Radar signal processing method and apparatus for compensating for in-phase/quadrature-phase (I/Q) imbalance

Patent metadata

Field	Value
Publication number	US-10061014-B2
Application number	US-201514822729-A
Country	US
Kind code	B2
Filing date	Aug 10, 2015
Priority date	Nov 18, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

Provided is a radar signal processing method and apparatus for compensating for an in-phase/quadrature-phase (I/Q) imbalance, the method including extracting a real part of a radar signal in which an I/Q imbalance occurs through a conversion of an in-phase (I) channel signal of the radar signal, extracting an imaginary part of the radar signal through a conversion of a quadrature-phase (Q) channel signal of the radar signal, extracting an error due to the I/Q imbalance based on the real part and the imaginary part, and outputting a correction signal obtained by compensating for the I/Q imbalance of the radar signal based on the error.

First claim

What is claimed is:

1. A radar signal processing method comprising:
receiving a radar signal reflected from an object;
extracting a real part of the radar signal in which an in-phase/quadrature-phase (I/Q) imbalance occurs through a conversion of an in-phase (I) channel signal of the radar signal, wherein the real part includes an I channel and a Q channel;
extracting an imaginary part of the radar signal through a conversion of a quadrature-phase (Q) channel signal of the radar signal, wherein the imaginary part includes an I channel and a Q channel;
extracting an error due to the I/Q imbalance based on multiplying a complex conjugate of the I channel and the Q channel of the real part, and the I channel and the Q channel of the imaginary part;
outputting a correction signal obtained by compensating for the I/Q imbalance of the radar signal based on the error; and
detecting the object from which the radar signal is reflected based on the correction signal.

2. The method of claim 1 , wherein the extracting of the real part comprises:
performing a discrete Fourier transform (DFT) on the I channel signal;
determining a spectrum of the I channel signal based on a DFT result of the I channel signal; and
extracting the real part based on an inverse DFT result of the spectrum of the I channel signal.

3. The method of claim 1 , wherein the extracting of the imaginary part comprises:
performing a DFT on the Q channel signal;
determining a spectrum of the Q channel signal based on a DFT result of the Q channel signal; and
extracting the imaginary part based on an inverse DFT result of the spectrum of the Q channel signal.

4. The method of claim 1 , wherein the outputting comprises:
outputting a Q channel of the correction signal based on the error and the imaginary part; and
outputting an I channel of the correction signal based on the in-phase (I) channel signal of the radar signal.

5. The method of claim 1 , wherein the radar signal is filtered using at least one of a dechirping filter and a low pass filter.

6. A radar signal processing method comprising:
receiving a radar signal reflected from an object;
extracting an imaginary part of the radar signal through a conversion of a quadrature-phase (Q) channel of the radar signal;
extracting an error due to an in-phase/quadrature-phase (I/Q) imbalance in the radar signal;
outputting a correction signal obtained by compensating for the I/Q imbalance in the radar signal, wherein the correction signal includes a Q channel based on multiplying a complex conjugate of the error, and the imaginary part; and
detecting the object from which the radar signal is reflected based on the correction signal.

7. The method of claim 6 , wherein the outputting comprises:
extracting a real part of the radar signal through a conversion of an in-phase (I) channel of the radar signal in response to the I/Q imbalance occurring in the radar signal, wherein the real part includes an I channel and a Q channel;
extracting the error due to the I/Q imbalance based on the real part and the imaginary part, wherein the error includes an I channel and a Q channel; and
generating the correction signal obtained by compensating for the I/Q imbalance in the radar signal based on the error.

8. The method of claim 7 , wherein the extracting of the real part comprises:
performing a discrete Fourier transform (DFT) on the I channel signal;
determining a spectrum of the I channel signal based on a DFT result of the I channel signal; and
extracting the real part based on an inverse DFT result of the spectrum of the I channel signal.

9. The method of claim 7 , wherein the extracting of the imaginary part comprises:
performing a DFT on the Q channel signal;
determining a spectrum of the Q channel signal based on a DFT result of the Q channel signal; and
extracting the imaginary part based on an inverse DFT result of the spectrum of the Q channel signal.

10. The method of claim 6 , wherein the outputting comprises:
outputting a Q channel of the correction signal based on the error and the imaginary part; and
outputting an I channel of the correction signal based on the in-phase (I) channel signal of the radar signal.

11. The method of claim 6 , wherein the detecting comprises:
defining an auto-correlation matrix based on the correction signal;
extracting a signal eigenvector matrix by applying an eigenvalue decomposition (EVD) to the auto-correlation matrix;
defining a signal sub-matrix based on the signal eigenvector matrix;
estimating a delay path of the radar signal based on the signal sub-matrix; and
detecting the object from which the radar signal is reflected based on the delay path.

12. A radar signal processing apparatus comprising:
a real part extractor configured to extract a real part of a radar signal in which an in-phase/quadrature-phase (I/Q) imbalance occurs through a conversion of an in-phase (I) channel signal of the radar signal, wherein the real part includes an I channel and a Q channel;
an imaginary part extractor configured to extract an imaginary part of the radar signal through a conversion of a quadrature-phase (Q) channel signal of the radar signal, wherein the imaginary part includes an I channel and a Q channel;
an error extractor configured to extract an error due to the I/Q imbalance based on multiplying a complex conjugate of the I channel and the Q channel of the real part, and the I channel and the Q channel of the imaginary part; and
a correction signal outputter configured to output a correction signal obtained by compensating for the I/Q imbalance of the radar signal based on the error.

13. The apparatus of claim 12 , wherein the real time extractor is configured to perform a discrete Fourier transform (DFT) on the I channel signal, determine a spectrum of the I channel signal based on a DFT result of the I channel signal, and extract the real part based on an inverse DFT result of the spectrum of the I channel signal.

14. The apparatus of claim 12 , wherein the imaginary part extractor is configured to perform a DFT on the Q channel signal, determine a spectrum of the Q channel signal based on a DFT result of the Q channel signal, and extract the imaginary part based on an inverse DFT result of the spectrum of the Q channel signal.

15. The apparatus of claim 12 , wherein the correction signal outputter is configured to output a Q channel of the correction signal based on the error and the imaginary part and output an I channel of the correction signal based on the real part.

16. The apparatus of claim 12 , wherein the radar signal is a signal generated based on a radar signal reflected from an object and filtered using at least one of a dechirping filter and a low pass filter.

17. The method of claim 1 , wherein the conversion of the in-phase (I) channel signal of the radar signal is based on a Hilbert transform, and wherein the conversion of the quadrature-phase (Q) channel signal of the radar signal is based on another Hilbert transform.

18. The method of claim 6 , wherein the conversion of the quadrature-phase (Q) channel signal of the radar signal is based on a Hilbert transform.

19. The apparatus of claim 12 , wherein the real part extractor is further configured to use a Hilbert transform for the conversion of the in-phase (I) channel signal of the radar signal; and wherein the imaginary part extractor is further configured to use another Hilbert transform for the conversion of the quadrature-phase (Q) channel signal of the radar signal.

Assignees

• Daegu Gyeongbuk Inst Science & Tech

Inventors

• Kim Sang Dong
• Oh Dae Gun
• Lee Jong Hun

Classifications

• G01S2007/358

  Physics · mapped topic

• G01S13/34

  using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal · CPC title

• G01S7/352 Primary

  Receivers · CPC title

• G01S7/4021

  of receivers · CPC title

• H04L27/38

  Demodulator circuits; Receiver circuits · CPC title