JP2008277973A - Mobile communication system, and base station device and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce radio wave interference from a terminal station communicating with a nearby base station. <P>SOLUTION: A base station 12 includes: an interference signal detector 34 which detects an interference signal causing interference with a channel used for communication with a base station based upon a reception signal; an interference channel information generator 36 which generates interference channel information indicative of the channel of the interference signal; and an interference information transmission control 38 which transmits the interference channel information to a nearby base station 12 in sequence until the electric power of the interference signal detected by the interference signal detector 34 is reduced. The base station 12 further includes: an interference channel information acquisition unit 40 which acquires the interference channel information and discriminates whether the interference channel information is addressed to the base station 12 itself; an in-use channel decision unit 42 which decides whether the channel that the interference channel information addressed to the base station itself indicates is used; and a channel assignment unit 44 which changes assignment of channels. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile communication system, a base station apparatus, and a control method thereof, and more particularly, to a technique for reducing radio wave interference from a terminal station that communicates with a nearby base station (hereinafter referred to as a “closed base station”).

  In a mobile terminal system using the cell system, a large number of base stations whose radio wave coverage is limited to a certain range are arranged so that the same frequency can be used repeatedly between base stations. For this reason, each base station may receive radio wave interference from a terminal station that communicates with its neighboring base stations.

  Specifically, in the mobile communication system 70 shown in FIG. 8, a terminal station 74-6 communicating with a base station adjacent to the base station 72-1 (hereinafter referred to as “adjacent base station”) 72-2 is connected to both base stations. When the station cells 76-1 and 76-2 move to an overlapping area, radio waves transmitted from the terminal station 74-6 may reach not only the base station 72-2 but also the base station 72-1. Here, if the mobile communication system 70 employs an OFDMA (Orthogonal Frequency Division Multiple Access) system, the received signal spectrum at the base station 72 is, for example, as shown in FIG. As shown in the figure, the radio waves transmitted from the terminal station 74-6 out of carrier synchronization with the base station 72-1 are transmitted from the terminal stations 74-1 to 7-5 communicating with the base station 72-1. The orthogonality of each subcarrier in the received wave is broken. If this happens, the base station 72-1 cannot correctly demodulate the received signals from the terminal stations 74-1 to 7-5 by Fast Fourier Transform (FFT). FIG. 10 is a diagram showing a demodulation constellation by the base station 72-1 in this case. As shown in the figure, due to interference interference from the terminal station 74-6, EVM (Error Vector Magnitude) causes the terminal station 74-3 <terminal station 74-4 <terminal station 74-1 <terminal station 74-2≈. It becomes the terminal station 74-5.

As a countermeasure technique for such radio wave interference, for example, in Patent Document 1, OFDM that realizes high-speed transmission and MC-CDMA that has high resistance to interference signals are used in slot units according to the propagation state and communication environment, and communication is performed. A wireless communication system for improving capacity is disclosed.
JP 2004-158901 A

  However, the technique and other techniques described in Patent Document 1 (for example, the adaptive array antenna technique) can suppress the occurrence of radio wave interference even though it can avoid radio wave interference and prevent deterioration in communication quality. I couldn't.

  The present invention has been made in view of the above-described conventional problems, and provides a mobile communication system, a base station apparatus, and a control method thereof that can reduce radio wave interference from a terminal station communicating with a neighboring base station. With the goal.

  In order to solve the above problems, a mobile communication system according to the present invention is a mobile communication system including a plurality of base station devices that communicate with terminal station devices in its own cell, wherein each base station device receives a received signal. Based on the interference signal detecting means for detecting an interference signal that interferes with a channel used for communication with the terminal station apparatus, and until the power of the interference signal detected by the interference signal detecting means is reduced. Interference channel information transmitting means for sequentially transmitting interference channel information indicating a signal channel to adjacent base station devices (adjacent base station devices), and receiving the interference channel information addressed to the own station Is characterized by changing the allocation of the channel when the channel indicated by the interference channel information is used.

