JP6888663B2 - Terminal equipment, base stations, methods and recording media - Google Patents

Description

The present disclosure relates to terminal equipment, base stations, methods and recording media.

In recent years, 3GPP (Third Generation Partnership Project) has been discussing 5G, which is the next-generation communication standard. The communication technology that constitutes 5G is also called NR (New Radio Access Technology).

One of the study items of 3GPP Release 14 is MIMO (multiple-input and multiple-output) for NR. MIMO is a technique for performing beamforming using a plurality of antennas, and includes 3D (or Full Dimension) -MIMO capable of beamforming in a three-dimensional direction, Massive-MIMO using a large number of antennas, and the like. MIMO is required to improve the accuracy of beam tracking technology that continuously provides an appropriate beam to a user terminal.

For example, Patent Document 1 below discloses a technique for determining a beam for a user device based on feedback information from the user device regarding beamforming.

Japanese Unexamined Patent Publication No. 2015-164281

However, the technology related to beam tracking proposed in the above patent documents and the like is still under discussion, and it cannot be said that a sufficient proposal has been made. For example, a technique for improving the continuity of beam tracking is one of the poorly proposed techniques.

According to the present disclosure, a group of terminal devices including a communication unit that communicates with a base station that forms and communicates with a plurality of beams, and a plurality of downlink reference signals transmitted from the base station using the beams. Report the first report information for downlink user data and the second report information for beam tracking for the terminal device by the base station to the base station regarding the reception result of the downlink reference signal. A terminal device including a control unit is provided.

Further, according to the present disclosure, a communication unit that forms a plurality of beams and communicates with the terminal device, and a group of downlink reference signals including a plurality of downlink reference signals transmitted using the beams are transmitted to the terminal device. The reception of the first report information for downlink user data regarding the reception result of the group of downlink reference signals and the second report information for beam tracking for the terminal device from the terminal device, Further, a base station including a control unit for performing a first transmission setting based on the first report information and a second transmission setting based on the second report information is provided.

Further, according to the present disclosure, a communication unit that forms a plurality of beams and communicates with the base station, and a control unit that transmits each of the plurality of uplink reference signals using beams directed in different directions are provided. A terminal device is provided.

Further, according to the present disclosure, a communication unit that forms a plurality of beams and communicates with the terminal device, and a plurality of routes in which each of the plurality of groups of downlink reference signals arrives from different directions for the terminal device, respectively. A base station is provided that comprises a control unit that transmits using a group of beams via.

Further, according to the present disclosure, a group of downlink reference signals including a plurality of downlink reference signals transmitted from the base station by using the beams and communicating with a base station that forms and communicates with a plurality of beams. The processor reports to the base station the first report information for downlink user data and the second report information for beam tracking for the terminal device by the base station regarding the reception result. Methods are provided that include.

Further, according to the present disclosure, a group of downs including a communication unit that communicates a computer with a base station that forms and communicates with a plurality of beams, and a plurality of downlink reference signals transmitted from the base station using the beams. Control to report the first report information for downlink user data and the second report information for beam tracking for the terminal device by the base station to the base station regarding the reception result of the link reference signal. A recording medium on which a program for functioning as a unit is recorded is provided.

Further, according to the present disclosure, a plurality of beams are formed to communicate with a terminal device, and a group of downlink reference signals including a plurality of downlink reference signals to be transmitted using the beams are transmitted to the terminal device. The reception of the first report information for downlink user data regarding the reception result of the group of downlink reference signals and the second report information for beam tracking for the terminal device from the terminal device, and the reception of the second report information for beam tracking for the terminal device. A method is provided including, in which a processor performs a first transmission setting based on the first report information and a second transmission setting based on the second report information.

Further, according to the present disclosure, the terminal device of a group of downlink reference signals including a communication unit that forms a plurality of beams and communicates with the terminal device and a plurality of downlink reference signals transmitted by using the beams. From the terminal device, the first report information for downlink user data regarding the reception result of the group of downlink reference signals and the second report information for beam tracking for the terminal device. Provided is a recording medium recording a program for functioning as a control unit that performs reception of the above, a first transmission setting based on the first report information, and a second transmission setting based on the second report information. Will be done.

Further, the present disclosure includes forming a plurality of beams to communicate with a base station, and transmitting each of the plurality of uplink reference signals by a processor using beams directed in different directions. A method is provided.

Further, according to the present disclosure, a communication unit that forms a plurality of beams and communicates with a base station, and a control unit that transmits each of the plurality of uplink reference signals using beams directed in different directions. A recording medium on which a program for functioning as, is recorded is provided.

Further, according to the present disclosure, a plurality of beams are formed to communicate with the terminal device, and each of the plurality of groups of downlink reference signals is used for each of the plurality of paths arriving from different directions for the terminal device. Methods are provided that include, and include transmission by a processor with a set of beams passing through.

Further, according to the present disclosure, a communication unit that forms a plurality of beams of a computer to communicate with a terminal device, and a plurality of groups of downlink reference signals that come from different directions for the terminal device. A control unit that transmits using a group of beams passing through each of the routes and a recording medium on which a program for functioning as a function are recorded are provided.

As described above, according to the present disclosure, it is possible to improve the continuity of beam tracking. It should be noted that the above effects are not necessarily limited, and either in combination with or in place of the above effects, any of the effects shown herein, or any other effect that can be grasped from this specification. May be played.

It is a figure for demonstrating an example of the structure of the system which concerns on one Embodiment of this disclosure. It is a figure for demonstrating consideration about beam tracking. It is a sequence diagram which shows an example of the flow of the beam tracking procedure based on a beam foamed CSI-RS. It is a sequence diagram which shows an example of the flow of the beam tracking procedure based on SRS. It is a figure for demonstrating an example of the format of SRS in LTE. It is a figure for demonstrating the narrow band SRS in LTE. It is a block diagram which shows an example of the structure of the base station which concerns on this embodiment. It is a block diagram which shows an example of the structure of the terminal apparatus which concerns on this embodiment. It is a figure for demonstrating the technical problem about a beam-formed downlink reference signal. It is a figure for demonstrating the technical problem about a beam-formed downlink reference signal. It is a figure for demonstrating the technical problem about a beam-formed downlink reference signal. It is a figure for demonstrating the technical problem about a beam-formed downlink reference signal. It is a figure for demonstrating the 1st report information and 2nd report information which concerns on 1st Embodiment. It is a figure for demonstrating the report timing of the 1st report information and 2nd report information which concerns on this Embodiment. It is a figure for demonstrating the report timing of the 1st report information and 2nd report information which concerns on this Embodiment. It is a figure for demonstrating the report timing of the 1st report information and 2nd report information which concerns on this Embodiment. It is a sequence diagram which shows an example of the flow of the beam tracking processing executed in the system which concerns on this embodiment. It is a figure for demonstrating the uplink reference signal which concerns on 2nd Embodiment. It is a figure for demonstrating the uplink reference signal which concerns on this Embodiment. It is a figure for demonstrating the uplink reference signal which concerns on this Embodiment. It is a figure for demonstrating the downlink reference signal which concerns on this Embodiment. It is a figure for demonstrating the downlink reference signal which concerns on this Embodiment. It is a figure for demonstrating the downlink reference signal which concerns on this Embodiment. It is a figure for demonstrating the report of the report information which concerns on this embodiment. It is a sequence diagram which shows an example of the flow of communication processing executed in the system which concerns on this embodiment. It is a sequence diagram which shows an example of the flow of communication processing executed in the system which concerns on the modification of this Embodiment. It is a block diagram which shows 1st example of the schematic structure of eNB. It is a block diagram which shows the 2nd example of the schematic structure of eNB. It is a block diagram which shows an example of the schematic structure of a smartphone. It is a block diagram which shows an example of the schematic structure of a car navigation device.

Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

Further, in the present specification and the drawings, elements having substantially the same functional configuration may be distinguished by adding different alphabets after the same reference numerals. For example, a plurality of elements having substantially the same functional configuration are distinguished as needed, such as base stations 100A, 100B and 100C. However, if it is not necessary to distinguish each of a plurality of elements having substantially the same functional configuration, only the same reference numerals are given. For example, when it is not necessary to distinguish between base stations 100A, 100B and 100C, it is simply referred to as base station 100.

The explanations will be given in the following order.
1. 1. System configuration example 2. Consideration on beam tracking 2.1. Outline of beam tracking 2.2. SRS
2.3. Others 3. Configuration example of each device 3.1. Base station configuration example 3.2. Configuration of terminal device 4. First Embodiment 4.1. Technical issues 4.2. Technical features 5. Second Embodiment 5.1. Technical issues 5.2. Technical features 5.3. Modification example 6. Application example 7. Summary

<< 1. System configuration example >>
First, an example of the configuration of the system according to the embodiment of the present disclosure will be described with reference to FIG. FIG. 1 is a diagram for explaining an example of the configuration of the system according to the present embodiment. As shown in FIG. 1, the system 1 according to the present embodiment includes a base station 100 and a terminal device 200.

