WO2012151918A1

WO2012151918A1 - Method and device for positioning signal source

Info

Publication number: WO2012151918A1
Application number: PCT/CN2011/082485
Authority: WO
Inventors: 张恺; 曾祥希; 李延波; 马凯
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-07-20
Filing date: 2011-11-18
Publication date: 2012-11-15
Also published as: CN102890262A; CN102890262B

Abstract

Disclosed are a method and device for positioning a signal source. The method comprises the steps of: acquiring a reception signal power value of each receiver antenna when receiving a signal transmitted by a signal source; determining for each receiver antenna, respectively on the basis of each reception signal power value acquired, a probability value of when horizontal coordinates of the signal source are the horizontal coordinates of the receiver antenna; determining the horizontal coordinates of the signal source on the basis of each probability value determined. Employment of the technical solution of the present invention solves the problem in the prior art of heightened calculation complexity, reduced stability, great margin of error, and increased system costs.

Description

Source positioning method and device

The present invention relates to the field of communications technologies, and in particular, to a source positioning method and apparatus. Background technique

The free-flow system is a comprehensive intelligent transportation solution that combines modern technologies such as data communication technology, automatic control technology, computer network technology, and information release technology. The system can be used for urban congestion control and barrier-free charging for free driving.

The free-flow system can perform legality authentication and charging processing on the vehicle. In the prior art, a tag is set in the vehicle, and the license plate number information of the vehicle is stored in the tag. When the vehicle passes through the reader in the free-flow system, the reader can obtain The license plate number information in the tag, at the same time, the image capture device in the free stream system captures the license plate image of the vehicle, matches the captured license plate image with the license plate number information obtained by the reader, and if the match is successful, the vehicle is considered legal The vehicle, in turn, charges the vehicle, and if the match is unsuccessful, the vehicle is considered to be an illegal vehicle.

However, in the prior art, since the recognition rate of the license plate image captured by the image acquisition device is relatively low, the workload of the matching operation is huge, and more processing resources are consumed, and when the license plate image is matched with the license plate number information, The matching algorithm is more complicated.

In view of the above problems, the prior art proposes a location-based free flow system charging method. A label is set in the vehicle in advance, and the vehicle type information of the vehicle is stored in the label. When the vehicle passes through the reader in the free-flow system, the reader obtains the vehicle type information in the label, and obtains the position of the vehicle on a certain section of the road through the special equipment. At the same time, the free-flow system locates the lateral coordinates of the label on the vehicle, that is, determines the lateral position of the label on the vehicle, and then matches the position obtained by the dedicated device with the determined lateral position to obtain the position of the label and the actual position of the vehicle. Match As a result, legality authentication and charging processing are then performed based on the matching result and the model information. Among them, the prior art can realize accurate lateral positioning of the vehicle on a certain section of the road, such as a method using a laser grating.

A plurality of receiving antennas are deployed in advance on a certain section of the road. The label on the vehicle can be regarded as a signal source, that is, a source, and each receiving antenna receives a signal of the source. The prior art generally determines the vehicle by the following two methods. The lateral position of the label, specific:

In the first method, the received signal strength indication (RSI, Received Signal Strength Indication) of each receiving antenna is interpolated, and the function extremum is calculated according to the obtained function analytical expression, and the abscissa of the function extremum is used as the horizontal direction of the label. Location

In the second way, each receiving antenna is deployed intensively, with the position of the highest receiving antenna of the RSSI as the lateral position of the tag.

It can be seen from the above that the first method needs to perform interpolation operation, and also needs to calculate the extreme value of the function analytical expression, so the computational complexity is high, and the RSSI is greatly affected by the environment, so the stability is poor, and the error is large. The second method described above requires an increase in the number of receiving antennas, which undoubtedly increases system cost. Summary of the invention

The embodiment of the invention provides a method and a device for locating a source, which are used to solve the problems of high computational complexity, poor stability, large error and high system cost in the prior art.