  According to the present invention, the base station apparatus detects an interference signal that interferes with a channel used for communication based on the received signal. Then, until the power of the detected interference signal is reduced, the adjacent base station apparatus is sequentially notified of interference channel information indicating the channel of the interference signal via a wired line or a wireless line. On the other hand, the base station apparatus that has received the interference channel information allocates the channel when the received interference channel information is addressed to the own station and the channel indicated by the interference channel information is used. change. For this reason, the base station apparatus can reduce radio wave interference from the terminal station apparatus communicating with the neighboring base station apparatus without specifying the arrival direction of the interference wave.

  In one aspect of the present invention, the interference channel information transmitting unit transmits the interference channel information at a predetermined timing for identifying a base station apparatus that is a transmission destination, and the base station apparatus that has received the interference channel information Based on the reception timing of the interference channel information, it is determined whether or not the interference channel information is addressed to the own station. According to this aspect, only the base station apparatus corresponding to the transmission timing of the interference channel information changes the channel assignment indicated by the interference channel information. For this reason, the base station apparatus can reduce radio wave interference from the terminal station apparatus communicating with the neighboring base station apparatus while preventing an increase in the number of channel changes by the neighboring base station apparatus.

  In this aspect, each base station apparatus communicates with the terminal station apparatus by a time division duplex method, and the predetermined timing may be a predetermined reception frame by time division duplex. This eliminates the need to provide a special circuit for receiving interference channel information in the base station apparatus.

  In one aspect of the present invention, the interference channel information transmitting unit transmits the interference channel information including base station identification information for identifying a base station apparatus that is a transmission destination, and receives the interference channel information. The apparatus identifies whether or not the interference channel information is addressed to itself based on base station identification information included in the interference channel information.

  In this aspect, each base station apparatus has the power of the interference signal related to the channel indicated by the interference channel information immediately after transmitting the interference channel information to the base station apparatus for each adjacent base station apparatus. Further comprising interference reduction record information storage means for storing interference reduction record information indicating the number of times of reduction, the interference channel information transmitting means based on the interference reduction record information stored in the interference reduction record information storage means, You may determine the transmission order to the base station apparatus which is a transmission destination of interference channel information. In this way, the base station apparatus can preferentially transmit the interference channel information to the adjacent base station apparatus where the terminal station apparatus in the cell tends to be an interference source. For this reason, it is possible to reduce radio wave interference from the terminal station apparatus communicating with the neighboring base station apparatus while preventing an increase in the number of channel changes by the neighboring base station apparatus.

  Further, in one aspect of the present invention, each base station apparatus performs radio communication with the terminal station apparatus using an orthogonal frequency division multiple access scheme and a time division multiple redundancy scheme, and is used for communication with the terminal station apparatus. A channel is specified by a subcarrier frequency by orthogonal frequency division and a time slot by time division multiplexing. According to this aspect, in a mobile communication system employing an orthogonal frequency division multiple access scheme and a time division multiple redundancy scheme, a base station apparatus communicates with a neighboring base station apparatus without specifying the arrival direction of an interference wave Radio wave interference from the station apparatus can be reduced.

  The base station apparatus according to the present invention is a base station apparatus that communicates with a terminal station apparatus in its own cell, and interferes with a channel used for communication with the terminal station apparatus based on a received signal. Interference signal detection means for detecting an interference signal and interference channel information indicating the channel of the interference signal are sequentially transmitted to adjacent base station apparatuses until the power of the interference signal detected by the interference signal detection means is reduced. Interfering channel information transmitting means.

  The base station apparatus according to the present invention is a base station apparatus that communicates with a terminal station apparatus in its own cell, and is an interference signal that interferes with communication of the other base station apparatus from another base station apparatus Interference channel information receiving means for receiving the interference channel information indicating the channel of the channel, and the interference channel information received by the interference channel information receiving means is addressed to the own station and using the channel indicated by the interference channel information And channel allocating means for changing the channel allocation.

  The base station apparatus control method according to the present invention is a base station apparatus control method for communicating with a terminal station apparatus in its own cell, and is used for communication with the terminal station apparatus based on a received signal. An interference signal detecting step for detecting an interference signal that interferes with a channel to be interfered, and interference channel information indicating the channel of the interference signal until the power of the interference signal detected in the interference signal detecting step is reduced. An interference channel information transmission step of sequentially transmitting to the station device.

