S.M. Jesus sjesus@ualg.pt
SiPLAB-FCT, Universidade do Algarve
Faro, Portugal
Comments: download pdf
file
Ref.: in New Acoustics Selected Topics,
Ed.
Ranz-Guerra and GAllego - Juarez, pp.139-152, CSIC, Madrid
(España),
ISBN 84-00-08111-0, 2003.
Abstract : Model-based correlators are in nowdays widely used
in
disciplines such ascommunications and underwater acoustics. These class
of
methods generally make strong assumptions on the data underlying
physical
model and develop dedicated processors that fully exploit the model
structure.
When the assumed model is a good description of the data, these methods
achieve
very high quality results since, in the mismatch free case, they are
optimal
for the single signal in white noise scenario. However, in presence of
model
mismatch this result is degraded. This paper presents a theoretical
study
that addresses the optimality of model-based correlators when compared
with
straight correlators in a model mismatch situation. It is shown that
model-based
correlators can suffer severe degradation in relatively mild mismatch
scenarios
and - more importantly - in that case model-based correlators are
outperformed
by simple signal correlators. The theory is supported by a few
realistic
examples drawn from underwater acoustics.