WO2016121200A1

WO2016121200A1 - Device

Info

Publication number: WO2016121200A1
Application number: PCT/JP2015/082312
Authority: WO
Inventors: 高野　裕昭
Original assignee: ソニー株式会社
Priority date: 2015-01-29
Filing date: 2015-11-17
Publication date: 2016-08-04

Abstract

[Problem] To make it possible to more appropriately ascertain the state of interference of directional beams. [Solution] Provided is a device comprising: an acquisition unit that acquires a channel that is inferred from a reference signal for measuring channel quality, and a plurality of precoding matrices corresponding to each of a plurality of directional beams; and a control unit that calculates the interference for each of the abovementioned plurality of directional beams, on the basis of the abovementioned channels and the abovementioned plurality of precoding matrices.

Description

apparatus

The present disclosure relates to an apparatus and a method.

Currently, in 3GPP (Third Generation Partnership Project), various technologies for improving the capacity of cellular systems are being studied in order to accommodate explosively increasing traffic. It is said that a capacity about 1000 times the current capacity will be required in the future. With technologies such as MU-MIMO (Multi-User Multiple-Input Multiple-Output) and CoMP (Coordinated Multipoint), the capacity of the cellular system is considered to increase only several times. Therefore, an innovative method is required.

For example, as a method for significantly increasing the capacity of the cellular system, it is conceivable that the base station performs beam forming using a directional antenna including a large number of antenna elements (for example, about 100 antenna elements). . Such a technique is a form of a technique called large-scale MIMO or massive MIMO. According to such beam forming, the half width of the beam becomes narrow. That is, a sharp beam is formed. Further, by arranging the multiple antenna elements on a plane, it is possible to form a beam in a desired three-dimensional direction.

For example, Patent Documents 1 to 3 disclose techniques applied when a directional beam in a three-dimensional direction is used.

JP 2014-204305 A JP 2014-53811 A JP 2014-64294 A

Usually, CSI-RS is transmitted without beamforming. For example, CSI-RS is not transmitted by a directional beam but transmitted by a non-directional radio wave. However, for example, when large-scale MIMO beamforming is performed and a data signal is transmitted by a sharp directional beam, the amount of interference calculated from CSI-RS transmitted by an omnidirectional radio wave and directivity The actual amount of interference of the beam can deviate. As a result, even if a large directional beam interference actually occurs, the occurrence of the interference may be missed.

Therefore, it is desirable to provide a mechanism that makes it possible to know the state of directional beam interference more appropriately.

According to the present disclosure, an acquisition unit that acquires a channel estimated from a reference signal for channel quality measurement, and a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the channel and the plurality of precodings There is provided an apparatus comprising: a control unit that calculates an interference amount of each of the plurality of directional beams based on a matrix.

Also, according to the present disclosure, there is provided an apparatus including an acquisition unit that acquires information indicating a configuration of a reference signal for channel quality measurement, and a control unit that notifies the terminal device of the configuration. The acquisition unit acquires a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the information indicating the plurality of precoding matrices being a part of all defined precoding matrices. Then, the control unit notifies the terminal device of the plurality of precoding matrices in association with the configuration.

Further, according to the present disclosure, an acquisition unit that acquires power increase information related to an increase in transmission power of a reference signal for channel quality measurement transmitted by a neighboring base station, and the reference signal using the power increase information And a control unit that performs control for correcting the amount of interference calculated from the above.

As described above, according to the present disclosure, it is possible to know the state of interference of a directional beam more appropriately. The above effects are not necessarily limited, and any of the effects shown in the present specification or other effects that can be grasped from the present specification are exhibited together with or in place of the above effects. May be.

It is explanatory drawing for demonstrating the weight set for the beam forming of large scale MIMO. It is explanatory drawing for demonstrating an example of the case where the beam forming of large scale MIMO is performed. It is explanatory drawing for demonstrating the relationship between multiplication of a weight coefficient and insertion of a reference signal. It is explanatory drawing for demonstrating the relationship between the multiplication of the weighting coefficient in a new approach, and insertion of a reference signal. It is explanatory drawing for demonstrating an example of the environment where a directional beam does not reflect. It is explanatory drawing for demonstrating an example of the environment where a directional beam reflects. It is explanatory drawing for demonstrating an example of the interference between the directional beams of a different cell. 2 is an explanatory diagram illustrating an example of a schematic configuration of a system according to an embodiment of the present disclosure. FIG. An example of the configuration of the base station according to the embodiment will be described. It is a block diagram which shows an example of a structure of the terminal device which concerns on the same embodiment. It is a sequence diagram which shows an example of the schematic flow of the process which concerns on 1st Embodiment. It is explanatory drawing for demonstrating the 1st example of the some precoding matrix which concerns on the modification of 1st Embodiment. It is explanatory drawing for demonstrating the 2nd example of the some precoding matrix which concerns on the modification of 1st Embodiment. It is a sequence diagram which shows an example of the schematic flow of the process which concerns on the modification of 1st Embodiment. It is a sequence diagram which shows an example of the schematic flow of the process which concerns on 2nd Embodiment. It is a sequence diagram which shows an example of the schematic flow of the process which concerns on the 1st modification of 2nd Embodiment. It is explanatory drawing for demonstrating an example of the increase in the transmission power of the reference signal for channel quality measurement. It is a sequence diagram which shows the 1st example of the schematic flow of the process which concerns on 3rd Embodiment. It is a sequence diagram which shows the 2nd example of the schematic flow of the process which concerns on 3rd Embodiment. It is a sequence diagram which shows the 3rd example of the schematic flow of the process which concerns on 3rd Embodiment. It is explanatory drawing for demonstrating an example of the relationship between the radio | wireless resource by which CSI-RS is transmitted, and the reception power of the said CSI-RS. It is a block diagram which shows the 1st example of schematic structure of eNB. It is a block diagram which shows the 2nd example of schematic structure of eNB. It is a block diagram which shows an example of a schematic structure of a smart phone. It is a block diagram which shows an example of a schematic structure of a car navigation apparatus.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

The description will be made in the following order.
1. 1. Introduction 1.1. Related technology 1.2. 1. Considerations related to this embodiment 2. Schematic configuration of system Configuration of each device 3.1. Configuration of base station 3.2. 3. Configuration of terminal device First embodiment 4.1. Technical issues 4.2. Technical features 4.3. Flow of processing 4.4. Modification 5 Second Embodiment 5.1. Technical issues 5.2. Technical features 5.3. Flow of processing 5.4. First modified example 5.5. Second modified example 6. Third Embodiment 6.1. Technical issues 6.2. Technical features 6.3. Flow of processing 6.4. Modification 7 Application example 7.1. Application examples related to base stations 7.2. 7. Application examples related to terminal devices Summary

<< 1. Introduction >>
First, with reference to FIG. 1 to FIG. 7, a technique related to the embodiment of the present disclosure and considerations related to the embodiment will be described.

<1.1. Related Technology>
With reference to FIGS. 1 to 4, beam forming and measurement will be described as techniques related to the embodiment of the present disclosure.

(1) Beam forming (a) Necessity of large-scale MIMO Currently, 3GPP is examining various technologies for improving the capacity of a cellular system in order to accommodate explosively increasing traffic. It is said that a capacity about 1000 times the current capacity will be required in the future. In technologies such as MU-MIMO and CoMP, the capacity of the cellular system is considered to increase only about several times. Therefore, an innovative method is required.

In Release 10 of 3GPP, it is standardized that eNodeB is equipped with 8 antennas. Therefore, according to the antenna, 8-layer MIMO can be realized in the case of SU-MIMO (Single-User Multi-Input Multiple-Input Multiple-Output). 8-layer MIMO is a technique for spatially multiplexing eight independent streams. In addition, two layers of MU-MIMO can be realized for four users.

In UE (User Equipment), it is difficult to increase the antenna elements of the UE antenna due to the small space for antenna arrangement and the limited processing capability of the UE. However, with recent advances in antenna mounting technology, it has become impossible to arrange a directional antenna including about 100 antenna elements in an eNodeB.

For example, as a method for significantly increasing the capacity of the cellular system, it is conceivable that the base station performs beam forming using a directional antenna including a large number of antenna elements (for example, about 100 antenna elements). . Such a technique is one form of a technique called large-scale MIMO or massive MIMO. According to such beam forming, the half width of the beam becomes narrow. That is, a sharp beam is formed. Further, by arranging the multiple antenna elements on a plane, it is possible to form a beam in a desired three-dimensional direction. For example, it has been proposed to transmit a signal to a terminal device existing at the position by forming a beam directed to a position higher than the base station (for example, an upper floor of a high-rise building).

In typical beam forming, it is possible to change the beam direction in the horizontal direction. Therefore, it can be said that the typical beam forming is two-dimensional beam forming. On the other hand, in large-scale MIMO (or massive MIMO) beamforming, the beam direction can be changed in the vertical direction in addition to the horizontal direction. Therefore, it can be said that large-scale MIMO beamforming is three-dimensional beamforming.

Note that since the number of antennas increases, the number of users in MU-MIMO can be increased. Such a technique is another form of a technique called large scale MIMO or massive MIMO. In addition, when the number of antennas of the UE is two, the number of spatially independent streams for one UE is two, and therefore, MU-MIMO rather than increasing the number of streams for one UE. It is more reasonable to increase the number of users.

(B) Weight set A weight set for beam forming (that is, a set of weight coefficients for a plurality of antenna elements) is expressed as a complex number. Hereinafter, an example of a weight set for beam forming of large scale MIMO will be described with reference to FIG.

FIG. 1 is an explanatory diagram for describing a weight set for large-scale MIMO beamforming. Referring to FIG. 1, antenna elements arranged in a lattice shape are shown. Also shown are two axes x, y orthogonal to the plane on which the antenna element is arranged, and one axis z orthogonal to the plane. Here, the direction of the beam to be formed is represented by, for example, an angle phi (Greek letter) and an angle theta (Greek letter). The angle phi (Greek letter) is an angle formed between the x-axis component and the xy plane component in the beam direction. The angle theta (Greek letter) is an angle formed by the beam direction and the z axis. In this case, for example, the weighting factor V _{m, n} of the antenna element arranged m-th in the x-axis direction and n-th arranged in the y-axis direction can be expressed as follows.

f is the frequency and c is the speed of light. J is an imaginary unit in a complex number. D _x is the distance between the antenna elements in the x-axis direction, and _dy is the distance between the antenna elements in the y-axis direction. The coordinates of the antenna element are expressed as follows.

A weight set for typical beam forming (two-dimensional beam forming) includes a weight set for obtaining directivity in the horizontal direction and a weight set for phase adjustment of dual layer MIMO (that is, 2 corresponding to different polarizations). And a weight set for phase adjustment between two antenna sub-arrays). On the other hand, the large-scale MIMO beamforming (three-dimensional beamforming) weight set includes a first weight set for obtaining directivity in the horizontal direction and a second weight set for obtaining directivity in the vertical direction. And a third weight set for phase adjustment of dual layer MIMO.

(C) Change in environment due to large-scale MIMO beamforming When large-scale MIMO beamforming is performed, the gain reaches 10 dB or more. In the cellular system that employs the beam forming, the radio wave environment can change more drastically than the conventional cellular system.

(D) Case where large-scale MIMO beamforming is performed For example, a base station in an urban area may form a beam toward a high-rise building. Even in the suburbs, it is conceivable that a small cell base station forms a beam toward an area around the base station. It is highly likely that a macrocell base station in the suburbs does not perform large-scale MIMO beamforming.

FIG. 2 is an explanatory diagram for explaining an example of a case where large-scale MIMO beamforming is performed. Referring to FIG. 2, a base station 71 and a high-rise building 73 are shown. For example, the base station 71 forms a directional beam 79 to the high-rise building 73 in addition to the

directional beams

75 and 77 to the ground.

