KR102426706B1 - Synthetic aperture radar and compensation method for synthetic aperture radar chirp signal - Google Patents

Abstract

The image radar includes an image radar controller that generates a chirp sample before performing an operation mode, and a chirp signal generator that converts the chirp sample during operation mode to generate a chirp signal, wherein the image radar controller includes an error envelope in the frequency domain A memory storing an error envelope sample table including a sample and an error envelope sample in the time domain, a chirp parameter transmitted from a ground station command generator to perform the operation mode, and a predistortion phase compensation sample using the error envelope sample table and A predistortion compensation sample unit for generating a predistortion magnitude compensation sample, and a chirp sample calculation unit for calculating a chirp sample in which a phase error and a magnitude error are compensated by using the predistortion phase compensation sample and the predistortion magnitude compensation sample .

Description

SYNTHETIC APERTURE RADAR AND COMPENSATION METHOD FOR SYNTHETIC APERTURE RADAR CHIRP SIGNAL

The present invention relates to an imaging radar and a method for compensating a chirp signal of an imaging radar, and more particularly, to an imaging radar and a method for compensating a chirp signal of an imaging radar capable of compensating for a frequency domain error and a time domain error.

The image radar is a device that can acquire ground images in all weather day and night based on radar signals. Imaging radar uses a linear frequency modulated signal called a chirp to transmit and receive signals. The size and phase of the chirp signal may be distorted due to the characteristics of transmission lines and components included in the image radar transmission/reception path, and such distortion has a great effect on the image radar performance. In general, the greater the bandwidth and pulse width of the chirp signal, the greater the distortion. As the resolution requirement performance of the image radar increases, the bandwidth of the required signal is increasing. , the distortion of the chirp signal has a greater effect on the degradation of image radar performance.

A method commonly applied to reduce distortion of a chirp signal is a pre-distortion technique. Predistortion is a method of alleviating signal distortion in an image radar by applying distortion to be generated on a transmission/reception path in the reverse direction in advance when generating a signal.

The prior art uses a frequency domain compensation scheme for predistortion. That is, it is a method of deriving an error on the transmission/reception path of the imaging radar equipment as the magnitude and phase error of the frequency domain, and compensates in advance at the time of signal generation. This frequency domain compensation method is made on the assumption that the error on the transmission/reception path of the image radar only changes according to the frequency of the signal and does not change with time. However, a nonlinear element such as an amplifier included in a transmission/reception path has a characteristic in which a frequency response changes according to time (pulse length). For example, a 50us pulse width signal having a 100MHz bandwidth and a 100us pulse width signal having the same bandwidth may have different frequency response characteristics while passing through an image radar. This means that frequency domain compensation alone may not be sufficient to compensate for equipment errors.

In addition, the prior art uses a Taylor series modeling technique to model the magnitude and phase of the error. That is, if the signal error caused by the image radar equipment is modeled as a Taylor series in advance on the ground, and the coefficient of the Taylor series is increased on the ground through a macro-command when performing the operation mode, the coefficient in the image radar is is used to calculate the predistortion value to be applied to all signal samples for each sample. However, this method has a problem in that the amount of computation for calculating the predistortion value for each sample increases exponentially as the order of the Taylor series increases. In general, a second or third order Taylor series modeling method is applied to an image radar, and accordingly, accurate modeling of equipment errors becomes difficult and accurate compensation for errors becomes impossible.

An object of the present invention is to provide an image radar capable of compensating for a frequency domain error and a time domain error and a method for compensating a chirp signal of an image radar.

An image radar according to an embodiment of the present invention includes an image radar controller for generating a chirp sample before performing an operation mode, and a chirp signal generator for generating a chirp signal by converting the chirp sample while performing an operation mode, the image radar The controller includes a memory storing an error envelope sample table including an error envelope sample in a frequency domain and an error envelope sample in a time domain, a chirp parameter transmitted from a ground station command generator for performing the operation mode, and the error envelope sample table A predistortion compensation sample unit for generating a predistortion phase compensation sample and a predistortion magnitude compensation sample using and a book sample calculation unit for calculating.

