KR102239506B1 - Reliable precise ranging method and program for performing the analysis - Google Patents

Abstract

The present invention provides a stable high-precision distance measurement method of a mobile terminal, which comprises: an environment factor generation step of determining an environment factor reflecting a multi-path environment of a mobile terminal based on an operation installation map; a high-precision CSI correction value calculation step in which the mobile terminal calculates a high-precision CSI correction value using the CSI measurement value; and a step of generating, by the mobile terminal, a high-precision distance estimate value using the high-precision CSI correction value to generate a high-precision distance estimate value.

Description

Stable high-precision distance measurement method of mobile terminal and recording medium recording a program to perform it {RELIABLE PRECISE RANGING METHOD AND PROGRAM FOR PERFORMING THE ANALYSIS}

The present invention relates to a positioning technology for measuring the position of a mobile terminal indoors. More specifically, when measuring the position of a mobile terminal indoors, a more stable and high-precision position measurement is possible by using an environmental factor that reflects multiple paths. The present invention relates to a method for measuring a stable, high-precision distance of a mobile terminal that makes it possible and a recording medium recording a program for performing the same.

In general, a mobile terminal measures its location outdoors by using a GPS satellite signal. In an outdoor environment where a GPS satellite signal can be received smoothly, the location accuracy is stable within several meters. However, in an urban environment in which tall buildings are concentrated, the number of available GPS satellites is limited, and the calculated location accuracy is rapidly lowered. To solve this problem, a fusion positioning method with Map Matching or DR (Dead Reckoning), a kind of inertial navigation, is used.

In the case of indoors where the mobile terminal cannot receive GPS satellite signals, an active positioning method that establishes a location-dedicated network and determines its location by interlocking with it, and a passive type that obtains location information using additional functions of the existing communication network. The position of the mobile terminal can be measured by selectively applying a passive positioning method.

In general, in an indoor positioning environment of a mobile terminal, a passive positioning method is prioritized in consideration of cost and interworking with a communication network. In this case, the mobile terminal determines the location by triangulation or electronic fingerprinting. In the case of determining the location by triangulation, the mobile terminal uses Received Signal Strength (RSS) or reception status information (Channel Status Indicator, hereinafter CSI), which is additional information of the air interface of the wireless communication network (e.g., WiFi). Perform distance measurement.

However, RSS, which is used as a universal measurement value, not only has a bi-modal statistical distribution characteristic, but also has a problem of generating location information with a larger error in an indoor environment where multi-paths occur.

The technical problem to be solved by the present invention is a movement that enables more stable and high-precision position measurement by using environmental factors reflecting multi-paths when measuring the position of a mobile terminal in an indoor environment where GPS satellite signals cannot be received. It is to provide a stable high-precision distance measurement method of a terminal and a recording medium recording a program for performing it.

An aspect of the present invention is an environment factor generation step of determining an environment factor reflecting a multipath environment of a mobile terminal based on an operation and installation map; A high-precision CSI correction value calculation step in which the mobile terminal calculates a high-precision CSI correction value by using a CSI (Channel Status Indicator) measurement value, and a high-precision distance estimate generation step in which the mobile terminal generates a high-precision distance estimate value using the high-precision CSI correction value. can do.

)를 다음의 [수학식]에 따라 결정할 수 있다.In addition, the environmental factor (

) Can be determined according to the following [Equation].

In addition, the high-precision CSI correction value CSId may be determined according to the following [Equation].

In addition, the high-precision distance estimation value (d) may be determined according to the following [Equation].

Another aspect of the present invention may be a computer-readable recording medium in which a computer program is recorded for performing a stable high-precision distance measurement method of a mobile terminal according to any one of claims 1 to 4.

According to one aspect of the present invention described above, a method for measuring a stable high-precision distance of a mobile terminal and a recording medium recording a program for performing the same are provided, but the CSI-based distance estimation method having strong characteristics in a multi-path environment is provided for each indoor environment. By dividing the degree of multi-path occurrence into open, semi-open, and complex environments using an indoor map and reflecting it as an environmental factor of the CSI measurement, it is possible to reliably estimate high-precision distance indoors, and accordingly, the indoor location using CSI. Estimation precision is dramatically improved.

1 is a schematic diagram of a positioning system to which a stable high-precision distance measurement method of a mobile terminal according to an embodiment of the present invention is applied.
2 is a flowchart of a method for measuring a stable high-precision distance of a mobile terminal according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The detailed description of the present invention described below refers to the accompanying drawings, which illustrate specific embodiments in which the present invention may be practiced. These embodiments are described in detail sufficient to enable a person skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different from each other, but need not be mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the present invention in connection with one embodiment. In addition, it should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the detailed description to be described below is not intended to be taken in a limiting sense, and the scope of the present invention, if appropriately described, is limited only by the appended claims, along with all ranges equivalent to those claimed by the claims. Like reference numerals in the drawings refer to the same or similar functions over several aspects.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

1 is a schematic diagram of a positioning system to which a stable high-precision distance measurement method of a mobile terminal according to an embodiment of the present invention is applied.

The positioning system to which the present invention is applied may include an access point (AP) 110, a WiFi module 120, and a control unit 130.

The WiFi module 120 communicates with the AP 110 using WiFi and performs a location measurement of the mobile terminal together with the control unit 130.

The controller 130 may calculate a high-precision CSI correction value based on the CSI measurement value corresponding to the channel state information.

In addition, a high-precision distance estimate may be generated using the high-precision CSI correction value. Here, the CSI measurement is channel state information measured by the mobile terminal based on a signal (or information) received from the AP 110.

At this time, the controller 130 may derive a high-precision distance estimate using the CSI measurement value and then calculate the location of the mobile terminal using a triangulation method with three or more APs 110. In addition, the location calculated as described above can be displayed and provided on the indoor map information.

Meanwhile, the controller 130 may acquire indoor map information for indoor positioning. In addition, if it is provided after checking whether the RF fingerprint (FingerPrint) DB is provided, the DB can be obtained.

In this case, the control unit 130 may perform pattern matching on an RF fingerprint (FingerPrint) DB by using the high-precision CSI correction value. Accordingly, when pattern matching is performed, the mobile terminal can detect the corresponding location information on the RF fingerprint (FingerPrint) DB. In addition, corresponding location information may be displayed and provided on the indoor map information.

2 is a flowchart of a method for measuring a stable high-precision distance of a mobile terminal according to an embodiment of the present invention.

The stable high-precision distance measurement method of a mobile terminal according to an embodiment uses the step of generating an environmental factor reflecting multiple paths (S210), calculating a high-precision CSI correction value based on the CSI measurement value (S220), and the high-precision CSI correction value. It may include generating a high-precision distance estimate (S230).

)를 운용 설치 맵(Map)을 기반으로 다음의 [수학식 1]에따라 결정한다. Environment factor generation step (S210) is an environment factor reflecting the multi-path environment of the mobile terminal (

) Is determined according to the following [Equation 1] based on the operation and installation map.

는 사용되는 무선네트워크 특성에 따라 결정된(Fixed) 인자로서 송수신 RF 밴드의 이득과 안테나 이득을 나타낸다.

는 운용되는 실내환경에 따라 가변되는(Variable) 인자로서 거리측정 시스템이 운용되는 실내 Map기반으로 개방형(open), 반개방형(half open), 복잡환경(closed) 구분된 후 환경 인자(

,

,

)가 추출된다. here,

Denotes the gain of the transmit/receive RF band and the antenna gain as a factor fixed according to the characteristics of the wireless network used.

Is a variable (Variable) factor depending on the indoor environment in which the distance measurement system is operated, and is divided into open, half open, and closed environments based on the indoor map in which the distance measurement system is operated, and then the environmental factor (

,

,

) Is extracted.

In the step of calculating the high-precision CSI correction value (S220), the mobile terminal calculates a high-precision CSI correction value (CSId) according to the following [Equation 2] by using the CSI measurement value.

는 중심 주파수,

는 k 번째 서브캐리어 주파수,

는 k 번째 서브캐리어의 CSI 크기의 절대값(Amplitude)이다.here,

Is the center frequency,

Is the k-th subcarrier frequency,

Is the absolute value of the CSI size of the k-th subcarrier.

In the step of generating a high-precision distance estimate (S230), the mobile terminal generates a high-precision distance estimate according to the following [Equation 3] by using the high-precision CSI correction value (CSId) calculated in the correction-value calculation step (S220).

는 빛의 속도(300,000km/s),

은 전파경로 환경에 따른 경로감쇄인자로서 다중경로가 거의 없는 개방형 실내공간에서는 1에 가까운 값을 갖고, 복도 환경과 같은 반개방형 실내에서는 2에 가까운 값을 갖으며, 복잡한 실내환경에서는 4 이상의 값을 갖는다.here,

Is the speed of light (300,000 km/s),

Is a path attenuation factor according to the propagation path environment, and has a value close to 1 in an open indoor space with few multipaths, close to 2 in a semi-open indoor space such as a corridor environment, and a value of 4 or more in a complex indoor environment. Have.

Such a stable, high-precision distance measurement method of a mobile terminal can be implemented as an application or implemented in the form of program instructions that can be executed through various computer components, and recorded in a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, and the like alone or in combination.

The program instructions recorded in the computer-readable recording medium may be specially designed and constructed for the present invention, and may be known and usable to those skilled in the computer software field.

Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, magnetic-optical media such as floptical disks. media), and a hardware device specially configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the processing according to the present invention, and vice versa.

Although the above has been described with reference to embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention described in the following claims. I will be able to.

110: access point
120: WiFi module
130: control unit

Claims (5)

An environment factor generation step of determining an environment factor reflecting the multi-path environment of the mobile terminal based on an operation and installation map;
The step of calculating a high-precision CSI correction value in which the mobile terminal calculates a high-precision CSI correction value using a channel status indicator (CSI) measurement value, and
And generating a high-precision distance estimate, in which the mobile terminal generates a high-precision distance estimate by using the high-precision CSI correction value,
The above environmental factors (

) Is determined according to the following [Equation],

,

(here,

Denotes the gain of the transmit/receive RF band and the antenna gain as a factor fixed according to the characteristics of the wireless network used.

Is a variable (Variable) factor depending on the indoor environment in which the distance measurement system is operated.

), semi-open type (

), complex environment (

), and then the environmental factors are extracted. )
The high-precision CSI correction value ( CSId ) is determined according to the following [Equation],

(here,

Is the center frequency,

Is the k-th subcarrier frequency,

Is the absolute value of the CSI size of the k-th subcarrier.)
The high-precision distance estimation value (d) is a stable high-precision distance measurement method of the mobile terminal determined according to the following [Equation].

(here,

Is the speed of light (300,000 km/s),

Is a path attenuation factor according to the propagation path environment, and has a value close to 1 in open indoor spaces with few multipaths, close to 2 in semi-open indoor spaces such as corridor environments, and more than 4 in complex indoor environments. Have.)
delete delete delete A computer-readable recording medium on which a computer program is recorded for performing the method of measuring a stable, high-precision distance of a mobile terminal according to claim 1.

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