JP5790588B2 - Base station antenna device - Google Patents

Description

  The present invention relates to a base station antenna device for mobile communication.

  As a base station antenna apparatus for mobile communication, a cell in which a cell serving as a cover area is divided into a plurality of sectors and a sector antenna is provided so as to correspond to each sector is known.

  In the base station antenna apparatus, an interference suppression technique (ICIC, Inter-Cell Interference Coordination) at the cell boundary surface is required. An example of the interference suppression technique is an FFR (Fractional Frequency Reuse) technique that partially divides the frequency.

  The FFR technique is a technique for ensuring orthogonality between cell edge terminals of adjacent cells by determining a resource block group that can be used by a cell edge terminal (terminal existing at the cell edge) for each cell. In the base station antenna apparatus adopting the FFR technology, all the allocated frequencies are used in an area close to the base station where interference is low, but the allocated frequency is divided in a cell boundary region (cell edge) where there is much interference, and adjacent cells Inter-cell interference control is performed by using a different band at each cell edge.

  For example, there are Patent Documents 1 and 2 as prior documents using the FFR technique. In Patent Documents 1 and 2, reference signals (power, SNR, and the like) from a terminal are received by a plurality of sector antennas, and an assigned frequency is determined by discriminating a difference between reference signals with a threshold value.

JP 2010-288104 A JP 2008-61250 A JP2011-517528A JP 2009-44415 A JP-A-9-148981

Takeshi Hattori, Masanobu Fujioka, “Wireless Broadband HSPA + / LTE / SAE Textbook”, Impress R & D, Inc., July 27, 2009

  However, the above-described conventional method has a problem that the frequency utilization efficiency is poor.

  Specifically, for example, when the cell is configured with three sectors as shown in FIG. 6, the conventional base station antenna apparatus uses all the allocated frequencies in the area A near the base station, but other B , C, D areas, that is, the cell boundary region (cell edge) of each sector, each sector is adjacent to two cells, so the frequency band that can be used in one sector is 1/3, and the frequency utilization efficiency Will get worse.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a base station antenna apparatus capable of improving frequency utilization efficiency.

The present invention was devised to achieve the above object, and a cell serving as a cover area is divided into a plurality of sectors, and sector antennas provided so as to correspond to the sectors, and the sector antennas are controlled. A base station antenna apparatus comprising: a signal control unit that performs a radio signal conversion between an analog signal and a digital signal that is connected between the sector antenna and the signal control unit. Are configured to be able to communicate simultaneously at different frequencies, and are configured to be communicable with different directivities for each frequency, and the signal control unit is configured to determine the location of the terminal located in the cell based on the terminal location information received from the terminal. A terminal location information management unit that manages terminal location information, and each sector is divided into a plurality of areas having different allocation frequencies, and is managed by the terminal location information management unit A channel information unit that determines an area where a terminal that is a communication target is located from end position information and determines an allocation frequency according to the area where the terminal that is a communication target is located, and controls the directivity of the sector antenna The communication status between the directivity control unit and all terminals in the cell is managed, and the frequency used when communicating with the communication target terminal is set to the allocated frequency determined by the channel information unit. The sector antenna is controlled so that the directivity of the frequency used when communicating with the communication target terminal is directed to the communication target terminal via the directivity control unit. comprising a scheduler for controlling the said scheduler lower than the the communication target terminal is tight is allocated frequency area located communication capacity predetermined threshold When in the frequency to be used when communicating with the the communication target terminal, said the communication target terminal is a base station antenna apparatus for changing the frequency different from the assigned frequency of the area located.

  Each sector antenna is configured to be able to control directivity in a horizontal plane and directivity in a vertical plane for each frequency, and the terminal position information is three-dimensional information including a height position of the terminal, and the scheduler Through the directivity control unit, the sector antennas so that directivity in a horizontal plane and a vertical plane of a frequency used when communicating with the terminal to be communicated is directed to the terminal to be communicated. May be configured to control.