The base station 100 is a device that operates the cell 11 and provides a wireless communication service to the terminal device 200 in the cell 11. As shown in FIG. 1, a plurality of base stations 100 may exist, and the base stations 100A to 100C operate cells 11A to 11C, respectively, and provide wireless communication services to the terminal devices 200A to 200C, respectively. In the example shown in FIG. 1, base stations 100A and 100B are small cell base stations, and cells 11A and 11B are small cells. Further, the base station 100C is a macro cell base station, and the cell 11C is a macro cell. The macrocell base station 100C has a function of cooperatively controlling wireless communication by the small cell base stations 100A and 100B under control. The base stations 100 are connected so as to be able to communicate with each other, and are connected by, for example, an X2 interface. Further, the base station 100 and the core network 12 are communicably connected, and are connected by, for example, the S1 interface.

The terminal device 200 is a device that communicates with the base station 100. The terminal device 200 typically has high mobility, and cell selection is performed according to the movement. In addition, when a beam is formed by the base station 100 or the terminal device 200, beam tracking for forming and communicating an appropriate beam according to the movement of the terminal device 200 is performed.

The base station may also be referred to as an eNB (evolved Node B) below. This is not limited to the fact that the base station 100 is operated by the wireless access technology in LTE, but can be operated by the wireless access technology of 5G. That is, the base station may be called other than eNB. Similarly, the terminal device may also be referred to below as a UE (User Equipment) or a user, but this is not limited to the terminal device 200 being operated by the wireless access technology in LTE, and the 5G wireless system is used. Can be operated by access technology.

The core network 12 includes a control node that controls the base station 100. The core network 12 may include, for example, an EPC (Evolved Packet Core) or a 5G architecture. The core network 12 is connected to the packet data network via the gateway device.

<< 2. Consideration on beam tracking >>
Hereinafter, consideration regarding beam tracking will be made from each viewpoint.

<2.1. Overview of beam tracking>
(Necessity of beam tracking)
It is assumed that the eNB is equipped with a very large number of antennas (more specifically, antenna elements), for example, 256 antennas in the 30 GHz band and 1000 antennas in the 70 GHz band. As the number of antenna elements increases, it becomes possible to form a sharper beam. For example, it is possible to provide a very sharp beam from the eNB to the UE, such that the full width at half maximum (indicating how many times the level of 3 dB drop occurs) is 1 degree or less.

When the UE moves at high speed (for example, when moving at 500 km / h) in an environment where a very sharp beam is formed, it is assumed that the UE easily goes out of the beam. If the UE goes out of the beam, it becomes difficult to transmit data from the eNB to the UE. Therefore, as shown in FIG. 2, it is desirable that the beam can be tracked to the UE moving at high speed.

FIG. 2 is a diagram for explaining consideration regarding beam tracking. As shown in FIG. 2, it is desirable to follow the beam formed by the eNB according to the movement of the UE.

(Codebook base beamforming)
In LTE, it is unlikely that a mechanism will be adopted in which the beam is changed steplessly to recreate the beam that follows the UE. This is because there is a computational cost to recreate a new beam. Therefore, 3GPP Release 13 provides a mechanism in which beams directed from the eNB in all directions are formed in advance, and a beam used for communication with the UE is selected and provided from the preformed beams. It is used in FD-MIMO (full dimension multi input multi output). Such a mechanism is also called codebook based beam forming.

For example, when beams are prepared in 1 degree increments with respect to 360 degrees in the horizontal direction, 360 beams are prepared. If the beams overlap in half, 720 beams will be prepared. If beams are similarly prepared for −90 degrees to +90 degrees in the vertical direction, 360 beams for 180 degrees will be prepared.

In codebook-based beamforming, beamtracking means continuously selecting a beam suitable for communication with a UE from beams prepared in advance as a codebook.

(Beam tracking based on downlink reference signal)
In 3GPP RAN1 Release 13 FD-MIMO, a study on beam selection was conducted. In this study, it was considered that the eNB selects a beam suitable for communication with the UE based on a downlink beam-formed reference signal (RS). Such a downlink reference signal is also referred to as a beam-formed CSI-RS (channel state information-reference signal). The eNB provides a plurality of beamformed CSI-RS (multiple beamformed CSI-RS), and communicates with the UE by using a beam according to a reception result in the UE. Hereinafter, the beam tracking procedure based on the beam-formed CSI-RS will be described with reference to FIG.

FIG. 3 is a sequence diagram showing an example of the flow of the beam tracking procedure based on the beam-formed CSI-RS. As shown in FIG. 3, first, the eNB transmits a plurality of beam-formed CSI-RSs using a plurality of beams (step S11). The UE then selects the desired beam from the plurality of beams used for transmitting the beam-formed CSI-RS based on the reception results of the plurality of beam-formed CSI-RS provided, and selects the selection result. The indicated information is transmitted to the eNB (step S12). The information indicating the selection result includes the desired beam identification information (typically the beam number). For example, the UE selects one or more desired beams based on the received power of each beam. Then, the eNB provides the UE with user data beam-formed by the selected beam (step S13).

According to such a procedure, the tracking ability varies depending on how often a set of a plurality of beam-formed CSI-RSs is provided to the UE. For example, if provided every 100 ms, the tracking will be done with a particle size of 100 ms. If the UE is moving at a speed that stays in the beam for 100 ms, tracking at this particle size is fine, but if the UE speed is increased, for example, if tracking at a particle size of 5 ms or less is required. Will also come out. In such a case, the overhead of downlink resources for providing a plurality of beam-formed CSI-RS sets becomes large, which makes efficient communication difficult.

(Beam tracking based on uplink reference signal)
The eNB determines which plurality of beams to transmit the plurality of beam-formed CSI-RSs described above, typically based on the uplink reference signal. The eNB grasps the rough position of the UE based on the uplink reference signal, selects a plurality of beam candidates suitable for the UE, and uses the selected beam candidates to form a plurality of beams. Send CSI-RS. This uplink reference signal is also referred to as an SRS (Sounding Reference Signal). Hereinafter, the beam tracking procedure based on SRS will be described with reference to FIG.

FIG. 4 is a sequence diagram showing an example of the flow of the beam tracking procedure based on SRS. As shown in FIG. 4, the UE first transmits the SRS to the eNB (step S21). The eNB then acquires channel information between the UE and the eNB based on the reception result of the SRS, and selects a plurality of beams to be used for transmitting the plurality of beam-formed CSI-RSs based on the channel information ( Step S22). After that, in steps S23 to 25, the same processing as that according to steps S11 to S13 described above with reference to FIG. 3 is performed.

Here, in the case of TDD (Time Division duplex), since the radio resource is used by alternately switching between the uplink and the downlink in time, the channel information is the same for the uplink and the downlink. On the other hand, in the case of FDD (Frequency Division duplex), since the frequencies used by the uplink and the downlink are different, the channel information is different between the uplink and the downlink. Therefore, in step S21, it can be said that the eNB can acquire (accurately estimate) the downlink channel information based on the SRS only in the case of TDD.

<2.2. SRS>
The main purpose of the SRS is to acquire uplink channel information in the frequency bandwidth (that is, bandwidth) operated by the eNB and use it for downlink scheduling, rather than the beam selection described above.

Scheduling means that the eNB determines which part of the downlink or uplink resource (unit resource separated by frequency and time) to be used by the UE, and notifies the UE of the determined content. For example, when the bandwidth operated by the eNB is 20 MHz, the resource block includes 12 subcarriers arranged at 15 kHz intervals, and 100 resource blocks are spread in 20 MHz. The resources of the 100 resource blocks are shared and used by a plurality of UEs. That is, FDM (Frequency Division Multiplexing) is performed. Therefore, it can be said that eNB scheduling is to determine which part of 20 MHz is used by the UE.

The eNB achieves the above-mentioned main objectives based on the SRS. Specifically, the eNB acquires uplink channel information based on the SRS reception result, estimates downlink channel information based on the acquired channel information, and schedules based on the estimated downlink channel information. Do.

Such an existing SRS designed for the main purpose of scheduling is considered unsuitable as a reference signal for beam selection. For example, beam tracking does not necessarily require channel information across channels.

(SRS format)
FIG. 5 is a diagram for explaining an example of the SRS format in LTE. The LTE uplink is operated by SC-FDMA (Single Carrier Frequency Division Multiple Access) and contains 14 symbols per subframe. Symbols in the time direction in the uplink are also referred to as SC-FDMA symbols or OFDM symbols. As shown in FIG. 5, the SRS is transmitted using the last OFDM symbol. However, SRS is not always transmitted using the last OFDM symbol in all subframes. For example, normally, PUSCH (Physical Uplink Shared Channel), which is user data, and PUCCH (Physical Uplink Control Channel), which is a control signal, are transmitted using all 14 OFDM symbols. Then, only when necessary, the SRS is transmitted using the last OFDM symbol.

(Narrowband SRS and wideband SRS)
As shown in FIG. 5, the SRS may occupy the entire operating bandwidth and be transmitted at one time. On the other hand, a part of the bandwidth to be operated may be used in one transmission of SRS. The former is also referred to as a wideband SRS, and the latter is also referred to as a narrowband SRS.

FIG. 6 is a diagram for explaining a narrow band SRS in LTE. As shown in FIG. 6, the narrow band SRS uses a part of the bandwidth in one transmission. However, in order to achieve the above-mentioned main purpose of knowing the channel state of the entire operating bandwidth, even in the narrow band SRS, by shifting the bandwidth used for transmission as shown in FIG. Eventually, the SRS will be transmitted over the entire bandwidth in operation. The advantage of narrowband SRS is that the UE can use more power to transmit the SRS at one time, which can increase the uplink coverage of the SRS. In other words, the merit of the narrow band SRS is that the quality of the SRS received by the eNB can be improved.

