Device for computing a sliding and nonrecursive discrete Fourier transform and its application to a radar system
First Claim
1. A device for computing a sliding discrete Fourier transform in a time window of duration T for producing an output representing at least one component (Xkm+1) of said transform from N samples (xm+N) of an input signal whose transform is to be computed, wherein said computing device has at least one stage (Ek) for receiving samples and comprising complex rotation operator means as well as adding and/or subtracting means and delay circuits for delivering said component (Xkm+1) defined by
with
exp {j·
2π
·
(m+1·
k/N)} (1)
space="preserve" listing-type="equation">X'"'"'.sub.k.sup.m+1 =X'"'"'.sub.k.sup.m +x'"'"'.sub.m+N -x'"'"'.sub.m (
2)
space="preserve" listing-type="equation">x'"'"'.sub.m =x.sub.m+N ·
exp {-j·
2π
·
(m·
k/N)} (3)where k is the stage index and m is the window index.
1 Assignment
0 Petitions
Accused Products
Abstract
A device for computing a nonrecursive and sliding discrete Fourier transform as applicable in particular to processing of a pulse compression radar signal has N identical and parallel stages (Ek) for receiving in each case samples of the input signal (em+N). Each stage comprises two complex rotation operators, two adder-subtracters and two delay circuits and delivers a signal Xkm+1 obtained from the following equations: ##EQU1##
50 Citations
7 Claims
- 1. A device for computing a sliding discrete Fourier transform in a time window of duration T for producing an output representing at least one component (Xkm+1) of said transform from N samples (xm+N) of an input signal whose transform is to be computed, wherein said computing device has at least one stage (Ek) for receiving samples and comprising complex rotation operator means as well as adding and/or subtracting means and delay circuits for delivering said component (Xkm+1) defined by
- space="preserve" listing-type="equation">X.sub.k.sup.m+1 =X'"'"'.sub.k.sup.m+1 ·
exp {j·
2π
·
(m+1·
k/N)} (1)
with
space="preserve" listing-type="equation">X'"'"'.sub.k.sup.m+1 =X'"'"'.sub.k.sup.m +x'"'"'.sub.m+N -x'"'"'.sub.m (
2)
space="preserve" listing-type="equation">x'"'"'.sub.m =x.sub.m+N ·
exp {-j·
2π
·
(m·
k/N)} (3)where k is the stage index and m is the window index. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- space="preserve" listing-type="equation">X.sub.k.sup.m+1 =X'"'"'.sub.k.sup.m+1 ·
Specification