Reflected wave power estimation device in a radar signal processor

• US 7,486,230 B2
• Filed: 11/29/2006
• Issued: 02/03/2009
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Yamano, Chiharu, Natsume, Kazuma, Takano, Gaku, Miyake, Yasuyuki
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): GALT, CASSI J
• Application Number:
  US11/605,993
• Publication Number:
  US 20070120730A1
• Time in Patent Office: 797 Days
• Field of Search: 342/189, 342 70- 72, 342147-158, 342/175, 342/195
• US Class Current: 342/189
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 3/74 Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14

Abstract

A radar signal processor has observation means for outputting a predetermined observation signal from a reflected wave, means for extracting an observation signal component concerning a target from the observation signal, means for computing a sample correlation matrix showing a correlation characteristic between the observation means from the observation signal components, means for estimating power of the reflected wave from the sample correlation matrix, and an array response matrix which is comprised of response vectors of the reflected waves. When estimating the power, an adjacent azimuth array response matrix having only the reflected waves of a predetermined arrival direction which power is to be estimated and the reflected waves of an azimuth adjacent to the reflected wave as elements is determined so as to estimate the power of the reflected wave.

Claims

1. A reflected wave power estimation device for a radar signal processor, comprising:

two or more observation means, each observation means having an array element for catching a reflected wave from a target and for outputting a predetermined observation signal from said caught reflected wave;

observation signal component extracting means for extracting an observation signal component concerning said target from said observation signals outputted from each said observation means;

sample correlation matrix computing means for computing a sample correlation matrix showing a correlation characteristic between said observation means, said sample correlation matrix being a sample value of a correlation matrix from said extracted observation signal components corresponding to said respective observation means; and

power estimating means for estimating power of a reflected wave in a predetermined arrival direction from said sample correlation matrix, an array response matrix which is computed on the basis of arrival directions of said caught reflected waves, said array response matrix being comprised of response vectors of said caught reflected waves and an observation noise power given in advance, eliminating an influence of said reflected waves on said reflected wave in said predetermined arrival direction, and for outputting the estimated power outside as a reflected power estimation value;

said power estimating means having adjacent azimuth array response matrix computing means for selecting said reflected wave in said predetermined arrival direction and a reflected wave in an azimuth adjacent to said predetermined arrival direction and for computing and determining said array response matrix as an adjacent azimuth array response matrix, said adjacent azimuth array response matrix having only said reflected wave of said predetermined arrival direction and said reflected wave in said azimuth adjacent to said predetermined arrival direction as elements;

whereby said power estimating means estimates power of said reflected wave in said predetermined arrival direction on the basis of said adjacent azimuth array response matrix computed by said adjacent azimuth array response matrix computing means.

2. The reflected wave power estimation device according to claim 1, wherein said adjacent azimuth array response matrix computing means has adjacent reflected wave selecting means for selecting predetermined number of reflected waves in order of adjacency of said reflected wave in said predetermined arrival direction.

3. The reflected wave power estimation device according to claim 1, wherein said adjacent azimuth array response matrix computing means has adjacent reflected wave selecting means for selecting said reflected waves which exist within a predetermined azimuth difference with respect to said reflected wave in said predetermined arrival direction.

4. The reflected wave power estimation device according to claim 1, wherein said adjacent azimuth array response matrix computing means has adjacent reflected wave selecting means for selecting said reflected waves, meeting such a condition that an inner product between said array response vectors of said reflected wave to be selected and said reflected wave in said predetermined arrival direction is a predetermined value or more.

5. The reflected wave power estimation device according to claim 1, further comprising reflected wave grouping means for classifying said reflected waves into two or more groups from said arrival directions of said caught reflected waves, each group being comprised of said reflected waves which exist within a difference of said azimuths adjacent to each other, wherein said adjacent azimuth array response matrix computing means computes and determines said adjacent azimuth array response matrix from only said reflected waves comprising said group for each said group which has been classified by said reflected wave grouping means, whereby estimating powers of said reflected waves belonging to said group for each of said two or more groups.

6. A reflected wave power estimation device for a radar signal processor comprising:

two or more observation means, each observation means adapted to catch a reflected wave from a target and output a predetermined observation signal based on said caught reflected wave;

observation signal component extracting means for extracting an observation signal component relating to said target from said observation signals;

sample correlation matrix computing means for computing a sample correlation matrix based on a sample value of a correlation matrix from said extracted observation signal components;

power estimating means for estimating power of a reflected wave in a predetermined arrival direction from said sample correlation matrix, an array response matrix which is computed on the basis of arrival directions of said caught reflected waves, said array response matrix comprising response vectors of said caught reflected waves and an observation noise power given in advance, eliminating influence of said reflected waves on said reflected wave in said predetermined arrival direction;

said power estimating means having adjacent azimuth array response matrix computing means for selecting said reflected wave in said predetermined arrival direction and a reflected wave in an azimuth adjacent to said predetermined arrival direction and for computing said array response matrix as an adjacent azimuth array response matrix, said adjacent azimuth array response matrix having only said reflected wave of said predetermined arrival direction and said reflected wave in said azimuth adjacent to said predetermined arrival direction as elements; and

whereby said power estimating means estimates power of said reflected wave in said predetermined arrival direction on the basis of said adjacent azimuth array response matrix computed by said adjacent azimuth array response matrix computing means.