JP2006157117A - Mobile communication system - Google Patents

Abstract

An object of the present invention is to compensate for a Doppler frequency shift or antenna directivity shift, which is a hindrance to large-capacity communication with a fixed base station, even in a state where the vehicle is moving at high speed. Stable capacity communication.
In a mobile communication system in which a portable wireless terminal 2 used in a vehicle 1 performs large-capacity communication with a fixed base station 3 using first wireless communication means, first wireless communication means is provided. The position information of the fixed base station 3 is provided to the portable wireless terminal 2 by the second wireless communication means, and the position information of the vehicle 1 is provided to the portable wireless terminal 2 from the position information distribution device 4 installed in the vehicle 1. Communication is performed by correcting the Doppler frequency of the first wireless communication means by calculating the relative speed between the fixed base station 3 and the portable wireless terminal 2.
[Selection] Figure 1

Description

The present invention relates to a mobile communication system in which a portable wireless terminal can stably maintain a communication line with a fixed base station and perform large-capacity wireless data communication even in a state where the vehicle is traveling at a high speed. is there.

As a conventional mobile communication system, a portable wireless terminal carried in a moving body moving at high speed is installed in the moving body in order to perform stable communication with a fixed base station existing outside the moving body. There is a configuration for communicating with a fixed base station via a wireless or wired communication infrastructure (see, for example, Patent Documents 1 and 2). In addition, there is a configuration using azimuth recognition means such as GPS in order to adapt the directivity of the portable radio terminal antenna in the direction of the fixed base station (see, for example, Patent Document 3).

  FIG. 7 is a configuration diagram of a conventional mobile communication system described in Patent Document 1. The mobile communication system 1 includes a mobile base station 8 that uses the inside of the train 2 as a radio zone. By performing wireless communication with the mobile base station 8 installed in the vehicle, a communication line is established between the mobile base station 8 and the mobile communication switching center 7B via the relay cable 11. With such a configuration, the portable wireless terminal can be used even in a tunnel section, and a communication line with a connection partner can be reliably maintained even on a bullet train that moves at extremely high speed.

  FIG. 8 is a configuration diagram of a conventional mobile communication system described in Patent Document 2. A mobile terminal connection device 7 for connecting a mobile information terminal 9 brought in by a passenger and a mobile information terminal 9 are connected to a mobile body 4. A mobile communication server 5 that bundles communication lines established with the ground side and collectively performs wireless communication with the nearest fixed station 1 and a LAN 8 are installed, and the communication function of the mobile communication server 5 is used. The mobile information terminal 9 connected to the mobile terminal connection device 7 communicates with the fixed station 1. With such a configuration, a high quality communication line is secured, and a comfortable mobile computing environment such as efficient provision of information is provided.

FIG. 9 is a configuration diagram of a conventional mobile communication system described in Patent Document 3. A mobile terminal 100 includes a plurality of antenna elements 11 to 1n, a transmission / reception unit 10 having a directivity control function of the antenna elements, and a mobile terminal 100. And an azimuth sensor 20 for detecting the azimuth or inclination of the terminal. The transmission / reception unit 10 arbitrarily controls the directivity by giving different weights to the antenna elements 11 to 1n. A small sensor such as a gyro sensor, a capacitive acceleration sensor, a geomagnetic sensor, or a global positioning system (GPS) is used as the direction sensor 20, and the transmission / reception unit 10 rotates the mobile terminal obtained from the direction sensor 20, Based on the tilt or location information and map information, the antenna directivity is corrected in the direction of the base station. By adopting such a configuration, the antenna directivity of the mobile terminal is controlled in accordance with the direction of the mobile terminal and the movement of the tilt to provide a stable communication while maintaining a large gain in the direction of the base station.
JP 2002-335573 A JP-A-10-32262 Japanese Patent Laid-Open No. 2004-64741

However, in the configuration of Patent Document 1, since the mobile wireless terminal performs communication between the mobile base station installed in the vehicle and the fixed base station via the relay cable, stable large-capacity communication can be realized. A relay system must be built in the vehicle exclusively for this mobile communication system, and when supporting a plurality of mobile communication systems, a relay system corresponding to each system is required. is there.
Further, even in the configuration of Patent Document 2, since the mobile wireless terminal performs communication with the fixed base station via the mobile communication server installed in the vehicle and the LAN, stable large-capacity communication can be realized. Again, a dedicated relay system such as a mobile communication server must be built in the vehicle for the mobile communication system.

