WO2016080260A1 - Communication system - Google Patents

Abstract

The present invention is provided with a first base station device, a second base station device, and a terminal device. The terminal device recognizes interference between transmission waves from the first base station device and transmission waves from the second base station device, and transmits a suppression instruction instructing the second base station device to suppress transmission. When receiving the suppression instruction from the terminal device, the second base station device suppresses transmissions to the terminal device.

Description

Communications system

The present invention relates to a communication system, and more particularly to a wireless communication system used in a mobile phone network.
This application claims priority based on Japanese Patent Application No. 2014-236507 filed in Japan on November 21, 2014, the contents of which are incorporated herein by reference.

In a wireless communication system, for example, LTE (Long Term Evolution), a frequency allocation method for each cell using the same frequency between adjacent cells is adopted in order to improve the use efficiency of frequency resources. In the vicinity of a cell boundary where interference between cells is large, in order to improve throughput, 3GPP (3rd Generation Partnership Project) Rel. 10 (Release 10) employs inter-cell interference coordination (ICIC). Also, Rel. 11 adopts e-ICIC (enhanced-ICIC), which is an extended ICIC system. On the other hand, in 3GPP, introduction of a communication service using LTE (Long Term Evolution) or LTE-Advanced (LTE-A) in an unlicensed band (hereinafter referred to as this communication service) is under consideration. . The unlicensed band is a frequency band that can be used without requiring authorization from the authorities. An unlicensed band is also called a license-free frequency band. On the other hand, the frequency band that can be used by the authorization by the authorities is called a licensed band or a frequency band that requires a license. For such communication services, 3GPP Rel. It will be discussed after 13th.

The above communication service can be realized by using a license-free band (for example, 5 GHz band, etc.) that is common throughout the world even for a communication carrier that does not have a license band. In addition, since this communication service uses a license-free band, it is expected to be provided free of charge or economically. For this reason, when a large number of users who desire a free or economical service access the wireless network nodes all at once, interference may occur and communication quality and communication speed may be reduced.
Therefore, in Patent Literature 1, a macro base station does not transmit or transmit in a heterogeneous mixed network (heterogeneous network) where a terminal device used by a user is a macro base station (macro cell) or a low power node (small cell). The first reception quality in the first transmission interval when the power is reduced and the second reception quality in the second transmission interval when the macro base station and the low power node transmit are measured and transmitted to the macro base station. When the station performs coordinated multipoint transmission, the station allocates the radio resources of the terminal device existing at the end of the coordinated area to the first transmission interval based on the first and second reception qualities, and reduces the degradation of characteristics due to interference and the throughput. It is described that the improvement is performed.

JP 2013-42342 A

However, in the above-described processing, the terminal device needs to acquire both the reception quality when the macro cell is not transmitted or the transmission power is reduced and the reception quality when the macro cell and the small cell transmit. Cost. Moreover, since a macro cell generally communicates with a plurality of user terminals, the time for processing a specific user terminal is limited. In addition, it takes time for the macro cell to determine a new resource allocation based on the reception quality information, and it also takes time for the determined allocation information to be transmitted from the macro cell to the small cell and the terminal device. For this reason, the conventional communication system has a problem that a highly urgent process in which a large delay (for example, several minutes) is not allowed cannot be performed. In addition, since a lot of time is required, in an environment where the reception quality frequently and dynamically fluctuates, there is a problem that reception quality cannot be acquired and correct information cannot be acquired.

In cooperative communication in heterogeneous networks, there is a problem that it takes time to reduce interference.

One aspect of the present invention is a communication system including a first base station apparatus, a second base station apparatus, and a terminal apparatus, wherein the terminal apparatus transmits a transmission wave from the first base station apparatus; An interference recognizing unit for recognizing interference with a transmission wave from the second base station device, and when the interference recognizing unit recognizes the interference, a suppression instruction for instructing suppression of transmission is transmitted to the second base station device An interference notification unit, and the second base station device is a communication system including an interference processing unit that suppresses transmission to the terminal device when receiving the suppression instruction from the terminal device.

According to the present invention, interference in a terminal device can be reduced in a short time in cooperative communication in a heterogeneous mixed network.

It is a key map showing an example of a communications system concerning a 1st embodiment. It is a block diagram which shows the structure of the base station apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the terminal device which concerns on 1st Embodiment. It is a sequence diagram which shows the example of inter-cell interference control. It is a sequence diagram which shows the communication process which concerns on 1st Embodiment. It is a conceptual diagram which shows an example of the communication system which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the base station apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the terminal device which concerns on 2nd this embodiment. It is a sequence diagram which shows the communication process which concerns on 2nd Embodiment. It is a conceptual diagram which shows the other example of the communication system which concerns on 2nd Embodiment. It is a conceptual diagram which shows an example of the communication system which concerns on 3rd Embodiment. It is a timing chart which shows an example of the communication situation of the communications system concerning a 3rd embodiment. It is a sequence diagram which shows the communication process which concerns on 3rd Embodiment. It is a timing chart which shows the other example of the communication condition of the communication system which concerns on 3rd Embodiment. It is a conceptual diagram which shows an example of the communication system which concerns on 4th Embodiment. It is a conceptual diagram which shows the process of the small cell which concerns on 4th Embodiment. It is a block diagram of the communication system which concerns on the modification of 4th Embodiment. It is a timing chart which shows an example of the communication condition of the communication system which concerns on the modification of 4th Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram illustrating an example of a communication system 1 according to the present embodiment.
The communication system 1 includes a small cell S-eNB, a macro cell M-eNB, and a terminal device UE. A small cell is a base station device having a small communicable range (for example, a radius of several hundred m or less) within which a radio wave to be transmitted reaches. Small cells are microcells with a radius of tens of meters to several hundreds of meters, picocells (also called nanocells) with a radius of tens of meters to tens of meters, and a number of radii of coverage It is a generic name for femtocells that are 10 cm to several meters. An ellipse surrounding the small cell S-eNB indicates the small cell area SC that is the communicable range. A macro cell is a base station apparatus that has a larger range (for example, a radius of several hundred m to several km) for transmitting radio waves than a small cell. An ellipse surrounding the macro cell M-eNB indicates the macro cell area MC that is the communicable range.

