JP5222506B2 - Position detection system, position detection method, and base station - Google Patents

Description

The present invention relates to a position detection system, a position detection method, and a base station that detect the position of a moving object using a leaky coaxial cable.

  In recent years, in addition to cellular networks such as IEEE 802.11 WLAN (Wireless Local Area Network), third-generation mobile phones, and PHS (Personal Handyphone System), WPAN (Wireless Personal Area Network) that forms networks by short-range wireless The wireless communication environment surrounding people and things is changing. As a result, services using radio are diversified, and one of them is a service for detecting the position of a person or an object using a mobile terminal or various sensors.

  As a position detection system of a wireless terminal using an electric signal, for example, a GPS (Global Positioning System) system using a radio wave from an artificial satellite, a system using a radio wave from a base station of a cellular system, a wireless LAN (Local Area Network) A number of position detection systems based on the positioning principle of three-point positioning have been proposed and provided, such as a system using the radio waves of access points) and a system using radio waves of wireless nodes in a sensor network. As described above, in the position detection system, there are technologies using radio, RFID (Radio Frequency IDentification), ultrasonic waves, and the like, including GPS used in car navigation and mobile phones.

  Among the position detection systems using the wireless technology as described above, a technology for measuring the arrival time of radio waves at a base station and performing three-point positioning uses TDOA (Time Difference Of Arrival), and GPS This method is used for detecting the position of a mobile phone or a CDMA mobile phone or WiFi terminal. Further, a CS-ID (IDentification) method for finding a terminal connected to a base station (CS: Ce11Station) is used in PHS. Furthermore, a technique for measuring radio field intensity at a base station and performing three-sided positioning uses RSSI (Received Signal Strength Indicator) and is used for position detection by RFID.

  By the way, GPS presupposes position detection outdoors, and cannot be used in places where GPS radio waves cannot be received, such as tunnels and underground malls. In addition, in the terminal position detection method using a sensor node or a base station of a cellular system, there is a common problem that the position detection accuracy is lowered due to the influence of multipath fading or a propagation path out of line of sight.

  Therefore, it is conceivable to use a leaky coaxial cable (hereinafter also referred to as LCX) as an antenna as a base for wireless transmission and reception. According to LCX, a cable laid over several tens of meters can be used as an antenna. There are not a few radio shielding spaces in the subway and underground malls, but it is obliged by the Fire Service Act to ensure an emergency contact network between the ground and underground in the event of a fire or accident. LCX is installed in many buildings. It is laid. In recent years, a high-bandwidth LCX capable of transmitting the 2.4 GHz band has appeared, and a communication infrastructure in public spaces is being developed.

  Detecting the location of the terminal using the LCX communication infrastructure as it is does not require a new laying work and can provide a service quickly, so it is very versatile. It can be said. Therefore, a terminal position detection method using LCX has been proposed.

  As a conventional technique for position detection using such a leaky coaxial cable (LCX), a technique for position detection using two types of PN (Pseudo Noise) signals (for example, Patent Document 1), or a technique for sandwiching a road 2 A technique for performing position detection using an LCX of a book has been proposed (for example, Patent Document 2).

In addition, a method in which an antenna receives an electrical signal output from a transmission unit mounted on a vehicle and performs position detection based on electrical signals output from both ends of the antenna (LCX) (for example, Patent Document 3), There is a technique for measuring the impulse response using two LCXs and performing position detection in the longitudinal direction (for example, Patent Document 4), and a technique for performing position detection using two LCXs and two radio frequencies ( For example, Patent Document 5).
Japanese Patent Laid-Open No. 9-16886 JP-A-10-288657 Japanese Patent Laid-Open No. 11-161892 JP 2004-98779 A JP 2004-125604 A

However, the above-described conventional technology for performing position detection using LCX requires two LCXs that play the role of a transceiver in principle, or two types of signals for position detection. There is a problem that the configuration of the transceiver is complicated.
The present invention has been made in view of such circumstances, and provides a position detection system that uses a single LCX and detects position information by two-dimensional positioning using a single frequency band.

In order to solve the above-described problems, the present invention provides a position detection system including a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, coaxial cable, a communication terminal is connected terminations to the base station so as to output an electrical signal to the base station, Ri other end der the electrical signal is configured to reflect propagating within the own cable, previously And a reflection terminal including a band filter for reflecting only a predetermined frequency band of the electric signal , the mobile terminal includes signal transmission means for transmitting the electric signal to the leaky coaxial cable, and the base station includes the mobile terminal. an electrical signal leakage coaxial cable has reception transmitted from the direct wave receiving means for receiving a direct wave is an electric signal which is input to the communication terminal from the leakage coaxial cable without being reflected by the reflecting end Reflected wave receiving means for receiving a reflected wave that is an electric signal input to the communication end after being reflected by the reflection end of the leaky coaxial cable, and direct wave reception time information indicating the time when the direct wave receiving means has received the direct wave. And calculating means for calculating position information of the mobile terminal based on the reflected wave reception time information indicating the time when the reflected wave receiving means receives the reflected wave.

The present invention relates to a position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, and the leaky coaxial cable receives an electrical signal from the base station. a communication terminal is connected terminations to the base station so as to enter the self-configured other end der as cable electrical signals propagating within is reflected is, the predetermined electric signal frequency band A reflective end having a bandpass filter for reflecting only the mobile terminal, and the mobile terminal leaks the coaxial cable before being reflected at the reflective end by an electrical signal output from the base station to the leaky coaxial cable via the communication end. A direct wave receiving means for receiving a direct wave radiated from the leaky coaxial cable into the space, and a reflection radiated from the leaky coaxial cable into the space by the electric signal after being reflected at the reflection end of the leaky coaxial cable On the basis of the reflected wave receiving means for receiving the reflected wave, the direct wave receiving time information indicating the time when the direct wave receiving means received the direct wave, and the reflected wave receiving time information indicating the time when the reflected wave receiving means received the reflected wave. A base station is connected to the communication end of the leaky coaxial cable and transmits an electric signal to the mobile terminal via the leaky coaxial cable; It is characterized by providing.

The present invention relates to a position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, and the leaky coaxial cable receives an electrical signal from the base station. a communication terminal is connected terminations to the base station so as to enter the self-configured other end der as cable electrical signals propagating within is reflected is, the predetermined electric signal frequency band A reflective end having a bandpass filter for reflecting only the mobile terminal, and the mobile terminal leaks the coaxial cable before being reflected at the reflective end by an electrical signal output from the base station to the leaky coaxial cable via the communication end. A direct wave receiving means for receiving a direct wave radiated from the leaky coaxial cable into the space, and a reflection radiated from the leaky coaxial cable into the space by the electric signal after being reflected at the reflection end of the leaky coaxial cable The reflected wave receiving means for receiving the direct wave receiving means, the direct wave receiving time information indicating the time when the direct wave receiving means received the direct wave, and the reflected wave receiving time information indicating the time when the reflected wave receiving means received the reflected wave. A time information transmitting means for generating time information and transmitting the time information to the base station, and the base station is connected to the communication end of the leaky coaxial cable and transmits an electric signal to the mobile terminal via the leaky coaxial cable. Based on the transmission means, the time information reception means for receiving the time information transmitted from the time information transmission means, the direct wave reception time information detected from the time information, and the reflected wave time information, the location information of the mobile terminal And calculating means for calculating.

を計算することによって位置情報を算出することを特徴とする。 In the present invention, the calculation means uses the value of the X coordinate in a two-dimensional coordinate and Y when the leaky coaxial cable is the X axis, the direction perpendicular to the X axis is the Y axis, and the communication end is the coordinate origin. The value of the coordinates, where the X coordinate is (X˜), the Y coordinate is (Y˜), the direct wave reception time information is t1, the reflected wave reception time information is t2, and the leaky coaxial cable The propagation speed of the electrical signal in the interior is v, the propagation speed of the electrical signal in space is c, the length of the leaky coaxial cable is l, the Y axis, the mobile terminal, and the leaky coaxial cable. The angle between the electric signal propagation path between

The position information is calculated by calculating.

The present invention is a position detection method by a position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, the communication terminal is a terminal is, and outputting an electrical signal to the base station, Ri other end der, reflecting end with a bandpass filter for reflecting only the frequency band of the predetermined said electrical signal, and a step of reflecting the electrical signal propagating within the own cable, of the mobile terminal, the signal transmitting means, comprising the step of transmitting the electrical signal to the leaky coaxial cable, of the base station, the direct wave reception means, electrically the leaky coaxial cable is transmitted from the mobile terminal is an electrical signal reception, inputted from the leakage coaxial cable without being reflected by the reflecting end to said communication terminal Receiving a direct wave as a signal, a reflected wave receiving means receiving a reflected wave that is an electric signal input to the communication end after being reflected by the reflection end of the leaky coaxial cable, and a calculation means However, based on the direct wave reception time information indicating the time when the direct wave receiving means receives the direct wave and the reflected wave reception time information indicating the time when the reflected wave receiving means receives the reflected wave, the Calculating position information of the mobile terminal.

The present invention relates to a position detection method using a position detection system including a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, a step communication end, when electric signals are inputted from the base station is, Ri other end der, reflecting end with a bandpass filter for reflecting only the frequency band of a predetermined electrical signal, the own cable internal Reflecting the electric signal propagating through the mobile terminal, before the direct wave receiving means of the mobile terminal reflects the electric signal output from the base station through the communication end to the leaky coaxial cable at the reflection end. The process of receiving the direct wave radiated from the leaky coaxial cable into the space and the reflected wave receiving means are emptied from the leaky coaxial cable by the electric signal after being reflected by the reflection end of the leaky coaxial cable. Receiving the reflected wave radiated therein, time information transmitting means, direct wave receiving time information indicating the time when the direct wave receiving means received the direct wave, and time when the reflected wave receiving means received the reflected wave And calculating the position information of the mobile terminal based on the reflected wave reception time information indicating the base station, the signal transmission means of the base station is connected to the communication end of the leaky coaxial cable, and via the leaky coaxial cable And transmitting the electrical signal to the mobile terminal, and receiving the time information transmitted from the time information transmitting means.

The present invention relates to a position detection method using a position detection system including a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, a step communication end, when electric signals are inputted from the base station is, Ri other end der, reflecting end with a bandpass filter for reflecting only the frequency band of a predetermined electrical signal, the own cable internal Reflecting the electric signal propagating through the mobile terminal, before the direct wave receiving means of the mobile terminal reflects the electric signal output from the base station through the communication end to the leaky coaxial cable at the reflection end. The process of receiving the direct wave radiated from the leaky coaxial cable into the space and the reflected wave receiving means are emptied from the leaky coaxial cable by the electric signal after being reflected by the reflection end of the leaky coaxial cable. Receiving the reflected wave radiated therein, time information transmitting means, direct wave receiving time information indicating the time when the direct wave receiving means received the direct wave, and time when the reflected wave receiving means received the reflected wave Generating time information including reflected wave reception time information indicating and transmitting to the base station, wherein the signal transmission means of the base station is connected to the communication end of the leaky coaxial cable, and the leaky coaxial cable A step of transmitting an electric signal to the mobile terminal via the time, a step of receiving the time information transmitted from the time information transmitting unit by the time information receiving unit, and a direct wave reception time detected from the time information by the calculating unit A step of calculating position information of the mobile terminal based on the information and the reflected wave time information.

The present invention relates to a position detection system including a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, and the leaky coaxial cable transmits an electric signal to the base station. A communication end that is a terminal connected to the base station so as to output and an other end that is configured to reflect an electric signal propagating through the own cable, and only a predetermined frequency band of the electric signal is A base station in a position detection system comprising a signal transmission means for transmitting an electrical signal to a leaky coaxial cable, wherein the mobile terminal is provided with a reflection end having a bandpass filter for reflection, and is leaked from the mobile terminal an electrical signal coaxial cable has reception, a direct wave receiving means for receiving a direct wave is an electric signal which is input to the communication terminal from the leakage coaxial cable without being reflected by the reflecting end A reflected wave receiving means for receiving a reflected wave is an electric signal which is input to the communication terminal after being reflected by the reflecting end of the leakage coaxial cable, a direct wave reception time information indicating the time at which the direct wave receiving means receives a direct wave , the reflected wave receiving means on the basis of a reflected wave reception time information indicating a time receiving the reflected wave and a calculation means for calculating the location information of the mobile terminal, comprising: a.

As described above, according to the present invention, since a single leaky coaxial cable is used and position information is detected using an electric signal having a single frequency, the configuration is compared with the prior art. A simplified position detection system with fewer elements can be provided.
Furthermore, according to the present invention, either the mobile terminal or the base station may output an electrical signal for position detection. In particular, when an electrical signal is output from the mobile terminal, the mobile terminal Can be transmitted, and a simplified position detection system can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a concept of a position detection system according to an embodiment of the present invention.
The position detection system according to the present embodiment is a mobile terminal 300 carried by a user, a base station 100 that performs radio communication with the mobile terminal 300, and a leaky coaxial cable that relays radio communication between the mobile terminal 300 and the base station 100. LCX200. One end of the LCX 200 is a communication end 220 connected to the base station 100, and the other end is a reflection end 210 configured to reflect an electric signal propagating through the LCX 200.

For example, a signal output from the mobile terminal 300 is received by the LCX 200 from two places (point A and point B) with an angle θ. A direct wave received by the LCX 200 from a point A closer to the base station 100 out of the points A and B first arrives at the base station 100. Of the points A and B, the signal received by the LCX 200 from the point B far from the base station 100 is reflected by the reflection end 210 and then arrives at the base station 100 as a reflected wave. The base station 100 receives the arrival signals of these two paths, and detects the two-dimensional position based on the propagation time or the propagation time difference between the direct wave and the reflected wave. Note that the present invention can also be applied when a signal is transmitted from the base station 100.
Thus, according to this embodiment, it is possible to detect and calculate the two-dimensional position of the mobile terminal 300 using a single leaky coaxial cable (LCX200).

<First Embodiment: Configuration>
FIG. 2 is a block diagram showing the configuration of the position detection system according to the first embodiment. The position detection system according to the present embodiment includes a base station 100-1, an LCX 200-1, and a mobile terminal 300-1.

The base station 100-1 includes a calculation unit 120-1, a direct wave reception unit 140-1, a reflected wave reception unit 150-1, a position display map information transmission unit 160-1, a display unit 170-1, And a map information storage unit 180-1.
The map information storage unit 180-1 stores in advance the installation status of the LCX 200-1 as map information. An example of the map information stored in the map information storage unit 180-1 is shown in FIG.
The calculation unit 120-1 is stored in the map information storage unit 180-1 based on the direct wave time information and the reflected wave time information received by the direct wave receiving unit 140-1 and the reflected wave receiving unit 150-1. The position information indicating the coordinate position of the mobile terminal 300-1 in the map information is calculated.

  Based on the position information calculated by the calculation unit 120-1, the position display map information generation unit 190-1 displays the corresponding position on the map information stored in the map information storage unit 180-1 as shown in FIG. In addition, position display map information which is map information on which a mark indicating the current position is displayed is generated. In FIG. 21, a star is shown as a mark indicating the current position, but any mark may be used. In the position display map information, the current position may be indicated as a mark, and numerical information on the coordinate position may be displayed. The display unit 170-1 is a display using liquid crystal or the like, and displays position display map information.

The direct wave receiving unit 140-1 receives a direct wave received at an angle θ from the slot 230-N (N is an arbitrary integer. For example, the slot 230-1) of the LCX 200, and the reflected wave receiving unit 150-1 Receives a reflected wave received at an angle θ from slot 230-M of LCX 200-1 (M is an arbitrary integer. For example, slot 230-2).
The position display map information transmission unit 160-1 transmits the position display map information generated by the position display map information generation unit 190-1 to the mobile terminal 300-1.

  LCX 200-1 is a leaky coaxial cable, and includes a reflection end 210-1, a communication end 220-1, a slot 230-1, a slot 230-2,... Slot 230-Q (Q is an arbitrary integer). It has. The leaky coaxial cable is a coaxial cable that transmits a high-frequency signal, and the entire cable functions as an antenna. As shown in FIG. 3, for example, the leaky coaxial cable includes four layers of a sheath 291, an outer conductor 292, an insulator 293, and an inner conductor 294. Then, by making a plurality of holes (also referred to as radiation holes) in the outer conductor 292 which is a conductor portion outside a general coaxial cable, radio waves are incident and radiated, and a plurality of adjacent slots interact with each other. Function as a transmission / reception antenna.

If the wavelength of the radio wave propagating in the leaky coaxial cable is sufficiently longer than the slot size, the radio wave radiated from the slot is equivalent to the radio wave radiated from the minute dipole, and the structure of the leaky coaxial cable is the length of the cable. The structure is such that minute dipoles are continuously arranged in the direction at intervals of the radiation holes. On the other hand, since the phase of the radio wave radiated from the slot depends on the phase of the radio wave propagating in the cable, the phase of the radio wave radiated from each slot is different. For this reason, the radio waves in the space radiated from the leaky coaxial cable are superimposed on the radio waves radiated from the slots and out of phase. For this reason, the radio wave has directional characteristics due to radio wave strengthening or weakening depending on the radiation angle. Here, the radiation angle θm of the radio wave is determined by the following equation (2) according to the interval P / 2 (meter) of the radiation hole of the leaky coaxial cable and the wavelength λ _RF (meter) of the carrier wave in the leaky coaxial cable.

  Here, in order to obtain a radiated wave, Equation (2) needs to be a real number, and for that purpose, m needs to be a negative integer. εr represents the relative dielectric constant of the insulator inside the leaky coaxial cable. That is, the electromagnetic wave propagating through the leaky coaxial cable and leaking outside becomes a radiated wave having the same radiation angle θm when the phase difference from each slot is 2Pnπ. There are a number of Pn satisfying this condition in the range where the expression (2) is a real number, and there are a plurality of radiation modes (m). This is called, for example, an m-order mode radiation wave, and has a relationship of m = 2n and m = 2n + 1 (for example, refer to the following literature: Toshihiko Kishimoto, Shin Sasaki, LCX communication system, Corona). That is, the radiation angle θm varies from −90 degrees to +90 degrees depending on the wavelength (frequency), with the radial direction of the cable being 0 degrees. Hereinafter, assuming that m = −1, θm is simply expressed as θ. In addition, in order to perform position detection using Formula (1), it is necessary to make m of Formula (2) constant. In general leaky coaxial, when there are many modes of radiated waves, the intensity varies due to interference between the radiated waves. In order to avoid this, in a normal leaky coaxial cable, P and the slot arrangement are devised so that only m = −1 exists (see the above-mentioned reference). Also in this embodiment, a single mode of m = −1 is used using this conventional technique.

  The communication terminal 220-1 is connected to the direct wave receiving unit 140-1 and the reflected wave receiving unit 150-1 of the base station 100-1, and inputs and outputs signals. The LCX 200-1 is provided with a plurality of slots 230 (slot 230-1, slot 230-2, slot 230-3,...) That are radiation holes as described above. The reflection end 210-1 is configured to reflect a signal propagating through the LCX 200-1. The reflection end 210-1 is, for example, an open end. For example, it is good also as a structure provided with a radio signal reflecting device. Alternatively, a termination resistor may be connected, and the termination resistor may be removed and open termination only when position detection is performed.

The mobile terminal 300-1 is, for example, a terminal carried by the user. In this embodiment, the mobile terminal 300-1 includes a signal transmission unit 340-1, a wireless communication unit 350-1, a position display map information reception unit 360-1, and a display. Part 370-1.
The signal transmission unit 340-1 outputs an electric signal for detecting the position of the mobile terminal 300-1 in the space by the LCX 200-1. Here, the electrical signal is information that allows the base station 100-1 to measure the time interval, and the signal transmission unit 340-1 transmits a signal that can identify the time information. When transmitting electrical signals multiple times or continuously transmitting them, it is possible to identify whether they are due to the same electrical signal by comparing the time information indicated by the direct wave and the reflected wave. Can do. Further, whether the direct wave and the reflected wave are due to the same electric signal, for example, includes identification information in the header of an information packet output as an electric signal, and the base station 100-1 determines this identification information. May be compared to determine the correspondence.

The radio communication unit 350-1 performs radio communication with the base station 100-1 using a frequency band different from that of the signal transmission unit 340-1. For example, the wireless communication unit 350-1 performs wireless communication with a mobile terminal such as mobile phone communication or a notebook PC (Personal Computer) or PDA (Personal Digital Assistant).
The position display map information receiving unit 360-1 receives the position display map information transmitted from the position display map information transmitting unit 160-1. The display unit 370-1 is a display using liquid crystal or the like, and displays position display map information received by the position display map information receiving unit 360-1.

Next, the operation principle of position detection according to this embodiment will be described. The position detection according to the present embodiment is based on a TOA (Time Of Arrival) method in which a distance is determined based on a time at which a signal reaches another point from a specific point.
As shown in FIG. 4, the signal output from the mobile terminal 300 into the space and received by the LCX 200 arrives at the communication end 220 at the same time when the mobile terminal 300 is at the points A and B. That is, since the location of the mobile terminal 300 where the arrival time of the signal arrives at the base station 100 is the same as the sum of the signal propagation time in space and the signal propagation time in the LCX 200, the signal is sent to the base station 100. The locations in the space where the two arrive at the same time form a line L (L1, L2, L3) as shown in FIG. In other words, the position cannot be specified even if the arrival time of only the direct wave is measured.

  Therefore, the reflected wave reflected by the reflection end 210 of the LCX 200 is also used for measurement. That is, as shown in FIG. 5, the extending direction in which the LCX 200 is laid is defined as the X axis, the LCX 200 and the vertical direction are defined as the Y axis, and the position of the mobile terminal 300 is determined by the value of the position x in the X direction and the position y in the Y direction. , X can be calculated as the difference between the arrival time of the direct wave and the arrival time of the reflected wave, and y can be calculated as the direct wave after the signal is output from the mobile terminal 300. It can be calculated as the sum of the time until the signal with the reflected wave is received.

That is, as shown in FIG. 6, the shorter the arrival interval between the direct wave and the reflected wave, the closer the position of the mobile terminal 300 is to the reflection end 210. This is because the direct wave is received by the LCX 200 and arrives at the base station 100, and then the signal is reflected by the reflection end 210, and it can be said that the distance traveled until the reflected wave arrives at the base station 100 is short.
Further, as illustrated in FIG. 7, the longer the time from when the mobile terminal 300 outputs a signal until the direct wave reaches the base station 100, the longer the mobile terminal 300 is away from the LCX 200. Based on the above, when each value is defined as shown in FIG. 8, the following equation (3) is established.

  When this is solved as in the following formula (4), the following formula (1) is derived.

Thus, according to equation (1) described above, by giving the direct wave arrival time (t _1), the arrival time of the reflected wave and a (t ₂₎ as a parameter, to calculate the position of the mobile terminal 300 be able to. The calculation unit 120 calculates the position of the mobile terminal 300 according to the above equation (1).

<First Embodiment: Operation>
Next, with reference to FIG. 9, an operation example in which the position detection system according to the present invention calculates position information of the mobile terminal 300-1 will be described.
As described above, the map information storage unit 180-1 stores map information as shown in FIG. 20 in advance.
First, the signal transmission part 340-1 of the mobile terminal 300-1 outputs a signal in space (step S10). The signal is received by the slot 230-1 and propagates as a direct wave in the LCX 200-1. (Step S20). When receiving the direct wave, the direct wave receiving unit 140-1 of the base station 100-1 stores the reception time as the direct wave reception time information. The signal received in the slot 230-2 propagates in the LCX 200-1, is reflected by the reflection end 210-1, and is received as a reflected wave by the reflected wave receiving unit 150-1 of the base station 100-1. (Step S30).

  When receiving the reflected wave, the reflected wave receiving unit 150-1 of the base station 100-1 stores the reception time as reflected wave reception time information. Upon receiving the time information, the calculation unit 120-1 of the base station 100-1 calculates the value of the estimated X coordinate value and the estimated Y coordinate value as position information using the above-described equation (1) (step S40). ). And the position display map information generation part 190-1 reads the map information memorize | stored in the map information storage part 180-1, and it is a star on the position on the map information corresponding to the position information which the calculation part 120-1 calculated. The position display map information with the mark added is generated. The position display map information transmission unit 160-1 transmits the position display map information generated by the position display map information generation unit 190-1 to the mobile terminal 300-1 (step S50). When the position display map information receiving unit 360-1 receives the position display map information, the display unit 370-1 displays the received position display map information.

Further, the position display map information generated by the position display map information generation unit 190-1 may be displayed on the display unit 170-1 of the base station 100-1, or may be transmitted to an external server.
As described above, according to the present embodiment, the mobile terminal 300-1 can perform position detection only by including the signal transmission unit 340-1, and the mobile terminal 300-1 may be an inexpensive terminal. The position detection can be performed with low power consumption.
Such a position detection system is particularly used when, for example, a fire brigade member who performs work in a building or underground, carries the mobile terminal 300-1, and the fire brigade commander on the ground grasps the location information of the fire brigade member. It is valid.

<Second Embodiment: Configuration>
The base station 100 may be configured to output the position detection signal output from the signal transmission unit 340-1 of the mobile terminal 300-1 in the first embodiment. FIG. 10 is a diagram illustrating the concept of the position detection system according to the second embodiment. A signal transmitted from the base station 100 to the LCX 200 via the communication terminal 220 propagates along the line of the LCX 200, is radiated at a specific angle θ with respect to the traveling direction, and arrives at the mobile terminal 300 as a direct wave. . Furthermore, the signal propagating through the LCX 200 is reflected by the reflection end 210, is radiated at an angle θ determined with respect to the traveling direction, like the direct wave, and arrives at the mobile terminal 300 as a reflected wave. The mobile terminal 300 receives the arrival signals of these two paths, and detects the two-dimensional position based on the propagation time or the propagation time difference between the direct wave and the reflected wave. Note that the present invention can also be applied when a signal is transmitted from the mobile terminal 300.

  The position detection system according to the second embodiment has the same configuration as that of the first embodiment, and the description of the same configuration and processing is omitted. Hereinafter, the configuration and processing unique to the second embodiment will be described. FIG. 11 is a block diagram showing the configuration of the position detection system according to the present embodiment. The position detection system according to the present embodiment includes a base station 100-2, an LCX 200-2, and a mobile terminal 300-2.

  The base station 100-2 is a communication base station that communicates with the mobile terminal 300-2 via the LCX 200-2, and includes a signal transmission unit 130-2 and a map information storage unit 180-2. The signal transmission unit 130-2 is connected to the communication end 220-2 of the LCX 200-2 and inputs / outputs signals with the communication end 220-2. Moreover, the signal transmission part 130-2 transmits the map information memorize | stored in the map information storage part 180-2 with the signal for detecting a positional information to the mobile terminal 300-2.

The mobile terminal 300-2 is a terminal carried by the user, and includes a direct wave receiving unit 320-2, a reflected wave receiving unit 330-2, a wireless communication unit 350-2, a display unit 370-2, and a calculation. Unit 380-2 and a position display map information generation unit 390-2.
The calculation unit 380-2 includes direct wave time information indicating the time when the direct wave receiving unit 320-2 receives the direct wave and reflected wave time information indicating the time when the reflected wave receiving unit 330-2 receives the reflected wave. Based on this, position information indicating the position of the mobile terminal 300-2 is calculated.

<Second Embodiment: Operation>
Next, with reference to FIG. 12, an operation example in which the position detection system according to the present invention calculates position information of the mobile terminal 300-2 will be described.
First, the signal transmission unit 130-2 of the base station 100-2 outputs the map information stored in the map information storage unit 180-2 and a signal for detecting the position to the communication terminal 220-2 (step). S110). Here, the signal transmission unit 130-2 may further transmit a calculation algorithm for detecting a position on the map information from the coordinate position information. And the information output from the signal transmission part 130 propagates in LCX200-2. Then, a direct wave is radiated from the slot 231-1 at an angle θ (step S120). When the direct wave receiver 320-2 of the mobile terminal 300-2 receives a direct wave, the reception time is stored as direct wave reception time information. The signal propagating in the LCX 200-2 is reflected by the reflection end 210-2, and a reflected wave is radiated from the slot 231-2 at an angle θ (step S130).

Then, when the reflected wave reception unit 330-2 of the mobile terminal 300-2 receives the reflected wave, the reception time is stored as reflected wave reception time information. And the calculation part 380-2 uses the above-mentioned Formula (1) based on the time information of direct wave reception time information and reflected wave reception time information, and the value of an estimated X coordinate value and an estimated Y coordinate value. Is calculated as position information (step S140). And the position display map information generation part 390-2 reads the map information transmitted from the signal transmission part 130-2 with the signal for detecting a position, and the map corresponding to the position information which the calculation part 120-1 calculated The position display map information with the star added to the position on the information is generated.
The position display map information generated by the position display map information generation unit 390-2 is displayed on the display unit 370-2 of the mobile terminal 300-2.

Thus, according to the second embodiment, the base station 100-2 outputs an electrical signal, and the mobile terminal 300-2 is positioned based on the reception time of the direct wave and the reflected wave of the received electrical signal. Since the position display map information is generated by calculating the information, the time error is smaller than in the first embodiment in which the mobile terminal 300-1 receives the position information calculated by the base station 100-1.
Such a position detection system is particularly effective when, for example, a fire brigade carries the mobile terminal 300-2 and confirms his / her position information inside a building or underground.

<Third Embodiment: Configuration>
In the third embodiment, the mobile terminal 300-3 receives an electrical signal output from the base station 100-3, transmits the received time information to the base station 100-3, and the base station 100-3 Information is calculated.
The position detection system according to the third embodiment has the same configuration as that of the second embodiment, and the description of the same configuration and processing is omitted. Hereinafter, the configuration and processing unique to the third embodiment will be described. FIG. 13 is a block diagram showing the configuration of the position detection system according to this embodiment. The position detection system according to the present embodiment includes a base station 100-3, an LCX 200-3, and a mobile terminal 300-3.

  The base station 100-3 is a communication base station that communicates with the mobile terminal 300-3 via the LCX 200-3, and includes a time information reception unit 110-3, a calculation unit 120-3, and a signal transmission unit 130-3. And a position display map information transmission unit 160-3 and a map information storage unit 180-3. The time information receiving unit 110-3 includes time information transmitted from the mobile terminal 300-3, that is, direct wave time information for the mobile terminal 300 to receive a direct wave from the LCX 200-3 and reflected wave time information for receiving a reflected wave. The time information including is received.

The calculation unit 120-3 calculates position information indicating the position of the mobile terminal 300-3 based on the direct wave time information and the reflected wave time information received by the time information reception unit 110-3 from the mobile terminal 300-3. To do.
The signal transmission unit 130-3 is connected to the communication end 220-3 of the LCX 200-3 and inputs / outputs signals with the communication end 220-3.

The mobile terminal 300-3 is, for example, a terminal carried by the user, and includes a direct wave receiving unit 320-3, a reflected wave receiving unit 330-3, a time information transmitting unit 310-3, and a wireless communication unit 350-. 3, a position display map information receiving unit 360-3, and a display unit 370-3. The direct wave receiving unit 320-3 has an angle θ from the slot 232 (for example, the slot 232-1) of the LCX 200-3. The reflected wave receiving unit 330-3 receives the reflected wave radiated at an angle θ from the slot 232 (for example, the slot 232-2) of the LCX 200-3. The time information transmitting unit 310-3 includes direct wave time information that is time information when the direct wave receiving unit 320-3 receives a direct wave, and reflection that is time information when the reflected wave receiving unit 330-3 receives a reflected wave. Time information including wave time information is transmitted to the base station 100-3.

<Third Embodiment: Operation>
Next, with reference to FIG. 14, an example of an operation in which the position detection system according to the present invention calculates position information of the mobile terminal 300 will be described.
First, the signal transmission unit 130-3 of the base station 100-3 outputs a signal to the communication terminal 220-3 (step S210). Then, the signal propagates through the LCX 200-3. Then, a direct wave is radiated from the slot 232-1 at the angle θ (step S220). When the direct wave receiving unit 320-3 of the mobile terminal 300-3 receives a direct wave, the reception time is stored as direct wave reception time information. The signal propagating in the LCX 200-3 is reflected by the reflection end 210-3, and a reflected wave is emitted from the slot 232-2 at an angle θ (step S230).

  Then, when the reflected wave receiving unit 330-3 of the mobile terminal 300-3 receives the reflected wave, the reception time is stored as reflected wave reception time information. And the time information transmission part 310-3 transmits the time information of direct wave reception time information and reflected wave reception time information to the base station 100-3 (step S240). When receiving the time information, the time information receiving unit 110-3 of the base station 100-3 calculates the value of the estimated X coordinate value and the estimated Y coordinate value as position information using the above-described equation (1) ( Step S250).

And the position display map information generation part 190-3 reads the map information memorize | stored in the map information storage part 180-3, and a star on the position on the map information corresponding to the position information which the calculation part 120-1 calculated. The position display map information with the mark added is generated. The position display map information transmission unit 160-3 transmits the position display map information generated by the position display map information generation unit 190-3 to the mobile terminal 300-3 (step S260). When the position display map information receiving unit 360-3 of the mobile terminal 300-3 receives the position display map information, the position display map information is displayed on the display unit 370-3.
Further, the position display map information generated by the position display map information generation unit 190-3 may be displayed with a display unit provided in the base station 100-3, for example, or may be transmitted to an external server. .

  As described above, according to the present embodiment, the arrival time when the direct wave that is a signal propagated in the space from the communication end 220-3 via the LCX 200-3 arrives at the mobile terminal 300-3, and the same signal By using, as a parameter, the arrival time when the reflected wave arrives at the mobile terminal 300-3 after being reflected by the reflection end 210-3 which is the other end of the communication end 220-3 of the LCX 200-3 It is possible to detect and calculate the two-dimensional position of the mobile terminal 300-3 by a single frequency using a coaxial cable.

<Other embodiments>
As shown in FIG. 15, the reflection end 210 described above may be configured by a circulator 211, a band filter 212, and an absorption resistor 213. That is, the end of the LCX 200 is connected to the first terminal of the circulator 211, and the second terminal of the circulator 211 is connected to the bandpass filter 212 and the absorption resistor 213. The other end of the band filter 212 is connected to the third terminal of the circulator 211. Here, the band filter 212 is set in advance so as to pass only the signal for position detection.
If comprised in this way, the reflective end 210 will reflect only the signal for a position detection, for example, can perform position detection, using LCX200 together as an antenna for communication of a mobile telephone. .

  As shown in FIG. 16, the position detection according to the present invention can also be applied to the case where the LCX 200 is laid on a winding road such as an underground shopping street.

<Example of the present invention>
FIG. 17 shows an environment in which a position detection experiment based on the position detection principle of the present invention was performed. Two-dimensional coordinates are set so that the black point in the figure is the measurement point, and the lower left of the figure (the intersection of X and Y) is the origin, so that the horizontal direction in the figure is the X axis and the vertical direction is the Y axis I made it. The LCX is 5m long and 1.4m above the floor, uses a non-directional antenna as the receiving antenna of the mobile terminal, and always uses the tripod and is always the same height as the LCX. I tried to become. The impulse response between the communication end and the mobile terminal was measured using a weak 2.4 GHz band radio wave.

FIG. 18 is a waveform diagram showing a measurement example of an impulse response in this experiment of the network analyzer. The times t ₁ and t ₂ when the amplitude ratio of the direct wave or the reflected wave in the figure becomes the maximum are taken as the arrival times.
In such an experiment, the arrival time t ₁ of the direct wave and the arrival time difference t ₂ of the direct wave and the reflected wave were measured with an omnidirectional antenna. t ₁ and t ₂ were substituted into Equation (1), and the estimated position for each measurement point was calculated. FIG. 19 shows an error distribution of the calculation result. A position detection error of about 0.25 m or less was obtained by t ₁ and t ₂ obtained from observation of the average impulse response 16 times at each measurement point. In this way, by combining the two mathematical formulas of the arrival time of the direct wave and the arrival time of the reflected wave, position detection can be performed with high accuracy in an area where the radiation ranges of the direct wave and the reflected wave overlap. I was able to confirm. Here, the closer to the center of the LCX, the higher the accuracy of the result.

  In this way, for a method of detecting a two-dimensional position of a mobile terminal using a single frequency using a single LCX, error dispersion is observed in a position detection experiment, and a position detection error of 25 cm or less is detected. It turns out that it can be realized.

  It should be noted that a program for realizing the function of the processing unit in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed for position detection. May be. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

It is a figure which shows the position detection system by the 1st Embodiment of this invention. 1 is a block diagram showing a position detection system according to a first embodiment of the present invention. It is a figure which shows the structure of LCX by embodiment of this invention. It is a figure which shows the principle of the position detection by embodiment of this invention. It is a figure which shows the principle of the position detection by embodiment of this invention. It is a figure which shows the principle of the position detection by embodiment of this invention. It is a figure which shows the principle of the position detection by embodiment of this invention. It is a figure which shows the principle of the position detection by embodiment of this invention. It is a sequence diagram which shows the operation example by the 1st Embodiment of this invention. It is a figure which shows the position detection system by the 2nd Embodiment of this invention. It is a block diagram which shows the position detection system by the 2nd Embodiment of this invention. It is a sequence diagram which shows the operation example by the 2nd Embodiment of this invention. It is a block diagram which shows the position detection system by the 3rd Embodiment of this invention. It is a sequence diagram which shows the operation example by the 3rd Embodiment of this invention. It is a figure which shows the reflective end by embodiment of this invention. It is a figure which shows the position detection system by embodiment of this invention. It is a figure which shows the experimental environment of the position detection system of this invention. It is a figure which shows the amplitude ratio of the electric signal by experiment of the position detection system of this invention. It is a figure which shows distribution of the error of the experimental measurement result of the position detection system of this invention. It is a figure which shows the example of the map information by embodiment of this invention. It is a figure which shows the example of the position display map information by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Base station 110 Time information receiving part 120 Calculation part 130 Signal transmission part 140 Direct wave receiving part 150 Reflected wave receiving part 160 Position display map information transmission part 170 Display part 180 Map information storage part 190 Position display map information generation part 200 LCX
210 Reflecting end 211 Circulator 212 Band filter 213 Absorption resistor 220 Communication end 230 Slot 291 Sheath 292 Outer conductor 293 Insulator 294 Inner conductor 300 Mobile terminal 310 Time information transmitting unit 320 Direct wave receiving unit 330 Reflected wave receiving unit 340 Signal transmitting unit 350 Wireless communication unit 360 Location display map information reception unit 370 Display unit 380 Calculation unit 390 Location display map information generation unit

Claims (8)

A position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna,
The leaky coaxial cable is
A communication end that is a terminal connected to the base station so as to output an electric signal to the base station, and an other end that is configured to reflect an electric signal propagating through the own cable. A reflection end comprising a bandpass filter for reflecting only the frequency band of the electrical signal,
The mobile terminal
Comprising signal transmission means for transmitting the electrical signal to the leaky coaxial cable;
The base station
An electric signal transmitted from the mobile terminal and received by the leaky coaxial cable, and received directly from the leaky coaxial cable to the communication end without being reflected by the reflection end. Wave receiving means;
Reflected wave receiving means for receiving a reflected wave that is an electric signal input to the communication end after being reflected by the reflection end of the leaky coaxial cable;
Based on the direct wave reception time information indicating the time when the direct wave receiving means receives the direct wave and the reflected wave reception time information indicating the time when the reflected wave receiving means receives the reflected wave, the mobile terminal A position detecting system comprising: a calculating means for calculating the position information of the position. A position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna,
The leaky coaxial cable is
A communication end that is a terminal connected to the base station so that an electric signal is input from the base station;
A second end configured to reflect an electric signal propagating inside the own cable, and a reflection end including a bandpass filter for reflecting only a predetermined frequency band of the electric signal, and
The mobile terminal
Direct wave receiving means for receiving a direct wave radiated from the leaky coaxial cable into the space before being reflected at the reflection end by an electrical signal output from the base station via the communication end to the leaky coaxial cable. When,
Reflected wave receiving means for receiving a reflected wave radiated into the space from the leaky coaxial cable by an electrical signal after being reflected by the reflection end of the leaky coaxial cable;
Based on the direct wave reception time information indicating the time when the direct wave receiving means receives the direct wave and the reflected wave reception time information indicating the time when the reflected wave receiving means receives the reflected wave, Calculating means for calculating position information,
The base station
A position detection system comprising: signal transmission means connected to the communication end of the leaky coaxial cable and transmitting the electric signal to the mobile terminal via the leaky coaxial cable. A position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna,
The leaky coaxial cable is
A communication end that is a terminal connected to the base station so that an electric signal is input from the base station;
A second end configured to reflect an electric signal propagating inside the own cable, and a reflection end including a bandpass filter for reflecting only a predetermined frequency band of the electric signal, and
The mobile terminal
Direct wave receiving means for receiving a direct wave radiated from the leaky coaxial cable into the space before being reflected at the reflection end by an electrical signal output from the base station via the communication end to the leaky coaxial cable. When,
Reflected wave receiving means for receiving a reflected wave radiated into the space from the leaky coaxial cable by an electrical signal after being reflected by the reflection end of the leaky coaxial cable;
Generating time information including direct wave reception time information indicating a time when the direct wave receiving unit receives the direct wave and reflected wave reception time information indicating a time when the reflected wave receiving unit receives the reflected wave; And time information transmitting means for transmitting to the base station,
The base station
A signal transmitting means connected to the communication end of the leaky coaxial cable and transmitting the electrical signal to the mobile terminal via the leaky coaxial cable;
Time information receiving means for receiving time information transmitted from the time information transmitting means;
A position detection system comprising: calculation means for calculating position information of the mobile terminal based on the direct wave reception time information detected from the time information and the reflected wave time information. The calculation means includes an X-axis value and a Y-coordinate value in two-dimensional coordinates when the leaky coaxial cable is an X-axis, a direction perpendicular to the X-axis is a Y-axis, and the communication end is a coordinate origin. Where the X coordinate is (X˜), the Y coordinate is (Y˜), the direct wave reception time information is t1, the reflected wave reception time information is t2, and the electrical power in the leaky coaxial cable is The propagation speed of the signal is v, the propagation speed of the electrical signal in space is c, the length of the leaky coaxial cable is l, and the electrical signal between the Y axis and the mobile terminal and the leaky coaxial cable as the angle between the propagation path of theta,

