KR20020093547A - Wireless positioning method for in-building using the delay - Google Patents

Abstract

PURPOSE: A method for measuring a position of a motion body for an in-building service using a delay element is provided to embody a function for tracing the position of a subscriber in the in-building service by installing the time delay element between a remote unit and an antenna, differently setting a delay time per the antenna, and discriminating a servicing antenna using the delay time in a BTS(Base station Transceiver Subsystem). CONSTITUTION: Delay elements(15a-15n) are installed at antenna sides installed in a servicing area in a building, and delay times of the delay elements(15a-15n) are differently set according to antennas. A BTS(12) calculates an RTD(Round Trip Delay) in which a BTS signal is transmitted to an MS(Mobile Station) and is fed back gain. The BTS compares a predetermined delay time value of an antenna with the RTD, discriminates an antenna which services the MS, and grasps a position of the MS. The delay elements(15a-15n) are installed between remote units(14a-14n) and the antennas so that the degree of the delay times is differently set according to the antennas and the delay time values are set in a maximum long interval according to the antennas in consideration of an error of the RTD value received from the MS.

Description

Wireless positioning method for in-building using the delay}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of mobile positioning technology in wireless communication systems, and more particularly to a mobile positioning method using time delay for in-building services, and a computer readable recording medium having recorded thereon a program for realizing the method. It is about.

Here, the wireless communication system is a Code Division Multiple Access (CDMA) mobile communication system, a personal mobile communication system (PCS), a wireless data communication system, and IMT- which is currently being standardized in North American and European methods. The term includes a next generation mobile communication system such as 2000 (International Mobile Telecommunication), UMTS (Universal Mobile Telecommunication Service), and a frequency common communication system.

In general, mobile positioning technology can be classified into the following network-based, terminal-based, dedicated network-based, other technologies.

Looking at the general mobile positioning technology to help the understanding of the present invention is as follows.

First of all, the network-based technology is a method of determining a location using a base station transceiver subsystem (BTS) constituting a wireless communication network. The necessary parameter is an angle of arrival of radio waves (AOA). Arrival), Time of Arrival (TOA), Time Difference Of Arrival (TDOA), amplitude, phase, signal strength, and the like. The calculation of the location of these parameters on the network side is called network-based technology, and the parameters are received by the base station (BTS) and received by the mobile station (MS) and delivered to the network side. Can be classified by the method.

When using a network-based technology, the location can be determined without changing the existing terminal without additional equipment.

The Federal Communications Commission (FCC) mandate of the US states that by October 1, 2001, network-based technologies will be able to locate within a 100-meter radius for wireless E911 (Enhanced 911) services.

Next, referring to the terminal-based technology, it may be referred to as a technology based on the Global Positioning System (GPS). That is, a method of determining one's own location by using signal information of GPS satellites received by a GPS module built in a terminal, a method of determining one's own location by a GPS module, a terminal having a built-in GPS module, There is a method of determining the location by transmitting and receiving data with the network equipment that has information about the GPS satellites.

In case of using an external GPS, the cost of purchasing the GPS separately is increased, and the size of the terminal becomes large, making it difficult to carry.

On the other hand, when looking at the technology based on the dedicated network, this is a technology using a dedicated network for positioning, using a different frequency than the general wireless communication system. For example, a dedicated network in the US LMS (location and monitoring) band can be used, and a separate signal is used for location determination. This is a kind of road sign, and roadside base stations of the Intelligent Transportation System (ITS) are included in this category.

Dedicated network-based technology generally lacks economic feasibility because a separate network must be constructed for location verification. On the other hand, high accuracy can be achieved if the signal is also designed for a specific application and installed in some areas.

In addition to the above-described method, there is a radio camera technology that determines a location by receiving a signal transmitted from a terminal in a network similar to the network-based technology.

RadioCamera technology finds a location by comparing the fingerprint of a wireless signal type with the current user's wireless signal type in advance. The technology uses a database of user signals received via multipath and radio signal propagation that is already established to enable continuous location measurements regardless of the user's own location requirements.