(2) Measurement
The measurement includes measurement for selecting a cell and measurement for feeding back CQI (Channel Quality Indicator) and the like after connection. The latter measurement is required to be performed in a shorter time. In addition to measuring the quality of the serving cell, the measurement of the amount of interference from neighboring cells is also considered to be a kind of CQI measurement.

(A) CQI measurement CRS (Cell-specific Reference Signal) may be used for CQI measurement, but CSI-RS (Channel State Information Reference Signal) is mainly used for CQI measurement after Release 10. The

CSI-RS is transmitted without beamforming, similar to CRS. That is, the CSI-RS is transmitted without being multiplied by a weight set for beamforming, as in the case of CRS. Hereinafter, a specific example of this point will be described with reference to FIG.

FIG. 3 is an explanatory diagram for explaining the relationship between weighting coefficient multiplication and reference signal insertion. Referring to FIG. 3, the transmission signal 82 corresponding to each antenna element 81 is complex-multiplied by a weight coefficient 83 in a multiplier 84. Then, a transmission signal 82 obtained by complex multiplication of the weighting coefficient 83 is transmitted from the antenna element 81. Further, the DR-MS 85 is inserted before the multiplier 84, and the multiplier 84 multiplies the weight coefficient 83 by a complex multiplication. Then, the DR-MS 85 obtained by complex multiplication of the weight coefficient 83 is transmitted from the antenna element 81. On the other hand, the CSI-RS 86 (and CRS) is inserted after the multiplier 84. The CSI-RS 86 (and CRS) is transmitted from the antenna element 81 without being multiplied by the weighting coefficient 83.

As described above, since CSI-RS is transmitted without beamforming, when measurement is performed on CSI-RS, pure channel H (or channel response H) that is not affected by beamforming is used. ) Is estimated. This channel H is used to feed back RI (Rank Indicator), PMI (Precoding Matrix Indicator), and CQI (Channel Quality Indicator). Note that only CQI is fed back depending on the transmission mode. Also, the amount of interference can be fed back.

(B) CSI-RS
Until Release 12, as described above, the CSI-RS is transmitted without beamforming. Therefore, when the measurement for CSI-RS is performed, a raw channel H that is not affected by beamforming is estimated. The For this reason, CSI-RS worked in the same way as CRS.

Since CRS is used for cell selection and synchronization, the transmission frequency of CRS is higher than the transmission frequency of CSI-RS. That is, the CSI-RS cycle is longer than the CRS cycle.

For a large scale MIMO environment, a first approach for transmitting CSI-RS without beamforming and a second approach for transmitting CSI-RS with beamforming (ie, transmitting CSI-RS with a directional beam) There can be an approach. It can be said that the first approach is a conventional approach, and the second approach is a new approach. Hereinafter, with reference to FIG. 4, the relationship between weight coefficient multiplication and reference signal insertion in the new approach (second approach) will be described.

FIG. 4 is an explanatory diagram for explaining the relationship between weighting factor multiplication and reference signal insertion in a new approach. Referring to FIG. 4, transmission signal 92 corresponding to each antenna element 91 is complex-multiplied by weighting factor 93 in multiplier 94. Then, a transmission signal 92 obtained by complex multiplication of the weight coefficient 93 is transmitted from the antenna element 91. The DR-MS 95 is inserted in front of the multiplier 94, and the multiplier 94 multiplies the weight coefficient 93 in a complex manner. Then, the DR-MS 95 obtained by complex multiplication of the weight coefficient 93 is transmitted from the antenna element 91. Further, CSI-RS 96 is inserted before multiplier 94, and weighting factor 93 is complex-multiplied by multiplier 94. Then, CSI-RS 96 obtained by complex multiplication of the weight coefficient 93 is transmitted from the antenna element 91. On the other hand, the CRS 97 (and normal CSI-RS) is inserted after the multiplier 94. The CRS 97 (and normal CSI-RS) is transmitted from the antenna element 91 without being multiplied by the weight coefficient 93.

<1.2. Considerations Related to Embodiments of the Present Disclosure>
Considerations associated with embodiments of the present disclosure will be described with reference to FIGS.

(1) Interference between directional beams (a) Interference within a cell In an environment where a directional beam formed by an eNB is not reflected, no interference occurs between directional beams formed by the eNB. On the other hand, in an environment where a directional beam formed by an eNB is reflected, interference may occur between the directional beams formed by the eNB. Hereinafter, a specific example of this point will be described with reference to FIGS. 5 and 6.

FIG. 5 is an explanatory diagram for explaining an example of an environment where a directional beam is not reflected. Referring to FIG. 5, the eNB 11 and the

UEs

21, 23, and 25 are shown. For example, the eNB 11 forms a directional beam 31 directed to the UE 21, a directional beam 33 directed to the UE 23, and a directional beam 35 directed to the UE 25. In this example, the

directional beams

31, 33 and 35 are not reflected, and no interference occurs between the

directional beams

31, 33 and 35.

FIG. 6 is an explanatory diagram for explaining an example of an environment in which a directional beam is reflected. Referring to FIG. 6, the eNB 11 and the

UEs

21, 23, and 25 are shown. In addition,

obstacles

41 and 43 are shown. For example, the

obstacles

41 and 43 are buildings. For example, the eNB 11 forms a directional beam 31 directed to the UE 21, a directional beam 33 directed to the UE 23, and a directional beam 35 directed to the UE 25. In this example, the directional beam 35 is reflected by the

obstacles

41 and 43 and reaches the UE 23. For this reason, interference occurs between the directional beam 33 and the directional beam 35.

(B) Interference between cells Not only interference between directional beams in a cell but also interference between directional beams in different cells may occur. Hereinafter, a specific example of this point will be described with reference to FIG.

FIG. 7 is an explanatory diagram for explaining an example of interference between directional beams of different cells. Referring to FIG. 7, eNBs 11 and 13 and

UEs

21, 23, and 25 are shown. For example, the eNB 11 forms a directional beam 31 directed to the UE 21, a directional beam 33 directed to the UE 23, and a directional beam 35 directed to the UE 25. Further, the eNB 13 forms a directional beam 37, and the directional beam 37 reaches the UE 25. Therefore, interference occurs between the directional beam 35 formed by the eNB 11 and the directional beam 37 formed by the eNB 13.

(C) Deterioration of reception quality As described above, when interference of directional beams within a cell and / or directional beam interference between cells occurs, reception quality of the UE decreases, and as a result, the system Throughput can be reduced.

Interference may occur between two directional beams, or interference may occur between three or more directional beams. The number of directional beams in which interference occurs depends on the UE. For example, referring again to FIG. 6, interference is not generated in each of the

UEs

21 and 25, but interference is generated between the three directional beams in the UE 23. That is, the state of interference differs depending on the location.

A single operating band has a high frequency band (component carrier) and a low frequency band (component carrier), but the interference situation is generally the same in each frequency band. I can say that.

(2) Required Response When only a desired directional beam reaches the UE, the UE can obtain good reception quality. On the other hand, when not only a desired directional beam but also other directional beams reach the UE, reception quality at the UE may deteriorate.

In order to suppress such interference, it is important that the eNB first grasps the state of directional beam interference. Since the eNB cannot know the situation of such directional beam interference itself, it is conceivable that the UE reports the situation of directional beam interference to the eNB. For example, it is conceivable to calculate the interference amount of a directional beam other than the desired directional beam from the CSI-RS. It is also conceivable to use a CSI feedback procedure.

Normally, there are two types of channel quality measurement. One is RRM (Radio Resource Management) measurement such as RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) measurement, and the other is RI, CQI, PMI, etc. included in CSI. It is a measurement to determine. The former is mainly performed for cell selection and is performed by both the RRC idle mode UE and the RRC connected mode UE. On the other hand, the latter is performed in order to know the interference situation and is performed by the UE in the RRC connection mode.

(3) CSI-RS
CSI-RS is defined in Release 10. A normal CSI-RS is also called a non zero power CSI-RS. Since the purpose of CSI-RS is to acquire a raw channel, CSI-RS is transmitted without beamforming.

On the other hand, Zero power CSI-RS is also specified. Zero power CSI-RS is defined to facilitate observation of relatively weak signals from other eNBs. In the radio resource (resource element) for zero power CSI-RS, since the eNB does not transmit a signal, the UE can receive signals from other eNBs using the radio resource.

The CSI-RS cycle is variable between 5 ms and 80 ms. In addition, 40 radio resources are prepared in one subframe as candidates for radio resources for transmitting CSI-RS.

Conventionally, only one CSI-RS is configured in one cell. On the other hand, a plurality of zero power CSI-RSs can be set in one cell. Therefore, if the serving eNB of the UE sets the zero power CSI-RS in accordance with the setting of the CSI-RS of the neighboring eNB, the UE is not affected by the signal of the serving eNB, and the neighboring eNB Measurements of CSI-RS can be performed.

Note that the CSI-RS configuration is specific to a cell. The configuration can be communicated to the UE by higher layer signaling.

<< 2. Schematic configuration of system >>
Next, a schematic configuration of the system 1 according to the embodiment of the present disclosure will be described with reference to FIG. FIG. 8 is an explanatory diagram illustrating an example of a schematic configuration of the system 1 according to the embodiment of the present disclosure. Referring to FIG. 8, the system 1 includes a base station 100, a terminal device 200, and a peripheral base station 300. The system 1 is, for example, a system that complies with LTE, LTE-Advanced, or a communication standard based on these.

(Base station 100)
The base station 100 performs wireless communication with the terminal device 200. For example, the base station 100 performs wireless communication with the terminal device 200 located in the cell 101 of the base station 100.

In particular, in the embodiment of the present disclosure, the base station 100 performs beam forming. For example, the beam forming is large-scale MIMO beam forming. The beam forming may also be referred to as massive MIMO beam forming, free dimension MIMO beam forming, or three-dimensional beam forming. Specifically, for example, the base station 100 includes a directional antenna that can be used for large-scale MIMO, and performs large-scale MIMO beamforming by multiplying a transmission signal by a weight set for the directional antenna. .

Furthermore, particularly in the embodiment of the present disclosure, the base station 100 transmits a reference signal for channel quality measurement without beamforming. That is, the base station 100 transmits the reference signal without multiplying the reference signal by the weight set. For example, the reference signal is CSI-RS.

(Terminal device 200)
The terminal device 200 performs wireless communication with the base station. For example, when the terminal device 200 is located in the cell 101 of the base station 100, the terminal device 200 performs wireless communication with the base station 100. For example, when the base station 200 is located in the cell 301 of the peripheral base station 300, the base station 200 performs wireless communication with the peripheral base station 300.

For example, the terminal device 200 is connected to the base station 100. That is, the base station 100 is a serving base station for the terminal device 200, and the cell 101 is a serving cell for the terminal device 200.

(Nearby base station 300)
A neighbor base station 300 is a neighbor base station of the base station 100. For example, the peripheral base station 300 has the same configuration as the base station 100 and performs the same operation as the base station 100.

FIG. 8 shows only one peripheral base station 300, but the system 1 may include a plurality of peripheral base stations 300.

Note that both the base station 100 and the peripheral base station 300 may be macro cell base stations. Alternatively, both the base station 100 and the peripheral base station 300 may be small cell base stations. Alternatively, one of the base station 100 and the neighboring base station 300 may be a macro cell base station, and the other of the base station 100 and the neighboring base station 300 may be a small cell base station.

<< 3. Configuration of each device >>
Next, examples of configurations of the base station 100 and the terminal device 200 will be described with reference to FIGS. 9 and 10.

<3.1. Base station configuration>
First, an example of a configuration of the base station 100 according to the embodiment of the present disclosure will be described with reference to FIG. FIG. 9 is a block diagram illustrating an exemplary configuration of the base station 100 according to the embodiment of the present disclosure. Referring to FIG. 9, the base station 100 includes an antenna unit 110, a wireless communication unit 120, a network communication unit 130, a storage unit 140, and a processing unit 150.

(Antenna unit 110)
The antenna unit 110 radiates the signal output from the wireless communication unit 120 to the space as a radio wave. Further, the antenna unit 110 converts radio waves in space into a signal and outputs the signal to the wireless communication unit 120.