로 최적 첩 위상 샘플을 산출하고, 상기 최적 첩 위상 샘플에 상기 전치왜곡 위상 보상 샘플을 더하여 위상 오차가 보상된 첩 샘플을 산출하고, 상기

는 최적 첩 위상 샘플이고, 상기

는 첩 기울기이고, 상기

는 시작 주파수이고, 상기

은 시작 위상이고, 상기

는 샘플의 길이 또는 펄스폭일 수 있다.The image radar controller is

calculating an optimal chir phase sample with , and adding the predistortion phase compensation sample to the optimal chir phase sample to calculate a chirp sample for which a phase error is compensated, and

is the optimal chirp phase sample, and

is the chirp slope, and

is the starting frequency, and

is the starting phase, and

may be the length of the sample or the pulse width.

An image radar according to another embodiment of the present invention includes a chirp signal generator for generating a chirp signal based on information received while performing an operation mode, and an error envelope sample including an error envelope sample in a frequency domain and an error envelope sample in a time domain an image radar controller including a memory storing a table, and transmitting a chirp parameter and an error envelope sample in the frequency domain and an error envelope sample in the time domain to the chirp signal generator before performing an operation mode, the chirp signal generator is, a predistortion compensation sample unit for generating a predistortion phase compensation sample and a predistortion magnitude compensation sample using the chirp parameter, the error envelope sample in the frequency domain, and the error envelope sample in the time domain, and the chirp parameter, the and a chir signal generator configured to generate the chirp signal by using the predistortion phase compensation sample and the predistortion magnitude compensation sample.

The predistortion compensation sample unit includes: a first upsampling unit for upsampling the error envelope sample of the frequency domain at a first upsampling ratio; a first low pass filter for interpolating the upsampled error envelope sample of the frequency domain; A second upsampling unit for upsampling the time domain error envelope sample at a second upsampling ratio, a second low pass filter for interpolating the upsampled time domain error envelope sample, and the interpolated frequency domain error envelope and an adder configured to generate the predistortion phase compensation sample and the predistortion magnitude compensation sample by adding a sample and an error envelope sample of the interpolated time domain.

The predistortion compensation sample unit includes a first sample number adjusting unit that adjusts the error envelope samples of the interpolated frequency domain according to the number of transmission samples and transmits them to the adder, and transmits the interpolated time domain error envelope samples to the number of transmission samples. The method may further include a second number of samples adjusting unit that adjusts to fit and transmits it to the adder.

The chir signal generator includes an optimal chir phase sample generator configured to generate an optimal chir phase sample corresponding to the chir parameter, and an adder configured to generate a phase error-compensated chirp sample by adding the optimal chir phase sample and the predistortion phase compensation sample , a phase-magnitude converter for phase-magnitude-converting the phase-error-compensated chirp sample, a multiplier for multiplying the phase-magnitude-transformed chirp sample by the predistortion magnitude compensation sample to generate a magnitude-error-compensated chirp sample, and the A digital-to-analog converter for generating the chirp signal by converting the magnitude error-compensated chirp sample into an analog signal.

The method for compensating for a chirp signal of an image radar according to another embodiment of the present invention includes generating a predistortion phase compensation sample using the chirp parameter and an error envelope sample table stored in a memory when a chirp parameter is received, the chirp generating a predistortion magnitude compensation sample by using the parameter and the error envelope sample table; generating an optimal chir phase sample corresponding to the chir parameter; adding the predistortion phase compensation sample to the optimal chir phase sample Calculating an error-compensated chirp sample, phase-magnitude transforming the phase-error-compensated chirp sample, and multiplying the phase-magnitude-transformed chirp sample by the predistortion magnitude compensation sample to calculate a magnitude error-compensated chirp sample and converting the magnitude error-compensated chirp sample into an analog signal to generate a chirp signal.

The error envelope sample table may include an error envelope sample in a frequency domain and an error envelope sample in a time domain.

The generating of the predistortion phase compensation sample includes upsampling the phase error envelope sample of the frequency domain by a first upsampling ratio, interpolating the upsampled phase error envelope sample of the frequency domain, the time upsampling a phase error envelope sample of the domain to a second upsampling ratio, interpolating the upsampled time domain phase error envelope sample, and the interpolated frequency domain phase error envelope sample with the interpolated time and generating the predistortion phase compensation sample by adding the phase error envelope samples of the region.