  The base station apparatus control method according to the present invention is a base station apparatus control method for communicating with a terminal station apparatus in its own cell, and communication from the other base station apparatus to another base station apparatus is performed. An interference channel information reception step for receiving interference channel information indicating a channel of an interference signal that interferes with the interference channel information, and the interference channel information received in the interference channel information reception step is addressed to the own station and indicated by the interference channel information. And a channel assignment step for changing the assignment of the channel when using the channel.

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

  FIG. 1 is an overall configuration diagram of a mobile communication system 10 according to an embodiment of the present invention. As shown in the figure, the mobile communication system 10 includes a plurality of base stations 12 (only the base stations 12-1 to 7 are shown here) and a plurality of terminal stations 14 (not shown). Yes. The terminal station 14 is, for example, a portable cellular phone, a portable information terminal, or a data communication card.

  As shown in FIG. 1, each base station 12 is arranged such that an end (cell edge) of a cell 16 indicating a communication coverage area overlaps an end of its adjacent cell. For example, the cell 16-1 of the base station 12-1 has areas overlapping with the cells 16-2 to 7-7 of the adjacent base stations 12-2 to 7-7, respectively. Each base station 12 transmits / receives a radio signal to / from a terminal station 14 located in the own cell using a TDD (Time Division Duplex) method, and also uses OFDMA (Orthogonal Frequency Division Multiple Access). Multiplex communication is performed by a multiple access) method and a TDMA (Time Division Multiple Access) method.

  FIG. 2 is a diagram illustrating an example of a channel configuration in the mobile communication system 10. RX and TX in the figure respectively indicate a reception frame and a transmission frame of the base station 12, and each frame is composed of a plurality of time slots (here, four slots) by time division multiplexing. Further, for each time slot, a plurality of subchannels (here, 10 subchannels) composed of a plurality of subcarriers (for example, 16 subcarriers) by orthogonal division multiplexing are defined. A channel used for each communication is specified by a combination of a slot number (Slot 1 to 4) for identifying a time slot and a sub-channel number (f1 to f10) for identifying a sub-channel frequency. In the mobile communication system 10, the same frequency is reused by causing each base station 12 to use each channel specified in this way. Note that “ICH” shown in FIG.

  Also, each base station 12 detects an interference signal that interferes with a channel used for communication with the terminal station 14 in its own cell based on the received signal. The interference channel information indicating the channel of the interference signal is sequentially transmitted to the adjacent base station 12 until the power of the detected interference signal is reduced. On the other hand, the base station 12 that has received the interference channel information from the adjacent base station 12 uses the channel indicated by the interference channel information when the received interference channel information is addressed to the own station. Change the channel assignment. In this way, in the mobile communication system 10, the base station 12 that has detected the interference signal reduces radio wave interference from the terminal station 14 that communicates with the adjacent base station 12 without specifying the arrival direction of the interference wave. It has become.

  Below, the structure and function with which the base station 12 is provided in order to implement | achieve the said process are demonstrated in detail.

  FIG. 3 is a block diagram of the base station 12. As shown in the figure, the base station 12 includes an antenna 20, a switching unit 22, a receiving unit 24, a transmitting unit 26, a signal processing unit 28, an I / F unit 30, and a control unit 32.

  The antenna 20 radiates a radio signal supplied from the transmission unit 26, receives a radio signal transmitted from the terminal station 14 or the adjacent base station 12, and outputs the received radio signal to the reception unit 24. .

  The switching unit 22 switches transmission / reception of the antenna 20 in a time division manner. Specifically, the connection destination of the antenna 20 is switched to the reception unit 24 or the transmission unit 26 so that the radio signal is received by the reception frame (RX) and the radio signal is transmitted by the transmission frame (TX). However, this is not the case when interference channel information described later is transmitted in the received frame.

  The receiving unit 24 down-converts a radio signal received by the antenna 20 into a baseband signal and outputs it to the signal processing unit 28.

  The transmission unit 26 up-converts the baseband signal input from the signal processing unit 28 into a radio signal, amplifies the signal to a transmission output level, and supplies the signal to the antenna 20.

