CN111505618A - Decoupling correction ranging method based on frequency estimation and suitable for field of vehicle-mounted millimeter wave radar - Google Patents
Decoupling correction ranging method based on frequency estimation and suitable for field of vehicle-mounted millimeter wave radar Download PDFInfo
- Publication number
- CN111505618A CN111505618A CN202010289645.7A CN202010289645A CN111505618A CN 111505618 A CN111505618 A CN 111505618A CN 202010289645 A CN202010289645 A CN 202010289645A CN 111505618 A CN111505618 A CN 111505618A
- Authority
- CN
- China
- Prior art keywords
- frequency
- time dimension
- signal
- distance
- fast
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
- G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/50—Systems of measurement based on relative movement of target
- G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S13/583—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
- G01S13/584—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets adapted for simultaneous range and velocity measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
- G01S13/931—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/35—Details of non-pulse systems
- G01S7/352—Receivers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/35—Details of non-pulse systems
- G01S7/352—Receivers
- G01S7/356—Receivers involving particularities of FFT processing
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a decoupling correction distance measurement method based on frequency estimation, which is suitable for the field of vehicle-mounted millimeter wave radar and comprises the following steps that firstly, a complex modulation spectrum analysis technology is adopted to locally amplify a distance range concerned by people in a fast time dimension in combination with an actual application scene; then, aiming at the problem of coupling terms which are often ignored in the existing distance measurement scheme, distance-speed coupling and fast-time-slow-time coupling terms are removed through distance-Doppler two-dimensional combined processing and frequency domain interpolation correction, and the accuracy of distance measurement is further improved; in addition, the Jacobsen algorithm is adopted to carry out discrete spectrum correction, the accuracy is improved, meanwhile, the low calculation complexity and the real-time requirement are guaranteed, and the effectiveness and the performance superiority compared with other traditional schemes are proved by simulation results.
Description
Technical Field
The invention belongs to the field of radar signal processing, and particularly relates to a decoupling correction high-precision ranging method based on frequency estimation, which is suitable for the field of parameter estimation of a vehicle-mounted millimeter wave radar system.
Background
Typical advanced driver assistance applications such as Adaptive Cruise Control (ACC), Blind Spot Detection (BSD) and Forward Collision Warning (FCW) require high performance sensor based. Compared with other sensors such as a camera, an ultrasonic radar and a laser radar, the vehicle-mounted millimeter wave radar has an effect and a position which are difficult to replace in the field of unmanned driving due to small volume, low cost and all-weather adaptability, and is a hot point of research in academia and industry. Different transmitting waveforms have different characteristics and applicable scenes, and are main factors for determining the performance of the vehicle-mounted millimeter wave radar system. The linear frequency modulation continuous wave is relatively simple in signal generation and processing, can detect the distance and speed information of a target, does not have the distance blind area problem existing in a continuous wave radar, and is widely applied to vehicle-mounted millimeter wave radar products.
For a vehicle-mounted millimeter wave radar system, it is crucial to estimate the distance information of an object to be detected. In a vehicle-mounted FMCW system, a frequency estimation algorithm of Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT) is adopted, the operation speed is high, and the method has the advantages of remarkable signal-to-noise ratio gain, insensitivity of algorithm parameters and the like for sinusoidal signals. However, the ranging algorithm based on FFT peak frequency estimation also has some problems, which can be summarized as (1) the frequency estimation resolution of FFT is limited by the number of sampling points, and finite length FFT has the problems of barrier effect and sector loss. (2) The peak frequency obtained by FFT of the beat signal has problems of fast-slow time coupling and range-speed coupling, that is, even if the frequency estimation is accurate, the range information estimation is inaccurate. On one hand, the problems of the barrier effect, the fan loss and the like are all caused by the inherent characteristics of the FFT, and influence is caused on the frequency estimation and the amplitude estimation of the peak position. Another aspect is the fast time-slow time linear coupling term that the phase of the beat signal of a chirped continuous wave radar system has, and the range-velocity coupling term that the fast time dimension FFT results in the peak frequency, i.e. an accurate frequency estimate does not imply an accurate range estimate.
Disclosure of Invention
The purpose of the invention is as follows: in order to solve the problems in the ranging scheme, the invention provides a high-precision ranging scheme based on ZFT. The frequency spectrum of a beat signal is locally refined by using complex modulation band selection spectrum analysis (ZFT), and a frequency estimation value is further corrected by using three spectral line peak values with the largest frequency spectrum after ZFT through a Jacobsen algorithm, so that the measurement accuracy is improved, the calculation complexity is low, the real-time processing is convenient, and the hardware and time limitation of a vehicle-mounted FMCW radar system is well met. For the influence of the coupling term, on one hand, a distance Doppler two-dimensional processing method is adopted, the unambiguous velocity information is extracted through slow time dimension FFT and ambiguity resolution processing, and the unambiguous velocity is used for distance velocity decoupling. On the other hand, aiming at the coupling of fast time and slow time, the phenomenon that the peak frequency of the fast time dimension shifts along with the slow time is solved by an interpolation correction method. On one hand, the distance information corresponding to frequency estimation is more accurate through correction of the coupling term, and meanwhile, the signal-to-noise ratio gain of two-dimensional FFT is improved, and the method is beneficial to the subsequent steps of arrival angle estimation and the like.
The technical scheme is as follows: a decoupling correction ranging method based on frequency estimation and suitable for the field of vehicle-mounted millimeter wave radars comprises the following steps:
step 1: establishing a mathematical model of echo signals of the millimeter wave vehicle-mounted radar system to obtain expressions of transmitting signals, receiving signals and beat signals;
step 2: the method comprises the steps that an orthogonal double-channel receiving signal is adopted by a system to be considered, discrete sampling is carried out on the orthogonal double-channel receiving signal, and a discrete form y (m, n) of a complex beat signal is obtained under the condition that a coupling term is considered;
and step 3: carrying out fast time dimension complex modulation spectrum analysis (ZFT) on the discrete form complex beat signal obtained in the step (2) to obtain a complex beat signal Y (k, n) after spectrum refinement;
and 4, step 4: correcting the coupling of the fast time dimension and the slow time dimension in the fast time dimension by utilizing a simplified frequency domain correction scheme on the Y (k, n) obtained in the step 3;
and 5: for the complex beat signal obtained in step 4 after removing the coupling term in the fast-slow time dimensionThe Jacobsen algorithm is adopted, three spectral lines with the largest FFT frequency spectrum are used for correcting the fast time dimension peak frequency corresponding to the target distance to a certain degree, and the corrected fast time dimension peak frequency is obtained
Step 6: performing a slow time dimension FFT operation on the echo signal, using the peak frequency of the slow time dimensionAnd (5) correcting the distance-speed coupling to obtain a final distance estimation value.
