31-05-2012, 12:28 PM
Adaptive OFDM Radar for Detecting a Moving Target in Urban Scenarios
[attachment=23661]
INTRODUCTION
Detection and tracking of ground targets in urban environments
are becoming increasingly important in defense applications.
The urban scenario is rich in multipath propagation
generated by multiple reflections, refractions, and scattering
of the radar signal from buildings and other structures. In
addition, the line-of-sight (LOS) propagation path from the
radar to the target may not be available most of the time.
Hence, conventional radar systems, which are designed to
operate mainly in open environments [1], encounter difficulties
in the urban operations. We propose to exploit the
multipath reflections rather than canceling them to improve
the target-detection performance.
PROBLEM DESCRIPTION AND MODELING
In this section, we first introduce the radar signal model
that accounts for the multipath components over multiple
frequencies as well as the Doppler shifts. Then, we discuss
our statistical assumption on the noise and interference.
DETECTION TEST
In this section, we first develop a statistical detection test
for the model presented in Section II. Our goal is to decide
whether a target is present or not in the range cell under
consideration. Then we analytically derive the performance
characteristics of the test.
We construct the decision problem to choose between
two possible hypotheses:
CONCLUSIONS
In this paper, we addressed the problem of detecting a
moving target using an OFDM radar and exploiting multipath
reflections in an urban canyon. We first developed the measurement
model that accounts for the multipath components
generated by the specular reflections as well as Doppler shifts.
We considered a broadband radar transmitting orthogonal
frequency division multiplexing signals. Then, we formulated
the detection problem as a hypothesis test to decide about the
presence of a moving target. We analyzed the performance
of this proposed detector both numerically and analytically.
[attachment=23661]
INTRODUCTION
Detection and tracking of ground targets in urban environments
are becoming increasingly important in defense applications.
The urban scenario is rich in multipath propagation
generated by multiple reflections, refractions, and scattering
of the radar signal from buildings and other structures. In
addition, the line-of-sight (LOS) propagation path from the
radar to the target may not be available most of the time.
Hence, conventional radar systems, which are designed to
operate mainly in open environments [1], encounter difficulties
in the urban operations. We propose to exploit the
multipath reflections rather than canceling them to improve
the target-detection performance.
PROBLEM DESCRIPTION AND MODELING
In this section, we first introduce the radar signal model
that accounts for the multipath components over multiple
frequencies as well as the Doppler shifts. Then, we discuss
our statistical assumption on the noise and interference.
DETECTION TEST
In this section, we first develop a statistical detection test
for the model presented in Section II. Our goal is to decide
whether a target is present or not in the range cell under
consideration. Then we analytically derive the performance
characteristics of the test.
We construct the decision problem to choose between
two possible hypotheses:
CONCLUSIONS
In this paper, we addressed the problem of detecting a
moving target using an OFDM radar and exploiting multipath
reflections in an urban canyon. We first developed the measurement
model that accounts for the multipath components
generated by the specular reflections as well as Doppler shifts.
We considered a broadband radar transmitting orthogonal
frequency division multiplexing signals. Then, we formulated
the detection problem as a hypothesis test to decide about the
presence of a moving target. We analyzed the performance
of this proposed detector both numerically and analytically.