  The scheduler starts communication with the communication target terminal as a predetermined initial value of directivity in the vertical plane, and determines that the communication quality is not sufficient from the reference signal received from the communication target terminal. In this case, the sector antenna may be controlled so that the directivity in the vertical plane of the frequency used when communicating with the communication target terminal is directed to the communication target terminal.

  As the terminal location information, location information acquired by IMES (Indoor MEssaging System) may be used.

  The sector antenna is controlled by the channel information unit, and is controlled by the frequency control device that controls the frequency of transmission and reception, two or more antenna elements installed in the horizontal direction and the vertical direction, and the directivity control unit, A plurality of sets of phase shifters that control the directivity in the horizontal plane and in the vertical plane by controlling the feeding phase to each antenna element may be provided.

  The sector antenna may include a feed line including a transmission / reception signal amplification unit, and the feed line may be formed of a printed board.

  When the communication quality is not sufficient from the reference signal received from the terminal to be communicated, a gain control unit that controls the power supply voltage applied to the amplifier of the transmission / reception signal amplification unit to change the gain may be further provided.

  The scheduler uses a frequency used when communicating with the communication target terminal when the allocated frequency of the area where the terminal to be communicated is tight and the communication capacity is lower than a predetermined threshold. The frequency may be changed to a frequency different from the allocated frequency of the area where the target terminal is located.

  When the scheduler determines that communication quality is not sufficient from a reference signal received from the communication target terminal at the sector antenna in communication with the communication target terminal, the sector antenna of the adjacent sector The reference signals received from the communication target terminals may be compared, and switching may be performed so that the sector antenna having the best communication quality communicates with the communication target terminal.

  According to the present invention, the frequency utilization efficiency can be improved.

It is a figure which shows the base station antenna apparatus which concerns on one embodiment of this invention, (a) is a schematic block diagram, (b) is a schematic block diagram of a sector antenna, (c) is a schematic block diagram of a feed line, d) is a schematic block diagram of the signal controller. It is a figure which shows an example of the cell structure in the base station antenna apparatus of FIG. 1, and the frequency utilization condition in each area. It is a figure explaining operation | movement of the base station antenna apparatus of FIG. It is a figure explaining the effect of the base station antenna apparatus of FIG. 1, (a) is the allocation frequency which can be used for communication with each terminal with the base station antenna apparatus of this invention, (b) is the conventional base station antenna apparatus. It is a figure which shows the allocation frequency which can be used for communication with each terminal. In this invention, it is a figure explaining that a different allocation frequency can also be set also to a perpendicular direction. It is a figure which shows an example of the cell structure in the conventional base station antenna apparatus, and the frequency utilization condition in each area.

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

  FIG. 1 is a diagram illustrating a base station antenna apparatus according to the present embodiment, where (a) is a schematic configuration diagram, (b) is a schematic configuration diagram of a sector antenna, (c) is a schematic configuration diagram of a feed line, (D) is a schematic block diagram of a signal control part. FIG. 2 is a diagram illustrating an example of the cell configuration and the frequency usage status in each area.

  As shown in FIG. 1A, the base station antenna device 1 includes a sector antenna 2, a signal control unit (baseband unit) 3 that controls the sector antenna 2, and between the sector antenna 2 and the signal control unit 3. And a radio (RF) 4 that performs conversion between an analog signal and a digital signal.

  In the base station antenna apparatus 1, a cell serving as a cover area is divided into a plurality of sectors, and a sector antenna 2 is provided so as to correspond to each sector. One signal control unit 3 and one wireless device 4 are provided for each sector antenna 2. In this embodiment, as an example, a case where a cell is divided into three sectors as shown in FIG. 2 will be described. In this case, three sector antennas 2 are provided so as to correspond to the three sectors, and the signal control unit 3 and the radio device 4 are provided so as to correspond to the three sector antennas 2, respectively. In addition, since it is desirable that the base station antenna apparatus 1 has one housing for the signal control unit 3, the plurality of signal control units 3 provided so as to correspond to the sector antennas 2 are provided as one housing. It is desirable to be housed together.