Further, in step 1, a mathematical model of an echo signal of the millimeter wave vehicle-mounted radar system is established to obtain expressions of a transmitting signal, a receiving signal and a beat signal, and the method comprises the following steps:
the wave form of the transmitting signal of the millimeter wave vehicle-mounted radar system is a group of carrier frequency f0In the transmitting period, a plurality of transmitting antennas transmit linear frequency modulation continuous wave signals with certain frequency sweep bandwidth in a time-sharing mode in sequence, and at the time t, the ith frequency sweep period transmits a signal xt(t, i) the expression is:
wherein, i is 1,2Sa,A,f0,Respectively, amplitude of transmitted signal, carrier frequency and initial phase,μ=B0T is the chirp rate, B0Is the sweep bandwidth, T is the period of a chirp continuous wave, NsaWhen t is 0, the radial distance from the target vehicle in front of the radar is r, the target with the radial speed v is positive in the direction in which the radial speed and the radar distance are decreasing, so that the received signal x isrThe expression of (t, i) can be written as:
wherein A is0Is the amplitude of the received signal, τ is 2(r-vt)/c is the time delay caused by the distance between the target and the radar, c is the speed of light, the received signal and the original transmitting signal are mixed, and the intermediate frequency signal, also called beat signal, is obtained by the low-pass filter, at time t, the expression y of the i-th periodic beat signali(t) can be written as:
time η -t-iT within a single transmission period is referred to as fast time η, the time between different transmission periodsReferred to as slow time, the above equation can be organized as:
if in the above formula c is considered-2Andif the term is negligible, then the fast time dimension is FFT, resulting in fast time dimension peak frequencies for r and v as:
similarly, if the FFT is performed on the slow time dimension, the peak frequency of the slow time dimension with respect to v is obtained as:
further, in step 2, the system is considered to adopt the orthogonal dual-channel received signal, and discrete sampling is performed on the orthogonal dual-channel received signal, so as to obtain a discrete form y (m, n) of the complex beat signal under the condition that the coupling term is considered, and the method is as follows:
obtained from step 1The expression of (b) shows that the coupling can be divided into two aspects, namely distance-velocity coupling: distance and velocity coupling term of-2 vf0The other side is fast time slow time coupling: the fast-time and slow-time coupling is mainly formed byInDue to the term, we only consider hereWhile not counting η2Influence of item because of η2The presence of the term mainly has an effect on the fast time FFT itself, independent of coupling.
Considering the number of fast time dimension sampling points as N for a single sawtooth wave frequency sweep periodsTransmitting N within one coherent processing cyclesaNumber of sampling points in sawtooth, i.e. slow time dimension, NsaConsider that the system uses an orthogonal two-channel received signal, which is orthogonally transformed to obtain a discrete form y (m, n) of the complex beat signal under consideration of the coupling term:
in the formula (I), the compound is shown in the specification,is a constant independent of time, fs=T/NsIs the sampling frequency of the fast time dimension, f s11/T is the sampling frequency of the slow time dimension, fc-2 μ v/c is the coefficient of the fast time slow time coupling term.
Further, in step 3, fast time-dimension complex modulation spectrum analysis (ZFFT) is performed on the discrete-form complex beat signal Y (m, n) obtained in step 2 to obtain a complex beat signal Y (k, n) after spectrum refinement, and the method is as follows:
(3.1) Complex modulation Shift frequency
In the millimeter wave vehicle-mounted radar system, the distance between the target and the radar is usually within a specific distance range, or the linear distance range between the target and the vehicle-mounted radar can be judged through other prior information, and the fast time dimension peak frequency corresponding to the distance range is f1~f2If the center frequency of the band to be observed is fm=(f2-f1) 2, for the complex beat signal y (m, n)Carrying out complex modulation to obtain a frequency shift signal y1(m,n):
Wherein Y (k, n) is a frequency domain signal corresponding to Y (m, n),center frequency fmCorresponding line number Lc=fmA/Δ f, a line spacing Δ f ═ fs/NsTherefore, the discrete Fourier change Y of the signal after complex modulation is determined by the frequency shift property of DFT1(k, n) should satisfy:
Y1(k,n)=Y(k+Lc,n)
that is to say the centre frequency f after complex modulationmShifted to zero frequency;
(3.2) Low pass Filtering
In order to prevent aliasing of a frequency band component of interest by an unnecessary frequency band caused after a reduction in sampling frequency, anti-aliasing filtering is first required, and a frequency refinement multiple D ═ f is defineds/(f2-f1) The cut-off frequency of the low-pass filter is fe=fs2D, where the output of the filter is:
where h (k) is the frequency response function of an ideal low-pass filter, the time domain signal output by the filter is:
(3.3) resampling
To obtain Y2The part of the refined frequency spectrum near the (k, n) zero frequency can be reduced to f by adopting a resampling modesThe original sampling points are sampled once every D (D is a positive integer), and the expression of the re-sampled signal is y3(m,n)=y2(Dm,n);
(3.4) Complex FFT processing
N is carried out on the resampled signalsFFT of the points, get y3(m, n) has a frequency spectrum of
(3.5) spectral modification
The obtained NsShifting the frequency of the strip spectral line to the actual frequency to obtain a frequency band after ZFFT refinement:
from the above formula, it can be seen that the analysis of the complex frequency modulation refining band selection spectrum reflects that the local refining is performed in a certain frequency range, and the reduction of the distance measurement precision caused by the fence effect is compensated under the condition of not increasing the number of sampling points.
