CN104574536A - RSU (Road Side Unit) equipment of ETC (Electronic Toll Collection) system - Google Patents

Abstract

The invention relates to RSU (Road Side Unit) equipment of an ETC (Electronic Toll Collection) system. The equipment comprises a DSRC microwave antenna and a read-write controller, wherein the DSRC (Dedicated Short Range Communication) microwave antenna comprises an L-type antenna array comprising a plurality of array elements and used for DSRC microwave communication with OBU (On Board Unit) equipment, a multi-channel radio-frequency receiving/transmitting component used for converting a microwave signal received through the array elements into an intermediate-frequency signal, a communication control module used for analyzing a DSRC protocol and controlling the multi-channel radio-frequency receiving/transmitting component to receive the microwave signal, and a positioning module used for determining the position of an OBU by a super-resolution spatial spectrum algorithm according to the intermediate-frequency signal and sending the position information of the OBU to the read-write controller for controlling read-write operation of the DSRC microwave antenna according to the position information; each channel is connected with an antenna array element. By implementing the equipment, the problems of poor positioning precision of the OBU and incorrect fee deduction of a non-stop ETC system in an existing ETC system can be solved.

Description

The RSU equipment of ETC system

Technical field

The present invention relates to intelligent transportation field, more particularly, relate to roadside unit (Road Side Unit the is called for short RSU) equipment in a kind of electric non-stop toll (Electronic Toll Collection is called for short ETC) system.

Background technology

Along with extensive use and the fast development of intelligent transport technology, RSU equipment needs to have more strong function, deals with day by day complicated traffic environment and application requirement.Because the travel situations of vehicle on road is complicated and changeable, RSU system is caused easily to occur lie interference or the phenomenon with car interference, occur that error count such as to take at the operation, have impact on the normal work of ETC system, therefore, the demand of accurate judgement vehicle present position on track is very urgent, and this possesses the function of the vehicle loading OBU being carried out to accurate, errorless location with regard to needing RSU equipment.

The method that the RSU equipment in the RSU equipment of current use and Patents document with positioning function realizes location is by arranging multiple reception antenna array element, by carrying out certain weighting process to the array element of diverse location, beam scanning is carried out to the orientation of information source, with the process of checking from certain special angle arriving signal, i.e. DBF technology.The method is when there is polynary coherent in actual environment (as multipath effect, signal reflex etc.), if when the differential seat angle between the incidence angle of the incidence angle of interference signal and required signal is less than beamwidth, the method cannot provide the real angle of desired signal, the angle caused given by Wave beam forming will be increased, even the angle of arrival of non-required interference signal is thought by mistake be the angle of arrival of desired signal.Therefore, when ETC the lane in which the drivers should pay fees circumstance complication, the method positioning precision is poor, accurately can not locate OBU and to the vehicle loading this OBU, likely cause deducting fees by mistake, attract unnecessary dispute.

Summary of the invention

The technical problem to be solved in the present invention is, for the defect of the positioning precision difference of prior art, provides a kind of RSU equipment adopting the ETC system of inverted-L antenna array.

The technical solution adopted for the present invention to solve the technical problems is: the RSU equipment constructing a kind of ETC system, comprises DSRC microwave antenna and read-write controller, and wherein, described DSRC microwave antenna comprises:

Inverted-L antenna array, it comprises multiple microstrip antenna element, for transmitting and receiving OBU microwave signal, to carry out DSRC microwave communication with OBU equipment;

Multi-channel radio frequency receives/send out assembly, and for converting the microwave signal received by described array element to intermediate-freuqncy signal, the number of active lanes that assembly was received/sent out to wherein said multi-channel radio frequency is corresponding with the number of described array element, and each expanding channels array element;

Communication control module, for carry out DSRC communications protocol parsing and control described multi-channel radio frequency receive/send out assembly receive microwave signal;

Locating module, for adopting the spatial spectrum algorithm of super-resolution to determine the position of OBU according to described intermediate-freuqncy signal, and the positional information of described OBU is sent to described read-write controller, so that described read-write controller controls the read-write operation of described DSRC microwave antenna according to described positional information.

Implement the present invention, there is following beneficial effect: because employing inverted-L antenna array, spatial spectrum algorithm carry out signal extraction to the coherent under roadway environments complicated and changeable, effectively improve the positioning precision of label under environment complicated and changeable, thus high-precision location can be carried out to label, therefore, the problem that prior art positioning precision is poor, no-stop charging system is deducted fees easily makes mistakes can be solved.Not only solve the interference problem between adjacent lane, decrease unnecessary dispute, and the accurate location to being equipped with label vehicle in the free streaming system in city can be realized.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described, in accompanying drawing:

Fig. 1 is the schematic diagram of structure of the RSU equipment of ETC system of the present invention;

Fig. 2 is the Organization Chart of the locating module in the RSU equipment of ETC system of the present invention;

Fig. 3 is the Organization Chart of the communication control module in the RSU equipment of ETC system of the present invention;

Fig. 4 is the inverted-L antenna array junctions composition in the RSU equipment of ETC system of the present invention;

Fig. 5 is the positioning flow figure determining OBU vehicle location in the RSU equipment of ETC system of the present invention.

Embodiment

The present invention constructs a kind of RSU equipment of ETC system, and it carries out super-resolution location based on inverted-L antenna array, employing spatial spectrum algorithm to coherent.In an embodiment of the present invention, provide a kind of accurate positioning method based on inverted-L antenna array, by the microwave signal of L-type array antenna received board units (OBU), the spatial spectrum algorithm of super-resolution is adopted to calculate azimuth between OBU and inverted-L antenna array, the angle of pitch, and then realize the super-resolution location to being equipped with OBU vehicle according to the position of inverted-L antenna array, azimuth and the angle of pitch, under solving roadway environments complicated and changeable, the problem of no-stop charging system positioning precision difference.

Fig. 1 is the schematic diagram of structure of the RSU equipment of ETC system of the present invention.As shown in Figure 1, the RSU equipment of ETC system of the present invention comprises DSRC microwave antenna 10 and read-write controller 20.DSRC microwave antenna 10 is the aerial arrays be made up of many microstrip antenna elements, is responsible for the microwave signal being received OBU transmitting by multiple channel; Read-write controller 20 controls transmitting and receiving data and processes the module of receiving and sending messages to host computer.DSRC microwave antenna 10 carries out exchanges data with the communication modes of DSRC agreement and OBU and IC-card, Real-time Collection and the pay imformation upgraded in label and IC-card, and by serial port and cyber-net communication.

As shown in Figure 1, DSRC microwave antenna 10 comprises: assembly 12, communication control module 14 and locating module 16 are received/sent out to inverted-L antenna array 11, multi-channel radio frequency.Wherein, inverted-L antenna array 11 comprises multiple microstrip antenna element, for transmitting and receiving microwave signal, to carry out DSRC microwave communication with OBU equipment.Multi-channel radio frequency is received/is sent out assembly 12 and is connected with inverted-L antenna array 11, each expanding channels array element, and the number of active lanes that assembly was received/sent out to multi-channel radio frequency is corresponding with the number of array element; Multi-channel radio frequency is received/is sent out assembly 12 and converts the microwave signal received by array element to intermediate-freuqncy signal.Locating module 16 is received/is sent out assembly 12 and is connected with multi-channel radio frequency, the spatial spectrum algorithm of super-resolution is adopted to determine the position of OBU according to intermediate-freuqncy signal, and the positional information of OBU is sent to read-write controller 20, so that read-write controller 20 is according to the read-write operation of the positional information control DSRC microwave antenna 10 of OBU.Assembly 12 and locating module 16 are received/sent out to communication control module 14 respectively connecting multi-channel radio frequency, be responsible for the parsing of DSRC communications protocol and complete the control of multi-channel radio frequency being received/being sent out assembly, such as controlled by read-write controller, according to the interval of launching, receive, or control according to the arrival bearing angle of OBU.In one embodiment, the control command that assembly is sent by RS232 serial ports reception communication control module is received/sent out to multi-channel radio frequency, complete the setting of RF processing unit frequency and mode of operation, the microwave signal that each for inverted-L antenna array submatrix receives is carried out the process such as mixing, filtering and obtain intermediate-freuqncy signal.

The positioning flow of OBU vehicle location is determined as shown in Figure 5 in the RSU equipment of ETC system of the present invention.First, in step 510, multiple microstrip antenna elements of inverted-L antenna array receive the microwave signal of OBU transmission respectively, receive/send out after component synchronization carries out mixing, filtering process to obtain intermediate-freuqncy signal by multi-channel radio frequency; Then, in step 520, locating module is carried out acquisition process by A/D to multichannel intermediate-freuqncy signal and the multichannel digital signal gathered to be estimated by the information source of Digital Down Convert, coherent signal and front and back calculate azimuth between inverted-L antenna array and OBU, the angle of pitch in real time to smoothing algorithm etc.; Finally, in step 530, locating module determines according to the position of inverted-L antenna array the positional information that OBU vehicle is housed.

Locating module is the main functional modules realizing above-mentioned positioning flow.Locating module is used for the two-dimensional coordinate information determining OBU according to the microwave signal collected, and is responsible for coding/decoding, the modulating/demodulating of baseband signal simultaneously.Fig. 2 is the Organization Chart of locating module one embodiment in the RSU equipment of ETC system of the present invention.As shown in Figure 2, locating module comprises: A/D acquisition module 162, Digital Down Converter Module 164, location Calculation module 166 and Base-Band Processing and communication control module 168.Further, location Calculation module 166 comprises: number of source estimation module 166a, direction of arrival computing module 166b and OBU location confirmation module 166c.In one embodiment, locating module adopts software and hardware combining mode to realize, and wherein A/D acquisition module is hardware, and other algorithm is all at FPGA, MCU inside software simulating.

In operation, A/D acquisition module 162 receives for synchronous acquisition from described multi-channel radio frequency/sends out the intermediate-freuqncy signal of assembly, and carries out analog-to-digital conversion, is digital signal by analog-signal transitions; Digital Down Converter Module 164, for the intermediate-freuqncy signal after analog-to-digital conversion being carried out in-phase component and the quadrature component that Digital Down Convert process obtains signal, forms the digital signal of plural form, and extracts, and reduces the speed of signal; Location Calculation module 166 is for obtaining the positional information of OBU according to the digital signal of described plural form, such as, in certain embodiments, location Calculation module 166 is under estimating roadway environments (relevant multi-path jamming), the number of signal source (comprising OBU and coherent interference source) according to number of source, adopt and determine azimuth between positioner and OBU, the angle of pitch in conjunction with MUSIC (multiple signal component) algorithm of front-rear space smooth technology, and/or the two-dimensional coordinate information of OBU; Base-Band Processing and communication control module 168 are for processing described positional information, and give described read-write controller by the base band signal transmission comprising described positional information that obtains after process, and receive and to go forward side by side row relax from the read-write operation instruction of described read-write controller, and the Signal transmissions comprising described read-write operation instruction obtained after process to described multi-channel radio frequency is received/send out assembly.Such as, in certain embodiments, Base-Band Processing and communication control module are used for the coding/decoding of baseband signal, modulating/demodulating and HDLC and resolve, and the information parsed is transferred to DSRC microwave antenna read-write controller together with positioning result.

Positional information can be the two-dimensional coordinate information of OBU, also can be OBU relative to the azimuth of inverted-L antenna array and the angle of pitch, when determining that the two-dimensional coordinate of OBU or this azimuth and the angle of pitch are in predetermined scope, can determine, in effective track that this RSU covers, can read and write.

Adopting the spatial spectrum algorithm of super-resolution to determine in the process of the position of OBU, number of source estimation module 166a is used for the dependency structure and the information source number that adopt two-way level and smooth order algorithm estimated signal source according to the digital signal of the plural form received; Direction of arrival computing module 166b is used for adopting front-rear space smooth algorithm and MUSIC algorithm to calculate the direction of arrival of each information source according to the dependency structure of described signal source and information source number; And OBU location confirmation module 166c is used for the direction of arrival of the spectrum peak confirmation OBU composed according to the MUSIC corresponding to each information source, and generate OBU positional information.

In the RSU equipment of ETC system of the present invention, inverted-L antenna array except the microwave signal for receiving OBU equipment, also for OBU equipment send microwave signal.Communication control module 14 controls for receiving/send out assembly to multi-channel radio frequency, makes it enter accepting state or emission state as required.

Fig. 3 is the Organization Chart of the communication control module in RSU equipment one embodiment of ETC system of the present invention.As shown in Figure 3, communication control module comprises: protocol resolution module 142, receive path configuration module 144 and transmission channel configuration module 146.Wherein, protocol resolution module 142 is for carrying out the parsing of DSRC communications protocol to described intermediate-freuqncy signal; Receive path configuration module 144 carries out reception operation for the whole passages receiving/send out assembly in accepting state configuration multi-channel radio frequency; Transmission channel configuration module 146 carries out firing operation for receiving/send out assembly in emission state configuration multi-channel radio frequency by the mode (such as by multichannel in-phase stacking) of signal syntheses.

The RSU equipment of ETC system of the present invention adopts inverted-L antenna array as reception antenna.The micro-strip antenna array that inverted-L antenna array is normally made up of 4 ~ 8 submatrixs also realizes circular polarization by double-fed point orthogonal manner.Inverted-L antenna array be a kind of equidistant evenly and the azimuth of incoming signal and the antenna array structure of the angle of pitch can be estimated simultaneously.The antenna array structure that the two-dimentional angular estimation that prior art adopts is conventional, as uniform circular array, though can provide 0 ° ~ 360 ° without fuzzy, omnibearing two-dimentional angle information, but it is more subject to the impact of mutual lotus root between antenna; Another planar array array element quantity is more, amount of calculation is comparatively large, structure is more complicated.The antenna array structure conventional relative to other two-dimentional angular estimation, inverted-L antenna array opposed configuration is simple and have the feature of linear array, and estimated accuracy is higher, and engineer applied is comparatively extensive.

Fig. 4 is the structure chart of the inverted-L antenna array adopted in RSU equipment one embodiment of ETC system of the present invention.As shown in Figure 4, array element is along the symmetrical equidistant placement of two vertical lines (i.e. the configuration in vertical symmetry), and array element number is 11, and wherein 2D is the aperture between array element.In another embodiment, adopt 9 array elements and the configuration in vertical symmetry, for ensureing not occur that angle measurement is fuzzy, the aperture 2D (equidistantly) between the array element chosen is 0.5 λ, and wherein λ is the wavelength of microwave signal.It should be noted that, in the present invention, the array element number of inverted-L antenna array is not limited to 9 above-mentioned array elements or 11 array elements, and in other embodiments, array element number can be more or less.

Location Calculation module in the present invention mainly adopts the MUSIC algorithm in conjunction with front-rear space smooth technology, the direction of arrival of each signal source and interference source is estimated under relevant multi-path environment, thus extract the direction of arrival (DOA) of OBU exactly, lower mask body introduction adopts the MUSIC in conjunction with front-rear space smooth technology to calculate ratio juris:

One embodiment of the invention adopts 9 array elements to be vertical symmetry configuration, be horizontal stroke, vertical two M array elements (M=5) uniform line-array (ULA), array element distance d is λ/2, and λ is wavelength, antenna aperature D=(M-1) d, when the distance of label and antenna is greater than 2D ²during/λ, OBU signal can be considered to far-field signal, and its deflection arriving each array element regards as identical.If N (N<M) individual narrow band signal source s _i(t), (i=1,2 ..., N) (comprising the signal of OBU and each coherent interference information source), with linear array axis normal for reference, its information source direction was respectively θ with plane wave incidence in linear array ₁, θ ₂..., θ _n, θ _iexcursion is [-pi/2, pi/2].Array received signal phasor is:

X(k)＝A(θ)S(k)+Z(k) k＝1,2,...,K

In formula:

X(k)＝[x ₁(k),x ₂(k),...,x _M(k)] ^T

A(θ)＝[a(θ ₁),a(θ ₂),...,a(θ _N)]

a(θ _i)＝[1,exp(-jω _i),...,exp(-j(M-1)ω _i)] ^T

Z(k)＝[z ₁(k),z ₂(k),...,z _M(k)] ^T

In formula: ω _i=2 π dsin θ _i/ λ, λ are electromagnetic wavelength.S (k) is signal vector, and A (θ) is array manifold, a (θ _i) be the steering vector of i-th signal, Z (k) is noise vector, and the zero-mean irrelevant with signal source, variance are δ ²white Gaussian noise, k=1,2 ..., K, K are data sampling length.

According to the DOA Mathematical Modeling of signal source, the covariance matrix of its array data is:

R＝E[X(K)X ^H(K)]＝AR _SA ^H+δ ²I (1)

In formula: R _sthe covariance matrix of signal source, AR _sa ^hsignal section, δ ²i is noise section.

1) OBU number of source is estimated

In the application of actual track, OBU and multipath signal number be a unknown number often, and therefore source number estimation is a key issue.When the number of sources estimated and real number of source inconsistent time, false dismissal when can produce estimated signal source or false-alarm, also will cause the deviation when estimated signal direction (DOA).When signal source is concerned with, the method for estimation according to incoherent signal source judges that number of sources then cannot accurate estimated signal source number, more can not judge the classification of signal source and structure.Thus the embodiment of the present invention adopts two-way level and smooth order algorithm to judge OBU number and interference information source number, when meeting M>=J ₁when/2, (M is array number, J ₁relevant interference source number), adopt smoothing technique even linear array to be divided into the individual interlaced submatrix of P, thus construct juxtaposition matrix suppose that signal source is made up of the group of L group correlated source, be expressed as g _i(i=1,2 ..., L), if g ₂=3 explanations have 3 relevant groups, and every group has 2 coherent sources, and L is maximum correlated source number.If obtain data covariance matrix from the data of limited snap, now:

${\hat{R}}^{\left(P\right)}={\hat{R}}_0^{\left(P\right)}+{\mathrm{\&delta;}}^{2}I---\left(2\right)$

Be generalized to two-way level and smooth order algorithm, at this moment level and smooth order is classified as:

$\dim \left\{{\hat{R}}_0^{\left(P\right)}\right\}=\left\{\begin{array}{c}\underset{i=l}{\overset{L}{\mathrm{\&Sigma;}}}{g}_i,p=0\\ \min [M-p/2,\underset{i=l}{\overset{p}{\mathrm{\&Sigma;}}}{\mathrm{ig}}_i+(p+1)\underset{i=p+1}{\overset{L}{\mathrm{\&Sigma;}}}{g}_i],p\&GreaterEqual;1\end{array}\right.---\left(3\right)$

Can obtain according to minimum description length (MDL) criterion

$\dim \left\{{\hat{R}}^{\left(P\right)}\right\}=\underset{p=\mathrm{0,1},...,M-1}{\min }\mathrm{MDL}\left(P\right)---\left(4\right)$

Just can in the hope of the dependency structure of signal source and signal number N according to formula (1), formula (2);

2) front-rear space smooth algorithm

Search Space Smoothing is the more effective decorrelation LMS algorithm of current one, estimate to have desirable performance, and amount of calculation is very little to the DOA in coherent signal source, is convenient to realize.Its basic thought uniform line-array is divided into several equitant subarrays, if the array manifold of each subarray is identical, then subarray covariance matrix can be average.The vector of each submatrix is with respective first array element for benchmark, and because arrival bearing is different, the phase difference of two coherent signals is not identical in each array element, and namely space smoothing produces random phase modulation, thus can to the signal decorrelation causing order to wane.

The covariance matrix of the first pair array Received signal strength of the embodiment of the present invention carries out the preliminary treatment of front-rear space smooth, and recycling is revised rear result and carried out MUSIC Power estimation, thus realizes estimating the DOA of relevant label signal.

Preliminary treatment based on front-rear space smooth algorithm: the translation invariance utilizing uniform line-array, is evenly divided into P submatrix by array element from forward direction, and the array number of each subarray is m, by { 1,2 ..., m} forms the 1st subarray, and { 2,3 ..., m+1} forms the 2nd subarray, the like.In like manner, utilize the rotational invariance of uniform line-array, also divide P submatrix from backward by similar approach.Then forward and backward level and smooth revised data covariance matrix is respectively:

$R^f=\frac{1}{p}\underset{i=1}{\overset{p}{\mathrm{\&Sigma;}}}{F}_i\hat{R}{F_i}^H---\left(5\right)$

$R^b=\frac{1}{p}\underset{i=1}{\overset{p}{\mathrm{\&Sigma;}}}{Q}_i\hat{R}{Q_i}^H---\left(6\right)$

In formula: F _i=[0 _{mx (i-1)}| I _mxm| 0 _{mx (p-i)}], Q _i=[0 _{mx (i-1)}| J _mxm| 0 _{mx (p-i)}]; I _mxmfor permutation matrix, J _mxmfor back-diagonal is the matrix of 1.Carry out front-rear space smooth correction to the covariance matrix of the even linear array shown in formula (1) to obtain:

$R^{\mathrm{fb}}=1/2p(\underset{i=1}{\overset{p}{\mathrm{\&Sigma;}}}{F}_i\hat{R}{F_i}^H+\underset{i=1}{\overset{p}{\mathrm{\&Sigma;}}}{Q}_i{\hat{R}}^{*}{Q}_i^H)---\left(7\right)$

In formula: subscript * representing matrix conjugation, try to achieve the modified covariance method matrix R to R by formula (7) ^fb.Space smoothing algorithm is exactly the process recovered the order of the data covariance matrix of even linear array, thus reaches the object of decorrelation LMS.

To revised covariance matrix R ^fbcarry out Eigenvalues Decomposition to have

$R^{\mathrm{fb}}=U_S{\mathrm{\&Sigma;}}_S{U}_S^H+U_Z{\mathrm{\&Sigma;}}_Z{U}_Z^H---\left(8\right)$

In formula: U _sthe subspace of being opened by large characteristic value characteristic of correspondence vector also i.e. signal subspace, and U _zit is the subspace of being opened by little characteristic value characteristic of correspondence value characteristic of correspondence vector also i.e. noise subspace.Consider that actual reception data matrix is time-limited, data covariance matrix is:

${\mathrm{\&theta;}}_{\mathrm{MUSIC}}={\arg }_{\mathrm{\&theta;}}\min {\mathrm{\&alpha;}}^H\left(\mathrm{\&theta;}\right){\hat{U}}_Z{\hat{U}}_Z^H\mathrm{\&alpha;}\left(\mathrm{\&theta;}\right)---\left(9\right)$

The Power estimation formula of MUSIC algorithm is:

$P_{\mathrm{MUSIC}}=1/{\mathrm{\&alpha;}}^H\left(\mathrm{\&theta;}\right){\hat{U}}_Z{\hat{U}}_Z^H\mathrm{\&alpha;}\left(\mathrm{\&theta;}\right)---\left(10\right)$

When denominator gets minimum value in formula (10), will corresponding peak value be produced, thus angle θ can be reached to the ripple of signal by each spectrum peak _i(i=1,2 ..., N) add and make an estimate, wherein, (because the signal powers such as each relevant, interference information source are lower, corresponding peak value is less) that each spectrum coneincone value is higher, is azimuth and the angle of pitch of each OBU and positioner.

The method provided in the embodiment of the present invention can effectively solve under roadway environments complicated and changeable (there is the impact of relevant multi-path jamming) to the poor problem of the positioning precision of the vehicle that OBU is housed, and owing to accurately can locate current OBU, therefore, effectively can solve the interference problem between adjacent lane, achieve accurately deducting fees of no-stop charging system, and can realize the accurate location that OBU vehicle is housed in system such as freely flowing to city.

The present invention uses Dedicated Short Range Communications, technology (DSRC), by in roadside unit (RSU) the function class product of the spatial spectrum algorithm application of inverted-L antenna array and relevant super-resolution in electric non-stop toll (ETC) system, accurately can locate board units (OBU).The present invention is also applicable in the system of other application roadside unit.

Claims (9)

1. a RSU equipment for ETC system, comprises DSRC microwave antenna and read-write controller, it is characterized in that, described DSRC microwave antenna comprises:

Inverted-L antenna array, it comprises multiple microstrip antenna element, for transmitting and receiving OBU microwave signal, to carry out DSRC microwave communication with OBU equipment;

Multi-channel radio frequency receives/send out assembly, and for converting the microwave signal received by described array element to intermediate-freuqncy signal, the number of active lanes that assembly was received/sent out to wherein said multi-channel radio frequency is corresponding with the number of described array element, and each expanding channels array element;

Communication control module, for carry out DSRC communications protocol parsing and control described multi-channel radio frequency receive/send out assembly receive microwave signal;

Locating module, for adopting the spatial spectrum algorithm of super-resolution to determine the position of OBU according to described intermediate-freuqncy signal, and the positional information of described OBU is sent to described read-write controller, so that described read-write controller controls the read-write operation of described DSRC microwave antenna according to described positional information.

2. the RSU equipment of ETC system according to claim 1, is characterized in that, the spatial spectrum algorithm of described super-resolution comprises the combination of number of source algorithm for estimating, front-rear space smooth algorithm and MUSIC algorithm calculating.

3. the RSU equipment of ETC system according to claim 2, is characterized in that, described locating module comprises:

A/D acquisition module, receives for synchronous acquisition from described multi-channel radio frequency/sends out the intermediate-freuqncy signal of assembly, and carries out analog/digital conversion;

Digital Down Converter Module, for the intermediate-freuqncy signal after analog-to-digital conversion being carried out in-phase component and the quadrature component that Digital Down Convert process obtains signal, the digital signal of composition plural form;

Location Calculation module, for obtaining the positional information of OBU according to the digital signal of described plural form;

Base-Band Processing and communication control module, for processing described positional information, and give described read-write controller by the base band signal transmission comprising described positional information that obtains after process, and receive and to go forward side by side row relax from the read-write operation instruction of described read-write controller, and the Signal transmissions comprising described read-write operation instruction obtained after process to described multi-channel radio frequency is received/send out assembly.

4. the RSU equipment of ETC system according to claim 3, is characterized in that, described location Calculation module comprises:

Number of source estimation module, for adopting dependency structure and the information source number in two-way level and smooth order algorithm estimated signal source according to the digital signal of the plural form received;

Direction of arrival computing module, for adopting front-rear space smooth algorithm and MUSIC algorithm to calculate the direction of arrival of each information source according to the dependency structure of described signal source and information source number;

OBU location confirmation module, the spectrum peak for composing according to the MUSIC corresponding to each information source confirms the direction of arrival of OBU, and generates OBU positional information.

5. the RSU equipment of ETC system according to any one of claim 1 to 4, is characterized in that, assembly is received/sent out to described multi-channel radio frequency also for converting the departures intermediate-freuqncy signal comprised for sending information to microwave signal to be launched by described array element; Assembly launched microwave signal is received/sent out to described communication control module also for controlling described multi-channel radio frequency.

6. the RSU equipment of ETC system according to claim 5, is characterized in that, described communication control module comprises:

Protocol resolution module, for carrying out demodulation to described intermediate-freuqncy signal, thus carries out the parsing of DSRC communications protocol;

Receive path configuration module, carries out reception operation for the whole passages receiving/send out assembly in accepting state configuration multi-channel radio frequency;

Transmission channel configuration module, carries out firing operation at least one passage received/send out in emission state configuration multi-channel radio frequency in assembly.

7. the RSU equipment of ETC system according to any one of claim 1 to 4, is characterized in that, the array element number of described inverted-L antenna array is 9, and described array element is along the symmetrical equidistant placement of two vertical lines.

8. the RSU equipment of described ETC system according to claim 7, it is characterized in that, the aperture between described array element is 0.5 λ, and wherein λ is the wavelength of microwave signal.

9. the RSU equipment of described ETC system according to claim 5, is characterized in that,

The array element number of described inverted-L antenna array is 9, and described array element is 0.5 λ along the aperture between the symmetrical equidistant placement of two vertical lines, array element, and wherein λ is the wavelength of microwave signal.