Increasing resolution and range for i-q linear frequency modulated radar

Patent metadata

Field	Value
Publication number	US-2018329030-A1
Application number	US-201715592617-A
Country	US
Kind code	A1
Filing date	May 11, 2017
Priority date	May 11, 2017
Publication date	Nov 15, 2018
Grant date	—

Abstract

A radar system and method of extending a parameter of a location of a target obtained by radar is disclosed. The system receives an echo signal that is a reflection of a radar source signal from the target. The echo signal is sampled and a peak for the echo signal is objected in frequency space. For a peak that is located at a frequency greater than a Nyquist frequency of the echo signal, the peak is moved to a negative domain of the frequency space and the location of the target is determined using the peak in the negative domain.

First claim

What is claimed is:

1 . A method of extending a parameter of a location of a target obtained by radar, comprising:
receiving an echo signal that is a reflection of a radar source signal from the target; obtaining a peak in a frequency space for the echo signal, wherein the peak is located at a frequency greater than a Nyquist frequency of the echo signal; moving the peak to a negative domain of the frequency space; and determining the location of the target using the peak in the negative domain.

2 . The method of claim 1 , wherein obtaining the peak further comprises performing a Fast Fourier Transform on the echo signal.

3 . The method of claim 1 , wherein the peak is located between the Nyquist frequency and twice the Nyquist frequency.

4 . The method of claim 3 , wherein the negative frequency domain is between a negative of the Nyquist frequency (−f s /2) and zero.

5 . The method of claim 1 , wherein moving the peak further comprises subtracting twice the Nyquist frequency from the frequency of the peak.

6 . The method of claim 1 , further comprising applying an anti-aliasing filter to the frequency space, wherein the anti-aliasing filter has a cut off frequency that is twice the Nyquist frequency.

7 . The method of claim 1 , wherein the parameter is a range of the location, further comprising sampling the echo signal at the Nyquist frequency.

8 . The method of claim 1 , wherein the parameter is a resolution of the location, further comprising sampling the echo signal at half the Nyquist frequency.

9 . The method of claim 1 , further comprising maneuvering a vehicle to avoid the target from the determined location.

10 . A radar system, comprising:
a transmitter configured to generate a radar source signal; a receiver configured to receive an echo signal that is a reflection of the radar source signal from a target; and a processor configured to:
sample the echo signal at a sampling frequency,
obtain a peak in a frequency space for the sampled echo signal, wherein the peak is located at a frequency greater than a Nyquist frequency of the echo signal,
move the peak to a negative frequency domain of the frequency space, and
determine a location of the target using the peak in the negative domain.

11 . The system of claim 11 , wherein the processor obtains the peak by performing a Fast Fourier Transform on the sampled echo signal.

12 . The system of claim 11 , wherein the peak is located in frequency space between the Nyquist frequency and twice the Nyquist frequency.

13 . The system of claim 13 , wherein the negative frequency domain is between a negative of the Nyquist frequency (−f s /2) and zero.

14 . The system of claim 11 , wherein the processor moves the peak by subtracting twice the Nyquist frequency from the frequency of the peak.

15 . The system of claim 11 , wherein the processor applies an anti-aliasing filter having a cut off frequency that is twice the Nyquist frequency to the frequency space.

16 . The system of claim 11 , wherein the parameter is a range of the location and the processor samples the echo signal at the Nyquist frequency.

17 . The system of claim 11 , wherein the parameter is a resolution of the location and the processor samples the echo signal at half the Nyquist frequency.

18 . The system of claim 11 , further comprising a collision-avoidance device that receives the parameter from the radar system and maneuvers the vehicle to avoid the target from the parameter.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Laifenfeld Moshe
• Pokrass Alexander
• Bilik Igal

Classifications

• G01S7/411 Primary

  Identification of targets based on measurements of radar reflectivity (G01S7/415 takes precedence) · CPC title

• G01S13/931

  of land vehicles · CPC title

• G01S2013/9319

  Controlling the accelerator · CPC title

• G01S2013/9318

  Controlling the steering · CPC title

• G01S7/352 Primary

  Receivers · CPC title