  Each sector antenna 2 is configured to be able to communicate simultaneously at a plurality of frequencies, and is configured to be able to communicate with different directivities for each frequency. In the present embodiment, each sector antenna 2 is configured to be able to control the directivity in the horizontal plane and the directivity in the vertical plane for each frequency.

  Specifically, as shown in FIG. 1B, the sector antenna 2 includes a frequency control device 5 that controls a frequency to be transmitted and received, and two or more antenna elements 6 that are installed in the horizontal direction and the vertical direction, A plurality of sets of phase shifters 7 that control the directivity in the horizontal plane and in the vertical plane by controlling the feeding phase to each antenna element 6 are provided.

  In the present embodiment, three sets of the frequency control device 5, the antenna element 6, and the phase shifter 7 are provided in order to be able to communicate simultaneously at three different frequencies and to control the directivity at each of the three frequencies. In FIG. 1B, only one set of the frequency control device 5, the antenna element 6, and the phase shifter 7 is shown for simplification of the drawing. Hereinafter, the set of the frequency control device 5, the antenna element 6, and the phase shifter 7 is referred to as an antenna unit. The number of frequencies that can be simultaneously communicated (the number of antenna units) is not limited to this, and can be set as appropriate.

  As the frequency control device 5, for example, a variable band-pass filter or a diplexer can be used. A signal line 5 a extending from the signal control unit 3 is connected to the frequency control device 5, and the frequency control device 5 is directly controlled by a scheduler 22 (described later) of the signal control unit 3.

  In the present embodiment, the antenna element 6 has a first antenna element 6a extending in the vertical direction and a second antenna element 6b extending in the horizontal direction, and has a configuration of two elements whose polarization directions are different by 90 degrees. Using. However, the configuration of the antenna element 6 is not limited to this, and may be a single-element configuration, and the polarization direction can be changed as appropriate.

  Further, in this embodiment, two or more antenna elements 6 are installed in the horizontal direction and the vertical direction, respectively, so as to operate as an array antenna. By configuring in this way, it is possible to arbitrarily control the directivity in both the horizontal plane and the vertical plane by controlling the feeding phase of feeding power to each antenna element 6 by the phase shifter 7. A signal line 7 a extending from the signal control unit 3 is connected to the phase shifter 7, and the phase shifter 7 is directly controlled by a directivity control unit 21 (described later) of the signal control unit 3. Yes.

  Between each 1st antenna element 6a and the phase shifter 7, and between each 2nd antenna element 6b and the phase shifter 7, the feed line 8 containing a transmission / reception signal amplification part is provided. As shown in FIG. 1 (c), the feed line 8 includes two duplexers 9 for branching the downlink / uplink signal path, and the high-power amplifier 10 is provided in the signal path on the downlink side between the duplexers 9. The low-noise amplifier 11 is built in the signal path on the uplink side. In the present embodiment, the feeder line 8 is formed of a printed board.

  In the sector antenna 2, a radome 13 is provided so as to cover the entire frequency control device 5, antenna element 6, phase shifter 7, and feed line 8. A reflector 12 is provided in the radome 13, and a frequency control device 5, an antenna element 6, a phase shifter 7, and a feed line 8 are disposed in a space on the surface side of the reflector 12.

  As shown in FIG. 1D, the signal control unit 3 includes an interface (CPRI I / F) 14 for communicating with the radio device 4 and a demodulation processing unit (OFDM) that demodulates the signal received from the radio device 4. A demodulation processing unit 15, a modulation processing unit (OFDM modulation processing unit) 16 that modulates a signal to be transmitted, a reception processing unit (RXP) 17 that performs reception processing, and a transmission processing unit (TXP) 18 that performs transmission processing. And. Here, CPRI (Common Public Radio Interface) is used as the interface 14 and OFDM (Otrthogonal Frequency Division Multiplexing) transmission method is used as a communication method with the terminal (mobile phone terminal). The communication method is not limited to this.