Further, in step 4, the Y (k, n) obtained in step 3 is corrected in the fast time dimension by using a simplified frequency domain correction scheme, and the method is as follows:
from the step (3.5), it can be seen that the N is obtained after the complex modulation band selection analysis ZFFT is subjected to spectral line adjustmentsObtaining N after direct pair fast time dimension FFT of root spectral linesThe discrete spectral lines are the same, so the expression of Y (k, n) in step 3 can be calculated as follows:
in the above formula, sa (x) represents a sampling function, which is defined as sa (x) sin (x)/x, and it can be seen from the above formula that the FFT is followed by the FFT in the fast time dimensionWhen the peak position of (a) is ω ═ 0, the deviation Δ k (N) of the peak position due to coupling and the fast time are in a linear relationship, and the slope is Nsfc/fsfs1。
The peak position deviation delta k (n) is corrected by replacing Y (k, n) with Y (k + delta k (n), the influence of a coupling term is eliminated by sampling a sinc function interpolation mode, and the interpolated signal is called asThe formula for interpolation of the sinc function along the fast time dimension is:
in the formula
And round [. C]Rounding, P is the number of sinc interpolation kernels, if the interpolation result is accurate, thenThe expression of (a) is approximately written as:
further, in step 5, the complex beat signal obtained in step 4 after removing the coupling term in the fast time-slow time dimension is processedThe Jacobsen algorithm is adopted, three spectral lines with the largest FFT frequency spectrum are used for correcting the fast time dimension peak frequency corresponding to the target distance to a certain degree, and the corrected fast time dimension peak frequency is obtainedThe method comprises the following steps:
recording the received signal after the coupling correctionMaximum spectral line position number kdRepresenting the relative deviation of the actual peak frequency of the fast time dimension of the received signal from the corresponding frequency of the maximum spectral line, the actual peak frequency f of the fast time dimension of the signalr,vCan be expressed as fr,v=(kd+)fs/NsThen, according to the Jacobsen algorithm, the relative deviation estimation of the actual peak frequency of the received signal in the fast time dimension and the frequency corresponding to the maximum spectral lineCan be calculated using the following formula:
in the formula, real (-) is operated to obtain the real peak frequency f of the signalr,vIs estimated value ofCan be written as:
further, in step 6, a slow time dimension FFT operation is performed on the echo signal, and the peak frequency f of the slow time dimension is utilizedvAnd (3) correcting the distance-velocity coupling to obtain a final distance estimation value, wherein the method comprises the following steps:
(6.1) performing slow time dimension FFT on the received echo signals processed in the step 1-5 to obtain a peak frequency estimation of the slow time dimension
(6.2) utilizing the fast time dimension peak frequency estimation value obtained in the step 5And (6.1) Peak frequency estimation in the Slow time dimension
(6.3) obtaining the unambiguous speed estimation of the target by using a multi-frequency or multi-carrier equal speed ambiguity resolution method
(6.4) utilization ofDecoupling correction is carried out on the distance to obtain the final distance estimation
Has the advantages that: compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:
the invention discloses a decoupling correction high-precision distance measurement method technology based on frequency estimation, which is suitable for the field of parameter estimation of vehicle-mounted millimeter wave radar systems. The simulation result proves the effectiveness and the performance superiority compared with other traditional schemes.
Drawings
FIG. 1 shows the variation of the miss-detection rate with distance in the embodiment of the present invention, with a target speed of 10 m/s;
FIG. 2 is a diagram showing the variation of the undetected rate with distance according to the embodiment of the present invention, wherein the target speed is 40 m/s;
FIG. 3 is a diagram illustrating the variation of the average error of distance estimation with distance according to an embodiment of the present invention, wherein the target speed is 10 m/s;
FIG. 4 shows the average error of the distance estimation as a function of the distance according to the embodiment of the present invention, and the target speed is 40 m/s.
Detailed Description
The present invention is further illustrated by the following examples, which are intended to be purely exemplary of the invention and are not intended to limit its scope, as various equivalent modifications of the invention will become apparent to those skilled in the art after reading the present invention and fall within the scope of the appended claims.
The invention provides a decoupling correction ranging method based on frequency estimation, which is suitable for the field of vehicle-mounted millimeter wave radars and comprises the following steps:
step 1: establishing a mathematical model of echo signals of the millimeter wave vehicle-mounted radar system to obtain expressions of transmitting signals, receiving signals and beat signals;
step 2: the method comprises the steps that an orthogonal double-channel receiving signal is adopted by a system to be considered, discrete sampling is carried out on the orthogonal double-channel receiving signal, and a discrete form y (m, n) of a complex beat signal is obtained under the condition that a coupling term is considered;
and step 3: carrying out fast time dimension complex modulation spectrum analysis (ZFT) on the discrete form complex beat signal obtained in the step (2) to obtain a complex beat signal Y (k, n) after spectrum refinement;
and 4, step 4: correcting the coupling of the fast time dimension and the slow time dimension in the fast time dimension by utilizing a simplified frequency domain correction scheme on the Y (k, n) obtained in the step 3;
and 5: for the complex beat signal obtained in step 4 after removing the coupling term in the fast-slow time dimensionAdopting a Jacobsen algorithm, and utilizing three spectral lines with maximum FFT frequency spectrum to align the target distanceCorrecting to a certain extent from the corresponding fast time dimension peak frequency to obtain the corrected fast time dimension peak frequency
Step 6: performing a slow time dimension FFT operation on the echo signal, using the peak frequency of the slow time dimensionAnd (5) correcting the distance-speed coupling to obtain a final distance estimation value.
