LU504229B1 - Ambiguity and eclipse solving method for radar based on orthogonal frequency division multiplexing signal - Google Patents

Ambiguity and eclipse solving method for radar based on orthogonal frequency division multiplexing signal Download PDF

Info

Publication number
LU504229B1
LU504229B1 LU504229A LU504229A LU504229B1 LU 504229 B1 LU504229 B1 LU 504229B1 LU 504229 A LU504229 A LU 504229A LU 504229 A LU504229 A LU 504229A LU 504229 B1 LU504229 B1 LU 504229B1
Authority
LU
Luxembourg
Prior art keywords
pulse
radar
signal
echo
transmitting
Prior art date
Application number
LU504229A
Other languages
French (fr)
Inventor
Jihong Yan
Original Assignee
Yangtze Delta Region Institute Quzhou Univ Of Electronic Science And Technology Of China
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Yangtze Delta Region Institute Quzhou Univ Of Electronic Science And Technology Of China filed Critical Yangtze Delta Region Institute Quzhou Univ Of Electronic Science And Technology Of China
Application granted granted Critical
Publication of LU504229B1 publication Critical patent/LU504229B1/en

Links

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
    • 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
    • G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
    • G01S13/12—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the pulse-recurrence frequency is varied to provide a desired time relationship between the transmission of a pulse and the receipt of the echo of a preceding pulse
    • 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
    • G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
    • G01S13/26—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
    • G01S13/28—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the transmitted pulses use a frequency- or phase-modulated carrier wave with time compression of received pulses
    • 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
    • G01S13/581—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets
    • G01S13/582—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of interrupted pulse 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
    • G01S13/02—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
    • 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
    • G01S7/28—Details of pulse systems
    • 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
    • G01S13/347—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 using more than one modulation frequency

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

An ambiguity and eclipse solving method for a radar based on an orthogonal frequency division multiplexing signal relates to the radar field. The method includes the steps of: confirming a number of an orthogonal LFM (Linear Frequency Modulation) pulse signal, transmitted by adopting a high repetition frequency mode, in a time corresponding to a maximum detection range, based on a maximum duration corresponding to a farthest detection range of the radar, and the PRI (Pulse Recurrence Interval), performing frequency domain pulse compression processing on an obtained echo matrix R in combination with a transmitting pulse LFM signal, so as to obtain a processed new matrix, and performing MTD (Moving Target Detection) treatment on the processed new matrix. At the same time, the method solves the problems of range eclipse, range ambiguity and velocity ambiguity.

Description

BL-5683
AMBIGUITY AND ECLIPSE SOLVING METHOD FOR RADAR BASED ON LUS04229
ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SIGNAL
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Chinese patent application No. 202111081641.0, filed to the China National Intellectual Property Administration on September 15, 2021 and entitled "Ambiguity and Eclipse Solving Method for Radar based on Orthogonal Frequency
Division Multiplexing Signal", the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to the radar field, in particular to an ambiguity and eclipse solving method for a radar based on an orthogonal frequency division multiplexing signal.
BACKGROUND
[0003] With numerous advantages, a digital array radar has become the mainstream in the radar field. There is no prior information in a search stage of the digital array radar, and a target range, a velocity, an angle and other information are unknown, a PD (Pulse Doppler) radar system is commonly used, in order to detect a distant target. An antenna 1s shared for transmitting and receiving (or the antenna is not shared for transmitting and receiving, and this patent aims at the scenario that the antenna is shared for transmitting and receiving), the transmitting and receiving states are mutually switched, and the transmitting leakage will not affect to receive a target echo.
[0004] When a delay time of the target echo is greater than a repetition cycle of a transmitting pulse, the radar in a pulse system will generate a range ambiguity. When a
Doppler frequency, caused by the movement of the target, is greater than a half of a repetition frequency of the transmitting pulse, a velocity ambiguity will generate.
[0005] In order to solve the problem of the velocity ambiguity, a working mode of HPRF (High Pulse Repetition Frequency) may be adopted, which also bring the problems of range ambiguity and range eclipse at the same time. In order to solve the problem of the range ambiguity, the traditional method is to adopt several different PRIs (Pulse Recurrence
Interval), the PRI is usually selected according to a remainder theorem, a one-dimensional set algorithm, a table look-up method and the like, but the above methods have their 1
BL-5683 respective shortages. LU504229
SUMMARY
[0006] The technical problem to be solved by the present disclosure is: range ambiguity and eclipse, and velocity ambiguity. The present disclosure provides an ambiguity and eclipse solving method for a radar based on an orthogonal frequency division multiplexing signal, in order to solve the above problem.
[0007] A traditional radar signal method is that an echo between two pulses is subjected to pulse compression processing, therefore the problem of the range ambiguity will be caused.
[0008] The present disclosure is achieved by the following technical solution:
[0009] Step 1: confirming a time width for transmitting an LFM (Linear Frequency
Modulation) pulse based on a range blind zone and a range resolution of a radar system, to ensure that a target echo signal being not overlapped with a transmitting pulse;
[0010] confirming a minimum transmitted PRF (Pulse Repetition Frequency) adopted in a radar cycle based on a maximum radial velocity of a target, to ensure not to generate a velocity ambiguity;
[0011] Step 2: confirming a number of an orthogonal LFM pulse signal, transmitted by adopting a high repetition frequency mode, in the time corresponding to the maximum detection range, based on a maximum duration corresponding to a farthest detection range of the radar, and the PRI, where adopting the high repetition frequency mode is to avoid the velocity ambiguity occurred to the radar;
[0012] The orthogonal LFM pulse signal is an orthogonal LFM signal with excellent self- correlation and cross-correlation properties;
[0013] That is, a plurality of orthogonal LFM transmitting signals are ai, as,..., am, the transmitting signals are mutually orthogonal, and various pulses meet
[0014] fa,0)-a;()dt = G We 7
[0015] In the formula, E indicates a signal energy;
[0016] A reciprocal of the PRF is transmitted, PRI is a time interval of two adjacent transmitting pulses, the number (that is, m pulse signals: ai, az, ...am) of the transmitted orthogonal LFM pulse signal is confirmed in the time Tmax corresponding to the maximum detection range, and these LFM pulse signals are pairwise orthogonal, with excellent self- correlation and cross-correlation properties (that is, lower self-correlation sidelobes, and lower cross-correlation peak value); 2
BL-5683
T LU504229
[0017] m= PRI
[0018] Step 3: Several orthogonal LFM pulse signals are transmitted and the echo signals are accumulated by radar system during a radar cycle CPI (Coherent Processing Interval);
[0019] Further, one radar cycle CPI in Step 3 includes a number of the time Tmax corresponding to the maximum detection range, and adaptive selection is carried out based on an application scenario of the target.
[0020] In Step 3, further including a pre-treatment process for the echo signal, and the pre- treatment process is that the echo signal, collected by a receiver of the radar system in Tmax, is down converted to a digital baseband signal;
[0021] In the present disclosure, a switching system for transmitting and receiving is adopted for the radar system, the echo collected by the receiver in Tmax includes the echo among a plurality of pulses, the transmitting pulse in Tmax is partially reset to zero, a time sequence is reconstructed, and the sequence includes m null sequences, equal to the transmitting pulses, and m echo sequences in Tmax.
[0022] In an echo matrix R constructed by the above method, the time span in the first line is Tmax (the transmitting time of the a; signal is the started duration), and the time span in the second line is also Tmax (the transmitting time of the a, signal is the started duration), and so on for the subsequent lines.
[0023] If one radar cycle CPI includes a plurality of Tmax, the subsequent echo in the CPI is also processed similarly, to obtain the echo matrix R, as shown in the following formula.
R Out: Fans 002s Tazo, Om To ; a 024) #5 [5
R, Ons Tom» DaF art > Oam >" amy
[0025] Step 4: performing the frequency domain pulse compression treatment on the echo matrix R in combination with the transmitting pulse LFM signal to obtain a processed new matrix after obtaining the echo matrix R constructed in step 3, and performing MTD (Moving Target Detection) treatment on the processed new matrix;
[0026] The detail treatment method of the frequency domain pulse compression is as follows:
[0027] The echo Ri in the first line of the echo matrix R is subjected to frequency domain pulse compression with A1, A1 is reset to zero after transmitting the pulse LFM signal ai, to obtain Aj and Rı in an equal time sequence, and A; and R; are substituted into the following 3
BL-5683 formula for treatment. LU504229
[0028] X, = IFFT(FFT(R,) - CONJ(FFT(4,)))
[0029] In the formula, CONJ is a conjugate operation;
[0030] The echo R; in the second line of the echo matrix R is subjected to frequency domain pulse compression with Az, A» is reset to zero after transmitting the pulse LFM signal az, to obtain A» and R> in an equal time sequence;
[0031] Each line of the echo matrix R is subjected to the above treatment, the processed data is put in the corresponding line of the processed new matrix X, each row of the processed new matrix X is subjected to FFT (Fast Fourier Transform), that is, MTD treatment, and a peak value in the matrix is used to indicate the distance and velocity of the target.
[0032] In the traditional PD radar, different pulses will be overlapped with the echoes with different ranges and targets, and the peak value of the MTD result of the traditional method is in range ambiguity, which is not enough to distinguish different targets from the overlapped echoes. After the above treatment, even the echoes are overlapped with a plurality of target echoes, and the peak value in the MTD result may reflect that different targets are at different ranges, thus the problem of the range ambiguity of the echo overlapping is solved.
[0033] The radar usually adopts the switching mode for transmitting and receiving, and it’s hard to avoid the problem of range eclipse. In order to avoid range eclipse caused by switching for transmitting and receiving, the transmitting signal may adopt another pulse repetition frequency in some radar cycles, the repetition frequency is slightly greater than the minimum pulse repetition frequency, and at this time, the orthogonal LFM pulse signals are pairwise orthogonal (such as, bi, b2,...,bn in FIG. 1, and these orthogonal LFM pulse signals are pairwise orthogonal and have excellent self-correlation and cross-correlation properties, and n is slightly greater than m). The problem of the range eclipse is solved by transmitting the repetition frequency of two different pulses and processing the subsequent radar signal.
[0034] The present disclosure has the following advantages and beneficial effects:
[0035] At the same time, the present disclosure solves the problems of range eclipse, range ambiguity and velocity ambiguity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The drawings illustrated herein are used to provide a further understanding of embodiments of the present disclosure, and constitute a part of this application, but do not 4
BL-5683 constitute limitations to the embodiments of the present disclosure. In the drawings: LUS04229
[0037] FIG. 1 is a schematic diagram of an orthogonal LFM pulse signal, transmitted in a radar cycle, of the present disclosure;
[0038] FIG. 2 is a MTD diagram of a pulse signal with same LFM and transmitted by a traditional PD radar;
[0039] FIG. 3 is a MTD diagram of an orthogonal LFM pulse signal, transmitted in the present disclosure.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0040] In the text below, terms “comprise” or “may comprise” used in various embodiments of the present disclosure indicates a function of the present disclosure, an operation or existence of a component, and does not limit the addition of one or more functions, the operation and the component. In addition, terms “comprise”, “have” and their cognate words used in various embodiments of the present disclosure are merely intended to indicate a specific characteristic, a figure, a step, an operation, a component, an assembly or a combination of the above items, and shall not be understood as the existence of firstly eliminating one ore more other characteristics, the figure, the step, the operation, the component, the assembly or the combination of the above items or a possibility of adding one or more other characteristics, the figure, the step, the operation, the component, the assembly or the combination of the above items.
[0041] In various embodiments of the present disclosure, the expression “or” or “at least one A or/and B” includes any combination or all combinations of characters listed at the same time. For example, the expression “A or B” or “at least one of A or/and B” may include
A, B or A and B.
[0042] The expressions (such as “first”, “second” and the like) used in various embodiments of the present disclosure may modify various components in various embodiments, instead of limiting the corresponding components. For example, the above expressions are not intended to limit the sequence and/or significance of the above components. The above expressions are merely used for the purpose of distinguishing one component from other components. For example, a first user device and a second user device are configured to indicate different user devices, although both are user devices. For example, without deviating from the scope of various embodiments of the present disclosure, the first component can be called as the second component, and similarly, the second component can also be called as the first component.
BL-5683
[0043] It is noted that if one constituent component is “connected” to another constituent ~~ LU504229 component in the description, the first constituent component is directly connected to the second constituent component, and a third constituent component is “connected” between the first constituent component and the second constituent component. On the contrary, when one constituent component is “directly connected” to another constituent component, it is understood that the third constituent component does not exist between the first constituent component and the second constituent component.
[0044] Terms used in various embodiments of the present disclosure are only for the purpose of describing specific embodiments and not intended to limit various embodiments of the present disclosure. As used herein, singular forms are also intended to include the plural forms, unless otherwise specified in the context. Unless otherwise defined, all terms (including technical terms and scientific terms) used here have the same meaning as the general understanding of those of ordinary skill in the art. The terms (such as terms defined in commonly used dictionaries) will be explained as the meaning that is the same as that in the context of the related technical art, and not explained as the idealized meaning or the formal meaning, unless itis clearly defined in various embodiments of the present disclosure.
[0045] In order to enable the purpose, the technical solution and the advantage of the present disclosure to be more clear, the present disclosure is further described in detail below in combination with the embodiments and the drawings. The exemplary embodiments of the present disclosure and the description thereof are used to explain the present disclosure, but do not constitute improper limitations to the present disclosure.
[0046] A LFM signal is a pulse compression radar signal that is widely used. In the present disclosure, the width of the transmitting pulse is reduced as far as possible in order to reduce the working blind zone of the LFM pulse radar, that is, a chip length of the LFM signal. In order to solve the problem of the velocity ambiguity, a working mode of HPRF is adopted, and the problem of the range ambiguity can be solved by adopting the processing method for the received signal in the present disclosure.
[0047] The specific embodiment is as follows:
[0048] A sampling frequency of the PD radar receiver is 100 MHz, the bandwidth B of the single LFM pulse signal is 10 MHz (the frequencies of the four LFM pulse signals are 0-10
MHz, 10-20 MHz, 20-30 MHz, and 30-40 MHz), the pulse width t is 1.28 us, the PRI is 64 us, Tmax includes four PRIs, one CPI includes 16 Tmax, the radio frequency fis 3 GHz, and ¢ is velocity of light. At this time, the range resolution is 6
BL-5683 € LU504229
[0049] ©. = 25 =15m
[0050] The range blind zone is
[0051] R, = PA =192m
[0052] The maximum unambiguous range is
[0053] R_ = a = 38400m
[0054] The maximum unambiguous velocity 1s
[0055] v, = TTR =390.625m/ s
[0056] The range of the target is set as 20 Km, the target speed is 270 m/s, and the signal- to-noise ratio is set to -15 dB. If the transmitting signals adopt the same signals, the MTD results are as shown in FIG. 2, and at this time, the echo, from which transmitting pulse signal, cannot be distinguished, and then the range ambiguity occurs.
[0057] The LFM pulse signals, mutually orthogonal, are transmitted by adopting the method of the present disclosure, as shown in FIG. 1, the MTD result is as shown in FIG.3, the target range and the velocity can be accurately measured, only one peak value is in FIG. 3, that is, the problem of the range ambiguity does not exist.
[0058] In order to avoid the range eclipse caused by the switching of transmitting and receiving (the target echo of the current transmitting pulse signal delays and is overlapped with the next transmitting pulse, the echo signal is not received and processed, so the target information is not obtained), and another pulse repetition frequency is adopted in this embodiment, and one radar cycle Tmax includes 5 PRIs. The problem of the range eclipse is solved by transmitting the repetition frequency of two different pulses and processing the subsequent radar signal.
[0059] The purpose, the technical solution and the beneficial effects of the present disclosure are further described in detail through the specific implementation modes above.
It should be understood that the above is only optional embodiments of the present disclosure and not intended to limit the protective scope of the present disclosure. Any modifications, equivalent replacements, improvements and the like made within the spirit and principle of the present disclosure shall fall within the protective scope of the present disclosure. 7

Claims (6)

BL-5683 CLAIMS LU504229
1. An ambiguity and eclipse solving method for a radar based on an orthogonal frequency division multiplexing signal, comprising the following steps of: step 1: confirming a time width for transmitting an LFM (Linear Frequency Modulation) pulse based on a range blind zone and a range resolution of a radar system; confirming a minimum transmitted PRF (Pulse Repetition Frequency) adopted in a radar cycle based on a maximum radial velocity of a target; step 2: confirming a number of an orthogonal LFM pulse signal, transmitted by adopting a high repetition frequency mode, in a time corresponding to a maximum detection range, based on a maximum duration corresponding to a farthest detection range of the radar, and the PRI; step 3: several orthogonal LFM pulse signals are transmitted and the echo signals are accumulated by radar system during a radar cycle CPI (Coherent Processing Interval), step 4: obtaining an echo matrix R obtained in step 3, performing a frequency domain pulse compression treatment on the echo matrix R in combination with the transmitting pulse LFM signal to obtain a processed new matrix, and performing MTD (Moving Target Detection) treatment on the processed new matrix.
2. The ambiguity and eclipse solving method for the radar based on the orthogonal frequency division multiplexing signal according to claim 1, wherein the orthogonal LFM pulse signal is an orthogonal LFM signal with excellent self-correlation and cross-correlation properties; that is, a plurality of orthogonal LFM transmitting signals are ai, az,..., am, the transmitting signals are mutually orthogonal, and various pulses meet fa.) (0dr = ol: / and in the formula, E indicates a signal energy, and m the number of the transmitting signal.
3. The ambiguity and eclipse solving method for the radar based on the orthogonal frequency division multiplexing signal according to claim 2, wherein one radar cycle CPI in step 3 comprises a number of the time Tmax corresponding to the maximum detection range, and adaptive selection is carried out based on an application scenario of a target. 8
BL-5683
4. The ambiguity and eclipse solving method for the radar based on the orthogonal 7504229 frequency division multiplexing signal according to claim 3, in step 3, further comprising a pre-treatment process for the echo signal, and the pre-treatment process is that the echo signal, collected by a receiver of the radar system in Tmax, 1s down converted to a digital baseband signal; the echo collected by the receiver within Tmax comprises the echo among a plurality of pulses, the transmitting pulse in Tmax is partially reset to zero, a time sequence is reconstructed, and the sequence comprises m null sequences, equal to the transmitting pulses, and m echo sequences in Tmax.
5. The ambiguity and eclipse solving method for the radar based on the orthogonal frequency division multiplexing signal according to claim 4, wherein in the step 4, a detail processing method for the frequency domain pulse compression is as follows: the echo Rı in the first line of the echo matrix R is subjected to frequency domain pulse compression with A1, A1 is reset to zero after transmitting the pulse LFM signal a, to obtain A1 and Ry in an equal time sequence, and A; and Rı are substituted into the following formula for treatment X, = IFFT(FFT(R,) - CONJ(FFT(4,))) in the formula, CONJ is a conjugate operation; the echo R> in the second line of the echo matrix R is subjected to frequency domain pulse compression with Az, A; is reset to zero after transmitting the pulse LFM signal az, to obtain A» and R> in an equal time sequence; and each line of the echo matrix R is subjected to the above treatment, the processed data is put in the corresponding line of the processed new matrix X, each row of the processed new matrix X is subjected to FFT (Fast Fourier Transform), that is, MTD treatment, and a peak value in the matrix is used to indicate the range and velocity of the target.
6. The ambiguity and eclipse solving method for the radar based on the orthogonal frequency division multiplexing signal according to any one of claims 1-5, wherein the radar system adopts a switching mode for transmitting and receiving, and in a partial radar cycle, the transmitting signal adopts another pulse repetition frequency, which is slightly greater than the minimum pulse repetition frequency. 9
LU504229A 2021-09-15 2022-09-14 Ambiguity and eclipse solving method for radar based on orthogonal frequency division multiplexing signal LU504229B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111081641.0A CN113791404B (en) 2021-09-15 2021-09-15 Radar defuzzification and shielding method based on orthogonal frequency division signals

Publications (1)

Publication Number Publication Date
LU504229B1 true LU504229B1 (en) 2023-07-17

Family

ID=78878482

Family Applications (1)

Application Number Title Priority Date Filing Date
LU504229A LU504229B1 (en) 2021-09-15 2022-09-14 Ambiguity and eclipse solving method for radar based on orthogonal frequency division multiplexing signal

Country Status (3)

Country Link
CN (1) CN113791404B (en)
LU (1) LU504229B1 (en)
WO (1) WO2023040858A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113791404B (en) * 2021-09-15 2024-05-07 电子科技大学长三角研究院(衢州) Radar defuzzification and shielding method based on orthogonal frequency division signals
CN115356717B (en) * 2022-10-19 2023-03-24 艾索信息股份有限公司 Distance occlusion solving target detection method and device, computer equipment and medium
CN116755073B (en) * 2023-06-21 2024-03-26 上海雷骥电子科技有限公司 Method for resolving distance ambiguity by using lookup table and application
CN116541696B (en) * 2023-07-07 2023-09-19 北京理工大学 Pulse system fuze echo signal-to-noise ratio estimation method
CN118112517B (en) * 2024-04-25 2024-07-09 广东工业大学 Combined radar communication waveform signal construction method and combined radar communication system

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101470202B (en) * 2007-12-26 2012-05-23 清华大学 Pulse Doppler radar system and its signal processing method
CN102759733A (en) * 2011-04-27 2012-10-31 电子科技大学 Speed measuring pulse radar and speed measuring method of same
CN109164422A (en) * 2018-09-26 2019-01-08 西安电子科技大学 A kind of PD Radar Ambiguity Resolution distance measuring method based on shake repetition
DE102018221085A1 (en) * 2018-12-06 2020-06-10 Robert Bosch Gmbh Ambiguity resolution for MIMO radar system
CN109814073B (en) * 2019-01-21 2022-11-11 西安电子科技大学 Method for resolving fuzzy speed measurement by MTD radar
CN109884632A (en) * 2019-02-21 2019-06-14 中国科学院电子学研究所 A kind of inhibition range ambiguity method, apparatus and computer readable storage medium
CN113050077B (en) * 2021-03-18 2022-07-01 电子科技大学长三角研究院(衢州) MIMO radar waveform optimization method based on iterative optimization network
CN113791404B (en) * 2021-09-15 2024-05-07 电子科技大学长三角研究院(衢州) Radar defuzzification and shielding method based on orthogonal frequency division signals

Also Published As

Publication number Publication date
CN113791404B (en) 2024-05-07
WO2023040858A1 (en) 2023-03-23
CN113791404A (en) 2021-12-14

Similar Documents

Publication Publication Date Title
LU504229B1 (en) Ambiguity and eclipse solving method for radar based on orthogonal frequency division multiplexing signal
De Wit et al. Orthogonal waveforms for FMCW MIMO radar
Lellouch et al. OFDM waveforms for frequency agility and opportunities for Doppler processing in radar
CN110837081A (en) High-speed target detection method based on P/D band radar signal fusion processing
CN110988864B (en) MTI radar speed measuring method with frequency agility
US20240176005A1 (en) Method for solving radar ambiguity and occlusion based on orthogonal two-phase coded signal
WO2020162751A1 (en) Phase coded frequency modulated continuous wave radar system
Engler Technical issues in ultra-wideband radar systems
CN103048695A (en) Detecting device based on combined barker code burst pulses
Gao et al. Performance analysis and experimental study on distributed aperture coherence-synthetic radar
US7755538B2 (en) Radar apparatus
Lellouch et al. Processing alternatives in OFDM radar
Zhao et al. Coherent process and optimal weighting for sparse frequency agility waveform
CN117434534A (en) Multichannel SAR imaging near-field test system based on board card vector network
Yan et al. An unambiguity method for PD radar using orthogonal binary phase coded signal
Dash et al. Generalized OFDM-LFM waveform design and analysis for multistatic airborne radar
Rodriguez et al. Experimental evaluation of Supervised Reciprocal Filter Strategies for OFDM-radar signal processing
Yan et al. An Unambiguity and Anti-Range Eclipse Method for PD Radar Using Biphase Coded Signals
Li et al. Simulation and implementation of spectrum synthesis method for linear modulated stepped frequency signal based on spectral extraction
US20230176188A1 (en) Target tracking using circulated time division multiplexing of multiple-input multiple-output radar
Huang et al. Multi-target detection for FMCW radar based on interferometer direction finding
CN104965201A (en) Radar velocity measurement technology
Yan et al. An unambiguity Method for PD Radar using OFDM-LFM Signal
Hong et al. Velocity Estimation Algorithm Based on Staggered Subband Groups for DDMA-MIMO Radar
CN115356691B (en) Multi-target distance speed coupling solving method based on single-group SFCW radar signals

Legal Events

Date Code Title Description
FG Patent granted

Effective date: 20230717