Further, in the configuration of Patent Document 3, since an existing mobile communication system is used, a dedicated relay system is unnecessary, but it is difficult for the portable wireless terminal to directly receive the GPS when boarding the vehicle. Since it cannot know its own position and cannot control the directivity of the antenna toward the base station, stable communication is difficult.
The present invention solves the above-described conventional problems, and can stably maintain a communication line between a portable wireless terminal and a base station even when the vehicle is on a high-speed moving vehicle, and can perform high-capacity wireless data communication. An object of the present invention is to provide a mobile communication system.

In order to solve the above-described conventional problems, the present invention provides a mobile communication system in which a portable wireless terminal used in a vehicle communicates with a fixed base station using a first wireless communication means. The position information of the fixed base station is provided to the portable wireless terminal by the wireless communication means, and the position information of the vehicle is transmitted from the position information distribution device installed in the vehicle to the portable wireless terminal by the second wireless communication means. The communication is performed by correcting a Doppler frequency of the first wireless communication means by calculating a relative speed between the fixed base station and the portable wireless terminal.

With this configuration, the position information of the portable wireless terminal can be acquired by a simple wireless communication infrastructure in the vehicle, and a Doppler frequency shift that becomes an obstacle to large-capacity communication with a fixed base station can be compensated.
Further, the present invention provides a mobile communication system in which a portable wireless terminal used in a vehicle communicates with a fixed base station using a first wireless communication means, and the fixed base station is connected with the first wireless communication means. Position information is provided to the portable wireless terminal, and position information of the vehicle is provided to the portable wireless terminal from a position information distribution device installed in the vehicle by a second wireless communication means, and the fixed base station and the A relative direction of the vehicle is calculated, and a relative direction between the fixed base station and the vehicle is calculated using position and direction recognition means of the mobile terminal in the vehicle, and the mobile radio terminal is moved in the direction of the fixed base station. It is characterized by directing the antenna directivity.

  With this configuration, it is possible to obtain relative position information between a portable wireless terminal and a fixed base station using a simple wireless communication infrastructure in the vehicle, and direct the antenna directivity toward the fixed base station so that the antenna directivity becomes an obstacle to large-capacity communication. Can compensate for gender deviation.

  Moreover, it is good also as a structure which uses the seat information of a train as a means to recognize the position of the said portable radio | wireless terminal in a vehicle.

With this configuration, it is possible to determine at which position the portable wireless terminal is arranged in the front / rear / left / right direction of the vehicle. Can be achieved. Furthermore, since it can be determined whether the mobile wireless terminal is located on the left or right side in the vehicle, the fixed base station on the side that is advantageous for wireless communication is selected from the left and right fixed base stations, and stable communication is performed. The effect of securing the line can be achieved.
Further, as means for recognizing the direction of the portable wireless terminal in the vehicle, a configuration may be adopted in which a user inputs and sets the traveling direction of the vehicle to the portable wireless terminal.
With this configuration, since the direction in which the fixed base station is disposed as seen from the mobile radio terminal side is uniquely determined, it becomes easier to direct the antenna directivity toward the base station side, and a stable communication line can be established. The effect of securing can be achieved.
In addition, the portable wireless terminal used in the mobile communication system of the present invention is configured to be able to communicate with the fixed base station by the first wireless communication means and the location information distribution device in which the vehicle is installed by the second wireless communication means. In the vehicle, means for receiving the position information of the fixed base station by the first wireless communication means, means for receiving the position information of the vehicle by the second wireless communication means from the position information distribution device, and the fixed base station And means for calculating the relative speed of the portable wireless terminal, and means for correcting and communicating the Doppler frequency of the first wireless communication means.

