JP2560786B2 - Mobile communication system, mobile terminal and vehicle-mounted repeater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mobile communication system, a mobile terminal, and a vehicle-mounted repeater, and particularly in a city area, a micro zone covers a service area, and in a suburb, a small zone covers a service area. The present invention relates to a mobile communication system composed of a base station and a mobile terminal device, a mobile terminal, and a vehicle-mounted repeater.

[Conventional technology]

BACKGROUND ART Conventional mobile communication systems have been variously improved with the first problem being how to handle a large amount of calls in a limited frequency band. As a result, a small zone system car telephone system, which is currently known as a cell system, has been put into practical use. However, the car telephone system of this small zone system also showed remarkable growth after the start of the service, and a shortage of communication channels is being screamed all over the world. This tendency is particularly remarkable in urban areas where traffic is concentrated. For example, looking at the distribution of mobile phone traffic in Tokyo, intense traffic concentration is observed around Chiyoda Ward and Aoyama. Therefore, it takes three to four times (20 to 30 seconds) as usual from the time of calling to the time of calling. This is because there is a shortage of call channels, and in order to cope with this, telecommunications carriers subdivide zones in Tokyo to increase subscriber capacity. This is the reason why Nikkei Electronics No. 401, pages 91 to 1
See page 04 for details.

In addition, as a new movement of the car telephone system, the introduction of a portable terminal that can be carried by a subscriber has been realized. Since such a portable terminal is strongly required to be small and lightweight, it is not possible to increase the transmission power of the wireless device so much. Therefore, subdivision of the zone is also required from this aspect. Therefore, in future mobile communication systems, microzone systems with extremely small zone radius are required at least in urban areas.

However, this microzone system increases the system cost because the number of base stations increases significantly. The system cost may be a little higher in urban areas with a large number of subscribers, but in the suburbs where the number of subscribers is not so large, such a microzone system is not economically attractive, so the small zone system used today is Will continue the service.

[Problems to be Solved by the Invention]

In the above-mentioned conventional mobile communication system, the serviceability is a big problem when a mobile terminal is introduced. Mobile terminals with low transmission power can receive services within the microzone, but have a problem that they can receive services only in a very limited area in the suburban small zone area, that is, near the base station.

It is an object of the present invention to provide a mobile communication system and a mobile terminal device that can maintain high serviceability even for a mobile terminal with low transmission power and can eliminate the congestion of frequencies in the center of the city. .

[Means for solving the problem]

A mobile communication system of the present invention is a mobile communication system composed of a base station and a mobile terminal device that cover a service area in a micro zone in a city area and a service area in a small zone in a suburb. A plurality of base stations which broadcast by adding to the control signal whether it is a small zone base station or a small zone base station, and when the control signal from the base station is received and the micro zone is received, the base station directly communicates with the base station. A mobile terminal having a transmission power, an in-vehicle repeater that relays and amplifies a transmission signal of the mobile terminal to a high transmission power when the mobile terminal is in the small zone, and the mobile communication at the small zone base station. To ensure that the mobile terminal can be used for communication with the in-vehicle repeater from among a plurality of frequencies assigned to the system, secure it without using it for normal communication. And a specific frequency.

Further, the mobile terminal of the present invention is provided on a mobile terminal device side of a mobile communication system composed of a base station and a mobile terminal device which cover a service area in a micro zone in a city area and a service area in a small zone in a suburb. A mobile terminal which is provided and is connectable to an onboard repeater used when in the small zone, receives a control signal transmitted from the base station, and determines whether the mobile terminal is in the microzone or in the small zone. The determination circuit, a control circuit that sends a relay request signal to the vehicle-mounted relay only when the output of the determination circuit indicates that the vehicle-mounted relay is in a small zone, and the vehicle-mounted relay when the vehicle is in the microzone. It is characterized by having a radio that communicates via the vehicle-mounted repeater when in a small zone without intervention.

