CN103941252B - Frequency modulated continuous wave radar system based on random switching array antenna - Google Patents

Abstract

The present invention proposes a kind of frequency modulated continuous wave radar system based on random switching array antenna, including: transmitter module；Anneta module, including transmitting antenna and reception antenna, transmitting antenna sends transmitting signal to scan target, and reception antenna receives target echo；Switch module, including multiple gating switches, controls multiple reception array element and is connected with single reception passage, and gating switch switches at random, so that the target echo in the reception array element being connected with the gating switch of current conducting takies reception passage；The signal and transmitting signal that receive synthesis in passage are mixed by receiver module, and the signal after mixing is carried out intermediate frequency amplification and bandpass filtering, obtain intermediate-freuqncy signal；Intermediate-freuqncy signal is carried out digital sample by processing module, and carries out follow-up process.The system of the embodiment of the present invention can effectively reduce cost and the complexity of radar system, and can effectively solve the problem that the problem that order switching switchs the time and space usage brought.

Description

Frequency modulated continuous wave radar system based on random switching array antenna

Technical field

The present invention relates to radar detection technique field, particularly to a kind of frequency modulated continuous wave radar system based on random switching array antenna.

Background technology

Frequency modulated continuous wave radar has the features such as good environmental adaptability, resolving power is high, system stability is good, and can measure distance and the radial velocity of target simultaneously.For frequency modulated continuous wave radar, the azimuth information of target can by using the mode of array antenna to obtain.Array radar has high accuracy, high resolution and high stability in azimuthal measurement, thus often as realizing the scheme that azimuth information obtains.

At present, mainly there is following several frequency modulated continuous wave radar technology:

1.DetlefsenJ,TrollT,RozmannMandZeilingerW.SystemaspectsanddesignofanautomotivecollisionwarningPNcoderadarusingwavefrontreconstruction.IEEEMTT-SInternationalMicrowaveSymposiumDigest,1992:625-628.Many reception channel array frequency modulated continuous wave radars.This technology adopts individual antenna to carry out signal transmitting, and the reception signal of multiple array elements is sampled by multiple reception passages simultaneously, completes the estimation of the imaging of target and orientation, distance, speed.But, the shortcoming of this method is in that the use receiving passage more, makes system complexity high, and volume is relatively big, relatively costly.

2.LiYandFengZH.SwitchantennaarraywithsinglereceivingchannelforFMCWradar.Proc.InternationalSymp.AntennasPropagation,2000;1629-1632.Single receiving channel array frequency modulated continuous wave radar.This technology proposes a kind of time-multiplexed mode, and each array element is shared one according to certain sequential and received passage, and the cost of system and complexity all have reduction.But the acquisition time having drawbacks in that data of this method is longer, carry out orientation, distance, speed estimation need multiple signals launch the cycle could obtain enough data.

3.S.Tokoro,K.Kuroda,andA.Kawakubo.Automotiveelectronicallyscannedmillimeter-waveradar.SICE2003AnnualConference,vol.1.IEEE,2003,pp.42–47.Single-shot penetrates cycle time division multiplexing mode.This technology proposes the working method receiving array element switch rapid sequential switching, within a transmitting cycle, can complete required each array element and receive the collection of data.But this method have drawbacks in that the phase contrast receiving signal owing to closing on array element not only can cause due to the angle of target, simultaneously as the time of switch switching causes, this mode can cause time and space usage problem.

4. Wang Peng. the target bearing Joint of array radar is estimated and high-resolution imaging. [master thesis]. and Beijing: Tsing-Hua University, 2010.This technical perfection single-shot penetrates the time division multiplexing mode in cycle, provides corresponding signal model.By analyzing the signal model that working method two kinds special switches at a slow speed and quickly switches, itself and multichannel array signal model are unified, on this basis, the On The Choice of time division multiplexing mode in real system is discussed.But this technology remains restricted to the mode of switching sequence switching, it is impossible to the problem effectively solving time and space usage.

Summary of the invention

It is contemplated that at least solve one of above-mentioned technical problem.

For this, it is an object of the invention to propose a kind of frequency modulated continuous wave radar system based on random switching array antenna, this system can be accurately obtained the information such as the distance of target, speed, orientation, effectively reduce cost and the complexity of radar system, and can effectively solve the problem that the problem that order switching switchs the time and space usage brought.