  In base station antenna apparatus 1 according to the present embodiment, signal control unit 3 includes terminal location information management unit (HLR (Home Local Register)) 19, channel information unit (CSI (Channel Site Information)) 20, and directivity. Further, a control unit (PSC (Phase Shift Controller)) 21 and a scheduler (SCH (Scheduler)) 22 are further provided.

  The terminal location information management unit 19 manages terminal location information of terminals located in the cell based on the terminal location information received from the terminals, and stores the terminal location information of each terminal as a database. The terminal location information is normally managed by the HLR owned by each telecommunications carrier, but in this embodiment, the base station antenna apparatus 1 is equipped with a function equivalent to the HLR of each telecommunications carrier. The station antenna apparatus 1 manages terminal location information uniquely.

  In the present embodiment, three-dimensional information including the height position of the terminal is used as the terminal position information. Although the position information in the vertical direction is not included in each carrier's HLR, the terminal position information management unit 19 stores three-dimensional information including the height position of the terminal as a database.

  Information acquired by GPS (Global Positioning System) may be used as the position information of the latitude and longitude of the terminal. As the height position of the terminal (position information in the vertical direction), it is desirable to use information acquired by IMES (Indoor MEssaging System), which has been attracting attention as an indoor positioning method in recent years, because GPS information has low reliability.

  IMES is a plurality of IMES transmitters provided at different positions in the vertical direction, such as indoor floors, for example, and each IMES transmitter transmits information such as its own location information and the number of floors. It is one of the cell ID methods for identifying the nearest mobile phone base station by regarding the three-dimensional position information of the nearest IMES transmitter received at the terminal side as the terminal position, and a place where GPS radio waves do not reach, Alternatively, it is a technology that can give position information to a terminal even in a deep indoor or underground area where GPS radio waves are weak.

  The channel information unit 20 divides each sector into a plurality of areas having different allocation frequencies, determines the area where the terminal to be communicated is located from the terminal location information managed by the terminal location information management unit 19, and The allocated frequency is determined according to the area where the target terminal is located. The area and assigned frequency are set as shown in FIG. 2, for example. In FIG. 2, the drawing is simplified, and it seems that there is a gap between the areas, but in practice, the allocation frequency is set at all positions in the sector.

  The directivity control unit 21 is connected to the phase shifter 7 via the signal line 7 a, and controls the phase shifter 7 in accordance with the signal from the scheduler 22 to control the directivity of the sector antenna 2. is there.

  The scheduler 22 manages the communication status with all terminals in the cell. In the present embodiment, the scheduler 22 controls the sector antenna 2 so that the frequency used when communicating with the terminal to be communicated is the allocated frequency determined by the channel information unit 20, and the directivity control unit. The sector antenna 2 is controlled via the terminal 21 so that the directivity of the frequency used when communicating with the terminal to be communicated is directed to the terminal to be communicated.

  The signal line 5a connected to the frequency control device 5 is connected to the transmission processing unit 18, and the scheduler 22 uses one frequency among three antenna units of the sector antenna 2 via the transmission processing unit 18 and the signal line 5a. The control device 5 is controlled to control the frequency transmitted and received by the antenna unit.

  Further, in the present embodiment, the scheduler 22 sets the directivity in the vertical plane as the initial value (for example, the directivity toward the terminal when the height position of the terminal is 1 m from the ground). Directivity in the vertical plane of the frequency used when communicating with the terminal to be communicated when communication quality is determined to be insufficient from the reference signal received from the terminal to be communicated. Is configured to control the sector antenna 2 so as to be directed to the terminal to be communicated.

  As a reference signal used at this time, a quantitative signal such as SNR (Signal Noise Ratio) or received power may be used. When the value is equal to or less than a preset threshold value, it is determined that the communication quality is not sufficient. The scheduler 22 may be configured.

  Next, the operation of the base station antenna apparatus 1 will be described.

  As shown in FIG. 3, the terminal normally transmits its own location information (information acquired by GPS or the like) to the base station periodically (step S1). The terminal position information received by the sector antenna 2 of the base station antenna apparatus 1 is converted into a digital signal by the wireless device 4 and output to the signal control unit 3.