The small cell S-eNB is a base station device of the operator X that provides a license-free band. In the small cell area SC, a terminal device UE (User Equipment) can communicate using an unlicensed band. The macro cell M-eNB is a base station device of the operator Y that provides a license band.
In the macro cell area MC, the terminal apparatus UE can communicate using a licensed band. In the example shown in FIG. 1, since the terminal apparatus UE is located in an area where the small cell area SC and the macro cell area MC overlap, communication using both the license-unnecessary band and the license band is performed. Can transmit and receive data. When the terminal device UE performs communication using both of them, a transmission wave from the small cell S-eNB and a transmission wave from the macro cell M-eNB may interfere with each other. This is because the band and timing of the transmission wave are individually determined in the small cell S-eNB and the macro cell M-eNB, and the terminal apparatus UE is not involved in the determination.
Note that the operator Y who operates the macro cell M-eNB may install the small cell S-eNB in order to eliminate the insensitive area where the transmission wave from the macro cell M-eNB does not reach.
In that case, since the operator Y is the same between the small cell S-eNB and the macro cell M-eNB, the operator Y knows in advance the possibility of interference between the transmission waves, and Measures can be taken to avoid the occurrence of Therefore, the occurrence of interference may occur frequently when the operator Y that operates the macro cell M-eNB is different from the operator X that installs the small cell S-eNB.

Here, the terminal apparatus UE recognizes interference between the transmission wave from the macro cell M-eNB and the transmission wave from the small cell S-eNB. When recognizing the interference, the terminal apparatus UE transmits priority change instruction information for instructing the small cell S-eNB to suppress the transmission wave in order to prioritize communication with the macro cell M-eNB. The small cell S-eNB suppresses a transmission wave to the terminal device UE in response to receiving the priority change instruction information from the terminal device UE. At this time, since the transmission wave from the small cell S-eNB is stopped or the transmission level is reduced, the terminal apparatus UE can efficiently perform communication via the macro cell M-eNB.

(Configuration of base station equipment)
Next, configurations of the macro cell M-eNB and the small cell S-eNB will be described. The configuration of the macro cell M-eNB is the same as that of the small cell S-eNB. In the following description, when the macro cell M-eNB and the small cell S-eNB are not particularly distinguished from each other, both or one of them is collectively referred to as the base station apparatus 10.
FIG. 2 is a block diagram illustrating a configuration of the base station apparatus 10 according to the present embodiment.
The base station apparatus 10 includes a control unit 101, an interference recognition unit 102, an interference processing unit 103, a communication control unit 104, a storage unit 105, a reception unit 106, a transmission unit 107, and a power source 108. Each processing unit is connected to each other through a bus.

The control unit 101 manages and controls the operation of the entire base station apparatus 10. The control unit 101 includes, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and the like.
The interference recognition unit 102 receives interference notification information indicating detection of interference from the terminal device UE via the reception unit 106. By acquiring the interference notification information, the interference recognition unit 102 recognizes the detection of interference in the terminal device UE.
Note that the interference recognition unit 102 may detect the occurrence of interference between the transmission wave from the terminal device UE and another incoming wave based on the reception signal input from the reception unit 106. Other incoming waves are, for example, transmission waves from the small cell S-eNB when the base station device 10 is the macro cell M-eNB.

In one of the macro cell M-eNB and the small cell S-eNB, the interference processing unit 103 receives priority processing request information from the terminal device UE via the receiving unit 106. The priority processing request information is information for requesting that the communication with the terminal device UE by the own device (for example, the macro cell M-eNB) is given priority over the communication by another device (for example, the small cell S-eNB). is there. After receiving the priority processing request information, the interference processing unit 103 immediately transmits priority processing approval information to the terminal device UE. The priority processing approval information is information indicating that a priority processing request for the device itself is approved for the terminal device UE that is a transmission source. Thereafter, the interference processing unit 103 instructs the transmission unit 107 to prioritize communication with the terminal device UE. For example, the interference processing unit 103 increases the output power of the transmission wave transmitted to the terminal device UE with respect to the transmission unit 107.

In the other of the macro cell M-eNB and the small cell S-eNB, when the interference processing unit 103 receives the priority change instruction information from the terminal device UE from the receiving unit 106, the interference processing unit 103 communicates with the terminal device UE to the transmitting unit 107. Is changed so as to lower the priority, that is, the transmission is instructed to be suppressed. Specifically, in that case, the interference processing unit 103 suppresses transmission of a transmission wave addressed to the terminal device UE. Suppression of transmission means reduction of output power or stop of transmission.

The communication control unit 104 controls communication with the terminal device UE. For example, the communication control unit 104 executes processing related to establishment or disconnection of the connection with the terminal device UE. Moreover, the communication control part 104 allocates the resource block (RB: Resource Block) used for transmission / reception of data between the unused frequency bands and the terminal device UE based on the quality information received from the terminal device UE. The RB is a minimum unit of radio resources used for data transmission / reception, that is, a unit bandwidth (for example, 180 kHz) within a unit time (for example, 1 ms). The quality information is information indicating reception quality for each RB, for example, CQI (Channel Quality Indicator).
When interference in the terminal apparatus UE is not detected in the interference recognition unit 102, the communication control unit 104 is based on transmission power information (for example, RNTP: Relative Narrowband TX Power) received from another base station apparatus 10. The above-described inter-cell interference control is executed. An example of inter-cell interference control will be described later.

The storage unit 105 stores various data used in the operation of each unit of the base station device 10, data generated by the operation of each unit of the base station device 10, and software for operating the base station device 10. The storage unit 105 includes, for example, a RAM (Random Access Memory), a ROM (Read-only Memory), and the like.
The receiving unit 106 receives a transmission wave transmitted from another device (for example, the terminal device UE), demodulates the received radio band transmission wave into a baseband received signal, and outputs the received signal to each unit in the base station apparatus 10. To do.
The transmission unit 107 modulates a baseband transmission signal input from each unit of the base station device 10 into a radioband transmission wave, and transmits the modulated transmission wave to another device (for example, the terminal device UE) via an antenna. Send to.
For example, the reception unit 106 and the transmission unit 107 may be configured as a single communication interface.
The power source 108 supplies power necessary for the operation of the base station apparatus 10. The power source 108 includes, for example, a power plug connected to a power line for receiving power supply, a battery that temporarily stores the supplied power, and the like.

(Configuration of terminal device)
Next, the configuration of the terminal device UE will be described.
FIG. 3 is a block diagram illustrating a configuration of the terminal device UE according to the present embodiment.
The terminal device UE includes a control unit 201, an interference recognition unit 202, an interference notification unit 203, a communication control unit 204, a storage unit 205, a reception unit 206, a transmission unit 207, and a power source 208. Each processing unit is connected to each other through a bus.