Further, in step 1, a mathematical model of an echo signal of the millimeter wave vehicle-mounted radar system is established to obtain expressions of a transmitting signal, a receiving signal and a beat signal, and the method comprises the following steps:
the wave form of the transmitting signal of the millimeter wave vehicle-mounted radar system is a group of carrier frequency f0In the transmitting period, a plurality of transmitting antennas transmit linear frequency modulation continuous wave signals with certain frequency sweep bandwidth in a time-sharing mode in sequence, and at the time t, the ith frequency sweep period transmits a signal xt(t, i) the expression is:
wherein, i is 1,2Sa,A,f0,Respectively, amplitude of the transmitted signal, carrier frequency and initial phase, mu ═ B0T is the chirp rate, B0Is the sweep bandwidth, T is the period of a chirp continuous wave, NsaWhen t is 0, the radial distance from the target vehicle in front of the radar is r, the target with the radial speed v is positive in the direction in which the radial speed and the radar distance are decreasing, so that the received signal x isrThe expression of (t, i) can be written as:
wherein A is0Is the amplitude of the received signal, τ is 2(r-vt)/c is the time delay caused by the distance between the target and the radar, c is the speed of light, the received signal and the original transmitting signal are mixed, and the intermediate frequency signal, also called beat signal, is obtained by the low-pass filter, at time t, the expression y of the i-th periodic beat signali(t) can be written as:
time η -t-iT within a single transmission period is referred to as fast time η, the time between different transmission periodsReferred to as slow time, the above equation can be organized as:
if in the above formula c is considered-2Andif the term is negligible, then the fast time dimension is FFT, resulting in fast time dimension peak frequencies for r and v as:
similarly, if the FFT is performed on the slow time dimension, the peak frequency of the slow time dimension with respect to v is obtained as:
further, in step 2, the system is considered to adopt the orthogonal dual-channel received signal, and discrete sampling is performed on the orthogonal dual-channel received signal, so as to obtain a discrete form y (m, n) of the complex beat signal under the condition that the coupling term is considered, and the method is as follows:
obtained from step 1The expression of (b) shows that the coupling can be divided into two aspects, namely distance-velocity coupling: distance and velocity coupling term of-2 vf0The other side is fast time slow time coupling: the fast-time and slow-time coupling is mainly formed byInDue to the term, we only consider hereWhile not counting η2Influence of item because of η2The presence of the term mainly has an effect on the fast time FFT itself, independent of coupling.
Considering the number of fast time dimension sampling points as N for a single sawtooth wave frequency sweep periodsTransmitting N within one coherent processing cyclesaNumber of sampling points in sawtooth, i.e. slow time dimension, NsaConsider that the system uses an orthogonal two-channel received signal, which is orthogonally transformed to obtain a discrete form y (m, n) of the complex beat signal under consideration of the coupling term:
in the formula (I), the compound is shown in the specification,is a constant independent of time, fs=T/NsIs the sampling frequency of the fast time dimension, f s11/T is the sampling frequency of the slow time dimension, fc-2 μ v/c is the coefficient of the fast time slow time coupling term.
Further, in step 3, fast time-dimension complex modulation spectrum analysis (ZFFT) is performed on the discrete-form complex beat signal Y (m, n) obtained in step 2 to obtain a complex beat signal Y (k, n) after spectrum refinement, and the method is as follows:
(3.1) Complex modulation Shift frequency
In the millimeter wave vehicle-mounted radar system, the distance between the target and the radar is usually within a specific distance range, or the linear distance range between the target and the vehicle-mounted radar can be judged through other prior information, and the fast time dimension peak frequency corresponding to the distance range is f1~f2If the center frequency of the band to be observed is fm=(f2-f1) 2, to complex beat signalCarrying out complex modulation to obtain a frequency shift signal y1(m,n):
Wherein Y (k, n) is a frequency domain signal corresponding to Y (m, n),center frequency fmCorresponding line number Lc=fmA/Δ f, a line spacing Δ f ═ fs/NsTherefore, the discrete Fourier change Y of the signal after complex modulation is determined by the frequency shift property of DFT1(k, n) should satisfy:
Y1(k,n)=Y(k+Lc,n)
that is to say the centre frequency f after complex modulationmShifted to zero frequency;
(3.2) Low pass Filtering
In order to prevent aliasing of a frequency band component of interest by an unnecessary frequency band caused after a reduction in sampling frequency, anti-aliasing filtering is first required, and a frequency refinement multiple D ═ f is defineds/(f2-f1) The cut-off frequency of the low-pass filterIs fe=fs2D, where the output of the filter is:
where h (k) is the frequency response function of an ideal low-pass filter, the time domain signal output by the filter is:
(3.3) resampling
To obtain Y2The part of the refined frequency spectrum near the (k, n) zero frequency can be reduced to f by adopting a resampling modesThe original sampling points are sampled once every D (D is a positive integer), and the expression of the re-sampled signal is y3(m,n)=y2(Dm,n);
(3.4) Complex FFT processing
N is carried out on the resampled signalsFFT of the points, get y3(m, n) has a frequency spectrum of
(3.5) spectral modification
The obtained NsShifting the frequency of the strip spectral line to the actual frequency to obtain a frequency band after ZFFT refinement:
from the above formula, it can be seen that the analysis of the complex frequency modulation refining band selection spectrum reflects that the local refining is performed in a certain frequency range, and the reduction of the distance measurement precision caused by the fence effect is compensated under the condition of not increasing the number of sampling points.
