CN113820667A - Transmitting end beam forming method based on time diversity array - Google Patents

Transmitting end beam forming method based on time diversity array Download PDF

Info

Publication number
CN113820667A
CN113820667A CN202110952469.5A CN202110952469A CN113820667A CN 113820667 A CN113820667 A CN 113820667A CN 202110952469 A CN202110952469 A CN 202110952469A CN 113820667 A CN113820667 A CN 113820667A
Authority
CN
China
Prior art keywords
transmitting
distance
time
tda
radar
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.)
Pending
Application number
CN202110952469.5A
Other languages
Chinese (zh)
Inventor
朱圣棋
余昆
李西敏
刘永军
兰岚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xidian University
Original Assignee
Xidian University
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 Xidian University filed Critical Xidian University
Priority to CN202110952469.5A priority Critical patent/CN113820667A/en
Publication of CN113820667A publication Critical patent/CN113820667A/en
Pending legal-status Critical Current

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
    • 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
    • G01S7/282—Transmitters
    • 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
    • G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Landscapes

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

Abstract

The invention belongs to the technical field of signal processing and discloses a transmitting end beam forming method based on a time diversity array. The invention provides a space-time two-dimensional matched filtering method based on angle search in a TDA radar, which is used for forming a transmitting end wave beam. And the antenna directional diagram coupled by the distance angle is utilized, so that the effective utilization of the system airspace degree of freedom is realized. Through angle search, equivalent to beam forming at a transmitting end, distance dimension matching filtering is carried out at the same time, and distance information of a target is obtained. The invention can realize flexible control of the wave beam of the transmitting end at the receiving end, has simple waveform and is easy to realize engineering.