The control unit 201 manages and controls the operation of the entire terminal device UE. The control unit 201 includes, for example, a CPU, a DSP, and the like.
The interference recognition unit 202 determines whether interference has been detected as the reception state of the transmission wave from the base station apparatus 10. For example, the interference recognition unit 202 determines that interference has been detected when a reference signal reception quality (RSRP: Reference Signal Received Power) for each RB of a reception signal received by the reception unit 206 is higher than a predetermined RSRP threshold. To do. RSRP is a ratio of reference signal received power (RSRP: Reference Signal Received Power) to received signal strength (RSSI: Received Signal Strength Indicator) of the entire system band. The interference recognition unit 202 determines that interference is not detected when the RSRP is equal to or less than a predetermined RSRP threshold. The interference recognition unit 202 outputs interference notification information indicating the detection of interference to the interference notification unit 203.

When the interference notification information is input from the interference recognition unit 202, the interference notification unit 203 transmits the input interference notification information to the macro cell M-eNB via the transmission unit 207. In this case, the interference notification unit 203 generates priority processing request information for requesting that communication with the own device (terminal device UE) by the macro cell M-eNB is given priority over communication by the small cell S-eNB. . The interference notification unit 203 transmits the generated priority processing request information to the macro cell M-eNB via the transmission unit 207.

The interference notification unit 203 receives the priority processing approval information from the macro cell M-eNB via the reception unit 206 as a response to the transmission of the priority processing request information. After receiving the priority processing approval information, the interference notification unit 203 generates priority change instruction information, and transmits the generated priority change instruction information to the small cell S-eNB via the transmission unit 207. The priority change instruction information transmitted to the small cell S-eNB is information that instructs suppression of transmission from the small cell S-eNB.

The communication control unit 204 controls communication with the base station apparatus 10. For example, the communication control unit 204 performs processing related to location registration in a public wireless communication network connected to the macro cell M-eNB. In addition, the communication control unit 204 executes processing related to establishment and disconnection of connections with the macro cell M-eNB and the small cell S-eNB. Further, the communication control unit 204 measures the reception quality for each RB for each of the macro cell M-eNB and the small cell S-eNB, and generates quality information, for example, CQI indicating the measured reception quality. The communication control unit 204 transmits the generated quality information to each of the macro cell M-eNB and the small cell S-eNB via the transmission unit 207.

The storage unit 205 stores various data used in the operation of each unit of the terminal device UE, data generated by the operation of each unit of the terminal device UE, and software for operating the terminal device. The storage unit 205 includes, for example, a RAM, a ROM, and the like.
The reception unit 206 receives the transmission wave transmitted by the base station apparatus 10, demodulates the received transmission wave of the radio band into a reception signal of the base band, and outputs it to each unit of the terminal apparatus UE.
The transmission unit 207 modulates a baseband transmission signal input from each unit of the terminal device UE into a radio band transmission wave, and transmits the modulated transmission wave to another device (for example, the terminal device UE) via an antenna. Send.
For example, the reception unit 206 and the transmission unit 207 may be configured as a single communication interface.
The power supply 208 supplies power required for the operation of the terminal device UE. The power source 208 includes, for example, a power plug connected to a power line for receiving power supply, a battery that temporarily stores the supplied power, and the like.

(Inter-cell interference control)
Next, an example of inter-cell interference control will be described. Inter-cell interference control described below is performed between the macro cell M-eNB and the small cell S-eNB when no interference is detected in the terminal device UE.
FIG. 4 is a sequence diagram illustrating an example of inter-cell interference control.
(Step S101) The communication control unit 104 of the macro cell M-eNB determines allocation of RBs used for communication with the terminal device UE. Thereafter, the process proceeds to step S102.
(Step S102) The communication control unit 104 of the macro cell M-eNB determines the transmission power for each allocated RB, for example, using a method prescribed in LTE. The communication control unit 104 of the macro cell M-eNB determines whether or not the power ratio of the transmission power to the average transmission power of the entire system band for each RB exceeds a predetermined power ratio threshold. The communication control unit 104 of the macro cell M-eNB sets the signal value to 1 for RBs for which the power ratio exceeds a predetermined ratio threshold, and sets the signal value to 0 for RBs for which the power ratio does not exceed the predetermined ratio threshold. Transmission power information RNTP is generated. The communication control unit 104 transmits the generated transmission power information RNTP to the small cell S-eNB. Thereafter, the process proceeds to step S103.

(Step S103) The communication control unit 104 of the small cell S-eNB receives the transmission power information RNTP from the macro cell M-eNB. Thereafter, the process proceeds to step S104.
(Step S104) The communication control unit 104 of the small cell S-eNB recognizes that there is a possibility of interference for RBs whose signal value indicated by the transmission power information RNTP is 1, and interference occurs for other RBs. Recognize that there is no possibility. Thereafter, the process proceeds to step S105.
(Step S105) The communication control unit 104 of the small cell S-eNB determines that an RB whose signal value indicated by the transmission power information RNTP is 1 is not used for communication with the terminal apparatus UE. The communication control unit 104 of the small cell S-eNB generates RB non-use notification information indicating an RB determined not to be used, and transmits the generated RB non-use notification information to the macro cell M-eNB. Thereafter, the process proceeds to step S106.

(Step S106) The communication control unit 104 of the macro cell M-eNB receives RB non-use notification information from the small cell S-eNB, and the small cell S-eNB uses the RB allocated for communication with the terminal device UE. It is determined that no interference occurs. Thereafter, the communication control unit 104 of the macro cell M-eNB starts communication with the terminal device UE using the allocated RB. Thereafter, the process shown in FIG.

(Communication processing)
In the process shown in FIG. 4, the macro cell M-eNB and the small cell S-eNB receive the quality information between the cells measured by the terminal apparatus UE, and each cell receives the quality information for each RB based on the received quality information. Recognize communication quality. Since the macro cell M-eNB and the small cell S-eNB determine RB allocation based on the recognized communication quality, a long time is required for processing. In the present embodiment, the processing time can be shortened by the communication processing described below. FIG. 5 is a sequence diagram showing communication processing according to the present embodiment.
The process shown in FIG. 5 is started when the terminal apparatus UE is communicating via the macro cell M-eNB and the small cell S-eNB.

(Step S201) The interference recognition unit 202 of the terminal device UE determines whether or not interference has been detected for transmission waves from the macro cell M-eNB and the small cell S-eNB. If interference is detected, the process proceeds to step S202.
(Step S202) The interference notification unit 203 of the terminal apparatus UE transmits interference notification information for notifying the detection of interference to the macro cell M-eNB. Thereafter, the process proceeds to step S203.
(Step S203) The interference notifying unit 203 of the terminal device UE transmits priority processing request information for requesting that the communication by the macro cell M-eNB has priority over the communication by the small cell S-eNB to the macro cell M-eNB. To do. Thereafter, the process proceeds to step S204.
(Step S204) Immediately after receiving the priority processing request information from the terminal device UE, the interference processing unit 103 of the macro cell M-eNB transmits priority processing approval information indicating that the priority processing request has been approved to the terminal device UE. Thereafter, the process proceeds to step S205.

(Step S205) After receiving the priority processing approval information from the macro cell M-eNB, the interference notification unit 203 of the terminal device UE transmits priority change instruction information indicating suppression of transmission to the small cell S-eNB. Thereafter, the process proceeds to step S206.
(Step S206) The interference processing unit 103 of the small cell S-eNB reduces the output power of the transmission wave with respect to the transmission unit 107 of the own device. Note that the interference processing unit 103 of the small cell S-eNB may stop the transmission unit 107 of its own device from transmitting a transmission wave. Thereafter, the process proceeds to step S207.
(Step S207) The interference processing unit 103 of the macro cell M-eNB increases the output power of the transmission wave to the transmission unit 107 of the own device. Thereafter, the process shown in FIG.

In the above description, when the terminal apparatus UE recognizes interference mainly, the priority change instruction information is transmitted to the small cell S-eNB, and transmission from the small cell S-eNB to the terminal apparatus UE is suppressed. However, the present invention is not limited to this. When recognizing interference, the terminal apparatus UE may transmit priority change instruction information to the macro cell M-eNB instead of the small cell S-eNB. The macro cell M-eNB suppresses a transmission wave to the terminal device UE in response to receiving the priority change instruction information from the terminal device UE. Thereby, the terminal device UE can efficiently perform communication via the small cell S-eNB. The transmission of the priority change instruction information to the macro cell M-eNB may be limited to a case where it is difficult to start communication via the small cell S-eNB. In such a case, for example, immediately after the end of communication via the small cell S-eNB, a separate process having a higher priority than the communication may be assigned and an application program related to the process may be executed. is there.

As described above, the communication system 1 according to the present embodiment has the interference recognition unit 202 that recognizes interference between a transmission wave from the macro cell M-eNB and a transmission wave from the small cell S-eNB in the terminal device UE. Is provided. The terminal apparatus UE includes an interference notification unit 203 that transmits priority change instruction information that instructs the small cell S-eNB to suppress transmission when the interference recognition unit 202 recognizes interference. Further, the small cell S-eNB includes an interference processing unit 103 that suppresses transmission to the terminal device UE when receiving priority change instruction information from the terminal device UE.
With this configuration, the interference generated in the terminal apparatus UE is immediately recognized in the small cell S-eNB, and the transmission wave from the small cell S-eNB is suppressed immediately after the interference is recognized. Therefore, interference can be reduced in a short time, and communication with high utilization efficiency of radio resources can be realized.

In the communication system 1 according to the present embodiment, when the interference recognizing unit 202 recognizes interference, the interference notifying unit 203 of the terminal device UE transmits priority processing request information instructing transmission with priority over the small cell S-eNB. To do.
With this configuration, since the ratio of the signal component to the interference component recognized by the terminal device UE increases, the communication quality can be further improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. About the same structure as embodiment mentioned above, the same number is attached | subjected and description is used.
FIG. 6 is a conceptual diagram illustrating an example of the communication system 1 according to the present embodiment. The communication system 1 includes a macro cell M-eNB, a small cell S-eNB, and three terminal apparatuses UE1 to UE3. The macro cell area MC includes a small cell area SC. The configurations of the terminal apparatuses UE1 to UE3 are the same as the configuration of the UE described above. A solid line arrow indicates that communication is performed wirelessly between the macro cell M-eNB and each of the terminal apparatuses UE1 to UE3. A broken arrow indicates that communication is performed wirelessly between the small cell S-eNB and each of the terminal apparatuses UE1 to UE3. Therefore, in each of the terminal apparatuses UE1, UE2, and UE3, in addition to interference between the transmission wave from the macro cell M-eNB and the transmission wave from the small cell S-eNB, the terminal apparatuses UE1 to UE3 from the small cell S-eNB Interference may occur between the transmission waves addressed to each of the. However, when the interference wave is suppressed in any one of the three terminal apparatuses UE1 to UE3 (for example, the terminal apparatus UE1), if the power of the transmission wave from the small cell S-eNB is simply reduced, the other terminal apparatuses (For example, communication with UE2, UE3) may be hindered.

Therefore, in the present embodiment, as illustrated in FIG. 6, when interference is detected in the terminal device UE1, the small cell S-eNB forms a null NB in the direction of the terminal device UE1. Null NB is a range in the direction in which the power of the transmission wave is lower than the surrounding area. The formation of the null NB corresponds to a process opposite to the beam forming that increases the power of the transmission wave in a specific direction.

(Configuration of base station equipment)
Next, the configuration of the base station apparatus 10 according to this embodiment will be described. In the following description, the base station apparatus 10 means the small cell S-eNB shown in FIG.
FIG. 7 is a block diagram showing a configuration of the base station apparatus 10 according to the present embodiment.
The base station apparatus 10 according to the present embodiment is configured to further include a GPS (Global Positioning System) receiving unit 109 in the base station apparatus 10 shown in FIG.
The base station apparatus 10 includes N (an integer greater than or equal to a predetermined 2) antennas in the transmission unit 107, and can transmit transmission waves related to transmission signals of maximum N streams. In addition, the base station apparatus 10 includes N antennas in the reception unit 106, and can receive reception signals of maximum N streams. Further, the communication control unit 104 can control transmission of a maximum N stream transmission signal and reception of a maximum N stream reception signal. In addition, the communication control unit 104 performs transmission / reception with each of the plurality of terminal apparatuses UE by time division multiplexing (TDD: Time Division Duplex) in different time zones between the terminal apparatuses UE. The operation of the transmission unit 107 may be controlled. Because of this control, transmission waves addressed to each of the plurality of terminal apparatuses UE are not transmitted at the same time, so that interference between these transmission waves does not occur.

The GPS receiver 109 receives signals arriving from at least four GPS satellites, and calibrates time information serving as a reference for synchronizing the signals. Then, the GPS receiving unit 109 accurately measures its own position (latitude, longitude) based on the arrival time difference between the received signals. The GPS receiving unit 109 generates self-position information indicating the measured self-position, and outputs the generated self-position information to the interference processing unit 103.

Self-position information is input from the GPS receiver 109 to the interference processor 103. On the other hand, when receiving the priority change instruction information from the terminal apparatus UE, the interference processing unit 103 generates terminal position request information for requesting position information from the terminal apparatus UE, and generates the generated terminal position request information. Is transmitted to the terminal device UE via the transmission unit 107. As a response, the interference processing unit 103 receives terminal position information indicating the position of the terminal device UE from the terminal device UE via the receiving unit 106.

The interference processing unit 103 specifies the direction of the terminal device UE indicated by the terminal position information on the basis of its own position indicated by the self-position information, and stores a precoding matrix having directivity having null in the specified direction. Read from. The interference processing unit 103 multiplies the read precoding matrix by a transmission vector having the transmission signal of each stream as an element, and calculates a transmission vector having the transmission signal to each antenna as an element. The interference processing unit 103 outputs the calculated transmission vector to the transmission unit 107.
Therefore, the transmitting unit 107 transmits a transmission wave in which a null is formed in the direction of the terminal device UE as a transmission wave based on a transmission signal that is an element of the calculated transmission vector.

(Configuration of terminal device)
Next, the configuration of the terminal device UE according to the present embodiment will be described.
FIG. 8 is a block diagram illustrating a configuration of the terminal device UE according to the present embodiment.
The terminal device UE according to the present embodiment is configured to further include a GPS receiving unit 209 in the terminal device UE shown in FIG.
When receiving the terminal location request information from the base station device 10 via the receiving unit 206, the GPS receiving unit 209 receives signals arriving from at least four GPS satellites, respectively, and provides a reference for synchronizing the signals. The time information is corrected. Then, the GPS receiving unit 209 accurately measures its own position based on the arrival time difference between the received signals. The GPS reception unit 209 generates terminal position information indicating the measured position of itself, and transmits the generated terminal position information to the base station device 10 via the transmission unit 207.

(Communication processing)
Next, communication processing according to the present embodiment will be described.
FIG. 9 is a sequence diagram showing communication processing according to the present embodiment. The process shown in FIG. 9 includes the processes of steps S201 to S205 and the processes of steps S301 to S304. The description of FIG. 5 is used for the processing of steps S201 to S205. In the process shown in FIG. 9, the processes of steps S301 to S303 are executed at the time of position registration immediately after activation of the terminal apparatus UE and at the time of changing the position registration area. Note that the processing in steps S301 to S303 may be repeated periodically.

(Step S301) After receiving the priority change instruction information from the terminal device UE, the interference processing unit 103 of the small cell S-eNB generates terminal location request information, and transmits the generated terminal location request information to the terminal device UE. (Location information request). Thereafter, the process proceeds to step S302.
(Step S302) When receiving the terminal position request information from the base station apparatus 10, the GPS receiving unit 209 of the terminal apparatus UE measures its own position based on a received signal that has arrived from a GPS satellite. Thereafter, the process proceeds to step S303.
(Step S303) The GPS reception unit 209 of the terminal device UE generates terminal position information indicating the measured position of itself, and transmits the generated terminal position information to the small cell S-eNB.
Then, after the interference is detected in step S201, the processing in steps S202 to S205 is executed. After the process of step 205 is completed, the process proceeds to step S304.

(Step S304) The interference processing unit 103 of the small cell S-eNB specifies the direction of the terminal device UE indicated by the terminal location information received from the terminal device UE with reference to the own location indicated by the self location information. The interference processing unit 103 of the small cell S-eNB multiplies a transmission vector having the transmission signal of each stream as an element by a precoding matrix having directivity that forms nulls in the specified direction, and transmits the transmission signal to each antenna. A transmission vector having the element as an element is calculated. Each antenna of the transmission unit 107 transmits a transmission wave based on the transmission signal of each element of the calculated transmission vector. Thereafter, the process shown in FIG. 9 ends.

In addition, although the case where interference was detected in one terminal device UE1 at a time was taken as an example in the above description, the present invention is not limited to this. Therefore, a plurality of precoding matrices that provide directivity possessed by a plurality of regions (sectors) having lower transmission power than the surroundings may be stored in advance in the storage unit 105 of the small cell S-eNB. Assume that the arrangement of the regions differs between different precoding matrices.
Then, the interference processing unit 103 of the small cell S-eNB selects a precoding matrix having directivity included in each region of each of the plurality of terminal apparatuses UE. The interference processing unit 103 multiplies the selected precoding matrix by a transmission vector having the transmission signal of each stream as an element, and calculates a transmission vector having the transmission signal to each antenna as an element.
Therefore, as illustrated in FIG. 10, the position of the terminal device UE1 to be controlled is included in the region SB1 where the transmission power of the transmission wave from the small cell S-eNB is low. Therefore, in the terminal device UE1, in addition to the transmission wave addressed to the terminal device UE1 from the macro cell M-eNB, the transmission wave addressed to each of the terminal devices UE2 and UE3 from the small cell S-eNB, and the terminal device from the small cell S-eNB to the terminal device Interference with the transmission wave addressed to UE1 is suppressed.

Note that the GPS receiving unit 209 of the terminal device UE may measure its own position at predetermined time intervals without receiving the terminal position request information. In that case, the interference processing unit 103 of the small cell S-eNB can omit generation and transmission of terminal location request information.
Further, if the position of the small cell S-eNB according to the present embodiment is fixed and the self-location information is stored in the interference processing unit 103 in advance, the GPS receiving unit 109 can be omitted.

As described above, in the communication system 1 according to the present embodiment, the terminal apparatus UE detects the position of the terminal apparatus UE, and transmits the position information indicating the detected position to the small cell S-eNB. Is provided. In the small cell S-eNB, the interference processing unit 103 makes the intensity of the transmission wave to the area including the position indicated by the position information received from the terminal apparatus UE lower than the intensity of the transmission wave to the other area. Here, the GPS receiving unit 209 is taken as an example of the position detecting unit that detects its own position, but the position detecting unit is not limited to this, and may be, for example, an optical position sensor or an infrared position. It may be a sensor. As a result, it is possible to detect its own position even indoors or underground where it is difficult for signals from the GSP satellite to arrive.
Therefore, since the area | region where interference is suppressed can be limited to the area | region containing the position of each terminal device UE, the influence of each process can suppress the influence on communication of another terminal device UE.

(Third embodiment)
Next, a third embodiment of the present invention will be described. About the same structure as embodiment mentioned above, the same number is attached | subjected and description is used.
FIG. 11 is a conceptual diagram illustrating an example of the communication system 1 according to the present embodiment. FIG. 11 shows that the terminal apparatuses UE1 to UE3 are located in the macro cell area MC at a certain point in time. The terminal apparatus UE1 is located at the peripheral edge (cell edge) of the small cell area SC, and communication is performed between the macro cell M-eNB and the small cell S-eNB. The terminal device UE2 communicates with the small cell S-eNB, but does not communicate with the macro cell M-eNB. The terminal device UE3 communicates with the macro cell M-eNB, but does not communicate with the small cell S-eNB. In this situation, the transmission wave from the macro cell M-eNB interferes with the transmission wave from the small cell S-eNB in the terminal device UE1, and the terminal devices UE1 and UE2 located in the small cell area SC Interference may occur between the transmission waves addressed to each.

As described above, the communication control unit 104 of the macro cell M-eNB and the small cell S-eNB allocates RBs to each terminal apparatus UE located in each predetermined time. Therefore, as will be described next, the terminal device of the communication partner may change over time.
FIG. 12 is a timing chart showing an example of the communication status of the communication system 1 according to the present embodiment. The upper and lower sections of FIG. 12 show whether or not each of the macro cell M-eNB and the small cell S-eNB is communicating, and the partner terminal apparatus in communication. The macro cell M-eNB performs communication with the terminal apparatuses UE1, UE3, and UE3 during the periods of time t1 to t2, t2 to t3, and t3 to t4, respectively. The small cell S-eNB does not communicate during the time t1 to t2 and t3 to t4, but communicates with the UE 2 during the time t2 to t3, but does not communicate with the small cell area SC. No communication is performed with the terminal device UE1 that is in the area. Therefore, no interference occurs between the transmission waves addressed from the small cell area SC to each of the terminal apparatuses UE1 and UE2. Thus, in the present embodiment, for example, when interference is recognized in the terminal device UE1, the small cell S-eNB stops transmission of a transmission signal to the terminal device UE1.

(Communication processing)
Next, communication processing according to the present embodiment will be described. FIG. 13 is a sequence diagram illustrating communication processing according to the present embodiment. The process shown in FIG. 13 includes the processes of steps S201, S202, and S207, and the processes of steps S401 to S404. The description of FIG. 5 is used for the processing of steps S201 to S205. In the process shown in FIG. 13, the process proceeds to step S401 after the processes of steps S201 and S205 are completed.

(Step S401) The interference notifying unit 203 of the terminal device UE generates temporary stop notification information indicating that a temporary stop of communication by the small cell S-eNB is notified, and the generated temporary stop notification information is displayed in the macro cell M- Send to eNB. Thereafter, the process proceeds to step S402.
(Step S402) The interference processing unit 103 of the macro cell M-eNB immediately receives the temporary stop notification information from the terminal apparatus UE, and immediately after the reception of the temporary stop notification information indicating the approval of the temporary stop of communication with the small cell S-eNB. Is generated. The interference processing unit 103 transmits the generated stop process approval information to the terminal device UE. Thereafter, the process proceeds to step S403.

(Step S403) After receiving the stop process approval information from the macro cell M-eNB, the interference notification unit 203 of the terminal device UE generates transmission stop instruction information indicating stop of transmission, and the generated transmission stop instruction information is set to the small cell. Send to S-eNB. Thereafter, the process proceeds to step S404.
(Step S404) The interference processing unit 103 of the small cell S-eNB cancels allocation of RBs related to communication with the terminal device UE that is the transmission source of the transmission stop instruction information to the communication control unit 104 of the own device. The communication with the terminal device UE is stopped by releasing the RB. After executing step S207, the macro cell M-eNB ends the process illustrated in FIG.

FIG. 14 is a timing chart showing another example of the communication status of the communication system 1 according to the present embodiment. FIG. 14 shows the communication status shown in FIG. 14, whether the macro cell M-eNB and the small cell S-eNB are in communication when the communication process shown in FIG.
In the example shown in FIG. 14, between times t1 and t2, the macro cell M-eNB and the small cell S-eNB communicate with the terminal devices UE3 and UE2, respectively.
(1) At time t2, the macro cell M-eNB and the small cell S-eNB each start communication with the terminal device UE1.
(2-1) Thereafter, at time t3, the interference recognition unit 202 of the terminal apparatus UE1 detects interference (step S201). The interference notification unit 203 of the terminal device UE1 executes steps S202, S401, and S402 with the macro cell M-eNB.
(2-2) At time t4, the interference notification unit 203 of the terminal device UE1 transmits transmission stop instruction information to the small cell S-eNB (step S403). Thereafter, the interference processing unit 103 of the small cell S-eNB stops communication with the terminal device UE (step S404).
(3) From time t4 to t5, the terminal apparatus UE1 performs communication with the macro cell M-eNB without causing interference.
(4) During the period from time t5 to t6, the macro cell M-eNB and the small cell S-eNB communicate with the terminal apparatuses UE3 and UE2, respectively. In this case, since the counterparts of the macro cell M-eNB and the small cell S-eNB are different from each other, there is no interference between the transmission waves addressed to each.

In addition, although this embodiment has exemplified the case where the number of terminal devices located in the small cell area SC is mainly three, the present invention is not limited to this. The number of terminal devices may be two, or four or more.

As described above, in the communication system 1 according to the present embodiment, the macro cell M-eNB and the small cell S-eNB change the communication destination terminal apparatus UE from the terminal apparatus UE located in each area to the predetermined time intervals. A communication control unit 104 is provided. Further, the interference processing unit 103 of the small cell S-eNB stops communication with the terminal apparatus UE that has transmitted the transmission stop instruction information to the communication control unit 104.
With this configuration, when interference of a transmission wave is detected when the macro cell M-eNB and the small cell S-eNB determine a communication destination terminal device independently with time, the small cell S-eNB Communication with the detected terminal device UE stops. Therefore, when there are a plurality of terminal apparatuses UE located in the small cell S-eNB, communication can be performed in a state where there is no interference between transmission waves addressed to each of the plurality of terminal apparatuses UE.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. About the same structure as embodiment mentioned above, the same number is attached | subjected and description is used.
FIG. 15 is a conceptual diagram illustrating an example of the communication system 1 according to the present embodiment. The communication system 1 includes one macro cell M-eNB and two small cells S-eNB1 and S-eNB2. The small cell areas S-C1 and S-C2 are the cell areas of the small cells S-eNB1 and S-eNB2, and a part of them overlaps each other. Further, the small cell areas S-C1 and S-C2 overlap with the macro cell area MC, respectively. In the example shown in FIG. 15, two terminal apparatuses UE1 and UE2 are located in an area where the small cell areas S-C1 and S-C2 overlap each other.
Under this situation, when the terminal devices UE1 and UE2 communicate with the small cells S-eNB1 and S-eNB2, respectively, the terminal device UE1 transmits a transmission wave from the small cell S-eNB1 addressed to the own device, and the terminal device. Interference with a transmission wave from the small cell S-eNB 2 addressed to the UE 2 may occur. Further, in the terminal device UE2, there may be interference between a transmission wave from the small cell S-eNB2 addressed to the own device and a transmission wave from the small cell S-eNB1 addressed to the terminal device UE1.

Therefore, the communication system 1 according to the present embodiment has a configuration described below. Each of the terminal devices UE1 and UE2 detects the position of the own device in the GPS receiving unit 209, and transmits terminal position information indicating the detected position to the small cells S-eNB1 and S-eNB2 that are communicating with the respective devices. In the small cells S-eNB1 and S-eNB2, the interference processing unit 103 determines the intensity of the transmission wave to the area including the position indicated by the terminal position information received from each of the terminal apparatuses UE1 and UE2 Higher than the strength of. The interference processing unit 103 can use a technique similar to the technique for reducing the intensity of the transmission wave described with reference to FIG. 9 as a technique for increasing the intensity of the transmission wave.

With this configuration, as shown in FIG. 16, the small cells S-eNB1 and S-eNB2 respectively transmit regions (beams and sectors) SB1 and SB2 having higher transmission wave strengths than the surrounding regions to the terminal devices UE1 and UE2. Can be directed in the direction of Therefore, the strengths of the transmitted waves from the small cells S-eNB2 and S-eNB1 addressed to the terminal devices UE2 and UE1 respectively arriving at the terminal devices UE1 and UE2 are small cells S-eNB1 and S-eNB2 related to communication. It becomes relatively lower than the intensity of the transmitted wave from. As a result, it is possible to suppress interference that occurs in the terminal apparatuses UE1 and UE2. In particular, the effect increases as the directions between the terminal apparatuses UE1 and UE2 from the small cells S-eNB1 and S-eNB2 are separated from each other, or as the region where the intensity of the transmission wave is high is narrow.

(Modification)
Next, a modification of this embodiment will be described. FIG. 17 is a block diagram of the communication system 1 according to this modification. In FIG. 17, illustration of the terminal apparatuses UE1 and UE2 is omitted. The communication system 1 includes one macro cell M-eNB, two small cells S-eNB1, S-eNB2, and an operation management unit 30. The operation management unit 30 may be configured as a separate device from the macro cell M-eNB, the small cell S-eNB1, and the S-eNB 2, or may be configured as a part of the macro cell M-eNB.

The operation management unit 30 manages the operations of the small cells S-eNB1 and S-eNB2. As described with reference to FIGS. 13 and 14, the small cells S-eNB1 and S-eNB2 use the communication control unit 104 to select a communication destination terminal apparatus UE from among the existing terminal apparatuses UE for a predetermined time. Set for each. In this modification, before starting data transmission to the communication destination determined by the communication control unit 104, the interference processing unit 103 transmits transmission permission request information for requesting permission to transmit data to the communication destination. Generate. The interference processing unit 103 transmits the generated transmission permission request information to the operation management unit 30. Immediately after receiving the transmission permission information from the operation management unit 30 as a response, the interference processing unit 103 causes the communication control unit 104 to start transmitting data to the communication destination. The communication control unit 104 transmits transmission start information and transmission end information to the operation management unit 30 at the start of data transmission and at the end of transmission, respectively.

The operation management unit 30 determines whether data is transmitted in each of the small cells S-eNB1 and S-eNB2 based on the transmission management information and the transmission end information received from the small cells S-eNB1 and S-eNB2, respectively. Can be determined.
The operation management unit 30 receives the transmission permission request information from the small cells S-eNB1 and S-eNB2, and any of the small cells other than the small cell (for example, S-eNB1) that transmitted the transmission permission request information (for example, S-eNB1) , S-eNB 2) determines whether data is being transmitted. When it is determined that no small cell (for example, S-eNB 2) is transmitting data, the operation management unit 30 immediately permits transmission and transmits the transmission permission request information to the small cell (for example, S-eNB 1). Send permission information to. In this case, if the operation management unit 30 that does not cause interference in the terminal devices UE1 and UE2 determines that any of the small cells (for example, the S-eNB 2) is also transmitting data, the data transmission ends. Wait until Thereafter, the operation management unit 30 permits transmission and transmits the transmission permission information to the small cell (for example, S-eNB 1) that has transmitted the transmission permission request information.

When the operation management unit 30 simultaneously receives transmission permission request information from the small cells S-eNB1 and S-eNB2, the operation management unit 30 sets the transmission order for transmitting the transmission permission information between the small cells S-eNB1 and S-eNB2. Determine. For example, the operation management unit 30 increases the transmission order as the priority of the transmission data related to the transmission permission request information increases. The priority of transmission data is so high that high real-time property and urgency are required. For example, the priority of moving images is higher than that of text and still images, and the priority of calling voice is higher than that of moving images. Moreover, the priority of the emergency call is higher than the normal information transmission. In addition, the operation management unit 30 advances the transmission order of the transmission permission information related to the terminal device UE that has not detected the interference rather than the transmission permission information related to the terminal device UE that has detected the interference. The operation management unit 30 sets the transmission order earlier in the transmission permission information related to the terminal apparatus UE that has detected the interference as the terminal apparatus UE has a lower interference detection frequency. The operation management unit 30 can determine the presence / absence of interference detection and the frequency of interference detection for each terminal device UE by receiving the interference notification information transmitted by the terminal device UE that has detected interference.

With the configuration described above, the communication control unit 104 of the small cells S-eNB1 and S-eNB2 avoids simultaneous communication between the plurality of terminal apparatuses UE1 and UE2 as shown in FIG. 18, and performs communication in different time zones. Do.
FIG. 18 is a timing chart showing an example of the communication status of the communication system 1 according to this modification. 18 shows whether or not each small cell S-eNB1 and S-eNB2 is communicating, and the partner terminal device during communication. The small cell S-eNB1 performs communication with the terminal device UE1 during the period of time t1 to t2, and t3 to t4, and does not perform communication during the period of time t2 to t3. On the other hand, the small cell S-eNB2 performs communication with the terminal device UE2 during the period of time t2 to t3, and does not perform communication during the period of time t1 to t2 and t3 to t4. Therefore, in the terminal devices UE1 and UE2 that are located in an area where the small cell areas S-C1 and S-C2 overlap, transmission waves addressed to the respective devices from the small cells S-eNB1 and S-eNB2, Interference with the transmission waves from the small cells S-eNB2 and S-eNB1 is avoided.

Although the present embodiment has exemplified the case where the number of small cells where the small cell areas overlap each other is mainly two in the macro cell area MC, the present invention is not limited to this.
The number of small cells where the small cell areas overlap may be three or more, and the number of regions where the small cell areas overlap may be two or more. In the communication system 1 according to the present embodiment, the macro cell M-eNB may be omitted.

As described above, the communication system 1 according to the present embodiment includes a plurality of small cells S-eNB1 and S-eNB each having a region where the small cell areas S-C1 and S-C2 overlap each other. When a plurality of terminal apparatuses UE1 and UE2 are located in an overlapping area, the interference processing unit 103 of each of the small cells S-eNB1 and S-eNB is different in time or space for each of the terminal apparatuses UE1 and UE2. The transmission of data to one of the terminal devices UE1 and UE2 is prioritized over other terminal devices.
With this configuration, the terminal devices UE1 and UE2 that are located in the area where the small cell areas S-C1 and S-C2 overlap each other cause interference of transmission waves from the small cells S-eNB2 and S-eNB1, respectively. Communication is possible in situations where there is no such situation.

The embodiment of the present invention has been described above with reference to the drawings. However, the specific configuration is not limited to the above-described configuration, and various design changes such as combinations can be made without departing from the gist of the present invention. It is possible to omit a part of the configuration.

The embodiment described above can also be implemented in the following manner.
(1) A communication system including a first base station apparatus, a second base station apparatus, and a terminal apparatus, wherein the terminal apparatus transmits a transmission wave from the first base station apparatus, and the second base station An interference recognition unit for recognizing interference with a transmission wave from the device, and an interference notification unit for transmitting a suppression instruction for instructing suppression of transmission to the second base station device when the interference recognition unit recognizes interference, And the second base station device includes an interference processing unit that suppresses transmission to the terminal device when receiving the suppression instruction from the terminal device.

(2) When the interference recognizing unit recognizes the interference, the interference notification unit of the terminal device transmits a priority processing request instructing the first base station device to perform transmission with priority over the second base station device. The communication system according to (1), wherein the first base station device includes an interference processing unit that prioritizes transmission to the terminal device when receiving a priority processing request from the terminal device.

(3) In the second base station device, the terminal device detects a position of the device itself, and transmits position information indicating the position to the second base station device. The communication system according to (1) or (2), wherein the intensity of the transmission wave to the area including the position indicated by the position information received from the terminal device is lower than the intensity of the transmission wave to the other area.

(4) The first base station device and the second base station device each include a communication control unit that determines a communication destination terminal device from a terminal device residing in each of the first base station device and the second base station device. In the apparatus, the interference processing unit causes the communication control unit to stop communication with the terminal device that has transmitted the suppression instruction.

(5) comprising a plurality of the second base station devices having areas where the cell areas overlap each other, and when the plurality of terminal devices are located in the area, the interference processing unit of the second base station device is: The communication system according to any one of (1) to (4), wherein transmission of data to one of the terminal devices is given priority over other terminal devices at different times or in a space between the terminal devices.

(6) An interference recognition unit for recognizing interference between a transmission wave from the first base station device and a transmission wave from the second base station device, and when the interference recognition unit recognizes interference, the second base station An interference notification unit that transmits a suppression instruction that instructs the apparatus to suppress transmission.

(7) A communication method in a terminal apparatus, wherein an interference recognition process for recognizing interference between a transmission wave from a first base station apparatus and a transmission wave from a second base station apparatus, and interference in the interference recognition process An interference notification step of transmitting a suppression instruction to instruct the second base station apparatus to suppress transmission when recognized.

(8) An interference recognition procedure for recognizing interference between a transmission wave from the first base station apparatus and a transmission wave from the second base station apparatus having a cell area smaller than that of the first base station apparatus in the computer of the terminal apparatus A program for executing an interference notification procedure for transmitting a suppression instruction for instructing the second base station apparatus to suppress transmission when interference is recognized in the interference recognition procedure.

In addition, a part of the base station device 10, for example, the control unit 101, the interference recognition unit 102, the interference processing unit 103 and the communication control unit 104, a part of the terminal device UE, for example, the control unit 201, the interference recognition unit 202, the interference The notification unit 203 and the communication control unit 204 may be realized by a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed.
Moreover, you may implement | achieve part or all of the base station apparatus 10 in the embodiment mentioned above, and the terminal device UE as integrated circuits, such as LSI (Large Scale Integration). Each functional block of the base station apparatus 10 and a part of the terminal apparatus UE may be individually made into a processor, or part or all of them may be integrated into a processor. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to the advancement of semiconductor technology, an integrated circuit based on the technology may be used.

DESCRIPTION OF SYMBOLS 1 ... Communication system 10 (M-eNB, S-eNB, S-eNB1, S-eNB2) ... Base station apparatus 101 ... Control part 102 ... Interference recognition part 103 ... Interference processing part 104 ... Communication control part 105 ... Storage part 106 ... Receiving unit 107 ... Transmitting unit 108 ... Power supply 109 ... GPS receiving unit UE (UE1, UE2, UE3) ... Terminal device 201 ... Control unit 202 ... Interference recognition unit 203 ... Interference notification unit 204 ... Communication control unit 205 ... Storage unit 206 ... Reception unit 207 ... Transmission unit 208 ... Power source 209 ... GPS reception unit

Claims (5)

1. A communication system comprising a first base station device, a second base station device, and a terminal device,
   The terminal device
   An interference recognition unit for recognizing interference between a transmission wave from the first base station apparatus and a transmission wave from the second base station apparatus;
   When the interference recognition unit recognizes interference, an interference notification unit that transmits a suppression instruction that instructs the second base station device to suppress transmission, the second base station device includes:
   A communication system comprising: an interference processing unit that suppresses transmission to the terminal device when receiving the suppression instruction from the terminal device.
2. When the interference recognition unit recognizes interference, the interference notification unit of the terminal device transmits a priority processing request that instructs the first base station device to give priority to transmission over the second base station device,
   The first base station apparatus
   The communication system according to claim 1, further comprising: an interference processing unit that prioritizes transmission to the terminal device when receiving a priority processing request from the terminal device.
3. The terminal device
   A position detection unit that detects the position of the own device and transmits position information indicating the position to the second base station device;
   In the second base station apparatus,
   The interference processing unit
   The communication system according to claim 1 or 2, wherein the intensity of a transmission wave to an area including a position indicated by position information received from the terminal device is lower than an intensity of a transmission wave to another area.
4. The first base station device and the second base station device each include a communication control unit that determines a communication destination terminal device from a terminal device located in each of the first base station device every predetermined time,
   In the second base station apparatus,
   The communication system according to any one of claims 1 to 3, wherein the interference processing unit causes the communication control unit to stop communication with a terminal device that has transmitted the suppression instruction.
5. A plurality of the second base station devices having areas where the cell areas overlap each other;
   When a plurality of the terminal devices are located in the area,
   The interference processing unit of the second base station apparatus gives priority to data transmission to one of the terminal apparatuses over other terminals at different times or toward the space between the terminal apparatuses. 5. The communication system according to any one of 4.

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