  The signal processing unit 28 extracts data transmitted from the terminal station 14 or the adjacent base station 12 from the baseband signal input from the receiving unit 24. Specifically, the baseband signal input from the receiving unit 24 is subjected to symbol synchronization, guard interval removal, conversion to a digital signal, and the like, and the obtained digital signal is further subjected to fast Fourier transform ( FFT) is converted into a complex symbol sequence representing the phase and amplitude of each subcarrier. Then, the complex symbol sequence is converted into corresponding binary data by demapping processing according to the modulation method, and data transmitted from the terminal station 14 or the adjacent base station 12 is obtained. The extracted data is output to the I / F unit 30 or the control unit 32.

  The signal processing unit 28 converts data input from the I / F unit 30 or the control unit 32 into a baseband signal. Specifically, binary data input from the I / F unit 30 or the control unit 32 is converted into a complex symbol sequence representing the phase and amplitude of each subcarrier by mapping processing according to the modulation method. Then, the complex symbol sequence is converted into a digital signal by inverse fast Fourier transform (IFFT), and further converted into an analog signal and a guard interval is added to obtain a baseband signal. The baseband signal thus obtained is supplied to the transmission unit 26.

  The I / F unit 30 outputs data input from a host device (not shown) to the signal processing unit 28 and outputs data input from the signal processing unit 28 to the host device.

  The control unit 32 includes a CPU and a memory, and controls each unit of the base station 12. In addition, as a functional configuration related to transmission of interference channel information, which will be described later, it has an interference signal detection unit 34, an interference channel information creation unit 36, and an interference channel information transmission control unit 38, and as a functional configuration related to reception of interference channel information, It has an interference channel information acquisition unit 40, a used channel determination unit 42, and a channel allocation unit 44. These functions are realized by the CPU executing various control programs stored in the memory.

  Based on the received signal (here, each carrier component of the complex symbol input from the signal processing unit 28), the interference signal detection unit 34 sets the channel used for communication with the terminal station 14 in its own cell according to a predetermined algorithm. It detects an interference signal that gives interference. As an algorithm for detecting the interference signal, for example, zero forcing equalization and other equalization techniques are applied.

  The interference channel information creation unit 36 creates interference channel information including a slot number and a subchannel number for identifying a channel of the interference signal when the interference signal detection unit 34 detects an interference signal.

  The interference channel information transmission control unit 38 is a frame (timing) in which the interference channel information created by the interference channel information creation unit 36 is allocated to the own station until the power of the interference signal detected by the interference signal detection unit 34 is reduced. ) To control the signal processing unit 28 so that it is sequentially transmitted to the adjacent base station 12. Specifically, the signal processing unit 28 is controlled so that the interference channel information is transmitted at the following timing.

  FIG. 4 is a frame configuration example showing allocation of frames used for transmission of interference channel information. Here, when the mobile communication system 10 has a cell configuration in which six adjacent base stations 12 are arranged around a certain base station 12 (see FIG. 1), each of the seven adjacent base stations 12 is 7 An example is shown in which frames are assigned so that interference channel information can be transmitted for each frame (see the lower part of FIG. 4). That is, base station 12-1 transmits interference channel information in frame 1, base station 12-2 transmits interference channel information in frame 2,..., Base station 12-7 transmits interference channel information in frame 7. The transmission timing of the interference channel information is defined in advance according to the transmission source. When the interference channel information transmission control unit 38 controls the transmission timing of the interference channel information according to such a frame configuration, the adjacent base stations 12 do not transmit the interference channel information at the same timing.

  Further, in the frame configuration example shown in the figure, the above seven frames are set as one superframe and the seven superframes are set as one superframe group, and interference is performed based on the superframe (timing) in which interference channel information is transmitted (received). The transmission destination of the channel information can be identified (see the upper part of FIG. 4). That is, the interference channel information addressed to the base station 12-1 is transmitted in superframe 1, the interference channel information addressed to the base station 12-2 is transmitted in superframe 2,..., The interference addressed to the base station 12-7 The transmission timing of the interference channel information is defined in advance according to the transmission destination, such that the channel information is transmitted in the super frame 7. The interference channel information transmission control unit 38 controls the transmission timing of the interference channel information according to the superframe configuration, so that it is not necessary to include information indicating the transmission destination in the interference channel information, and the interference channel information is addressed to the adjacent base station 12. Are sequentially transmitted at predetermined intervals (every 7 frames).