  The terminal position information received by the interface 14 of the signal control unit 3 is demodulated by the demodulation processing unit 15 and input to the reception processing unit 17. The terminal location information received by the reception processing unit 17 is sent from the reception processing unit 17 to the nearest exchange. In this embodiment, the terminal location information is also sent to the terminal location information management unit 19 in the signal control unit 3. The location of the terminal is also managed in the base station antenna apparatus 1.

  The terminal location information management unit 19 stores the input terminal location information and manages the location of the terminal (step S2). On the other hand, the terminal location information transmitted from the base station antenna apparatus 1 to the nearest exchange is registered in the HLR of each communication carrier from the exchange (step S3).

  The terminal location information management unit 19 and each carrier's HLR rewrites the database every time the location of the terminal changes. When there is a transmission addressed to the terminal, the switching center inquires of the HLR owned by each communication carrier and extracts the position (registration area) of the terminal.

  When communication with a terminal is started, the channel information unit 20 determines an area where the terminal to be communicated is located from the terminal position information managed by the terminal position information management unit 19, and the terminal to be communicated The assigned frequency is determined according to the area where the is located (step S4).

  After determining the allocated frequency, the scheduler 22 causes the directivity in the horizontal plane of the antenna unit used when communicating with the terminal to be communicated to be directed to the terminal to be communicated via the directivity control unit 21. The phase shifter 7 is controlled (step S5). At this time, the directivity in the vertical plane is set to an initial value.

  Thereafter, information is sent from the scheduler 22 to the transmission processing unit 18, modulated by the modulation processing unit 16, and then transmitted to the wireless device 4 via the interface 14. At that time, the allocated frequency information is directly transmitted from the transmission processing unit 18 to the frequency control device 5 in the sector antenna 2. The signal sent from the signal control unit 3 to the radio device 4 is converted into analog by the radio device 4 and transmitted from the sector antenna 2.

  Thereafter, the reference signal transmitted from the terminal in step S6 is received, and the reference signal is determined by the reception processing unit in the signal control unit 3 (step S7). The determination result is sent to the scheduler 22, and the scheduler 22 determines whether the value of the reference signal (the value determined in step S7) exceeds a preset threshold value (step S8).

  If the determination result in step S8 is YES, it is determined that communication is possible, the information is transmitted to the exchange, transmission data is created in the exchange (step S9), and data transmission (step S10) is performed. Communication is started (step S11).

  If the determination result in step S8 is NO, in order to improve communication quality, directivity adjustment in the vertical plane is performed in steps S11 and S12.

  In step S11, the height position (vertical position) of the terminal is searched. Specifically, the scheduler 22 transmits a command for acquiring position information by IMES to the terminal via the transmission processing unit 18, the modulation processing unit 16, the interface 14, the radio 4, and the sector antenna 2, and receives this command. The transmitted terminal transmits the three-dimensional position information including the height position received from the nearest IMES transmitter to the base station antenna apparatus 1. The three-dimensional position information received by the base station antenna device 1 is managed by the terminal position information management unit 19.

  In step S12, an antenna used when the scheduler 22 communicates with a terminal to be communicated via the directivity control unit 21 based on the information on the height position of the terminal included in the received three-dimensional position information. The phase shifter 7 is controlled so that the directivity in the vertical plane of the unit is directed to the terminal to be communicated. When communicating with a plurality of terminals using one antenna unit, the directivity in the vertical plane is strongest for a terminal close to a cell boundary that is susceptible to interference (a terminal farthest from the base station antenna apparatus 1). It is better to control the directivity.

  Thereafter, communication with the terminal is performed again, and a reference signal from the terminal is determined (steps S6 and S7). If it is determined that the value of the reference signal received in step S8 is greater than the threshold value, communication with the terminal is started via transmission data creation (step S9) and data transmission (step S10) at the exchange. (Step S11).