For example, the antenna unit 110 includes a directional antenna. For example, the directional antenna is a directional antenna that can be used for large scale MIMO.

(Wireless communication unit 120)
The wireless communication unit 120 transmits and receives signals. For example, the radio communication unit 120 transmits a downlink signal to the terminal device 200 and receives an uplink signal from the terminal device 200.

(Network communication unit 130)
The network communication unit 130 transmits and receives information. For example, the network communication unit 130 transmits information to other nodes and receives information from other nodes. For example, the other nodes include other base stations (for example, neighboring base stations 300) and core network nodes.

(Storage unit 140)
The storage unit 140 stores a program and data for the operation of the base station 100.

(Processing unit 150)
The processing unit 150 provides various functions of the base station 100. The processing unit 150 includes an information acquisition unit 151 and a control unit 153. The processing unit 150 may further include other components other than these components. That is, the processing unit 150 can perform operations other than the operations of these components.

Specific operations of the information acquisition unit 151 and the control unit 153 will be described in detail later.

<3.2. Configuration of terminal device>
Next, an example of a configuration of the terminal device 200 according to the embodiment of the present disclosure will be described with reference to FIG. FIG. 10 is a block diagram illustrating an example of a configuration of the terminal device 200 according to the embodiment of the present disclosure. Referring to FIG. 10, the terminal device 200 includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a processing unit 240.

(Antenna unit 210)
The antenna unit 210 radiates the signal output from the wireless communication unit 220 to the space as a radio wave. Further, the antenna unit 210 converts a radio wave in the space into a signal and outputs the signal to the wireless communication unit 220.

(Wireless communication unit 220)
The wireless communication unit 220 transmits and receives signals. For example, the radio communication unit 220 receives a downlink signal from the base station 100 and transmits an uplink signal to the base station 100.

(Storage unit 230)
The storage unit 230 stores a program and data for the operation of the terminal device 200.

(Processing unit 240)
The processing unit 240 provides various functions of the terminal device 200. The processing unit 240 includes an information acquisition unit 241 and a control unit 243. Note that the processing unit 240 may further include other components other than these components. That is, the processing unit 240 can perform operations other than the operations of these components.

Specific operations of the information acquisition unit 241 and the control unit 243 will be described later in detail.

<< 4. First Embodiment >>
Subsequently, a first embodiment of the present disclosure will be described with reference to FIGS. 11 to 14.

<4.1. Technical issues>
First, a technical problem according to the first embodiment will be described.

<4.2. Technical features>
Next, technical features according to the first embodiment will be described.

In the first embodiment, the terminal device 200 (information acquisition unit 241) acquires a channel estimated from a channel quality measurement reference signal and a plurality of precoding matrices respectively corresponding to a plurality of directional beams. . Then, the terminal device 200 (the control unit 243) calculates the interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices.

(1) Reference signal (a) Example of reference signal For example, the reference signal is a channel state information reference signal (CSI-RS).

(B) Subject of transmission For example, the reference signal is a signal transmitted by the peripheral base station 300. As described above, the peripheral base station 300 is a peripheral base station of the serving base station of the terminal device 200 (that is, the base station 100).

(C) Notification of Configuration For example, the base station 100 (information acquisition unit 151) acquires information indicating the configuration of the reference signal. Then, the base station 100 (control unit 153) notifies the terminal device 200 of the configuration.

(C-1) Contents of Configuration For example, the configuration includes at least one of a radio resource used for transmitting the reference signal and a sequence of the reference signal. For example, the configuration includes both the radio resource and the sequence. For example, the radio resource is one or more resource elements.

Note that the above reference signal transmitted by the peripheral base station 300 and another reference signal for channel quality measurement transmitted by another peripheral base station 300 (not shown in FIG. 8) are in the same radio resource. Even if transmitted, the terminal device 200 can detect the reference signal by performing reception processing based on the sequence using a correlator. That is, code division is possible. For example, different sequences are used between base stations.

(C-2) Notification to the base station 100 by the peripheral base station 300 For example, the peripheral base station 300 notifies the base station 100 of the configuration (of the reference signal transmitted by the peripheral base station 300). For example, the peripheral base station 300 transmits information indicating the configuration via an interface (for example, an X2 interface) between the peripheral base station 300 and the base station 100.

(C-3) Notification method-Zero power CSI-RS
For example, the base station 100 notifies the terminal device 200 of the configuration as a configuration of zero power CSI-RS.

-Signaling / system information For example, the base station 100 (the control unit 153) notifies the terminal device 200 of the configuration by individual signaling to the terminal device 200. That is, the base station 100 (control unit 153) generates a signaling message (for example, an RRC message) including information indicating the configuration. Then, the base station 100 transmits the signaling message to the terminal device 200.

Alternatively or additionally, the base station 100 (control unit 153) may notify the terminal device 200 of the configuration in the system information. That is, the base station 100 (control unit 153) may generate system information (for example, SIB (System Information Block)) including information indicating the configuration. Then, the base station 100 may transmit the system information.

(C-4) Notification of neighboring base station 300 For example, the base station 100 (control unit 153) notifies the terminal device 200 of the neighboring base station 300 that transmits the reference signal in association with the configuration.

More specifically, for example, the base station 100 (the control unit 153) generates a message including information indicating the configuration and identification information (for example, a cell ID) for identifying the neighboring base station 300. . Then, the base station 100 (the control unit 153) transmits the message to the terminal device 200.

Alternatively or additionally, the base station 100 (the control unit 153) may generate system information (for example, SIB) including information indicating the configuration and identification information for identifying the neighboring base station 300. Then, the base station 100 (the control unit 153) may transmit the system information.

As a result, for example, it is possible to calculate the amount of interference for each peripheral base station (that is, the amount of interference for each interference source), not the amount of interference from the entire surrounding base station (that is, the amount of interference from the entire interference source). become.

(2) Channel Estimation For example, the channel is a channel estimated by the terminal device 200. That is, the terminal device 200 estimates the channel from the reference signal. For example, channel H is estimated.

For example, the channel estimated by the terminal device 200 is stored in the storage unit 230. Thereafter, the terminal device 200 (information acquisition unit 241) acquires the channel from the storage unit 230.

Note that the above channel is, in other words, a channel matrix or a channel response.

(3) Calculation of interference amount As described above, in the first embodiment, the terminal device 200 (control unit 243) determines each of the plurality of directional beams based on the channel and the plurality of precoding matrices. The amount of interference is calculated.

For example, the terminal device 200 calculates the interference amount of each of the N directional beams based on the channel H and the N precoding matrices PM (i) (i = 0 to N−1).

More specifically, for example, the terminal device 200 multiplies the channel H by the precoding matrix PM (i) (from the right side), and uses the norm of the result of this multiplication as the interference of the directional beam i of the neighboring base station 300. Calculate as a quantity. That is, the terminal device 200 calculates the interference amount I (i) of the directional beam i of the neighboring base station 300 as follows.

By performing the calculation as described above for each precoding matrix PM (i) (i = 0 to N−1), the interference amount of each beam i (i = 0 to N−1) of the neighboring base station 300 is calculated. Is done.

The terminal device 200 can calculate the interference amount not only for one peripheral base station 300 but also for other peripheral base stations 300 (not shown in FIG. 8).

For example, the amount of interference is calculated as described above. Thereby, for example, it becomes possible to know the state of directional beam interference more appropriately. More specifically, for example, even if a channel quality measurement reference signal is not transmitted by a directional beam, the amount of interference of the directional beam can be virtually known. Further, since the reference signal is not transmitted by the directional beam, an increase in transmission load for the peripheral base station 300 and a measurement load for the terminal device 200 can be suppressed. Also, backward compatibility can be ensured.

Note that the plurality of precoding matrices are, for example, all the precoding matrices (defined in the standard). Further, the plurality of precoding matrices are stored in advance in the storage unit 230, and the terminal device 200 (information acquisition unit 241) acquires the plurality of precoding matrices from the storage unit 230.

(4) Report to Base Station 100 For example, the terminal device 200 (the control unit 243) reports information related to directional beam interference (hereinafter, “interference-related information”) to the base station 100.

As an example, the terminal device 200 (control unit 243) reports information indicating the amount of interference of the directional beam to the base station 100 as the interference related information. For example, the terminal device 200 (the control unit 243), as the interference-related information, identification information (for example, PMI) for identifying the directional beam and / or identification information for identifying the neighboring base station 300 (Eg, cell ID) is also reported to the base station 100.

The terminal device 200 (the control unit 243) may report information indicating the amount of interference of each of the plurality of directional beams to the base station 100, or one of the plurality of directional beams that is part of the plurality of directional beams. Information indicating the amount of interference of each of the above directional beams may be reported to the base station 100. The one or more directional beams may be directional beams having an interference amount larger than a threshold value.

Note that, for example, the base station 100 transmits the interference-related information reported by the terminal device 200 to the neighboring base station 300. Further, for example, the neighboring base station 300 makes a decision on the directional beam (for example, stop of the directional beam) based on the interference related information.

<4.3. Flow of processing>
Next, an example of processing according to the first embodiment will be described with reference to FIG. FIG. 11 is a sequence diagram illustrating an example of a schematic flow of processing according to the first embodiment.

The neighboring base station 300 notifies the base station 100 of the configuration of the reference signal for channel quality measurement transmitted by the neighboring base station 300 (hereinafter referred to as “RS configuration”) (S401).

The base station 100 notifies the terminal device 200 of the RS configuration (S403). In addition, the base station 100 notifies the terminal device 200 of the neighboring base station 300 in association with the RS configuration (S405). For example, the base station 100 transmits a message including information indicating the RS configuration and identification information (for example, a cell ID) for identifying the neighboring base station 300 to the terminal device 200 (S403, S405). .

The peripheral base station 300 transmits a reference signal for channel quality measurement (S407).

The terminal device 200 estimates a channel from the reference signal transmitted by the neighboring base station 300 (S409). Thereafter, the terminal device 200 acquires the channel and a plurality of precoding matrices respectively corresponding to the plurality of directional beams, and based on the channel and the plurality of precoding matrices, the terminal apparatus 200 Each interference amount is calculated (S411). And the terminal device 200 reports the interference relevant information regarding the interference of a directional beam to the base station 100 (S413).

The base station 100 transmits the interference-related information reported by the terminal device 200 to the neighboring base station 300 (S415). Then, the neighboring base station 300 makes a decision on the directional beam (for example, stop of the directional beam) based on the interference related information (S417).

<4.4. Modification>
Next, a modification according to the first embodiment will be described with reference to FIGS.

(1) Technical Problem As described above, for example, the plurality of precoding matrices are all precoding matrices (defined in the standard). However, if the interference amount of all directional beams is calculated based on all the precoding matrices, for example, the load for calculating the interference amount increases.

Therefore, it is desirable to provide a mechanism that makes it possible to reduce the load for calculating the interference amount of the directional beam.

(2) Technical features In the modification of the first embodiment, the plurality of precoding matrices are a part of all defined precoding matrices.

(A) Route of precoding matrix acquisition by base station 100 (a-1) First example For example, the neighboring base station 300 notifies the base station 100 of the plurality of precoding matrices. For example, the neighboring base station 300 notifies the base station 100 of the plurality of precoding matrices in association with the configuration of the reference signal.

More specifically, for example, the neighboring base station 300 generates a message including information indicating the configuration and information indicating the plurality of precoding matrices (for example, a plurality of PMIs). Then, the peripheral base station 300 transmits the message to the base station 100 via an interface (for example, an X2 interface) between the peripheral base station 300 and the base station 100.

Note that, for example, the plurality of precoding matrices notified from the neighboring base station 300 to the base station 100 are stored in the storage unit 140. Thereafter, the base station 100 (information acquisition unit 151) acquires the plurality of precoding matrices from the storage unit 140.

