JPH0819035A - Position detection system - Google Patents

Abstract

PURPOSE:To easily detect a position of a mobile station by providing an output of distance information from a stationary station to a mobile station and posi tion information of the mobile station comprising information of the directivity of an antenna. CONSTITUTION:A mobile station 7 detects a reply signal when a call signal from a base station is directed to the mobile station 7. A radio base station 1 uses a beam control section 2 to control a beam control antenna 5 thereby directing the beam in a direction in which a signal from the mobile station 7 is received with highest strength and fixing. In this state, the radio base station 1 emits a radio wave to the mobile station 7. Upon the receipt of a radio wave from the radio base station 1, the mobile station 7 emits a radio wave to the radio base station 1 after the lapse of a prescribed time (A). Then the radio base station 1 uses a communication range measurement section 3 to obtain a delay time based on a time when the radio base station 1 emits a radio wave and an arrival time of a reply signal from the mobile station 7 and calculate a half of a value subtracting processing time (A) from the time and the distance (L) up to the mobile station 7 is calculated from the value and the luminous flux.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system capable of ascertaining the position of a moving body using wireless communication, and in particular,
In a communication system having a fixed station and a mobile station,
The present invention relates to a system in which a fixed station can search the position of a mobile station and output information on the position.

[0002]

2. Description of the Related Art As one of the methods for searching the position of a moving animal or the like by using a wireless communication means, a radio wave transmitted from a wireless transmitter attached to the body of an animal is received by an antenna having a strong directivity. Then, there is a method of determining the direction in which an animal or the like exists from the pointing direction of the antenna and the distance to the animal or the like from the reception level.

Since this method is very simple, it is often used for ecology research of wild animals, but it is difficult to measure with high accuracy due to its configuration, and a permanent system is used. There is no hope of building a general-purpose system that anyone can use anytime.

Further, as another method for measuring the position of a moving object or the like by using radio waves, there is a radar device. This is because the radio wave radiated by scanning the measurement area with beam-shaped radio waves is reflected by the object to be measured and received back (reflected wave), and the transmission time of the radio wave and the reflected wave are received. The distance is determined from the time relationship with the reception time, and the direction of the DUT is specified from the beam irradiation direction.

This radar device is widely used for aircraft and ships. Furthermore, as means for detecting the position of a moving body using radio waves, GPS (Global)
There is a Positioning System).

This is a navigation system using artificial satellites operated by the US Department of Defense. In this navigation system, there are four satellites in six different orbits, one orbiting the earth at an altitude of about 20,000 km, a tilt angle of 55 °, and about 12 hours.
A total of 24 satellites (including 6 spares) are installed, and the high-precision atomic clock mounted on the satellites is used to calculate the distance on the terminal side based on the delay time from multiple satellites. This allows the current position to be recognized.

The navigation signal transmitted from the satellite includes a P code (Precision Code) and a C / A code (Clear and Acquisition Cod).
e) The frequency used is L1 and is 1575.
Two waves of 1227.60 MHz are used as 42 MHz and L2.

Then, the P code and the C / A code are sent in L1, and only the P code is sent in L2. C / A
Only the code is open to the public, and many systems currently on the market use this code. All satellites use the same frequency, and the modulation method is spread spectrum modulation.

A navigation signal from a satellite is received by a receiver on the ground, the time information of the satellite and the orbital element are decoded, and the position of the satellite and the distance from each satellite to the receiver are calculated. Signals from three satellites are received, and the intersection of three spheres drawn on the earth centering on the satellites is the position (latitude and longitude) of the receiver. With four signals, the altitude of the receiver (altitude) Can also be calculated.

In this navigation system, if the signals from four or more of the 24 satellites can be captured, positioning can be performed not only on the sea on the earth but also on land and in the sky. It has high versatility and can perform positioning in a short time without being affected by time and weather.
It is a system that can measure with a relatively high accuracy (nominal 100 m).

[0011]

The radar device described above cannot be used when there is a large obstacle between the radar device and the object to be measured that reflects or absorbs radio waves. Therefore, it is impossible to construct a system for measuring the position of a specific object to be measured on the ground surface in a city with many buildings.

