Digital filters are an important part of Digital Signal Processing (DSP), which plays
vital roles within the modern world, but their design is a complex task requiring a great
deal of specialised knowledge. An analysis of this design process is presented, which
identifies opportunities for the application of optimisation.
The Genetic Algorithm (GA) and Simulated Annealing are problem-independent
and increasingly popular optimisation techniques. They do not require detailed prior
knowledge of the nature of a problem, and are unaffected by a discontinuous search
space, unlike traditional methods such as calculus and hill-climbing.
Potential applications of these techniques to the filter design process are discussed,
and presented with practical results. Investigations into the design of Frequency Sampling
(FS) Finite Impulse Response (FIR) filters using a hybrid GA/hill-climber proved
especially successful, improving on published results. An analysis of the search space
for FS filters provided useful information on the performance of the optimisation technique.
The ability of the GA to trade off a filter's performance with respect to several design
criteria simultaneously, without intervention by the designer, is also investigated.
Methods of simplifying the design process by using this technique are presented, together
with an analysis of the difficulty of the non-linear FIR filter design problem from
a GA perspective. This gave an insight into the fundamental nature of the optimisation
problem, and also suggested future improvements.
The results gained from these investigations allowed the framework for a potential
'intelligent' filter design system to be proposed, in which embedded expert knowledge,
Artificial Intelligence techniques and traditional design methods work together. This
could deliver a single tool capable of designing a wide range of filters with minimal
human intervention, and of proposing solutions to incomplete problems. It could also
provide the basis for the development of tools for other areas of DSP system design.
Date of Award | 2001 |
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Original language | English |
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Awarding Institution | |
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NATURAL ALGORITHMS IN DIGITAL FILTER DESIGN
PENBERTHY HARRIS, S. (Author). 2001
Student thesis: PhD