The technical solutions of the embodiments of the present invention are as follows:

A method for locating a source, the method comprising: obtaining a received signal power value when each receiving antenna receives a signal sent by a source; and determining, for each receiving antenna, the source according to each obtained received signal power value The lateral coordinate is the probability value of the lateral coordinate of the receiving antenna; and the lateral coordinate of the source is determined according to the determined probability values.

A source locating device, comprising: a signal power value obtaining unit, configured to obtain a received signal power value when each receiving antenna receives a signal sent by a source; a probability value determining unit, configured to target Each receiving antenna respectively obtains a received signal power value obtained by the unit according to the signal power value, and determines a probability value when the lateral coordinate of the source is the lateral coordinate of the receiving antenna; and a coordinate determining unit, configured to determine according to the probability value Each probability value determined by the unit determines the lateral coordinate of the source.

The beneficial effects of the present invention are as follows:

In the technical solution of the embodiment of the present invention, first, obtain a received signal power value when each receiving antenna receives a signal sent by a source, and then, for each receiving antenna, determine a horizontal direction of the source according to each obtained received signal power value. The coordinate value is the probability value of the horizontal coordinate of the receiving antenna, and the lateral coordinate of the source is determined according to the determined probability values. Since the lateral coordinate of the source is closer to the lateral coordinate of the receiving antenna, the received signal power when the receiving antenna receives the signal is larger, and thus the lateral coordinate of the source can be determined by the received signal power value of the receiving antenna, which is implemented by the present invention. The technical solution is no longer based on the RSSI of each receiving antenna to determine the horizontal coordinate of the source, so there is no need to perform interpolation operations, and there is no need to calculate the extreme value of the function analytic, thereby reducing the computational complexity and improving the stability and positioning of the system. Accuracy, in addition, since the technical solution of the embodiment of the present invention does not need to increase the number of receiving antennas, system cost can be effectively saved. DRAWINGS

1 is a schematic flowchart of a source location method according to an embodiment of the present invention;

2 is a schematic diagram showing a positional relationship between a source and a receiving antenna in a free stream system according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a source locating device according to an embodiment of the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments in order to make the present invention. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. As shown in FIG. 1 , it is a flow chart of a source location method according to an embodiment of the present invention, and the specific processing procedure is as follows:

Step 11: Obtain a received signal power value when each receiving antenna receives a signal sent by the source. The receiving antenna provided by the embodiment of the present invention may be a directional antenna, and may also be an omnidirectional antenna. Taking the number of receiving antennas as five as an example, FIG. 2 is a schematic diagram of the positional relationship between the source and the receiving antenna in the free-flow system. Each receiving antenna is located on a section perpendicular to the road, and the distance between the source and the section is For L, the distance between two adjacent receiving antennas is b, and the lateral coordinates of receiving antennas 1~5 are A, X ₂ , ₃ , ₄ , X _{5 respectively} . If the lateral coordinate of receiving antenna 3 is 0, Bay ¹ JX =-lb, X ₂ =-b . ₃ = -0, X ₄ =b . X ₅ =2b , each antenna ό height value is h, the lateral coordinate of the vehicle is obtained by special equipment, k, on the vehicle The horizontal coordinate of the label (ie the source) is X. .

In the embodiment of the present invention, when the received signal power value of each receiving antenna is obtained, for each receiving antenna, the signal gain value and the signal attenuation value when the receiving antenna receives the signal sent by the source are first obtained, and then according to the obtained signal gain. The value and the signal attenuation value determine the received signal power value when the receiving antenna receives the signal transmitted by the source.

The signal gain of the receiving antenna is related to the angle value between the source and the receiving antenna. When obtaining the signal gain value of the receiving antenna, the angle value between the receiving antenna and the source is obtained first, and then the angle value is obtained according to the obtained angle value. And corresponding to the signal gain value, searching for the signal gain value corresponding to the obtained angle value, and determining the found signal gain value as the signal gain value when the receiving antenna receives the signal sent by the source.