Description

Transmitting end beam forming method based on time diversity array
Technical Field
The invention belongs to the technical field of signal processing, and particularly relates to a transmitting end beam forming method based on a time diversity array. The method can be used for estimating target angle parameters at a transmitting end and obtaining the ultra-low side lobe antenna directional diagram through combined receiving end beam forming.
Background
The array signal processing is widely applied to the fields of radar, sonar, wireless communication and astronomy, and has important military and civil values. The traditional phased array antenna realizes beam scanning by changing the phase of the feed unit, needs a large number of phase shifters to realize beam scanning, and occupies large system overhead. On the other hand, the disadvantage of the transmit beam forming of the phased array antenna is that in order to obtain stronger signal echoes, beam scanning needs to be performed in a time-sharing manner, and the transmit beam is not controllable at the receiving end. With the proposed MIMO (Multiple In Multiple Out, MIMO) technology, equivalent transmit beamforming can be performed at the receiving end, but the implementation difficulty of the ideal waveform engineering close to orthogonal is large. Frequency Diversity Array (FDA), a new array that achieves spatial beam scanning without phase shifters, introduces additional phase differences by changing the Frequency increment between elements, and the beam pointing direction varies with distance. For the distance-dependent study that the FDA mainly prefers to be based on the separation of the transmitted signals, there is also a problem that orthogonal waveforms are difficult to design.
In recent years, new requirements on beams in the field of radar detection are provided, and flexible and controllable emission beams of the array antenna are expected. The MIMO radar utilizes orthogonal waveforms formed between transmitting array elements, and realizes the separation of transmitting waveforms by a method of receiving matched filtering, thereby obtaining the degree of freedom of a transmitting end. The FDA utilizes the difference of carrier frequencies among array elements to obtain a directional diagram coupled with a transmitting distance angle, and combines the MIMO technology to obtain the controllable degree of freedom of a distance dimension. Different from the FDA, a Time Diversity Array (TDA) introduces a tiny Time delay between each transmitting Array element, and research shows that its transmitting pattern also has distance-angle coupling characteristics, but its transmitting end freedom is not required to be combined with MIMO technology.
Disclosure of Invention
In view of the above existing problems, an object of the present invention is to provide a transmit-end beam forming method based on a time diversity array, which obtains spatial dimension Degrees of Freedom by using the difference in delay between array elements of different pulses, and is equivalent to performing beam forming at a transmit end by angle search, thereby achieving effective utilization of system Degrees of Freedom (Degrees of Freedom, DOF), and performing distance dimension matching filtering to obtain distance information of a target.
The technical principle of the invention is as follows: in a TDA radar, a space-time two-dimensional matching filtering method based on angle search is provided for forming a transmitting end wave beam. By using the antenna directional diagram coupled with the distance angle, the effective utilization of the system space domain degree of Freedom (DOF) is realized. Through angle search, equivalent to beam forming at a transmitting end, distance dimension matching filtering is carried out at the same time, and distance information of a target is obtained. And finally, providing a time, Doppler and angle three-dimensional fuzzy function to analyze radar detection performance and electromagnetic wave distribution characteristics of the time diversity array radar.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme.
The transmitting end beam forming method based on the time diversity array comprises the following steps:
step 1, establishing a TDA radar model, selecting a linear frequency modulation signal with a certain time bandwidth product as a transmitting signal, and obtaining a synthetic transmitting signal S of the TDA radar at a targetr(t, θ) and a reception signal Γ (θ, R);
the method comprises the following steps that signals transmitted between adjacent array elements of the TDA have time delay, t is time, theta is a target angle, and R is a target distance;
step 2, the receiving signal gamma (theta, R) of the TDA radar is subjected to distance compression processing to obtain a frequency domain echo signal S after distance compressioncomp(frθ); separating echo signals of m transmitting signals in a time domain to obtain phase differences of the m array element transmitting signals, and further obtain a guide vector of a transmitting end;
step 3, in time domain, through searching for emission angle thetapTraversing all the distance units, and compressing the distance between the time domain echo signal and the search angle thetapAnd carrying out autocorrelation processing on the corresponding transmitting signals to construct a time-angle combined two-dimensional transmitting waveform.
