KR20000014751A - Method for tracking a location of a mobile/personal portable communication system using a grid - Google Patents

Abstract

PURPOSE: A location tracking method is provided to obtain desired terminal information more exactly and finely to be capable of tracking a location without mounting a global positioning system. CONSTITUTION: The method for tracking a location of a mobile/personal portable communication system without using a global positioning system comprises the steps of: dividing a service area into blocks by a grid of a predetermined size in order to increase a location confirmation accuracy of the communication system; performing a terminal data logging at each divided position; analyzing the terminal logging data of a point representative of each divided point; and constructing a database by analyzing the terminal logging data of a point representative of each divided point.

Description

Location Tracking Method of Mobile / Personal Communication System Using Grid

The present invention relates to a system for tracking the position of a terminal for a mobile communication system or a personal portable communication system without using a global positioning system (GPS). In particular, the present invention relates to a method of obtaining information necessary for tracking a location of a terminal for a mobile communication system or a personal portable communication system using an existing network without using GPS.

Terminal location tracking in a conventional mobile communication system or personal digital communication system has been implemented in four ways as described below.

In the first method of the related art, as illustrated in FIG. 1, the directions 104, 105, and 106 of receiving a signal of a terminal from a plurality of base stations 101, 102, and 103 are measured, and the direction measured from the base station is straight. After connecting to each other, the intersection 107 of several straight lines is found. This method is called Angle of Arrival (AOA). In the AOA method, the beam width of the antenna used in the base station should be very small in order to accurately measure the position of the terminal.

However, in the urban environment, the signal transmitted from the terminal to the base station is reflected by a plurality of reflectors, so that the direction of the radio wave is changed irregularly. As a result, the location tracking of the terminal using the AOA has a disadvantage in that there is a large error in a region with many reflectors.

The second method of the prior art is a method of using a time of arrival (TOA) by using the electromagnetic wave transmission time delays 204, 205, and 206 between the terminal 210 and the base stations 201, 202, and 203, as shown in FIG. ). In this method, electromagnetic wave transmission time delays 204, 205, and 206 between a terminal and a plurality of base stations 201, 202, and 203 are measured, and the distances 204, 205, and 206 between the terminal and each base station are measured using the measured information. Calculate The calculated distances are used to find the circles 207, 208, and 209 around each base station and find the intersections of the circles 210.

However, this method also measures longer than the actual distance due to the reflection of the signal in areas where there are many reflectors such as urban environment. Therefore, there has been a problem that shows a large error in the position measurement of the terminal.

The third method of the related art is a method similar to the above-described TOA as shown in FIG. 3, instead of directly measuring the electromagnetic wave transmission time delay between the base stations 301, 302, 303, 304 and the terminal 308. It is called TDOA (Time Difference of Arrival) as a method of finding a location of a terminal by measuring a relative distance from other base stations 302, 303, 304 based on the distance between one base station 301. In this case, the method of finding the location of the terminal finds the hyperbolas 305, 306, and 307 connecting the points having a constant distance with respect to the base station 301 and other base stations 302, 303, and 304 as reference. Find the intersection 308 of several hyperbolas.

However, this method also has a problem that it is difficult to measure the exact position of the terminal when the reflector on the propagation path between the base station and the terminal, as in the above TOA is measured longer than the actual distance.

The fourth method of the prior art is a method of finding a location using GPS as shown in FIG. That is, the GPS receiver is embedded in the terminal to track the position of the terminal 405. GPS utilizes 24 satellites 401, 402, 403, and 404 moving around the earth to find the position of a receiver at any position on the earth. GPS continuously transmits the current GPS position and accurate time. In GPS, data is transmitted as a spread spectrum signal by a pseudo noise signal. The reason for using the spread spectrum signal is to overcome the electromagnetic loss between the satellite and the terrestrial receiver and to use the autocorrelation characteristic of the virtual noise signal.

In the case of the virtual noise signal, as shown in FIG. 5, the received signal is demodulated only when the phases of the two signals generated in the receiver and the signals 406, 407, 408, and 409 are exactly matched (501). Thus, using this property, it is possible to measure the electromagnetic wave propagation time delay between the receiver and the transmitter.

Two kinds of virtual noise signals used in GPS are used. One is a C / A code with a speed of 1.023 Mbps for civilian use and the other is a P code with a speed of 10.23 Mbps. When the C / A code is used, the measurement error is 200 to 300 m, and when the P code is used, the measurement error is 20 to 30 m. Therefore, when performing the location tracking of the terminal using the C / A code used for civil purposes, the error of the position measurement is 200 ~ 300 m.

The method developed to reduce this error is DGPS (Differential GPS). As shown in FIG. 6, in the DGPS, a reference station 605 is added to the GPS system. The reference station 605 is a base station that is easy to receive GPS satellite signals 611, 612, 613, 614 and knows the exact latitude and longitude, and transmits an error 607 of position information received from the GPS satellites to an adjacent GPS receiver. Play a role. In this case, when the position of the reference station and the GPS receiver is far from each other, error correction is not accurately performed. Therefore, the reference station should be located at regular intervals for correct positional correction.

When using DGPS, the error of location tracking depends on the distance between the terminal and the reference station. When the distance between the terminal and the reference station is far, the location tracking error is large. On the contrary, when the distance between the terminal and the reference station is close, the location tracking error is relatively small. In addition, the location conditions of the reference station required when using the DGPS can receive the signals of all the satellites received by the terminals of the service area, the area should be smooth communication with the terminal. Therefore, when performing location tracking using DGPS, it is difficult to satisfy all of the above-described location conditions of the reference station. In addition, when using GPS, there is a problem that the initial signal acquisition time of the GPS receiver is long.

The biggest problem of the location tracking method using GPS is that it is impossible to implement a small GPS that can be mounted on the terminal.

It is a first object of the present invention to propose a method which can overcome the disadvantages of all the above mentioned methods and obtain a high position tracking hit rate.

It is a second object of the present invention to provide a method for more accurately and precisely obtaining terminal information necessary for enabling location tracking of a terminal without mounting a GPS device.

1 is a diagram illustrating a terminal location search using an Angle of Arrival (AOA).

2 is a diagram illustrating a terminal location search using a time of argument (TOA).

3 is a diagram illustrating a terminal location search using a time difference of arrival (TDOA).

4 is a diagram illustrating location search using a global positioning system (GPS).

5 is a diagram illustrating autocorrelation of a virtual noise signal.

6 is a diagram illustrating a terminal location search in the case of using differential GPS (DGPS).

7 is an arbitrary spacing grid division diagram.

8 illustrates a virtual grid generated due to grid division.

9 is a grid subdivision diagram for an area having difficulty in determining terminal location.

10 is a terminal location mapping diagram according to the present invention.

<Explanation of symbols for main parts of drawing>

101, 102, 103, 201, 202, 203, 301, 302, 303, 304: base station

104, 105, 106: direction of terminal signals measured at the base station

204, 205, 206: distance between the base station and the terminal

207, 208, 209, 305, 306, 307: the location where the terminal can exist

107, 210, 308, 405, 608: Mobile station

601, 602, 603, 604, 401, 402, 403, 404: GPS satellites

611, 612, 613, 614, 406, 407, 408, 409: GPS satellite signal

501: Autocorrelation of virtual noise signal with time deviation of 0

605: reference station

607, 610: GPS satellite error

606, 609: latitude and longitude measured by GPS

615: GPS satellite error transmission link

701, 702, 703, 704, 705, 706, 707, 708, 709, 710, 711, 712, 713, 714, 715, 716, 801, 802, 803, 804, 805, 806, 807, 808, 809, 810, 811, 812, 813, 814, 815, 816, 901, 902, 903, 904, 905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 915, 916, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015, 1016: DB (DataBase) creation reference point

717: blocks separated by arbitrary distance

817: Virtual point mapping area generated by the block

917, 918, 919, 920, 921: Subdivided DB creation reference point

922: virtual point mapping region generated by the subdivided block

1017: Terminal location area mapped to point 1004

The present invention relates to a method for tracking the location of a mobile / personal communication system without using GPS, by using a grid of any size in order to increase the positioning accuracy of the mobile / personal communication system. Dividing a service area into blocks, executing terminal data logging at each of the separated points, and analyzing terminal input data of the points representing the separated points; And, characterized in that it comprises the step of building a DB by analyzing the terminal input data of the point representing each of the divided points.

In addition, the present invention provides a method for analyzing data obtained from a mobile communication / personal communication system, applying a weight to each comparison data, and determining a location of the mobile communication / personal communication system. And further performing a comparison with the stored DB.

The invention further comprises the steps of modifying the software on the mobile / personal communication system and analyzing the data received from the mobile / personal communication system at the location tracking center.

Other objects, advantages and details of the invention will be described in detail below with reference to the accompanying drawings.

7 is a grid subdivision of arbitrary spacing. A feature of the present invention is that a point on a block divided by an arbitrary distance is used as a reference point as shown in FIG. 7 without installing a separate base station. In order to configure the reference point, the size of the block should be set according to the characteristics of the region, and the information of the base stations received by the terminal at the point corresponding to each reference point should be made into a database (DB). In order to increase the terminal tracking rate, it is necessary to analyze the pattern of the base station information obtained at each reference point and adjust the position of the reference point to have a convenient pattern for tracking the location of the terminal. The mobile terminal transmits the information from all the base stations it can receive to the location tracking center, and the location tracking center patterns the information from the received terminal and compares the data with the data in the DB. Mapping locations

Hereinafter, an operation of a preferred embodiment of the present invention will be described with reference to FIG. 10, which shows the method for mapping a terminal location of the present invention. First, the position of any reference point, as indicated by reference numerals 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015, 1016, etc. Set it. In order to provide a higher terminal location hit rate, the set reference point needs to be adjusted to a location that can be characterized by a pattern of information received from neighboring base stations at each location in order to distinguish it from other reference points. . In addition, depending on the region, it may be necessary to add a reference point as shown in FIG. Once the reference point is determined, terminal data logging for as long as possible is required to extract more stable patterns at each location. It is also possible to install the terminal at the location of the reference point in order to build a DB which is less affected by changes in weather conditions, surroundings and communication network conditions.

At the time of attempting to track the location of the mobile terminal, it is also possible to collect data from the terminal on the reference point to generate an active pattern for the base station data from the terminal to track the location of the mobile terminal. Basic data necessary for DB construction of a reference point is generated based on terminal logging data at the corresponding position. Based on the input data collected at each point, we build a DB for each point. Location tracking of the mobile terminal begins with analyzing the terminal information transmitted from the mobile terminal to the location tracking center. The data received from the mobile terminal is analyzed and converted into a format that is easy to search on the DB of the location tracking center. The data from the mobile terminal thus converted is compared with the DB of the location tracking center to find a reference point having the most similar pattern. As shown in FIG. 10, the searched mobile terminal positions are located within the allowable error range by mapping the positions of all mobile terminals existing in the reference numeral 1017 area to the reference reference numeral 1004. Make it possible to identify the location.

While certain embodiments of the invention have been described in a manner that illustrates the invention, those skilled in the art will recognize that the invention includes all modifications and equivalents included in the claims.

Using the present invention, it is possible to establish a terminal location tracking system without having to spend a lot of money for terminal location tracking. In addition, using the method of the present invention, the accuracy of terminal location tracking can be much improved compared to the conventional terminal location tracking method.

Claims (3)

A method for tracking the location of a mobile / personal communication system without using GPS, a) dividing the service area into blocks by a grid of any size to increase the positioning accuracy of the mobile / personal communication system; b) executing terminal data logging at each of the separated points; c) analyzing terminal input data (logging data) of a point representing each of the separated points; d) analyzing a terminal input data of a point representing each of the separated points to build a DB. 2. The location tracking center of claim 1, further comprising: analyzing data obtained from a mobile / personal communication system, applying weights to respective comparison data, and identifying a location of the mobile / personal communication system; And further performing a comparison with a DB stored in the location tracking method. 3. The method of claim 2, further comprising modifying software on a mobile / personal communication system and analyzing data received from the mobile / personal communication system at a location tracking center. Location tracking method.