The generating of the predistortion magnitude compensation sample includes upsampling the magnitude error envelope sample of the frequency domain by a first upsampling ratio, interpolating the magnitude error envelope sample of the upsampled frequency domain, the time upsampling a size error envelope sample of a region by a second upsampling ratio, interpolating the size error envelope sample of the upsampled time domain, and the interpolated frequency domain amplitude error envelope sample and the interpolated time and generating the predistortion phase compensation sample by adding the size error envelope sample of the region.

More accurate error compensation is possible by classifying the signal error induced by the imaging radar equipment into a frequency domain error and a time domain error, and applying the envelope sampling technique as the error modeling method and the interpolation filter technique as the predistortion application method. This can improve the signal quality of the imaging radar and ensure better performance. In particular, in the case of a wideband, signal distortion is generally severe, but the performance of an image radar based on a wideband signal can be improved by using the proposed technology.

1 is a block diagram illustrating an image radar compensating for magnitude and phase errors of a chirp signal in a memory-map method according to an embodiment of the present invention.
2 is a flowchart illustrating a method of compensating for magnitude and phase errors of a chirp signal in a memory-map method according to an embodiment of the present invention.
3 is a block diagram illustrating an image radar for compensating for magnitude and phase errors of a chirp signal by a direct digital synthesis method according to an embodiment of the present invention.
4 is a block diagram illustrating a predistortion compensation sample unit according to an embodiment of the present invention.
5 is an exemplary diagram illustrating an example of a process of generating a predistortion compensation sample.
6 is a block diagram illustrating a chirp signal generator according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

In addition, throughout the specification, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, an image radar compensating for a chirp signal in a memory-map method and a chirp signal compensation method will be described with reference to FIGS. 1 and 2 .

1 is a block diagram illustrating an image radar compensating for magnitude and phase errors of a chirp signal in a memory-map method according to an embodiment of the present invention.

Referring to FIG. 1 , the image radar 200 includes an image radar controller 210 and a chirp signal generator 220 . In the memory-map method, the image radar controller 210 generates a chirp sample based on software before performing the operation mode for acquiring the image and transmits it to the chirp signal generator 220, and the chirp signal generator 220 performs the operation mode During digital-analog conversion of the chirp sample, a chirp signal is generated.

The image radar controller 210 includes a memory 10 , a predistortion compensation sampler 20 and a chirp sample calculator 30 , and the chirp signal generator 220 uses a digital-to-analog converter (DAC) 40 . include In the memory-map method, the predistortion compensation sample unit 20 and the chirp sample calculation unit 30 of the image radar controller 210 are implemented in software. In particular, the predistortion compensation sampler 20 implements the predistortion compensation sampler 20 in software in a direct digital synthesis (DDS) method, which will be described later with reference to FIG. 4 .

The memory 10 stores an error envelope sample table. The error envelope sample table includes an error envelope sample in the frequency domain and an error envelope sample in the time domain. The frequency domain error envelope sample may include a frequency domain phase error envelope sample and a frequency domain magnitude error envelope sample. The time domain error envelope sample may include a time domain phase error envelope sample and a time domain magnitude error envelope sample.

The predistortion compensation sample unit 20 generates a predistortion compensation sample using the chirp parameter and the error envelope sample table stored in the memory 10 . The predistortion compensation sample may include a predistortion phase compensation sample and a predistortion magnitude compensation sample. The chirp parameter is a parameter transmitted by the ground station command generator 100 to the image radar 200 to perform the operation mode. The chirp parameter may include a chirp slope, a start frequency, a start phase, a length or pulse width of a sample, and the like.

The chirp sample calculating unit 30 calculates a chirp sample in which a phase error and a magnitude error are compensated by using the predistortion phase compensation sample and the predistortion magnitude compensation sample generated by the predistortion compensation sampler 20 . The chirp sample calculating unit 30 may calculate a chirp sample in which a phase error and a magnitude error are compensated by performing steps S130 to S160 of FIG. 2 to be described later, which will be described later with reference to FIG. 2 .

The chirp signal generator 220 converts the chirp sample through the digital-to-analog converter 40 while performing the operation mode to generate a chirp signal in which errors in the frequency domain and the time domain are compensated.

