KR101330530B1 - Hybrid radar using rf-optical signal, and method for detecting distance using the hybrid radar - Google Patents

Abstract

The present invention relates to a hybrid radar using an RF-light signal and a distance detection method using the same. The hybrid radar using the RF-light signal according to an embodiment of the present invention generates a target signal by generating an RF transmission signal that is a frequency modulated signal. An RF signal processing unit for transmitting to the target and receiving the reflected RF reception signal, an optical signal processing unit for generating and transmitting the optical transmission signal optically modulated with the RF transmission signal to the target, and receiving the reflected light reception signal; And a distance estimator configured to estimate a distance from the target using the RF received signal and the light received signal.
Accordingly, the distance to the target can be detected more accurately using the signal reflected by transmitting the RF signal to the target and the signal reflected by transmitting the optical signal.

Description

Hybrid radar using RF-optical signal and distance detection method using same {HYBRID RADAR USING RF-OPTICAL SIGNAL, AND METHOD FOR DETECTING DISTANCE USING THE HYBRID RADAR}

The present invention relates to a hybrid radar using an RF-optical signal and a distance detection method using the same, and more particularly, a technique for detecting a distance from the target by analyzing an reflected signal by transmitting an RF signal and an optical signal to the target. Is initiated.

Today, the application of radar-based driver safety systems continues to expand. In particular, Adaptive Cruise Control (ACC) systems are already commercially available on the market using 24 GHz and 77 GHz radar. In such driver safety systems, even in the presence of multiple targets, the distance and speed of each target must be able to be measured simultaneously with high accuracy.

Detection radar has a limitation in detection resolution depending on the bandwidth and signal processing method of the frequency used. In order to improve the limited resolution of the detection radar, it is necessary to extend the bandwidth to ultra-wideband. Ultra Wide Band (UWB) is a system that occupies more than 25% of the center frequency bandwidth or 1.5GHz or more bandwidth to distinguish it from the existing narrowband system and broadband system described by 3G cellular technology. Defined as wireless transmission technology.

The UWB system has a relatively low spectral power density over a much wider frequency band than a conventional narrowband system or a wideband CDMA system, so that the frequency can be shared without interfering with the existing wireless communication system. However, in the case of the detection radar, since the operating frequency uses a frequency band of up to 100 GHz or more, expensive ultra-wideband components are required to increase the price of the radar system.

The background technology of the present invention is described in Republic of Korea Patent Publication No. 10-1092567 (2011. 12. 05).

An object of the present invention is to accurately detect a distance from a target using a signal reflected by transmitting an RF signal to the target and a signal reflected by transmitting an optical signal.

A hybrid radar using an RF-optical signal according to an embodiment of the present invention, an RF signal processor for generating and transmitting an RF transmission signal, which is a frequency modulated signal, to a target and receiving a reflected RF reception signal, and the RF transmission signal An optical signal processor for generating an optically modulated optical transmission signal, transmitting the optical transmission signal to the target, and receiving the reflected optical reception signal, and estimating a distance from the target using the RF reception signal and the optical reception signal Contains wealth.

The RF signal processor may separate the RF transmission signal into a first split signal and a second split signal through a directional coupler, transmit the first split signal to the optical signal processor, and amplify the second split signal. To the target.

The RF signal processor may generate a baseband signal using an oscillation signal having a predetermined frequency and the RF reception signal, or may generate a bit signal using the RF transmission signal and the RF reception signal.

The optical signal processor may detect a phase component of the optical reception signal.

The distance estimator may include a first distance estimator configured to analyze a spectrum of the generated baseband signal or a bit signal or measure a time delay to estimate a distance range from the target, and a phase component of the optical reception signal. And a second distance estimator configured to spectrally analyze and estimate the distance to the target within the estimated distance range.

In a distance detection method using a hybrid radar using an RF-optical signal according to another embodiment of the present invention, an RF transmission signal which is a frequency modulation signal and an optical transmission signal obtained by optically modulating the RF transmission signal are generated and transmitted to a target. And receiving an RF reception signal and an optical reception signal reflected from the target, and estimating a distance to the target using the RF reception signal and the optical reception signal.

As described above, according to the embodiment of the present invention, the distance from the target can be detected more accurately by using the reflected signal by transmitting the RF signal to the target and the reflected signal by transmitting the optical signal. In addition, the resolution of the radar can be increased without using ultra-wideband components, and the cost of building the radar can be reduced.