(A-2) Second Example The plurality of precoding matrices may be stored in advance in the base station 100 (storage unit 140). For example, the operator may store the plurality of precoding matrices in the base station 100 (storage unit 140). The base station 100 (information acquisition unit 151) may acquire the plurality of precoding matrices from the storage unit 140.

(B) Notification by base station The base station 100 (information acquisition unit 151) acquires the plurality of precoding matrices. Then, the base station 100 (the control unit 153) notifies the terminal device 200 of the plurality of precoding matrices in association with the configuration (of the reference signal).

For example, the base station 100 (the control unit 153), information indicating the configuration, identification information (for example, cell ID) for identifying the neighboring base station 300, and information indicating the plurality of precoding matrices (for example, , A plurality of PMI). Then, the base station 100 (the control unit 153) transmits the message to the terminal device 200.

Alternatively / further, the base station 100 (control unit 153) includes system information (information indicating the configuration, identification information for identifying the neighboring base station 300, and information indicating the plurality of precoding matrices). For example, SIB) may be generated. Then, the base station 100 (the control unit 153) may transmit the system information.

(C) Multiple Precoding Matrix (c-1) Application Unit For example, the multiple precoding matrices are unique to the base station 100. That is, the plurality of precoding matrices are applied to all the terminal devices 200 connected to the base station 100.

Alternatively, the plurality of precoding matrices may be unique to the terminal device 200. That is, the plurality of precoding matrices may be applied to individual terminal apparatuses 200.

(C-2) Specific Example For example, the plurality of directional beams are directional beams with limited directivity in one of the horizontal direction and the vertical direction. That is, the plurality of precoding matrices are precoding matrices corresponding to a plurality of directional beams whose directivities in one of the horizontal direction and the vertical direction are limited. Hereinafter, a specific example of this point will be described with reference to FIGS.

FIG. 12 is an explanatory diagram for describing a first example of a plurality of precoding matrices according to a modification of the first embodiment. Referring to FIG. 12, a terminal device 200 and a peripheral base station 300 are shown. In addition, high-

rise buildings

45 and 47 are also shown. For example, when the neighboring base station 300 forms a high-angle directional beam in the vertical direction, the directional beam reaches the terminal device 200 located in the high-rise building 47 and causes interference. obtain. For example, the directional beam 51 is reflected by the high-rise building 45 and reaches the terminal device 200 located in the high-rise building 47. The directional beam 52 directly reaches the terminal device 200 located in the high-rise building 47. Further, when the peripheral base station 300 forms a directional beam having a low angle (for example, the directional beam 53) in the vertical direction, the directional beam is reflected on the ground and is reflected on the high-rise building 47. It may reach the terminal device 200 that is located and cause interference. Note that when the peripheral base station 300 forms a directional beam having a neutral angle in the vertical direction (for example, the directional beam 54), the directional beam may not be reflected (or reflected). ), The terminal device 200 located in the high-rise building 47 is not reached. That is, the directional beam does not cause interference. In such a case, for example, the base station 100 notifies the terminal device 200 of a plurality of precoding matrices corresponding to a plurality of directional beams whose directivities in the vertical direction are limited to high angles and low angles. Then, the terminal device 200 calculates the interference amounts of the plurality of directional beams based on the plurality of precoding matrices.

FIG. 13 is an explanatory diagram for describing a second example of a plurality of precoding matrices according to a modification of the first embodiment. Referring to FIG. 13, a base station 100, a terminal device 200, and a peripheral base station 300 are shown. In this example, the base station 100 and the terminal device 200 are located on the south side of the peripheral base station 300. Therefore, when the peripheral base station 300 forms a directional beam in the south direction in the horizontal direction (for example, the

directional beams

56, 57, 58, 59), the directional beam reaches the terminal device 200. obtain. In such a case, for example, the base station 100 notifies the terminal device 200 of a plurality of precoding matrices corresponding to a plurality of directional beams whose directivity in the horizontal direction is limited to the south direction. Then, the terminal device 200 calculates the interference amounts of the plurality of directional beams based on the plurality of precoding matrices.

As described above, in the modification of the first embodiment, the plurality of precoding matrices are a part of all defined precoding matrices. Thereby, for example, it becomes possible to further reduce the load for calculating the interference amount of the directional beam.

(3) Process Flow FIG. 14 is a sequence diagram illustrating an example of a schematic flow of a process according to a modification of the first embodiment.

The neighboring base station 300 notifies the base station 100 of the configuration (that is, RS configuration) of the reference signal for channel quality measurement transmitted by the neighboring base station 300 (S431). In addition, the neighboring base station 300 notifies the base station 100 of a plurality of precoding matrices (PMs) respectively corresponding to the plurality of directional beams in association with the RS configuration (S433). The plurality of precoding matrices are a part of all defined precoding matrices. For example, the neighboring base station 300 transmits a message including information indicating the RS configuration and information indicating the plurality of precoding matrices (for example, a plurality of PMIs) to the base station 100 (S431, S433). .

The base station 100 notifies the terminal device 200 of the RS configuration (S435). Also, the base station 100 notifies the terminal device 200 of the neighboring base station 300 in association with the RS configuration (S437). In addition, the base station 100 notifies the terminal device 200 of the plurality of precoding matrices in association with the RS configuration (S439). For example, the base station 100 includes information indicating the RS configuration, identification information for identifying the neighboring base station 300 (for example, a cell ID), and information indicating the plurality of precoding matrices (for example, a plurality of PMIs). ) Is transmitted to the terminal device 200 (S435, S437, S439).

The peripheral base station 300 transmits a reference signal for channel quality measurement (S441).

The terminal apparatus 200 estimates a channel from the reference signal transmitted by the neighboring base station 300 (S443). Thereafter, the terminal device 200 acquires the channel and the plurality of precoding matrices, and calculates the amount of interference of each of the plurality of directional beams based on the channel and the plurality of precoding matrices (S445). . And the terminal device 200 reports the interference relevant information regarding the interference of a directional beam to the base station 100 (S447).

The base station 100 transmits the interference-related information reported by the terminal device 200 to the neighboring base station 300 (S449). Then, the neighboring base station 300 makes a decision on the directional beam (for example, stop of the directional beam) based on the interference related information (S451).

<< 5. Second Embodiment >>
Subsequently, a second embodiment of the present disclosure will be described with reference to FIGS. 15 and 16.

<5.1. Technical issues>
The technical problem according to the second embodiment is the same as the technical problem according to the first embodiment. Therefore, the overlapping description is omitted here.

<5.2. Technical features>
Next, technical features according to the second embodiment will be described.

In the second embodiment, the base station 100 (information acquisition unit 151) acquires a channel estimated from a channel quality measurement reference signal and a plurality of precoding matrices respectively corresponding to a plurality of directional beams. . Then, base station 100 (control unit 153) calculates the amount of interference of each of the plurality of directional beams based on the channel and the plurality of precoding matrices.

(1) Reference Signal Regarding the reference signal, there is no particular difference between the first embodiment and the second embodiment. Therefore, the overlapping description is omitted here.

Particularly in the second embodiment, for example, the terminal device 200 reports the channel to the base station 100. Then, the channel is stored in the base station 100 (for example, the storage unit 140).

(3) Calculation of interference amount As described above, in the second embodiment, the base station 100 (control unit 153) determines each of the plurality of directional beams based on the channel and the plurality of precoding matrices. The amount of interference is calculated.

The description of the calculation of the interference amount is the same as that in the first embodiment except for the difference between the subjects (in the first embodiment, the subject is the terminal device 200 and in the second embodiment, the subject is the base station 100). There is no particular difference between the first embodiment and the second embodiment. Therefore, the overlapping description is omitted here.

Note that, for example, the base station 100 transmits interference-related information (information on directional beam interference) to the neighboring base stations 300. Further, for example, the neighboring base station 300 makes a decision on the directional beam (for example, stop of the directional beam) based on the interference related information.

<5.3. Flow of processing>
Next, an example of processing according to the second embodiment will be described with reference to FIG. FIG. 15 is a sequence diagram illustrating an example of a schematic flow of processing according to the second embodiment.

Here, the description of steps S461 to S467 and S475 to S477 in the example of FIG. 15 is not particularly different from the description of steps S401 to S407 and S415 to S417 in FIG. Therefore, the description which overlaps here is abbreviate | omitted and only step S469-S473 is demonstrated.

The terminal device 200 estimates the channel from the channel quality measurement reference signal transmitted by the neighboring base station 300 (S469). Then, the terminal device 200 reports the channel to the base station 100 (S471).

The base station 100 acquires the channel and a plurality of precoding matrices respectively corresponding to the plurality of directional beams, and based on the channel and the plurality of precoding matrices, each of the plurality of directional beams The amount of interference is calculated (S473).

<5.4. First Modification>
Next, a first modification according to the second embodiment will be described with reference to FIG.

(1) Technical problem The technical problem which concerns on the 1st modification of 2nd Embodiment is the same as the technical problem which concerns on the modification of 1st Embodiment. Therefore, the overlapping description is omitted here.

(2) Technical features In the first modification of the second embodiment, the plurality of precoding matrices are a part of all defined precoding matrices.

(A) Route of acquisition of precoding matrix by base station 100 The description of the route of acquisition of the precoding matrix by the base station 100 will be made for the modification of the first embodiment and the first modification of the second embodiment. There is no special case between the examples. Therefore, the overlapping description is omitted here.

(B) A plurality of precoding matrices The description of the plurality of precoding matrices is not particularly special between the modification of the first embodiment and the first modification of the second embodiment. . Therefore, the overlapping description is omitted here.

As described above, in the first modification of the second embodiment, the plurality of precoding matrices are a part of all defined precoding matrices. Thereby, for example, it becomes possible to further reduce the load for calculating the interference amount of the directional beam.

(3) Process Flow FIG. 16 is a sequence diagram illustrating an example of a schematic process flow according to the first modification of the second embodiment.

Here, the descriptions of steps S505 to S513 and S517 to S519 in the example of FIG. 16 are not particularly different from the descriptions of steps S463 to S471 and S475 to S477 in FIG. Therefore, duplicate description is omitted here, and only steps S501 to S503 and S515 will be described.

The peripheral base station 300 notifies the base station 100 of the configuration (that is, RS configuration) of the reference signal for channel quality measurement transmitted by the peripheral base station 300 (S501). In addition, the neighboring base station 300 notifies the base station 100 of a plurality of precoding matrices (PMs) respectively corresponding to the plurality of directional beams in association with the RS configuration (S503). For example, the neighboring base station 300 transmits a message including information indicating the RS configuration and information indicating the plurality of precoding matrices (for example, a plurality of PMIs) to the base station 100 (S501, S503). .

The base station 100 acquires a channel estimated by the terminal device 200 from the reference signal for channel quality measurement transmitted by the neighboring base station 300 and the plurality of precoding matrices. Then, the base station 100 calculates an interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices (S515).

<5.5. Second Modification>
Next, a second modification according to the second embodiment will be described.

As a second modification according to the second embodiment, not the base station 100 but the neighboring base station 300 acquires the channel and the plurality of precoding matrices, and based on the channel and the plurality of precoding matrices. Thus, the interference amount of each of the plurality of directional beams may be calculated.

Also, the base station 100 may notify the neighboring base station 300 of the channel reported by the terminal device 200.

<< 6. Third Embodiment >>
Subsequently, a third embodiment of the present disclosure will be described with reference to FIGS.

<6.1. Technical issues>
First, a technical problem according to the third embodiment will be described.

For example, when the peripheral base station transmits a data signal using a directional beam (for example, a large-scale MIMO directional beam), the peripheral base station is far away from the terminal device (and the serving base station). Even so, the reception power of the data signal in the terminal device may increase. That is, large interference may occur in the terminal device.

However, since CSI-RS is normally transmitted without beamforming, CSI-RS transmitted by the neighboring base station if the neighboring base station is far away from the terminal device (and serving base station). The received power in the terminal device can be very small. As a result, the terminal device may not be able to detect the CSI-RS and may not calculate the amount of interference. As a result, even if a large interference of the directional beam of the data signal occurs in the terminal device, the occurrence of the interference may be missed.