Further, the radar device is expensive and economically unsuccessful. On the other hand, in GPS, the mobile station must be equipped with means for receiving radio waves from at least three artificial satellites, detecting the delay times of each, and calculating the distance to each artificial satellite from them. It is difficult to miniaturize the mobile station due to the large amount.

Further, in order to know the position of the mobile station on the fixed station side, for example, the fixed station instructs the mobile station to perform positioning, and based on this, the mobile station performs positioning, and the result is fixed station. However, it is not a good idea because the amount of information transferred between the fixed station and the mobile station is large and the control becomes complicated.

The present invention has been made in view of such conventional problems.
The objective is to realize a "mobile station position detection system" that can be constructed economically without increasing the size of the mobile station. Still another object of the present invention is to provide a method capable of forming the mobile communication system as a system having a function of detecting the position of a mobile station by making a slight modification to the existing mobile communication system. To do.

[0015]

According to the present invention, the above mentioned objects are achieved by the means defined in the claims.

That is, according to the invention of claim 1, in a communication system comprising a fixed station and a mobile station, the fixed station is
An antenna device capable of changing a directivity direction or a directivity characteristic in a horizontal plane by a given control signal, a directivity direction of the antenna device, or a means for generating a control signal for controlling the directivity characteristic, and moving. The signal sent to the station,

On the other hand, means for calculating the distance to the mobile station from the time relationship with the signal returned from the mobile station is provided, and when the mobile station receives a signal from the fixed station to itself, After a certain period of time, a means for transmitting a signal including the identification number of the own station to the fixed station is provided, and the fixed station transmits a radio signal in all directions in the horizontal plane to call the mobile device,

In response to this, when the mobile station returns a signal to the fixed station, the pointing direction of the antenna is controlled so that the received signal from the mobile station becomes maximum, and the return signal from the mobile station is controlled. And information about the position of the mobile station, which is composed of distance information from the fixed station to the mobile station calculated from the time relationship between the radio signal transmitted to the mobile station and the mobile station, and information on the pointing direction of the antenna. It is a configured position detection system.

According to a second aspect of the present invention, in a communication system including a fixed station and a mobile station, the fixed station can change a directivity direction or a directivity characteristic in a horizontal plane according to a control signal given to the fixed station. A possible antenna device, the pointing direction of the antenna device, or a means for generating a control signal for controlling the directional characteristics, and a signal sent to the mobile station,

On the other hand, means for calculating the distance to the mobile station from the time relationship with the signal returned from the mobile station is provided, and when the mobile station receives a signal from the fixed station to itself, After a certain period of time, a means for transmitting a signal including the identification number of the own station to the fixed station is provided, and the fixed station transmits a radio signal in all directions in the horizontal plane to call the mobile device,

In response to this, when the mobile station returns a signal to the fixed station, the pointing direction of the antenna is controlled so that the received signal from the mobile station is maximized, and the signal is again directed to the mobile station. A radio signal is transmitted, and from the time relation between the radio signal and the return signal from the mobile station, the distance information from the fixed station to the mobile station calculated, and the information on the pointing direction of the antenna of the mobile station It is a position detection system that outputs position-related information.

According to a third aspect of the present invention, the antenna device according to the first or second aspect of the invention is configured so that the antenna element is mechanically circularly moved in a horizontal direction to change its pointing direction. It is a thing.

According to a fourth aspect of the present invention, the antenna device according to the first or second aspect of the invention is provided with a plurality of antenna elements, a phase shifter connected to each antenna element, and a phase shift amount of the phase shifter. And a beam control circuit for changing the directivity of the antenna.

The invention of claim 5 is the above-mentioned claims 1 to 4.
The fixed station according to the invention is a radio base station of a mobile communication system, which is configured to be connected to the telephone switching network.

[0025]

According to the invention of claim 1, when the fixed station sends a radio signal in all directions within the horizontal plane of the antenna device to call the mobile station, and the corresponding mobile station responds by returning the signal. , Control the pointing direction of the antenna so that its reception level is maximized.

