Adaptive calculation of pulse compression filter coefficients for a radar signal
View Patent ↗In a method for adaptive calculation of pulse compression filter coefficients for a received signal in a radar installation, which received signal is evaluated with the aid of a complex pulse compression mismatch filter, a pulse compression filter coefficient set h(t) is calculated for an ideal theoretical received signal s(t) for a pulse compression mismatch filter, such that a pulse compression output signal results with a desired main lobe to side lobe ratio. A transformed set of pulse compression filter coefficients H opt (f) for the complex pulse compression mismatch filter H opt (f) is calculated for a distorted received signal using the following rule: H opt ( f ) = S ( f ) · H ( f ) · S v * ( f ) S v ( f ) 2 where S(f): the Fourier-transform of an undistorted received signal s(t), S v (f): the Fourier-transform of a distorted received signal s v (t), s v *(f): the complex conjugate of S v (f), H(f): the Fourier-transform of the pulse compression mismatch filter h(t).
1. A method for adaptive calculation of pulse compression filter coefficients for a received signal in a radar installation, which received signal is evaluated with the aid of a complex pulse compression mismatch filter, comprising:
determining, using an electronic processor, a pulse compression filter coefficient set h(t) for an ideal theoretical received signal s(t) for a pulse compression mismatch filter, such that a pulse compression output signal results with a desired main-lobe-to-side-lobe ratio; and
determining, using the electronic processor, a transformed set of pulse compression filter coefficients H opt (f) for the complex pulse compression mismatch filter H opt (f) for a distorted received signal, using the following rule:
H
opt
(
f
)
=
S
(
f
)
·
H
(
f
)
·
S
v
*
(
f
)
S
v
(
f
)
2
where
S(f): Fourier-transform of an undistorted received signal s(t),
S v (f): Fourier-transform of a distorted received signal s v (t),
S v *(f): complex conjugate of S v (f),
H(f): Fourier-transform of the pulse compression mismatch filter h(t).
2. The method as claimed in claim 1 , wherein the pulse compression mismatch filter is in the form of a transversal filter.
3. The method as claimed in claim 1 , wherein:
a transmission signal is output from the radar installation; and
during dead time of the radar installation, the transmission signal is input into a reception branch of a radar installation as a signal sample for a distorted received signal; and
after signal preprocessing, the transmission signal is supplied to a component in which a pulse compression filter coefficient matrix H opt (f) is determined for the complex pulse compression mismatch filter.
4. A complex pulse compression mismatch filter comprising:
an input device for receiving a reflected pulse train for a radar system;
an output device which supplies compressed pulses; and
a processor for determining a set of pulse compression filter coefficients for said filter by
i) determining a pulse compression filter coefficient set h(t) for an ideal theoretical received signal s(t) for a pulse compression mismatch filter, such that a pulse compression output signal has a desired main-lobe-to-side-lobe ration; and
ii) determining a transformed set of pulse compression filter coefficients H opt (f) for the complex pulse compression mismatch filter H opt (f) for a distorted received signal, using the following rule:
H
opt
(
f
)
=
S
(
f
)
·
H
(
f
)
·
S
v
*
(
f
)
S
v
(
f
)
2
where
S(f): Fourier-transform of an undistorted received signal s(t),
S v (f): Fourier-transform of a distorted received signal s v (t),
S v *(f): complex conjugate of S v (f),
H(f): Fourier-transform of the pulse compression mismatch filter h(t).