4. The position detection system according to claim 1, wherein the position information is calculated by calculating. A position detection method by a position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna,
Of the leaky coaxial cable,
A communication end, which is a termination, outputs an electrical signal to the base station;
A reflection end having a band-pass filter for reflecting only the predetermined frequency band of the electric signal at the other end, and a step of reflecting the electric signal propagating inside the own cable,
Of the mobile terminal,
A signal transmission means comprising the step of transmitting the electrical signal to the leaky coaxial cable;
Of the base station,
The direct wave receiving means is an electric signal transmitted from the mobile terminal and received by the leaky coaxial cable, and is an electric signal input from the leaky coaxial cable to the communication end without being reflected by the reflection end. Receiving a direct wave; and
A step of receiving a reflected wave that is an electric signal input to the communication end after the reflected wave receiving means reflects on the reflection end of the leaky coaxial cable;
Based on the direct wave reception time information indicating the time when the direct wave receiving means receives the direct wave and the reflected wave reception time information indicating the time when the reflected wave receiving means receives the reflected wave. And a step of calculating position information of the mobile terminal. A position detection method by a position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna,
Of the leaky coaxial cable,
A communication end, which is a termination, receiving an electrical signal from the base station;
A reflection end having a band-pass filter for reflecting only the predetermined frequency band of the electric signal at the other end, and a step of reflecting the electric signal propagating inside the own cable,
Of the mobile terminal,
The direct wave receiving means emits a direct wave radiated from the leaky coaxial cable into the space before being reflected at the reflection end by an electrical signal output from the base station to the leaky coaxial cable via the communication end. Receiving, and
A step of receiving a reflected wave radiated into the space from the leaky coaxial cable by the electrical signal after the reflected wave receiving means is reflected by the reflection end of the leaky coaxial cable;
The time information transmitting means includes direct wave receiving time information indicating a time when the direct wave receiving means receives the direct wave, and reflected wave receiving time information indicating a time when the reflected wave receiving means receives the reflected wave. Based on the step of calculating the location information of the mobile terminal,
Of the base station,
Signal transmitting means connected to the communication end of the leaky coaxial cable and transmitting the electrical signal to the mobile terminal via the leaky coaxial cable;
And a step of receiving time information transmitted from the time information transmitting means. A position detection method by a position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna,
Of the leaky coaxial cable,
A communication end, which is a termination, receiving an electrical signal from the base station;
A reflection end having a band-pass filter for reflecting only the predetermined frequency band of the electric signal at the other end, and a step of reflecting the electric signal propagating inside the own cable,
Of the mobile terminal,
The direct wave receiving means emits a direct wave radiated from the leaky coaxial cable into the space before being reflected at the reflection end by an electrical signal output from the base station to the leaky coaxial cable via the communication end. Receiving, and
A step of receiving a reflected wave radiated into the space from the leaky coaxial cable by the electrical signal after the reflected wave receiving means is reflected by the reflection end of the leaky coaxial cable;
The time information transmission means includes direct wave reception time information indicating a time when the direct wave reception means receives the direct wave, and reflected wave reception time information indicating a time when the reflected wave reception means receives the reflected wave. Generating time information including and transmitting to the base station,
Of the base station,
Signal transmitting means connected to the communication end of the leaky coaxial cable and transmitting the electrical signal to the mobile terminal via the leaky coaxial cable;
A time information receiving means for receiving time information transmitted from the time information transmitting means;
A calculating means comprising: calculating the position information of the mobile terminal based on the direct wave reception time information detected from the time information and the reflected wave time information. Method. A position detection system comprising a mobile terminal capable of wireless communication and a base station that performs wireless communication with the mobile terminal using a leaky coaxial cable as an antenna, wherein the leaky coaxial cable transmits an electrical signal to the base station. A communication end that is a terminal connected to the base station so as to output and an other end configured to reflect an electric signal propagating through the own cable, and only a predetermined frequency band of the electric signal The base station in the position detection system, comprising: a reflection end including a bandpass filter for reflecting the signal, wherein the mobile terminal includes signal transmission means for transmitting the electrical signal to the leaky coaxial cable,
An electric signal transmitted from the mobile terminal and received by the leaky coaxial cable, and received directly from the leaky coaxial cable to the communication end without being reflected by the reflection end. Wave receiving means;
Reflected wave receiving means for receiving a reflected wave that is an electric signal input to the communication end after being reflected by the reflection end of the leaky coaxial cable;
Based on the direct wave reception time information indicating the time when the direct wave receiving means receives the direct wave and the reflected wave reception time information indicating the time when the reflected wave receiving means receives the reflected wave, the mobile terminal Calculating means for calculating the position information of
A base station comprising:

Images