1 is a block diagram of a hybrid radar using an RF-light signal according to an embodiment of the present invention,
2 is a configuration diagram showing in more detail the configuration of a hybrid radar using the RF-light signal according to FIG.
3 is a flowchart of a distance detection method using a hybrid radar using an RF-light signal according to FIG. 1;
FIG. 4 is an exemplary diagram for describing setting a range cell in a distance estimator of a hybrid radar using an RF-light signal according to FIG. 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms used are terms selected in consideration of the functions in the embodiments, and the meaning of the terms may vary depending on the user, the intention or the precedent of the operator, and the like. Therefore, the meaning of the terms used in the following embodiments is defined according to the definition when specifically defined in this specification, and unless otherwise defined, it should be interpreted in a sense generally recognized by those skilled in the art.

1 is a configuration diagram of a hybrid radar using an RF-light signal according to an embodiment of the present invention, Figure 2 is a configuration diagram showing the configuration of a hybrid radar using an RF-light signal according to Figure 1 in more detail.

1 and 2, a hybrid radar 100 using an RF-light signal according to an embodiment of the present invention may include an RF signal processor 110, an optical signal processor 120, and a distance estimator 130. Include.

The RF signal processor 110 generates and transmits a radio frequency (RF) transmission signal, which is a frequency modulation signal, to a target, and receives an RF reception signal reflected from the target. Here, the target refers to an object that receives the radar signal and reflects it, and includes a stationary object such as a building structure or a moving object such as a vehicle. In this case, the RF transmission signal or the RF reception signal may be a signal of a frequency modulation continuous wave (FMCW) scheme.

In addition, the RF signal processor 110 divides the RF transmission signal modulated by a frequency modulation or pulse modulation method into a first separation signal and a second separation signal, and transmits the first separation signal to the optical signal processing unit 120. The second split signal is amplified and transmitted to the target. In addition, the RF signal processor 110 may generate a baseband signal by combining the RF received signal with an oscillation signal having a predetermined frequency, or may generate a beat signal using the RF transmission signal and the RF received signal. have.

For example, the RF signal processor 110 may include a waveform generator 111, a frequency synthesizer 112, an oscillator 113, a directional coupler 114, a power amplifier 115, and a low noise amplifier 116. ), But is not necessarily limited thereto.

The waveform generator 111 generates a waveform signal having frequency modulation information according to a user setting. The oscillator 112 generates an oscillation signal having a preset frequency in response to the waveform signal. The frequency synthesizer 113 generates a synthesized signal using the waveform signal generated by the waveform generator 111 and the oscillation signal generated by the oscillator 112. The directional coupler 114 (DC: Directional Coupler) separates the synthesized signal, and transmits the first split signal to the optical modulator 121 of the optical signal processor 120, and the second split signal is output to the power amplifier 115. do. The power amplifier 115 transmits the RF transmission signal generated by amplifying the second separated signal to the target through an antenna.

In addition, the low noise amplifier 116 (LNA: Low Noise Amplifier) of the RF signal processing unit 110 amplifies only the signal from which the noise included in the RF received signal received through the antenna is output to the frequency synthesizer 112. In this case, the frequency synthesizer 112 generates a baseband signal by synthesizing the oscillator signal of the oscillator 113 and the noise-received RF received signal or generating a beat signal using the RF transmitted signal and the RF received signal. Can be generated. The frequency synthesizer 112 outputs the generated baseband signal or bit signal to the distance estimator 130.

On the other hand, the optical signal processing unit 120 transmits the optical transmission signal obtained by optically modulating the RF transmission signal to the target, and receives the light reception signal reflected therefrom. In addition, the optical signal processor 120 detects a phase component of the optical reception signal.

For example, the optical signal processor 120 may include an optical modulator 121, a laser 122, a photo detector 123, and a phase detector 124 as shown in FIG. 2, but the present disclosure is not limited thereto. It is not.

The optical modulator 121 receives the second separation signal received from the directional coupler 114 of the RF signal processing unit 110 and modulates the RF transmission signal by adjusting the intensity of light, which is a carrier wave, and then lasers 122 ) The laser 122 transmits the light modulated light transmission signal to the target. The photo detector 123 detects the light reception signal received by reflecting the light transmission signal transmitted to the target, and outputs the detected light reception signal to the phase detector 124. Phase detector 124 detects phase components with respect to the light received signal. In this case, it is possible to detect the phase component of the optical reception signal by receiving the modulation condition applied when generating the optical transmission signal from the optical modulator 121.