In addition, although no special positioning technique is used, the positioning is performed by an identifier (ID) of a base station or a sector in the base station area. That is, it is possible to identify its position by the sector ID in the base station or the base station area that is being served by the digital cellular mobile communication system or the PCS system. However, since the size of a sector in a base station or a base station area in a cellular mobile communication system or a PCS varies, the accuracy with respect to the position also varies greatly.

However, in the conventional wireless communication system, the location tracking (mobile positioning) service is provided when the mobile station MS receives a high power transmission command from the base station BTS and transmits at a higher power than normal power. Including at least three base stations to capture the terminal signal to use the method of tracking the location of the terminal. That is, in the conventional wireless communication system, at least three base stations receiving a signal of the terminal must be available for tracking the location of the subscriber. Therefore, this method is not suitable for an in-building system in which one base station serves several layers simultaneously.

Recently, the location tracking (mobile positioning) service using the wireless communication system has been increasing interest in the method of serving the interior of the building independent of the external environment. This is because the inside of the building is attenuated by outside walls due to transmission loss caused by the building walls, it is difficult to receive a signal of sufficient intensity, it is efficient to service only the inside of the building with a separate base station in a high user density building, This is due to the high application areas such as wireless PBXs in buildings using in-building systems. In addition, since the IMT-2000 service supports a high data rate, the wireless local area network (WLAN) function can be implemented in combination with the in-building system. The basic structure of the wireless communication system for the in-building service is as shown in FIG. 1.

As shown in FIG. 1, a wireless communication system (in-building system) for an in-building service includes a base station controller (BSC) 11 and a base station (BTS) 12 to which an existing switching function is added. It consists of a main unit (13), a remote unit (14) and an antenna.

That is, the inbuilding system connects the base station (BTS) 12 to the switching center (MSC) to coordinate the connection between the base station (BTS) 12 and the base station (BTS) 12 and the switching center (MSC: Mobile Switching Center). A control station (BSC) 11 which performs a signal processing function for communication between the mobile station MS and the mobile station MS is connected to the control station BSC 11 and communicates with the mobile station MS through a wireless communication system. 11 is a base station (BTS) having a wired / wireless conversion function for communicating with a wire (11), and a main unit for converting a baseband signal from the base station (BTS) 12 into an optical signal (Main) Unit 13, a plurality of remote units 14 connected to the main unit 13 by an optical cable and converting an optical signal into a service frequency band, and a coaxial cable to the plurality of remote units 14 It consists of multiple antennas that are connected one-to-one with (RF cable).

The detailed structure of the inbuilding system is as shown in FIG.

The main units 14a to 14n convert baseband signals from the base station 12 to optical and transmit them to the remote units 14a to 14n via optical cables, and the remote units 14a to 14n transmit the optical signals at radio frequency. Converts and amplifies (RF) signals and radiates them through an antenna. At this time, considering the transmission loss of the optical cable and coaxial cable is limited to 1Km between the main unit 13 and the remote unit 14a-14n, and 30-40m between the remote unit 14a-14n and the antenna. In addition, the service radius of one antenna depends on the material, internal structure, and internal components of the building, but is generally designed to have a radius of 30 ~ 40m.

Each antenna will be placed on or above each floor of the building for service. The number of antennas placed per floor depends on the area of the building and the internal structure of the building. This is because the radius that can be serviced by one antenna is determined by the building's internal structure (building material, layout of the room inside the building, partition material, etc.). Therefore, according to the service radius of the antenna is arranged in each floor or within the same floor for each zone to service. In such an building system, an entire building is serviced by one base station or more than one base station according to a required capacity.

However, signals from each base station are transmitted through the main unit 13 connected to the base station 12 and the several remote units 14a to 14n connected to the main unit 13, and the main unit 13 and the remote unit ( 14a to 14n provide only baseband / optical conversion, optical / high frequency band conversion, and amplification functions, so it is not possible to distinguish which antenna or which remote unit 14a-14n the subscriber's signal is inputted through. Therefore, there is a problem that the location tracking (mobile body positioning) service in the building (in-building) is impossible.

The present invention has been proposed to solve the above problems, a mobile positioning method for implementing a subscriber location (mobile positioning) function in the building (in-building) using the delay time in a wireless communication system and It is an object of the present invention to provide a computer-readable recording medium having recorded thereon a program for realizing the method.

1 is an exemplary configuration of a wireless communication system for a general in-building service.