It should be noted here that both wideband and narrowband SRS are designed mainly for the purpose of acquiring channel information of the entire bandwidth to be operated. That is, the target bandwidth for both wideband and narrowband SRS is the entire bandwidth operated by the eNB.

(Periodic SRS and aperiodic SRS)
The eNB can be configured in the UE to transmit the SRS periodically or aperiodically.

When setting periodic SRS, eNB is set to quasi-static (semi-static) using RRC (Radio Resource Control) signaling. Therefore, with respect to periodic transmission, for example, it is difficult to dynamically change the transmission cycle.

On the other hand, regarding the aperiodic SRS, the eNB sends an SRS request aperiodically as needed, and the UE returns the SRS when the SRS request is received. However, aperiodic SRS is not considered to be suitable as a reference signal for periodically selecting a beam for beam tracking. This is because the downlink SRS request becomes an overhead.

(Relationship between SRS and beam selection)
When the eNB provides a beam to the UE, it is desirable that the eNB selects an appropriate beam for the UE.

As one method for this, as described above with reference to FIGS. 3 and 4, the eNB provides a plurality of beam-formed reference signals, and the beam according to the reception result in the UE is used with the UE. It is conceivable to communicate. In that case, as described above with reference to FIG. 4, the eNB may determine which plurality of beams to transmit the plurality of beam-formed reference signals based on the SRS. This is because the eNB can roughly grasp the direction of the UE based on the reception result of the SRS.

Thus, the SRS can be used for beam selection to provide to the UE. On the other hand, since the SRS is an uplink reference signal, it is difficult for the eNB to know the status of the downlink interference based on the reception result of the SRS. Therefore, the final beam selection should be determined by the UE based on the downlink reference signal.

(Summary)
The SRS has been described above. The points to keep in mind when using SRS for beam tracking are summarized below.

The first point to keep in mind is that the existing SRS mainly aims to acquire channel information of the entire bandwidth in operation. The existing SRS becomes an overhead when only the direction of the beam is known as in beam tracking, and the uplink transmission efficiency may decrease when used for beam tracking.

The second point to note is that neither periodic SRS nor aperiodic SRS is suitable for beam tracking applications. For example, not all UEs require very accurate tracking.

The third point to keep in mind is that it is difficult for SRS to know the status of downlink interference. The final beam selection should be based on the downlink reference signal.

<2.3. Others>
The difficulty of beam tracking will be considered below.

First, it is assumed that the UE does not move at all and is stationary. In that case, beam selection for beam tracking is easy because there is often no change in the beam appropriate for the UE. However, even if the UE is stationary, the beam can be selected again due to the influence of the beam shielding (hereinafter, also referred to as blocking) due to the surrounding environment, for example, a shield such as a car or a human being crossing between the eNB and the UE. It may be done.

In addition, it is assumed that the UE moves at high speed. In that case, since it is necessary to make the beam follow the UE moving at high speed, the difficulty of beam tracking is high. If the beam provided to the UE is sharp, the difficulty of beam tracking will be even higher. For example, when a 1 degree wide beam is provided, the difficulty level is higher than when a 10 degree wide beam is provided, for example. This is because the sharper the beam, the shorter the time it takes for the UE to move within the range included in the beam.

When a discontinuous change in the channel environment occurs regardless of the moving speed of the UE, the difficulty of beam selection becomes high. Changes in the discontinuous channel environment can occur, for example, when a shield suddenly enters between the eNB and the UE, or when the UE in which the antenna is arranged in a plane suddenly rotates. In such cases, the beam appropriate for the UE can change. In addition, it is considered that a beam that reflects and indirectly reaches the UE may be more appropriate than a beam that reaches the UE directly.

<< 3. Configuration example of each device >>
Subsequently, an example of the configuration of each device included in the system 1 according to the embodiment of the present disclosure will be described.

<3.1. Base station configuration example>
FIG. 7 is a block diagram showing an example of the configuration of the base station 100 according to the present embodiment. Referring to FIG. 7, 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 control unit 150.

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

In particular, in the present embodiment, the antenna unit 110 has a plurality of antenna elements and can form a beam.

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

In particular, in the present embodiment, the wireless communication unit 120 can form a plurality of beams by the antenna unit 110 and communicate with the terminal device 200.

(3) Network communication unit 130
The network communication unit 130 transmits / receives information. For example, the network communication unit 130 transmits information to another node and receives information from the other node. For example, the other nodes include other base stations and core network nodes.

(4) Storage unit 140
The storage unit 140 temporarily or permanently stores the program and various data for the operation of the base station 100.

(5) Control unit 150
The control unit 150 provides various functions of the base station 100. The control unit 150 includes a setting unit 151 and a communication control unit 153. The control unit 150 may further include other components other than these components. That is, the control unit 150 can perform operations other than the operations of these components. The operations of the setting unit 151 and the communication control unit 153 will be described in detail later.

<3.2. Terminal device configuration>
FIG. 8 is a block diagram showing an example of the configuration of the terminal device 200 according to the present embodiment. Referring to FIG. 8, the terminal device 200 includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a control unit 240.

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

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

In particular, in the present embodiment, the wireless communication unit 220 can communicate with the base station 100 that forms and communicates with a plurality of beams.

(3) Storage unit 230
The storage unit 230 temporarily or permanently stores the program and various data for the operation of the terminal device 200.

(4) Control unit 240
The control unit 240 provides various functions of the terminal device 200. The control unit 240 includes a setting unit 241 and a communication control unit 243. The control unit 240 may further include other components other than these components. That is, the control unit 240 may perform operations other than the operations of these components. The operations of the setting unit 241 and the communication control unit 243 will be described in detail later.

Hereinafter, the base station 100 is also referred to as an eNB 100, and the terminal device 200 is also referred to as a UE 200.

<< 4. First Embodiment >>
The first embodiment is a mode in which the UE 200 feeds back report information for beam tracking to improve the accuracy of beam tracking by the eNB 100.

<4.1. Technical issues>
(1) Summary of issues It is desirable that the frequency of beam selection is high for moving UEs. On the other hand, it is desirable that the frequency of beam selection is low for UEs that are not moving. This is because as the frequency of beam selection increases, the overhead due to reference signals such as the uplink SRS and the downlink CSI-RS increases, and the system throughput may decrease.

According to the mechanism described above with reference to FIGS. 3 and 4, beam selection is performed based on the SRS and the plurality of beam-formed CSI-RSs. In such a mechanism, it is important that the following four setting items are appropriately set.
-Period of uplink reference signal (eg, SRS) -Selection of beam for beam-formed downlink reference signal (eg, beam-formed CSI-RS) -Number of beam-formed downlink reference signals-Beam Period of Formed Downlink Reference Signal

(2) Uplink Reference Signal The technical issues related to the uplink reference signal will be described below. Scheduling of SRS is done by eNB. SRS is transmitted periodically or aperiodically.

As mentioned above, the eNB sets quasi-statically for periodic SRS. More specifically, the eNB sets a quasi-statically periodic SRS resource, in other words, an SRS period. Therefore, it is difficult for the eNB to flexibly change the SRS cycle according to the moving speed of the UE and the like. That is, it has been difficult to appropriately set the period of the uplink reference signal for beam selection with respect to the periodic SRS.

On the other hand, regarding the aperiodic SRS, as described above, the eNB transmits the SRS request aperiodically. However, if aperiodic SRS is used for beam selection, SRS requests will be made frequently. Therefore, the use of aperiodic SRS for beam selection can be a factor in reducing downlink system throughput. That is, it has been difficult to appropriately set the period of the uplink reference signal for beam selection with respect to the aperiodic SRS.

Regarding such difficulties, for example, a method is conceivable in which the eNB estimates the position and moving speed of the UE based on the reception result of the SRS provided by the UE, and sets resources such as the cycle of the SRS. However, since it takes time to change the SRS setting in this method, beam tracking (that is, selection of an appropriate beam) may not be in time when the moving speed changes suddenly, for example. That is, even with this method, it is difficult to appropriately set the period of the uplink reference signal for beam selection.

Further, since the SRS provided by the UE is typically transmitted by an omnidirectional antenna, collisions can occur between SRS transmitted from different UEs. Therefore, it is desirable for the UE to transmit the SRS using resources that are orthogonal to each other depending on the frequency or time, and it is difficult to make the period of the SRS extremely short.

(3) Beam Formed Downlink Reference Signal Hereinafter, technical problems related to the downlink reference signal will be described with reference to FIGS. 9 to 12. 9 to 12 are diagrams for explaining technical problems related to the downlink reference signal.

As described above with reference to FIG. 4, the eNB grasps the rough position of the UE based on the SRS and selects a plurality of beam candidates suitable for the UE. Then, as shown in FIG. 9, the eNB transmits a plurality of beam-formed CSI-RSs using a plurality of selected beam candidates. In the example shown in FIG. 9, the plurality of beam-formed CSI-RSs are transmitted to the areas 20A to 20G, and the UE is included in the central area 20D. That is, the plurality of beam-formed CSI-RSs roughly capture the UE.

