1922 2005 Hindawi Publishing Corporation Design of Nonrecursive Digital Filters Using the Ultraspherical Window Function Stuart W. A. Bergen Department of Electrical and Computer Engineering University of Victoria P. O. Box 3055 STN CSC Victoria BC Canada V8W 3P6 Email sbergen@ Andreas Antoniou Department of Electrical and Computer Engineering University of Victoria P O. Box 3055 STN CSC Victoria BC Canada V 81V 3P6 Email aantoniou@ Received 13 September 2004 Revised 8 February 2005 Recommended for Publication by Ulrich Heute An efficient method for the design of nonrecursive digital filters using the ultraspherical window function is proposed. Economies in computation are achieved in two ways. First through an efficient formulation ofthe window coefficients the amount of computation required is reduced to a small fraction of that required by standard methods. Second the filter length and the independent window parameters that would be required to achieve prescribed specifications in lowpass highpass bandpass and bandstop filters as well as in digital differentiators and Hilbert transformers are efficiently determined through empirical formulas. Experimental results demonstrate that in many cases the ultraspherical window yields a lower-order filter relative to designs obtained using windows like the Kaiser Dolph-Chebyshev and Saramaki windows. Alternatively for a fixed filter length the ultraspherical window yields reduced passband ripple and increased stopband attenuation relative to those produced when using the alternative windows. Keywords and phrases nonrecursive digital filters FIR filters window functions ultraspherical window digital differentiators Hilbert transformers. 1. INTRODUCTION Window functions or windows for short are time-domain weighting functions that have found widespread usage in signal processing applications such as power spectral estimation beamforming and .