2 is an explanatory diagram showing a conventional mobile positioning process for in-building services.

3 is an explanatory diagram showing the center of the search window and the size of the search window of the base station used in the present invention.

4 is a diagram illustrating an embodiment of a mobile positioning method for an in-building service using a delay device according to the present invention.

5 is an explanatory diagram showing signal distribution from each antenna in the time domain according to an embodiment of the present invention;

* Explanation of symbols for the main parts of the drawings

11 control station (BSC) 12 base station (BTS)

13: Main Unit 14a ~ 14n: Remote Unit

15a ~ 15n: delay element

In order to achieve the above object, the present invention provides a method for positioning a moving object in a wireless communication system for an in-building service, comprising: installing a delay element at an antenna side installed in an area to be serviced in a building (in-building); A first step of setting the delay time of the delay element for each antenna; Calculating a time (RTD) at which the base station signal is transmitted to the mobile station and returned to the mobile station; And a third step in which the base station compares the delay time value of the preset antenna with the RTD value, identifies the antenna that the mobile station is serving, and determines the location of the mobile station therefrom.

The present invention for achieving the above object, for the in-building service, in the wireless communication system having a processor, the delay time of the antenna-side delay element installed in the area to be serviced in the building (in-building) for each antenna A first function of setting to different; A second function of calculating a time (RTD) at which the base station signal is transmitted to and returned from the mobile station to the base station; And the base station compares a delay time value of a preset antenna with the RTD value, identifies a antenna that the mobile station is serving, and records a program for realizing a third function for identifying the location of the mobile station therefrom. Provide a readable recording medium.

In the recent wireless communication system, one of the basic requirements of the operator is a location tracking service for emergency such as 119 service. Therefore, a location tracking function is required in a wireless communication system for an in-building service, but a function for tracking a location in an in-building environment is not implemented at present, and according to the present invention, location tracking was possible only in an outdoor environment. By implementing the function in a wireless communication system (in-building system) for the in-building service, it is possible to secure the competitiveness of the system.

To this end, the present invention provides a time delay device between the remote unit and the antenna in a wireless communication system for the in-building service, and sets the signal delay time differently for each antenna through the delay device, the delay time in the base station By identifying the antennas that are being serviced using, the subscriber location tracking function can be implemented in the in-building service.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

When the mobile station MS attempts to access, the base station (BTS) first searches the entire search range of the CSM (Cell Station Module) chip to obtain an access preamble and then receives an access message. . In this case, the pilot message includes pilot PN phase information as shown in Equation 1 below.

PILOT_PN_PHASE = (PILOT_ARRIVAL + (64 × PILOT_OFFSET) mod 2 ¹⁵

In Equation 1, "PILOT_ARRIVAL" is the arrival time of the multipath component first arriving from the base station (BTS) to the mobile station (MS), and "PILOT_OFFSET" is the pilot PN Offset value of the base station (BTS). to be.

In order for the base station BTS to continuously acquire a signal from the mobile station MS, the searcher sets a search window having an Acquisition Window Length and searches for the signal of the mobile station MS. At this time, the base station (BTS) uses the pilot pseudo-noise phase (PILOT_PN_PHASE) included in the access message from the mobile station (MS) when the base station signal is transmitted to the mobile station (MS) and returns, RTD (Round Trip Delay) value Using this value, you can set the center of the search window and set the search window to +/- Acquisition window length / 2 size based on the center. This is shown in FIG. 3.

The base station (BTS) receives a pilot PN phase value from the mobile station (MS), calculates the distance between the mobile station (MS) and the base station (BTS), that is, an RTD value, and sets a search window based on the value. Monitor the mobile station signal.

The RTD value varies depending on the distance between the mobile station MS and the base station BTS. This principle can be applied to a wireless communication system (in-building system) for an in-building service to implement a terminal location tracking (mobile body positioning) function.

That is, as shown in FIG. 4, delay elements a to n (15a to 15n) are provided between the remote units 14a to 14n and the antenna. At this time, the delay time D ₁ to D _{n of the} delay elements a to n (15a to 15n) is set differently for each antenna.

Here, n denotes the number of remote units 14a to 14n (= antenna number) connected to the base station 12, and D _n is a delay time for the n-th antenna. And, in D ₁ D _n is gatneunde regular time intervals, the time interval is set to "base station search the maximum time span / n".

When the delay time D ₁ to D _{n of} the delay elements a to n 15a to 15n is set differently for each antenna, the delay time value is maximized for each antenna in consideration of the error of the RTD value received from the mobile station MS. It needs to be set at wide intervals. To this end, since the time range that the base station (BTS) can search is a 256PN chip, the delay time value connected to each antenna is determined according to the number of remote units 14a to 14n connected to the base station 12. That is, assuming that the number of antennas connected to one base station 12 is n, the time interval between the antennas is set to " 256PN chips / n ". In this case, the time from the mobile station MS is distributed at regular intervals over the entire search range of the base station 12 as shown in FIG. 5, and the base station 12 stores the RTD values for each mobile station MS. Because of the calculation, it is possible to identify which antenna or which remote unit 14a-14n the subscriber's signal has been input from the RTD value.

At this time, the base station 12 should know the information about the predetermined delay time in each antenna. That is, the base station 12 can determine the position of the antenna that is input in advance from the calculated RTD value and transmit the information about the position to the desired user. In general, the wireless communication system for the in-building service (in-building system) Since the service radius of one antenna within 30 ~ 40m in this way, it is possible to track the location of the subscriber within the range of 30 ~ 40m without using multiple base stations using this method.

This will be described in more detail with reference to FIG. 5.

FIG. 5 shows each antenna in the time domain when delay elements a to n (15a to 15n) are installed between the remote units 14a to 14n and the antenna in a wireless communication system (inbuilding system) for inbuilding services. Shows the signal distribution of.

With respect to the signal coming from the first antenna, the signal of the mobile station MS is distributed at a time corresponding to the sum of the delay time RTD ₁ and the intentional delay time D ₁ by the distance between the mobile station MS and the antenna. Done. Therefore, the center degree base station 12 of the search window receives the corresponding pilot PN phase from the mobile station MS and sets it to "RTD ₁ + D ₁ ". At this time, the base station 12 can identify the antenna if the base station 12 only has information on which antenna is a signal having an RTD value of about D ₁ (≒ RTD ₁ + D ₁ ), the radius of the antenna is 30 ~ 40m range As a result, the position of the mobile station MS can be determined within the range of 30 to 40 m.

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

The present invention as described above, by installing a time delay element between the remote unit and the antenna and set the delay time for each antenna to identify the antenna serving by using the delay time in the base station, the subscriber location in the in-building service There is an effect that can implement the tracking (mobile body positioning) function.

Claims (5)

A mobile positioning method in a wireless communication system for an in-building service, A first step of installing a delay element at an antenna side installed in an area to be serviced inside an building (in-building), and setting a delay time of the delay element for each antenna; Calculating a time (RTD) at which the base station signal is transmitted to the mobile station and returned to the mobile station; And A third step of identifying, by the base station, a delay time value of a preset antenna and the RTD value, identifying the antenna that the mobile station is serving and determining the location of the mobile station; Moving object positioning method for in-building service using delay element The method of claim 1, The delay element, The delay element is installed between the remote unit and the antenna, the delay time is set differently for each antenna, the delay time value is set at the widest interval for each antenna in consideration of the error of the RTD value received from the mobile station Mobile positioning method for in-building service using The method of claim 2, The delay time interval for each antenna, And a maximum searchable range (256 pseudo-noise (PN) chip) / antenna of the base station. The method according to any one of claims 1 to 3, The antenna, Installed in the area to be serviced inside the building (in-building), each antenna has a different delay time value, the delay time value of each antenna is characterized in accordance with the number of remote units connected to the base station Moving object positioning method for in-building service using delay element. In the wireless communication system having a processor for the in-building service, A first function of setting a delay time of an antenna-side delay element installed in an area to be serviced inside an building for each antenna; A second function of calculating a time (RTD) at which the base station signal is transmitted to and returned from the mobile station to the base station; And A third function in which the base station compares a delay time value of a preset antenna with the RTD value to identify an antenna that the mobile station is serving and to determine the location of the mobile station; A computer-readable recording medium having recorded thereon a program for realizing this.