Ko, Chi-Chung
The power inversion adaptive array
After the brief review on adaptive array processing, three
fairly separate topics on the power inversion adaptive array are
treated in this thesis. The first topic is the behaviour of a narrowband
array using the stochastic gradient descent algorithm,
with the environment assumed to rotate at constant velocity in the
sine domain. Conditions for steady state weight deviations and
output power deterioration from optimal values due to the nonstationary
environment are derived and are then used to determine the
maximum scan rate of a radar side-lobe canceller. The second topic
is the jamming rejection capability of a broadband array using tapped
delay line processing. The results obtained are used for designing
the tap spacing and number of taps of the delay lines as
well as assessing, in terms of the number of variable weights, the
relative advantage of the alternative broadband processing method
using several narrowband array processors. The frequency distortions
at various directions introduced by rejecting the jammers are
also studied qualitatively. The third topic is the convergence
behaviour of the broadband array when the stochastic gradient descent
algorithm is employed. Comparison with the alternative broadband processing method is again given. A simple transformation
pre-processor, independent of the external environment and capable
of improving the convergence behaviour of using tapped delay line
processing, is also derived.
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2018-05-15
https://repository.lboro.ac.uk/articles/thesis/The_power_inversion_adaptive_array/9521654