  Note that there may be a case where sufficient communication quality cannot be ensured even if the directivity in the vertical plane is controlled (that is, when NO is determined in step S8). In such a case, since signal degradation due to interference is considered, the signal control unit 3 is further provided with a gain control unit that controls the power supply voltage applied to the amplifiers 10 and 11 of the transmission / reception signal amplification unit of the feed line 8 to change the gain. It is desirable to improve communication quality by changing the gains of the amplifiers 10 and 11 in this gain control unit.

  The gain control unit controls the power supply voltage applied to the amplifiers 10 and 11 of the transmission / reception signal amplification unit of the feeder line 8 and changes the gain when the communication quality is not sufficient from the reference signal received from the terminal to be communicated. Composed. Since the gain control unit controls the amplifiers 10 and 11 with the additional voltage (power supply voltage), the antenna gain can be freely controlled with the same directivity by providing the gain control unit.

  In this embodiment, the transmission / reception processing units 17 and 18 are equipped with a function as a gain control unit, and the transmission / reception processing units 17 and 18 control the power supply voltages of the amplifiers 10 and 11. Note that even when the reference signal falls below the threshold value even though the terminal is not moving during communication, signal degradation due to interference can be considered. It is preferable to improve the communication quality by changing the gains of 10 and 11.

  If sufficient communication quality is not obtained even if the control by the gain control unit is performed, there may be an obstacle between the base station antenna apparatus 1 and the terminal. The terminal position information is sent to the station antenna device, the directivity is controlled so that the adjacent base station antenna device is directed to the terminal, the communication quality is similarly determined, and the base station antenna device having the best communication quality Make communication.

  Further, when the terminal moves to an area having a different allocated frequency during communication, the scheduler 22 controls the frequency control device 5 so as to change the communication frequency to the allocated frequency set in the area.

  Further, when the terminal moves to another sector during communication and the value of the reference signal from the terminal becomes equal to or less than the threshold value, communication is performed in the same procedure as described above with another sector antenna 2. .

  Specifically, when the scheduler 22 determines that the communication quality is not sufficient from the reference signal received from the communication target terminal at the sector antenna 2 in communication with the communication target terminal, Reference signals received from terminals to be communicated between the sector antennas 2 are compared, and switching is performed so that the sector antenna 2 having the best communication quality communicates with the terminals to be communicated. Thereby, even when the terminal moves between sectors, communication can be continued, and communication quality can be maintained.

  The same switching is performed when the terminal moves to another cell during communication. In this case, it is switched to the sector antenna of another base station antenna apparatus instead of the sector antenna 2 in the same base station antenna apparatus 1, but the operation is almost the same.

  In the vicinity of base station antenna apparatus 1 (area A in FIG. 2), MIMO communication is performed using a common frequency, and the speed can be increased. Further, in this embodiment, since the antenna element 6 having a two-element configuration in which the polarization directions are different by 90 degrees is used, it is possible to divide by not only the allocated frequency but also the polarization.

  The operation of the present embodiment will be described.

  In the base station antenna apparatus 1 according to the present embodiment, each sector antenna 2 is configured to be able to communicate simultaneously at a plurality of frequencies, and configured to be able to communicate with different directivities for each frequency. Based on the terminal position information received from the terminal, the terminal position information management unit 19 that manages the terminal position information of the terminal located in the cell, and each sector is divided into a plurality of areas having different allocated frequencies, thereby managing the terminal position information A channel information unit 20 for determining an area in which a terminal to be communicated is located from terminal location information managed by the unit 19 and determining an allocation frequency according to the area in which the terminal to be communicated is located; and a sector antenna The directivity control unit 21 that controls the directivity of 2 and the communication status between all terminals in the cell, and the frequency used when communicating with the terminal to be communicated is a channel. The sector antenna 2 is controlled so that the allocated frequency determined by the reporting unit 20 is obtained, and the directivity of the frequency used when communicating with the terminal to be communicated is set as the communication target via the directivity control unit 21. And a scheduler 22 that controls the sector antenna 2 so as to face the terminal.