To achieve these goals, embodiments of the invention propose a kind of frequency modulated continuous wave radar system based on random switching array antenna, including: transmitter module, described transmitter module is for producing the transmitting signal needed for radar；Anneta module, described Anneta module includes the transmitting antenna being made up of single array element and the reception antenna being made up of multiple reception array elements, and described transmitting antenna is used for sending transmitting signal to scan target, and described reception antenna is used for receiving target echo；Switch module, described switch module includes the multiple gating switches being connected with multiple reception array element one_to_one corresponding, the plurality of gating switch controls the plurality of reception array element and is connected with single reception passage, the plurality of gating switch switches at random, so that the target echo in the reception array element being connected with the gating switch of current conducting takies described reception passage；Receiver module, described receiver module is for being mixed the signal synthesized in described single reception passage and described transmitting signal, and the signal after mixing is carried out intermediate frequency amplification and bandpass filtering, obtains intermediate-freuqncy signal；Processing module, described processing module for carrying out digital sample to described intermediate-freuqncy signal, and carries out follow-up process.

The information such as the frequency modulated continuous wave radar system based on random switching array antenna according to embodiments of the present invention, adopts the system of Continuous Wave with frequency modulation, and target and terrain environment to scene are detected, it is possible to effective range-to-go, speed, orientation.Additionally, this system adopts the structure of random switching array antenna, multiple reception antenna time division multiplexes one are made to receive passage, namely single reception passage is used, within a signal transmitting cycle, the echo-signal (target echo) that each reception array-element antenna is received by speed-sensitive switch switching is adopted to carry out gating, thus effectively reducing radar system cost and complexity, and the problem efficiently solving the time and space usage that order switching switch brings.It addition, when switching switching rate and system bandwidth is limited, use the random mode switching gating switch, increase the not fuzzy distance of radar surveying, reduce the requirement to switch switching rate and system bandwidth.

It addition, the frequency modulated continuous wave radar system based on random switching array antenna according to the above embodiment of the present invention can also have following additional technical characteristic:

In some instances, described transmitting signal is the radar signal x of Continuous Wave with frequency modulation₀(t), and:

x₀(t)=exp{j2π(f₀t+φ(t))},φ(t)=αt²/ 2,0≤t < T,

Wherein, f₀For transmitting carrier frequency, frequency modulation rate B/T, B that α is Continuous Wave with frequency modulation are transmitting signal swept bandwidth, and T is the transmitting cycle.

In some instances, described target echo x_kT () is represented by following formula:

x_k(t)=α₀x₀(t-t_k),t_k=2(r+vt)/c+τ_k,τ_k=(dsin θ/c) (k-1), k=1 ..., M,

Wherein, k represents that kth receives array element, and r, v, θ respectively target is relative to the distance of radar, radial velocity and orientation, a₀Representing target reflection factor, c is the light velocity, and d is for receiving array element distance, τ_kRepresent that kth receives array element and receives the time delay that array element reflected signal arrives relative to the 1st.

In some instances, the signal y after described mixing_nkT () is represented by equation below:

y_nk(t)=aexp{-j(2πη(((n-1)M+(k-1))T_sw+t-((n-1)M+(k-1))T_sw))}·

exp{-j(2π(dsinθ/λ)(M_nk-1))}+n(t),

((n-1)M+(k-1))T_sw≤t<((n-1)M+k)T_sw,

Wherein, T_swRepresenting the conducting state retention time of each gating switch, M represents the quantity receiving array element, M_nkRepresenting and occupy the array element numbering receiving passage in the n-th rotational cycle in kth time division multiplex interval, η is called frequency of distance, andR, v, θ and a₀Represent respectively each target relative to radar distance, radial velocity, angle and reflection coefficient, n (t) is for receiving channel noise.

In some instances, described processing module, for described intermediate-freuqncy signal is carried out digital sample, obtains digital signal y_nkIf, ω=sin θ, calculate described digital signal y_nkAuto-correlation function χ (Δ η, Δ ω) in frequency of distance-orientation, described auto-correlation function χ (Δ η, Δ ω) is calculated by equation below:

$\mathrm{\&chi;}(\mathrm{\&Delta;\&eta;},\mathrm{\&Delta;\&omega;})=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}}_{+2\mathrm{\&pi;}(\mathrm{d\&Delta;\&omega;}/\mathrm{\&lambda;})(M_{\mathrm{nk}}-1)\left)\right\}}^{\exp \{-j\left(2\mathrm{\&pi;\&Delta;\&eta;}(((n-1)M+(k-1)T_{\mathrm{sw}}\right)},$

Wherein, T_swRepresenting the conducting state retention time of each gating switch, M represents the quantity receiving array element.

The additional aspect of the present invention and advantage will part provide in the following description, and part will become apparent from the description below, or is recognized by the practice of the present invention.

Accompanying drawing explanation

Above-mentioned and/or the additional aspect of the present invention and advantage are from conjunction with will be apparent from easy to understand the accompanying drawings below description to embodiment, wherein:

Fig. 1 is the structured flowchart of frequency modulated continuous wave radar system based on random switching array antenna according to an embodiment of the invention；

Fig. 2 is antenna and the gating switch structural representation of frequency modulated continuous wave radar system based on random switching array antenna in accordance with another embodiment of the present invention；

Fig. 3 is the theory diagram of frequency modulated continuous wave radar system based on random switching array antenna in accordance with another embodiment of the present invention；

Fig. 4 is that the radar of frequency modulated continuous wave radar system based on random switching array antenna according to an embodiment of the invention receives array element and receives the schematic diagram of target echo；

Fig. 5 is the random principle schematic switching gating switch of frequency modulated continuous wave radar system based on random switching array antenna according to an embodiment of the invention；And

Fig. 6 is the ambiguity function contrast schematic diagram that order switching gating switch and random switching gating switch obtain according to an embodiment of the invention.

Detailed description of the invention

Being described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of same or like function from start to finish.The embodiment described below with reference to accompanying drawing is illustrative of, and is only used for explaining the present invention, and is not considered as limiting the invention.

In describing the invention, it will be appreciated that, term " " center ", " longitudinal direction ", " transverse direction ", " on ", D score, " front ", " afterwards ", " left side ", " right side ", " vertically ", " level ", " top ", " end ", " interior ", orientation or the position relationship of the instruction such as " outward " are based on orientation shown in the drawings or position relationship, it is for only for ease of the description present invention and simplifies description, rather than the device of instruction or hint indication or element must have specific orientation, with specific azimuth configuration and operation, therefore it is not considered as limiting the invention.Additionally, term " first ", " second " are only for descriptive purposes, and it is not intended that indicate or hint relative importance.

In describing the invention, it is necessary to explanation, unless otherwise clearly defined and limited, term " installation ", " being connected ", " connection " should be interpreted broadly, for instance, it is possible to it is fixing connection, it is also possible to be removably connect, or connect integratedly；Can be mechanically connected, it is also possible to be electrical connection；Can be joined directly together, it is also possible to be indirectly connected to by intermediary, it is possible to be the connection of two element internals.For the ordinary skill in the art, it is possible to concrete condition understands above-mentioned term concrete meaning in the present invention.

With reference to as explained below and accompanying drawing, it will be clear that these and other aspects of embodiments of the invention.Describe at these and in accompanying drawing, specifically disclose some particular implementation in embodiments of the invention, representing some modes of the principle implementing embodiments of the invention, but it is to be understood that the scope of embodiments of the invention is not limited.On the contrary, all changes within the scope of embodiments of the invention include falling into attached claims spirit and intension, amendment and equivalent.

Below in conjunction with accompanying drawing, the frequency modulated continuous wave radar system based on random switching array antenna according to embodiments of the present invention is described.

Fig. 1 is the structured flowchart of frequency modulated continuous wave radar check system based on random switching array antenna according to an embodiment of the invention.As it is shown in figure 1, according to an embodiment of the invention based on the FM-CW System 100 of random switching array antenna, including: transmitter module 110, Anneta module 120, switch module 130, receiver module 140 and processing module 150.

Specifically, transmitter module 110 is for producing the transmitting signal needed for radar.

Shown in Fig. 2, Anneta module 120 includes the transmitting antenna being made up of single array element and the reception antenna being made up of multiple reception array elements.Wherein, transmitting antenna is used for sending transmitting signal to scan target, and reception antenna is used for receiving target echo.In one embodiment of the invention, the signal radar signal x for example with Continuous Wave with frequency modulation is launched₀(t), and more specifically,

x₀(t)=exp{j2π(f₀t+φ(t))},φ(t)=αt²/ 2,0≤t < T,

Wherein, f₀For transmitting carrier frequency, frequency modulation rate B/T, B that α is Continuous Wave with frequency modulation are transmitting signal swept bandwidth, and T is the transmitting cycle.Further, in another embodiment, launching signal after target reflection, reflected signal is received by reception antenna.In a concrete example, as shown in Figure 4, wherein left figure show launch signal and target echo frequency over time, wherein solid line represents transmitting signal, and dotted line represents target echo.As can be seen from Figure 4 under the system of Continuous Wave with frequency modulation, will there is a stable difference on the frequency η in the receiving and transmitting signal of time phase difference Δ t, namely relevant with speed with the distance of target frequency of distance.In Fig. 4, right figure represents that the different array element that receives receives the difference of signal, and reception array element distance is d, is the target of θ for azimuth, and the wave path-difference that adjacent reception antenna receives is dsin θ.Further, in specific implementation process, receive array element by the spatial order receiving array element to M and be numbered, then kth receives the target echo x that array element receives_kT () is represented by following formula:

x_k(t)=a₀x₀(t-t_k),t_k=2(r+vt)/c+τ_k,τ_k=(dsin θ/c) (k-1), k=1 ..., M,

Wherein, k represents that kth receives array element, and r, v, θ respectively target is relative to the distance of radar, radial velocity and orientation, a₀Representing target reflection factor, c is the light velocity, and d is for receiving array element distance, τ_kRepresent the time delay that kth array element arrives relative to the 1st array element reflected signal.

As a concrete example, in specific implementation process, above-mentioned transmitting antenna is for observing the target in its front one orientation.In conjunction with, shown in Fig. 2 and Fig. 3, specifically, adopting superposed single array element to constitute transmitting antenna, be positioned at M reception array element composition reception antenna of bottom, single reception passage is adopted time-multiplexed structure by each array element that receives.In the specific implementation, transmitting antenna produces the transmitting signal of Continuous Wave with frequency modulation, and when being irradiated to target, feedback reflector signal, M road receives array element and receives target echo.

Switch module 130 includes the multiple gating switches being connected with multiple reception array element one_to_one corresponding, multiple gating switches control multiple reception array elements and are connected with single reception passage, in the specific implementation, multiple gating switches switch at random, so that the target echo in the reception array element being connected with the gating switch of current conducting takies reception passage.In other words, the target echo that namely respectively reception array element receives needs to merge into a road signal in reception passage.

As a concrete example, M receives array element and adopts time-multiplexed mode to use one to receive passage, each reception array element adopts the mode of random switching, and switching mode is (situation here for M=7) as shown in Figure 5.The mode that reflected signal merges is for using one group of gating switch, and each reception array element can use a corresponding connected switching gate.When kth gating switch turns on, kth receives the target echo of array element reception will take reception passage.Further, have only to switch the state of this group gating switch by the mode of random switching, and ensure that each moment only one of which gating switch is conducting state, so that it may so that each road receive the target echo timesharing that array element receives take reception passage, merge into a road signal receiving in passage.More specifically, wherein, each gating switch is T in the retention time of conducting state_sw, it is called a time division multiplex interval.When there being M to receive array element, by the equal gating of gating switch corresponding for each reception array element once, the target echo that each reception array element receives is made all to take T in receiving passage_swTime, thus MT_swTime be called a rotational cycle.Further, each transmitting cycle T is made up of multiple complete rotational cycles.On the other hand, namely above-mentioned random switching mode refers to and all uses a random sequence generator in each rotational cycle, is undertaken randomly ordered by the numbering of M gating switch, and each gating switch is according to this random sequence gating T successively_swTime, the corresponding target echo receiving array element reception receives one time division multiplex interval T of passage according to this random taking of sequence timesharing_sw.Wherein, in a receiving cycle, including multiple complete rotational cycles, after a rotational cycle terminates, immediately enter next rotational cycle.

Receiver module 140 is for being mixed the target echo of synthesis in single reception passage with launching signal, and the signal after mixing is carried out intermediate frequency amplification and bandpass filtering treatment, obtains intermediate-freuqncy signal.

As a concrete example, in one embodiment of the invention, according to the random switching mode designed, M is made_nkRepresent and the n-th rotational cycle occupies in kth time division multiplex interval the reception array element numbering receiving passage.When there being a target in scene, each target is relative to the distance of radar system 100, radial velocity, angle and reflection coefficient respectively r, v, θ and a₀, orderη represents frequency of distance.Wherein, the frequency of distance of each target and the speed of target and distance dependent, when target is static, frequency of distance is only determined by distance, and therefore frequency of distance is a kind of reflection (can be respectively obtained distance and the speed of target by the method for target range, speed decoupling) to target range.Further, orderReception channel noise is n (t), then now target echo passes through mixing, the signal y after mixing with launching signal_nkT () can be represented by equation below:

y_nk(t)=aexp{-j(2πη(((n-1)M+(k-1))T_sw+t-((n-1)M+(k-1))T_sw))}·

exp{-j(2π(dsinθ/λ)(M_nk-1))}+n(t),

((n-1)M+(k-1))T_sw≤t<((n-1)M+k)T_sw,

Wherein, M_nkRepresenting and occupy the array element numbering receiving passage in the n-th rotational cycle in kth time division multiplex interval, η is called frequency of distance, andR, v, θ and a₀Represent respectively each target relative to radar system 100 distance, radial velocity, angle and reflection coefficient, n (t) is for receiving channel noise.

Further, to the signal y after above-mentioned mixing_nkT () carries out intermediate frequency and amplifies and obtain intermediate-freuqncy signal after bandpass filtering.

Processing module 150 for carrying out digital sample to intermediate-freuqncy signal, and carry out subsequent treatment and obtain the information of target.Specifically, in one embodiment of the invention, processing module 150, for intermediate-freuqncy signal is carried out digital sample, obtains digital signal y_nk.As a concrete example, for instance adopt sample frequency f_sIntermediate-freuqncy signal is carried out digital sample, with the digital signal y after being sampled_nk.Further, make ω=sin θ, and calculate this digital signal y_nkAuto-correlation function (i.e. ambiguity function) χ (Δ η, Δ ω) in frequency of distance-orientation, wherein, this auto-correlation function (ambiguity function) χ (Δ η, Δ ω) can be calculated by equation below:

$\mathrm{\&chi;}(\mathrm{\&Delta;\&eta;},\mathrm{\&Delta;\&omega;})=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}}_{+2\mathrm{\&pi;}(\mathrm{d\&Delta;\&omega;}/\mathrm{\&lambda;})(M_{\mathrm{nk}}-1)\left)\right\}}^{\exp \{-j\left(2\mathrm{\&pi;\&Delta;\&eta;}(((n-1)M+(k-1)T_{\mathrm{sw}}\right)},$

Wherein, T_swRepresenting the conducting state retention time of each gating switch, M represents the quantity receiving array element.Further, the performance of radar system 100 can be analyzed according to this auto-correlation function (ambiguity function) χ (Δ η, Δ ω).

In addition, it is necessary to illustrate, when random switching, ambiguity function is needle-like, the problem being absent from time and space usage, and further, the not ambiguity interval in frequency of distance reaches (-f_s/2,f_s/2)。

Further, in order to the advantage of random switching is described, the ambiguity function of switching at random with order switching is contrasted.Specifically, order switching, refer in a rotational cycle, switch switch according to the order of the corresponding array element numbering of switch, in each rotational cycle, be sequentially switched to M from 1.As a concrete example, order switching contrasts as shown in Figure 6 with random switching ambiguity function.Abscissa in Fig. 6 represents by the normalized frequency of distance increment Delta η/f of sample frequency_s, vertical coordinate represents the increment Delta ω in orientation.Wherein, when left figure is order switching, the ambiguity function interval f on the diagonal of order switching_sThere are multiple peak values in/M, and this will cause fuzzy problem in the frequency of distance Combined estimator with orientation, and the not ambiguity interval in frequency of distance is (-f_s/2M,f_s/2M).When right figure is random switching, ambiguity function presents figure spike, and the problem being absent from time and space usage, the not ambiguity interval in frequency of distance reaches (-f_s/2,f_s/2).Therefore, the mode of random switching efficiently solves the problem of time and space usage, and when identical sample rate, the not ambiguity interval in frequency of distance expands to M times of order switching.

The information such as the frequency modulated continuous wave radar system based on random switching array antenna according to embodiments of the present invention, adopts the system of Continuous Wave with frequency modulation, and target and terrain environment to scene are detected, it is possible to effective range-to-go, speed, orientation.Additionally, this system adopts the structure of random switching array antenna, multiple reception antenna time division multiplexes one are made to receive passage, namely single reception passage is used, within a signal transmitting cycle, the echo-signal (target echo) that each reception array-element antenna is received by speed-sensitive switch switching is adopted to carry out gating, thus effectively reducing radar system cost and complexity, and the problem efficiently solving the time and space usage that order switching switch brings.It addition, when switching switching rate and system bandwidth is limited, use the random mode switching gating switch, increase the not fuzzy distance of radar surveying, reduce the requirement to switch switching rate and system bandwidth.

In the description of this specification, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means in conjunction with this embodiment or example describe are contained at least one embodiment or the example of the present invention.In this manual, the schematic representation of above-mentioned term is not necessarily referring to identical embodiment or example.And, the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiments or example.

Although an embodiment of the present invention has been shown and described, it will be understood by those skilled in the art that: these embodiments can being carried out multiple change, amendment, replacement and modification when without departing from principles of the invention and objective, the scope of the present invention is by claim and equivalency thereof.

Claims (1)

1. the frequency modulated continuous wave radar system based on random switching array antenna, it is characterised in that including:

Transmitter module, described transmitter module is for producing the transmitting signal needed for radar, and wherein, described transmitting signal is the radar signal x of Continuous Wave with frequency modulation₀(t), and:

x₀(t)=exp{j2 π (f₀T+ φ (t)) }, φ (t)=α t²/ 2,0≤t < T,

Wherein, f₀For transmitting carrier frequency, frequency modulation rate B/T, B that α is Continuous Wave with frequency modulation are transmitting signal swept bandwidth, and T is the transmitting cycle；

Anneta module, described Anneta module includes the transmitting antenna being made up of single array element and the reception antenna being made up of multiple reception array elements, and described transmitting antenna is used for sending transmitting signal to scan target, and described reception antenna is used for receiving target echo, wherein, described target echo x_kT () is represented by following formula:

x_k(t)=α₀x₀(t-t_k),t_k=2 (r+vt)/c+ τ_k,τ_k=(dsin θ/c) (k-1), k=1 ..., M,

Wherein, M represents the sum receiving array element, and k represents that kth receives array element, and r, v, θ respectively target is relative to the distance of radar, radial velocity and orientation, a₀Representing target reflection factor, c is the light velocity, and d is for receiving array element distance, τ_kRepresent that kth receives array element and receives the time delay that array element reflected signal arrives relative to the 1st；

Switch module, described switch module includes the multiple gating switches being connected with multiple reception array element one_to_one corresponding, the plurality of gating switch controls the plurality of reception array element and is connected with single reception passage, the plurality of gating switch switches at random, so that the target echo in the reception array element being connected with the gating switch of current conducting takies described reception passage；

Receiver module, described receiver module is for being mixed the signal synthesized in described single reception passage and described transmitting signal, and the signal after mixing is carried out intermediate frequency amplification and bandpass filtering, obtains intermediate-freuqncy signal, wherein, the signal y after described mixing_nkT () is represented by following formula:

y_nk(t)=aexp{-j (2 π η (((n-1) M+ (k-1)) T_sw+t-((n-1)M+(k-1))T_sw))}·

exp{-j(2π(dsinθ/λ)(M_nk-1)) }+n (t),

((n-1)M+(k-1))T_sw≤t<((n-1)M+k)T_sw

Wherein, T_swRepresenting the conducting state retention time of each gating switch, M represents the quantity receiving array element, M_nkRepresenting and occupy the array element numbering receiving passage in the n-th rotational cycle in kth time division multiplex interval, η is called frequency of distance and η=2 α r/c+2v/ λ, R, v, θ and a₀Represent respectively each target relative to radar distance, radial velocity, angle and reflection coefficient, c is the light velocity, f₀For transmitting carrier frequency, d is for receiving array element distance, and n (t) is for receiving channel noise, and α is the frequency modulation rate B/T of Continuous Wave with frequency modulation, and B is for launching signal swept bandwidth, and T is the transmitting cycle；

Processing module, described processing module, for described intermediate-freuqncy signal is carried out digital sample, obtains digital signal y_nkIf, ω=sin θ, calculate described digital signal y_nkAuto-correlation function χ (Δ η, Δ ω) in frequency of distance-orientation, wherein, described auto-correlation function χ (Δ η, Δ ω) is calculated by equation below:

$\mathrm{\&chi;}(\mathrm{\&Delta;}\mathrm{\&eta;},\mathrm{\&Delta;}\mathrm{\&omega;})=\underset{n=1}{\overset{N}{\&Sigma;}}\underset{k=1}{\overset{K}{\&Sigma;}}\begin{array}{c}\exp \{-j\left(2\mathrm{\&pi;}\mathrm{\&Delta;}\mathrm{\&eta;}\right(\left(\right(n-1)M+(k-1)T_{sw})\\ +2\mathrm{\&pi;}(d\mathrm{\&Delta;}\mathrm{\&omega;}/\mathrm{\&lambda;})(M_{nk}-1)\left)\right\}\end{array},$

Wherein, T_swRepresenting the conducting state retention time of each gating switch, M represents the quantity receiving array element, and d is for receiving array element distance, M_nkRepresent and the n-th rotational cycle occupies in kth time division multiplex interval the array element numbering receiving passage.