Further, in step 4, the Y (k, n) obtained in step 3 is corrected in the fast time dimension by using a simplified frequency domain correction scheme, and the method is as follows:
from the step (3.5), it can be seen that the N is obtained after the complex modulation band selection analysis ZFFT is subjected to spectral line adjustmentsObtaining N after direct pair fast time dimension FFT of root spectral linesThe discrete spectral lines are the same, so the expression of Y (k, n) in step 3 can be calculated as follows:
in the above formula, sa (x) represents a sampling function, which is defined as sa (x) sin (x)/x, and it can be seen from the above formula that the FFT is followed by the FFT in the fast time dimensionWhen the peak position of (a) is ω ═ 0, the deviation Δ k (N) of the peak position due to coupling and the fast time are in a linear relationship, and the slope is Nsfc/fsfs1。
The peak position deviation delta k (n) is corrected by replacing Y (k, n) with Y (k + delta k (n), the influence of a coupling term is eliminated by sampling a sinc function interpolation mode, and the interpolated signal is called asThe formula for interpolation of the sinc function along the fast time dimension is:
in the formula
And round [. C]Rounding, P is the number of sinc interpolation kernels, if the interpolation result is accurate, thenThe expression of (a) is approximately written as:
further, in step 5, the complex beat signal obtained in step 4 after removing the coupling term in the fast time-slow time dimension is processedThe Jacobsen algorithm is adopted, three spectral lines with the largest FFT frequency spectrum are used for correcting the fast time dimension peak frequency corresponding to the target distance to a certain degree, and the corrected fast time dimension peak frequency is obtainedThe method comprises the following steps:
recording the received signal after the coupling correctionMaximum spectral line position number kdRepresenting the relative deviation of the actual peak frequency of the fast time dimension of the received signal from the corresponding frequency of the maximum spectral line, the actual peak frequency f of the fast time dimension of the signalr,vCan be expressed as fr,v=(kd+)fs/NsThen, according to the Jacobsen algorithm, the relative deviation estimation of the actual peak frequency of the received signal in the fast time dimension and the frequency corresponding to the maximum spectral lineCan be calculated using the following formula:
in the formula, real (-) is operated to obtain the real peak frequency f of the signalr,vIs estimated value ofCan be written as:
further, in step 6, a slow time dimension FFT operation is performed on the echo signal, and the peak frequency f of the slow time dimension is utilizedvAnd (3) correcting the distance-velocity coupling to obtain a final distance estimation value, wherein the method comprises the following steps:
(6.1) performing slow time dimension FFT on the received echo signals processed in the step 1-5 to obtain a peak frequency estimation of the slow time dimension
(6.2) utilizing the fast time dimension peak frequency estimation value obtained in the step 5And (6.1) Peak frequency estimation in the Slow time dimension
(6.3) obtaining the unambiguous speed estimation of the target by using a multi-frequency or multi-carrier equal speed ambiguity resolution method
(6.4) utilization ofDecoupling correction is carried out on the distance to obtain the final distance estimation
In the part, a target distance estimation simulation platform is built according to actual vehicle-mounted millimeter wave radar system parameters to verify the effectiveness of the proposed high-precision ranging algorithm. The performance of four different ranging schemes is compared, the first scheme is a decoupling correction high-precision ranging method based on frequency estimation and suitable for the field of parameter estimation of vehicle-mounted millimeter wave radar systems, the second scheme is different from the first scheme in that a Jacobsen algorithm is not adopted to compensate straddle loss, the third scheme is that distance estimation is carried out only by adopting a frequency spectrum peak value after complex modulation band selection analysis, and the fourth scheme is that distance estimation is carried out directly through FFT peak value frequency. Other system parameters of the four schemes are the same, and main simulation parameter settings of the system are shown in table 1. The range of the target is 30-90m, the azimuth angle and the elevation angle are 10 degrees and 0 degree respectively, and the radar scattering sectional area is 30 dBsm. We analyzed and compared the performance of the four solution distance estimation solutions at target speeds of 10m/s and 40m/s, respectively.
Table 1: system parameter setting
FIG. 1 and FIG. 2 show the variation of the false drop rate of a target with distance when the target speed is 10m/s and 40m/s, respectively. As can be seen from fig. 1, when the target speed is relatively small, the influence on the distance estimation is relatively small, and the target missed detection rates of the four ranging schemes are all maintained at a relatively low probability. The difference of the missed detection rate between the four ranging schemes is small, and the missed detection rate of the original ranging scheme is slightly higher than that of the other schemes only after the position of the target exceeds 70m (when the amplitude of the received signal is small). Meanwhile, as can be seen from fig. 2, when the target speed is high, due to the coupling of the fast time and the slow time dimension, for different slow time dimension units, the peak frequency after fast time dimension FFT falls on different distance units, and the larger the speed is, the more obvious the distance migration phenomenon is, the level of the accumulated signal-to-noise ratio after two-dimensional FFT deteriorates, and further the constant false alarm detection cannot be passed. The omission factor of the original scheme is greatly increased, and the omission factor reaches 20% when the target is far away. Meanwhile, thanks to the frequency band refinement and decoupling operations, the signal-to-noise ratio degradation phenomena of other distance estimation schemes are relieved and compensated to a certain extent, so that the missed detection rates of the other three distance measurement schemes are generally maintained at a very low probability, and the performance superiority of the high-precision distance measurement scheme provided by the invention is not very obvious from the viewpoint of the missed detection rate.
FIG. 3 and FIG. 4 show the average error of distance estimation as a function of distance for target speeds of 10m/s and 40m/s, respectively. On one hand, as can be seen from the comparison between fig. 3 and fig. 4, when the target speed is relatively small, the average ranging errors of the four ranging schemes are relatively small, and the difference between the ranging errors of the schemes is relatively small. It is explained that the estimation of the target distance parameter in the vehicle-mounted millimeter wave radar system is related to the target speed, and the larger the speed is, the larger the influence on the distance estimation is. On the other hand, as can be seen from fig. 3 or fig. 4, the ranging scheme proposed herein has the smallest ranging average error, and the performance is improved significantly compared to the original scheme of performing the range estimation through the peak frequency. The complex modulation spectrum refinement, the coupling correction and the Jacobsen algorithm play a role in more accurately measuring the distance, and the coupling correction plays a most obvious role in improving the distance measuring performance. This is because both the complex modulation band-select analysis and the Jacobsen algorithm are essentially improvements to the FFT algorithm, solving the problem of the fence effect or the fan-shaped loss, and the space for improvement is limited when the spectral resolution of the system itself is high. The coupling correction technology solves the problems of range migration and main lobe widening for the correction of fast time and slow time coupling and improves the accumulated signal-to-noise ratio, and the correction for the distance speed coupling is a feedback correction for the original distance estimation, the coupling distance is firstly obtained, and then the compensation is carried out through the accurate estimation of the speed parameter. The correction operation of the coupling term can be performed from the simulation result, which is particularly important when the target speed is high. In the vehicle-mounted millimeter wave radar system, the speed of the target is usually the relative speed between the vehicle to be detected and the target, and the speed range can reach-30 m/s to 60m/s, so that it is necessary to adopt the improved ranging scheme proposed herein to perform more accurate ranging in the speed range.