Further, the mobile terminal of the present invention is a vehicle-mounted repeater used in a mobile communication system composed of a base station and a mobile terminal device that cover a service area in a microzone in a city area and a service area in a small zone in a suburb. In the portable terminal detachable therefrom, a determination circuit for receiving a control signal transmitted from the base station and determining whether the control signal is in the micro zone or in the small zone, and the determination circuit output is in the small zone. The control circuit that sends a relay request signal to the vehicle-mounted repeater only when it indicates that the vehicle-mounted relay is present, and the vehicle-mounted relay when the vehicle is in the microzone and not in the vehicle-mounted relay when the vehicle is in the microzone. A wireless device that communicates via the vehicle, an attachment / detachment detection circuit that detects attachment / detachment to / from the in-vehicle relay device, and the wireless device when the portable terminal is attached to the in-vehicle relay device. It is characterized by comprising a plurality of switch units for switching the input / output connection of the machine from the built-in antenna to the input / output terminal connected to the vehicle-mounted repeater and controlling the determination circuit not to operate.

Further, the vehicle-mounted repeater of the present invention is detachable for use in a mobile communication system composed of a base station and a mobile terminal device that cover a service area in a microzone in a city area and a service area in a small zone in a suburb. In a vehicle-mounted repeater connected to a mobile terminal, a receiver that receives a signal from the mobile terminal, a startup circuit that determines a relay request signal from the signal received by the receiver, and outputs a startup signal, the mobile terminal A frequency converter for converting the signal from the frequency converter, an amplifier that is activated by the activation circuit output and amplifies the output of the frequency converter, an attachment / detachment detection circuit that detects attachment / detachment of the mobile terminal, and the mobile terminal when the mobile terminal is worn. An input terminal for receiving the output of the terminal, an output terminal for sending an incoming signal to the mobile terminal when the mobile terminal is worn, and a mobile terminal controlled by the attachment / detachment detection circuit. A first switch that uses the signal from the input terminal as the input of the amplifier when the terminal device is mounted and the output of the frequency converter as the input of the amplifier when the mobile terminal is separated, and a power detector that detects the power of the signal from the input terminal. A second switch that is controlled by the attachment / detachment detection circuit, selects the output of the power detection circuit when the portable terminal is worn, and selects the output of the start circuit when the portable terminal is detached and outputs the power-on signal of the amplifier. It is characterized by having.

[Action]

In order to provide mobile terminals with low transmission power in all regions, there is no solution except to make all regions into microzones. As a practical solution, the present invention provides a mobile communication system and a mobile terminal that are equipped with a repeater in a car in the suburbs and can provide a service if the action range of a subscriber is within a certain distance from the car.

If this method is adopted in all regions, radio is used from the mobile terminal to the car, and from the car to the base station. Therefore, in the present invention, a mobile terminal communicates directly with a microzone base station in an urban area with high traffic, and in a suburb with little traffic and plenty of frequency, a repeater is installed in an automobile to communicate with a small zone base station. To do. In order to enable the same mobile terminal to communicate directly with the base station and also to use the repeater installed in the car, it is necessary to determine whether the mobile terminal is in the micro zone or the small zone, and When it is in the zone, it directly communicates with the base station, and when it is in the small zone, it communicates with the base station through a repeater installed in the vehicle.

Further, as described above, the communication of the base station of the automobile in the small zone needs to be set to a frequency that does not interfere with the communication between the base station and the automobile. As mentioned in the section of the prior art, since traffic is concentrated in urban areas, there are frequencies that do not need to be used in suburban small zone areas. This can be uniformly set for the entire system and assigned as a frequency for communication between the mobile terminal and the repeater of the vehicle.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

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

The mobile terminal 10 exists in the area of the microzone base station 1, and the mobile terminal 11 and the vehicle-mounted relay 20 exist in the area of the small zone base station 2.

FIG. 2 is a frequency channel layout diagram of an embodiment of the present invention.