Hereinafter, a method for compensating for magnitude and phase errors of a chirp signal by the image radar illustrated in FIG. 1 in a memory-map method will be described with reference to FIG. 2 .

2 is a flowchart illustrating a method of compensating for magnitude and phase errors of a chirp signal in a memory-map method according to an embodiment of the present invention.

Referring to FIG. 2 , when the ground station command generator 100 uploads a chirp parameter for performing the operation mode, the image radar controller 210 uses the received chirp parameter and the error envelope sample table stored in the memory 10 . to generate a predistortion phase compensation sample (S110). Then, the image radar controller 210 generates a predistortion magnitude compensation sample using the chirp parameter and the error envelope sample table stored in the memory 10 ( S120 ).

The image radar controller 210 generates an optimal chirp phase sample using the chirp parameter (S130). An optimal chirp phase sample may be calculated by Equation (1).

는 최적 첩 위상 샘플이고, 는

첩 기울기이고,

는 시작 주파수이고,

은 시작 위상이고,

는 샘플의 길이 또는 펄스폭이다. here,

is the optimal chirp phase sample, and is

is the chirp slope,

is the starting frequency,

is the starting phase,

is the sample length or pulse width.

The image radar controller 210 may calculate the phase error-compensated chirp sample by adding the predistortion phase compensation sample to the optimal chirp phase sample ( S140 ).

The image radar controller 210 may input the phase error-compensated chirp sample into a trigonometric library of software or perform phase-magnitude conversion using a lookup table in which trigonometric magnitude values are calculated in advance for each phase ( S150).

A magnitude error-compensated chirp sample is calculated by multiplying the phase-magnitude-converted chirp sample by the predistortion magnitude compensation sample ( S160 ).

The calculated phase error-compensated chirp sample and the magnitude-error-compensated chirp sample are transmitted to the chirp signal generator 220 , and the chirp signal generator 220 generates a chirp signal in which the errors in the frequency domain and the time domain are compensated.

Hereinafter, an image radar compensating for a chirp signal by a direct digital synthesis (DDS) method will be described with reference to FIGS. 3 to 6 .

3 is a block diagram illustrating an image radar for compensating for magnitude and phase errors of a chirp signal by a direct digital synthesis method according to an embodiment of the present invention. 4 is a block diagram illustrating a predistortion compensation sample unit according to an embodiment of the present invention. 5 is an exemplary diagram illustrating an example of a process of generating a predistortion compensation sample. 6 is a block diagram illustrating a chirp signal generator according to an embodiment of the present invention.

3 to 6 , the image radar 200 includes an image radar controller 210 and a chirp signal generator 220 , and the image radar controller 210 includes a memory 10 , and a chirp signal generator ( 220 includes a predistortion compensation sampler 20 and a chirp signal generator 50 .

In the direct digital synthesis method, the image radar controller 210 transmits the received chirp parameter and the error envelope sample stored in the memory 10 to the chirp signal generator 220 before the operation mode is performed. The error envelope sample may include a frequency domain magnitude error envelope sample, a frequency domain phase error envelope sample, a time domain magnitude error envelope sample, and a time domain phase error envelope sample. And the chirp signal generator 220 generates a chirp signal in real time based on the information received while performing the operation mode.

The predistortion compensation sample unit 20 includes a first upsampling unit 21 , a second upsampling unit 22 , a first low pass filter 23 , a second low pass filter 24 , and a first number of samples adjusting unit (25), a second sample number adjusting unit 26 and an adder 27 are included.

A frequency domain magnitude (or phase) error envelope sample is input to the first upsampling unit 21 , and the first upsampling unit 21 receives a frequency domain magnitude (or phase) error envelope sample at a first upsampling ratio. up-sampling.

The first low-pass filter 23 interpolates the amplitude (or phase) error envelope samples of the upsampled frequency domain for each of the entire transmission signal samples. When the first upsampling ratio is M1, the pass band bandwidth of the first low-pass filter 23 is π/M1.

The first sample number adjusting unit 25 adjusts the amplitude (or phase) error envelope sample of the interpolated frequency domain to match the number of transmission samples and transmits it to the adder 27 .