With this configuration, the position information of the portable wireless terminal can be acquired by a simple wireless communication infrastructure in the vehicle, and a Doppler frequency shift that becomes an obstacle to large-capacity communication with a fixed base station can be compensated.
In addition, the portable wireless terminal used in the mobile communication system of the present invention is configured to be able to communicate with the fixed base station by the first wireless communication means and the location information distribution device in which the vehicle is installed by the second wireless communication means. Means for receiving the position information of the fixed base station from the fixed base station by the first wireless communication means, and means for receiving the position information of the vehicle by the second wireless communication means from the position information distribution device in the vehicle; The direction of the fixed base station based on the direction calculated by the means for calculating the relative direction between the fixed base station and the vehicle, the means for receiving or inputting the terminal position and direction recognition information in the vehicle, and the means for calculating the direction Means for controlling the antenna directivity to the

  With this configuration, it is possible to obtain relative position information between a portable wireless terminal and a fixed base station using a simple wireless communication infrastructure in the vehicle, and direct the antenna directivity toward the fixed base station so that the antenna directivity becomes an obstacle to large-capacity communication. Can compensate for gender deviation.

According to the present invention, a relative speed and a relative direction of a portable wireless terminal with a fixed base station are calculated by a simple wireless communication infrastructure in a vehicle, and a Doppler frequency shift or an obstacle to large-capacity communication with the fixed base station is calculated. Since the antenna directivity shift can be compensated, the communication line with the base station can be stably maintained even in a state where the vehicle is moving at a high speed, and large-capacity wireless data communication can be performed.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 shows a configuration diagram of the mobile communication system according to the first embodiment of the present invention. The mobile communication system in FIG. 1 includes a fixed base station 4, a vehicle 1, a portable wireless terminal 2 and a position information distribution device 4 in the vehicle 1, and a vehicle external antenna 5. The portable radio terminal 2 includes a first antenna unit 6, a first radio circuit unit 7, a second antenna unit 8, a second radio circuit unit 9, a Doppler frequency calculation unit 10, a frequency correction unit 11, and the like. ing. Specifically, the vehicle 1 is intended for a vehicle such as a train, a bullet train, a monorail, a passenger car, a bus, etc., on which a passenger having the portable wireless terminal 2 rides and moves on land.

The mobile communication system shown in FIG. 1 is for the purpose of allowing a portable wireless terminal 2 in a moving vehicle 1 to perform large-capacity data communication with a fixed base station 3 using a first wireless communication means. Yes. In FIG. 1, the position information distribution device 4 acquires the position information of the vehicle 1 from the vehicle external antenna 5 and distributes it to the portable wireless terminal 2 using the second wireless communication means. The portable radio terminal 2 is provided with a first antenna unit 6 and a first radio circuit unit 7, and communicates with the fixed base station 3 using the first radio communication means. Get location information. The second antenna unit 8 and the second wireless circuit unit 9 arranged in the portable wireless terminal 2 acquire the position information of the vehicle 1 distributed from the position information distribution device 4. In the portable radio terminal 2, a Doppler frequency calculation unit 10 is connected to the first radio circuit unit 7 and the second radio circuit unit 9, and temporal information of the position information of the fixed base station 3 and the position information of the vehicle 1 is obtained. The relative movement speed and the Doppler frequency are obtained by obtaining a simple difference. Based on the calculation result of the Doppler frequency calculation unit 10, the frequency correction unit 11 is configured to compensate the frequency of the first radio circuit unit 7. As a result, it is possible to compensate for a Doppler frequency shift that becomes an obstacle to large-capacity communication with a fixed base station.
Next, the operation of the first embodiment will be described. FIG. 2 is a flowchart of the mobile communication system according to the first embodiment of the present invention. The position information of the fixed base station 3 acquired by the first radio circuit unit 7 and the position information of the vehicle 1 acquired by the second radio circuit unit 9 are input to the Doppler frequency calculation unit 10. The Doppler frequency calculation unit 10 calculates the relative movement speed of the vehicle 1 by obtaining a temporal difference between the position information of the fixed base station 3 and the position information of the vehicle 1. The procedure for calculating the relative movement speed will be described later with reference to FIG.