  As shown in FIG. 2, the interference channel information transmission control unit 38 receives interference channel information in a predetermined reception time slot of the reception frame (here, RX slot 3 expressed as ICH) in the frame allocated to the own station. May be controlled so that the signal processing unit 28 and the switching unit 22 are transmitted. In this way, when a certain base station 12 transmits interference channel information, all the adjacent base stations 12 are in a reception mode of interference channel information, so that each base station 12 has a special circuit for receiving interference channel information. Need not be provided.

  Further, in the frame configuration example in FIG. 4, the transmission destination of the interference channel information is defined for each super frame, and the transmission source of the interference channel information is defined for each frame in the super frame. The transmission source of interference channel information may be defined for each frame, and the transmission destination of interference channel information may be defined for each frame in the superframe.

  The interference channel information acquisition unit 40 acquires the interference channel information transmitted from any adjacent base station 12 and the reception timing thereof from the signal processing unit 28, and the acquired interference channel information is based on the reception timing. This is to identify whether or not it is addressed to its own station. Specifically, when the reception timing belongs to which superframe in the channel configuration shown in FIG. 4 and the transmission destination corresponding to the specified superframe matches the own station, the interference channel information is Identify that it is addressed to your station.

  When the interference channel information acquired by the interference channel information acquisition unit 40 is addressed to the own station, the used channel determination unit 42 selects a channel specified by the slot number and subchannel number included in the interference channel information. It is determined whether or not the own station is using it.

  The channel allocation unit 44 changes the channel allocation when the use channel determination unit 42 determines that the own station is using the channel indicated by the interference channel information. For example, another vacant channel is assigned to the communication using the channel indicated by the interference channel information, the channel indicated by the interference channel information is assigned to communication with another terminal station 14, or the channel indicated by the interference channel information is used. Or temporarily stop.

  Next, the operation of the base station 12 will be described with reference to FIGS.

  FIG. 5 is a flowchart showing processing relating to transmission of interference channel information in the base station 12 (here, the base station 12-1 in FIG. 1). This process is activated for each received frame.

  As shown in the figure, when a radio signal is received (S100), the interference signal detector 34 is connected to the terminal station 14 in its own cell based on each carrier component of the complex symbol input from the signal processor 28. An interference signal that interferes with the channel used for the communication is detected (S102). Here, if no interference signal is detected, the base station 12-1 ends this processing. On the other hand, when an interference signal is detected in S102, the interference channel information creating unit 36 creates interference channel information including a slot number and a subchannel number for identifying the channel of the interference signal (S104).

  Next, the interference channel information transmission control unit 38 initializes the counter i to 1 (S106). Then, the signal processing unit 28 and the switching unit 22 are controlled so that the interference channel information created in S104 is transmitted to the i-th adjacent base station among the six adjacent base stations 12-2 to 12-7. 26 transmits the interference channel information (S108). For example, when the i-th adjacent base station is the base station 12-2, in the frame 1 (transmission source: base station 12-1) assigned to the own station in the super frame 2 (transmission destination: base station 12-2). Interference channel information is transmitted in a predetermined reception time slot.

  Thereafter, the interference signal detection unit 34 checks whether or not the power of the interference signal detected in S102 has been reduced (S110). Here, when the confirmation of the reduction of the interference signal power is detected, the base station 12-1 ends this processing. On the other hand, if the reduction of the interference signal power is not confirmed, the interference channel information transmission control unit 38 adds 1 to the counter i (S112) until the counter i exceeds the number of adjacent base stations n (here, 6) ( (S114), the processes after S108 are repeatedly executed. That is, the interference channel information created in S104 is repeatedly transmitted until the power of the interference signal detected in S102 is reduced or until it is transmitted to all adjacent base stations 12-2 to 7.

  FIG. 6 is a flowchart showing processing relating to reception of interference channel information in the base station 12 (here, the base station 12-2 in FIG. 1). This process is started for each received frame or in a received frame (in this case, a received frame in the super frame 2) in which interference channel information addressed to the own station can be transmitted.

  As shown in the figure, when the interference channel information is received (S200), the base station 12-2 performs carrier sense in an empty channel (S202). Next, the interference channel information acquisition unit 40 acquires the interference channel information transmitted from any of the adjacent base stations 12 and the reception timing thereof from the signal processing unit 28, and whether or not the interference channel information is addressed to the own station. That is, it is determined whether or not the reception timing of the reception channel information is within a super frame (in this case, super frame 2) having the own station as the transmission destination (S204). Here, if the reception timing is not within the superframe of the own station, the base station 12-2 determines that the interference channel information received in S200 is addressed to another station, and ends this processing.

  On the other hand, if it is determined in S204 that the reception timing of the interference channel information is within the superframe of the own station, the used channel determination unit 42 is specified by the slot number and subchannel number included in the interference channel information. It is determined whether or not the own station is using the channel (S206). If the channel is not used, the base station 12-2 determines that there is no interference source among the terminal stations 14 in communication with the own station, and ends this processing. On the contrary, if it is determined that the channel is used, the base station 12-2 determines that the terminal station 14 performing communication using the channel is an interference source, and the carrier in S202 Based on the sense result, another empty channel is allocated to the terminal station 14 (S208).

  According to the mobile communication system 10 described above, the base station 12 that has detected the interference signal can reduce radio wave interference from the terminal station 14 that communicates with the adjacent base station 12 without specifying the arrival direction of the interference wave. Can do.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible.

  For example, in the above embodiment, the present invention is applied to a mobile communication system that employs the OFDMA scheme and the TDMA / TDD scheme. However, the present invention is also applicable to a mobile communication system that employs other multiple access schemes.

  Further, in the mobile communication system 10 according to the above embodiment, the base station 12 that has received the interference channel information identifies whether or not the interference channel information is addressed to itself based on the reception timing. Transmits the interference channel information including the base station ID for identifying the transmission destination by the base station 12 that has detected the interference signal, and the base station 12 that has received the interference channel information has the base station ID included in the interference channel information and You may make it identify whether this interference channel information is addressed to an own station by comparing with the base station ID of an own station.

 In this case, for each adjacent base station 12, the base station 12 transmits the interference channel information addressed to the adjacent base station 12 immediately after transmitting the interference channel information, and the interference reduction indicating the number of times the power of the interference signal indicated by the interference channel information is reduced. Actual information (number of times, frequency, probability, etc.) may be stored in a storage unit such as a memory (see FIG. 7), and a transmission destination of interference channel information may be determined based on the information. In this way, the interference channel information can be preferentially transmitted to the adjacent base station 12 where the terminal station 14 in the cell is likely to be an interference source.

  Further, the base station 12 includes a configuration related to the transmission of the interference channel information (interference signal detection unit 34, interference channel information creation unit 36, interference channel information transmission control unit 38) and a configuration related to reception thereof (interference channel information acquisition unit). 40, the used channel determination unit 42, and the channel allocation unit 44). In this case, since the base station 12 having only the configuration related to the transmission of the interference channel information does not change the channel assignment in response to the reception of the interference channel information, the base station 12 having only the configuration related to the reception of the interference channel information. In comparison, the communication priority is relatively high.

  Further, the base station 12 that has detected the interference signal transmits the interference channel information not only to the adjacent base station 12 but also to the adjacent base station 12 located in a range where the terminal station 14 in the cell can be an interference source. Transmission may be performed (proximity range ≧ adjacent range). In this case, the number of frames included in one superframe and the number of superframes included in one superframe group are equal to or greater than the number of base stations that are close to each other.

1 is an overall configuration diagram of a mobile communication system according to an embodiment of the present invention. It is a figure which shows an example of the channel structure which concerns on embodiment of this invention. It is a block diagram of the base station which concerns on embodiment of this invention. It is a frame structural example which shows allocation of the frame used for transmission of interference channel information. It is a flowchart which shows the process which concerns on transmission of the interference channel information in a base station. It is a flowchart which shows the process which concerns on reception of the interference channel information in a base station. It is a figure which shows an example of the memory | storage part which memorize | stores interference reduction performance information. 1 is an overall configuration diagram of a mobile communication system. It is a figure which shows an example of the received signal spectrum in the base station at the time of radio wave interference. It is a figure which shows an example of the demodulation constellation by the base station at the time of radio wave interference.

Explanation of symbols

  10, 70 mobile communication system, 12, 72 base station, 14, 74 terminal station, 16, 76 cells (cover area), 20 antenna, 22 switching unit, 24 receiving unit, 26 transmitting unit, 28 signal processing unit, 30 I / F section, 32 control section, 34 interference signal detection section, 36 interference channel information creation section, 38 interference channel information transmission control section, 40 interference channel information acquisition section, 42 used channel determination section, 44 channel allocation section.

Claims (10)

A mobile communication system including a plurality of base station devices that communicate with terminal station devices in its own cell,
Each of the base station devices
An interference signal detecting means for detecting an interference signal that interferes with a channel used for communication with the terminal station device, based on a received signal;
Interference channel information transmitting means for sequentially transmitting interference channel information indicating a channel of the interference signal to neighboring base station apparatuses until power of the interference signal detected by the interference signal detecting means is reduced,
The base station apparatus that has received the interference channel information addressed to the own station,
Changing the channel assignment when using the channel indicated by the interference channel information;
A mobile communication system. The mobile communication system according to claim 1, wherein
The interference channel information transmitting means transmits the interference channel information at a predetermined timing for identifying a base station apparatus that is a transmission destination,
The base station apparatus that has received the interference channel information identifies whether or not the interference channel information is addressed to itself based on the reception timing of the interference channel information.
A mobile communication system. The mobile communication system according to claim 2,
Each base station device communicates with the terminal station device by a time division duplex method,
The predetermined timing is a predetermined reception frame by time division duplex.
A mobile communication system. The mobile communication system according to claim 1, wherein
The interference channel information transmitting means transmits the interference channel information including base station identification information for identifying a base station apparatus as a transmission destination,
The base station device that has received the interference channel information identifies whether or not the interference channel information is addressed to itself based on base station identification information included in the interference channel information.
A mobile communication system. The mobile communication system according to claim 4, wherein
Each of the base station devices
Immediately after transmitting the interference channel information addressed to the base station device, interference reduction performance information indicating the number of times the power of the interference signal related to the channel indicated by the interference channel information is reduced is stored for each of the adjacent base station devices. Further comprising an interference reduction performance information storage means,
The interference channel information transmitting means determines the transmission order to the base station apparatus that is the transmission destination of the interference channel information, based on the interference reduction performance information stored in the interference reduction performance information storage means.
A mobile communication system. The mobile communication system according to any one of claims 1 to 5,
Each base station apparatus performs radio communication with the terminal station apparatus by an orthogonal frequency division multiple access scheme and a time division multiple redundancy scheme,
A channel used for communication with the terminal station device is specified by a subcarrier frequency by orthogonal frequency division and a time slot by time division multiplexing.
A mobile communication system. A base station device that communicates with a terminal station device in its own cell,
An interference signal detecting means for detecting an interference signal that interferes with a channel used for communication with the terminal station device, based on a received signal;
Interference channel information transmitting means for sequentially transmitting the interference channel information indicating the channel of the interference signal to adjacent base station apparatuses until the power of the interference signal detected by the interference signal detecting means is reduced;
A base station apparatus comprising: A base station device that communicates with a terminal station device in its own cell,
Interference channel information receiving means for receiving interference channel information indicating a channel of an interference signal that interferes with communication of the other base station device from another base station device;
Channel assignment means for changing the assignment of the channel when the interference channel information received by the interference channel information receiving means is addressed to the own station and the channel indicated by the interference channel information is used;
A base station apparatus comprising: A control method of a base station apparatus that communicates with a terminal station apparatus in its own cell,
An interference signal detection step of detecting an interference signal that interferes with a channel used for communication with the terminal station device based on a received signal;
An interference channel information transmission step of sequentially transmitting interference channel information indicating a channel of the interference signal to adjacent base station apparatuses until the power of the interference signal detected in the interference signal detection step is reduced;
A control method for a base station apparatus. A control method of a base station apparatus that communicates with a terminal station apparatus in its own cell,
An interference channel information receiving step of receiving interference channel information indicating a channel of an interference signal that interferes with communication of the other base station device from another base station device;
A channel allocation step for changing the channel allocation when the interference channel information received in the interference channel information reception step is addressed to the own station and the channel indicated by the interference channel information is used;
A control method for a base station apparatus.

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