Mobile terminal 10 in the area of Microzone base station 1
Knows that it is in the microzone based on the control signal from the microzone base station 1, and directly communicates with the microzone base station 1. On the other hand, the mobile terminal 11 in the area of the small zone base station 2 knows that it is in the small zone by the control signal from the small zone base station 2,
Since the transmission power is low, it is impossible to directly communicate with the small zone base station 2. Therefore, the mobile terminal 11 sends a relay request signal to the in-vehicle repeater 20, and the in-vehicle repeater 20 receives the mobile terminal.
The signal from 11 is relayed and amplified to communicate with the small zone base station 2. In this case, the mobile terminal 11 and the vehicle-mounted repeater
As the frequency used for communication with 20, the frequency assigned in advance to this system is used as shown in B and D of FIG. 2A and C are used for communication between the small zone base station 2 and the vehicle-mounted repeater 20 in the area of the small zone base station 2, and in the area of the microzone base station 1, the microzone base stations are shown. 1 and mobile terminal
Used for communication with 10. By performing such control, even a small mobile terminal with low transmission power
It is possible to receive a service within a certain distance directly from a vehicle-mounted repeater installed in an automobile in the suburbs in a micro zone in an urban area, and it is possible to provide a system with high serviceability.

FIG. 3 is a block diagram of a mobile terminal according to an embodiment of the present invention.

FIG. 3 (a) is a block diagram of the first embodiment of the portable terminal of the present invention. This portable terminal is used without being connected to the vehicle-mounted repeater by being attached or detached.

The signal received from the antenna 100 is input to the receiver 112 via the hybrid circuit 111. At the same time, the received signal is input to the determination circuit 120. The determination circuit 120 receives the control signal from the base station and determines whether the mobile terminal is in the small zone or the micro zone. When it is determined that the determination circuit 120 is in the microzone, the output of the receiver 112 is output from the terminal 101 without outputting a control signal, and the transmission signal input from the terminal 102 is transmitted by the transmitter 113. It operates as a normal radio that modulates and transmits. Therefore, it can be said that the antenna 100, the hybrid circuit 111, the receiver 112, and the transmitter 113 form the wireless device 110. When the determination circuit 120 determines that the vehicle is in the small zone, the control circuit 130 generates a relay request signal for the on-vehicle relay by the output of the determination circuit 120, and the transmitter 113
To send via. At the same time, the frequencies used by the receiver 112 and the transmitter 113 are set to B and D, respectively. By doing this, if there is a mobile terminal in the small zone,
It is possible to communicate with the base station via the vehicle-mounted repeater.

FIG. 3 (b) is a block diagram of the second embodiment of the portable terminal of the present invention. This mobile terminal is attachable to and detachable from the vehicle-mounted repeater.

As the reference numerals in FIG. 3 (b), the same constituents as those shown in FIG. 3 (a) are designated by the same reference numerals and can be realized with the same circuit configuration.

The mobile terminal of the second embodiment also operates in the same manner as the mobile terminal of the first embodiment when it is used separately from the vehicle-mounted repeater. However, when the portable terminal is mounted on the vehicle-mounted repeater, the attachment / detachment detection circuit 140 detects it and switches the switches 151, 152, and 153, respectively. As a result, the determination circuit 120 does not operate, and the received signal is input terminal 103
And the transmission signal is output from the output terminal 104. Each terminal is respectively connected to the reception signal terminal and the transmission signal terminal of the vehicle-mounted repeater. By doing so, the mobile terminal performs the same operation as the on-vehicle terminal when the mobile terminal is mounted on the on-vehicle relay, and does not particularly change the operation depending on whether the mobile terminal is in the micro zone or the small zone. In this way, by configuring the mobile terminal to be attachable to and detachable from the vehicle-mounted repeater, it is not necessary to wirelessly transmit between the mobile terminal and the vehicle-mounted repeater when used in an automobile, so that reliability is also improved. It is also possible to reduce the battery consumption of the mobile terminal.