A time domain magnitude (or phase) error envelope sample is input to the second upsampling unit 22 , and the second upsampling unit 22 receives a time domain magnitude (or phase) error envelope sample at a second upsampling ratio. upsamples the

The second low-pass filter 24 interpolates the upsampled time domain magnitude (or phase) error envelope samples for each of the entire transmission signal samples. If the second upsampling ratio is M2, the pass band bandwidth of the second low-pass filter 24 becomes π/M2. Since the number of error envelope samples in the time domain may be different from the number of error envelope samples in the frequency domain, the second upsampling ratio may be applied so that the number of samples of the transmission signal in the time domain matches the number of samples in the transmission signal in the frequency domain.

The second sample number adjusting unit 26 adjusts the size (or phase) error envelope sample of the interpolated time domain to the number of transmission samples and transmits the adjusted time domain sample to the adder 27 .

The adder 27 generates a predistortion magnitude (or phase) compensation sample by adding the magnitude (or phase) error envelope sample in the frequency domain and the magnitude (or phase) error envelope sample in the time domain.

5 illustrates a process of processing a phase error envelope sample in a frequency domain as a process by upsampling, interpolation using a pass filter, and adjusting the number of samples. In the same manner as in FIG. 5 , a process of processing the phase error envelope sample in the time domain may be performed by upsampling, interpolation using a pass filter, and adjusting the number of samples. A predistortion phase compensation sample may be generated by adding the processed frequency domain phase error envelope sample and the time domain phase error envelope sample. In addition, the frequency domain magnitude error envelope sample may be processed in the same manner as in FIG. 5, the time domain magnitude error envelope sample may be processed, and the processed frequency domain magnitude error envelope sample and the time domain magnitude error envelope sample may be obtained. In addition, a predistortion magnitude compensation sample may be generated.

The chirp signal generator 50 generates a chirp signal by using a chirp parameter, a predistortion phase compensation sample, and a predistortion magnitude compensation sample. The chirp signal generator 50 includes an optimal chirp phase sample generator 51 , an adder 52 , a phase-magnitude converter 53 , a multiplier 54 , and a digital-to-analog converter 55 .

The chirp parameter is input to the optimal chirped phase sample generating unit 51, and the optimal chirped phase sample generating unit 51 generates an optimal chirped phase sample corresponding to the chirped parameter. The optimal chirped phase sample generator 51 may generate an optimal chirped phase sample by simulating Equation 1 based on the phase accumulator.

The adder 52 adds the optimal chir phase sample and the predistortion phase compensation sample to generate a phase error-compensated chirp sample and inputs it to the phase-magnitude converter 53 .

The phase-magnitude converter 53 inputs the phase-error-compensated chirp sample into a trigonometric library of software or performs phase-magnitude transformation using a lookup table in which trigonometric magnitude values are calculated in advance for each phase.

The multiplier 54 multiplies the phase-magnitude-transformed chirp sample by the predistortion magnitude-compensated sample to generate magnitude-error-compensated chirp samples, which are input to the digital-to-analog converter 55 .

The digital-to-analog converter 55 converts the magnitude error-compensated chirp sample into an analog signal to generate a chirp signal for which errors in the frequency domain and time domain are compensated.

As described above, the proposed technique simultaneously applies frequency domain compensation and time domain compensation for predistortion. That is, when modeling errors caused by image radar equipment on the ground, equipment errors are divided into frequency domain error (time-invariant frequency response error, that is, signal error according to bandwidth) and time domain error (time-varying frequency response). It is a method of modeling by classifying the error, that is, the error of the signal according to the pulse width), and compensating for both the frequency-domain error and the time-domain error to the chirp signal when pre-distortion is performed.

The proposed technique is a method of modeling an error of a signal by equipment. It is an envelope sampling technique that samples and stores the envelope of the error for each of the magnitude and phase error of the frequency domain and the magnitude and phase error of the time domain. Typically, the number of samples required to model the error of the equipment is possible at the level of several tens (frequency domain error) or hundreds (time domain error) of the number of original signal samples. Through this, the envelope sampling technique can model the error much more accurately than the Taylor series modeling technique.