Further, the distance-compressed time domain echo signal and the search angle θpThe corresponding transmitting signal is subjected to autocorrelation processing, and the following steps can be replaced:
constructing a space-time two-dimensional matched filter in a distance frequency domain:
Hcomp′(fr，θp)＝[Sinv*(-t，θp)]fourier；
wherein, the [ alpha ], [ beta ] -a]fourierRepresenting a fourier transform operation; sinv(-t，θp) Is a distance compressed time domain echo signal (.)*Represents a complex conjugate operator;
frequency domain multiplication processing is adopted to replace convolution operation, and the distance compressed frequency domain echo signal Scomp(frTheta) and Hcomp′(fr，θp) And multiplying, and performing inverse Fourier transform on the product result to obtain an echo signal after distance time domain matched filtering, thereby finishing the formation of the transmitting beam.
Compared with the prior art, the invention has the beneficial effects that:
the sampling TDA radar breaks through the dependence of the traditional phased array on a phase shifter, the pointing direction of a space wave beam covers the space domain within the time range of transmitting pulses, the scanning of the wave beam is realized, the system freedom degree can be improved by utilizing the controllability of array element delay among different pulses, the performance of the radar on the effective coverage of the space domain is improved, the transmitting waveform is simple, and the engineering is easy to realize.
Compared with the traditional phased array radar, the method can realize flexible control of the wave beam of the transmitting end at the receiving end. Compared with the MIMO radar, the method transmits the LFM signal, has simple waveform and is easy to realize engineering.
Drawings
The invention is described in further detail below with reference to the figures and specific embodiments.
FIG. 1 is a schematic diagram of a time diversity array transmit array model employed in the present invention;
FIG. 2 is a time diversity array transmit pattern employed by the present invention;
FIG. 3 is a simulation diagram of target angle estimation based on transmitting end beam forming implemented by the method of the present invention;
FIG. 4 is a directional diagram of an ultra-low antenna side lobe implementation by the method of the present invention in conjunction with receive-side beamforming;
FIG. 5 shows a method of the present inventionA simulation graph of the method to the three-dimensional fuzzy function; wherein, (a) and (b) are fuzzy function graphs when mismatch difference delta theta between a target angle designed by a filter and an actual target angle estimation is 0 DEG and delta theta is 50 DEG in the method of the invention; (c) and (d) is the time delay tau-0, tau-T in the method of the inventionpA fuzzy function graph at/4; (e) (f) is the mismatch f between the Doppler shift of the filter design and the actual received echo Doppler shift in the method of the inventiond＝0、fdB/4 as a fuzzy function graph.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.
The invention provides a transmitting end beam forming method based on a time diversity array, which comprises the following steps:
step 1, establishing a TDA radar model, selecting a linear frequency modulation signal with a certain time bandwidth product as a transmitting signal, and obtaining a synthetic transmitting signal S of the TDA radar at a targetr(t, θ) and a reception signal Γ (θ, R);
wherein, the signals transmitted between adjacent array elements of the TDA have time delay.
In substep 1a, referring to fig. 1, it is assumed that the TDA radar has M transmitting array elements and N receiving array elements, and the transmitting signals between adjacent array elements have a small delay difference. Constructing M omnidirectional uniform linear arrays, taking a first transmitting antenna as a reference antenna, and expressing an mth transmitting signal as:
Figure BDA0003219040500000051
wherein, TpDenotes the pulse width, fcDenotes the carrier frequency, gamma-B/TpThe expression frequency modulation, B the bandwidth and delta t the time delay between array elements. rect (t) is a rectangular envelope, represented as:
Figure BDA0003219040500000052
sub-step 1b, the composite transmit signal of the M transmit antennas at the target (R, θ) can be expressed as:
Figure BDA0003219040500000053
where R is the target distance and θ is the target angle. dTThe array element spacing of the transmitting antenna and c the speed of light.
In sub-step 1c, the phase difference of the electromagnetic waves emitted by the array due to the different spatial distribution can be expressed as:
Figure BDA0003219040500000054
according to the above formula, in a time range of transmitting a pulse width, the weight of the transmitting end of the TDA radar is time-varying, which is equivalent to perform time-varying directional pattern modulation on the transmitting array antenna, and the transmitting beam points to different angles at different times, as shown in fig. 2, due to the continuity of the transmitting time, the transmitting dimension of the TDA radar has a distance-angle coupling relationship.