FIG. 4 is a block diagram of a vehicle-mounted repeater according to an embodiment of the present invention.

FIG. 4 (a) is a block diagram of a first embodiment of an in-vehicle repeater corresponding to the first embodiment of the mobile terminal of the present invention.
The portable terminal of the first embodiment is used without being connected to the vehicle-mounted repeater by being attached or detached.

The signal received from the antenna 200 is input to the receiver 220 via the hybrid circuit 211. The signal demodulated by the receiver 220 is input to the activation circuit 230 that detects the relay request signal from the mobile terminal. When the starting circuit 230 detects the relay request signal, the starting circuit 230 then outputs a signal for turning on the power of the amplifier 250. By doing so, the signal from the mobile terminal input from the antenna 200 is converted to a frequency (the part B in FIG. 2 is the part A) in the frequency conversion circuit 240 and output. It Similarly, the received signal from the base station is also converted into a frequency at which communication with the mobile terminal is possible (C in FIG. 2 is the frequency of D) and is output.

FIG. 4 (b) is a block diagram of a second embodiment of an in-vehicle relay device corresponding to the second embodiment of the mobile terminal of the present invention.
The mobile terminal connected to the vehicle-mounted repeater of the second embodiment is
It can be detached and used.

As reference numerals in FIG. 4 (b), the same elements as those shown in FIG. 4 (a) have the same numerals and can be realized with the same circuit configuration.

When the mobile terminal is not attached to the vehicle-mounted repeater, the same operation as in FIG. 4 (a) is performed. Next, when the portable terminal is attached to the vehicle-mounted repeater, the attachment / detachment detection circuit 260 detects the attachment and switches the switches 281, 282 respectively. As a result, the reception signal is output from the terminal 201 and the transmission signal is input from the terminal 202. Also, power on the amplifier 250 as a terminal
This is done by detecting the power of the input signal from 202 with the power detection circuit 270. By performing such control, when the mobile terminal is worn, it can be operated as an in-vehicle terminal.

It should be noted that in the present embodiment, only turning on the power is described, and cutting off the power is not particularly mentioned. The reason for this is that any method may be used for disconnecting the power supply, and the general idea is to send a disconnection signal from the mobile terminal to disconnect it when the mobile terminal is operating separately. To realize the circuit. Further, when the mobile terminal is mounted on the vehicle-mounted repeater, the user may turn off the power supply.

Further, the frequency conversion circuit is usually realized only by multiplying a specific frequency, but when the modulation signal is a digital signal, if the demodulated digital signal is once again modulated with a different frequency. It is well known that error can be reduced. However, in this case, the circuit becomes a little complicated.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention provides a mobile communication system and a mobile terminal device that can maintain high serviceability even for a mobile terminal with low transmission power and can eliminate frequency congestion in the central area of Tokyo. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a frequency channel arrangement diagram of an embodiment of the present invention, and FIG. 3 (a) is a block of a first embodiment of a mobile terminal of the present invention. FIG. 3 (b) is a block diagram of a second embodiment of the mobile terminal of the present invention, and FIG. 4 (a) is a block diagram of a vehicle-mounted repeater corresponding to the first embodiment of the mobile terminal of the present invention. 4 is a block diagram of the first embodiment, FIG.
FIG. 8B is a block diagram of a second embodiment of an in-vehicle repeater corresponding to the second embodiment of the mobile terminal of the present invention. 1 ... Microzone base station, 2 ... Small zone base station,
10, 11 ...... Mobile terminal, 20 ...... In-vehicle repeater, 103 …… Input terminal, 104 …… Output terminal, 110 …… Radio, 111, 211 …… Hybrid circuit, 112, 220 …… Receiver, 113 …… Transmitter ,
120 …… Judgment circuit, 130 …… Control circuit, 140,260 …… Detachment detection circuit, 230 …… Starting circuit, 240 …… Frequency conversion circuit,
250 …… Amplifier, 270 …… Power detection circuit.