  Further, the Doppler frequency calculation unit 10 obtains the Doppler frequency from the relative movement speed and the operating frequency of the first wireless communication means, and outputs it to the frequency correction unit 11. The frequency correction unit 11 performs frequency shift control on the first radio circuit unit 7 through control such as operating the frequency control voltage of the reference signal transmitter, and corrects a transmission / reception frequency shift caused by high-speed movement. .

Next, the procedure for calculating the Doppler frequency will be described. FIG. 3 is a conceptual diagram of Doppler frequency shift calculation of the mobile communication system according to Embodiment 1 of the present invention.
The coordinates of the fixed base station 3 are (X0, Y0), the coordinates of the observation point A are (XA, YA), the coordinates of the observation point B are (XB, YB), and the vehicle 1 is from the observation point A to the observation point B. It takes time Δt to move. Assuming that the relative distance between the fixed base station 3 and the observation point A is ΔA, and the relative distance between the fixed base station 3 and the observation point B is ΔB, they are obtained by (Equation 1) and (Equation 2), respectively.

The relative movement distance when the vehicle 1 moves from the observation point A to the observation point B is ΔLB−ΔLA.
If it takes time Δt during this time, the relative movement speed ΔV is given by (Equation 3).

Given in. The Doppler frequency ΔfD [Hz] generated at this time is as follows, assuming that the communication frequency is f [Hz] and the speed of light is c = 3 × 10 ⁸ [m / s].

As described above, the Doppler frequency ΔfD [Hz] can be calculated from (Equation 1) to (Equation 4).
For example, when the communication frequency f is 2 GHz, the vehicle moves at a constant speed over 100 seconds from point A (1000,0) 1 km away from the fixed base station (0,0) to point B (1000,1000). In this case, the speed of the vehicle is 10 m / s, but the relative movement speed is 4.14 m / s, and the Doppler frequency ΔfD = −55.2 Hz. For this reason, frequency deviation can be compensated by performing communication with the communication frequency f lowered from 2 GHz to 55.2 Hz.
In FIG. 1, GPS, a quasi-zenith satellite system, a train operation system, or VICS information can be used as means for the position information distribution device 4 to recognize the position information of the vehicle 1 in real time. These position information confirmation means are widely used as existing position recognition systems, and it is not necessary to construct a new position recognition system for the mobile communication system. Furthermore, in-vehicle devices for these position recognition systems are often installed in the vehicle 1, and the operation can be achieved at a low cost simply by adding a device for the second wireless means as a unit.

  In addition, as a second wireless communication means that is a means for transmitting the position information of the vehicle 1 to the portable wireless terminal 2, short-range wireless communication such as wireless LAN, Bluetooth (registered trademark), infrared communication, TV, FM, AM, etc. Broadcast waves and the like can be used. These wireless communication means are often installed as an additional function in the existing portable wireless terminal 2, and it is not necessary to construct a new wireless communication means for the mobile communication system. For this reason, even if a new wireless circuit is not added to the portable wireless terminal 2, it can be realized at low cost. In addition, since the location information only needs to be distributed to the mobile wireless terminal 2, broadcast waves such as TV, FM, and AM are used, even if the communication information is not bidirectional communication means such as a wireless LAN or Bluetooth (registered trademark). Is feasible. Further, these second communication means only need to be used only inside the vehicle 1 and may have a communication distance of several meters to several tens of meters. Therefore, the second antenna unit 8 mounted on the portable wireless terminal 2 is small. Simple and easy to use and convenient to carry.

  Also, since the relative movement speed changes from moment to moment depending on the effective speed of the vehicle, the direction of travel, and the relative relationship with the base station, the calculation of the relative movement speed of the vehicle 1 and the deviation of the transmission / reception frequency are guaranteed in real time. It is desirable to do. In practice, it is ideal to perform at an interval equivalent to the time interval at which the position information of the vehicle 1 is provided. However, when the relative speed is not changed with time, the frequency control interval is increased or constant. You can also pause for hours. By doing so, current consumption for control can be saved.