<6.2. Technical features>
Next, technical features according to the third embodiment will be described with reference to FIG.

The base station 100 (information acquisition unit 151) acquires power increase information related to an increase in transmission power of a channel quality measurement reference signal transmitted by the neighboring base station 300. Then, the base station 100 (the control unit 153) uses the power increase information to perform control for correcting the interference amount calculated from the reference signal.

(1) Reference signal In the description of the reference signal, there is no particular difference between the first embodiment and the third embodiment. Therefore, the overlapping description is omitted here.

(2) Calculation of interference amount For example, the terminal device 200 (control unit 243) calculates the interference amount from the reference signal transmitted by the neighboring base station 300.

More specifically, for example, as in the first embodiment, the terminal device 200 (the control unit 243) estimates a channel from the reference signal, and a plurality of channels respectively corresponding to the channel and a plurality of directional beams. The amount of interference of each of the plurality of directional beams is calculated based on the precoding matrix.

In addition, instead of the terminal device 200, the base station 100 (the control unit 153) may calculate the interference amount. More specifically, for example, the terminal device 200 reports the channel estimated from the reference signal to the base station 100, and the base station 100 determines the plurality of directivities based on the channel and the plurality of directional beams. The amount of interference of each beam may be calculated.

(3) Power increase information (a) Power increase For example, the peripheral base station 300 increases the transmission power of the reference signal. That is, for example, the peripheral base station 300 transmits the reference signal using a directional beam with higher power. Hereinafter, a specific example of this point will be described with reference to FIG.

FIG. 17 is an explanatory diagram for explaining an example of an increase in transmission power of a reference signal for channel quality measurement. Referring to FIG. 17, two resource blocks included in one subframe are shown. In this example, the neighboring base station 300 transmits CSI-RS with normal transmission power in the radio resource 61 (two resource elements) for channel quality measurement in the cell 301 of the neighboring base station 300. Also, the neighboring base station 300 has a transmission power that is larger by 5 dB than the normal transmission power in the radio resource 62 (two resource elements) in order to measure interference in a neighboring cell (a relatively nearby neighboring cell) of the cell 301. To transmit CSI-RS. Furthermore, the neighboring base station 300 transmits 10 dB larger than normal transmission power in the radio resource 63 (two resource elements) in order to measure interference in a neighboring cell (a relatively far neighboring cell) of the cell 301. To transmit CSI-RS.

Thus, for example, the neighboring base station 300 transmits the reference signal with the first transmission power (for example, normal transmission power) in the first radio resource (for example, the radio resource 61), and the second radio resource The reference signal is transmitted with a second transmission power larger than the first transmission power in the resource (for example, the radio resource 62). Furthermore, the neighboring base station 300 transmits the reference signal with a third transmission power larger than the second transmission power in a third radio resource (for example, the radio resource 63). Note that the base station 100 (the control unit 153) can also transmit a channel measurement reference signal, similarly to the neighboring base station 300.

For example, the neighboring base station 300 responds to a request from the base station 100 (for example, a request for configuration of a reference signal for measuring channel quality or a request for transmitting a reference signal for measuring channel quality with a large transmission power). In response, the transmission power of the reference signal is increased.

(B) Example of power increase information (b-1) First example As a first example, the power increase information indicates an increase in the transmission power of the reference signal.

For example, referring again to FIG. 17, the power increase information for the CSI-RS transmitted in the radio resource 62 indicates 5 dB, and the power increase information for the CSI-RS transmitted in the radio resource 63 indicates 10 dB.

(B-2) Second Example As a second example, the power increase information may be information (for example, a flag or an index) indicating that there is an increase in the transmission power of the reference signal. In this case, the increase amount of the transmission power of the reference signal for channel quality measurement may be one fixed amount (for example, 5 dB).

(C) Provision by Peripheral Base Station For example, the power increase information is information provided by the peripheral base station 300. That is, the neighboring base station 300 provides the power increase information to the base station 100.

As an example, the configuration of the reference signal includes an increase amount of transmission power of the reference signal (or presence / absence of increase of transmission power of the reference signal). In this case, the neighboring base station 300 provides the power increase information to the base station 100 by notifying the base station 100 of the configuration.

As another example, the configuration does not include the increase amount of the transmission power (and the presence or absence of the increase of the transmission power), and the neighboring base station 300 uses the power increase information independent of the information indicating the configuration. The base station 100 may be notified. For example, the neighboring base station 300 may transmit a message including the information indicating the configuration and the power increase information to the base station 100.

(4) Control (a) First example (a-1) Base station 100
As a first example, the control (that is, control for correcting the interference amount calculated from the reference signal) notifies the terminal device 200 that calculates the interference amount from the reference signal of the power increase information. It is. That is, the base station 100 (control unit 153) notifies the terminal device 200 of the power increase information.

As described above, for example, the configuration of the reference signal includes the amount of increase in the transmission power of the reference signal (or the presence or absence of increase in the transmission power of the reference signal). In this case, the base station 100 notifies the terminal device 200 of the power increase information by notifying the terminal device 200 of the configuration.

Alternatively, the configuration does not include the increase amount of the transmission power (and the presence or absence of the increase of the transmission power), and the base station 100 transmits the power increase information independent of the information indicating the configuration to the terminal device 200. You may be notified. For example, the base station 100 may transmit a message (or system information) including the information indicating the configuration and the power increase information to the terminal device 200.

(A-2) Terminal device 200
For example, the terminal device 200 (information acquisition unit 241) acquires the power increase information. Then, the terminal device 200 (information acquisition unit 241) corrects the interference amount calculated from the reference signal based on the power increase information. More specifically, for example, the terminal device 200 subtracts an increase in transmission power (for example, 5 dB or 10 dB) from the amount of interference.

(B) Second example (b-1) Base station 100
As a second example, the control may be to correct an interference amount calculated from the reference signal based on the power increase information. That is, the base station 100 (control unit 153) may correct the amount of interference calculated from the reference signal based on the power increase information. More specifically, the base station 100 may subtract an increase in transmission power (for example, 5 dB or 10 dB) from the amount of interference.

(B-2) Terminal device 200
The terminal device 200 may calculate the interference amount from the reference signal and report the interference amount to the base station 100.

Alternatively, the terminal device 200 may estimate a channel from the reference signal and report the channel to the base station 100. Then, the base station 100 may calculate the interference amount based on the channel (and a plurality of precoding matrices respectively corresponding to a plurality of directional beams).

Note that when the terminal device 200 reports the interference amount or the channel to the base station 100, the terminal device 200 may also report identification information (for example, a cell ID) for identifying the neighboring base station 300 to the base station 100. Good.

As described above, in the third embodiment, the transmission power of the reference signal is increased. Further, the interference amount calculated from the reference signal is corrected based on the power related information. Thereby, for example, it becomes possible to know the state of directional beam interference more appropriately. More specifically, for example, since the transmission power of the reference signal is increased, even if the neighboring base station 300 is far away from the terminal device 200 (and the base station 100), it is transmitted by the neighboring base station 300. The received power of the reference signal in the terminal device 200 increases to some extent. Therefore, the terminal device 200 can detect the reference signal. Further, since the interference amount is corrected, an appropriate interference amount can be obtained.

<6.3. Flow of processing>
Next, an example of processing according to the third embodiment will be described with reference to FIGS.

(1) First Example FIG. 18 is a sequence diagram illustrating a first example of a schematic flow of a process according to the third embodiment.

The base station 100 makes a request to the neighboring base station 300 (for example, a request for configuration of a reference signal for channel quality measurement or a request for transmission of a reference signal for channel quality measurement with a large transmission power) ( S531).

The neighboring base station 300 notifies the base station 100 of the configuration (that is, RS configuration) of the reference signal for channel quality measurement transmitted by the neighboring base station 300 (S533). For example, the RS configuration includes the amount of increase in the transmission power of the reference signal (or the presence or absence of the increase in the transmission power). Therefore, the neighboring base station 300 provides the base station 100 with power increase information (for example, information indicating the increase amount of the transmission power) related to an increase in the transmission power of the reference signal by the notification of the RS configuration.

The base station 100 notifies the terminal device 200 of the RS configuration (S535). The base station 100 notifies the terminal device 200 of the power increase information by the notification of the RS configuration. Further, the base station 100 notifies the terminal device 200 of the neighboring base station 300 in association with the RS configuration (S537). For example, the base station 100 transmits a message including information indicating the RS configuration and identification information (for example, a cell ID) for identifying the neighboring base station 300 to the terminal device 200 (S535, S537). .

The peripheral base station 300 transmits a reference signal for channel quality measurement (S539).

The terminal device 200 estimates a channel from the reference signal transmitted by the neighboring base station 300 (S541). Thereafter, the terminal device 200 calculates an interference amount based on the channel (S543), and corrects the interference amount based on the power increase information (for example, information indicating the increase amount of the transmission power) (S545). . For example, the terminal device 200 calculates the amount of interference of each of the plurality of directional beams based on the channel and a plurality of precoding matrices respectively corresponding to the plurality of directional beams, and includes the power increase information. Based on this, the interference amount is corrected.

The terminal device 200 reports interference-related information related to interference to the base station 100 (S547). The interference related information includes information indicating the amount of interference calculated and corrected by the terminal device 200. Further, for example, the interference related information includes the identification information (for example, cell ID) for identifying the neighboring base station 300 that has transmitted the reference signal.

The base station 100 transmits the interference-related information reported by the terminal device 200 to the neighboring base station 300 (S549). Then, the neighboring base station 300 makes a decision on the directional beam (for example, stop of the directional beam) based on the interference related information (S551).

(2) Second Example FIG. 19 is a sequence diagram illustrating a second example of a schematic flow of processing according to the third embodiment.

Here, the description of steps S561 to S563 in the example of FIG. 19 is not particularly different from the description of steps S531 to S533 in FIG. Therefore, the description which overlaps here is abbreviate | omitted and only step S565-S575 is demonstrated.

The base station 100 notifies the terminal device 200 of the configuration (that is, RS configuration) of the reference signal for channel quality measurement transmitted by the neighboring base station 300 (S565). In addition, the base station 100 notifies the terminal device 200 of the neighboring base station 300 in association with the RS configuration (S567). For example, the base station 100 transmits a message including information indicating the RS configuration and identification information (for example, a cell ID) for identifying the neighboring base station 300 to the terminal device 200 (S565, S567). . Note that the RS configuration notified from the base station 100 to the terminal device 200 may not include the amount of increase in the transmission power of the reference signal (or the presence or absence of the increase in the transmission power).

The terminal device 200 estimates a channel from the reference signal transmitted by the neighboring base station 300 (S571). Thereafter, the terminal device 200 calculates an interference amount based on the channel (S573). For example, the terminal device 200 calculates the amount of interference of each of the plurality of directional beams based on the channel and a plurality of precoding matrices respectively corresponding to the plurality of directional beams.

The terminal device 200 reports interference-related information regarding interference to the base station 100 (S575). The interference related information includes information indicating the amount of interference calculated by the terminal device 200. Further, for example, the interference related information includes the identification information (for example, cell ID) for identifying the neighboring base station 300 that has transmitted the reference signal.

The base station 300 corrects the interference amount calculated by the terminal device 200 based on power increase information (for example, information indicating the increase amount of the transmission power) related to an increase in the transmission power of the reference signal (S577). .

The base station 100 transmits interference related information regarding interference to the neighboring base station 300 (S579). For example, the interference related information includes information indicating the interference amount corrected by the base station 100. Then, the neighboring base station 300 makes a decision on the directional beam (for example, stop of the directional beam) based on the interference related information (S581).

(3) Third Example FIG. 20 is a sequence diagram illustrating a third example of a schematic flow of processing according to the third embodiment.

Here, the description of steps S601 to S607 and S619 to S621 in the example of FIG. 20 is not particularly different from the description of steps S561 to S567 and S579 to S581 of FIG. Therefore, the description which overlaps here is abbreviate | omitted and only step S609-S617 is demonstrated.

The peripheral base station 300 transmits a reference signal for channel quality measurement (S609).

The terminal device 200 estimates a channel from the reference signal transmitted by the neighboring base station 300 (S611). Then, the terminal device 200 reports the channel to the base station 100 (S613). For example, the terminal device 200 reports the identification information for identifying the neighboring base station 300 that has transmitted the reference signal in association with the channel to the base station 100.

The base station 100 calculates an interference amount based on the channel (S615), and the interference amount based on power increase information (for example, information indicating the increase amount of the transmission power) related to an increase in the transmission power of the reference signal. Is corrected (S617).

<6.4. Modification>
Next, a modification according to the third embodiment will be described with reference to FIG.

In the modification of the third embodiment, the base station 100 (the control unit 153) includes a first radio resource in which two or more neighboring base stations 300 transmit reference signals for channel quality measurement, and two The terminal apparatus 200 is notified of the second radio resource in which the reference signal for channel quality measurement is transmitted by the other peripheral base station 300 described above.

(1) Receiving power of reference signal In particular, in the modification of the third embodiment, the receiving power of the reference signal transmitted in the first radio resource in the terminal device 200 is transmitted in the second radio resource. The received power of the reference signal in the terminal device 200 is larger. That is, reference signals that bring about the same received power are transmitted using the same radio resource. Hereinafter, a specific example of this point will be described with reference to FIG.

FIG. 21 is an explanatory diagram for explaining an example of a relationship between a radio resource to which CSI-RS is transmitted and received power of the CSI-RS. Referring to FIG. 21, two resource blocks included in one subframe are shown. In this example, the base station 100 transmits CSI-RS in the radio resource 65 (two resource elements). Also, two or more neighboring base stations 300 transmit CSI-RS in the radio resource 66 (two resource elements), and two or more other neighboring base stations 300 send radio resources 67 (two resource elements). CSI-RS is transmitted. In particular, in the terminal device 200 whose serving base station is the base station 100, the reception power of the CSI-RS transmitted in the radio resource 66 is larger than the reception power of the CSI-RS transmitted in the radio resource 67. As described above, the two or more neighboring base stations 300 that transmit the CSI-RS with high received power transmit the CSI-RS in the radio resource 66 and transmit the CSI-RS with low received power. The other neighboring base stations 300 transmit the CSI-RS in the radio resource 67.

Thereby, for example, it is possible to avoid that CSI-RS with low reception power is not detected due to other CSI-RS with high reception power. Therefore, it becomes possible to know interference with a peripheral base station 300 (that is, a peripheral base station 300 that transmits a CSI-RS with low received power) far from the terminal device 200 (and the base station 300).

Note that, as described above, for example, the peripheral base station 300 may increase the transmission power of the reference signal for channel quality measurement, which allows flexible control of which peripheral base station 300 uses which radio resource. It may be possible to decide on.

(2) Notification method For example, the configuration of the reference signal transmitted by the two or more neighboring base stations 300 includes the first radio resource. Therefore, the base station 100 (control unit 153) notifies the terminal device 200 of the first radio resource by notifying the terminal device 200 of the configuration.

Similarly, for example, the configuration of the reference signal transmitted by the two or more other neighboring base stations 300 includes the second radio resource. Therefore, the base station 100 (the control unit 153) notifies the terminal device 200 of the second radio resource by notifying the terminal device 200 of the configuration.

The third embodiment has been described above. Note that the third embodiment may be combined with the first embodiment or the second embodiment. Specifically, the base station 100 (the information acquisition unit 151 and the control unit 153) according to the first embodiment or the second embodiment is the base station 100 (the information acquisition unit 151 and the control unit according to the third embodiment). The operation of the unit 153) may be performed similarly. Further, the terminal device 200 (information acquisition unit 241 and control unit 243) according to the first embodiment or the second embodiment is the same as the terminal device 200 (information acquisition unit 241 and control unit 243) according to the third embodiment. These operations may be performed in the same manner.

<< 7. Application example >>
The technology according to the present disclosure can be applied to various products. For example, the base station 100 may be realized as any type of eNB (evolved Node B) such as a macro eNB or a small eNB. The small eNB may be an eNB that covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB, or a home (femto) eNB. Instead, the base station 100 may be realized as another type of base station such as a NodeB or a BTS (Base Transceiver Station). Base station 100 may include a main body (also referred to as a base station apparatus) that controls radio communication, and one or more RRHs (Remote Radio Heads) that are arranged at locations different from the main body. Further, various types of terminals described later may operate as the base station 100 by temporarily or semi-permanently executing the base station function. Furthermore, at least some components of the base station 100 may be realized in a base station apparatus or a module for the base station apparatus.

Further, for example, the terminal device 200 is a smartphone, a tablet PC (Personal Computer), a notebook PC, a portable game terminal, a mobile terminal such as a portable / dongle type mobile router or a digital camera, or an in-vehicle terminal such as a car navigation device. It may be realized as. The terminal device 200 may be realized as a terminal (also referred to as an MTC (Machine Type Communication) terminal) that performs M2M (Machine To Machine) communication. Furthermore, at least a part of the components of the terminal device 200 may be realized in a module (for example, an integrated circuit module configured by one die) mounted on these terminals.

<7.1. Application examples for base stations>
(First application example)
FIG. 15 is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology according to the present disclosure may be applied. The eNB 800 includes one or more antennas 810 and a base station device 820. Each antenna 810 and the base station apparatus 820 can be connected to each other via an RF cable.

Each of the antennas 810 has a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission and reception of radio signals by the base station apparatus 820. The eNB 800 includes a plurality of antennas 810 as illustrated in FIG. 15, and the plurality of antennas 810 may respectively correspond to a plurality of frequency bands used by the eNB 800, for example. Although FIG. 15 illustrates an example in which the eNB 800 includes a plurality of antennas 810, the eNB 800 may include a single antenna 810.

The base station apparatus 820 includes a controller 821, a memory 822, a network interface 823, and a wireless communication interface 825.

The controller 821 may be a CPU or a DSP, for example, and operates various functions of the upper layer of the base station apparatus 820. For example, the controller 821 generates a data packet from the data in the signal processed by the wireless communication interface 825, and transfers the generated packet via the network interface 823. The controller 821 may generate a bundled packet by bundling data from a plurality of baseband processors, and may transfer the generated bundled packet. In addition, the controller 821 is a logic that executes control such as radio resource control, radio bearer control, mobility management, inflow control, or scheduling. May have a typical function. Moreover, the said control may be performed in cooperation with a surrounding eNB or a core network node. The memory 822 includes RAM and ROM, and stores programs executed by the controller 821 and various control data (for example, terminal list, transmission power data, scheduling data, and the like).

The network interface 823 is a communication interface for connecting the base station device 820 to the core network 824. The controller 821 may communicate with the core network node or other eNB via the network interface 823. In that case, the eNB 800 and the core network node or another eNB may be connected to each other by a logical interface (for example, an S1 interface or an X2 interface). The network interface 823 may be a wired communication interface or a wireless communication interface for wireless backhaul. When the network interface 823 is a wireless communication interface, the network interface 823 may use a frequency band higher than the frequency band used by the wireless communication interface 825 for wireless communication.

The wireless communication interface 825 supports any cellular communication scheme such as LTE (Long Term Evolution) or LTE-Advanced, and provides a wireless connection to terminals located in the cell of the eNB 800 via the antenna 810. The wireless communication interface 825 may typically include a baseband (BB) processor 826, an RF circuit 827, and the like. The BB processor 826 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and each layer (for example, L1, MAC (Medium Access Control), RLC (Radio Link Control), and PDCP). Various signal processing of (Packet Data Convergence Protocol) is executed. The BB processor 826 may have some or all of the logical functions described above instead of the controller 821. The BB processor 826 may be a module that includes a memory that stores a communication control program, a processor that executes the program, and related circuits. The function of the BB processor 826 may be changed by updating the program. Good. Further, the module may be a card or a blade inserted into a slot of the base station apparatus 820, or a chip mounted on the card or the blade. On the other hand, the RF circuit 827 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a radio signal via the antenna 810.

The wireless communication interface 825 includes a plurality of BB processors 826 as illustrated in FIG. 15, and the plurality of BB processors 826 may respectively correspond to a plurality of frequency bands used by the eNB 800, for example. Further, the wireless communication interface 825 includes a plurality of RF circuits 827 as illustrated in FIG. 15, and the plurality of RF circuits 827 may respectively correspond to a plurality of antenna elements, for example. 15 illustrates an example in which the wireless communication interface 825 includes a plurality of BB processors 826 and a plurality of RF circuits 827, the wireless communication interface 825 includes a single BB processor 826 or a single RF circuit 827. But you can.

In the eNB 800 illustrated in FIG. 15, the information acquisition unit 151 and the control unit 153 described with reference to FIG. 8 may be implemented in the wireless communication interface 825. Alternatively, at least some of these components may be implemented in the controller 821. As an example, the eNB 800 includes a module including a part (for example, the BB processor 826) or all of the wireless communication interface 825 and / or the controller 821, and the information acquisition unit 151 and the control unit 153 are mounted in the module. Also good. In this case, the module stores a program for causing the processor to function as the information acquisition unit 151 and the control unit 153 (in other words, a program for causing the processor to execute operations of the information acquisition unit 151 and the control unit 153). The program may be executed. As another example, a program for causing a processor to function as the information acquisition unit 151 and the control unit 153 is installed in the eNB 800, and the wireless communication interface 825 (for example, the BB processor 826) and / or the controller 821 executes the program. Also good. As described above, the eNB 800, the base station apparatus 820, or the module may be provided as an apparatus including the information acquisition unit 151 and the control unit 153, and a program for causing the processor to function as the information acquisition unit 151 and the control unit 153 is provided. May be provided. In addition, a readable recording medium in which the program is recorded may be provided.

Further, in the eNB 800 illustrated in FIG. 15, the wireless communication unit 120 described with reference to FIG. 8 may be implemented in the wireless communication interface 825 (for example, the RF circuit 827). Further, the antenna unit 110 may be mounted on the antenna 810. The network communication unit 130 may be implemented in the controller 821 and / or the network interface 823.

(Second application example)
FIG. 16 is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology according to the present disclosure may be applied. The eNB 830 includes one or more antennas 840, a base station apparatus 850, and an RRH 860. Each antenna 840 and RRH 860 may be connected to each other via an RF cable. Base station apparatus 850 and RRH 860 can be connected to each other via a high-speed line such as an optical fiber cable.

Each of the antennas 840 has a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission / reception of radio signals by the RRH 860. The eNB 830 includes a plurality of antennas 840 as illustrated in FIG. 16, and the plurality of antennas 840 may respectively correspond to a plurality of frequency bands used by the eNB 830, for example. 16 shows an example in which the eNB 830 includes a plurality of antennas 840, but the eNB 830 may include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857. The controller 851, the memory 852, and the network interface 853 are the same as the controller 821, the memory 822, and the network interface 823 described with reference to FIG.

The wireless communication interface 855 supports a cellular communication method such as LTE or LTE-Advanced, and provides a wireless connection to a terminal located in a sector corresponding to the RRH 860 via the RRH 860 and the antenna 840. The wireless communication interface 855 may typically include a BB processor 856 and the like. The BB processor 856 is the same as the BB processor 826 described with reference to FIG. 15 except that the BB processor 856 is connected to the RF circuit 864 of the RRH 860 via the connection interface 857. The wireless communication interface 855 includes a plurality of BB processors 856 as illustrated in FIG. 16, and the plurality of BB processors 856 may respectively correspond to a plurality of frequency bands used by the eNB 830, for example. 16 shows an example in which the wireless communication interface 855 includes a plurality of BB processors 856, the wireless communication interface 855 may include a single BB processor 856.

The connection interface 857 is an interface for connecting the base station device 850 (wireless communication interface 855) to the RRH 860. The connection interface 857 may be a communication module for communication on the high-speed line that connects the base station apparatus 850 (wireless communication interface 855) and the RRH 860.

In addition, the RRH 860 includes a connection interface 861 and a wireless communication interface 863.

The connection interface 861 is an interface for connecting the RRH 860 (wireless communication interface 863) to the base station device 850. The connection interface 861 may be a communication module for communication on the high-speed line.

The wireless communication interface 863 transmits and receives wireless signals via the antenna 840. The wireless communication interface 863 may typically include an RF circuit 864 and the like. The RF circuit 864 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a radio signal via the antenna 840. The wireless communication interface 863 includes a plurality of RF circuits 864 as shown in FIG. 16, and the plurality of RF circuits 864 may correspond to, for example, a plurality of antenna elements, respectively. 16 illustrates an example in which the wireless communication interface 863 includes a plurality of RF circuits 864, the wireless communication interface 863 may include a single RF circuit 864.

In the eNB 830 illustrated in FIG. 16, the information acquisition unit 151 and the control unit 153 described with reference to FIG. 8 may be implemented in the wireless communication interface 855 and / or the wireless communication interface 863. Alternatively, at least some of these components may be implemented in the controller 851. As an example, the eNB 830 includes a part of the wireless communication interface 855 (for example, the BB processor 856) or / and a module including the controller 851, and the information acquisition unit 151 and the control unit 153 are mounted in the module. Also good. In this case, the module stores a program for causing the processor to function as the information acquisition unit 151 and the control unit 153 (in other words, a program for causing the processor to execute operations of the information acquisition unit 151 and the control unit 153). The program may be executed. As another example, a program for causing a processor to function as the information acquisition unit 151 and the control unit 153 is installed in the eNB 830, and the wireless communication interface 855 (for example, the BB processor 856) and / or the controller 851 execute the program. Also good. As described above, the eNB 830, the base station apparatus 850, or the module may be provided as an apparatus including the information acquisition unit 151 and the control unit 153, and a program for causing the processor to function as the information acquisition unit 151 and the control unit 153 is provided. May be provided. In addition, a readable recording medium in which the program is recorded may be provided.

In the eNB 830 illustrated in FIG. 16, for example, the wireless communication unit 120 described with reference to FIG. 8 may be implemented in the wireless communication interface 863 (for example, the RF circuit 864). The antenna unit 110 may be mounted on the antenna 840. The network communication unit 130 may be implemented in the controller 851 and / or the network interface 853.

<7.2. Application examples related to terminal devices>
(First application example)
FIG. 17 is a block diagram illustrating an example of a schematic configuration of a smartphone 900 to which the technology according to the present disclosure can be applied. The smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 912, one or more antenna switches 915. One or more antennas 916, a bus 917, a battery 918 and an auxiliary controller 919 are provided.

The processor 901 may be, for example, a CPU or a SoC (System on Chip), and controls the functions of the application layer and other layers of the smartphone 900. The memory 902 includes a RAM and a ROM, and stores programs executed by the processor 901 and data. The storage 903 can include a storage medium such as a semiconductor memory or a hard disk. The external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900.

The camera 906 includes, for example, an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and generates a captured image. The sensor 907 may include a sensor group such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor. The microphone 908 converts sound input to the smartphone 900 into an audio signal. The input device 909 includes, for example, a touch sensor that detects a touch on the screen of the display device 910, a keypad, a keyboard, a button, or a switch, and receives an operation or information input from a user. The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays an output image of the smartphone 900. The speaker 911 converts an audio signal output from the smartphone 900 into audio.

The wireless communication interface 912 supports any cellular communication method such as LTE or LTE-Advanced, and performs wireless communication. The wireless communication interface 912 may typically include a BB processor 913, an RF circuit 914, and the like. The BB processor 913 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and performs various signal processing for wireless communication. On the other hand, the RF circuit 914 may include a mixer, a filter, an amplifier, and the like, and transmits and receives radio signals via the antenna 916. The wireless communication interface 912 may be a one-chip module in which the BB processor 913 and the RF circuit 914 are integrated. The wireless communication interface 912 may include a plurality of BB processors 913 and a plurality of RF circuits 914 as illustrated in FIG. FIG. 17 shows an example in which the wireless communication interface 912 includes a plurality of BB processors 913 and a plurality of RF circuits 914. However, the wireless communication interface 912 includes a single BB processor 913 or a single RF circuit 914. But you can.

Furthermore, the wireless communication interface 912 may support other types of wireless communication methods such as a short-range wireless communication method, a proximity wireless communication method, or a wireless LAN (Local Area Network) method in addition to the cellular communication method. In that case, a BB processor 913 and an RF circuit 914 for each wireless communication method may be included.

Each of the antenna switches 915 switches the connection destination of the antenna 916 among a plurality of circuits (for example, circuits for different wireless communication systems) included in the wireless communication interface 912.

Each of the antennas 916 includes a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission / reception of a radio signal by the radio communication interface 912. The smartphone 900 may include a plurality of antennas 916 as illustrated in FIG. Note that although FIG. 17 illustrates an example in which the smartphone 900 includes a plurality of antennas 916, the smartphone 900 may include a single antenna 916.

Furthermore, the smartphone 900 may include an antenna 916 for each wireless communication method. In that case, the antenna switch 915 may be omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 912, and auxiliary controller 919 to each other. . The battery 918 supplies electric power to each block of the smartphone 900 shown in FIG. 17 through a power supply line partially shown by a broken line in the drawing. For example, the auxiliary controller 919 operates the minimum necessary functions of the smartphone 900 in the sleep mode.

17, the information acquisition unit 241 and the control unit 243 described with reference to FIG. 9 may be implemented in the wireless communication interface 912. Alternatively, at least some of these components may be implemented in the processor 901 or the auxiliary controller 919. As an example, the smartphone 900 includes a module including a part (for example, the BB processor 913) or all of the wireless communication interface 912, the processor 901, and / or the auxiliary controller 919, and the information acquisition unit 241 and the control unit in the module. 243 may be implemented. In this case, the module stores a program for causing the processor to function as the information acquisition unit 241 and the control unit 243 (in other words, a program for causing the processor to execute operations of the information acquisition unit 241 and the control unit 243). The program may be executed. As another example, a program for causing a processor to function as the information acquisition unit 241 and the control unit 243 is installed in the smartphone 900, and the wireless communication interface 912 (for example, the BB processor 913), the processor 901, and / or the auxiliary controller 919 is installed. The program may be executed. As described above, the smartphone 900 or the module may be provided as an apparatus including the information acquisition unit 241 and the control unit 243, or a program for causing the processor to function as the information acquisition unit 241 and the control unit 243 may be provided. Good. In addition, a readable recording medium in which the program is recorded may be provided.

Further, in the smartphone 900 shown in FIG. 17, for example, the wireless communication unit 220 described with reference to FIG. 9 may be implemented in the wireless communication interface 912 (for example, the RF circuit 914). The antenna unit 210 may be mounted on the antenna 916.

(Second application example)
FIG. 18 is a block diagram illustrating an example of a schematic configuration of a car navigation device 920 to which the technology according to the present disclosure can be applied. The car navigation device 920 includes a processor 921, a memory 922, a GPS (Global Positioning System) module 924, a sensor 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, a speaker 931, and wireless communication. The interface 933 includes one or more antenna switches 936, one or more antennas 937, and a battery 938.

The processor 921 may be a CPU or SoC, for example, and controls the navigation function and other functions of the car navigation device 920. The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921.

The GPS module 924 measures the position (for example, latitude, longitude, and altitude) of the car navigation device 920 using GPS signals received from GPS satellites. The sensor 925 may include a sensor group such as a gyro sensor, a geomagnetic sensor, and an atmospheric pressure sensor. The data interface 926 is connected to the in-vehicle network 941 through a terminal (not shown), for example, and acquires data generated on the vehicle side such as vehicle speed data.

The content player 927 reproduces content stored in a storage medium (for example, CD or DVD) inserted into the storage medium interface 928. The input device 929 includes, for example, a touch sensor, a button, or a switch that detects a touch on the screen of the display device 930, and receives an operation or information input from the user. The display device 930 has a screen such as an LCD or an OLED display, and displays a navigation function or an image of content to be reproduced. The speaker 931 outputs the navigation function or the audio of the content to be played back.

The wireless communication interface 933 supports any cellular communication method such as LTE or LTE-Advanced, and performs wireless communication. The wireless communication interface 933 may typically include a BB processor 934, an RF circuit 935, and the like. The BB processor 934 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and performs various signal processing for wireless communication. On the other hand, the RF circuit 935 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a radio signal via the antenna 937. The wireless communication interface 933 may be a one-chip module in which the BB processor 934 and the RF circuit 935 are integrated. The wireless communication interface 933 may include a plurality of BB processors 934 and a plurality of RF circuits 935 as shown in FIG. 18 shows an example in which the wireless communication interface 933 includes a plurality of BB processors 934 and a plurality of RF circuits 935, the wireless communication interface 933 includes a single BB processor 934 or a single RF circuit 935. But you can.

Further, the wireless communication interface 933 may support other types of wireless communication methods such as a short-range wireless communication method, a proximity wireless communication method, or a wireless LAN method in addition to the cellular communication method. A BB processor 934 and an RF circuit 935 may be included for each communication method.

Each of the antenna switches 936 switches the connection destination of the antenna 937 among a plurality of circuits included in the wireless communication interface 933 (for example, circuits for different wireless communication systems).

Each of the antennas 937 has a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission / reception of a radio signal by the radio communication interface 933. The car navigation device 920 may include a plurality of antennas 937 as shown in FIG. 18 illustrates an example in which the car navigation apparatus 920 includes a plurality of antennas 937, the car navigation apparatus 920 may include a single antenna 937.

Furthermore, the car navigation device 920 may include an antenna 937 for each wireless communication method. In that case, the antenna switch 936 may be omitted from the configuration of the car navigation device 920.

The battery 938 supplies power to each block of the car navigation apparatus 920 shown in FIG. 18 through a power supply line partially shown by a broken line in the figure. Further, the battery 938 stores electric power supplied from the vehicle side.

In the car navigation device 920 shown in FIG. 18, the information acquisition unit 241 and the control unit 243 described with reference to FIG. 9 may be implemented in the wireless communication interface 933. Alternatively, at least some of these components may be implemented in the processor 921. As an example, the car navigation device 920 includes a module including a part (for example, the BB processor 934) or all of the wireless communication interface 933 and / or the processor 921, and the information acquisition unit 241 and the control unit 243 are mounted in the module. May be. In this case, the module stores a program for causing the processor to function as the information acquisition unit 241 and the control unit 243 (in other words, a program for causing the processor to execute operations of the information acquisition unit 241 and the control unit 243). The program may be executed. As another example, a program for causing a processor to function as the information acquisition unit 241 and the control unit 243 is installed in the car navigation device 920, and the wireless communication interface 933 (for example, the BB processor 934) and / or the processor 921 executes the program. May be executed. As described above, the car navigation device 920 or the module may be provided as a device including the information acquisition unit 241 and the control unit 243, and a program for causing the processor to function as the information acquisition unit 241 and the control unit 243 is provided. May be. In addition, a readable recording medium in which the program is recorded may be provided.

Further, in the car navigation apparatus 920 shown in FIG. 18, for example, the wireless communication unit 220 described with reference to FIG. 9 may be implemented in the wireless communication interface 933 (for example, the RF circuit 935). The antenna unit 210 may be mounted on the antenna 937.

Also, the technology according to the present disclosure may be realized as an in-vehicle system (or vehicle) 940 including one or more blocks of the car navigation device 920 described above, an in-vehicle network 941, and a vehicle side module 942. That is, an in-vehicle system (or vehicle) 940 may be provided as a device including the information acquisition unit 241 and the control unit 243. The vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine speed, or failure information, and outputs the generated data to the in-vehicle network 941.

<< 8. Summary >>
So far, each device and each process according to the embodiment of the present disclosure has been described with reference to FIGS.

(1) First Embodiment According to the first embodiment, the terminal device 200 includes a plurality of precoding matrices respectively corresponding to a channel estimated from a channel quality measurement reference signal and a plurality of directional beams. And an information acquisition unit 241 that acquires the interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices.

(2) Second Embodiment According to the second embodiment, the base station 100 includes a plurality of precoding matrices each corresponding to a channel estimated from a channel quality measurement reference signal and a plurality of directional beams. And a control unit 153 that calculates the amount of interference of each of the plurality of directional beams based on the channel and the plurality of precoding matrices.

(3) Third Embodiment According to the third embodiment, the base station 100 obtains power increase information related to an increase in transmission power of a channel quality measurement reference signal transmitted by the neighboring base station 300. An acquisition unit 151 and a control unit 153 that performs control for correcting an interference amount calculated from the reference signal using the power increase information.

According to the first to third embodiments, for example, it becomes possible to know the state of directional beam interference more appropriately.

As mentioned above, although preferred embodiment of this indication was described referring an accompanying drawing, it cannot be overemphasized that this indication is not limited to the example concerned. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present disclosure. Understood.

For example, although the example in which the system is a system compliant with LTE, LTE-Advanced, or a communication standard based on these has been described, the present disclosure is not limited to such an example. For example, the communication system may be a system that complies with other communication standards.

In addition, the processing steps in the processing of the present specification do not necessarily have to be executed in time series according to the order described in the flowchart or the sequence diagram. For example, the processing steps in the processing may be executed in an order different from the order described as a flowchart or a sequence diagram, or may be executed in parallel.

In addition, a processor (for example, a CPU, a DSP, or the like) included in a device of the present specification (for example, a base station, a base station device, a module for a base station device, or a terminal device or a module for a terminal device) is provided. It is also possible to create a computer program (in other words, a computer program for causing the processor to execute the operation of the component of the device) to function as a component of the device (for example, an information acquisition unit and a control unit). . Moreover, a recording medium on which the computer program is recorded may be provided. An apparatus (for example, a base station, a base station apparatus, a module for a base station apparatus, a terminal apparatus, or a device including a memory for storing the computer program and one or more processors capable of executing the computer program) A module for a terminal device may also be provided. In addition, a method including the operation of the components of the device (for example, an information acquisition unit and a communication control unit) is also included in the technology according to the present disclosure.

In addition, the effects described in the present specification are merely illustrative or illustrative, and are not limited. That is, the technology according to the present disclosure can exhibit other effects that are apparent to those skilled in the art from the description of the present specification in addition to or instead of the above effects.

The following configurations also belong to the technical scope of the present disclosure.
(1)
An acquisition unit that acquires a channel estimated from a reference signal for channel quality measurement and a plurality of precoding matrices respectively corresponding to a plurality of directional beams;
A control unit that calculates an interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices;
A device comprising:
(2)
The channel is a channel estimated by a terminal device,
The reference signal is a signal transmitted by a peripheral base station of a serving base station of the terminal device,
The apparatus according to (1) above.
(3)
The device according to (2), wherein the device is the terminal device or a module for the terminal device.
(4)
The apparatus according to (2), wherein the apparatus is the serving base station, a base station apparatus for the serving base station, or a module for the base station apparatus.
(5)
The apparatus according to any one of (2) to (4), wherein the plurality of precoding matrices are a part of all defined precoding matrices.
(6)
The apparatus according to (5), wherein the plurality of precoding matrices are precoding matrices that the neighboring base station notifies to the serving base station.
(7)
The apparatus according to (5) or (6), wherein the plurality of directional beams are directional beams in which directivity in one of a horizontal direction and a vertical direction is limited.
(8)
The apparatus according to any one of (1) to (7), wherein the reference signal is a channel state information reference signal (CSI-RS).
(9)
An acquisition unit for acquiring information indicating a configuration of a reference signal for channel quality measurement;
A control unit for notifying the terminal device of the configuration;
With
The acquisition unit acquires a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the information indicating the plurality of precoding matrices being a part of all defined precoding matrices. And
The control unit notifies the terminal device of the plurality of precoding matrices in association with the configuration.
apparatus.
(10)
The apparatus according to (9), wherein the configuration includes at least one of a radio resource used for transmission of the reference signal and a sequence of the reference signal.
(11)
The device according to (9) or (10), wherein the control unit notifies the terminal device of a neighboring base station that transmits the reference signal in association with the configuration.
(12)
The terminal device is a terminal device that calculates the amount of interference of each of the plurality of directional beams based on a channel estimated from the reference signal and the plurality of precoding matrices, (9) to (11) The apparatus of any one of these.
(13)
An acquisition unit for acquiring power increase information related to an increase in transmission power of a reference signal for channel quality measurement transmitted by a neighboring base station;
A control unit that performs control for correcting an interference amount calculated from the reference signal using the power increase information;
A device comprising:
(14)
The device according to (13), wherein the control is notification of the power increase information to a terminal device that calculates an interference amount from the reference signal.
(15)
The apparatus according to (13), wherein the control is to correct an interference amount calculated from the reference signal based on the power increase information.
(16)
The apparatus according to (15), wherein the apparatus is a base station, a base station apparatus for the base station, or a module for the base station apparatus.
(17)
The device is a terminal device or a module for the terminal device,
The power increase information is information notified to the terminal device by the serving base station of the terminal device.
The device according to (15) above.
(18)
The apparatus according to any one of (13) to (17), wherein the power increase information is information provided by the neighboring base station.
(19)
The apparatus according to any one of (13) to (18), wherein the power increase information indicates an increase amount of transmission power of the reference signal.
(20)
The control unit includes a first radio resource in which a reference signal for channel quality measurement is transmitted by two or more neighboring base stations, and a reference signal for channel quality measurement by two or more other neighboring base stations. Notifying the terminal device of the second radio resource to be transmitted,
The received power of the reference signal transmitted in the first radio resource in the terminal device is larger than the received power of the reference signal transmitted in the second radio resource in the terminal device.
The apparatus according to any one of (13) to (19).
(21)
Depending on the processor
Obtaining a channel estimated from a reference signal for channel quality measurement and a plurality of precoding matrices respectively corresponding to a plurality of directional beams;
Calculating an interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices;
Including methods.
(22)
Obtaining a channel estimated from a reference signal for channel quality measurement and a plurality of precoding matrices respectively corresponding to a plurality of directional beams;
Calculating an interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices;
A program that causes a processor to execute.
(23)
Obtaining a channel estimated from a reference signal for channel quality measurement and a plurality of precoding matrices respectively corresponding to a plurality of directional beams;
Calculating an interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices;
A readable recording medium on which a program for causing a processor to execute is recorded.
(24)
Depending on the processor
Obtaining information indicating the configuration of a reference signal for channel quality measurement;
Notifying the terminal device of the configuration;
Obtaining a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the information indicating the plurality of precoding matrices being a part of all defined precoding matrices;
In association with the configuration, notifying the terminal device of the plurality of precoding matrices;
Including methods.
(25)
Obtaining information indicating the configuration of a reference signal for channel quality measurement;
Notifying the terminal device of the configuration;
Obtaining a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the information indicating the plurality of precoding matrices being a part of all defined precoding matrices;
In association with the configuration, notifying the terminal device of the plurality of precoding matrices;
A program that causes a processor to execute.
(26)
Obtaining information indicating the configuration of a reference signal for channel quality measurement;
Notifying the terminal device of the configuration;
Obtaining a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the information indicating the plurality of precoding matrices being a part of all defined precoding matrices;
In association with the configuration, notifying the terminal device of the plurality of precoding matrices;
A readable recording medium on which a program for causing a processor to execute is recorded.
(27)
Depending on the processor
Obtaining power increase information regarding an increase in transmission power of a reference signal for channel quality measurement transmitted by a neighboring base station;
Performing control for correcting the amount of interference calculated from the reference signal using the power increase information;
Including methods.
(28)
Obtaining power increase information regarding an increase in transmission power of a reference signal for channel quality measurement transmitted by a neighboring base station;
Performing control for correcting the amount of interference calculated from the reference signal using the power increase information;
A program that causes a processor to execute.
(29)
Obtaining power increase information regarding an increase in transmission power of a reference signal for channel quality measurement transmitted by a neighboring base station;
Performing control for correcting the amount of interference calculated from the reference signal using the power increase information;
A readable recording medium on which a program for causing a processor to execute is recorded.

DESCRIPTION OF SYMBOLS 1 System 100 Base station 101 Cell 151 Information acquisition part 153 Control part 200 Terminal device 241 Information acquisition part 243 Control part

Claims

An acquisition unit that acquires a channel estimated from a reference signal for channel quality measurement and a plurality of precoding matrices respectively corresponding to a plurality of directional beams;
A control unit that calculates an interference amount of each of the plurality of directional beams based on the channel and the plurality of precoding matrices;
A device comprising:
The channel is a channel estimated by a terminal device,
The reference signal is a signal transmitted by a peripheral base station of a serving base station of the terminal device,
The apparatus of claim 1.
The apparatus according to claim 2, wherein the apparatus is the terminal apparatus or a module for the terminal apparatus.
The apparatus according to claim 2, wherein the apparatus is the serving base station, a base station apparatus for the serving base station, or a module for the base station apparatus.
The apparatus according to claim 2, wherein the plurality of precoding matrices are a part of all defined precoding matrices.
The apparatus according to claim 5, wherein the plurality of precoding matrices are precoding matrices that the neighboring base station notifies to the serving base station.
The apparatus according to claim 5, wherein the plurality of directional beams are directional beams having limited directivity in one of a horizontal direction and a vertical direction.
The apparatus according to claim 1, wherein the reference signal is a channel state information reference signal (CSI-RS).
An acquisition unit for acquiring information indicating a configuration of a reference signal for channel quality measurement;
A control unit for notifying the terminal device of the configuration;
With
The acquisition unit acquires a plurality of precoding matrices respectively corresponding to a plurality of directional beams, the information indicating the plurality of precoding matrices being a part of all defined precoding matrices. And
The control unit notifies the terminal device of the plurality of precoding matrices in association with the configuration.
apparatus.
The apparatus according to claim 9, wherein the configuration includes at least one of a radio resource used for transmission of the reference signal and a sequence of the reference signal.
The device according to claim 9, wherein the control unit notifies the terminal device of a neighboring base station that transmits the reference signal in association with the configuration.
The apparatus according to claim 9, wherein the terminal apparatus is a terminal apparatus that calculates an interference amount of each of the plurality of directional beams based on a channel estimated from the reference signal and the plurality of precoding matrices.
An acquisition unit for acquiring power increase information related to an increase in transmission power of a reference signal for channel quality measurement transmitted by a neighboring base station;
A control unit that performs control for correcting an interference amount calculated from the reference signal using the power increase information;
A device comprising:
The apparatus according to claim 13, wherein the control is to notify the terminal apparatus that calculates an interference amount from the reference signal of the power increase information.
The apparatus according to claim 13, wherein the control is to correct an interference amount calculated from the reference signal based on the power increase information.
The apparatus according to claim 15, wherein the apparatus is a base station, a base station apparatus for the base station, or a module for the base station apparatus.
The device is a terminal device or a module for the terminal device,
The power increase information is information notified to the terminal device by the serving base station of the terminal device.
The apparatus according to claim 15.
The apparatus according to claim 13, wherein the power increase information is information provided by the neighboring base station.
The apparatus according to claim 13, wherein the power increase information indicates an increase amount of transmission power of the reference signal.
The control unit includes a first radio resource in which a reference signal for channel quality measurement is transmitted by two or more neighboring base stations, and a reference signal for channel quality measurement by two or more other neighboring base stations. Notifying the terminal device of the second radio resource to be transmitted,
The received power of the reference signal transmitted in the first radio resource in the terminal device is larger than the received power of the reference signal transmitted in the second radio resource in the terminal device.
The apparatus of claim 13.