Wherein, the angle value between the receiving antenna and the source can be obtained by, but not limited to, the following:

The value of the angle between the receiving antenna i and the source; the distance between the receiving antenna i and the source. As can be seen from Fig. 2, the distance between the receiving antenna i and the source can be obtained by:

/ _; = ^L ² + h ² + (X _i - kf

Obtaining the signal attenuation value when the receiving antenna receives the signal sent by the source, first obtaining the signal frequency value when the source transmits the signal and the distance value between the receiving antenna and the source, and then according to the obtained signal frequency value and the distance value And determining a signal attenuation value when the receiving antenna receives the signal sent by the source.

The signal attenuation value when the receiving antenna receives the signal transmitted by the source may be determined by, but not limited to, as follows:

D _i = 32.5 + 20 * log( ) + 20 * log(/ _; )

Wherein, _D; receiving the signal attenuation values for the transmitted source signal receive antenna i; / is the signal frequency value when a transmission signal source; _/; between receive antenna i with the source distance value.

After obtaining the signal gain value of the receiving antenna and the signal attenuation value, the received signal power value when the receiving antenna receives the signal transmitted by the source may be determined as follows:

U A)

Wherein, the received signal power value when the receiving antenna i receives the signal transmitted by the source; P. The value of the transmitted signal power when the signal is transmitted by the source; the signal gain value when the receiving antenna i receives the signal transmitted by the source; A is the signal attenuation value when the receiving antenna i receives the signal transmitted by the source.

Step 12: For each receiving antenna, determine a probability value when the lateral coordinate of the source is the lateral coordinate of the receiving antenna according to the obtained received signal power values.

When determining the probability value of the lateral coordinate of the source antenna as the lateral coordinate of the receiving antenna, the obtained received signal power value of the receiving antenna is first normalized, and then the value obtained by the normalization process is determined as The lateral coordinate of the source is the probability value of the lateral coordinate of the receiving antenna.

The determined received signal power value of the receiving antenna is normalized by: Where f is a value obtained by normalizing the received signal power value of the receiving antenna i; a received signal power value when the receiving antenna i receives the signal transmitted by the source; w is the number of receiving antennas.

Normalizing the received signal power value can achieve two effects. The first effect is that p can be removed by normalization. The second effect is that after the normalization process, the probability value of the lateral coordinate of the source is the lateral coordinate of each receiving antenna, and the received signal power value of each receiving antenna is regarded as a sample whole, and the receiving The signal power value may represent an overview of the source appearing at the corresponding position. Under such conditions, the horizontal coordinate of the source is the sum of the probability values of the lateral coordinates of each receiving antenna is 1, and the received signal power value of the receiving antenna is larger. , indicating that the lateral coordinate of the source is more likely to be the lateral coordinate of the receiving antenna.

Step 13: Determine the lateral coordinate of the source according to the determined probability values.

According to the direction of the receiving antenna and the attenuation characteristics of the wave in free space, the closer the source is to which receiving antenna, the stronger the signal received by the antenna, and the weaker the opposite, when the longitudinal coordinate of the source is constant, if it is determined When the horizontal coordinate of the source is the probability value of the lateral coordinates of each receiving antenna, it is known from the probability knowledge that the best estimate of the lateral coordinate of the source is the expected value of the lateral coordinate of the source, and thus can be derived from the horizontal coordinate of the source. The expected value is used to estimate the lateral coordinate of the source.

In the embodiment of the present invention, the horizontal coordinate of the source may be determined by, but not limited to, the following:

among them, . Is the horizontal coordinate of the source; , is the lateral coordinate of the receiving antenna i; ^ is the probability value of the horizontal coordinate of the source when receiving the lateral coordinate of the antenna i; w is the number of receiving antennas.

It has been proved by a large number of experiments that the positioning accuracy of the horizontal coordinate of the source of the embodiment of the present invention can be within 50 cm, and the positioning accuracy is very high.

The source location method proposed by the embodiment of the present invention is not only applicable to a source in a free stream system. Positioning with horizontal coordinates also applies to other systems that need to locate the lateral coordinates of the source. According to the foregoing processing, in the technical solution of the embodiment of the present invention, the received signal power value when each receiving antenna receives the signal sent by the source is first obtained, and then determined for each receiving antenna according to the obtained received signal power values. The lateral coordinate of the source is a probability value of the lateral coordinate of the receiving antenna, and the lateral coordinate of the source is determined according to the determined probability values. Since the lateral coordinate of the source is closer to the lateral coordinate of the receiving antenna, the received signal power when the receiving antenna receives the signal is larger, and thus the lateral coordinate of the source can be determined by the received signal power value of the receiving antenna, which is implemented by the present invention. The technical solution is no longer based on each receiving antenna

The RSSI determines the horizontal coordinate of the source, so there is no need to perform interpolation operations, and there is no need to calculate the extremum of the function analytic, thereby reducing the computational complexity, improving the system stability and the positioning accuracy, and further, due to the technology of the embodiment of the present invention. The solution does not need to increase the number of receiving antennas, so the system cost can be effectively saved.

A more detailed implementation is given below.

Let the number of receiving antennas be five, respectively R1 R2 R3 R4 R5, the height value of each receiving antenna h=6 m(m), the distance between two adjacent receiving antennas b=0.95 m, the lateral coordinate of the vehicle k=0.1 0.4 -0.1 or -0.4, L=7m or 9m

The distance between the source and each receiving antenna is shown in Table 1: 00

L=7 L=9

Rl R2 R3 R4 R5 Rl R2 R3 R4 R5

9.34 9.23 9.228 9.317 9.50 10.90 k=-0.

0770 5935 21759 85919 2105 05733 4

846 253 6 6 03 8

9.39 9.25 9.220 9.43 10.86 k=-0.

3614 8644 08676 3981 10.85 74974 11 1

853 609 7 9 132 3 7 1 k=0.1 9.43 9.27 9.220 9.258 9.39 11 10.86 10.81 10.85 10.965 II II 3981 9143 08676 64460 3614 74974 40013 oo

132 279 7 9 853 1

9.50 9.31 9.228 9.235 9.34 11.05 10.90 10.83

10.82 10.920 k=0.4 2105 7859 21759 93525 0770 84809 05733 06278

40473 16483 03 196 6 3 846 1 8 7 The signal attenuation values when the receiving antenna receives the signal from the source are shown in Table 1:

Table 2:

L=7 L=9

Rl R2 R3 R4 R5 Rl R2 R3 R4 R5

67.3 67.1 67.07 67.1 68.64 68.51 68.46

67.07 68.45 68.5331 2495 5488 81774 7621 24693 75467 1632

09164 n i o 63535 4375 64 274 7 423 2 3 55

67.2 67.2

67.1 67.06 67.09 68.59 68.49 68.4 68.4

624 252 68.5690 k=-0.1 1871 32600 95081 64135 11507 5078 7715

599 148 4955 749 3 5 7 8 966 463

4 7

67.2 67.1 67.06 67.09 67.2 68.59 68.49 68.45 68.47

68.5690 k=0.1 6245 1871 32600 95081 2521 64135 11507 07896 7154

4955 994 749 3 5 487 7 8 6 63

67.3 67.1 67.07 67.1 68.64 68.51 68.46

67.07 68.45 68.5331 k=0.4 2495 5488 81774 7621 24693 75467 1632

09164 63535 4375 64 274 7 423 2 3 55 The angle between the receiving antenna and the source is shown in Table 3:

table 3 :

L=7 L=9

Rl R2 R3 R4 R5 Rl R2 R3 R4 R5

9.240 3.41 2.48 8.330 2.117 12.00 92985 3983 4281 50780 83363 43039

The signal gain values when the receiving antenna receives the signal sent by the source are shown in Table 4: Table 4:

The difference between the signal gain value of the receiving antenna and the signal attenuation value is shown in Table 5: Table 5:

L=7 L=9

The lateral coordinates and errors of the identified sources are shown in Table 7: Table 7:

It can be seen from the above that when the source positioning method proposed by the embodiment of the present invention locates the horizontal coordinate of the source, the error is less than 15 cm, and the precision is very high.

Correspondingly, the embodiment of the present invention further provides a source locating device, and the structure thereof is as shown in FIG. 3, including:

The signal power value obtaining unit 31 is configured to obtain a received signal power value when each receiving antenna receives the signal sent by the source;

The probability value determining unit 32 is configured to obtain, for each receiving antenna, a power value of each received signal obtained by the unit 31 according to the signal power value, and determine a probability value when the horizontal coordinate of the source is the horizontal coordinate of the receiving antenna;

The coordinate determining unit 33 is configured to determine the lateral coordinates of the source according to the probability values determined by the probability value determining unit 32.

Preferably, the signal power value obtaining unit 31 specifically includes:

a gain value obtaining sub-unit, configured to obtain, for each receiving antenna, a signal gain value when the receiving antenna receives the signal sent by the source;

The attenuation value obtaining sub-unit is configured to obtain, for each receiving antenna, a signal attenuation value when the receiving antenna receives the signal sent by the source, respectively;

a signal power value obtaining sub-unit for obtaining, for each receiving antenna, according to a gain value The signal gain value obtained by the subunit and the attenuation value obtain the signal attenuation value obtained by the subunit, and determine the received signal power value when the receiving antenna receives the signal sent by the source.

More preferably, the gain value obtaining subunit specifically includes:

An angle value obtaining module, configured to obtain, respectively, an angle value between the receiving antenna and the source for each receiving antenna;

a gain value finding module, configured to obtain an angle value obtained by the module according to the angle value for each receiving antenna, and find a signal gain value corresponding to the obtained angle value in a correspondence between the angle value and the signal gain value;

The gain value determining module is configured to determine, for each receiving antenna, a signal gain value found by the gain value finding module, respectively, as a signal gain value when the receiving antenna receives the signal sent by the source.

More preferably, the attenuation value obtaining subunit specifically includes:

a frequency value obtaining module, configured to obtain, respectively, a signal frequency value when the source transmits a signal for each receiving antenna;

a distance obtaining module, configured to obtain, respectively, a distance value between the receiving antenna and the source for each receiving antenna;

The attenuation value determining module is configured to obtain, according to the frequency value, a signal frequency value obtained by the module and a distance value obtained by the distance value obtaining module for each receiving antenna, and determine a signal attenuation value when the receiving antenna receives the signal sent by the source.

Preferably, the probability value determining unit 32 specifically includes:

a normalization processing sub-unit, configured to normalize the received signal power value of the receiving antenna obtained by the signal power value obtaining unit 31 for each receiving antenna;

a probability value determining subunit, configured to normalize the value obtained by normalizing the normalized processing subunit for each receiving antenna, and determine the probability value when the horizontal coordinate of the source is the lateral coordinate of the receiving antenna . The above description shows and describes a preferred embodiment of the present invention, but as described above, it should be understood that the present invention is not limited to the forms disclosed herein, and should not be construed as Other combinations, modifications, and environments are possible and can be modified by the teachings or related art or knowledge within the scope of the inventive concept described herein. All changes and modifications made by those skilled in the art are intended to be within the scope of the appended claims.

Claims

Claim

A method for locating a source, characterized in that it comprises:

Obtaining a received signal power value when each receiving antenna receives a signal transmitted by the source;

For each receiving antenna, determining a probability value when the lateral coordinate of the source is the lateral coordinate of the receiving antenna according to the obtained received signal power values respectively;

The lateral coordinates of the source are determined according to the determined probability values.

The method according to claim 1, wherein the received signal power value when each receiving antenna receives the signal sent by the source includes:

For each receive antenna, perform separately:

Obtaining a signal gain value and a signal attenuation value when the receiving antenna receives the signal sent by the source;

And determining a received signal power value when the receiving antenna receives the signal sent by the source according to the obtained signal gain value and the signal attenuation value.

The method according to claim 2, wherein the obtaining a signal gain value when the receiving antenna receives the signal sent by the source comprises:

Obtaining an angle value between the receiving antenna and the source;

Obtaining, according to the obtained angle value, a signal gain value corresponding to the obtained angle value in a correspondence relationship between the angle value and the signal gain value;

The found signal gain value is determined as the signal gain value when the receiving antenna receives the signal sent by the source.

The method according to claim 2, wherein the obtaining a signal attenuation value when the receiving antenna receives the signal sent by the source comprises:

Obtaining a signal frequency value when the source transmits the signal and a distance value between the receiving antenna and the source;

Determining, according to the obtained signal frequency value and the distance value, the signal sent by the receiving antenna to receive the source Signal attenuation value at time.

5. The method according to claim 4, wherein the signal attenuation value when the receiving antenna receives the signal transmitted by the source is determined by:

D. = 32.5 + 20 * log( ) + 20 * log(/. )

Wherein, the signal attenuation value when the receiving antenna i receives the signal sent by the source;

/ signal frequency value when transmitting a signal to the source;

To receive the distance between the antenna i and the source.

6. The method according to claim 2, wherein the received signal power value when the receiving antenna receives the signal transmitted by the source is determined by:

U A)

Wherein, the received signal power value when the receiving antenna i receives the signal sent by the source;

P ₀ is the transmitted signal power value when the signal is transmitted by the source;

(^ is the signal gain value when the receiving antenna i receives the signal transmitted by the source;

The signal attenuation value when the receiving antenna i receives the signal transmitted by the source.

The method according to claim 1, wherein determining a probability value when the horizontal coordinate of the source is the lateral coordinate of the receiving antenna comprises:

And normalizing the obtained received signal power value of the receiving antenna;

The value obtained after the normalization process is determined as the probability value when the lateral coordinate of the source is the lateral coordinate of the receiving antenna.

8. The method according to claim 7, wherein the determined received signal power value of the receiving antenna is normalized by:

Wherein, a value obtained by normalizing the received signal power value of the receiving antenna i; Pi is a received signal power value when the receiving antenna i receives the signal transmitted by the source;

W is the number of receiving antennas.

9. The method of claim 1 wherein the lateral coordinate of the source is determined by: i = l

Among them, X. Is the horizontal coordinate of the source;

, is the lateral coordinate of the receiving antenna i;

The lateral coordinate of the source is the probability value when receiving the lateral coordinate of the antenna i;

w is the number of receiving antennas.

10. A source location device, comprising:

a signal power value obtaining unit, configured to obtain a received signal power value when each receiving antenna receives a signal sent by the source;

a probability value determining unit, configured to obtain, for each receiving antenna, a received signal power value obtained by the unit according to the signal power value, and determine a probability value when the horizontal coordinate of the source is the horizontal coordinate of the receiving antenna;

And a coordinate determining unit, configured to determine, according to each probability value determined by the probability value determining unit, a lateral coordinate of the source.

11. The apparatus according to claim 10, wherein the signal power value obtaining unit comprises:

a signal power value obtaining sub-unit, configured to obtain, according to the gain value, a signal gain value obtained by the sub-unit and an attenuation value according to the gain value, respectively, to obtain a signal attenuation value obtained by the sub-unit, The received signal power value when the receiving antenna receives the signal transmitted by the source.

The apparatus according to claim 11, wherein the gain value obtaining subunit specifically comprises:

The method according to claim 11, wherein the obtaining the sub-unit of the attenuation value comprises:

The method according to claim 10, wherein the probability value determining unit specifically comprises:

a normalization processing sub-unit, configured to normalize the received signal power value of the receiving antenna obtained by the signal power value obtaining unit for each receiving antenna;

a probability value determining subunit for respectively normalizing the processing sub-sheet for each receiving antenna The value obtained by the normalization process is determined as the probability value when the lateral coordinate of the source is the lateral coordinate of the receiving antenna.