  In addition, the position information of the fixed base station 3 does not change until the first communication means is handed over to the next fixed base station, so the same information is used as long as the fixed base station 3 in communication does not change. Location information can be used. With this configuration, current consumption for control can be saved.

When the relative movement speed is small and the Doppler frequency is smaller than a certain value, it can be determined that there is no problem in communication. Therefore, the frequency shift control operation of FIG. The AFC (automatic frequency control function) mounted on the circuit unit 7 may be interrupted. With this configuration, current consumption for control can be saved.
Further, regarding the position information of the fixed base station 3 to be communicated next, the traveling direction is calculated from the time change of the position information of the vehicle 1, the position information of the fixed base station 3 existing in the traveling direction of the vehicle 1 in advance, Communication frequency information can be transmitted to the portable wireless terminal 2. In this way, the handover process to the base station to be moved next can be performed at high speed.
In addition, when the first wireless communication means needs to establish synchronization between the uplink and the downlink, the Doppler frequency calculation unit 10 determines the temporal change in the relative movement speed and the synchronization frequency of the first wireless communication means. The median value of the synchronization deviation is obtained from the above and output to the frequency correction unit 11. The frequency correction unit 11 performs synchronization timing control on the first radio circuit unit 7 by controlling the synchronization pull-in timing of the demodulator by an amount corresponding to the synchronization shift, and corrects the synchronization shift due to high-speed movement. It is also possible.
(Embodiment 2)
Next, a mobile communication system according to Embodiment 2 of the present invention will be described with reference to the drawings.

FIG. 4 shows a configuration diagram of the mobile communication system in the second embodiment. In FIG. 4, the same reference numerals are assigned to the same contents as those in FIG. 1, and descriptions of the same contents as those in FIG. 1 are omitted. In FIG. 4, the position and orientation recognition unit 12 of the portable wireless terminal is connected to the portable wireless terminal 2, and the portable wireless terminal 2 has a relative direction calculation unit 13 and an antenna directivity correction unit 14. 4, the position information distribution device 4, the vehicle external antenna 5, the first antenna unit 6, the first radio circuit unit 7, the second antenna unit 8, and the second radio circuit unit 9 are the same as those in FIG. It has a similar function. A relative direction calculation unit 13 is connected to the first radio circuit unit 7 and the second radio circuit unit 9 to obtain position information of the fixed base station 3 and relative position information of the vehicle 1. Further, a terminal position and orientation recognition unit 12 is connected to the relative direction calculation unit 13, and a fixed base station viewed from the mobile radio terminal 2 based on information on relative position information, terminal position information in the vehicle, and terminal orientation. Determine the orientation of 3. The relative orientation information from the terminal position and orientation recognition means 12 is input to the antenna directivity correction unit 14 so that the antenna directivity is directed to the fixed base station side. Thereby, it is possible to compensate for the antenna directivity shift that becomes an obstacle to the large-capacity communication.
Next, the operation of the second embodiment will be described. FIG. 5 is a flowchart of the mobile communication system according to Embodiment 2 of the present invention.

