JP4675652B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a radio communication system, and more particularly to an improvement in the configuration of a base station side of a radio communication system.

Conventionally, a base station used in a wireless communication system includes an antenna for wireless communication, an amplification device for amplifying a wireless signal to be transmitted and received, and a control device for controlling communication in the base station, Many base stations were prepared and distributed in the entire system. And each base station carried one cell (refer patent document 1).
JP 2004-328638 A

  However, in the conventional system configuration described above, the configuration of the base station is complicated, and the apparatus has to be large, so that labor is required for its installation. In addition, when trying to change the cell configuration, a large-scale construction such as addition of base stations or improvement of the performance of existing base stations is required, and there is a problem that the cell configuration cannot be easily changed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wireless communication system capable of downsizing devices arranged in various places and easily changing a cell configuration.

  In order to solve the above-described problems, a wireless communication system according to the present invention includes an antenna, a plurality of wireless communication devices that transmit and receive communication signals using the antenna, and a mobile station device and the plurality of wireless communication devices. A wireless communication system that performs wireless communication with at least one of the wireless communication devices, comprising: a central control device that is communicatively connected to the plurality of wireless communication devices, the central control device comprising: A selection unit that selects at least one of the radio communication devices that are used for communication with the mobile station device among the radio communication devices and constitutes a relay device of the mobile station device, and at least one selected by the selection unit Communication means for communicating with the mobile station device using the relay device constituted by the wireless communication device, wherein each of the wireless communication devices is the antenna. And a relay means for amplifying the transmission signal transmitted from the communication means included in the centralized control apparatus and transmitting the signal through the antenna, while transmitting the received signal to the communication means included in the centralized control apparatus. It is characterized by.

  The system according to the present invention includes a centralized control device and a plurality of wireless communication devices, and the wireless communication device transmits a reception signal from an antenna provided in the wireless communication device to a communication unit included in the centralized control device. The transmission signal transmitted from the communication means is amplified and transmitted by the antenna. For this reason, the wireless communication apparatus does not need to have a configuration for various signal processing, and can be downsized. In addition, the central control device includes a selection unit that selects one of a plurality of wireless communication devices to be used for communication with the mobile station device. Therefore, by changing the selection method by the selection unit, the central control device side Thus, the cell configuration can be easily changed.

  The antenna may be a single antenna. The single antenna uses a basic antenna alone, and corresponds to, for example, a single dipole antenna. In this way, the wireless communication device can be sufficiently downsized.

  Further, the central control device further includes relay group storage means for storing a plurality of relay groups of the wireless communication device constituting the relay device having a part or all of the plurality of wireless communication devices as components. The selecting unit selects any one of the plurality of relay groups stored in the relay group storage unit, and the wireless communication device that is a component of the selected relay group is You may make it select as said relay apparatus of a mobile station apparatus. In this way, the cell configuration can be easily changed by changing the relay group stored in the relay group storage means.

  Further, the selection unit may select a part or all of the plurality of wireless communication devices based on a reception level of each signal transmitted from the mobile station device. In this way, for example, it is possible to configure a wireless communication device that communicates with the mobile station device by a wireless communication device that receives a signal transmitted from the mobile station device at a reception level higher than a threshold, and adaptively. The cell configuration can be changed.

  In this case, the selection unit may select, for each mobile station apparatus, one used for communication with the mobile station apparatus among the plurality of wireless communication apparatuses. In this way, an optimal cell can be set for each mobile station apparatus.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a wireless communication system according to an embodiment of the present invention. As shown in the figure, this wireless communication system 10 includes a plurality of small wireless communication devices 14 and a centralized control device 12, and provides communication services to a plurality of mobile station devices 16. It is supposed to be. The central control device 12 is mainly configured by a computer system, for example, and is connected to the base station data network 18 and the public network so as to be communicable. The small wireless communication device 14 is installed in place of the base station in the conventional wireless communication system, and is connected to the base station data network 18 and includes an antenna, and a plurality of mobile station devices are provided by the antenna. 16 is wirelessly multiplexed.

  As shown in FIG. 2, the small wireless communication device 14 includes an antenna 20, a power amplifier 22, a low noise amplifier 24, multipliers 28 and 30, a VCO (voltage controlled oscillator) 32, a DA converter 34, an AD converter 36, and a control unit. 38 and the network communication part 40 are comprised. Here, the antenna 20 transmits and receives radio signals to and from the mobile station device 16, and is a single antenna such as a single dipole antenna. The low noise amplifier 24 amplifies a weak radio signal received from the antenna 20 from the mobile station device 16. The amplified signal is converted into an intermediate frequency by the multiplier 28 and the VCO 32, and is converted into an AD converter. 36 is input. The AD converter 36 digitizes the received signal thus amplified and further converted to the intermediate frequency, and inputs it to the network communication unit 40 as broadband digital data. Then, the digital data is transmitted to the central control device 12 in real time via the base station data network 18 by the network communication unit 40 controlled by the control unit 38.

  In addition, the central control device 12 transmits digital transmission data to the small wireless communication device 14 via the base station data network 18. The network communication unit 40 controlled by the control unit 38 receives this digital data and inputs it to the DA converter 34. The DA converter 34 converts the input digital data into an analog signal and generates an analog transmission signal having an intermediate frequency. This signal is frequency-returned to a radio frequency by the multiplier 30 and the VCO 32 and input to the power amplifier 22. The power amplifier 22 amplifies the input signal and wirelessly transmits it using the antenna 20. The signal thus transmitted wirelessly is received by one or a plurality of mobile station devices 16. As described above, the small wireless communication device 14 does not have a configuration for modulation / demodulation unlike the conventional general base station, so that the small wireless communication device 14 can be downsized. It has been made easier.

  On the other hand, the centralized control device 12 includes network communication units 50 and 56, an antenna selection unit 52, and base station calculation units 54-1 to 54-n as shown in FIG. The network communication unit 50 receives broadband digital data via the base station data network 18 from the small wireless communication devices 14 arranged at a plurality of points. The antenna selection unit 52 selects one or more of the plurality of small wireless communication devices 14 that perform communication with the mobile station device 16 for each mobile station device 16. The base station computing unit 54-i (i = 1 to n) is assigned to each mobile station device 16 that is in communication, and is a small wireless communication device selected for each mobile station device 16 by the antenna selection unit 52. The broadband digital data transmitted from 14 is acquired, the phase and gain of these broadband digital data are adjusted, and the data transmitted from the mobile station device 16 is extracted. The data thus extracted is demodulated and decoded by a predetermined method, and the actual data is extracted therefrom. The actual data (for example, voice data, IP data, etc.) is transmitted to the public network via the network communication unit 56.

  Further, actual data (for example, voice data, IP data, etc.) received from the public network is received by the network communication unit 56, and this data is transmitted to the base station calculation unit 54 to which the mobile station device 16 that is the destination of the data is assigned. -I is input. The base station calculation unit 54-i encodes and modulates this data and supplies it to the antenna selection unit 52. The antenna selection unit 52 transmits the supplied data to the small wireless communication device 14 selected for communication with the mobile station device 16 that is the destination of the data.

  Here, a method of selecting the small wireless communication device 14 by the antenna selection unit 52 will be described. FIG. 4 is a diagram illustrating an arrangement state of the small wireless communication devices 14 of the wireless communication system 10. In the figure, each white circle indicates a small wireless communication device 14, and it can be seen that a large number of small wireless communication devices 14 are arranged in a plane. In this wireless communication system 10, small wireless communication devices 14 arranged in geographically close locations are grouped together to form a relay group. FIG. 5 shows a relay group table for managing this relay group. The relay group table shown in the figure stores a relay group ID for identifying each relay group and a small wireless communication device ID group for identifying each small wireless communication device belonging to the relay group in association with each other. This relay group table is stored in the antenna selection unit 52 of the central control apparatus 12, and can be appropriately edited (updated) by the administrator of this system.

  When any one of the small wireless communication devices 14 receives the location registration request from the mobile station device 16, the antenna selection unit 52 specifies the relay group ID of the relay group to which the small wireless communication device 14 belongs from the relay group table. Thereafter, communication with the mobile station device 16 is performed using the small wireless communication device 14 belonging to the relay group identified by the relay group ID.

  That is, a relay device of the mobile station device 16 is configured by the small wireless communication devices 14 belonging to the relay group, and the mobile station device 16 is connected to the centralized control device via the small wireless communication devices 14 constituting the relay device (relay group). Communication with 12 is performed.

  FIG. 6 is a communication sequence diagram showing a communication procedure by the wireless communication system 10. As shown in the figure, the small wireless communication devices 14 belonging to each relay group transmit broadcast information (S101, S102), and the mobile station device 16 that has received the broadcast information receives the broadcast received at the highest reception level. A location registration request is transmitted to the small wireless communication device 14 (or the relay group to which the small wireless communication device 14 belongs) that is the information transmission source (S103). The location registration request is transferred from the small wireless communication device 14 to the central control device 12, where the antenna selection unit 52 and the small wireless communication device 14 that is the destination of the location registration request are transmitted to the mobile station device 16. Is stored in association with the relay group ID of the relay group to which the group belongs, thereby completing the location registration. Although all the small wireless communication devices 14 transmit the notification information here, one or a plurality of small wireless communication devices 14 that transmit the notification information may be set for each relay group. Even in this case, the mobile station device 16 can be associated with the relay group most suitable for the communication.

  Thereafter, when a connection request is transmitted from the mobile station device 16, it is transmitted to the relay group that is the transmission destination of the location registration request (S104). The connection request is transferred to the central control apparatus 12 via the base station data network 18, and the central control apparatus 12 is a small wireless communication apparatus 14 belonging to a relay group associated with the mobile station apparatus 16 that is the transmission source of the connection request. The connection confirmation is returned using (S105). Thereafter, communication is performed between the mobile station device 16 and the centralized control device 12 using the small wireless communication devices 14 belonging to the relay group associated with the mobile station device 16 (S106).

  Further, when data is transmitted from the public network side to the mobile station apparatus 16 associated with any one of the relay groups, and the mobile station apparatus 16 requests connection from the central control apparatus 12 side, the mobile station A connection request is transmitted using the small wireless communication device 14 belonging to the relay group associated with the device 16 (S107). The mobile station device 16 that has received this connection request returns a connection confirmation (S108) and starts communication with the centralized control device 12 (S109). In the centralized control device 12, the data received by the antenna 20 of the small wireless communication device 14 associated with the mobile station device 16 and belonging to the relay group is used by the mobile station corresponding to the relay group in the base station calculation unit 54. The data transmitted from the device 16 is taken out and demodulated and decoded. When transmitting data to the mobile station device 16, the antenna 20 of the small wireless communication device 14 belonging to the relay group associated with the mobile station device 16 is used.

  The mobile station device 16 continues to receive the broadcast information transmitted from the small wireless communication devices 14 belonging to each relay group (S110, S111), and receives the broadcast information transmitted from the currently registered relay group. When the reception level of broadcast information transmitted from a relay group different from that of the relay group exceeds the level, a location registration request is transmitted to the relay group (S112), a connection request is transmitted (S113), and handover is performed. Request. On the other hand, when the connection confirmation is returned from the relay group that is the transmission destination of the connection request (S114), the mobile station device 16 starts communication with the relay group (S115).

  According to the wireless communication system 10 described above, the communication area by the wireless communication system 10 can be expanded by arranging the small wireless communication device 14 that is relatively easy to downsize, and the relay group table is updated. The combination of the small wireless communication devices 14 used for communication with each small wireless communication device 14, that is, the communication cell can be easily changed.

  The antenna selection unit 52 may select the small wireless communication device 14 used for communication with each mobile station device 16 by another method (reference). That is, in the radio communication system 10 according to the modification, the relay device used for communication with the mobile station device 16 according to the reception level of the signal transmitted from the mobile station device 16 in each small radio communication device 14a, 14b. The small wireless communication devices 14a and 14b constituting the (relay group) are selected. FIG. 7 is a diagram illustrating an arrangement state of the small wireless communication devices 14 in the wireless communication system 10 according to the modification. In the drawing, white circles usually indicate small wireless communication devices 14a, and black circles indicate small wireless communication devices 14b for notification. In the same figure, a state in which these are distributed in a plane is shown. . The configurations of the normal small wireless communication device 14a and the notification small wireless communication device 14b are the same as those of the small wireless communication device 14 shown in FIG. 2, whereas the notification small wireless communication device 14b constantly transmits notification information. In general, the small wireless communication device 14a is different in that the broadcast information is not transmitted.

  In the figure, mobile station device 16-1 indicates the position of mobile station device 16 at time T1, mobile station device 16-2 indicates the position of mobile station device 16 at time T2, and mobile station device. 16-3 has shown the position of the mobile station apparatus 16 in the time T3. That is, the mobile station device 16 is moving from the upper left to the lower right in the figure. A temporary base station cell 60-1 indicated by a broken line surrounds the small wireless communication devices 14a and 14b used for communication with the mobile station device 16 at time T1, and the temporary base station cell 60-2. Encloses the small wireless communication devices 14a and 14b used for communication with the mobile station device 16 at time T2, and the temporary base station cell 60-3 is used for communication with the mobile station device 16 at time T3. The small radio | wireless communication apparatuses 14a and 14b used are shown. As shown in the figure, when the mobile station device 16 moves, the reception level of each communication signal transmitted from the mobile station device 16 at each small wireless communication device 14 changes. Accordingly, the configuration of the small wireless communication devices 14a and 14b responsible for communication with the mobile station device 16, that is, the configuration of the temporary base station corresponding to the mobile station device 16 is changed. In this modification, for example, the small wireless communication device 14a used for communication with the mobile station device 16 by the small wireless communication devices 14a and 14b that receive communication signals transmitted from the mobile station device 16 at a reception level equal to or higher than a threshold value. , 14b, or a predetermined number of small wireless communication devices 14a, 14b from the small wireless communication devices 14a, 14b that receive communication signals from the mobile station device 16 at the highest reception level. By selecting the small wireless communication devices 14a and 14b used for communication, the optimum small wireless communication devices 14a and 14b constituting the relay device (relay group) used for communication with the mobile station device 16 are selected at any time. It has been reworked so that an optimal temporary base station is configured.

  FIG. 8 is a communication sequence diagram illustrating a communication procedure by the wireless communication system 10 according to the modification. As shown in the figure, each of the small notification wireless communication devices 14b for notification transmits notification information (S201, S202), and the mobile station device 16 that has received the notification information transmits the notification information received at the highest reception level. An approximate location registration request is transmitted to the notification small wireless communication device 14b which is the transmission source (S203). This approximate location registration request is transferred from the small informing wireless communication device 14b to the central control device 12, where the antenna selector 52 is the destination of the approximate location registration request with the mobile station device 16. The small wireless communication device 14b for notification is stored in association with it, thereby completing the approximate position registration.

  When the approximate position registration is completed, the mobile station device 16 is used by using the notification small wireless communication device 14b and / or the normal small wireless communication device 14a in the vicinity of the notification small wireless communication device 14b associated with the mobile station device 16. The reception level of the signal transmitted from is monitored. The centralized control device 12 selects each of the small wireless communication devices 14a and 14b in order to select the small wireless communication devices 14a and 14b in the vicinity of the notification small wireless communication device 14b in which the approximate location registration of the mobile station device 16 is performed. Is stored in advance. For example, the notification small wireless communication device 14b and / or the normal small wireless communication device 14a that has received the transmission signal from the mobile station device 16 at a reception level larger than the threshold is used for communication with the mobile station device 16. The small wireless communication device 14b for notification and / or the normal small wireless communication device 14a is selected. Then, a temporary base station is configured by the selected small wireless communication device 14b for notification and / or the normal small wireless communication device 14a, and any one of the base station calculation units 54 in the centralized control device 12 is connected to the temporary base station. assign.

  Thereafter, when a connection request is transmitted from the mobile station device 16 (S204), the notification small wireless communication device 14b and / or the normal small wireless communication device 14a selected for use in communication with the mobile station device 16 A connection request is extracted from the received data. Then, the centralized control device 12 sends back a connection confirmation using the notification small wireless communication device 14b and / or the normal small wireless communication device 14a constituting the temporary base station (S205). Thereafter, using the small radio communication device 14b for notification and / or the normal small radio communication device 14a constituting the temporary base station corresponding to the mobile station device 16, between the mobile station device 16 and the central control device 12 Communication is performed (S206). During the communication, the notification small wireless communication device 14b and / or the normal small wireless communication device 14a in the vicinity of the small notification wireless communication device 14b and / or the normal small wireless communication device 14a constituting the temporary base station are Search is performed using the position information, and the reception level of the signal transmitted from the mobile station device 16 is monitored by the small wireless communication devices 14a and 14b. Then, for example, the small notification wireless communication device 14b and / or the normal small wireless communication device 14a that has received a signal at a reception level larger than the threshold is used for communication with the mobile station device 16 for small notification wireless communication device 14b for notification. The configuration of the temporary base station is changed by selecting it as the normal small wireless communication device 14a.

  When data is transmitted from the public network side to the mobile station device 16, a connection request is sent from the central control device 12 side to the mobile station device 16. In this case, the mobile station apparatus 16 transmits a connection request to the mobile station apparatus 16 using the small notification wireless communication apparatus 14b for which the approximate location is registered (S207). The mobile station device 16 that has received this connection request returns a connection confirmation (S208) and starts communication with the centralized control device 12 (S209). In the centralized control device 12, the base station calculation unit 54 uses the data received by the antenna 20 of the notification small wireless communication device 14 b and / or the normal small wireless communication device 14 a constituting the temporary base station corresponding to the mobile station device 16. Of these, the data corresponding to the temporary base station is taken out, and the data transmitted from the mobile station device 16 is extracted, and demodulated and decoded. When transmitting data to the mobile station device 16, the small radio communication device 14b for notification and / or the antenna 20 of the normal small radio communication device 14a constituting the temporary base station corresponding to the mobile station device 16 is used.

  According to the radio communication system 10 according to the above modification, the configuration of the temporary base station corresponding to the mobile station device 16 is adapted according to the reception level of each signal transmitted from the mobile station device 16 in each small radio communication device 14. Therefore, communication between the mobile station device 16 and the centralized control device 12 can be realized in an optimum environment.

It is a figure which shows the whole structure of the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows the structure of a small radio | wireless communication apparatus. It is a figure which shows the structure of a centralized control apparatus. It is a figure explaining the selection method of the small radio | wireless communication apparatus of an antenna selection part. It is a figure which shows the content of the relay group table. It is a communication sequence diagram which shows the communication procedure of the radio | wireless communications system which concerns on embodiment of this invention. It is a figure explaining the selection method of the small radio | wireless communication apparatus of the antenna selection part in the radio | wireless communications system which concerns on a modification. It is a communication sequence diagram which shows the communication procedure of the radio | wireless communications system which concerns on a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Radio | wireless communications system, 12 Centralized control apparatus, 14 Small radio communication apparatus, 14a Normal small radio communication apparatus, 14b Small radio communication apparatus for information, 16 Mobile station apparatus, 18 Base station data network, 20 Antenna, 22 Power amplifier, 24 Low noise amplifier, 28, 30 multiplier, 32 VCO (voltage controlled oscillator), 34 DA converter, 36 AD converter, 38 control unit, 40, 50, 56 network communication unit, 52 antenna selection unit, 54-1 to 54 -N Base station calculation unit, 60-1 to 60-3 Temporary base station.

Claims (3)

A wireless communication system comprising a plurality of wireless communication devices that perform wireless communication with a mobile station device via an antenna, and a centralized control device that is connected to communicate with the plurality of wireless communication devices,
The central control device is:
The configuration of the relay group corresponding to said each mobile station apparatus as a component part or all of the plurality of wireless communication devices, greater than the reception level threshold value of a radio signal transmitted from each pre-Symbol mobile station apparatus Means for changing to comprise a wireless communication device ;
Means for communicating with the mobile station device corresponding to the relay group using a wireless communication device included in the relay group,
The wireless communication device
Means for transmitting a signal received by the antenna to the centralized control device and transmitting a signal transmitted from the centralized control device by the antenna;
A wireless communication system. The wireless communication system according to claim 1, wherein
The antenna is a single antenna;
A wireless communication system. A centralized control device that communicates and connects with a plurality of wireless communication devices that perform wireless communication with a mobile station device via an antenna,
The configuration of the relay group corresponding to said each mobile station apparatus as a component part or all of the plurality of wireless communication devices, greater than the reception level threshold value of a radio signal transmitted from each pre-Symbol mobile station apparatus Means for changing to comprise a wireless communication device ;
Using a wireless communication device included in the relay group, and communicating with the mobile station device corresponding to the relay group,
Centralized control device characterized by that.

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