Sub-step 1d, the receive signal Γ (θ, R) of the TDA radar is represented as:
Figure BDA0003219040500000061
where λ represents the wavelength and θ represents the target azimuth.
Step 2, the receiving signal gamma (theta, R) of the TDA radar is subjected to distance compression processing to obtain a frequency domain echo signal S after distance compressioncomp(fr，θ)，frIs the range frequency; separating echo signals of m transmitting signals in a time domain to obtain phase differences of the m transmitting signals, and further obtaining a guide vector a (theta) of a transmitting end as [ phi ], [ phi ]1，φ2，…，φm]T。
And a substep 2a of performing a distance dimension Fourier transform on the reception signal Γ (θ, R) to obtain a distance frequency domain echo signal.
And a substep 2b, performing distance compression processing on the echo signal in the distance frequency domain, wherein the distance compression is to multiply the echo signal by a compensation function in the frequency domain. The compensation function can be expressed as:
Figure BDA0003219040500000062
the compensated frequency domain echo signal is represented as:
Figure BDA0003219040500000063
wherein A represents the amplitude of the echo signal, ar(fr) Representing a distance frequency domain window function;
substep 2c, for the compensated frequency domain echo signal Scomp(frAnd theta) performing inverse Fourier transform to obtain a time domain echo signal after distance compression:
Figure BDA0003219040500000064
wherein sinc represents a sine function.
As can be seen from the above expression, the time delay difference Δ t (m-1) of the echo generated by the mth transmitting array element on the time domain envelope, so that the echoes of the m transmitting signals can be separated on the time domain, and the phase difference of the m transmitting signals is obtained as follows:
Figure BDA0003219040500000071
due to the use of time delays between the transmit array elements, the transmit signals can be separated in the time domain. The array elements of the transmitting end of the traditional phased array radar have no time delay difference, and the transmitting waveforms cannot be separated, so that the controllable degree of freedom of the transmitting end is not provided.
The transmitting steering vector of the TDA radar can be expressed by the phase difference between transmitting array elements as follows:
a(θ)＝[φ1，φ2，...，φm]T。
step 3, in time domain, through searching for emission angle thetapTraversing all the distance units, and compressing the distance between the time domain echo signal and the search angle thetapAnd carrying out autocorrelation processing on the corresponding transmitting signals to construct a time-angle combined two-dimensional transmitting waveform.
In an embodiment of the invention, the structure of the traditional phased array distance matching filter is independent of the angle, and the transmitting waveform of the TDA radar is dependent on the angle, so that the TDA radar matching filtering method based on angle search can be constructed. According to the idea of carrying out autocorrelation processing on the matched filtering echo signal and the transmitting waveform, the transmitting angle theta is searched in the time domainpTraversing all the distance units to construct a time-angle combined transmitting waveform;
the time domain echo signal after the TDA radar distance compression and the search angle thetapAnd carrying out autocorrelation processing on the corresponding transmitting signals to obtain echo signals after matched filtering:
Figure BDA0003219040500000072
wherein, thetaPIs the search angle.
It should be noted that, by the angle search method and the equivalent transmit beam forming, a transmit antenna pattern can be formed, and the target angle parameter estimation is realized.
In another embodiment of the present invention, in consideration of the large operation amount of the autocorrelation process, a space-time two-dimensional matched filter is constructed in the distance frequency domain:
Hcomp′(fr，θp)＝[Sinv *(-t，θp)]fourier，
wherein, the [ alpha ], [ beta ] -a]fourierRepresenting a Fourier transform operation, Sinv *(-t，θp) And constructing a time domain matched filter function based on angle search according to the echo signals after the distance compression.
Frequency domain multiplication processing is used to replace convolution operation to reduce the operation amount of the algorithm, and S is usedcomp(frTheta) and Hcomp′(fr，θp) And multiplying, and performing inverse Fourier transform on the product result to obtain an echo signal after matching and filtering on the distance time domain, so that the time domain autocorrelation processing is replaced by the frequency domain multiplication, and the beam forming of the transmitting dimension is also finished.
For the transmitting end beam forming method, the fuzzy function analysis of the TDA radar comprises the following specific steps:
(a) a point object model is considered. The conventional phased array radar assumes the time delays of target 1 and target 2 to be d and d + tau, and the doppler shifts to be f and f + f, respectivelydAnd the echo signals are the same in amplitude. The corresponding angles of target 1 and target 2 with respect to the transmit array antenna are θ and θ + Δ θ, respectively. The echo signals of the two targets can be expressed as:
Figure BDA0003219040500000081
Figure BDA0003219040500000091
(b) the mean square error of the two target echoes can be expressed as:
Figure BDA0003219040500000092
wherein Re () represents the operation using the real part ()*A complex conjugate operator is represented as a complex conjugate operator,
Figure BDA0003219040500000093
and
Figure BDA0003219040500000094
respectively composed of E1And E2Representing the echo signal energy of target 1 and target 2, respectively.
The above equation can be simplified as:
Figure BDA0003219040500000095
wherein the integral term is considered as TDA radar radio frequency signal SrThe fuzzy function expression of (t, theta), namely the fuzzy function expression, is as follows:
Figure BDA0003219040500000096
where the variable τ is the time delay relative to the desired matched filter peak output, and the variable fdIs the mismatch between the doppler shift of the filter design and the actual received echo doppler shift, and Δ θ is the mismatch difference between the actual target angle and the target angle estimate when the filter is designed.
The above formula is a three-dimensional fuzzy function of TDA radar time, Doppler and angle, the distance and Doppler resolution characteristics can be obtained as the traditional radar fuzzy function by analyzing the fuzzy function, and the TDA radar angle resolution capability evaluation is realized by analyzing the three-dimensional fuzzy function due to the coupling relation of the transmitting distance and the transmitting angle of the TDA radar.
Simulation experiment
The method of the invention is adopted to carry out simulation analysis on the transmitting beam forming and the fuzzy function of the TDA radar, and the simulation experiment parameters are set as follows:
the number M of transmitting array elements of TDA radar is 16, the number N of receiving array elements is 16, and the carrier frequency f of transmitting signalc16GHz, wavelength λ00.01875m, pulse width Tp10us, pulse repetition frequency PRF 8000Hz, signal bandwidth B100 MHz, array time delay delta t 0.01us, transmitting and receiving array element spacing dT＝dR＝0.009375m。
The parameter settings are as in table 1:
TABLE 1 System simulation parameters
Figure BDA0003219040500000101
2. Simulation content:
under the simulation parameters, the beam forming of the TDA radar is simulated, and the estimation based on the target angle and the distance parameter of the transmitting end is obtained, and the result is shown in fig. 3. The ultra-low sidelobe antenna pattern can be obtained by combining the receiving end beam forming, and the result is shown in fig. 4, so that a feasible method is provided for realizing flexible transmission beam control. The three-dimensional fuzzy function of the TDA radar related in the method is simulated, and the result is shown in figure 5.
As can be seen from fig. 3, the results of the distance and angle estimation of the five point targets set by the simulation are clearly visible, and the system responses are almost consistent. While the angular resolution of the point target depends on the size of the transmit array, the range resolution is related to the system bandwidth and the number of transmit arrays.
As can be seen from fig. 4, the sidelobes of the TDA radar are reduced by about 12dB compared to the pattern of the phased array radar.
Fig. 5(a) and 5(b) are fuzzy function simulation graphs when mismatch difference Δ θ between the target angle and the actual target angle estimation is 0 ° and Δ θ is 50 ° in the method of the present invention, and due to the offset of the angle, the target is not uniformly distributed over the distance, and the change of doppler also causes the difference of distance distribution, but the distance and doppler resolution characteristics are consistent under different angles; fig. 5(c) and 5(d) show the time delays τ ═ 0 and τ ═ T in the method of the present inventionpSimulation diagram of the fuzzy function at/4, it can be seen from the simulation diagram that the measurement results of the angle and the Doppler frequency are related to different distances of the target. Under the condition of different time delays, due to the time-varying characteristic of a transmitting directional diagram, the target transmitting spatial frequency changes, the change of Doppler also causes the difference of distance distribution, the target distance and the Doppler position distribution shift, but the distance and the Doppler resolution are not affected. 5(e) and 5(f) are the Doppler shift and actual reception in the method of the present inventionMismatch between the echo doppler shifts fd＝0、fdThe B/4 time ambiguity function simulation graph changes the distribution of the range dimension due to the change of the doppler frequency, and thus the angle and range estimation results have a shift in the matching result, but the resolution characteristics of the angle and range are consistent.
Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (7)