  With this configuration, a plurality of frequencies can be used in the same sector, so that it is possible to improve the frequency utilization efficiency when communicating simultaneously with a plurality of terminals in the same sector.

  As an example, considering a case where communication is performed simultaneously with three terminals in the same sector, in the present invention, as shown in FIG. 4 (a), it is possible to make the allocated frequencies different among the three terminals. However, in the conventional method using the frequency of the same band in the same sector, as shown in FIG. 4B, when there are three terminals in the sector, the frequency utilization efficiency is 1 compared to the case of one terminal. / 3. That is, in this case, according to the present invention, it is possible to realize a frequency utilization efficiency of up to three times that of the conventional method.

  In this embodiment, since the terminal location information management unit 19 is provided in the base station antenna apparatus 1 to manage the terminal location information of the terminal, when determining the assigned frequency or controlling the directivity In addition, it is not necessary to communicate with the exchange every time, and the processing speed can be increased.

  In the base station antenna apparatus 1, each sector antenna 2 is configured such that the directivity in the horizontal plane and the directivity in the vertical plane can be controlled for each frequency, and the scheduler 22 is connected via the directivity control unit 21. The sector antenna 2 is controlled so that the directivity in the horizontal plane and the vertical plane of the frequency used when communicating with the terminal to be communicated is directed to the terminal to be communicated.

  This makes it possible to optimize not only the horizontal plane but also the directivity in the vertical plane, thereby improving communication quality and enabling higher-density communication. Also, in recent years, with the reduction of the coverage area such as femtocells, interference suppression technology within the same base station has become important, but by controlling the directivity in the vertical plane, more precise Interference control can be performed.

  Further, like the base station antenna apparatus 1 according to the present embodiment, a plurality of antenna elements 6 are arranged in the vertical direction so that the directivity in the vertical plane can be controlled, so that from the underground to about several hundred meters above the ground. Area can be covered, directivity within the vertical plane where the received power from the terminal is maximized can be formed, and communication quality can be improved.

  Further, the base station antenna apparatus 1 uses position information acquired by IMES as terminal position information. In the past, it was common to use only GPS position detection, so the height position of the terminal could not be detected accurately. For example, the same position when the terminal is in the ground and several hundred meters above the ground Although it has become information, the position in the height direction of the terminal can be obtained with high accuracy by using IMES.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, a case has been described in which the assigned frequency is set to a fixed value for each terminal position (for each area). However, the assigned frequency may be changed as needed depending on the frequency usage situation (degree of tightness, etc.) It may be.

  In this case, the scheduler 22 determines the frequency used when communicating with the terminal to be communicated when the allocated frequency of the area where the terminal to be communicated is tight and the communication capacity falls below a predetermined threshold. What is necessary is just to comprise so that it may change to the frequency different from the allocation frequency of the area where the terminal which becomes object is located. By configuring in this way, it is possible to determine the frequency to be used according to the frequency tightness, so that it is possible to further improve the frequency utilization efficiency.

  In the above embodiment, the area for each assigned frequency is partitioned in a two-dimensional space (only latitude and longitude). However, the area is partitioned in a three-dimensional space including the height position, and different allocations are also made in the vertical direction. The frequency may be set. As a result, for example, as shown in FIG. 5, even when communicating simultaneously with a plurality of terminals existing on different floors of the same building, communication using a plurality of frequencies becomes possible, and the frequency utilization efficiency is further improved. It becomes possible to improve.

  Moreover, although the case where the terminal location information management unit 19 is provided in each of the plurality of signal control units 3 has been described in the above embodiment, the present invention is not limited thereto, and the terminal location information management unit 19 is shared by each signal control unit 3. It is good.

  Furthermore, in the above embodiment, the information on the height position of the terminal is acquired by IMES, but the method for detecting the height position of the terminal is not limited to this. For example, the sector antenna 2 is moved up and down two blocks. It is also possible to receive a signal from the terminal and to detect the height position of the terminal from the phase shift information and delay time of the signal.