Claims (7)
1. A decoupling correction ranging method based on frequency estimation and suitable for the field of vehicle-mounted millimeter wave radars is characterized by comprising the following steps:
step 1: establishing a mathematical model of echo signals of the millimeter wave vehicle-mounted radar system to obtain expressions of transmitting signals, receiving signals and beat signals;
step 2: the method comprises the steps that an orthogonal double-channel receiving signal is adopted by a system to be considered, discrete sampling is carried out on the orthogonal double-channel receiving signal, and a discrete form y (m, n) of a complex beat signal is obtained under the condition that a coupling term is considered;
and step 3: carrying out fast time-dimensional complex modulation spectrum analysis on the discrete complex beat signal obtained in the step 2 to obtain a complex beat signal Y (k, n) after spectrum refinement;
and 4, step 4: correcting the coupling of the fast time dimension and the slow time dimension in the fast time dimension by utilizing a simplified frequency domain correction scheme on the Y (k, n) obtained in the step 3;
and 5: for the complex beat signal obtained in step 4 after removing the coupling term in the fast-slow time dimensionThe Jacobsen algorithm is adopted, three spectral lines with the largest FFT frequency spectrum are used for correcting the fast time dimension peak frequency corresponding to the target distance to a certain degree, and the corrected fast time dimension peak frequency is obtained
2. The decoupling correction ranging method based on frequency estimation applicable to the field of vehicle-mounted millimeter wave radars as claimed in claim 1, wherein in step 1, a mathematical model of echo signals of a millimeter wave vehicle-mounted radar system is established to obtain expressions of transmitting signals, receiving signals and beat signals, and the method comprises the following steps: the wave form of the transmitting signal of the millimeter wave vehicle-mounted radar system is a group of carrier frequency f0In the transmitting period, a plurality of transmitting antennas transmit linear frequency modulation continuous wave signals with certain frequency sweep bandwidth in a time-sharing mode in sequence, and at the time t, the ith frequency sweep period transmits a signal xt(t, i) the expression is:
wherein, i is 1,2Sa,A,f0,Respectively, amplitude of the transmitted signal, carrier frequency and initial phase, mu ═ B0T is the chirp rate, B0Is the sweep bandwidth, T is the period of a chirp continuous wave, NsaWhen t is 0, the radial distance from the target vehicle in front of the radar is r, the target with the radial speed v is positive in the direction in which the radial speed and the radar distance are decreasing, so that the received signal x isrThe expression of (t, i) can be written as:
wherein A is0Is the amplitude of the received signal, τ is 2(r-vt)/c is the time delay caused by the distance between the target and the radar, c is the speed of light, the received signal and the original transmitting signal are mixed, and the intermediate frequency signal, also called beat signal, is obtained by the low-pass filter, at time t, the expression y of the i-th periodic beat signali(t) can be written as:
time η -t-iT within a single transmission period is referred to as fast time η, the time between different transmission periodsReferred to as slow time, the above equation can be organized as:
if in the above formula c is considered-2Andif the term is negligible, then the fast time dimension is FFT, resulting in fast time dimension peak frequencies for r and v as:
similarly, if the FFT is performed on the slow time dimension, the peak frequency of the slow time dimension with respect to v is obtained as:
3. the decoupling correction ranging method based on frequency estimation in the field of vehicle-mounted millimeter wave radar according to claim 2, wherein in the step 2, the system is considered to adopt orthogonal dual-channel received signals, and discrete sampling is performed on the signals, so as to obtain the discrete form y (m, n) of the complex beat signal under the condition that the coupling term is considered, and the method is as follows:
obtained from step 1The expression of (b) shows that the coupling can be divided into two aspects, namely distance-velocity coupling: distance and velocity coupling term of-2 vf0The other side is fast time slow time coupling: the fast-time and slow-time coupling is mainly formed byInCaused by an item, only considerWhile not counting η2The influence of the item;
considering the number of fast time dimension sampling points as N for a single sawtooth wave frequency sweep periodsTransmitting N within one coherent processing cyclesaNumber of sampling points in sawtooth, i.e. slow time dimension, NsaConsider that the system uses an orthogonal two-channel received signal, which is orthogonally transformed to obtain a discrete form y (m, n) of the complex beat signal under consideration of the coupling term:
4. The decoupling correction ranging method based on frequency estimation in the field of vehicle-mounted millimeter wave radar as claimed in claim 3, wherein in step 3, fast time-dimension complex modulation spectrum analysis (ZFFT) is performed on the discrete complex beat signal Y (m, n) obtained in step 2 to obtain the complex beat signal Y (k, n) after spectrum refinement, and the method is as follows:
(3.1) Complex modulation Shift frequency
Judging the linear distance range between the target and the vehicle-mounted radar through prior information, wherein the fast time dimension peak frequency corresponding to the distance range is f1~f2If the center frequency of the band to be observed is fm=(f2-f1) 2, for the complex beat signal y (m, n)Carrying out complex modulation to obtain a frequency shift signal y1(m,n):
Wherein Y (k, n) is a frequency domain signal corresponding to Y (m, n),center frequency fmCorresponding line number Lc=fmA/Δ f, a line spacing Δ f ═ fs/NsTherefore, the discrete Fourier change Y of the signal after complex modulation is determined by the frequency shift property of DFT1(k, n) should satisfy:
Y1(k,n)=Y(k+Lc,n)
that is to say the centre frequency f after complex modulationmShifted to zero frequency;
(3.2) Low pass Filtering
Firstly, anti-aliasing filtering is needed, and a frequency refinement multiple D ═ f is defineds/(f2-f1) The cut-off frequency of the low-pass filter is fe=fs2D, where the output of the filter is:
where h (k) is the frequency response function of an ideal low-pass filter, the time domain signal output by the filter is:
(3.3) resampling
To obtain Y2The part of the refined frequency spectrum near the (k, n) zero frequency can be reduced to f by adopting a resampling modesD, namely resampling the original sampling points every D, wherein D is a positive integer, and obtaining a resampled signal expression y3(m,n)=y2(Dm,n);
(3.4) Complex FFT processing
N is carried out on the resampled signalsFFT of the points, get y3The spectrum of (m, n) is:
(3.5) spectral modification
The obtained NsShifting the frequency of the strip spectral line to the actual frequency to obtain a frequency band after ZFFT refinement:
5. the decoupling calibration method based on frequency estimation applied to the field of vehicle-mounted millimeter wave radar according to claim 4A positive high-precision method, characterized in that in step 4, a simplified frequency domain correction scheme is used for Y (k, n) obtained in step 3, and correction of fast-time-slow-time dimension coupling is performed in the fast-time dimension, the method being as follows: from the step (3.5), it can be seen that the N is obtained after the complex modulation band selection analysis ZFFT is subjected to spectral line adjustmentsObtaining N after direct pair fast time dimension FFT of root spectral linesThe discrete spectral lines are the same, so the expression of Y (k, n) in step 3 can be calculated as follows:
in the above formula, sa (x) represents a sampling function, which is defined as sa (x) sin (x)/x, and it can be seen from the above formula that the FFT is performed in the fast time dimensionWhen the peak position of (a) is ω ═ 0, the deviation Δ k (N) of the peak position due to coupling and the fast time are in a linear relationship, and the slope is Nsfc/fsfs1;
The peak value position deviation delta k (n) is corrected by replacing Y (k, n) with Y (k + delta k (n), the influence of a coupling term is eliminated by sampling a sinc function interpolation mode, and the interpolated signal is called asThe formula for interpolation of the sinc function along the fast time dimension is:
in the formula
And round [. C]Rounding, P is the number of sinc interpolation kernels, if the interpolation result is accurate, thenThe expression of (a) is approximately written as:
6. the decoupling correction ranging method based on frequency estimation in the field of vehicle-mounted millimeter wave radar as claimed in claim 5, wherein in step 5, the complex beat signal obtained in step 4 after the fast-slow time dimension coupling term is removed is subjected to the stepThe Jacobsen algorithm is adopted, three spectral lines with the largest FFT frequency spectrum are used for correcting the fast time dimension peak frequency corresponding to the target distance to a certain degree, and the corrected fast time dimension peak frequency is obtainedThe method comprises the following steps: recording the received signal after the coupling correctionMaximum spectral line position number kdRepresenting the relative deviation of the actual peak frequency of the fast time dimension of the received signal from the corresponding frequency of the maximum spectral line, the actual peak frequency f of the fast time dimension of the signalr,vCan be expressed as fr,v=(kd+)fs/NsThen, according to the Jacobsen algorithm, the relative deviation estimation of the actual peak frequency of the received signal in the fast time dimension and the frequency corresponding to the maximum spectral lineCan be calculated using the following formula:
in the formula, real (-) is operated to obtain the real peak frequency f of the signalr,vIs estimated value ofCan be written as:
7. the decoupling correction high-precision ranging method based on frequency estimation in the field of parameter estimation of millimeter wave radar systems on vehicles according to claim 6, wherein in step 6, a slow time dimension FFT operation is performed on the echo signal, and a peak frequency f of the slow time dimension FFT operation is utilizedvAnd (3) correcting the distance-velocity coupling to obtain a final distance estimation value, wherein the method comprises the following steps:
(6.1) performing slow time dimension FFT on the received echo signals processed in the step 1-5 to obtain a peak frequency estimation of the slow time dimension
(6.2) utilizing the fast time dimension peak frequency estimation value obtained in the step 5And (6.1) Peak frequency estimation in the Slow time dimensionCalculating distance without coupling correctionAnd velocityEstimated value of (a):
(6.3) obtaining the unambiguous speed estimation of the target by using a multi-frequency or multi-carrier equal speed ambiguity resolution method
(6.4) utilization ofDecoupling correction is carried out on the distance to obtain the final distance estimation
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010289645.7A CN111505618B (en) | 2020-04-14 | 2020-04-14 | Decoupling correction ranging method based on frequency estimation and suitable for field of vehicle-mounted millimeter wave radar |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010289645.7A CN111505618B (en) | 2020-04-14 | 2020-04-14 | Decoupling correction ranging method based on frequency estimation and suitable for field of vehicle-mounted millimeter wave radar |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111505618A true CN111505618A (en) | 2020-08-07 |
CN111505618B CN111505618B (en) | 2022-06-24 |
Family
ID=71867676
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202010289645.7A Active CN111505618B (en) | 2020-04-14 | 2020-04-14 | Decoupling correction ranging method based on frequency estimation and suitable for field of vehicle-mounted millimeter wave radar |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN111505618B (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112415479A (en) * | 2020-11-02 | 2021-02-26 | 扬州船用电子仪器研究所(中国船舶重工集团公司第七二三研究所) | Continuous wave navigation radar frequency spectrum pairing method based on frequency diversity technology |
CN112731081A (en) * | 2020-12-25 | 2021-04-30 | 国网山东省电力公司电力科学研究院 | Method and device for acquiring partial discharge phase |
CN113189577A (en) * | 2021-04-13 | 2021-07-30 | 电子科技大学 | LFMCW vehicle-mounted radar distance and speed measurement method based on rapid slope mode |
WO2022174392A1 (en) * | 2021-02-19 | 2022-08-25 | 华为技术有限公司 | Positioning method and apparatus |
