Department of Computer Science and Electrical Engineering
Topic: "Parallel Allpass Filters"
Matthew Heaton
(Student Number: 341409964)
Abstract:
This thesis presents a study of the characteristics and advantages of a little known
class of filters called "Parallel Allpass Filters". They rely on controlling the phase of two
parallel allpass sub-filters so that, when added, an overall non-unity magnitude response
is achieved through constructive and destructive interference. A method for decomposing
IIR filters into such an implementation is also presented. To examine the characteristics
and design of these filters, a Matlab Design Toolbox has been written and then used to
examine their properties. It is found that these filters are extremely efficient, and are stable
against many of the problems associated with both FIR and IIR filters. This thesis finishes
with two example implementations. It is concluded that, while they are little known, Parallel
Allpass Filters constitute a worthwhile class of filters that deserve a place within the Signal
Processing Industry.
Complete Thesis:
thesis.pdf
Additional material:
Toolbox
Test Code
Example Implementation
Miscellaneous Files
Conference Paper:
This paper investigates the use of Parallel Allpass Filters
for the detection and reconstruction of low-voltage Ripple Control
Signals from power lines, the motivation being they are a very
efficient and stable class of digital filter.
Results of a Matlab simulation are presented to demonstrate
the filter performance and it is concluded that, with more work,
Parallel Allpass Filters would be suitable for the detection of
such control signals.
Conference Paper
About the Author
Dept of Computer Science and Electrical
Engineering / Matthew Heaton
/ heaton_matthew@hotmail.com
last mod 15/10/1999