Parameter Estimation and Cramer-Rao bound in Wideband Bistatic
MIMO Radar System
Li Li
1, a
1
Information Engineering College, Dalian University, China
a
ffsimple@163.com
Keywords: bistatic MIMO radar; parameter estimation; FRFT; Cramér-Rao bound
Abstract. The problem of target localization and parameter estimation in wideband bistatic
Multiple-Input Multiple-Output (MIMO) radar system is considered. In this paper, we use a novel
approach to estimate Doppler stretch and time delay in fractional Fourier transform (FRFT) domain.
We also develop two sub-array models to accurately estimate the direction-of-departure (DOD) and
the direction-of-arrival (DOA). Furthermore, the Cramér-Rao bound for target parameter estimation
is derived and computed in closed form. Parameter estimation performances are evaluated and studied
theoretically and via simulations
Introduction
Multiple-Input Multiple-Output (MIMO) radar [1-2], as a new type of radar, has become a hot
research area owing to its potential advantages. With the development of electronic devices’
manufacture and signal processing techniques, wideband radar has attracted a great deal of interest.
However, these existing methods have certain limitations. Qu [3] estimates time delay and Doppler
stretch for wideband signals based on the wideband ambiguity function. Ma [9] proposes two novel
methods for broadband chirp DOA estimation, These methods obtain good performance for DOA
estimation of wideband signal, however, they did not estimate the Doppler and time delay which are
also very crucial for the determination of the range and velocity of the target in wideband bistatic
MIMO radar. At present, we seldom find the study of joint estimation for Doppler, time delay, DOD
and DOA in wideband bistatic MIMO radar, which should be studied deeply for target tracking and
target localization. So, in this paper, we study parameter estimation of wideband signal model for
multiple targets localization in the context of wideband bistatic MIMO radar.
The Proposed Signal Model
We consider a bistatic MIMO radar system with
closely spaced transmit antennas and
closely
spaced receive antennas.
and
are interelement spacing at the transmitter and the receiver
respectively. For improving the ability of anti-interference, each transmit antenna transmits chirp
signal
( )
2
0 0
q q q q
x t A j f t t
π µ
= + for
.
denotes the DOD and
denotes the DOA.
The received signal
, reflected from
moving targets, can be expressed as
( )
( )
( )
( ) ( )
( )
T
1
L
l l l l l
l
β τ ϕ θ
=
= − +
∑
(1)
where
denotes the Radar Cross-Section,
and
denote the Doppler stretch factor and the time
delay,
( )
( )
( )
( )
( )
( )
1
,...,
l l l l Q l l
a t - τ x a t - τ x a t - τ
=
x , where
denotes the transpose matrix.
( ) ( ) ( )
1
,...,
l l Q l
A A
ϕ ϕ ϕ
=
A and
1
,...,
l l N l
B B
=
B , where
t
exp 2 1 sin
q l l
A j q d
= −
and
r
exp 2 1 sin
n l l
B j n d
= − .
is assumed to be independent, zero-mean Gaussian white
noise with variance
.
Applied Mechanics and Materials Vols 713-715 (2015) pp 651-655 Submitted: 2014-11-07
© (2015) Trans Tech Publications, Switzerland Accepted: 2014-11-08
doi:10.4028/www.scientific.net/AMM.713-715.651 Online: 2015-01-13
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans
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