CN115015942A (en) * | 2022-08-09 | 2022-09-06 | 中国人民解放军军事科学院国防科技创新研究院 | Self-adaptive underwater target acoustic speed measurement device and method |
EP4198552A1 (en) * | 2021-12-20 | 2023-06-21 | Aptiv Technologies Limited | Movement compensation for multi-dimensional radar signal processing |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105738889A (en) * | 2016-02-23 | 2016-07-06 | 华域汽车系统股份有限公司 | Frequency modulated continuous wave speed measurement and distance measurement method |
CN106405541A (en) * | 2016-11-14 | 2017-02-15 | 苏州途视电子科技有限公司 | Fully-coherent continuous-wave Doppler radar and distance measurement and velocity measurement method thereof |
CN107861117A (en) * | 2017-10-17 | 2018-03-30 | 电子科技大学 | A kind of multiple target measurement method of parameters suitable for continuous wave perimeter surveillance radar |
CN109471095A (en) * | 2018-11-06 | 2019-03-15 | 哈尔滨工程大学 | Fmcw radar distance estimating algorithm based on iteratively faster interpolation |
-
2020
- 2020-04-14 CN CN202010289645.7A patent/CN111505618B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105738889A (en) * | 2016-02-23 | 2016-07-06 | 华域汽车系统股份有限公司 | Frequency modulated continuous wave speed measurement and distance measurement method |
CN106405541A (en) * | 2016-11-14 | 2017-02-15 | 苏州途视电子科技有限公司 | Fully-coherent continuous-wave Doppler radar and distance measurement and velocity measurement method thereof |
CN107861117A (en) * | 2017-10-17 | 2018-03-30 | 电子科技大学 | A kind of multiple target measurement method of parameters suitable for continuous wave perimeter surveillance radar |
CN109471095A (en) * | 2018-11-06 | 2019-03-15 | 哈尔滨工程大学 | Fmcw radar distance estimating algorithm based on iteratively faster interpolation |
Non-Patent Citations (4)
Title |
---|
GAO JINGKUN等: "RANGE-AZIMUTH SAR IMAGING BASED ON BAYESIAN COMPRESSIVE SENSING", 《 2014 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING (ICSP)》 * |
YANG LI等: "An Improved Algorithm for Doppler Ambiguity Resolution Using Multiple Pulse Repetition Frequencies", 《2017 9TH INTERNATIONAL CONFERENCE ON WIRELESS COMMUNICATIONS AND SIGNAL PROCESSING (WCSP)》 * |
严鑫: "毫米波雷达多目标检测与参数估计算法研究", 《中国优秀博硕士学位论文全文数据库(硕士) 信息科技辑》 * |
侯志等: "一种对称三角线性调频连续波雷达的校正算法", 《兵工学报》 * |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112415479A (en) * | 2020-11-02 | 2021-02-26 | 扬州船用电子仪器研究所(中国船舶重工集团公司第七二三研究所) | Continuous wave navigation radar frequency spectrum pairing method based on frequency diversity technology |
CN112415479B (en) * | 2020-11-02 | 2023-06-30 | 扬州船用电子仪器研究所(中国船舶重工集团公司第七二三研究所) | Frequency diversity technology-based continuous wave navigation radar spectrum pairing method |
CN112731081A (en) * | 2020-12-25 | 2021-04-30 | 国网山东省电力公司电力科学研究院 | Method and device for acquiring partial discharge phase |
WO2022174392A1 (en) * | 2021-02-19 | 2022-08-25 | 华为技术有限公司 | Positioning method and apparatus |
CN113189577A (en) * | 2021-04-13 | 2021-07-30 | 电子科技大学 | LFMCW vehicle-mounted radar distance and speed measurement method based on rapid slope mode |
EP4198552A1 (en) * | 2021-12-20 | 2023-06-21 | Aptiv Technologies Limited | Movement compensation for multi-dimensional radar signal processing |
CN115015942A (en) * | 2022-08-09 | 2022-09-06 | 中国人民解放军军事科学院国防科技创新研究院 | Self-adaptive underwater target acoustic speed measurement device and method |
CN115015942B (en) * | 2022-08-09 | 2022-11-01 | 中国人民解放军军事科学院国防科技创新研究院 | Self-adaptive underwater target acoustic speed measurement device and method |
Also Published As
Publication number | Publication date |
---|---|
CN111505618B (en) | 2022-06-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN111505618B (en) | Decoupling correction ranging method based on frequency estimation and suitable for field of vehicle-mounted millimeter wave radar | |
CN111537966B (en) | Array antenna error correction method suitable for millimeter wave vehicle-mounted radar field | |
CN110579763B (en) | Resolving doppler ambiguity in radar using digital multipulse repetition frequencies | |
CN107861117B (en) | Multi-target parameter measuring method suitable for continuous wave perimeter surveillance radar | |
CN107561508B (en) | Coherent accumulation detection method for uniformly accelerated moving target | |
CN101825707B (en) | Monopulse angular measurement method based on Keystone transformation and coherent integration | |
CN107843892B (en) | High-speed target Doppler velocity measurement method based on least square method | |
CN108490443B (en) | Multi-subarray synthetic aperture sonar omega-k imaging algorithm based on analytic solution and NUFFT | |
CN112526474B (en) | FMCW radar range-velocity joint estimation method based on full-phase Fourier transform | |
CN110161472B (en) | Broadband vehicle-mounted millimeter wave radar speed ambiguity resolution method based on signal multiplexing | |
CN107132534B (en) | Optimization method for high-speed radar target frequency domain detection | |
CN110297233B (en) | LFMCW array radar signal parallel pipelining processing method | |
CN110431436B (en) | Method for determining the radial relative acceleration of at least one object and radar device | |
CN110907910A (en) | Distributed coherent radar moving target echo coherent synthesis method | |
CN111273248B (en) | Speed ambiguity solving method based on phase compensation | |
CN109946659B (en) | Vehicle-mounted millimeter wave radar linear frequency modulation continuous wave motion frequency expansion correction method | |
CN110286370B (en) | Motion compensation method for shipborne ground wave radar in sailing state | |
CN113093120B (en) | Method for estimating PRI agile radar target parameters based on capon algorithm | |
CN109613507B (en) | Detection method for high-order maneuvering target radar echo | |
CN115508820A (en) | Target detection method of linear frequency modulation pulse radar | |
CN110058226B (en) | Phased array radar angle measurement system based on positive and negative frequency modulation slope linear frequency modulation | |
CN113534125B (en) | Method for estimating target fuzzy speed | |
CN109581350B (en) | Radar distance and speed measurement method and device based on time-frequency integral interpolation | |
CN115494485A (en) | Two-dimensional low-sidelobe constant-resolution forward-looking sonar imaging method and system | |
CN115421134A (en) | Method and device for resolving ambiguity of radar speed and millimeter wave radar |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |