JP6335127B2 - COMMUNICATION CONTROL METHOD, COMMUNICATION CONTROL DEVICE, AND COMMUNICATION DEVICE - Google Patents

Description

  The present invention relates to a communication control method, a communication control device, and a communication device.

There is known a radio communication system that performs communication by performing signal multiplexing by TDMA (Time Division Multiple Access). Such a wireless communication system is often composed of a control station, a base station (fixed station), and a terminal (mobile station).
For example, the control station and the base station transmit and receive control messages via wired or wireless communication. Also, the control station and the terminal perform control message transmission / reception through direct wireless communication or indirect wireless communication via the base station.

The control station controls the transmission of the transmitter included in the base station or terminal by notifying the transmission permission time to the base station or terminal, for example, by a control message.
Generally, when signals output as radio waves collide with each other, signals cannot be received normally. Therefore, the control station controls transmission of the transmitter so that collision (interference) between signals does not occur at the receiver.

On the other hand, techniques for compensating for interference have been proposed. As an example, a configuration is known in which communication can be performed by extracting a desired signal by removing an interference wave received by a receiver using a blind adaptive array antenna technique (see, for example, Patent Document 1). .
The removal of interference waves by the blind adaptive array antenna technology is generally used to remove interference waves received from other systems. In the blind adaptive array antenna technology, the number of interference waves that can be removed may be limited depending on the hardware configuration. Specifically, the upper limit of the number of interference waves that can be removed simultaneously by blind-type adaptive array antenna technology is determined by the number of antennas, and the upper limit of the number of interference waves that can be removed by one less than the number of antennas. It becomes.

Maruta, Masuno, Nakato, Sugiyama, “Blind interference suppression using eigenvector beamspace CMA adaptive array with subcarrier transmission power control” IEICE Tech. Report, March 2014, vol 113, no. 456, RCS2013-343 , Pp. 223-228

  The number of interference waves received from other systems varies depending on the environment. For this reason, depending on the environmental conditions, there may be a surplus in the number of interference waves that can be removed by the receiver having the interference compensation function using the blind type adaptive array antenna technique as described above. The state in which there is a remainder in the number of interference waves that can be removed is a state in which the number of interference waves is smaller than the upper limit of the number of interference waves that can be removed by the receiver.

Communication efficiency can be improved by performing user multiplexing in which the surplus of the removable number of interference waves generated as described above is assigned to the communication of a plurality of users. However, as described above, the number of interference waves that can be removed has an upper limit. For this reason, if user multiplexing is performed in a state where the upper limit of the number of interference waves that can be removed is exceeded, interference waves that cannot be removed exist, and the communication state in the communication system becomes unstable.
In addition, when performing communication allocation as described above, depending on the state of interference received by the receiver that is the destination of the transmitter, there is a possibility that a transmitter that easily obtains a transmission opportunity and a transmitter that hardly obtains a transmission opportunity may occur. There is. If the difference in transmission opportunity between such transmitters is large, the service quality experienced by the user may be significantly reduced, for example, the user experience may be reduced.

  In view of the above circumstances, the present invention ensures communication stability and equalizes the transmission opportunities of each transmitter when controlling the transmitter so that a surplus of the number of interference waves that can be removed at the receiver is allocated to user multiplexing. It aims at realizing.

  One aspect of the present invention is a communication control method in a communication system including a communication control device, a plurality of transmitters and a plurality of receivers that perform wireless communication, and the receiver detects the number of interference waves received by the receiver. An interference wave number detection step, an interference wave number acquisition step in which the communication control device acquires interference wave numbers detected by the plurality of receivers, and an interference relationship between the communication control device in the transmitter and the receiver. Interference relation information acquisition step for acquiring interference relation information indicating the interference wave number acquired by the interference wave number acquisition step in order from the transmitter with the least number of past transmission opportunities, and the interference relation information acquisition. A transmission permission / inhibition determination step for determining whether to permit transmission for each transmitter based on the interference relation information acquired in the step. It is a communication control method.

  One aspect of the present invention is the communication control method described above, wherein the transmission permission / inhibition determining step is performed when the transmitter to be determined performs transmission based on the interference wave number and the interference relationship. The number of remaining removable interference waves, which is the remaining number of interference waves that can be removed, is calculated, and transmission is permitted when the minimum value of the calculated remaining number of remaining interference waves is greater than or equal to a predetermined value. When the minimum value is smaller than the predetermined value, it is determined that transmission should not be permitted.

  One aspect of the present invention is the communication control method described above, wherein the transmission permission determination step should allow transmission when a minimum value of the calculated remaining number of removable interference waves is zero or more. If the minimum value is smaller than zero, it is determined that transmission should not be permitted.

  One aspect of the present invention is the above-described communication control method, wherein the transmission availability determination step is performed when a minimum value of the calculated remaining number of removable interference waves is equal to or greater than a predetermined margin value greater than zero. It is determined that transmission should be permitted, and it is determined that transmission should not be permitted if the minimum value is smaller than the margin value.

  One aspect of the present invention is the communication control method described above, wherein the transmission propriety determination step determines that transmission should not be permitted after performing transmission propriety determination for all determination target transmitters. A predetermined number of transmitters in the lower order in which the transmission permission / inhibition determination is performed are excluded from the determination targets for the next transmission permission / inhibition determination.

  One aspect of the present invention is a communication control apparatus in a communication system including a plurality of transmitters and a plurality of receivers that perform wireless communication, and acquires interference wave numbers that are detected by the plurality of receivers. Interference wave number acquired by the interference wave number acquiring unit, in order from an interference relationship information acquiring unit that acquires interference relationship information indicating an interference relationship in the transmitter and the receiver, and a transmitter having a small number of past transmission opportunities. And a transmission permission / inhibition determination unit that determines whether or not transmission should be permitted for each transmitter based on the interference relationship information acquired by the interference relationship information acquisition unit.

  One aspect of the present invention is a communication apparatus that includes a receiver and a transmitter and is included in a communication system, and detects interference wave number received by the receiver from another communication system different from the communication system. And an interference wave number notification unit that is included in the communication system and that notifies the communication control device that controls transmission of the transmitter of the interference wave number detected by the interference wave number detection unit. .

  According to the present invention, when controlling a transmitter so as to allocate a surplus of the number of interference waves that can be removed by a receiver to user multiplexing, it is possible to ensure communication stability and equalize transmission opportunities of each transmitter. An effect is obtained.

It is a figure which shows the example of a whole structure of the communication system in 1st Embodiment. It is a figure which shows the structural example of the base station in 1st Embodiment. It is a figure which shows the structural example of the terminal device in 1st Embodiment. It is a figure which shows the structural example of the control station in 1st Embodiment. It is a figure which shows typically the example of the content of the interference related information in 1st Embodiment. It is a figure which shows typically the example of the content of the interference wave number information in 1st Embodiment. It is a figure which shows the example of the content of the removable maximum interference wave number information in 1st Embodiment. The example of the process sequence which the control station in 1st Embodiment performs is shown. It is a figure which shows the example of a process sequence which the control station in 1st Embodiment performs for the transmission permission determination in FIG. 8, transmitter control, and transmission history information update. It is a figure which shows the example of a process sequence which the control station in 2nd Embodiment performs for transmission propriety determination in FIG. 8, transmitter control, and transmission history information update. It is a figure which shows the example of a process sequence which the control station in 3rd Embodiment performs for transmission propriety determination in FIG. 8, transmitter control, and transmission history information update. It is a figure which shows the example of a process sequence which the control station in a modification performs for the transmission permission determination in FIG. 8, transmitter control, and transmission history information update.

<First Embodiment>
[Configuration example of communication system]
FIG. 1 shows an example of the overall configuration of a communication system in the present embodiment. As shown in the figure, the communication system in this embodiment includes a base station 100 (an example of a communication device), terminal devices 200-1, 200-2, 200-3 (an example of a communication device), and a control station 300. (An example of a communication control device).
The base station 100 and the control station 300 are fixed stations, and the terminal devices 200-1, 200-2, and 200-3 are mobile stations.

In the following description, the terminal devices 200-1, 200-2, and 200-3 will be referred to as the terminal device 200 unless otherwise distinguished. In the figure, an example in which three terminal devices 200-1, 200-2, and 200-3 are provided in the communication system is shown, but the number of terminal devices 200 provided in the communication system is not particularly limited.
In addition, although one base station 100 is shown in the figure, a plurality of base stations 100 may be provided in the communication system.

The base station 100 and the control station 300 communicate with each other by transmitting and receiving light or electrical signals by wired connection. In addition, the terminal device 200 and the control station 300 perform wireless communication via the base station 100.
Note that the terminal device 200 and the control station 300 may directly perform wireless communication without using the base station 100. However, in the following description, a case where the terminal device 200 and the control station 300 perform wireless communication via the base station 100 is taken as an example.
Moreover, the case where TDMA (Time Division Multiple Access) is applied to radio | wireless communication between the terminal device 200 and the control station 300 is mentioned as an example.
However, the wireless communication method applied in the present embodiment is not limited to TDMA, and may be, for example, another time division multiple access method. Moreover, this embodiment is applicable also to the system of the wireless communication by frequency division multiple access, for example.

The base station 100 includes a transmitter 101 and a receiver 102. The transmitter 101 performs transmission under wireless communication. The receiver 102 performs reception under wireless communication.
“T00” is assigned to the transmitter 101 as a transmitter ID that uniquely indicates the transmitter in the communication system. “R00” is assigned to the receiver 102 as a receiver ID that uniquely indicates the receiver in the communication system.

The terminal device 200-1 includes a transmitter 201-1 and a receiver 202-1. The transmitter 101 performs transmission under wireless communication. The receiver 102 performs reception under wireless communication.
The transmitter 201-1 is assigned “T01” as the transmitter ID. The receiver 202-1 is given “R01” as the receiver ID.

Similarly, the terminal device 200-2 includes a transmitter 201-2 and a receiver 202-2. The transmitter 201-2 is assigned “T02” as the transmitter ID, and the receiver 202-2 is assigned “R02” as the receiver ID.
The terminal device 200-3 includes a transmitter 201-3 and a receiver 202-3. The transmitter 201-3 is assigned “T03” as the transmitter ID, and the receiver 202-3 is assigned “R03” as the receiver ID.

Hereinafter, the transmitters 201-1, 201-2, and 201-3 are referred to as the transmitter 201 unless otherwise distinguished. The receivers 202-1, 202-2, and 202-3 are referred to as receivers 202 when not particularly distinguished.
Further, when there is no particular distinction between the transmitter 101 of the base station 100 and the transmitter 201 of the terminal device 200, they are simply referred to as a transmitter. Further, when there is no particular distinction between the receiver 102 of the base station 100 and the receiver 202 of the terminal device 200, they are simply referred to as a receiver.

[Example of base station configuration]
FIG. 2 shows a configuration example of the base station 100. The transmitter 101 in the base station 100 shown in the figure includes an external communication interface 111 and a signal transmission unit 112.
The external communication interface 111 receives a signal transmitted from the control station 300 by, for example, wired communication using an optical or electric signal.
The signal transmission unit 112 performs processing for transmitting a signal to the terminal device 200 through wireless communication. The signal transmission unit 112 includes a signal storage unit 1121 and a transmission control unit 1122.
The signal storage unit 1121 stores (buffers) a signal to be transmitted to the terminal device 200. The transmission control unit 1122 controls transmission of signals stored in the signal storage unit 1121.

Also, in the base station 100 of the figure, the receiver 102 includes an external communication interface 121, a signal receiving unit 122, and an interference wave number notification unit 123.
The external communication interface 121 transmits a signal to the control station 300 by, for example, wired communication using an optical or electric signal.
The signal receiving unit 122 performs a process of receiving a signal transmitted from the terminal device 200 through wireless communication. The signal reception unit 122 includes an interference compensation unit 1221.
The interference compensation unit 1221 compensates for radio wave interference received by the receiver 102 from another communication system. Specifically, the interference compensator 1221 extracts a desired signal by removing an interference wave received by the receiver 102 using a blind adaptive array antenna technique. Note that the configuration for the interference compensation unit 1221 to perform interference compensation is not limited to the blind-type adaptive array antenna technology, and other configurations for interference compensation may be employed.
In addition, the interference compensation unit 1221 includes an interference wave number detection unit 1222. The interference wave number detection unit 1222 detects the number of interference waves (interference wave number) received by the receiver 102 from another communication system (different system).

The interference wave number notification unit 123 notifies the control station 300 of the interference wave number detected by the interference wave number detection unit 1222.
Specifically, the interference wave number notification unit 123 generates an interference wave number notification message for notifying the interference wave number detected by the interference wave number detection unit 1222, and the generated interference wave number notification message is transmitted from the external communication interface 121 to the control station 300. To send to.

In addition, the signal receiving unit 122 receives a signal transmitted from the terminal device 200 by radio, and transfers the received signal to the control station 300 via the external communication interface 121.
Thus, the received signal received by the signal receiving unit 122 from the terminal device 200 and transferred to the control station 300 is at least one of the main signal and the interference wave number notification message transmitted from the terminal device 200 that is the transmission source of the received signal. including. The interference signal number notification message of the received signal indicates the interference signal number from another communication system detected by the receiver in the terminal device 200 that is the transmission source of the reception signal.

Further, the control station 300 transmits a base station transmission control message that is a control message for controlling transmission of signals by the transmitter 101. The transmitted base station transmission control message is received by the external communication interface 111 of the transmitter 101 and input to the transmission control unit 1122.
Transmission control section 1122 outputs a transmission trigger signal to signal storage section 1121 according to the transmission timing specified by the input base station transmission control message.

The signal accumulation unit 1121 transmits the accumulated signal to the destination terminal device 200 by wireless communication over a period specified by the transmission trigger signal.
The signal transmitted from the control station 300 and accumulated in the signal accumulating unit 1121 is a main message to be received by the destination terminal device 200 and a control message for designating the transmission timing of the transmitter 201 in the destination terminal device 200. Terminal transmission control message.

[Configuration example of terminal device]
A configuration example of the terminal device 200 will be described with reference to FIG. The transmitter 201 in the terminal device 200 in FIG. 1 includes an external communication interface 211 and a signal transmission unit 212.
The external communication interface 211 receives a main signal transmitted from the lower network 400 via wired or wireless communication.

The signal transmission unit 212 performs processing for signal transmission by wireless communication to the base station 100. The signal transmission unit 212 includes a signal accumulation unit 2121, a transmission control unit 2122, and an interference wave number notification unit 2123.
The signal accumulation unit 2121 accumulates transmission signals to be transmitted to the base station 100. Specifically, the signal storage unit 2121 stores a transmission signal including at least one of the main signal transferred from the external communication interface 211 and the interference wave number notification message generated by the interference wave number notification unit 2123.

The transmission control unit 2122 controls transmission of signals stored in the signal storage unit 2121.
The interference wave number notifying unit 2123 notifies the base station 100 of the interference wave number detected by the interference wave number detecting unit 2222 in the receiver 202. For this purpose, the interference wave number notification unit 2123 generates an interference wave number notification message for notifying the interference wave number detected by the interference wave number detection unit 2222, and causes the signal storage unit 2121 to store the generated interference wave number notification message.

The receiver 202 in the terminal device 200 of FIG.
The external communication interface 221 transmits the main signal output from the signal discriminating unit 2223 to the lower level network 400 via wired or wireless communication.

The signal receiving unit 222 executes processing related to reception of a signal transmitted from the base station 100. The signal reception unit 222 includes an interference compensation unit 2221 and a signal discrimination unit 2223.
The interference compensation unit 2221 performs compensation for radio wave interference received by the receiver 202 from another communication system. The interference compensation unit 2221 extracts a desired signal by removing the interference wave received by the receiver 102 from the signal of the received wave, for example, using a blind adaptive array antenna technique.

  Further, the interference compensation unit 2221 includes an interference wave number detection unit 2222. The interference wave number detection unit 2222 detects the number of interference waves (interference wave number) received by the receiver 102 from another communication system. The interference wave number detection unit 2222 outputs the detected interference wave number to the interference wave number notification unit 2123 in the signal transmission unit 212 of the transmitter 201.

The signal discriminating unit 2223 receives the signal received from the base station 100 via the interference compensation unit 2221 and discriminates the input signal. The signal received by the signal receiving unit 222 from the base station 100 includes at least one of a main signal and a transmission control message transmitted from the control station 300.
Therefore, the signal discriminating unit 2223 discriminates whether the signal received from the base station 100 is a main signal or a transmission control message.
The signal discriminating unit 2223 outputs the discriminated main signal to the external communication interface 221 when discriminating that the received signal is the main signal. As a result, the main signal is transmitted to the lower network 400.

On the other hand, if the signal discriminating unit 2223 discriminates that the received signal is a transmission control message, the signal discriminating unit 2223 outputs the discriminated transmission control message to the transmission control unit 2122 of the transmitter 201.
The transmission control unit 2122 outputs a transmission trigger signal to the signal storage unit 2121 according to the transmission timing specified by the transmission control message input from the signal discrimination unit 2223.

  The signal accumulation unit 2121 transmits the accumulated signal to the base station 100 by wireless communication over a period specified by the transmission trigger signal. As described above, the signal transmitted from the signal storage unit 2121 to the base station 100 includes the main signal and the interference wave number notification message generated by the interference wave number notification unit 2123, and is controlled by relaying the base station 100. Transferred to station 300.

[Configuration example of control station]
A configuration example of the control station 300 will be described with reference to FIG. The control station 300 in the figure includes a reception unit 301, a transmission allocation unit 302, a transmitter control unit 303, a storage unit 304, and a transmission unit 305.
The receiving unit 301 receives a signal transmitted from the base station 100 by radio.

The transmission allocation unit 302 performs transmission allocation for the transmitter 101 and the transmitter 201. The transmission allocation here is a process for determining how to allocate transmission resources to the transmitter 101 and the transmitter 201, respectively. The transmission resource allocation in the present embodiment is, for example, transmission time and slot allocation.
The transmission allocation unit 302 of this embodiment includes an interference wave number acquisition unit 321, an interference relationship information acquisition unit 322, a transmission availability determination unit 323, and a transmission history information update unit 324.

The interference wave number acquisition unit 321 acquires the interference wave number detected by each of the receiver 102 in the base station 100 and the receiver 202 in the terminal device 200.
The base station 100 transmits an interference wave number notification message indicating the interference wave number detected by the receiver 102 included in the base station 100 to the control station 300. In addition, the base station 100 relays the interference wave number notification message transmitted from each terminal apparatus 200 and transmits it to the control station 300. The interference wave number notification message transmitted from the terminal device 200 indicates the interference wave number detected by the receiver 202 in the terminal device 200.

The interference wave number acquisition unit 321 inputs the interference wave number notification message transmitted from the base station 100 from the reception unit 301 as described above. The interference wave number notification message includes a receiver ID indicating the corresponding receiver 102 or receiver 202. The interference wave number acquisition unit 321 acquires the interference wave number indicated by the input interference wave number notification message in association with the receiver ID included in the same interference wave number notification message.
The interference wave number acquisition unit 321 stores the interference wave number acquired in association with the receiver ID as described above in the interference state information stored in the interference state information storage unit 342 of the storage unit 304.

  The interference relationship information acquisition unit 322 acquires interference relationship information indicating the interference relationship between the transmitters 101 and 201 and the receivers 102 and 202. The interference relationship here refers to a relationship in which interference is caused when transmitters simultaneously transmit for each receiver.

The interference relationship can be specified based on the detection status of the radio wave transmitted from each transmitter in each receiver. The method for grasping the detection status of the radio wave transmitted from each transmitter in each receiver is not particularly limited, but as an example, the following method can be used in the present embodiment.
That is, a predetermined pilot signal is sequentially transmitted from each of the transmission devices, and each receiver detects whether or not the pilot signal is received. Thereby, the detection status of the radio wave transmitted from each transmitter is specified in each receiver.

In this case, the interference relationship information acquisition unit 322 instructs the base station 100 and each terminal device 200 to transmit predetermined pilot signals in an arbitrary order.
In response to the pilot signal transmission instruction, the transmitter control unit 303 generates a control message (pilot signal transmission request) instructing transmission of the pilot signal in accordance with the control of the interference relationship information acquisition unit 322, and the transmission unit 305. To the destination communication device (base station 100 or terminal device 200).

For example, a pilot signal transmission request transmitted to a certain destination communication device (base station 100 or terminal device 200) is received by the destination communication device.
When the destination communication apparatus is the base station 100, the transmitter 101 of the base station 100 transmits a pilot signal by broadcast or multicast to each terminal apparatus 200 in response to reception of the pilot signal transmission request.
When the destination communication apparatus is the terminal apparatus 200, the pilot signal transmission request is received by the receiver 202 of the terminal apparatus 200 through the base station 100, and the transmission control of the transmitter 201 is performed from the signal discriminating unit 2223. To the part 2122. When the pilot signal transmission request is transferred to the transmission control unit 2122, the transmitter 201 transmits a pilot signal to the base station 100 and each of the other terminal devices 200 by broadcast or multicast. Transmission of the pilot signal to the terminal device 200 is performed by relaying the base station 100.
As described above, the pilot signal transmitted from one communication device (base station 100 or terminal device 200) is not necessarily all other communication devices (base station 100 or terminal device 200) due to communication distances, radio wave conditions, and the like. ) May not be reached.

When the pilot signal can be received by the base station 100, the received pilot signal is received by the receiver 102. In response to receiving the pilot signal, the receiver 102 transmits a pilot signal reception response indicating that the pilot signal has been received to the control station 300.
In addition, when the pilot signal can be received by terminal apparatus 200, the received pilot signal is received by receiver 202. In response to receiving the pilot signal, the receiver 202 transmits a pilot signal reception response indicating that the pilot signal has been received, to the control station 300.

According to the above description, when base station 100 transmits a pilot signal transmission request with one communication device (base station 100 or terminal device 200) as a destination, the destination communication device transmits a pilot signal to another communication device. . Then, a pilot signal reception response is returned to the control station 300 from another communication apparatus that has received the pilot signal. The returned pilot signal reception response is input by the interference relation information acquisition unit 322 of the control station 300.
That is, the interference relationship information acquisition unit 322 in the control station 300 collects the return status of the pilot signal reception response obtained for each transmission of the pilot signal after sequentially transmitting the pilot signal for each communication device. Thereby, the interference relationship information acquisition unit 322 can specify the interference relationship between the transmitters 101 and 201 and the receivers 102 and 202 in the own communication system. The interference relationship information acquisition unit 322 generates interference relationship information indicating the identified interference relationship.

FIG. 5 schematically shows a content example of interference relationship information corresponding to an example of the interference relationship of the own communication system specified by the interference relationship information acquisition unit 322.
In the figure, the presence / absence of radio wave detection is shown for each combination of the transmitters 101 and 201 and the receivers 102 and 202. In the figure, each transmitter is indicated by a transmitter ID (FIG. 1), and each of the receivers 102 and 202 is indicated by a receiver ID (FIG. 1).
In the figure, “with radio wave detection” indicates that the radio wave transmitted from the corresponding transmitter is detected by the corresponding receiver. Specifically, under the above-described method using a pilot signal, “with radio wave detection” corresponds to a case where a pilot signal transmitted from a corresponding transmitter is received by a corresponding receiver. Therefore, the receiver corresponding to “with radio wave detection” in this case transmits a pilot signal reception response corresponding to the pilot signal transmitted from the corresponding transmitter.
On the other hand, “no radio wave detection” indicates that the radio wave transmitted from the corresponding transmitter was not detected by the corresponding receiver. Specifically, under the above-described method using the pilot signal, “no radio wave detection” corresponds to a case where the pilot signal transmitted from the corresponding transmitter is not received by the corresponding receiver. Therefore, the receiver corresponding to “no radio wave detection” in this case does not transmit a pilot signal reception response corresponding to the pilot signal transmitted from the corresponding transmitter.

According to the figure, the receiver 102 (receiver ID = R00) includes a transmitter 101 (transmitter ID = T00), a transmitter 201-1 (transmitter ID = T01), and a transmitter 201-2 (transmitter). ID = T02) and transmitter 201-3 (transmitter ID = T03) indicate that radio waves transmitted from each transmitter can be detected.
That is, in the case of the receiver 102 in the same figure, when transmission is simultaneously performed from two or more of the transmitter 101 and the transmitters 101, 201-1, 201-2, and 202-3, radio wave interference occurs. Have an interference relationship.

Next, the receiver 202-1 (receiver ID = R01) can detect radio waves transmitted from the transmitter 101 (transmitter ID = T00) and the transmitter 201-1 (transmitter ID = T01). Although it is in the situation, it is indicated that the radio waves transmitted from the transmitter 201-2 (transmitter ID = T02) and the transmitter 201-3 (transmitter ID = T03) cannot be detected.
In other words, the receiver 202-1 in the same figure has an interference relationship in which radio wave interference occurs when transmission is simultaneously performed from the transmitters 101 and 201-1.

Next, the receiver 202-2 (receiver ID = R02) includes the transmitter 101 (transmitter ID = T00), the transmitter 201-1 (transmitter ID = T01), and the transmitter 201-2 (transmitter ID). = T02), the radio waves transmitted from each of the transmitters 201-3 (transmitter ID = T03) cannot be detected.
In other words, the receiver 202-2 in the figure has an interference relationship in which radio wave interference occurs when two or more of the transmitters 101, 201-1 and 201-2 are simultaneously transmitted.

Next, the receiver 202-3 (receiver ID = R03) can detect radio waves transmitted from the transmitter 101 (transmitter ID = T00) and the transmitter 201-3 (transmitter ID = T03). Although it is in the situation, it is indicated that radio waves transmitted from the transmitter 201-1 (transmitter ID = T01) and the transmitter 201-2 (transmitter ID = T02) cannot be detected.
That is, it is shown that the receiver 202-3 in the same figure has an interference relationship in which radio wave interference occurs when transmission is simultaneously performed from the transmitters 101 and 201-3.

The interference relationship information acquisition unit 322 generates (acquires) interference relationship information indicating the specified interference relationship, for example, as shown in FIG. The data can be stored in the unit 342.
The interference relationship shown in the figure is an example. Further, the interference relationship changes depending on the radio wave condition, the position of the terminal device 200 that is a mobile station, and the like. Therefore, the interference relationship information acquisition unit 322 updates the interference relationship information by causing the communication system to execute an operation for specifying the interference relationship with the transmission of the pilot signal at predetermined time intervals, for example. .

Returning to FIG. In the transmission allocation unit 302, the transmission permission / inhibition determination unit 323 is acquired by the interference wave number acquisition unit 321 for the transmitters to be determined in the order of few past transmission opportunities based on the transmission history information indicating the transmission history for each transmitter. Whether or not transmission should be permitted is determined based on the interference wave number and the interference relationship specified by the interference relationship information acquisition unit 322.
Note that transmission history information used for derivation of transmission opportunities is stored in the transmission history information storage unit 341 of the storage unit 304.

The transmission history information update unit 324 updates the transmission history information stored in the transmission history information storage unit 341 in accordance with the result of transmission permission / inhibition determination by the transmission permission / inhibition determination unit 323.
The transmitter whose transmission is permitted by the transmission allocation unit 302 performs transmission according to a control message transmitted by a transmitter control unit 303 described later. That is, the fact that the transmission history information update unit 324 updates the transmission history information according to the result of the transmission permission / inhibition determination by the transmission permission / inhibition determination unit 323 means that the transmitter permitted to transmit has transmitted. This corresponds to updating the transmission history information.

The transmitter control unit 303 controls the transmission operation of the transmitter according to the determination result of the transmission permission determination unit 323.
Specifically, when the transmission permission / inhibition determination unit 323 determines that transmission should be permitted for a certain determination target transmitter, the transmitter control unit 303 controls the transmission (transmission permission message) indicating transmission permission. Is transmitted from the transmission unit 305 to the transmitter to be determined. In the transmission permission message, for example, a time allocated for transmission (transmission time) and a slot allocated for transmission (allocation slot) are shown. Note that the transmission permission / inhibition determination unit 323 may determine the transmission time and the allocation slot.
The transmitter to be determined performs transmission according to the transmission time and the assigned slot specified by the received transmission permission message.
On the other hand, if it is determined by the transmission permission determination unit 323 that transmission should not be permitted for the transmitter to be determined (transmission standby), the transmission permission message is not transmitted. As a result, the transmitter to be determined does not receive the transmission permission message, and therefore maintains the state waiting for transmission.
As described above, the transmitter control unit 303 causes the transmitter to perform transmission by transmitting the transmission permission message, and causes the transmitter to enter a standby state without performing transmission by not transmitting the transmission permission message. Can be controlled.

The storage unit 304 stores information used by the transmission allocation unit 302. The storage unit 304 shown in the figure includes a transmission history information storage unit 341 and an interference state information storage unit 342.
The transmission history information storage unit 341 stores transmission history information. The transmission history information includes a transmission time and the number of allocated slots in transmissions performed so far by each of the transmitters (transmitters 101 and 201).
As described above, the transmission time and the number of assigned slots are acquired based on the transmission time and the assigned slot determined for the transmitter that the transmission permission / inhibition determining unit 323 determines to allow transmission. Then, the acquired transmission time and the number of allocated slots are newly included in the transmission history information in association with the transmitter determined to be permitted to transmit by the transmission permission determination unit 323. In this way, the transmission history information is updated.

  The interference situation information storage unit 342 stores interference situation information. The interference state information is information formed including predetermined information indicating the state of radio wave interference in the communication system. For example, the interference state information includes interference wave number information indicating the interference wave number acquired by the interference wave number acquisition unit 321.

  FIG. 6 shows an example of the content of the interference wave number information. The interference wave information in the figure has a structure in which the number of interference waves is stored in association with the receiver ID corresponding to each receiver (receiver 102, 202). The interference wave number is based on the interference wave number notification message received by the control station 300, and indicates the number of interference waves received from another system detected by the receiver indicated by the corresponding receiver ID.

Further, the interference status information stored in the interference status information storage unit 342 includes maximum removable interference wave number information indicating the upper limit (removable maximum interference wave number) of the removable interference waves for each of the receivers 102 and 202.
FIG. 7 shows an example of the content of the maximum interference wave number information that can be removed. The removable maximum interference wave number information in the figure has a structure in which the maximum removable interference wave number is stored in association with the receiver ID corresponding to each of the receivers 102 and 202.
When the blind type adaptive array antenna technology is adopted as described above, the maximum number of interference waves that can be removed by one receiver is determined according to the number of antennas that the receiver uses for reception. Specifically, the maximum number of interference waves that can be removed is n−1 when the number of antennas is represented by n. That is, the maximum number of interference waves that can be removed is equal to the number obtained by subtracting 1 from the number of antennas that the receiver uses for reception.
The maximum removable interference wave number information may be stored in advance in the interference situation information storage unit 342 when the maximum removable interference wave number for each of the receivers 102 and 202 is known, for example.
Alternatively, each of the receivers 102 and 202 notifies the control station 300 of the maximum number of interference waves that can be removed at a predetermined timing. In addition, the control station 300 may store the maximum removable interference wave number information in the interference state information storage unit 342 using the notified maximum removable interference wave number.

[Example of processing procedure]
The flowchart of FIG. 8 shows an example of a processing procedure executed by the control station 300 in the communication system of the present embodiment.
The interference relationship information acquisition unit 322 in the control station 300 acquires interference information indicating the interference relationship in the own communication system (step S101). Therefore, the interference relationship information acquisition unit 322, for example, sequentially transmits pilot signals from the transmitters 101 and 201 as described above, and collects pilot signal reception responses returned from the receivers every time the pilot signals are transmitted. To do. Then, the interference relation information acquisition unit 322 identifies the interference relation from the collection result of the pilot signal reception response, and is included in the interference situation information stored in the interference situation information storage unit 342 based on the interference relation information indicating the identified interference relation. Updated interference relation information (illustrated in FIG. 5).
Moreover, when starting the process of step S101, the interference related information acquisition part 322 starts time measurement from the state which reset the interference condition update timer.

Next, the interference wave number acquisition unit 321 in the control station 300 acquires the interference wave number detected by each of the receiver 102 of the base station 100 and the receiver 202 of the terminal device 200 (step S102). The interference wave numbers detected by the receivers 102 and 202 are transmitted to the control station 300 as the interference wave number notification message as described above.
The interference wave number acquisition unit 321 updates the interference wave number information (illustrated in FIG. 6) included in the interference state information stored in the interference state information storage unit 342 based on the acquired interference wave number.

Next, the control station 300 performs transmission permission / inhibition determination, transmitter control, and transmission history information update processing (step S103).
The transmission permission / inhibition determination unit 323 performs the transmission permission / inhibition determination. The transmission permission / inhibition determination is a process in which the transmission permission / inhibition determination unit 323 sequentially determines whether or not transmission should be permitted for each of the transmitters 101 and 201.
The determination as to whether or not transmission should be permitted is made based on the interference status of the receivers 102 and 202 estimated when the transmitter to be determined performs transmission. The interference status of the receivers 102 and 202 is estimated using the interference relationship information updated corresponding to step S101 and the interference wave number information updated corresponding to step S102.
Further, the order of transmitters to be determined when determining whether or not to permit transmission is determined based on the transmission history information according to the order of few transmission opportunities so far. That is, the determination as to whether or not to permit transmission for each transmitter is performed in the order of giving priority to transmitters with few transmission opportunities.

Further, in the same step S103, the transmitter control unit 303 performs control such that a transmitter that is determined to be permitted to transmit by the transmission permission determination unit 323 performs transmission as transmitter control. Specifically, as described above, the transmitter control unit 303 transmits, for example, a transmission permission message indicating the transmission time and the allocation slot determined by the transmission permission determination unit 323 to the determination target transmitter.
Further, as transmitter control, the transmitter control unit 303 permits transmission when the transmission permission determination unit 323 determines that transmission should not be permitted (transmission should be waited) for the transmitter to be determined. Do not message. Thereby, it can be set as the state which waited for transmission about the transmitter of determination object.

In the same step S103, the transmission history information update unit 324 updates the transmission history information according to the determination result of the transmission permission / inhibition determination unit 323.
That is, as described above, the transmission history information update unit 324, when the transmission permission determination unit 323 determines that transmission should be permitted for the determination target transmitter, the transmission history of the determination target transmitter is transmitted to the transmission history. Update to include new information. As described above, the transmission history corresponding to one transmission from the transmitter includes the transmission time and the number of allocation slots (number of allocation slots) determined by the transmission permission determination unit 323 and included in the transmission permission message. .

The control station 300 determines whether or not the time (timer time) counted by the interference status update timer that has started timing in accordance with step S101 has expired (step S104). The determination in step S104 may be performed by the interference relationship information acquisition unit 322, for example.
If the timer time has not expired (step S104-NO), the processes of steps S102 and S103 are performed again. That is, the acquisition of the interference wave number in step S102, the transmission permission / inhibition determination, the transmitter control, and the update of transmission history information in step S103 are repeatedly executed as a loop process until the timer time expires.
Then, when the timer time expires (step S104-YES), the process is returned to step S101. As a result, the transmission permission / inhibition determination is performed after updating the interference relation information. As described above, the interference relationship in the communication system changes with the passage of time according to the position of the terminal device 200 that is a mobile station, the radio wave condition, and the like. Therefore, the transmission availability determination unit 323 appropriately determines the transmission availability according to the current state of the communication system by performing the transmission availability determination after updating the interference-related information every fixed time (timer time). It can be performed.

The flowchart in FIG. 9 illustrates an example of a processing procedure executed by the control station 300 for the determination of whether transmission is possible, the transmitter control, and the transmission history information update as step S103 in FIG.
First, the transmission permission / inhibition determination unit 323 substitutes an initial value “1” for a variable j indicating the number of times a transmitter to be determined is selected (step S201).

Next, the transmission permission / inhibition determination unit 323 selects the transmitter i as the jth determination target from the transmitters 101 and 201 (step S202). The process of step S202 can be expressed as a function according to the following equation 1.
S (j) = i (Expression 1)
Expression 1 indicates that the j-th determination target is the transmitter i. Note that i represents a number assigned to the transmitter. As an example, a transmitter ID can be used for the number i.

In the present embodiment, Equation 1 is a function that sorts the transmitters in ascending order of index values indicating transmission opportunities. Specifically, the following can be given as index values as transmission opportunities.
The index value indicating the transmission opportunity can be an integrated value for the transmission time when the transmitter has performed transmission so far. The transmission permission / inhibition determination unit 323 can acquire the transmission time when the transmitter performs transmission from the transmission history information stored in the transmission history information storage unit 341.
Further, the index value indicating the transmission opportunity can be a moving average value of the transmission time in the past up to a certain period.

The index value indicating the transmission opportunity can be an integrated value of the amount of data (transmission data amount) transmitted when the transmitter performs transmission. The transmission permission / inhibition determining unit 323 can determine the transmission data amount in one transmission based on, for example, the transmission time and the allocation slot in the transmission history information. That is, the amount of transmission data in one transmission is obtained by multiplying the amount of data that can be transmitted by the allocation slot and the transmission time.
The index value indicating the transmission opportunity can be a moving average value of the amount of transmission data in the past up to a certain period.

Next, when it is assumed that the transmitter i has performed transmission, the transmission permission / inhibition determining unit 323 calculates the removable interference wave remaining number N ^a _x of the receiver x to which the transmitter i causes interference (step S203). .
As a specific example, the receiver x when the transmitter i is the transmitter 201-1 (transmitter ID = T01) under the interference relationship illustrated in FIG. Receiving receiver 102 (receiver ID = R00), receiver 202-1 (receiver ID = R01), and receiver 202-2 (receiver ID = R02).
Further, the removable interference wave remaining number N ^a _x is the remaining number of interference waves that can be removed by the corresponding receiver x.

Then, in step S203, the transmission permission / inhibition determination unit 323 calculates ^a removable interference wave remaining number N ^a _{x according} to the following Expression 2.
N ^a _x = N ^a _x −1 (Formula 2)
That is, when the transmitter i transmits, the radio wave of the transmitter i reaches the receiver x and increases the number of interference waves by one. Then, the receiver x removes the interference wave from the transmitter i. Therefore, the remaining interference wave remaining number N ^a _x of the receiver x is reduced by one according to Equation 2.

Here, the transmission determination unit 323, in the first step S203 in the loop process of steps S202～S212, removable interference remaining number ^N _a removable interference by utilizing the initial value of _x number of remaining ^N _{a x} Is calculated.
The initial value of the removable interference wave remaining number N ^a _x is obtained by subtracting the interference wave number detected by the receiver x from the maximum removable wave number of the corresponding receiver x. That is, the transmission permission / inhibition determination unit 323 can obtain the initial value of the removable interference wave remaining number N ^a _x by using the maximum removable interference wave number information and the interference wave number information stored in the interference state information storage unit 342. .

Further, when it is assumed that the transmitter i has performed transmission, the transmission permission / inhibition determining unit 323 calculates the number of remaining interference waves N ^a _y of the receiver y destined for the transmitter i (step S204).
Here, the receiver y that is the destination of the transmitter i is one of the receivers x for which the remaining interference wave remaining number N ^a _x has been calculated in step S203.
The signal transmitted from the transmitter i for the receiver y is a desired signal and does not need to be removed as an interference wave. However, in step S203, the remaining interference wave remaining number is also subtracted for the receiver y. Therefore, in step S204, the transmission permission / inhibition determination unit 323 calculates the remaining interference wave remaining number N ^a _y of the receiver y by the following equation 3.
N ^a _y = N ^a _x +1 (Formula 3)
That is, according to Equation 3, the remaining number of removable interference waves N ^a _y is obtained by returning the remaining number of removable interference waves N ^a _x subtracted in step S203 to the value before the subtraction.

Next, the transmission permission / inhibition determining unit 323 determines whether or not the minimum value min (N ^a ) of the remaining number of removable interference waves N ^a for each receiver is equal to or greater than “0” (zero). (Step S205).
When it is determined that the minimum value min (N ^a ) is equal to or greater than “0” (step S205—YES), each receiver in the communication system removes the interference wave even if the transmitter i performs transmission. The desired signal can be properly received.
Therefore, the transmission permission / inhibition determining unit 323 in this case determines that the transmission of the transmitter i should be permitted (step S206).

In response to the determination in step S206, the transmitter control unit 303 transmits a transmission permission message to the transmitter i (step S207). As described above, the transmission permission message includes information specifying the transmission time and the allocation slot determined by the transmission permission determination unit 323 corresponding to the transmitter that is determined to be permitted to transmit.
In addition, the transmission history information update unit 324 updates the transmission history information according to the determination in step S206 (step S208). Specifically, the transmission history information updating unit 324 determines the transmission time and the number of allocated slots (number of allocated slots) determined by the transmission permission / inhibition determining unit 323 corresponding to the transmitter permitted to transmit as the transmitter i. The associated transmission history information is newly stored in the transmission history information storage unit 341. Thereby, the result of transmission performed by the transmitter i in response to the transmission permission message transmitted in step S207 is reflected in the transmission history information.

On the other hand, if it is determined that the minimum value min (N ^a ) is less than “0” (step S205—NO), the transmitter i may perform transmission to cause more interference waves than the maximum removable interference wave number. There will be a receiver that receives the signal. That is, there are receivers that cannot properly receive a desired signal in the communication system.
Therefore, in this case, the transmission permission / inhibition determination unit 323 determines that the transmission of the transmitter i should be waited (step S209).
If it is determined in step S209 that the transmission of the transmitter i should be waited for, the processes in steps S207 and S208 are skipped. As a result, the transmitter i maintains a state of waiting for transmission because it does not receive the transmission permission message. Also, transmission history information for the transmitter i is not updated.
If it is determined in step S209 that transmission from the transmitter i should be waited, transmission by the transmitter i is not performed. Here, the remaining removable interference wave number N ^a _x for each receiver x calculated in the previous step S203 is a value when it is assumed that the transmitter i performs transmission. For this reason, if it is determined in step S209 that transmission from the transmitter i should be waited and the transmitter i does not perform transmission, the remaining interference wave remaining number N ^a _x is calculated in step S203. It is necessary to set it back to the value before being used.
Assuming that that executes the loop processing of the subsequent steps S202~S212 without returning the value of removable interference remaining number N ^a _x, errors in removable interference remaining number N ^a _x calculated in step S203 As a result, an error also occurs with respect to the remaining interference wave remaining number N ^a _y of the receiver y. As a result, an error also occurs in the transmission feasibility determination in step 205.
Therefore, when it is determined in step S209 that the transmission of the transmitter i should be waited, the transmission availability determination unit 323 returns the remaining interference wave remaining number N ^a _x to the value before the calculation in step S203 ( Step S210). For this purpose, the transmission permission / inhibition determination unit 323 may perform, for example, decrementing (N ^a _x = N ^a _x −1) for the current removable interference wave remaining number N ^a _x .

When the process of step S208 or the process of step S210 ends, the transmission permission / inhibition determination unit 323 increments the variable j (step S211).
Next, the transmission permission / inhibition determination unit 323 determines whether or not the variable j incremented in step S211 is larger than the total number N of transmitters (step S212). Specifically, the total number N of transmitters is “4” under the configuration of the communication system of this embodiment shown in FIG.

  When it is determined that the variable j is equal to or less than the total number N of transmitters (step S212—NO), there are still transmitters that are not yet subject to transmission determination. Therefore, the transmission permission / inhibition determining unit 323 in this case returns the process to step S202. As a result, it is determined whether or not transmission is possible, with a transmitter having the smallest index value indicating a transmission opportunity among the transmitters that are not determined as transmission possible.

  When the determination of whether transmission is possible for all transmitters is completed, it is determined that the variable j is larger than the total number N of transmitters (step S212—YES), and the processing as step S103 in FIG. 8 ends.

As described above, the control station 300 according to the present embodiment determines whether or not transmission is possible for each transmitter, determines that the transmitter that is determined to permit transmission is to perform transmission, and waits for transmission. The assigned transmitter is assigned transmission so as to wait for transmission.
Here, the transmission permission / inhibition determination uses the interference relationship between the transmitter and the receiver in the own communication system and the number of interference waves detected by the receiver. As a result, in the communication system of the present embodiment, the surplus of the removable number of interference waves is used for transmitter transmission (user multiplexing) while preventing the number of interference waves received by each receiver from exceeding the maximum number of removable interference waves. It becomes possible to do.
In this embodiment, when performing transmission assignment as described above, transmission resources are preferentially assigned from transmitters with few transmission opportunities based on transmission history information. Can be equalized. In this way, in the present embodiment, it is possible to increase resource use efficiency in the communication system.

Second Embodiment
Next, the second embodiment will be described. In the present embodiment, the overall configuration of the communication system may be the same as in FIG. In addition, the configurations of the base station 100, the terminal device 200, and the control station 300 in the present embodiment may be the same as those in FIGS. 2, 3, and 4, respectively.
Further, the flow of processing executed by the control station 300 may be the same as the flowchart of FIG.

  The flowchart of FIG. 10 shows an example of a processing procedure executed by the control station 300 for the transmission permission / inhibition determination, transmitter control, and transmission history information update as step S103 of FIG. 8 in the present embodiment. In the figure, steps that are the same as those in FIG. 9 are denoted by the same reference numerals, description thereof is omitted, and differences from FIG. 9 are mainly described.

In the process of FIG. 10, the process of step S205A is executed instead of step S205 of FIG.
In step S205A, the transmission permission / inhibition determining unit 323 determines whether or not the minimum value min (N ^a ) of the remaining number of removable interference waves N ^a for each receiver is equal to or greater than a predetermined margin value M. . Here, the margin value M is a value larger than “0” (zero). That is, the margin value M is a natural number of 1 or more.
If the minimum value min (N ^a ) is equal to or greater than the margin value M, the transmission permission / inhibition determination unit 323 determines that transmission should be permitted for the transmitter i (step S206). On the other hand, if it is determined in step S205A that the minimum value min (N ^a ) is less than the margin value M, the transmission permission / inhibition determination unit 323 determines that the transmitter i should wait for transmission (step S209).

According to the processing shown in the figure, transmission allocation of transmitters is performed in a state where a margin is given to the number of remaining interference waves that can be removed.
The number of interference waves received by a receiver from another communication system and the interference relationship in the local communication system vary depending on, for example, the radio wave condition or the change in the position of the terminal device 200 that is a mobile station.
For this reason, there is a possibility that the minimum value min (N ^a ) based on the processing of step S203 and step S204 is different from the actual value when the processing of step S205A is being executed. For example, when the actual value is smaller than the minimum value min (N ^a ) based on the processes in steps S203 and S204, it may be determined that the transmission of the transmitter i should be permitted. . In this case, when the transmitter i performs transmission, a receiver that actually receives an interference wave larger than the maximum number of interference waves that can be removed and cannot completely remove the interference wave is generated. May be a factor that hinders proper communication.

Therefore, in the present embodiment, as in step S205A, the minimum value min (N ^a ) based on the processing in steps S203 and S204 is compared with the margin value to determine whether transmission is possible.
Thereby, even when it is determined that the transmission of the transmitter i should be permitted in a state where the actual value is smaller than the minimum value min (N ^a ), the interference wave can be completely removed. It is possible to reduce the likelihood that no receiver will occur. That is, according to the present embodiment, it is possible to improve the follow-up performance with respect to the interference relationship in the own communication system and the change in interference received from another communication system with respect to the stabilization of the communication in the communication system.

<Third Embodiment>
Subsequently, the third embodiment will be described. In the present embodiment, the overall configuration of the communication system may be the same as in FIG. In addition, the configurations of the base station 100, the terminal device 200, and the control station 300 in the present embodiment may be the same as those in FIGS. 2, 3, and 4, respectively.
Further, the flow of processing executed by the control station 300 may be the same as the flowchart of FIG.

  The flowchart in FIG. 11 illustrates an example of a processing procedure executed by the control station 300 for the transmission permission / inhibition determination, transmitter control, and transmission history information update as step S103 in FIG. 8 in the present embodiment. In the figure, steps that are the same as those in FIG. 10 are denoted by the same reference numerals, description thereof is omitted, and differences from FIG. 10 are mainly described.

  In FIG. 11, the loop process in steps S202 to S212 is set as a transmission permission / inhibition determination loop process RP1. In the present embodiment, the process in step S205A in the transmission permission / inhibition determination loop process RP1 may be replaced with the process in step S205 in FIG.

In FIG. 11, when the transmission permission / inhibition determination loop process RP1 ends, the transmission permission / inhibition determination unit 323 determines whether or not there is a transmitter that is determined to wait for transmission in the transmission permission / inhibition determination loop process RP1 (step S213). ).
When it is determined that there is a transmitter that is determined to be waiting for transmission (step S213-YES), the transmission permission / inhibition determination unit 323 is a determination target among the transmitters that are determined to be waiting for transmission. The transmitter having the lowest selection order is excluded from the determination targets (step S214). When the process of step S214 is completed, the transmission permission / inhibition determining unit 323 ends the process illustrated in FIG.
On the other hand, when it is determined that there is no transmitter that is determined to be waiting for transmission (NO in step S213), step S214 is skipped, and the process illustrated in FIG.

After the transmitter is excluded from the determination target in the process of step S214, when the process of FIG. 8 ends, it is determined whether or not the timer time has expired by the next step S104 of FIG. If has not expired, the process of the next step S103, that is, the process of the next FIG. 11 is executed.
In the process of FIG. 11 executed again, in step S202, the transmitter i to be determined is selected from transmitters that do not include the transmitter excluded from the target of determination in the previous step S214.
Further, in the process of FIG. 11 executed again, in step S203, the receiver which is excluded from the determination target by the process of the previous step S214 is excluded and the receiver x can be removed for each receiver x. The remaining interference wave number N ^a _x is calculated.

The transmitter excluded from the determination target by the process of step S214 is a transmitter that has the highest transmission opportunity in the past among transmitters that cause a receiver that cannot completely remove interference waves by performing transmission. . For such a transmitter, even if transmission is not permitted for a certain period thereafter, it does not hinder the equalization of transmission opportunities, and in consideration of the stability of communication in the communication system, it is in a transmission standby state. It is preferable to be.
Therefore, the transmission permission / inhibition determination unit 323 according to the present embodiment performs the transmission permission / inhibition determination on all the determination target transmitters by the processing in step S213 and step S214, and then determines that the transmission should not be permitted. Among the transmitters, the transmitter with the lowest order in which transmission is determined is excluded from the determination targets for the next transmission determination. For transmitters excluded from the determination target, transmission is not reliably performed in the next transmission permission / inhibition determination.
As a result, it becomes possible to give a margin to the number of residual interference waves that can be removed at the receiver without hindering equalization of transmission opportunities of the transmitter in the communication system. For example, the number of users that can be multiplexed by user multiplexing is reduced. It becomes possible to increase.
In step S214, one transmitter having the lowest order in which transmission is determined among transmitters determined not to be permitted to be transmitted is excluded from the determination targets for the next transmission determination. ing. However, in step S214, the transmission permission / inhibition determination unit 323 may exclude, for example, a predetermined number of transmitters in the lower order in which transmission permission / inhibition determination has been performed, from the determination target of the next transmission permission / inhibition determination.

<Modification>
Then, the modification of this embodiment is demonstrated. The flowchart in FIG. 12 illustrates an example of a processing procedure executed by the control station 300 for the transmission permission / inhibition determination, transmitter control, and transmission history information update as step S103 in FIG. 8 in the modification. In the figure, steps that are the same as those in FIG. 11 are denoted by the same reference numerals and description thereof is omitted.
In the figure, when the transmission permission / inhibition determining unit 323 excludes the transmitter having the lowest selection order as the determination target from the transmitters determined to be waiting for transmission in step S214, the process proceeds to step S201. Return processing.
In other words, in the modified example, as the process of step S103 in FIG. 8, the loop process RP2 in steps S201 to S214 is repeatedly executed until it is determined that there is no transmitter determined to wait for transmission in step S213. The
Such processing can also provide a margin for the number of remaining removable interference waves in the receiver without hindering equalization of transmission opportunities of the transmitter in the communication system.

  In addition, you may make it implement | achieve the base station 100, the terminal device 200, the control station 300, etc. in embodiment mentioned above with a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory of a computer unit serving as a server or a client in that case may be included that holds a program for a certain period of time. Further, the program may be a program for realizing a part of the above-described functions, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system. You may implement | achieve using programmable logic devices, such as FPGA (Field Programmable Gate Array).

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Base station, 101 ... Transmitter, 102 ... Receiver, 111 ... External communication interface, 112 ... Signal transmission part, 121 ... External communication interface, 122 ... Signal reception part, 123 ... Interference wave number notification part, 200-1, 200-2, 200-3 ... Terminal device, 201-1, 201-2, 201-3 ... Transmitter, 202-1, 202-2, 202-3 ... Receiver, 211 ... External communication interface, 212 ... Signal Transmission unit, 221 ... external communication interface, 222 ... signal reception unit, 300 ... control station, 301 ... reception unit, 302 ... transmission allocation unit, 303 ... transmitter control unit, 304 ... storage unit, 305 ... transmission unit, 321 ... Interference wave number acquisition unit, 322 ... interference relation information acquisition unit, 323 ... transmission availability determination unit, 324 ... transmission history information update unit, 341 ... transmission history information storage unit, 342 Interference status information storage unit, 400 ... subordinate network, 1121 ... signal storage unit, 1122 ... transmission control unit, 1221 ... interference compensation unit, 1222 ... interference wave number detection unit, 2121 ... signal storage unit, 2122 ... transmission control unit, 2123 ... Interference wave number notification unit, 2221 ... interference compensation unit, 2222 ... interference wave number detection unit, 2223 ... signal discrimination unit

Claims (7)

A communication control method in a communication system comprising a communication control device, a plurality of transmitters and a plurality of receivers for performing wireless communication,
An interference wave number detecting step in which the receiver detects an interference wave number received by the receiver;
The communication control apparatus acquires an interference wave number detected by the plurality of receivers, an interference wave number acquisition step;
An interference relationship information acquisition step in which the communication control apparatus acquires interference relationship information indicating an interference relationship in the transmitter and the receiver;
Said communication control apparatus, in order from the past transmission opportunity is small transmitter, and the interference wave number obtained by the interference wave number acquisition step, on the basis of the acquired interference related information by the interference related information acquisition step, the transmission When the transmitter performs transmission, it calculates the remaining number of interference waves that can be removed for each of the receivers, and based on the remaining number of interference waves that can be removed , A communication control method comprising: a transmission permission / inhibition determining step for determining whether or not transmission should be permitted. A communication control method in a communication system comprising a communication control device, a plurality of transmitters and a plurality of receivers for performing wireless communication,
An interference wave number detecting step in which the receiver detects an interference wave number received by the receiver;
The communication control apparatus acquires an interference wave number detected by the plurality of receivers, an interference wave number acquisition step;
An interference relationship information acquisition step in which the communication control apparatus acquires interference relationship information indicating an interference relationship in the transmitter and the receiver;
Said communication control apparatus, in order from the past transmission opportunity is small transmitter, and the interference wave number obtained by the interference wave number acquisition step, on the basis of the acquired interference related information by the interference related information acquisition step, the transmission machine calculates the removable interference remaining number is the number of remaining removable interference wave number for each of the receiver when performing transmission, the minimum value of said removable interference remaining number predetermined value determines that it should allow the transmission to the transmitter if it is more, the transmission determination that said minimum value is carried out for determining transmission availability determination that it should not allow the transmission to the transmitter when the smaller than a predetermined value Step and
A communication control method. Wherein in the transmission determination step,
Said minimum value is determined to be allowed to transmit if it is greater than zero, the communication control method according to claim 2 determines that the minimum value should not be allowed to transmit is smaller than zero. Wherein in the transmission determination step,
The determination is made that transmission should be permitted when the minimum value is greater than or equal to a predetermined margin value greater than zero, and it is determined that transmission should not be permitted when the minimum value is smaller than the margin value. Communication control method. Wherein in the transmission determination step,
After the transmission determination for all the determination target transmitter, the transmission availability order determination has been made a predetermined number of lower transmitter out of the determined transmitter and should not be allowed to transmit, The communication control method according to any one of claims 1 to 4, wherein the communication control method is excluded from a determination target for a next transmission determination. A communication control apparatus in a communication system including a plurality of transmitters and a plurality of receivers for performing wireless communication,
An interference wave number acquisition unit for acquiring interference wave numbers detected by the plurality of receivers;
An interference relationship information acquisition unit for acquiring interference relationship information indicating an interference relationship in the transmitter and the receiver;
Based on the interference wave number acquired by the interference wave number acquisition unit and the interference relationship information acquired by the interference relationship information acquisition unit in order from the transmitter with the least number of transmission opportunities in the past, the transmitter performed transmission. If the calculated removable interference remaining number is the number of remaining removable interference wave number for each of said receiver based on said removable interference remaining number, whether or not to permit the transmission to the transmitter A communication control apparatus comprising: a transmission permission / inhibition determination unit that determines whether or not transmission is possible. Included in the communication system comprising a communication control device according to claim 6, comprising a communication device that Ru and a said transmitter and said receiver,
An interference wave number detection unit for detecting an interference wave number received by the receiver from another communication system different from the communication system;
A communication apparatus comprising: an interference wave number notification unit that notifies the communication control apparatus of the interference wave number detected by the interference wave number detection unit.

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