The UE then selects one or more desired beams from the plurality of beams used for transmitting the beam-formed CSI-RS based on the reception results of the plurality of beam-formed CSI-RS provided. , Sends information indicating the selection result to the eNB. For example, in the example shown in FIG. 10, the UE selects a beam destined for area 20D. Then, the eNB selects a beam suitable for the UE based on the information indicating the beam selection result. For example, in the example shown in FIG. 10, the eNB selects a beam destined for area 20D based on feedback from the UE.

Here, the eNB determines whether or not the plurality of beams used for transmitting the plurality of beam-formed CSI-RSs are appropriate, that is, whether or not the beam tracking is successful, based on the information indicating the beam selection result. It is possible to judge. For example, as shown in FIG. 10, when a beam destined for the central area 20D among the plurality of areas 20, that is, the central beam among the plurality of beams is selected, it is determined that the beam tracking is successful. On the other hand, as shown in FIG. 11, when a beam destined for the end area 20E of the plurality of areas 20, that is, the end beam of the plurality of beams is selected, it is determined that the beam tracking is not successful.

However, there is a possibility that an error may occur in the determination of the suitability of beam tracking based on the above-mentioned beam selection result. For example, the UE may select a beam based on SINR (Signal Interference Noise Ratio) in consideration of the amount of interference in consideration of interference received from a beam destined for another UE, interference received from a beam provided by an adjacent eNB, and the like. .. For example, in the example shown in FIG. 12, the UE may consider the interference received from the beam provided by the adjacent eNB even though the beam destined for the area 20D is appropriate from the viewpoint of beam tracking. The beam addressed to the 20th floor is selected. Therefore, although the central beam of the plurality of beam-formed CSI-RS captures the UE and the beam tracking is successful, the eNB determines that the beam tracking is not successful.

Thus, it has sometimes been difficult for the eNB to properly determine whether beam tracking is successful. That is, it is difficult to properly set the beam selection for the beam-formed downlink reference signal, the number of beam-formed downlink reference signals, and the delivery period of the beam-formed downlink reference signals. There was a case.

<4.2. Technical features>
In view of the above technical issues, the present embodiment provides report information for beam tracking. This makes it possible for the eNB 100 to appropriately determine whether or not the beam tracking is successful, and the accuracy of the beam tracking can be improved. Hereinafter, the technical features of the present embodiment will be described.

(1) Two types of report information The eNB 100 (for example, the communication control unit 153) transmits a group of downlink reference signals including a plurality of downlink reference signals transmitted by using a beam to the UE 200. That is, the eNB 100 beam-forms and transmits each of the plurality of downlink reference signals included in the group of downlink reference signals. Such a downlink reference signal that is beam-formed and transmitted is also referred to as a beam-formed downlink reference signal (BF DL RS (Beam Formed Downlink Reference Signal)). The BF DL RS may be, for example, the beam-formed CSI-RS described above, or a plurality of beam-formed CSI-RSs may form a group of BF DL RSs. The eNB 100 uses, for example, a group of beams (ie, a plurality of beams) to transmit a group of downlink reference signals based on the reception result of the uplink reference signal (typically omnidirectional) transmitted from the UE 200. ) May be selected. The uplink reference signal (UL RS (Uplink Reference Signal)) may be, for example, the above-mentioned SRS.

The UE 200 (eg, communication control unit 243) provides first report information for downlink user data regarding the reception result of a group of BF DL RSs including a plurality of BF DL RSs transmitted from the eNB 100 using a beam, and a first report information for downlink user data. The second report information for beam tracking for the UE 200 by the eNB 100 is reported to the eNB 100. Since the second report information for beam tracking is reported separately from the first report information for data communication with the UE 200, the eNB 100 should properly determine whether the beam tracking is successful. Is possible.

For example, the first report information includes information indicating the reception result of a group of BF DL RS in consideration of interference. For example, the first report information is information indicating a beam selection result based on SINR (Signal Interference Noise Ratio) in consideration of the amount of interference such as interference received from a beam destined for another UE 200 and interference from another cell (that is,). Identification information, typically a beam ID). This makes it possible for the eNB 100 to appropriately select the beam used for transmitting user data.

For example, the second report information may include information indicating the reception result of a group of BF DL RSs without considering interference. The second report information can include a variety of information.

For example, the second report information may include information indicating the beam having the highest received power among the group of beams used for transmitting the group of BF DL RS. This makes it possible for the eNB 100 to determine the suitability of beam tracking. For example, the eNB 100 is successful in beam tracking when the beam with the highest received power reported as the second report information is the beam at the center of the group of beams used to transmit the group of BF DL RSs. Judge. On the other hand, in the eNB 100, beam tracking is not successful when the beam with the highest received power reported as the second report information is not the beam at the center of the group of beams used for transmitting the group of BF DL RSs. Judge. This point will be specifically described with reference to FIG.

FIG. 13 is a diagram for explaining the first report information and the second report information according to the present embodiment. As shown in FIG. 13, the eNB 100A transmits a group of BF DL RSs to a plurality of areas 20, and the UE 200 is included in the central area 20D. On the other hand, the UE 200 is receiving interference from the beam transmitted from the eNB 100B. Therefore, the UE 200 reports the beam ID of the beam addressed to the area 20F without interference as the first report information. Further, the UE 200 reports the beam ID of the beam destined for the area 20D having the highest received power of the beam from the eNB 100A as the second report information. The eNB 100A can determine that the beam tracking is successful based on the second report information. Then, the eNB 100A can appropriately select a group of beams for a group of BF DL RS.

In addition, for example, the second report information may include information indicating the suitability of beam tracking by the eNB 100. The information indicating the suitability of beam tracking may be, for example, information indicating whether or not the received power of the beam at the center of a plurality of beams used for transmitting a group of BF DL RSs is the highest. Since the second report information can be expressed by, for example, one bit, it is possible to reduce the uplink overhead.

For example, in an environment in which the UE 200 transmits UL RS for beam tracking by the eNB 100, the second report information may include information requesting a change in the transmission cycle of the UL RS. For example, the second report information may include information that requires the UL RS transmission cycle to be longer or shorter. As a result, the eNB 100 can appropriately set the transmission cycle of the UL RS.

For example, the second report information may include information requesting a change in the number of downlink reference signals in the group. For example, the second report information may include information requiring more or less number of BF DL RSs in a group, in other words, more or less beams used for transmission. This makes it possible for the eNB 100 to appropriately set the number of BF DL RSs.

For example, the second report information may include information requesting a change in the transmission cycle of a group of BF DL RSs. For example, the second report information may include information that requires a longer or shorter transmission cycle for a group of BF DL RSs. This makes it possible for the eNB 100 to appropriately set the transmission cycle of a group of BF DL RSs.

(2) Control based on report information The eNB 100 (for example, setting unit 151) is used for the first report information for downlink user data regarding the reception result of a group of BF DL RS and for beam tracking for UE 200. The reception of the second report information from the UE 200, the first transmission setting based on the first report information, and the second transmission setting based on the second report information are performed.

Specifically, the eNB 100 selects a beam to be used for transmitting user data to the UE 200 as the first transmission setting. As a result, the eNB 100 can transmit user data using a beam having the best SINR in consideration of the amount of interference in the UE 200.

Further, the eNB 100 can make various settings as the second transmission setting.

For example, the eNB 100 may set the transmission cycle of the uplink reference signal transmitted from the UE 200 as the second transmission setting. For example, the eNB 100 can provide a group of BF DL RSs by using a more appropriate beam by setting the transmission cycle of the UL RS to be short, and can improve the accuracy of beam tracking. Further, the eNB 100 can reduce the overhead due to the UL RS by setting the transmission cycle of the UL RS to be long. The eNB 100 may gradually increase the transmission cycle of the UL RS when the beam tracking is successful.

For example, the eNB 100 may set a transmission cycle of a group of BF DL RS as a second transmission setting. For example, the eNB 100 can provide a group of BF DL RSs by using a more appropriate beam by setting the transmission cycle to be short, and can improve the accuracy of beam tracking. Further, the eNB 100 can reduce the overhead due to the group of BF DL RS by setting the transmission cycle to be long.

For example, the eNB 100 may set the number of BF DL RSs included in the group of BF DL RSs as the second transmission setting. For example, the eNB 100 can have a wider area covered by a group of BF DL RSs by setting a large number, and can prevent tracking errors.

For example, the eNB 100 may set a beam to be used for a group of BF DL RS as a second transmission setting. For example, first, the eNB 100 estimates the moving direction of the UE 200 based on the time-series change of the beam selection result included in the second report information. Then, when it is determined that the beam tracking is not successful, the eNB 100 makes settings such as changing the beam used for transmitting a group of BF DL RSs in the estimated moving direction. With such a setting, the eNB 100 can perform beam tracking with higher accuracy.

For example, the eNB 100 may set the sharpness of the beam used for transmitting a group of downlink reference signals as the second transmission setting. For example, the eNB 100 can expand the area covered by one beam by loosening the sharpness of the beam, and can widen the area covered by a group of BF DL RSs, thereby preventing tracking mistakes. it can.

(3) Means for reporting report information There are various possible means for reporting the first report information and the second report information.