Meanwhile, the distance estimator 130 estimates the distance to the target using the RF received signal and the light received signal. In more detail, the distance estimator 130 includes a first distance estimator 131 and a second distance estimator 132. Here, the first distance estimator 131 estimates the distance to the target based on the RF received signal, and the second distance estimator 132 estimates the distance to the target based on the light received signal. Accordingly, the distance range between the target and the hybrid antenna may be primarily determined by the first distance estimator 131, and the distance may be secondarily estimated by the second distance estimator 132.

In addition, the first distance estimator 131 may estimate the distance to the target from the baseband signal or the bit signal generated using the RF received signal through spectrum analysis or measure the time delay to estimate the distance to the target. have. For example, the first distance estimator 131 may include, but is not necessarily limited to, a low pass filter 133, an A / D converter 135, and a digital signal processor 137 as shown in FIG. 2.

The low pass filter 133 (LPF: Low Pass Filter) blocks a high band signal of a predetermined band among the frequency synthesized signals of the RF received signal output from the frequency synthesizer 112 of the RF signal processor 110, The signal in the band is passed to remove noise of high frequency components. The A / D converter 135 converts the analog signal output from the low pass filter 133 into a digital signal. The digital signal processor 137 uses a fast Fourier transform (FFT) to estimate the distance from the target through spectrum analysis on the signal converted by the A / D converter 135 or to estimate the distance from the target by measuring a time delay. Perform Fourier Transformation. In addition, the digital signal processor 136 may generate and transmit a control signal for generating a waveform to the waveform generator 111 of the RF signal processor 110.

Meanwhile, the second distance estimator 132 spectra analyzes the phase component of the light reception signal and secondly estimate the distance to the target within the distance range estimated by the first distance estimator 131. For example, the second distance estimator 132 may include the distortion processor 134 and the digital signal processor 136 as shown in FIG. 2, but is not limited thereto.

The distortion processor 134 removes noise from satellite components of the light reception signal detected by the phase detector 124 of the optical signal processing unit 120. The digital signal processor 136 estimates the distance from the distortion processor 134 to the target through spectra analysis or estimates the distance from the target by measuring a time delay to perform a Fast Fourier Transform (FFT). ). In addition, the digital signal processor 137 may generate and transmit a control signal for generating a waveform to the waveform generator 111 of the RF signal processor 110. In this case, the digital signal processor 137 included in the first distance estimator 131 and the digital signal processor 136 included in the second distance estimator 132 may be implemented as one signal processor.

3 is a flowchart of a distance detection method using a hybrid radar using an RF-light signal according to FIG. 1.

Referring to FIG. 3, in the distance detecting method using the hybrid radar 100 using the RF-optical signal according to another embodiment of the present invention, the RF signal processing unit 110 and the optical signal processing unit 120 first transmit an RF signal. A signal and an optical transmission signal obtained by optically modulating the RF transmission signal are generated and transmitted to the target (S310). In this case, the RF transmission signal is a pulse modulated or frequency modulated signal. In addition, the RF transmission signal and the optical transmission signal may be transmitted simultaneously or with a time difference.

Next, the RF signal processing unit 110 and the optical signal processing unit 120 receives the RF reception signal and the light reception signal reflected from the target (S320). The RF signal processor 110 may generate a beat signal representing a difference from the RF transmission signal or generate a baseband signal using the RF received signal. In addition, the optical signal processor 120 may receive the optical reception signal and detect a phase component of the optical reception signal.

Next, the distance estimator 130 estimates the distance to the target using the RF received signal and the light received signal (S330). In this case, the distance range from the target may be estimated primarily through spectrum analysis or time delay measurement with respect to the RF received signal, and the distance from the target may be estimated secondarily through spectrum analysis with respect to the optical received signal. have. The distance to the second estimated target is estimated within a range of distance to the first estimated target, and more accurate distance estimation for the target is possible.

FIG. 4 is an exemplary diagram for describing setting a range cell in a distance estimator of a hybrid radar using an RF-light signal according to FIG. 1.

