Adaptive digital notch filtering
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Authors
Rangarao, Kaluri Venkata
Subjects
filtering
signal processing
estimation
spectrum estimation
identification notch filtering
signal processing
estimation
spectrum estimation
identification notch filtering
Advisors
Soderstrand, Michael A.
Loomis, Herschel H.
Date of Issue
1991-09
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The problem of narrow band interference while transmitting broad-band signals
like Direct Sequence Spread Spectrum is a common source of problems in Electronic
Warfare. This can occur either due to intentional jamming or due to unavoidable
signal sources present in the vicinity of the receiver. Lack of improper information
on these narrow band interferers makes it difficult to cancel them.
In this thesis the above problem is addressed by using an adaptive notch filtering
technique. Before adopting such a technique other methods like the Least Square
Estimator and the Maximum Likelihood Estimator were explored. However the Kwan
and Martin adaptive notch filter structure was found both relevant and suitable for
the problem of interest. The Kwan and Martin method has the difficulty of increasing
hardware complexity with number of notches. This makes it difficult to implement
in real time. A new algorithm was developed for the purpose of implementing the
structure in real-time. This new algorithm offers the same performance at reduced
hardware complexity. This algorithm was simulated and the results were presented. A
hardware feasibility is discussed by proposing a simple structure based upon existing commercial signal processing chips.
Type
Thesis
Description
Series/Report No
Department
Systems Engineering (SE) [Electronic Warfare]
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
92 p.;28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.