For example, the UE 200 (for example, the communication control unit 243) may report the first report information and the second report information as separate messages. Using this mechanism, the UE 200 can select, for example, report information to be reported as needed, or change the reporting cycle. Further, the UE 200 may encode the first report information and the second report information into one message and report the information. In this case, the UE 200 can reduce the uplink overhead. Hereinafter, the reporting timing of the first report information and the second report information will be described with reference to FIGS. 14 to 16.

14 to 16 are diagrams for explaining the reporting timing of the first report information and the second report information according to the present embodiment. In FIGS. 14 to 16, the horizontal axis is the time axis, and the perpendicular lines on the time axis indicate the transmission timings of UL RS, a group of BF DL RS, the first report information, or the second report information. There is. For example, UL RS is transmitted in the transmission cycle indicated by reference numeral 21, a group of BF DL RSs is transmitted in the transmission cycle indicated by reference numeral 22, and the first report information is transmitted in the transmission cycle indicated by reference numeral 23. The second report information is transmitted in the transmission cycle indicated by reference numeral 24. As shown in FIGS. 14 to 16, the transmission cycles of the UL RS and the group of BF DL RSs may be different. Further, as shown in FIGS. 14 and 15, the reporting cycles of the first report information and the second report information may be different. On the other hand, as shown in FIG. 16, the reporting cycles of the first report information and the second report information may be the same.

The UL RS is used to grasp the rough position of the UE, and the group of BF DL RS is used to grasp the exact position of the UE. Therefore, as shown in FIG. 16, the transmission cycle of UL RS is assumed to be longer than the transmission cycle of a group of BF DL RS.

(4) Process Flow The flow of the beam tracking process in the system 1 according to the present embodiment will be described below with reference to FIG.

FIG. 17 is a sequence diagram showing an example of the flow of the beam tracking process executed in the system 1 according to the present embodiment. As shown in FIG. 17, the eNB 100 and the UE 200 are involved in this sequence.

First, the eNB 100 transmits the setting information for the periodic UL RS to the UE 200 (step S102). This setting information includes, for example, information indicating a transmission cycle. Next, the UE 200 transmits the UL RS to the eNB 100 based on the received setting information (step S104). The eNB 100 then estimates the approximate position of the UE 200 based on the received UL RS and sets a group of beams to use for transmitting the group of BF DL RSs to cover the estimated approximate position ( Step S106). Then, the eNB 100 transmits a group of BF DL RSs to the UE 200 using the set group of beams (step S108). Next, the UE 200 transmits the first report information and the second report information to the eNB 100 (steps S110 and S112).

<< 5. Second embodiment >>
The second embodiment is a mode in which blocking resistance is improved by communication using a plurality of beam paths.

<5.1. Technical issues>
When a shield such as a car or a building enters between the eNB and the UE, the beam path suitable for communication may be suddenly lost or the suitable beam path may be suddenly changed. In that case, the UE may fail to receive a group of BF DL RSs transmitted from the eNB, and the continuity of beam tracking may be lost and data communication may be interrupted.

Furthermore, even if the UE fails to receive a group of BF DL RS, it is difficult to identify the cause. Possible causes include, for example, that the received power is small because a group of BF DL RSs are blocked by a shield, and that the received power is small because the beam direction is not directed toward itself. In addition, it has been difficult for the UE to recognize an incomprehensible phenomenon that the originally small received power becomes even smaller, such as when a group of BF DL RSs is blocked by a shield while moving.

Such difficulty increases as the beam becomes sharper. This is because the UE that has fallen out of the range of the beam can hardly receive the power from the beam. Then, when the UE can hardly receive the electric power from the beam, it is difficult to identify the cause.

Even if the cause can be identified, the UE will know that there is a shield, for example, only when it cannot receive the power from the beam destined for itself.

On the other hand, the eNB seems to be able to recognize the presence or absence of a shield when the beam is provided to the UE by preparing a geolocation database or the like and creating a map of the buildings or the like in the cell. However, it is difficult for the eNB to predict the occlusion of the beam by moving obstructions such as humans and automobiles.

<5.2. Technical features>
In view of the above technical problems, the present embodiment provides a plurality of different beam paths, more specifically, not only a beam path using a direct wave but also a beam path using a reflected wave. This makes it possible to improve resistance to blocking. More specifically, even if the beam path using the direct wave is lost, the beam tracking can be continued by using the beam path using the reflected wave. Hereinafter, the technical features of the present embodiment will be described.

In the following, the beam generated by the UE is also referred to as a UE beam, and the beam generated by the eNB is also referred to as an eNB beam.

(1) BF UL RS
Hereinafter, the uplink reference signal transmitted from the UE 200 will be described with reference to FIGS. 18 to 20. 18 to 20 are diagrams for explaining the uplink reference signal according to the present embodiment.

The UE 200 (for example, the communication control unit 243) transmits each of the plurality of uplink reference signals using a UE beam directed in a different direction. That is, the UE 200 transmits each of the plurality of uplink reference signals in a beam form with UE beams directed in different directions. Such an uplink reference signal that is beam-formed and transmitted is also referred to as a beam-formed uplink reference signal (BF UL RS (Beam Formed Uplink Reference Signal)).

As shown in FIG. 18, the UE 200 transmits the BF UL RS31 and 32 in a plurality of directions in which data signals are desired to be diversified from the eNB 100. As a result, the eNB 100 can know the state of reflection around the UE 200, and can transmit the data signal so that the UE 200 can receive the data signal from a plurality of directions accordingly. At this time, the UE 200 transmits the BF UL RS31 using, for example, the first UE beam corresponding to the first direction, and uses the second UE beam corresponding to the second direction to transmit the BF UL RS 32. Send. These UE beams may have lower directivity than the eNB beams. For example, the UE beam may have a half width of about 30 to 60 degrees. Further, the UE 200 does not have to transmit a plurality of BF UL RSs in one direction as in the group of BF DL RSs described above.

Here, as shown in FIG. 19, even when the UE 200 transmits the omnidirectional UL RS33 (for example, SRS), the eNB 100 has passed at least two paths of a direct wave and a reflected wave. UL RS will be received from multiple directions. However, in that case, it is difficult for the eNB 100 to recognize whether the received UL RS from the plurality of directions is via a route in a different direction for the UE 200 or a route in the same direction for the UE 200. Is. It is conceivable that the received UL RS from the plurality of directions passes through the routes in different directions for the UE 200 because the UL RS is reflected by a reflecting object in the vicinity of the UE 200, for example, as shown in FIG. Further, it is conceivable that the received UL RS from the plurality of directions passes through the same direction path for the UE 200 because the UL RS is reflected by a reflecting object in the vicinity of the eNB 100, for example, as shown in FIG. Considering the improvement of resistance to blocking, it is desirable for the UE 200 to transmit the data signal by a beam path passing through different directions. Therefore, an omnidirectional UL RS in which it is difficult for the UE 200 to recognize whether or not the received UL RS from the plurality of directions has passed through routes in different directions is not appropriate in the present embodiment.

The UE 200 transmits each of the plurality of BF UL RSs using resources that are orthogonal to each other at least in time, frequency, or sign. As a result, the eNB 100 can receive each of the plurality of BF UL RSs separately. In the example shown in FIG. 18, resources orthogonal to each other are used in BF UL RS31 and BF UL RS32. On the other hand, in the example shown in FIG. 19, the omnidirectional UL RS33 is transmitted using one resource (that is, a non-orthogonal resource).

Here, as shown in FIG. 20, the UE 200 may transmit each of the plurality of BF UL RSs at different transmission cycles. In FIG. 20, the horizontal axis is the time axis, and the rectangle on the time axis indicates the transmission timing of each of the plurality of BF UL RSs. For example, the BF UL RS31 shown in FIG. 18 is transmitted in the transmission cycle shown in reference numeral 34, and the BF UL RS32 is transmitted in the transmission cycle shown in reference numeral 35. In that case, the signaling corresponding to each BF UL RS is also set to have a different cycle. For example, a short transmission cycle may be set for the BF UL RS having a role as the main, and a long transmission cycle may be set for the BF UL RS having the role as a sub in preparation for blocking.

The UE 200 (for example, the setting unit 241) can set a plurality of UE beams used for transmitting a plurality of BF UL RSs by using various methods. For example, the UE 200 may use the UE beam set by the eNB 100. In that case, for example, the eNB 100 (for example, the setting unit 151) may specify the UE beam to be used in the SRS request for transmitting the aperiodic SRS. Then, the UE 200 may transmit the BF UL RS using the UE beam specified in the SRS request.

(2) Multiple groups of BF DL RS
Hereinafter, the downlink reference signal transmitted from the eNB 100 will be described with reference to FIGS. 21 to 23. 21 to 23 are diagrams for explaining the downlink reference signal according to the present embodiment.

The eNB 100 (eg, communication control unit 153) transmits each of a plurality of groups of downlink reference signals using a group of eNB beams passing through each of a plurality of routes arriving from different directions for the UE 200. Here, the group of downlink reference signals includes a plurality of downlink reference signals transmitted using the eNB beam included in the corresponding group of eNB beams. A group of downlink reference signals transmitted using a group of eNB beams will also be referred to hereinafter as a group of BF DL RSs, and individual downlink reference signals will also be referred to as BF DL RSs. The BF DL RS may be, for example, the beam-formed CSI-RS described above. It is desirable that each of the plurality of groups of BF DL RSs be observable for the UE 200 as received waves arriving from different directions. This is to improve resistance to blocking. Specifically, since multiple sets of BF DL RSs are provided to the UE 200 from different directions, the eNB 100 uses beam tracking with other surviving beam paths, even if some beam paths are lost due to obstruction. Can be continued. For example, the eNB 100 can continue beam tracking using the beam path using the reflected wave even if the beam path using the direct wave is lost.

The eNB 100 transmits a plurality of groups of eNB beams for transmitting a plurality of groups of downlink reference signals based on the reception results of a plurality of BF UL RSs transmitted by the UE 200 using the UE beams directed in a plurality of directions. select. For example, the eNB 100 transmits a group of eNB beams in a direction corresponding to a plurality of received BF UL RSs, typically in a direction of arrival. As a result, the eNB 100 can transmit a group of BF DL RSs by using a group of eNB beams arriving from a plurality of directions that the UE 200 wants to receive diversity.

Such beam selection will be specifically described with reference to FIGS. 21 and 22. First, as shown in FIG. 21, the UE 200 transmits the BF UL RS41 and 42 from the eNB 100 in a plurality of directions in which data signals are desired to be diversified. The eNB 100 then selects a plurality of eNB beams directed in the direction of arrival of the BF UL RS41 and transmits a group of BF DL RS43s using the selected group of eNB beams. Similarly, the eNB 100 selects a plurality of eNB beams directed in the direction of arrival of the BF UL RS42, and transmits a group of BF DL RS44s using the selected group of eNB beams. In FIG. 22, the UE 200 is not shown in order to reduce the complexity.

The eNB 100 transmits each of a plurality of BF DL RSs included in a group of BF DL RSs using resources having the same time and frequency. In addition, the eNB 100 transmits each BF DL RS contained in a group of BF DL RSs in a spatially multiplexed manner (that is, using a different eNB beam). On the other hand, the eNB 100 transmits each of a plurality of groups of BF DL RSs using resources that are orthogonal to each other at least in time or frequency. These allow the UE 200 to determine each group of BF DL RSs based on which quadrature resource was received.

The use of such resources will be specifically described with reference to FIG. For example, as shown in FIG. 23, the eNB 100 transmits each BF DL RS included in the group of BF DL RS43 shown in FIG. 22 by using the resource 45 in common. On the other hand, the eNB 100 transmits each BF DL RS included in the group of BF DL RS 44 shown in FIG. 22 by using the resource 46 in common. The resource 45 and the resource 46 are orthogonal to each other in the time direction.

(3) Report of Report Information Hereinafter, a report of report information for a downlink reference signal from the eNB 100 transmitted from the UE 200 will be described with reference to FIG. 24. FIG. 24 is a diagram for explaining the report of the report information according to the present embodiment.

The UE 200 (for example, the communication control unit 243) of the plurality of groups of BF DL RS transmitted by using each of the plurality of groups of eNB beams selected by the eNB 100 according to the reception result of the plurality of BF UL RS. Information indicating the reception result is reported to the eNB 100. For example, the UE 200 reports to the eNB 100 the information indicating the reception result of the first group of BF DL RS and the information indicating the reception result of the second group of BF DL RS. The information to be reported may be the above-mentioned first report information or the second report information. For example, the reported information is selected from each of the plurality of groups of eNB beams used to transmit the plurality of groups of BF DL RSs to indicate the eNB beam (ie, identification information, typically the beam ID. ) May be included. For example, the UE 200 may report information indicating a first eNB beam selected from a first group of eNB beams used to transmit a first group of BF DL RSs. The UE 200 may also report information indicating a second eNB beam selected from a second group of eNB beams used to transmit a second group of BF DL RSs. As a result, the UE 200 can feed back information indicating a plurality of eNB beams arriving from different directions to the eNB 100, which is a suitable eNB beam addressed to the UE 200.

Then, the eNB 100 (for example, the communication control unit 153) transmits the eNB beam for transmitting the user data to the UE 200 based on the information reported from the UE 200 indicating the reception result of a plurality of groups of BF DL RSs in the UE 200. , Select from each of the plurality of groups of eNB beams used to transmit the plurality of groups of BF DL RS. For example, the eNB 100 selects a plurality of eNB beams indicated by a plurality of identification information fed back from the UE 200, and transmits a data signal including user data using the plurality of eNB beams. This allows the UE 200 to receive data signals from different directions for the UE 200. At that time, the eNB 100 transmits the same user data to the UE 200 using the plurality of selected eNB beams. This makes it possible to obtain a diversity gain in the spatial direction. That is, even if a part of the beam paths is suddenly lost, the UE 200 can continuously receive user data from the other surviving beam paths, which can reduce the probability of communication interruption. It will be possible.

Such transmission of user data using a plurality of beam paths will be specifically described with reference to FIG. 24. For example, as shown in FIG. 24, the eNB 100 was used to transmit a group of BF DL RS43s selected based on the information reported by the UE 200 indicating the reception results of the group of BF DL RS43s shown in FIG. A data signal 47 is transmitted using an eNB beam included in a group of eNB beams. Further, the eNB 100 is included in the group of eNB beams used for transmitting the group of BF DL RS44 selected based on the information indicating the reception result of the group of BF DL RS44 shown in FIG. 22 reported from the UE 200. A data signal 48 is transmitted using the eNB beam.

(4) Process Flow The series of process flows described above will be described with reference to FIG. 25.

FIG. 25 is a sequence diagram showing an example of the flow of communication processing executed in the system 1 according to the present embodiment. As shown in FIG. 25, the eNB 100 and the UE 200 are involved in this sequence. Further, in this sequence, an example in which the BF UL RS is transmitted in two directions will be described. Of course, the number of transmitted directions is arbitrary.

As shown in FIG. 25, first, the eNB 100 transmits the setting information for the BF UL RS to the UE 200 (step S202). This setting information may include, for example, information indicating a UE beam to be used for transmission of BF UL RS, information indicating a resource to be used, a transmission cycle, and the like.

The UE 200 then transmits the first BF UL RS beam-formed by the first UE beam to the eNB 100 (step S204). Further, the UE 200 transmits the second BF UL RS beam-formed by the second UE beam to the eNB 100 (step S206).

Next, the eNB 100 sets a plurality of groups of eNB beams used for transmitting a plurality of groups of BF DL RS (step S208). For example, the eNB 100 selects a first group of eNB beams corresponding to the first BF UL RS and a second group of eNB beams corresponding to the second BF UL RS.

The eNB 100 then transmits the first group of BF DL RS beam-formed by the selected first group of eNB beams to the UE 200 (step S210). Further, the eNB 100 transmits a second group of BF DL RS beam-formed by the selected second group of eNB beams to the UE 200 (step S212).

Next, the UE 200 transmits the report information regarding the BF DL RS of the first group to the eNB 100 as the information indicating the reception result of the BF DL RS of the first group (step S214). Further, the UE 200 transmits the report information regarding the second group of BF DL RS to the eNB 100 as the information indicating the reception result of the second group of BF DL RS (step S216).

Then, the eNB 100 sets a plurality of eNB beams used for transmitting user data (step S218). For example, the eNB 100 selects the first eNB beam included in the first group of eNB beams based on the information indicating the reception result of the first group of BF DL RS. Further, the eNB 100 selects the second eNB beam included in the second group of eNB beams based on the information indicating the reception result of the second group of BF DL RS. The eNB 100 then transmits a data signal containing user data beam-formed by the selected first eNB beam to the UE 200 (step S220). Further, the eNB 100 transmits a data signal including user data beam-formed by the selected second eNB beam to the UE 200 (step S222).

<5.3. Modification example>
-Summary When the UE transmits an omnidirectional UL RS to the eNB, the eNB can receive the UL RS even if blocking occurs due to a shield entering between the UE and the eNB. is there. Therefore, when reciprocity is established between UL and DL by adopting TDD, and when the UE continues to transmit omnidirectional UL RS to eNB with high frequency, eNB is based on the reception result of UL RS. It is possible to continue to provide the appropriate eNB beam to the UE.

However, transmitting omnidirectional UL RS at high frequency means an increase in the ratio of UL RS to UL resources, which causes an increase in UL overhead and a decrease in throughput. Therefore, in the present embodiment, as described above, the UE 200 transmits a plurality of BF UL RSs. As a result, the frequency of transmission of UL RS can be reduced, so that it is possible to avoid or reduce an increase in UL overhead and a decrease in throughput.

However, a method of transmitting omnidirectional UL RS with high frequency is effective as a countermeasure against blocking. Therefore, in this modification, we provide a technique that improves the method of transmitting omnidirectional UL RS with high frequency.

-Technical features The technical features of this modification will be described below.

As described above, the UE 200 transmits a plurality of BF UL RSs in different directions. Further, as described above, the eNB 100 selects a plurality of groups of eNB beams based on the reception results of the plurality of BF UL RSs, and transmits the plurality of groups of BF DL RSs. Next, as described above, the UE 200 feeds back the information indicating the reception result of the plurality of groups of BF DL RS to the eNB 100.

In the above, the information indicating the reception result of the plurality of groups of BF DL RS to be fed back is selected from each of the plurality of groups of eNB beams used for the transmission of the plurality of groups of BF DL RS, and is suitable eNB. It contained information indicating the beam.