DESCRIPTION OF SYMBOLS 1 Base station antenna apparatus 2 Sector antenna 3 Signal control part 4 Radio device 5 Frequency control apparatus 6 Antenna element 7 Phase shifter 8 Feed line 9 Duplexer 10 High output amplifier 11 Low noise amplifier 12 Reflector 13 Radome 14 Interface 15 Demodulation processing part 16 Modulation processing unit 17 Reception processing unit 18 Transmission processing unit 19 Terminal position information management unit 20 Channel information unit 21 Directivity control unit 22 Scheduler

Claims (8)

A cell serving as a cover area is divided into a plurality of sectors, and a sector antenna provided to correspond to each sector,
A signal control unit for controlling the sector antenna;
In a base station antenna device comprising a radio that is connected between the sector antenna and the signal control unit and converts an analog signal and a digital signal,
Each sector antenna is configured to be able to communicate simultaneously at a plurality of frequencies, and configured to be able to communicate with different directivities for each frequency,
The signal controller is
Based on the terminal location information received from the terminal, a terminal location information management unit that manages the terminal location information of the terminal located in the cell;
Each sector is divided into a plurality of areas having different allocation frequencies, and from the terminal location information managed by the terminal location information management unit, the area where the terminal to be communicated is located is determined, and the terminal to be communicated is A channel information section for determining an allocated frequency according to the area where it is located;
A directivity control unit for controlling the directivity of the sector antenna;
The communication status with all terminals in the cell is managed, and the sector antenna is controlled so that the frequency used when communicating with the communication target terminal becomes the allocated frequency determined by the channel information unit A scheduler that controls the sector antenna so that the directivity of the frequency used when communicating with the terminal to be communicated is directed to the terminal to be communicated via the directivity control unit,
Equipped with a,
The scheduler uses a frequency used when communicating with the communication target terminal when the allocated frequency of the area where the terminal to be communicated is tight and the communication capacity is lower than a predetermined threshold. A base station antenna apparatus, wherein the frequency is changed to a frequency different from an allocated frequency of an area where a target terminal is located . Each sector antenna is configured to be able to control the directivity in the horizontal plane and the directivity in the vertical plane for each frequency,
The terminal position information is three-dimensional information including the height position of the terminal,
The scheduler, through the directivity control unit, directs the directivity in the horizontal plane and the vertical plane of the frequency used when communicating with the terminal to be communicated toward the terminal to be communicated. The base station antenna apparatus according to claim 1, wherein the base station antenna apparatus is configured to control a sector antenna. The scheduler starts communication with the communication target terminal as a predetermined initial value of directivity in the vertical plane, and determines that the communication quality is not sufficient from the reference signal received from the communication target terminal. 3. The sector antenna is configured to control a directivity within a vertical plane of a frequency used when communicating with the terminal to be communicated toward the terminal to be communicated. Base station antenna device. The base station antenna apparatus according to claim 2, wherein position information acquired by IMES (Indoor MEssaging System) is used as the terminal position information. The sector antenna is controlled by the channel information unit, and is controlled by the frequency control device that controls the frequency of transmission and reception, two or more antenna elements installed in the horizontal direction and the vertical direction, and the directivity control unit, 5. The base station antenna device according to claim 2, comprising a plurality of sets of phase shifters that control directivity in a horizontal plane and a vertical plane by controlling a feeding phase to each antenna element. . The sector antenna includes a feed line including a transmission / reception signal amplifier,
The base station antenna device according to claim 5, wherein the feed line is formed of a printed circuit board. The base according to claim 6, further comprising: a gain control unit that controls a power supply voltage applied to an amplifier of the transmission / reception signal amplification unit to change a gain when communication quality is not sufficient from a reference signal received from the terminal to be communicated. Station antenna device. When the scheduler determines that communication quality is not sufficient from a reference signal received from the communication target terminal at the sector antenna in communication with the communication target terminal, the sector antenna of the adjacent sector comparing the reference signals received from the the communication target terminal among, according to any one of claims 1 to 7 for switching to communicate with most communication quality the be communicated in good said sector antenna terminal Base station antenna device.