Unified Design Procedure for Digital Filters in the Complex Domain
Mr. Worayot Lertniphonphun
Center for Signal and Image Processing
Georgia Institute of Technology
Atlanta, GA 30332-0250
Friday, July 13th, 2:00 PM, ENS 302
worayot@ece.gatech.edu
General
Remez Algorithm in Matlab
Abstract
Digital filter design as a constrained norm problem is studied with
the intent of producing a unified design algorithm for all types of
filters-- FIR, IIR and 2-D FIR-- with complex specifications. The
design problem is treated as an ``Approximation'' or ``Optimization''
problem where the theory and design techniques are developed. A
general filter design norm is proposed to allow easy trade-offs
between the relative importance of error energy and worst-case error.
The Chebyshev, least-squares, and constrained least-squares problems
become special cases because this norm uses a convex combination of
the least-squares norm and the Chebyshev norm.
The primary benefit of this new problem formulation is that a single
efficient multiple exchange algorithm (similar to Remez) has been
developed to cover all the different filter types for magnitude and
phase approximation. In the new algorithm, a small subproblem is
formed at each step and is solved with an iterative reweighted least
squares (IRLS) technique that can handle the design of complex filters
easily.
Biography
Worayot Lertniphophun was born in Bangkok, Thailand, on October 21,
1974. He attended Chulalongkorn University, Bangkok, Thailand, where he
received the Bachelor of Engineering degree in Electrical Engineering in
May 1995. In winter of 1997, he went for graduate studies in Digital
Signal Processing and Communications at Georgia Institute of Technology,
Atlanta, Georgia. He received the M.S. degree in June 1998. He received
CSIP Outstanding Research Award in Spring of 2001 and he won the IEEE
signal processing society's Mahkual's Challenge in May, 2001. His
research interests include Synthetic Aperture Radar (SAR), Digital
Filter Design, Mathematical Optimization, and Digital Communications.
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