Radar signal processor

• US 20070120730A1
• Filed: 11/29/2006
• Published: 05/31/2007
• 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
• Granted Patent: US 7,486,230 B2
• Time in Patent Office: Days
• US Class Current: 342/70
• 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 means for outputting a predetermined observation signal from a reflected wave caught by an array element, 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 which is a sample value of a correlation matrix 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, and means for selecting the reflected wave in a predetermined arrival direction power of which is to be estimated and a reflected wave in an azimuth adjacent to the arrival direction of the reflected wave and for computing and determining the array response matrix as an adjacent azimuth array response matrix, having only these reflected waves as elements in order to estimate the power of the reflected wave on the basis of the adjacent azimuth array response matrix.

Claims

1. 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 reflected wave caught by said array element;

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 which is a sample value of a correlation matrix from said observation signal components corresponding to said respective observation means, which have been extracted by said observation signal component extracting means; and

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

said power estimating means having adjacent azimuth array response matrix computing means for selecting said reflected wave in said predetermined arrival direction power of which is to be estimated and a reflected wave in an azimuth adjacent to said arrival direction of said reflected wave 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 an azimuth adjacent to said arrival direction of said reflected wave 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 radar signal processor 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 power of which is to be estimated when selecting said reflected waves in an azimuth adjacent to said arrival direction of said reflected wave power of which is to be estimated, and said adjacent azimuth array response matrix computing means computes and determines said adjacent azimuth array response matrix which has only said reflected wave power of which is to be estimated and said reflected wave selected by said adjacent reflected wave selecting means as elements.

3. The radar signal processor 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 power of which is to be estimated when selecting said reflected wave in an azimuth adjacent to said arrival direction of reflected wave power of which is to be estimated, and said adjacent azimuth array response matrix computing means computes and determines said adjacent azimuth array response matrix which has only said reflected wave power of which is to be estimated and said reflected wave selected by said adjacent reflected wave selecting means as elements.

4. The radar signal processor according to claim 1, wherein said adjacent azimuth array response matrix computing means has adjacent reflected wave selecting means for selecting said reflected wave, meeting such a condition that an inner product between said array response vectors of said reflected wave to be selected and said reflected wave power of which is to be estimated is a predetermined value or more when selecting said reflected waves in an azimuth adjacent to said arrival direction of reflected wave power of which is to be estimated, and said adjacent azimuth array response matrix computing means computes and determines said adjacent azimuth array response matrix which has only said reflected wave power of which is to be estimated and said reflected wave selected by said adjacent reflected wave selecting means as elements.

5. The radar signal processor 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.