That is, the mobile station is in the direction in which the antenna of the fixed station is pointing. Also, when a fixed station calls the mobile station, the mobile station that has detected this returns a signal after a fixed time (A) has passed, so the fixed station receives the signal from the mobile station at the signal transmission time (T). The distance (L) from the reception time (R) and the speed of light (C) to the mobile station is calculated by the following equation.

L = C {(R-T-A) / 2} At this time, the mobile station transmits a signal after a predetermined time (A) has elapsed because the mobile station confirms the received signal and performs a transmission operation. This is to secure the time until the start of the measurement and to make sure the transmission and reception of signals to ensure the measurement operation and improve the accuracy. The fixed station outputs these pieces of information (direction of the mobile station and distance from the fixed station).

According to a second aspect of the present invention, in the above-mentioned first aspect of the invention, when the fixed station sends out radio waves in all directions and the mobile station sends out a signal accordingly, the reception level becomes maximum. After deciding the directional direction of the antenna of the fixed station, the radio wave is again sent to the mobile station, and the distance is calculated by the previous equation using the sending time and the arrival time of the return signal from the mobile station. To do.

According to a third aspect of the present invention, in the first and second aspects of the invention, the antenna of the fixed station is mechanically circularly moved (rotated) in a horizontal plane. It scans (360 °) and operates so as to direct the antenna in the direction in which the reception level from the mobile station is maximized.

According to a fourth aspect of the present invention, the antenna device according to the first and second aspects is provided with a plurality of antenna elements, a phase shifter connected to each antenna element, and a phase shift amount of the phase shifter. And a beam control circuit for changing the directivity of the antenna to electrically control the directivity of the antenna, thereby controlling the directivity of the antenna.

A fifth aspect of the present invention is based on the first to fourth aspects of the invention, wherein a fixed base station is a radio base station of an existing mobile communication system (having a connection relationship with a telephone switching network). According to this method, the present invention can be easily applied to an existing mobile communication system.

[0032]

FIG. 1 is a diagram showing an embodiment of the present invention.
Reference numeral 1 is a radio base station, 2 is a beam control unit, 3 is a communication distance measuring unit, 4 is a radio zone of the radio base station 1, 5 is a beam control antenna, 6-1 to 6-n are beams, and 7 is moving. Represents a station.

FIG. 2 is a flow chart showing an example of the procedure for calculating the distance, and S-1 to S-6 respectively represent steps of the operation. The operation of the embodiment will be described below with reference to FIGS.

In FIG. 1, consider the case where the radio base station (fixed station) 1 searches for the position of the mobile station 7. Wireless base station 1
Controls the beam control antenna 5 by the beam control unit 2 to send a paging signal to all mobile stations in the radio zone 4 of the radio base station 1 in all directions of 360 degrees ( For example, the antenna is made omnidirectional.) Radio waves are emitted. (S-1 in FIG. 2)

Upon receiving the calling signal from the base station, the mobile station 7 identifies whether or not it is for itself, and if it is for itself, issues a response signal. . (S-2 in FIG. 2) In the radio base station 1, the beam control unit 2 controls the beam control antenna 5 to direct and fix the beam in the direction in which the signal from the mobile station 7 can be received most strongly. (S-3 in FIG. 2)

In this state, again the radio base station 1 to the mobile station 7
When the mobile station 7 receives the radio wave from the radio base station 1, the mobile station 7 emits the radio wave to the radio base station 1 after a certain time (A) has passed (S-4 in FIG. 2) (FIG. 2). S-5)

In the radio base station 1, the communication distance measuring unit 3 is
The delay time is calculated from the time when the radio wave is emitted from the radio base station 1 and the arrival time of the response signal from the mobile station 7 to the radio wave, and 1 / the value obtained by subtracting the predetermined time (A)
The value of 2 is calculated, and the distance (L) from this and the speed of light to the mobile station 7 is calculated. (S-6 in FIG. 2)

FIG. 3 is a diagram showing an example of the configuration of a beam control antenna of a radio base station, numeral 2 indicates the beam control unit of FIG. 1, and 9 indicates a beam control circuit and 10
-1 to 10-n are phase shifters, 11-1 to 11-n, respectively
Is an antenna element, and 12 is a beam.

In the figure, antenna elements 11-1 to 11-1
Phase shifters 10-1 to 10-n are connected to 1-n, respectively, and by controlling the phase shift of the phase shifters by the beam control circuit 9, the antenna elements 11-1 to 11- are connected.
The directional characteristics of the beam control antenna 5 composed of n and the beam 1
The direction of 2 can be changed.

In the present embodiment, as described above, first, the antenna directivity is set to 360 degrees (non-directional), radio waves are emitted, and when the mobile station responds to this, the mobile station responds. The beam is controlled to be narrowed down so that the reception level of the radio wave emitted by is maximized.

Further, in the beam control antenna as shown in FIG. 3, since the radiation beam can be scanned by electrically switching the phases of the respective elements at a high speed in accordance with a certain rule, the response signal from the mobile station is scanned by the beam. The position can also be detected by scanning.

As such a beam control antenna, there are known phased array antennas, adaptive array antennas and the like. FIG. 4 is a diagram showing another embodiment of the present invention, showing a case where the present invention is applied to an existing mobile communication system as a position detection service.

In the figure, numeral 13 is a public telephone network, 14-1 and 14-2 are exchanges, 15 is an end office (shown as EO in the figure), 16 is a subscriber's house, 17 is a telephone, and 18 is an interface. Subscriber module (I in the figure
SM is described, 19 is an ISM adapter (ISMA in the figure)
, 20 is a radio base station (described as BS in the figure), 2
Reference numeral 1 indicates a wireless zone, and 22 indicates a mobile station.

A case where the user tries to confirm the current position of the mobile station through the telephone will be described with reference to FIG.

In FIG. 4, when the user in the subscriber's house 16 hooks off the telephone set 17, the user is connected to the end office 15. When the user inputs the identification code of the position detection service and the telephone number of the mobile station 22 from the telephone, the information is stored in the end office 15, the exchange 14-1, and the exchange 14.
-2, the interface subscriber module 18, and the interface subscriber module adapter 19 are transmitted to the radio base station 20.

In response to this, the radio base station 20 calls the mobile station 22 with the antenna in an omnidirectional state. The mobile station 22 sends a response signal to the radio base station 20 when it knows that the mobile station 22 is calling itself.

The radio base station 20 narrows the beam of the antenna and directs the beam of the antenna toward the mobile station 22 so that the reception level of the response signal becomes maximum. Then, the signal is transmitted again to the mobile station 22. When the mobile station 22 receives this signal, it sends out a response signal after a lapse of a certain time.

Upon receiving the response signal, the wireless base station 20 receives the response signal from the generation time of the previous signal, the arrival time of the response signal, the delay time (constant time) in the mobile station 22, and the speed of light. And the distance L between the mobile station 22 and the mobile station 22 are calculated.

Then, the information on the pointing direction of the antenna and the value of the distance are transferred to the end office 15 through the ISM adapter 19, the exchange 14-2 and the exchange 14-1.
At the end office 15, the voice is synthesized based on the transferred information, and the location of the mobile station 22 is determined by the telephone 1
The user is notified by voice through the handset of No. 7.

In the above embodiment, the case where the present invention is applied to the mobile communication system in which one radio base station constitutes a single omni zone is described, but the present invention is not limited to this, and the radio zone is It is obvious that the present invention can be applied to the case where it is composed of a plurality of sectors and the case where the service area is composed of plural zones.

Further, the present invention can be applied to a mobile communication system in which a mobile station is called by a dedicated antenna element and a signal is transmitted / received after a line is set up by a call antenna element.

In the above description, the distance of the mobile station is measured from the signal delay time based on the signal transmission time from the radio base station and the arrival time of the response of the mobile station to the signal. This delay time is originally the carrier wave (radio signal)
However, if the delay time of the carrier can be measured, the result is the same even if it is detected by the modulation signal.

The present invention is capable of detecting the position of a mobile station with a particularly high accuracy when the uplink and downlink transmission paths are reversible such that communication is performed alternately using the same frequency.

[0054]

As described above, according to the position detecting system of the present invention, the position of the mobile station can be easily detected by the radio base station (fixed station), and the position of the mobile station can be detected with high accuracy. There is an advantage that information on the existing position can be obtained.

According to the present invention, for example, an ultra-compact mobile station dedicated to position detection is made and carried by an infant or an elderly person having a poor memory ability.
If you get lost, you can easily identify where you are.

In addition, when the mobile station is attached to the body of an animal when conducting an ecological survey of the animal, the behavior of the mobile station can be easily investigated.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a procedure for calculating a distance.

FIG. 3 is a diagram showing an example of a configuration of a beam control antenna.

FIG. 4 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1,20 Radio base station 2 Beam control unit 3 Communication distance measuring unit 4,21 Radio zone 5 Beam control antenna 6-1 to 6-n Beam 7,22 Mobile station 9 Beam control circuit 10-1 to 10-n Phase shift Equipment 11-1 to 11-n Antenna element 12 Beam 13 Public telephone network 14-1, 14-2 Switch 15 End office 16 Subscriber home 17 Telephone 18 Interface subscriber module 19 ISM adapter

Claims (5)

[Claims] 1. A communication system comprising a fixed station and a mobile station, comprising: an antenna device capable of changing a directivity direction or a directivity characteristic in a horizontal plane by a control signal given to the fixed station; The means for generating a control signal for controlling the directivity or directivity of the antenna device, and the time relationship between the signal sent to the mobile station and the signal returned from the mobile station. A means for calculating the distance to the mobile station is provided, and when the mobile station receives a signal from the fixed station to itself, a signal containing the identification number of the own station is sent to the fixed station after a certain period of time. When the fixed station sends a radio signal in all directions in the horizontal plane to call the mobile station and the mobile station returns the signal to the fixed station accordingly, the mobile station sends the radio signal to the fixed station. Received from Controlling the pointing direction of the antenna so that the signal becomes maximum, and distance information from the fixed station to the mobile station calculated from the time relationship between the return signal from the mobile station and the radio signal transmitted to the mobile station, A position detection system, which outputs information relating to the position of a mobile station, the position detection system including information on the pointing direction of the antenna. 2. A communication system comprising a fixed station and a mobile station, comprising: an antenna device capable of changing a directivity direction or a directivity characteristic in a horizontal plane by a control signal given to the fixed station; The means for generating a control signal for controlling the directivity or directivity of the antenna device, and the time relationship between the signal sent to the mobile station and the signal returned from the mobile station. In addition to providing a means for calculating the distance to the mobile station, when the mobile station receives a signal from the fixed station to itself, after a certain period of time, it sends a signal containing the identification number of the own station to the fixed station. Means is provided, the fixed station sends out radio signals in all directions in the horizontal plane to call the mobile station, and when the mobile station returns the signal to the fixed station in response to this, from the mobile station, Received The directional direction of the antenna is controlled so as to maximize the value, the radio signal is sent again to the mobile station, and the fixed value calculated from the time relationship between the radio signal and the return signal from the mobile station to this radio signal is fixed. A position detection system, which outputs information relating to the position of a mobile station, which is composed of distance information from the station to the mobile station and information on the pointing direction of the antenna. 3. The position detecting system according to claim 1, wherein the antenna device mechanically circularly moves the antenna element in a horizontal direction to change the direction of the antenna element. 4. The antenna device comprises a plurality of antenna elements,
3. The position detection system according to claim 1, further comprising a phase shifter connected to each antenna element, and a beam control circuit that controls the amount of phase shift of the phase shifter to change the directional characteristics of the antenna. 5. The position detection system according to claim 1, wherein the fixed station is a radio base station of a mobile communication system, and the radio base station is connected to a telephone switching network.