1. The transmitting end beam forming method based on the time diversity array is characterized by comprising the following steps:
step 1, establishing a TDA radar model, selecting a linear frequency modulation signal with a certain time bandwidth product as a transmitting signal, and obtaining a synthetic transmitting signal S of the TDA radar at a targetr(t, θ) and a reception signal Γ (θ, R);
the method comprises the following steps that signals transmitted between adjacent array elements of the TDA have time delay, t is time, theta is a target angle, and R is a target distance;
step 2, the receiving signal gamma (theta, R) of the TDA radar is subjected to distance compression processing to obtain a frequency domain echo signal S after distance compressioncomp(fr，θ)，frIs the range frequency; separating echo signals of the m transmitting signals in a time domain to obtain phase differences of the m transmitting signals so as to obtain a guide vector of a transmitting end;
step 3, in time domain, through searching for emission angle thetapTraversing all the distance units, and compressing the distance between the time domain echo signal and the search angle thetapAnd carrying out autocorrelation processing on the corresponding transmitting signals to construct a time-angle combined two-dimensional transmitting waveform.
2. The method for forming a transmitting-end beam based on the time diversity array according to claim 1, wherein in step 1, the establishing of the TDA radar model specifically comprises:
setting a TDA radar to have M transmitting array elements and N receiving array elements, wherein a transmitting signal between adjacent array elements has time delay; constructing M omnidirectional uniform linear arrays, taking a first transmitting antenna as a reference antenna, and expressing a transmitting signal of an M-th array element as:
Figure FDA0003219040490000011
wherein, TpDenotes the pulse width, fcDenotes the carrier frequency, gamma-B/TpIndicating the modulation frequency, B is the bandwidth, Δ t is the time delay between array elements, rect (t) is the rectangular envelope,
Figure FDA0003219040490000021
sub-step 1b, the transmit sum signal of the M transmit antennas at the target (R, θ) is expressed as:
Figure FDA0003219040490000022
wherein d isTThe distance between the array elements of the transmitting antenna is shown, and c is the speed of light;
sub-step 1c, the reception signal Γ (θ, R) of the TDA radar is represented as:
Figure FDA0003219040490000023
where λ represents the wavelength and θ represents the target azimuth.
3. The method for forming a transmitting end beam based on the time diversity array as claimed in claim 2, wherein the phase difference of the electromagnetic waves transmitted by different arrays due to different spatial distributions is expressed as:
Figure FDA0003219040490000024
according to the formula, in a time range of transmitting a pulse width, the weight value of a transmitting end of the TDA radar is time-varying, time-varying directional patterns are equivalently modulated on a transmitting array antenna, and transmitting beams point to different angles at different moments; due to the continuity of the transmitting time, the transmitting dimension of the TDA radar has a distance-angle coupling relation.
4. The method according to claim 2, wherein the distance compression processing of the received signal Γ (θ, R) of the TDA radar comprises:
multiplying the echo signal by a compensation function in the frequency domain, the compensation function being expressed as:
Figure FDA0003219040490000025
the compensated frequency domain echo signal is represented as:
Figure FDA0003219040490000031
wherein A represents the amplitude of the echo signal, ar(fr) Representing a distance frequency domain window function;
for the compensated frequency domain echo signal Scomp(frAnd theta) performing inverse Fourier transform to obtain a time domain echo signal after distance compression:
Figure FDA0003219040490000032
wherein sinc represents a sine function.
5. The method according to claim 2, wherein the m transmit signals have phase differences of:
Figure FDA0003219040490000033
then the transmit steering vector of the TDA radar can be expressed by the phase difference between the transmit array elements as:
a(θ)＝[φ1，φ2，...，φm]T。
6. the transmit-end beamforming method based on time diversity array according to claim 1, wherein the distance-compressed time domain echo signal and the search angle θpThe corresponding transmitting signal is subjected to autocorrelation processing, and the following steps can be replaced:
constructing a space-time two-dimensional matched filter in a distance frequency domain:
Hcomp′(fr，θp)＝[Sinv *(-t，θp)]fourier；
wherein, the [ alpha ], [ beta ] -a]fourierRepresenting a fourier transform operation; (.)*Represents a complex conjugate operator; sinv *(-t，θp) A time domain matched filter function based on angle search is constructed according to the echo signal after distance compression;
frequency domain multiplication processing is adopted to replace convolution operation, and the distance compressed frequency domain echo signal Scomp(frTheta) and Hcomp′(fr，θp) And multiplying, and performing inverse Fourier transform on the product result to obtain an echo signal after distance time domain matched filtering, thereby finishing the formation of the transmitting beam.
7. The transmit-side beamforming method based on time diversity array according to claim 1, wherein the M transmit antennas transmit a combined signal S at a target (R, θ)rThe fuzzy function expression of (t, θ) is:
Figure FDA0003219040490000041
wherein, (.)*Represents a complex conjugate operator; the variable τ is the time delay relative to the desired matched filter peak output, and the variable fdThe mismatching between the Doppler frequency shift designed by the filter and the Doppler frequency shift of the echo received actually is shown, and delta theta is the mismatching difference between the actual target angle and the target angle estimation when the filter is designed;
the formula is a three-dimensional fuzzy function of TDA radar time-Doppler-angle, and the resolution characteristics of distance and Doppler can be obtained through the fuzzy function; and because the transmitting distance-angle of the TDA radar is coupled, the TDA radar angle resolution capability evaluation is realized according to the three-dimensional fuzzy function.
CN202110952469.5A 2021-08-19 2021-08-19 Transmitting end beam forming method based on time diversity array Pending CN113820667A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110952469.5A CN113820667A (en) 2021-08-19 2021-08-19 Transmitting end beam forming method based on time diversity array