Front page continued (72) Inventor Fumiyasu Hayakawa 5-33-1 Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Tomoki Osawa 5-33-1 Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Kazuhiro Okanoue 5-33-1 Shiba, Minato-ku, Tokyo, NEC Corporation (56) Reference JP-A-62-126726 (JP, A)

Claims (4)

(57) [Claims] 1. In a mobile communication system comprising a base station and a mobile terminal device which cover a service area in a micro zone in an urban area and cover a service area in a small zone in a suburb, are each a micro zone base station? A plurality of base stations that broadcast by adding to the control signal whether it is a small zone base station,
A mobile terminal of low transmission power that receives a control signal from the base station and directly communicates with the base station when in the micro zone, and a transmission signal of the mobile terminal when the mobile terminal is in the small zone. In-vehicle repeater that relays and amplifies to high transmission power, and in the small zone base station, the mobile terminal is used for communication with the in-vehicle repeater from a plurality of frequencies assigned to the mobile communication system. A mobile communication system including a specific frequency which is reserved for normal communication without being used for normal communication. 2. A mobile terminal device side of a mobile communication system comprising a base station and a mobile terminal device which covers a service area in a micro zone in a city area and covers a service area in a small zone in a suburb. In a portable terminal connectable to an in-vehicle repeater used when in a zone, a determination circuit that receives a control signal transmitted from the base station and determines whether it is in a micro zone or a small zone, A control circuit that sends a relay request signal to the vehicle-mounted repeater only when the determination circuit output indicates that the vehicle is in the small zone, and a small-sized control circuit that does not go through the vehicle-mounted repeater when in the microzone. A mobile terminal having a wireless device that communicates via the vehicle-mounted repeater when in a zone. 3. An in-vehicle repeater used in a mobile communication system comprising a base station and a mobile terminal device, which cover a service area in a micro zone in a city area and cover a service area in a small zone in a suburb, and attach / detachment therefrom. In a portable terminal capable of performing the following, a judgment circuit for judging whether the control signal sent from the base station is received to determine whether it is in the microzone or in the small zone, and the judgment circuit output indicates that the output is in the small zone. Communication via the on-vehicle repeater when the vehicle is in the micro zone and the control circuit that sends a relay request signal to the on-vehicle relay when the vehicle is in the micro zone. A wireless device to be performed, an attachment / detachment detection circuit for detecting attachment / detachment to / from the vehicle-mounted repeater, and an input / output connection of the wireless device when the portable terminal is attached to the vehicle-mounted repeater. A mobile terminal comprising: a plurality of switch units for switching the connection from an internal antenna to an input / output terminal connected to the vehicle-mounted repeater and controlling the determination circuit not to operate. 4. Connected to a detachable mobile terminal used in a mobile communication system composed of a base station and a mobile terminal device which covers a service area in a micro zone in an urban area and a service area in a small zone in a suburb. In a vehicle-mounted repeater, a receiver that receives a signal from the mobile terminal, a start circuit that determines a relay request signal from the signal received by the receiver and outputs a start signal, and a signal from the mobile terminal with a frequency A frequency converter for converting, an amplifier which is started by the output of the starting circuit and amplifies the output of the frequency converter, an attachment / detachment detection circuit for detecting attachment / detachment of the mobile terminal, and an output of the mobile terminal when the mobile terminal is worn Input terminal, an output terminal for transmitting an incoming signal to the mobile terminal when the mobile terminal is worn, and an input terminal which is controlled by the attachment / detachment detection circuit when the mobile terminal is worn. A first switch having a signal from an input terminal as an input of the amplifier and an output of the frequency converter as an input of the amplifier when the mobile terminal is separated; a power detection circuit for detecting power of a signal from the input terminal; A second switch which is controlled by the attachment / detachment detection circuit, selects the output of the power detection circuit when the mobile terminal is worn, and selects the output of the startup circuit when the mobile terminal is detached and outputs the power-on signal of the amplifier. In-vehicle repeater.