The position information of the fixed base station 3 acquired by the first radio circuit unit 7 and the position information of the vehicle 1 acquired by the second radio circuit unit 9 are input to the relative direction calculation unit 13. Further, a terminal position and orientation recognition unit 12 is connected to the relative direction calculation unit 13, and terminal position information and terminal orientation information in the vehicle are input. The relative direction calculation unit 13 determines the orientation of the fixed base station 3 viewed from the mobile radio terminal 2 based on the location information of the fixed base station 3, the location information of the mobile radio terminal 2, the location information of the terminal in the vehicle, and the orientation of the terminal. decide. The procedure for calculating the relative orientation will be described later with reference to FIG. Relative azimuth information from the relative direction calculation unit 13 is input to the antenna directivity correction unit 14. The antenna directivity correction unit 14 controls the antenna directivity with respect to the first radio circuit unit 7 by controlling the weighting function of the first antenna unit 6, and the like. Correct the gender gap.
Next, the relative azimuth calculation procedure of the second embodiment will be described. FIG. 6 is a conceptual diagram of relative direction calculation of the mobile communication system according to the second embodiment of the present invention.
The coordinates of the fixed base station 3 are (X0, Y0), the coordinates of the observation point A are (XA, YA), the coordinates of the observation point B are (XB, YB), and the vehicle 1 is from the observation point A to the observation point B. Shall move. When the base station orientation of the fixed base station viewed from the observation point A is Direction A, and the base station orientation of the fixed base station 3 viewed from the observation point B is Direction B, (Equation 5) and (Equation 6) are obtained, respectively.

Further, in each observation point, when the terminal faces in the ΦT direction, the directions of the fixed base station viewed from the terminal are (Expression 7) and (Expression 8).

The relative amount of change ΔΦ that occurs when the vehicle 1 moves from the observation point A to the observation point B is given by (Equation 9).

As described above, the change amount ΔΦ in the base station relative direction can be calculated from (Equation 9). For example, in the direction of viewing the fixed base station (0,0) from point A (1000,0) and the direction of viewing the fixed base station (0,0) from point B (1000,1000) The amount of change is π / 4 = 45 °. For this reason, the directivity shift can be compensated by performing communication by changing the antenna directivity by 45 ° while moving from the point A to the point B. By the way, if the directivity change of 45 ° is performed only by one control as in this example, communication may be interrupted before the control due to a deviation from the directivity of the antenna, so ΔΦ is about several degrees. It is desirable to compensate for the directivity shift at intervals.

  In FIG. 4, the vehicle is sufficiently small as in the case of a short train or a passenger car, and the position of the terminal in the vehicle is substantially equal to the position acquired by the vehicle external antenna 5 for the position information distribution device 4. If it can be considered, or once the position of the terminal in the vehicle has been determined, the same effect can be obtained even if there is no terminal position and position information in the vehicle from the orientation recognition means 12.

  Alternatively, when the orientation of the seat and the usage form of the terminal are uniquely determined, or after the orientation of the terminal in the vehicle is once determined, the orientation of the terminal in the vehicle from the terminal position and orientation recognition means 12 is determined. Even if there is no information, the same effect can be obtained.

  Train seat information can be used as means for recognizing the position of the portable wireless terminal 2 inside the vehicle 1. In the case of a long vehicle 1 such as a train, it is assumed that there is a difference between the position information acquired by the vehicle external antenna 5 for the position information distribution device 4 and the position where the portable wireless terminal 2 is arranged. Information on reserved seats for trains can be obtained in advance by the mobile wireless terminal 2 using a seat reservation system using a mobile phone or a service using an IC card function of a mobile phone instead of a reserved seat ticket. is there. Alternatively, the user can input seat information to the portable wireless terminal 2 when sitting in the seat. Since the positional relationship between the position information acquired by the vehicle external antenna 5 and each seat changes according to the vehicle type, the in-vehicle position information is distributed by the first or second communication means. By doing so, the positional relationship between the fixed base station 3 and the portable wireless terminal 2 is correctly obtained, and the antenna directivity shift can be corrected with high accuracy. A user can set the traveling direction of the portable wireless terminal 2 in the vehicle 1 to the portable wireless terminal 2. In the case of a portable wireless device, since there are various usage forms, it may not be uniquely determined in which direction the portable wireless terminal 2 is facing in the vehicle 1. Therefore, the user can input the relationship between the direction of the terminal and the direction of the traveling direction of the vehicle 1 to the terminal to clearly define the direction of the antenna. In this way, the mobile radio terminal 2 can direct the antenna directivity toward the fixed base station 3, and the antenna directivity shift can be corrected with high accuracy.

