Method and apparatus for detecting target using radar

Patent metadata

Field	Value
Publication number	US-9971028-B2
Application number	US-201514608406-A
Country	US
Kind code	B2
Filing date	Jan 29, 2015
Priority date	Feb 11, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Provided is a method and apparatus for detecting a target using radar, the apparatus including a transmitter to generate a frequency modulated continuous waveform (FMCW) of a baseband, convert the FMCW into a signal of a predetermined frequency band, and emit the signal to a target through radar, a receiver to receive the signal reflected from the target through each antenna of a multi-array antenna, and estimate information on the target based on the signal received through each antenna, and a processor to control operations of the transmitter and the receiver.

First claim

What is claimed is:

1. A target detection apparatus comprising:
a transmitter to generate a frequency modulated continuous waveform (FMCW) of a baseband, to convert the FMCW into a signal of a predetermined frequency band, and to emit the converted signal to a target through radar;
a receiver to receive the signal reflected from the target through each antenna of a multi-array antenna, and to estimate information on the target based on the signal received through respective one of the multi-array antenna; and
a processor to control operations of the transmitter and the receiver, the control operations being performed by calculating, by the processor, a start point of a valid radar reception signal transmitted from each antenna of a multi-array antenna, the start point being calculated based on an output valid signal provided from the transmitter as a synchronization signal, wherein
the processor is configured to receive a number of a chirps to be transmitted by the transmitter and to receive an interrupt signal indicating a start point of each chirp section of the FMCW from the receiver and to provide a control signal allowing the transmitter to generate the FMCW of a corresponding section.

2. The apparatus of claim 1 , wherein the transmitter comprises:
an FMCW generator to generate the FMCW of the baseband; and
a radio frequency (RF) transmitter to convert the FMCW into the signal of the predetermined frequency band, and to emit the signal through the radar.

3. The apparatus of claim 2 , wherein the FMCW generator generates the FMCW of the corresponding section under a control of the processor and transfers an output valid signal indicating that the FMCW of the corresponding section is being outputting, to the radar signal processor.

4. The apparatus of claim 1 , wherein the radar signal processor informs the processor of the start point of each chirp section in the FMCW as an interrupt, and informs the FMCW generator of a number of the chirps to be transmitted by the transmitter.

5. The apparatus of claim 1 , wherein all or part of functions of the radar signal processor is processed by the processor through software.

6. The apparatus of claim 1 , wherein a first waveform for detecting a short range target and a second waveform for detecting a long range target occur sequentially during one cycle in the FMCW.

7. The apparatus of claim 6 , wherein the first waveform comprises five chirps, each of the five chirps having a different time-based frequency change inclination.

8. The apparatus of claim 6 , wherein the second waveform comprises seven chirps, each of the seven chirps having a different time-based frequency change inclination.

9. The apparatus of claim 1 , wherein the receiver calculates a beat frequency for each segment based on the signal received through each antenna, and estimates information comprising at least one of a range, a velocity, and an azimuth of the target.

10. The apparatus of claim 1 , wherein the receiver comprises:
a multi-array antenna comprising a plurality of antennas receiving signals reflected from the target;
RF receivers to convert the signals received through the antennas of the multi-array antenna, into complex signals of the baseband;
analog-to-digital converters (ADCs) to convert the complex signals into digital signals; and
a radar signal processor to process the digital signals and estimate information on the target.

11. The apparatus of claim 10 , wherein each of the RF receivers multiplies the signal of the predetermined frequency band provided by the transmitter, by the signals received by the respective antennas, and converts results of the multiplying into the complex signals of the baseband.

12. The apparatus of claim 10 , wherein a number of ADCs is disposed proportional to a number of antennas included in the multi-array antenna.

13. The apparatus of claim 10 , wherein the radar signal processor comprises:
an ADC symbol formatter to segment serial bits input from the ADCs based on a unit of an ADC symbol, and to output the ADC symbol through a rearrangement based on an arrangement order of the antennas;
a direct current (DC) offset remover to remove a DC component from the rearranged ADC symbol;
a first window to apply a window function to degrade a side-lobe level of an interference signal with respect to the ADC symbol from which the DC component is removed;
a digital beam former (DBF) to combine the signals received through the antennas to be signals received in a predetermined direction through a digital operation based on an output signal of the first window, and output the combined signals for each beam;
a second window to apply a window function to reduce a leakage error occurring during a fast Fourier transform (FFT) performed on the combined signals;
a fast Fourier transformer to perform the FFT on an output signal of the second window;

a constant false alarm rate (CFAR) detector to select predetermined beat frequencies by applying a variable detection threshold to an output signal of the FFT;
an estimator to estimate information comprising a range, a velocity, and an azimuth of the target from the selected beat frequencies; and
a chirp counter to calculate a chirp number and a start point of each chirp section in the FMCW.

14. The apparatus of claim 13 , wherein the DBF multiplies the output signal through each antenna of the first window by a preset weighted value and combines a signal received in a predetermined direction through a phase rotation.

15. A receiver in a target detection apparatus, the receiver comprising:
a multi-array antenna comprising a plurality of antennas receiving signals reflected from a target;
radio frequency (RF) receivers to convert the signals received through the antennas of the multi-array antenna, into complex signals of a baseband;
analog-to-digital converters (ADCs) to convert the complex signals of the baseband into digital signals; and
a radar signal processor to calculate predetermined beat frequencies based on the digital signals, to calculate a start point of a valid radar reception signal transmitted from each antenna of a multi-array antenna, the start point being calculated based on an output valid signal provided from a transmitter as a synchronization signal, and to estimate information of a target based on the calculated beat frequencies, and the radar signal processor to receive a number of a chirps to be transmitted by the transmitter, to receive an interrupt signal indicating a start point of each chirp section of the FMCW from the receivers and to provide a control signal allowing the transmitter to generate the FMCW of a corresponding section,
the beat frequencies being calculated by
converting the signal received through each antenna of the multi-array antenna, into complex signals of the baseband,
converting the complex signals of the baseband into digital signals, and
selecting the predetermined beat frequencies.

16. A target detection method comprising:
generating an interrupt requesting for a generation of a frequency modulated continuous waveform (FMCW);
setting values for use in the generation of the FMCW in an FMCW generator;
generating an FMCW of a baseband;
converting the FMCW into a signal of a predetermined frequency band and emitting the signal to a target through radar;
receiving the signal reflected from the target, through each antenna of a multi-array antenna during a valid output section of a transmitter;
calculating predetermined beat frequencies based on the signal received through each antenna and calculating a start point

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Park Ki Hyuk

Classifications

• G01S13/931

  of land vehicles · CPC title

• G01S7/354

  Extracting wanted echo-signals (Doppler systems G01S13/50) · CPC title

• G01S2007/358

  Physics · mapped topic

• G01S13/345

  using triangular modulation · CPC title

• G01S13/584 Primary

  adapted for simultaneous range and velocity measurements · CPC title