Referring to FIG. 4, a range cell represents a cell in which radar signals reflected and received from a target are collected by being divided into a plurality of cell sections. The distance to the target may be estimated by performing fast Fourier transform (FFT) on each range cell to perform data processing. In the hybrid radar 100 using the RF-light signal according to the embodiment of the present invention, the distance estimator 130 configures an upper distance range cell by using an RF received signal, and uses an optical received signal to form an upper distance range cell. Each lower distance range cell can be configured.

Accordingly, the distance range with the target is estimated by data processing the upper distance range cell primarily through the RF reception signal, and the distance with the target is estimated by data processing the lower distance range cell secondarily through the optical reception signal. By doing so, the distance to the target can be estimated more accurately.

As described above, according to the exemplary embodiment of the present invention, the distance from the target can be detected more accurately by using the reflected signal by transmitting the RF signal to the target and the reflected signal by transmitting the optical signal. In addition, the resolution of the radar can be increased without using ultra-wideband components, and the cost of building the radar can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, Therefore, the present invention should be construed as a description of the claims which are intended to cover obvious variations that can be derived from the described embodiments.

100: hybrid radar
110: RF signal processing unit
111: waveform generator
112: oscillator
113: frequency synthesizer
114: directional coupler
115: power amplifier
116: low noise amplifier
120: optical signal processing unit
121: light modulator
122: laser
123; Photo detector
124: phase detector
130: distance estimation unit
131: first distance estimation unit
132: second distance estimation unit
133: low pass filter
134: distortion handler
135: A / D Converter
136, 137: digital signal processor

Claims (10)

An RF signal processor for generating and transmitting an RF transmission signal, which is a frequency modulation signal, to a target and receiving a reflected RF reception signal;
An optical signal processor for generating an optical transmission signal obtained by optically modulating the RF transmission signal, transmitting the optical transmission signal to the target, and receiving the reflected optical reception signal; And
A distance estimator configured to estimate a distance from the target using the RF received signal and the optical received signal,
The RF signal processing unit,
RF- to separate the RF transmission signal into a first separation signal and a second separation signal through a directional coupler, transmit the first separation signal to the optical signal processor, amplify a second separation signal and transmit the RF- Hybrid radar using light signal. delete The method of claim 1,
The RF signal processing unit,
And a baseband signal using the oscillation signal having a predetermined frequency with the RF reception signal or a bit signal using the RF transmission signal and the RF reception signal. The method of claim 1,
The optical signal processing unit,
And a hybrid radar using an RF-light signal to detect a phase component of the light reception signal. The method of claim 3,
The distance estimator,
A first distance estimator configured to analyze a spectrum of the generated baseband signal or a bit signal or measure a time delay to estimate a distance range from the target; And
And a second distance estimator configured to spectrally analyze a phase component of the light reception signal and secondly estimate a distance to the target within the estimated distance range. In the distance detection method using a hybrid radar,
Generating and transmitting an RF transmission signal, which is a frequency modulation signal, and an optical transmission signal obtained by optically modulating the RF transmission signal, to a target;
Receiving an RF received signal and an optical received signal reflected from the target; And
Estimating a distance to the target using the RF received signal and the optical received signal,
Generating and transmitting the RF transmission signal which is the frequency modulated signal and the optical transmission signal obtained by optically modulating the RF transmission signal to a target,
RF that separates the RF transmission signal into a first separation signal and a second separation signal through a directional coupler, optically modulates the first separation signal, and transmits the first separation signal to the target, and amplifies the second separation signal and transmits the second separation signal to the target. -Distance detection method using a hybrid radar using an optical signal. delete The method according to claim 6,
Receiving the RF received signal and the light received signal reflected from the target,
Distance using a hybrid radar using an RF-optical signal generating a baseband signal using the oscillation signal having a predetermined frequency and the RF reception signal or a bit signal using the RF transmission signal and the RF reception signal Detection method. The method according to claim 6,
Receiving the RF received signal and the light received signal reflected from the target,
A distance detection method using a hybrid radar using an RF-light signal for detecting a phase component of the light reception signal. 9. The method of claim 8,
Estimate the distance to the target using the RF received signal and the light received signal,
Estimating a range of distance from the target by analyzing a spectrum of the generated baseband signal or a bit signal or measuring a time delay; And
Spectrally analyzing the phase component of the optical reception signal to estimate the distance to the target within the estimated distance range using a hybrid radar using an RF-light signal.

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