  The mobile communication system of the present invention calculates a relative speed and a relative direction of a portable wireless terminal with a fixed base station using a simple wireless communication infrastructure in a vehicle, and becomes a Doppler frequency that becomes an obstacle to large-capacity communication with the fixed base station. Shifts and shifts in antenna directivity can be compensated. Therefore, it is useful as a mobile communication system that can stably maintain a large-capacity wireless data communication line with a base station even in a state where the vehicle is moving at a high speed.

Configuration diagram of mobile communication system in Embodiment 1 of the present invention Flowchart of mobile communication system in Embodiment 1 of the present invention Conceptual diagram of Doppler frequency shift calculation of mobile communication system in Embodiment 1 of the present invention Configuration diagram of mobile communication system according to Embodiment 2 of the present invention Flowchart of mobile communication system in Embodiment 2 of the present invention Conceptual diagram of relative direction calculation of mobile communication system in Embodiment 2 of the present invention Configuration diagram of a conventional mobile communication system Configuration diagram of a conventional mobile communication system Configuration diagram of a conventional mobile communication system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Portable radio | wireless terminal 3 Fixed base station 4 Position information distribution apparatus 5 External antenna 6 First antenna part 7 First radio circuit part 8 Second antenna part 9 Second radio circuit part 10 Doppler frequency calculation part 11 Frequency Correction Unit 12 Terminal Position and Orientation Recognition Unit 13 Relative Direction Calculation Unit 14 Antenna Directivity Correction Unit

Claims (6)

In a mobile communication system in which a portable wireless terminal used in a vehicle communicates with a fixed base station by a first wireless communication means,
Position information of the fixed base station is provided to the portable wireless terminal by the first wireless communication means, and from the position information distribution device installed in the vehicle to the portable wireless terminal by the second wireless communication means. Location information is provided,
A mobile communication system, wherein communication is performed by correcting a Doppler frequency of the first wireless communication means by calculating a relative speed between the fixed base station and the portable wireless terminal. In a mobile communication system in which a portable wireless terminal used in a vehicle communicates with a fixed base station by a first wireless communication means,
Position information of the fixed base station is provided to the portable wireless terminal by the first wireless communication means, and from the position information distribution device installed in the vehicle to the portable wireless terminal by the second wireless communication means. Position information is provided, and the relative direction between the fixed base station and the vehicle is calculated, and the relative direction between the fixed base station and the vehicle is calculated using the position and direction recognition means of the mobile terminal in the vehicle. A mobile communication system characterized by directing the antenna directivity of the portable radio terminal toward the fixed base station. The mobile communication system according to claim 2, wherein train seat information is used as means for recognizing a position of the portable wireless terminal in the vehicle. The mobile communication system according to claim 2, wherein a user inputs and sets the traveling direction of the vehicle to the portable wireless terminal as means for recognizing the direction of the portable wireless terminal in the vehicle. A portable radio terminal used in the mobile communication system according to claim 1,
In the portable wireless terminal configured to be communicable and used in the vehicle, the fixed base station by the first wireless communication means and the location information distribution device in which the vehicle is installed by the second wireless communication means,
Means for receiving position information of the fixed base station from the fixed base station by the first wireless communication means;
Means for receiving the position information of the vehicle by the second wireless communication means from the position information distribution device;
Means for calculating a relative speed between the fixed base station and the portable radio terminal;
Means for correcting and communicating the Doppler frequency of the first wireless communication means;
A portable wireless terminal comprising: A mobile radio terminal used in the mobile communication system according to any one of claims 2 to 4,
In the portable wireless terminal configured to be communicable and used in the vehicle, the fixed base station by the first wireless communication means and the location information distribution device in which the vehicle is installed by the second wireless communication means,
Means for receiving position information of the fixed base station from the fixed base station by the first wireless communication means;
Means for receiving the position information of the vehicle by the second wireless communication means from the position information distribution device;
Means for calculating a relative direction of the fixed base station and the vehicle;
Means for receiving or inputting terminal position and direction recognition information in the vehicle;
Means for controlling the antenna directivity in the direction of the fixed base station based on the direction calculated by the means for calculating the direction;
A portable wireless terminal comprising: