JP2010093385A - Repeater device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repeater device for changing the antenna pattern of radiowave to be transmitted in response to the position of a radio terminal. <P>SOLUTION: The repeater device RS for repeating a radio connection between a radio base station device CS connected to a radio communication network NW and the radio terminal PS includes: a plurality of antennas for transmitting/receiving the radiowave to be used for communication with the radio base station device CS or the radio terminal PS; a position determining means for determining whether or not the radio terminal is positioned within a range for communication without cables, based on radiowave which is transmitted from the radio terminal PS to be connected to its own repeater device RS and is received by the antenna; and an antenna pattern control means for changing the antenna pattern being the distribution of the radiowave to be transmitted from the antenna, so as to transmit the radiowave toward the radio terminal PS, when the position determining means determines that the radio terminal is positioned within the range for communication without cables. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a repeater apparatus that retransmits a radio wave transmitted from a radio base station apparatus in a radio communication system to a place where radio waves are difficult to reach such as indoors.

  In recent years, with the expansion of the service area of wireless terminal devices such as mobile phones and PHS (Personal Handy-phone System), wireless terminal devices are not only used on the go, but also have the opportunity to be used indoors such as at home or in stores. It has increased. When a wireless terminal device is used indoors, radio waves used for communication between the wireless base station device and the wireless terminal device, except in the vicinity of windows, are attenuated by the walls and beams of the building, and a sufficient communication environment is obtained. It may not be possible. Such a phenomenon becomes more prominent as the frequency of radio waves used in the wireless communication system increases, and the indoor communication environment deteriorates.

  In order to solve such a problem, a repeater device that relays a radio wave connecting a wireless base station device and a wireless terminal device is introduced into a home or a store by a business operator such as a mobile phone. Many current repeater devices simply amplify radio waves and transmit them in all directions, and the distribution of radio waves transmitted from the repeater devices, that is, the antenna pattern that is the shape of the cover area of the repeater device is almost circular. The cover area is fixed. In the fixed cover area, the same frequency cannot be used in the same radio slot, that is, at the same timing in order to prevent radio wave interference. When other repeater devices are installed in the vicinity, if the cover areas overlap each other, it will be impossible to communicate using the same frequency at the same timing using these repeater devices. There is a case.

Further, for example, Patent Document 1 discloses a technique for forming an antenna pattern in accordance with an area to be installed and covered with a repeater device. However, this technology describes that when installing a repeater device, it is necessary to select an antenna pattern that is in the shape of a wireless zone according to the installation location, and to further adjust the antenna pattern by the installer. Therefore, in such a technique, it takes time and labor to adjust the antenna pattern for each installation location, and there is a problem that the antenna pattern cannot be changed in accordance with the position of the wireless terminal device.
Japanese Patent Laid-Open No. 10-126325

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a repeater device that changes an antenna pattern of a radio wave to be transmitted according to the position of a wireless terminal device.

  In order to achieve the above object, a repeater apparatus according to the present invention is a repeater apparatus that relays a radio connection between a radio base station apparatus and a radio terminal apparatus connected to a radio communication network, the radio base station apparatus or the radio base station apparatus A plurality of antennas for transmitting or receiving radio waves used for communication with a wireless terminal device, and a range in which wireless communication is possible based on the radio waves transmitted from the wireless terminal device connected to its own repeater device and received by the antenna A position determining means for determining whether or not the mobile terminal is located; and when the position determining means determines that the mobile terminal is located within a wirelessly communicable range, radio waves are transmitted to the wireless terminal device. And antenna pattern control means for changing an antenna pattern which is a distribution of radio waves transmitted from the antenna.

  According to the repeater device of the present invention, it is possible to change the antenna pattern of the radio wave to be transmitted according to the position of the wireless terminal device.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram of a wireless communication system showing an embodiment of a repeater device of the present invention.
This radio communication system includes a radio communication network NW, radio base station apparatuses CS1 and CS2, a repeater apparatus RS, and radio terminal apparatuses PS1, PS2, and PS3. The radio base station apparatus CS (common to CS1 and CS2) is connected to the radio communication network NW and is an area where radio waves transmitted from its own radio base station apparatus CS, called a radio zone, reach radio terminal apparatuses PS (PS1 to PS3). Common)) wirelessly. Although FIG. 1 shows only two radio base station apparatuses CS and only three radio terminal apparatuses PS, a large number of radio base station apparatuses CS are connected to the mobile communication network NW, and a large number of radio terminal apparatuses PS are connected. It can communicate with the radio base station apparatus CS by radio.

  The repeater apparatus RS is installed near a window that can communicate with the radio base station apparatus CS indoors, for example, at home or in a store, and receives radio waves received from the radio base station apparatus CS from radio base station apparatuses CS. Is transmitted toward the wireless terminal device PS located indoors where it is difficult to reach. This repeater apparatus RS enables the radio terminal apparatus PS to communicate wirelessly even indoors where radio waves from the radio base station apparatus CS are difficult to reach.

FIG. 2 is a block diagram showing a configuration of a repeater device RS showing an embodiment of the present invention.
The repeater device RS includes a control unit 11, a demodulation unit 12, a modulation unit 13, an amplification unit 14, a power amplification unit 15, and a duplexer 16.

  The modulation unit 13 modulates a signal to be transmitted from a baseband signal to an RF signal and outputs the modulated signal to the power amplification unit 15. The power amplifying unit 15 amplifies the power of the signal to be transmitted. The power amplifying unit 15 amplifies the RF signal input from the modulation unit 13 with an amplification factor indicated by the control unit 11 and outputs the amplified signal to the duplexer 16. The duplexer 16 is for switching the connection of the antenna that transmits and receives signals wirelessly to the power amplifying unit 15 or the amplifying unit 14 depending on whether the signal is transmitted or received. When transmitting a signal, the RF signal input from the power amplifier 15 is transmitted from a plurality of antennas.

  When the RF signal is received from the antenna, the duplexer 16 outputs the received RF signal to the amplifier 14. The amplifier 14 amplifies the signal component of the RF signal received from the antenna and outputs it to the demodulator 12. When receiving an RF signal from the amplifier 14, the demodulator 12 demodulates the RF signal into a baseband signal. The control unit 11 controls the entire repeater device RS, and is connected to the demodulation unit 12, the modulation unit 13, the amplification unit 14, the power amplification unit 15, and the duplexer 16, from the wireless terminal device PS to the repeater device. When a signal indicating a request for connection to the RS is received, the signal is output from the duplexer 16 to the control unit 11 via the amplification unit 14. Then, the control unit 11 determines the position of the wireless terminal device PS from the signal indicating the connection request output from the amplification unit 14.

  Furthermore, the duplexer 16 is provided with a phase shifter that shifts the phase, which is one parameter for changing the directivity of radio waves transmitted from a plurality of antennas. The phase shift between the plurality of antennas can be changed by instructing the phase shift amount of the phase of the radio wave transmitted from the antenna. In order to change the directivity of radio waves transmitted from a plurality of antennas, in addition to changing the phase, it is necessary to change the power of radio waves transmitted from each antenna. By changing the phase and power of radio waves transmitted from a plurality of antennas, the directivity of radio waves transmitted from the plurality of antennas is changed.

  The directivity of the radio wave indicates an antenna pattern that is a radio wave distribution. The duplexer 16 includes a phase shifter. The phase shift amount of the phase shifter and the amplification factor of the amplifier 15 are determined based on the position of the radio terminal apparatus PS. The antenna pattern can be changed by the control unit (antenna pattern control means) 11 according to the control.

Here, the process of changing the antenna pattern will be described.
First, when the duplexer 16 receives a signal indicating a connection request from the wireless terminal device PS via the antenna, the signal is output to the control unit 11 via the amplification unit 14. The control unit 11 to which the connection request is input instructs the power amplification unit 15 to amplify the power in order to transmit the radio wave in the direction of the wireless terminal device PS, and shifts the phase of the radio wave to the duplexer 16. Instruct.

  Next, referring to FIG. 3, when the repeater apparatus RS receives a connection request from the wireless terminal apparatus PS, it establishes a connection with the wireless terminal apparatus PS, and the repeater apparatus RS transmits radio waves transmitted to the wireless terminal apparatus PS. A process of following the movement of the wireless terminal device PS by changing the antenna pattern will be described.

FIG. 3 is a sequence diagram illustrating an example of processing of the repeater apparatus RS.
First, a connection request transmitted from the wireless terminal device PS is received (S101). When the connection request is received, the carrier that is a process of confirming the combination of the frequency and the radio slot used by the radio base station device CS or other repeater device RS around the repeater device RS under the initiative of the control unit 11 Sense is performed and a free channel for establishing a connection of the wireless terminal device PS is confirmed (S102). When an empty channel is confirmed, a channel is allocated to the wireless terminal device PS (S103). This channel assignment is performed by processing such as transmitting a connection response from the repeater device RS to the wireless terminal device PS. When the channel is assigned, the wireless terminal device PS establishes a wireless connection and starts communication.

  Here, when the wireless terminal device PS is connected, the radio wave transmitted from the wireless terminal device is monitored in order to monitor whether or not the wireless terminal device PS is located in a range where it can communicate with its own repeater device RS. Then, it is determined whether or not the level is higher than the receivable level of the repeater device RS (position determination means) (S104). This receivable level uses a known index representing the quality of radio waves, such as radio wave intensity and SNR (Signal to Noise Ratio). If it is less than the receivable level of the repeater device RS, the wireless connection cannot be maintained, and the process is terminated.

  If the level is higher than the receivable level, it is determined whether or not there is a wireless terminal device PS that may interfere with the wireless terminal device PS that has transmitted the connection request around its own repeater device RS. Interference avoidance determination means) (S105). Here, the case where there is a possibility of the interference is a case where there is a wireless terminal device using a channel of the same frequency or a nearby wireless slot around the wireless terminal device PS that has transmitted the connection request. When there is a radio terminal apparatus PS that has such a possibility of interference, the frequency is close to the position of the radio terminal apparatus PS so that radio waves of that frequency are not transmitted in the direction of the radio terminal apparatus PS that has the possibility of interference. A place called a null point or an insensitive point where the amplitude of the radio wave cancels out and becomes zero or weak (generating a null point is called null steering) and communicating with its own repeater RS An antenna pattern is formed so that radio waves reach the wireless terminal device PS (S106). This antenna pattern is formed by controlling the degree of power amplification by the power amplifying unit 15 and the degree of phase change of the phase shifter provided in the duplexer 16. When an appropriate antenna pattern is formed in this way, it is monitored again whether the wireless terminal device PS is in a range where communication with the repeater device RS is possible (S104).

  In step S105, if there is no risk of interference with the wireless terminal device PS that may interfere with the wireless terminal device PS that has transmitted the connection request, whether the position of the wireless terminal device PS is in the current antenna pattern or not. If it is in the antenna pattern, it is determined that it is not necessary to change the antenna pattern. If it is not in the antenna pattern, it is determined that it is necessary to change the antenna pattern so that radio waves reach the wireless terminal device PS (S107). If it is determined that it is not necessary to change the antenna pattern, it is monitored again whether the wireless terminal device PS is in a range where communication with the repeater device RS is possible (S104). If it is determined that it is necessary to change the antenna pattern, the antenna pattern is changed so that the radio wave reaches the wireless terminal device PS (antenna pattern control means) (S108). After the antenna pattern is changed, it is monitored again whether the wireless terminal device PS is in a range where communication with the repeater device RS is possible, and thereafter the same processing is repeated.

  FIG. 4 is a diagram illustrating an example of an antenna pattern when the repeater apparatus RS communicates with the wireless terminal apparatus PS3 wirelessly. First, FIG. 4A is a diagram illustrating an example of an antenna pattern when the repeater apparatus RS does not automatically control the antenna pattern. Since the antenna pattern is fixed in time, the connection is cut when the wireless terminal device PS3 moves outside the antenna pattern. There is also a risk of interference with the wireless terminal device PS2 that does not communicate with the repeater device RS.

  On the other hand, FIG.4 (b) is a figure which showed an example of the antenna pattern in case the repeater apparatus RS controls an antenna pattern automatically by the process shown in FIG. Even if the wireless terminal device PS3 that communicates with the repeater device RS moves, interference with the wireless terminal device PS2 can be prevented while continuing communication with the wireless terminal device PS3 as long as communication with the repeater device RS is possible. .

  As described above, the repeater device RS changes the antenna pattern by controlling the phase shifter and the power amplifying unit 15 according to the received radio wave, so that even if the wireless terminal device PS moves, the repeater device RS does not move. The antenna pattern can be automatically followed. In addition, when a wireless connection is established with the wireless terminal device PS, the antenna pattern can be changed in accordance with the surrounding radio wave usage conditions, such as the radio wave frequency and radio slot used by the surrounding radio terminal device PS. .

  Further, when installing the repeater device RS, it is only necessary to install it in a place where radio waves from the radio base station device CS can be received, and there is no need for initial setting for forming an antenna pattern optimum for the installation location. The installation time and labor can be saved. Furthermore, in order to change the antenna pattern, a mechanism that physically changes the direction and inclination of the antenna, for example, a tilt mechanism or a pan mechanism is not used. There is also an advantage that it is not necessary to provide a space and there are few restrictions on the installation location.

  In addition, this invention is not limited to the above structure, A various deformation | transformation is possible. For example, the antenna provided in the repeater apparatus RS described in the first embodiment is not separated for transmission and reception, but is separated for transmission and reception, or for a radio base station apparatus installed outdoors The antenna may be separated into a CS antenna and an antenna for the radio terminal apparatus PS installed indoors.

The figure which showed the structure of the radio | wireless communications system which concerns on embodiment of the repeater apparatus of this invention. The figure which showed the structure of the repeater apparatus which concerns on embodiment of this invention. The sequence diagram which shows the process which performs automatically changing the antenna pattern which the repeater apparatus which concerns on embodiment of this invention performs. The figure which showed the antenna pattern which concerns on embodiment of the repeater apparatus of this invention.

Explanation of symbols

NW ... Wireless communication network, CS, CS1, CS2 ... Wireless base station device, PS, PS1, PS2, PS3 ... Wireless terminal device, RS ... Repeater device, 11 ... Control unit, 12 ... Demodulation unit, 13 ... Modulation unit, 14 ... Amplification unit, 15 ... Power amplification unit, 16 ... Shared device

Claims (3)

A repeater device that relays wireless connection between a wireless base station device and a wireless terminal device connected to a wireless communication network,
A plurality of antennas for transmitting or receiving radio waves used for communication with the wireless base station device or the wireless terminal device;
Position determining means for periodically determining whether or not the wireless terminal device is located in a wirelessly communicable range based on a radio wave transmitted from the wireless terminal device connected to its own repeater device and received by the antenna;
An antenna that is a distribution of radio waves transmitted from the plurality of antennas so as to transmit radio waves to the radio terminal device when it is determined by the position determining means that the radio terminal apparatus is within a wirelessly communicable range. An antenna pattern control means for changing a pattern. The antenna pattern control means includes
A power amplifying unit for amplifying the power of radio waves transmitted from the antenna;
A phase shifter that changes the phase of the radio wave transmitted from the antenna;
The power amplification unit is instructed to transmit a radio wave to the position of the wireless terminal device determined by the position determination unit, and the phase shift amount is instructed to the phase shifter. The repeater apparatus according to 1. An interference avoidance determining means for determining whether it is necessary to avoid interference of radio waves by another wireless terminal device for wireless connection with the wireless terminal device connected to its own repeater device;
The antenna pattern control means transmits a radio wave to be transmitted to the radio terminal apparatus connected to its own repeater apparatus when it is determined by the interference avoidance judgment means that it is necessary to avoid radio wave interference by another radio terminal apparatus. The repeater apparatus according to claim 1, wherein a null point at which radio wave interference does not occur is formed at a position of another wireless terminal apparatus of the antenna pattern.

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