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110952469.5A CN113820667A (en) 2021-08-19 2021-08-19 Transmitting end beam forming method based on time diversity array

Publications (1)

Publication Number Publication Date
CN113820667A true CN113820667A (en) 2021-12-21

Family

ID=78913268

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110952469.5A Pending CN113820667A (en) 2021-08-19 2021-08-19 Transmitting end beam forming method based on time diversity array

Country Status (1)

Country Link
CN (1) CN113820667A (en)

Similar Documents

Publication Publication Date Title
Wang Phased-MIMO radar with frequency diversity for range-dependent beamforming
Wang et al. Nonuniform frequency diverse array for range-angle imaging of targets
Wang Virtual antenna array analysis for MIMO synthetic aperture radars
Huang et al. FMCW based MIMO imaging radar for maritime navigation
CN105785328B (en) The decoupling Beamforming Method of FDA distance-angles based on Subarray partition
CN108226871B (en) Diversity phased array design method based on millimeter wave collision avoidance radar
Wang et al. Range-angle-dependent beamforming by frequency diverse array antenna
CN108693511B (en) Moving target angle calculation method of time division multiplexing MIMO radar
CN109375213B (en) Frequency diversity array signal processing method based on subarray division
CN110346764B (en) MIMO radar target distance angle decoupling method
CN111352079B (en) Design method of low interception system based on frequency control array MIMO radar
Xu et al. Range-angle matched receiver for coherent FDA radars
CN111257879A (en) Method for solving millimeter wave MIMO radar target splitting based on two norms
Zhang et al. High-resolution and wide-swath SAR imaging with sub-band frequency diverse array
Chen et al. The applications and future of synthetic impulse and aperture radar
CN113238212B (en) Space-time coding-based frequency diversity array radar range resolution enhancement method
Kumari et al. A combined waveform-beamforming design for millimeter-wave joint communication-radar
Jouadé et al. Passive compressive device in an MIMO configuration at millimeter waves
CN110850383B (en) MIMO radar signal processing method based on conformal array
CN110879017B (en) Missile-borne detection device based on DBF
CN111812612A (en) Partial correlation waveform design method of MIMO radar based on subarray orthogonal LFM signal
CN113820667A (en) Transmitting end beam forming method based on time diversity array
Zhu et al. Application of frequency diverse array to resolve range ambiguity for SAR imaging
Han et al. MIMO radar fast imaging algorithm based on sub-image combination
Rommel et al. An orthogonal waveform for fully polarimetric MIMO-SAR

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