Since the amount of information is too large to upload the envelope samples generated by the envelope sampling technique from the ground station command generator 100 to the image radar 200 whenever the operation mode is performed, in the proposed technique, the envelope samples are stored in the memory of the image radar 200 . The method of saving in (10) is applied. That is, for the maximum bandwidth and maximum pulse width that a signal can have, envelope samples of the frequency domain error and time domain error are derived and stored in the memory 10 of the image radar 200, and the corresponding mode when the operation mode is performed. When the bandwidth and pulse width of the signal for , are raised by the ground station command generator 100, the image radar 200 cuts and applies the envelope sample according to the bandwidth and pulse width.

In addition, in the proposed technique, the interpolation filter technique is applied by calculating a predistortion value to be applied to all transmission signal samples from envelope samples. In general, polynomial methods (Lagrange method, Neville method, Newton polynomial method, etc.) are commonly used as interpolation methods. The amount of computation can be reduced by applying the interpolation filter technique.

The drawings and detailed description of the described invention referenced so far are merely exemplary of the present invention, which are only used for the purpose of explaining the present invention, and are used to limit the meaning or limit the scope of the present invention described in the claims. it is not Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be defined by the technical spirit of the appended claims.

10: memory
20: predistortion compensation sample unit
30: book sample calculation unit
40: digital-to-analog converter
50: chirp signal generation unit
100: Ground Station Command Generator
200: video radar
210: video radar controller
220: chirp signal generator

Claims (10)

an imaging radar controller that generates chirp samples prior to performing an operational mode; and
and a chirp signal generator for generating a chirp signal by converting the chirp sample while performing an operation mode,
The image radar controller,
a memory for storing an error envelope sample table including an error envelope sample in a frequency domain and an error envelope sample in a time domain;
a predistortion compensation sample unit for generating a predistortion phase compensation sample and a predistortion magnitude compensation sample using the chirp parameter transmitted from the ground station command generator and the error envelope sample table to perform the operation mode; and
and a chirp sample calculation unit for calculating a chirp sample in which a phase error and a magnitude error are compensated by using the predistortion phase compensation sample and the predistortion magnitude compensation sample,
The predistortion compensation sample unit upsamples the error envelope sample of the frequency domain by a first upsampling ratio, interpolates the upsampled error envelope sample of the frequency domain, and performs second upsampling of the error envelope sample of the time domain The predistortion phase compensation sample and the predistortion phase compensation sample and the transpose by upsampling at a rate, interpolating the upsampled time domain error envelope sample, and adding the interpolated frequency domain error envelope sample and the interpolated time domain error envelope sample Imaging radar generating distortion magnitude compensation samples. an imaging radar controller that generates chirp samples prior to performing an operational mode; and
and a chirp signal generator for generating a chirp signal by converting the chirp sample while performing an operation mode,
The image radar controller,
a memory for storing an error envelope sample table including an error envelope sample in a frequency domain and an error envelope sample in a time domain;
a predistortion compensation sample unit for generating a predistortion phase compensation sample and a predistortion magnitude compensation sample using the chirp parameter transmitted from the ground station command generator and the error envelope sample table to perform the operation mode; and
and a chirp sample calculation unit for calculating a chirp sample in which a phase error and a magnitude error are compensated by using the predistortion phase compensation sample and the predistortion magnitude compensation sample,
The image radar controller is

calculates an optimal chir phase sample with , and adds the predistortion phase compensation sample to the optimal chir phase sample to calculate a chirp sample for which a phase error is compensated,
remind

is the optimal chirp phase sample, and

is the chirp slope, and

is the starting frequency, and

is the starting phase, and

is the sample length or pulse width of the imaging radar. a chirp signal generator for generating a chirp signal based on information received while performing an operation mode; and
and a memory storing an error envelope sample table including an error envelope sample in the frequency domain and an error envelope sample in the time domain, wherein the chirp parameter and the error envelope sample in the frequency domain and the error envelope in the time domain before performing an operation mode an imaging radar controller that delivers a sample to the chirp signal generator;
The chirp signal generator,
a predistortion compensation sample unit for generating a predistortion phase compensation sample and a predistortion magnitude compensation sample using the chirp parameter, the error envelope sample in the frequency domain, and the error envelope sample in the time domain; and
a chir signal generator configured to generate the chirp signal by using the chirp parameter, the predistortion phase compensation sample, and the predistortion magnitude compensation sample;
The predistortion compensation sample unit,
a first upsampling unit for upsampling the error envelope sample in the frequency domain at a first upsampling ratio;
a first low-pass filter for interpolating an error envelope sample of the upsampled frequency domain;
a second upsampling unit for upsampling the error envelope sample in the time domain at a second upsampling ratio;
a second low-pass filter for interpolating the upsampled time-domain error envelope samples; and
and an adder configured to generate the predistortion phase compensation sample and the predistortion magnitude compensation sample by adding the interpolated frequency domain error envelope sample and the interpolated time domain error envelope sample. delete 4. The method of claim 3,
The predistortion compensation sample unit,
a first sample number adjusting unit that adjusts the error envelope samples of the interpolated frequency domain according to the number of transmission samples and transmits them to the adder; and
and a second sample number adjuster configured to adjust the interpolated time-domain error envelope samples according to the number of transmitted samples and transmit them to the adder. a chirp signal generator for generating a chirp signal based on information received while performing an operation mode; and
and a memory storing an error envelope sample table including an error envelope sample in the frequency domain and an error envelope sample in the time domain, wherein the chirp parameter and the error envelope sample in the frequency domain and the error envelope in the time domain before performing an operation mode an imaging radar controller that delivers a sample to the chirp signal generator;
The chirp signal generator,
a predistortion compensation sample unit for generating a predistortion phase compensation sample and a predistortion magnitude compensation sample using the chirp parameter, the error envelope sample in the frequency domain, and the error envelope sample in the time domain; and
a chir signal generator configured to generate the chirp signal by using the chirp parameter, the predistortion phase compensation sample, and the predistortion magnitude compensation sample;
The chirp signal generating unit,
an optimal chirped phase sample generator configured to generate an optimal chirped phase sample corresponding to the chirp parameter;
an adder for generating a phase error-compensated chirp sample by adding the optimal chir phase sample and the predistortion phase compensation sample;
a phase-magnitude converter configured to phase-magnify the phase-error-compensated chirp sample;
a multiplier for generating a magnitude error compensated chirp sample by multiplying the phase-magnitude-transformed chirp sample by the predistortion magnitude compensation sample; and
and a digital-analog converter for generating the chirp signal by converting the magnitude error-compensated chirp sample into an analog signal. generating a predistortion phase compensation sample using the chirp parameter and an error envelope sample table stored in a memory when the chirp parameter is received;
generating a predistortion magnitude compensation sample using the chirp parameter and the error envelope sample table;
generating an optimal chir phase sample corresponding to the chirp parameter;
calculating a phase error-compensated chirp sample by adding the predistortion phase compensation sample to the optimal chir phase sample;
phase-magnitude transforming the phase error-compensated chirp sample;
calculating a magnitude error-compensated chirp sample by multiplying the phase-magnitude-transformed chirp sample by the predistortion magnitude compensation sample; and
converting the magnitude error-compensated chirp sample into an analog signal to generate a chirp signal,
The error envelope sample table comprises an error envelope sample in a frequency domain and an error envelope sample in a time domain. delete 8. The method of claim 7,
The step of generating the predistortion phase compensation sample comprises:
upsampling the phase error envelope samples in the frequency domain at a first upsampling ratio;
interpolating a phase error envelope sample of the upsampled frequency domain;
upsampling the time domain phase error envelope samples at a second upsampling ratio;
interpolating the upsampled time domain phase error envelope samples; and
and generating the predistortion phase compensation sample by adding the interpolated frequency domain phase error envelope sample and the interpolated time domain phase error envelope sample. 8. The method of claim 7,
The step of generating the predistortion magnitude compensation sample comprises:
upsampling the amplitude error envelope sample in the frequency domain at a first upsampling ratio;
interpolating the amplitude error envelope samples of the upsampled frequency domain;
upsampling the time domain magnitude error envelope sample at a second upsampling ratio;
interpolating the upsampled time-domain magnitude error envelope samples; and
and generating the predistortion phase compensation sample by adding the interpolated frequency domain magnitude error envelope sample and the interpolated time domain magnitude error envelope sample.

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