On the other hand, in this modification, the information indicating the reception result of the plurality of groups of BF DL RS includes the information indicating the reception quality of the group of BF DL RS. For example, the information indicating the reception quality may be information indicating a group of eNB beams having poor reception quality, that is, blocking has occurred or is likely to occur. That is, this feedback does not notify the desired eNB beam candidates, nor does it notify the undesired eNB beam, but informs the eNB 100 that blocking is occurring or is likely to occur. .. To that end, the UE 200 (eg, communication control unit 243) identifies a group of eNB beams in which blocking has occurred or is likely to occur, based on the reception results of the plurality of groups of BF DL RSs. Then, the UE 200 feeds back the information indicating the specified group of eNB beams to the eNB 100. The reception quality here may be, for example, the received power. Hereinafter, information indicating a group of eNB beams in which blocking has occurred or is likely to occur is also referred to as blocking information.

It should be noted that the identification of a group of eNB beams in which blocking has occurred or is likely to occur may be performed in the eNB 100. In that case, the eNB 100 contains information indicating the reception quality of each of the plurality of groups of BF DL RSs.

The eNB 100 (for example, the communication control unit 153) is a group of a plurality of groups used for transmitting a plurality of groups of BF DL RSs based on information indicating the reception quality of the group of BF DL RSs (typically, blocking information). The eNB beam may be changed. This allows the eNB 100 to stop using a group of eNB beams that have or are likely to have blocking and switch to another group of eNB beams. Therefore, it is possible to prevent the occurrence of blocking in advance, or to eliminate the blocking immediately after the occurrence of blocking.

In order for the eNB 100 to switch a group of eNB beams, it is desirable that a group of switching candidate eNB beams is prepared in advance. For example, the eNB 100 prepares a large number of groups of eNB beams in advance, uses a part of them to transmit a group of BF DL RS, and switches the group of eNB beams to be used according to feedback. The flow of such processing will be specifically described with reference to FIG.

FIG. 26 is a sequence diagram showing an example of the flow of communication processing executed in the system 1 according to this modification. As shown in FIG. 26, the eNB 100 and the UE 200 are involved in this sequence. Further, in this sequence, an example in which the BF UL RS is transmitted in three directions and a group of BF DL RSs are transmitted in two directions will be described. Of course, the number of transmitted directions is arbitrary.

As shown in FIG. 26, first, the eNB 100 transmits the setting information for the BF UL RS to the UE 200 (step S302). This setting information may include, for example, information indicating a UE beam to be used for transmission of BF UL RS, information indicating a resource to be used, a transmission cycle, and the like.

The UE 200 then transmits the first BF UL RS beam-formed by the first UE beam to the eNB 100 (step S304). Further, the UE 200 transmits the second BF UL RS beam-formed by the second UE beam to the eNB 100 (step S306). Further, the UE 200 transmits a third BF UL RS beam-formed by the third UE beam to the eNB 100 (step S308).

Next, the eNB 100 sets a plurality of groups of eNB beams used for transmitting a plurality of groups of BF DL RS (step S310). For example, the eNB 100 selects a first group of eNB beams corresponding to the first BF UL RS and a second group of eNB beams corresponding to the second BF UL RS.

The eNB 100 then transmits the first group of BF DL RS beam-formed by the selected first group of eNB beams to the UE 200 (step S312). Further, the eNB 100 transmits a second group of BF DL RS beam-formed by the selected second group of eNB beams to the UE 200 (step S314).

Next, the UE 200 transmits blocking information to the eNB 100 as information indicating the reception results of the plurality of received BF DL RSs (step S316). This blocking information includes, for example, information indicating that blocking has occurred or is likely to occur in the second group of eNB beams.

Then, the eNB 100 resets the plurality of groups of eNB beams used for transmitting the plurality of groups of BF UL RS based on the blocking information (step S318). For example, the eNB 100 reselects the first group of eNB beams as the plurality of groups of eNB beams used for transmitting the plurality of groups of BF UL RS, and further replaces the second group of eNB beams with a third group of eNB beams. Select a group of eNB beams.

The eNB 100 then transmits the first group of BF DL RS beam-formed by the selected first group of eNB beams to the UE 200 (step S320). Further, the eNB 100 transmits the BF DL RS of the third group beam-formed by the selected third group of eNB beams to the UE 200 (step S322).

<< 6. 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 kind of eNB (evolved Node B) such as a macro eNB or a small eNB. The small eNB may be an eNB that covers cells smaller than the 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 NodeB or BTS (Base Transceiver Station). The base station 100 may include a main body (also referred to as a base station device) that controls wireless communication, and one or more RRHs (Remote Radio Heads) that are arranged at a location different from the main body. Further, various types of terminals, which will be described later, may operate as the base station 100 by temporarily or semi-permanently executing the base station function.

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. Further, 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. Further, the terminal device 200 may be a wireless communication module (for example, an integrated circuit module composed of one die) mounted on these terminals.

<6.1. Application examples related to base stations>
(First application example)
FIG. 27 is a block diagram showing a first example of a schematic configuration of an eNB to which the techniques according to the present disclosure can be applied. The eNB 800 has one or more antennas 810 and a base station device 820. Each antenna 810 and base station device 820 may be connected to each other via an RF cable.

Each of the antennas 810 has a single antenna element or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna) and is used for transmitting and receiving a radio signal by the base station apparatus 820. The eNB 800 has a plurality of antennas 810 as shown in FIG. 27, and the plurality of antennas 810 may correspond to a plurality of frequency bands used by the eNB 800, for example. Although FIG. 27 shows an example in which the eNB 800 has a plurality of antennas 810, the eNB 800 may have 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, for example, a CPU or a DSP, 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 transfer the generated bundled packet. Further, the controller 821 is a logic that executes control such as radio resource control (Radio Resource Control), radio bearer control (Radio Bearer Control), mobility management (Mobility Management), inflow control (Admission Control), or scheduling (Scheduling). Function. Further, the control may be executed in cooperation with the surrounding eNB or the core network node. The memory 822 includes a RAM and a ROM, and stores a program executed by the controller 821 and various control data (for example, terminal list, transmission power data, scheduling data, etc.).

The network interface 823 is a communication interface for connecting the base station apparatus 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 other eNB may be connected to each other by a logical interface (for example, S1 interface or X2 interface). The network interface 823 may be a wired communication interface or a wireless communication interface for a 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 either a cellular communication method such as LTE (Long Term Evolution) or LTE-Advanced, and provides a wireless connection to a terminal 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, coding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and may perform each layer (for example, L1, MAC (Medium Access Control), RLC (Radio Link Control), and PDCP. (Packet Data Convergence Protocol)) Performs various signal processing. The BB processor 826 may have some or all of the above-mentioned logical functions instead of the controller 821. The BB processor 826 may be a module including a memory for storing a communication control program, a processor for executing the program, and related circuits, and the function of the BB processor 826 may be changed by updating the above program. Good. Further, the module may be a card or a blade inserted into the slot of the base station device 820, or may be 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 radio signals via the antenna 810.

The wireless communication interface 825 includes a plurality of BB processors 826 as shown in FIG. 27, and the plurality of BB processors 826 may correspond to a plurality of frequency bands used by, for example, the eNB 800. Further, the wireless communication interface 825 includes a plurality of RF circuits 827 as shown in FIG. 27, and the plurality of RF circuits 827 may correspond to, for example, a plurality of antenna elements. Although FIG. 27 shows 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. It may be.

In the eNB 800 shown in FIG. 27, one or more components (setting unit 151 and / or communication control unit 153) included in the control unit 150 described with reference to FIG. 7 are implemented in the wireless communication interface 825. May be good. Alternatively, at least some of these components may be implemented in the controller 821. As an example, the eNB 800 may include a module including a part (for example, a BB processor 826) or all of the wireless communication interface 825 and / or a controller 821, and the module may be equipped with one or more of the above components. Good. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components). You may run the program. As another example, even if a program for making the processor function as one or more of the above components is installed in the eNB 800 and the wireless communication interface 825 (eg, BB processor 826) and / or the controller 821 executes the program. Good. As described above, the eNB 800, the base station device 820, or the module may be provided as a device including the one or more components, and a program for making the processor function as the one or more components is provided. You may. Further, a readable recording medium on which the above program is recorded may be provided.

Further, in the eNB 800 shown in FIG. 27, the wireless communication unit 120 described with reference to FIG. 7 may be mounted in the wireless communication interface 825 (for example, RF circuit 827). Further, the antenna unit 110 may be mounted on the antenna 810. Further, the network communication unit 130 may be implemented in the controller 821 and / or the network interface 823. Further, the storage unit 140 may be mounted in the memory 822.

(Second application example)
FIG. 28 is a block diagram showing a second example of a schematic configuration of an eNB to which the techniques according to the present disclosure can be applied. The eNB 830 has one or more antennas 840, a base station device 850, and an RRH860. Each antenna 840 and RRH860 may be connected to each other via an RF cable. Further, the base station apparatus 850 and RRH860 may be connected to each other by a high-speed line such as an optical fiber cable.

Each of the antennas 840 has a single or multiple antenna elements (eg, a plurality of antenna elements constituting a MIMO antenna) and is used for transmitting and receiving radio signals by the RRH860. The eNB 830 has a plurality of antennas 840 as shown in FIG. 28, and the plurality of antennas 840 may correspond to a plurality of frequency bands used by the eNB 830, for example. Although FIG. 28 shows an example in which the eNB 830 has a plurality of antennas 840, the eNB 830 may have a single antenna 840.

The base station apparatus 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 similar to the controller 821, the memory 822, and the network interface 823 described with reference to FIG. 27.

The wireless communication interface 855 supports either a cellular communication method such as LTE or LTE-Advanced, and provides a wireless connection to terminals located in the sector corresponding to the RRH860 via the RRH860 and the antenna 840. The wireless communication interface 855 may typically include a BB processor 856 and the like. The BB processor 856 is similar to the BB processor 826 described with reference to FIG. 27, except that it is connected to the RF circuit 864 of the RRH860 via the connection interface 857. The wireless communication interface 855 includes a plurality of BB processors 856 as shown in FIG. 28, and the plurality of BB processors 856 may correspond to a plurality of frequency bands used by, for example, the eNB 830. Although FIG. 28 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 RRH860. 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 RRH860.

The RRH860 also includes a connection interface 861 and a wireless communication interface 863.

The connection interface 861 is an interface for connecting the RRH860 (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 RF circuits 864 and the like. The RF circuit 864 may include a mixer, a filter, an amplifier, and the like, and transmits and receives radio signals via the antenna 840. The wireless communication interface 863 includes a plurality of RF circuits 864 as shown in FIG. 28, and the plurality of RF circuits 864 may correspond to, for example, a plurality of antenna elements. Although FIG. 28 shows 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 shown in FIG. 28, one or more components (setting unit 151 and / or communication control unit 153) included in the control unit described with reference to FIG. 7 are wireless communication interfaces 855 and / or wireless communication. It may be implemented in interface 863. Alternatively, at least some of these components may be implemented in controller 851. As an example, the eNB 830 includes a module including a part (for example, BB processor 856) or all of the wireless communication interface 855 and / or a controller 851, and even if one or more of the above components are implemented in the module. Good. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components). You may run the program. As another example, even if a program for making the processor function as one or more of the above components is installed in the eNB 830 and the wireless communication interface 855 (eg, BB processor 856) and / or the controller 851 executes the program. Good. As described above, the eNB 830, the base station device 850, or the module may be provided as a device including the one or more components, and a program for making the processor function as the one or more components is provided. You may. Further, a readable recording medium on which the above program is recorded may be provided.

Further, in the eNB 830 shown in FIG. 28, for example, the wireless communication unit 120 described with reference to FIG. 7 may be mounted on the wireless communication interface 863 (for example, RF circuit 864). Further, the antenna unit 110 may be mounted on the antenna 840. Further, the network communication unit 130 may be implemented in the controller 851 and / or the network interface 853. Further, the storage unit 140 may be mounted in the memory 852.

<6.2. Application examples related to terminal devices>
(First application example)
FIG. 29 is a block diagram showing 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, and one or more antenna switches 915. It comprises one or more antennas 916, bus 917, battery 918 and auxiliary controller 919.

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. Memory 902 includes RAM and ROM and stores programs and data executed by processor 901. The storage 903 may 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 has an image pickup device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and generates an captured image. The sensor 907 may include, for example, a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor and an acceleration sensor. The microphone 908 converts the voice input to the smartphone 900 into a voice signal. The input device 909 includes, for example, a touch sensor, a keypad, a keyboard, a button, or a switch for detecting a touch on the screen of the display device 910, and receives an operation or information input from the 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 the voice signal output from the smartphone 900 into voice.

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, coding / decoding, modulation / demodulation, multiplexing / demultiplexing, and the like, 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 a BB processor 913 and an 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 shown in FIG. Although FIG. 29 shows an example in which the wireless communication interface 912 includes a plurality of BB processors 913 and a plurality of RF circuits 914, the wireless communication interface 912 includes a single BB processor 913 or a single RF circuit 914. It may be.

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

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

Each of the antennas 916 has a single or multiple antenna elements (eg, a plurality of antenna elements constituting a MIMO antenna) and is used for transmitting and receiving radio signals by the wireless communication interface 912. The smartphone 900 may have a plurality of antennas 916 as shown in FIG. Although FIG. 29 shows an example in which the smartphone 900 has a plurality of antennas 916, the smartphone 900 may have a single antenna 916.

Further, the smartphone 900 may be provided with 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, the memory 902, the storage 903, the external connection interface 904, the camera 906, the sensor 907, the microphone 908, the input device 909, the display device 910, the speaker 911, the wireless communication interface 912, and the auxiliary controller 919 to each other. .. The battery 918 supplies electric power to each block of the smartphone 900 shown in FIG. 29 via a power supply line partially shown by a broken line in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900, for example, in the sleep mode.

In the smartphone 900 shown in FIG. 29, one or more components (setting unit 241 and / or communication control unit 243) included in the control unit 240 described with reference to FIG. 8 are implemented in the wireless communication interface 912. You may. Alternatively, at least some of these components may be implemented in processor 901 or auxiliary controller 919. As an example, the smartphone 900 includes a module including a part (for example, BB processor 913) or all of the wireless communication interface 912, a processor 901, and / or an auxiliary controller 919, and one or more of the above-mentioned components in the module. May be implemented. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components). You may run the program. As another example, a program for making the processor function as one or more of the above components is installed in the smartphone 900, the wireless communication interface 912 (eg, BB processor 913), the processor 901, and / or the auxiliary controller 919. You may run the program. As described above, the smartphone 900 or the module may be provided as a device including the one or more components, or a program for making the processor function as the one or more components may be provided. Further, a readable recording medium on which the above program is recorded may be provided.

Further, in the smartphone 900 shown in FIG. 29, for example, the wireless communication unit 220 described with reference to FIG. 8 may be mounted on the wireless communication interface 912 (for example, RF circuit 914). Further, the antenna unit 210 may be mounted on the antenna 916. Further, the storage unit 230 may be mounted in the memory 902.

(Second application example)
FIG. 30 is a block diagram showing an example of a schematic configuration of a car navigation device 920 to which the technique 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. It comprises an interface 933, one or more antenna switches 936, one or more antennas 937, and a battery 938.

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

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

The content player 927 reproduces the content stored in the storage medium (for example, a 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 accepts 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 an image of a navigation function or a content to be reproduced. The speaker 931 outputs the sound of the navigation function or the content to be played.

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, coding / decoding, modulation / demodulation, multiplexing / demultiplexing, and the like, 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 radio signals via the antenna 937. The wireless communication interface 933 may be a one-chip module in which a BB processor 934 and an 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. Although FIG. 30 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. It may be.

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

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

Each of the antennas 937 has a single or multiple antenna elements (eg, a plurality of antenna elements constituting a MIMO antenna) and is used for transmitting and receiving radio signals by the wireless communication interface 933. The car navigation device 920 may have a plurality of antennas 937 as shown in FIG. Although FIG. 30 shows an example in which the car navigation device 920 has a plurality of antennas 937, the car navigation device 920 may have a single antenna 937.

Further, the car navigation device 920 may be provided with an antenna 937 for each wireless communication system. In that case, the antenna switch 936 may be omitted from the configuration of the car navigation device 920.

The battery 938 supplies electric power to each block of the car navigation device 920 shown in FIG. 30 via a power supply line partially shown by a broken line in the figure. In addition, the battery 938 stores electric power supplied from the vehicle side.

In the car navigation device 920 shown in FIG. 30, one or more components (setting unit 241 and / or communication control unit 243) included in the control unit 240 described with reference to FIG. 8 are included in the wireless communication interface 933. It may be implemented. Alternatively, at least some of these components may be implemented in processor 921. As an example, the car navigation device 920 includes a module including a part (for example, BB processor 934) or all and / or a processor 921 of the wireless communication interface 933, in which one or more of the above components are mounted. You may. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components). You may run the program. As another example, a program for making the processor function as one or more of the above components is installed in the car navigation device 920, and the wireless communication interface 933 (eg, BB processor 934) and / or the processor 921 executes the program. You may. As described above, the car navigation device 920 or the module may be provided as a device including the one or more components, or a program for making the processor function as the one or more components may be provided. Good. Further, a readable recording medium on which the above program is recorded may be provided.

Further, in the car navigation device 920 shown in FIG. 30, for example, the wireless communication unit 220 described with reference to FIG. 8 may be mounted on the wireless communication interface 933 (for example, RF circuit 935). Further, the antenna unit 210 may be mounted on the antenna 937. Further, the storage unit 230 may be mounted in the memory 922.

Further, the technique 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. 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 vehicle-mounted network 941.

<< 7. Summary >>
As described above, one embodiment of the present disclosure has been described in detail with reference to FIGS. 1 to 30. As described above, according to the first embodiment, the UE 200 communicates with the eNB 100 that forms and communicates with a plurality of beams, and the downlink user regarding the reception result of a group of BF DL RS transmitted from the eNB 100. The first report information for the data and the second report information for beam tracking for the UE 200 by the eNB 100 are reported to the eNB 100. As a result, the eNB 100 can appropriately select the beam to be used for transmitting the user data, and can appropriately determine whether or not the beam tracking is successful. In this way, since it is appropriately determined in the eNB 100 whether or not the beam tracking is successful, the accuracy of the beam tracking is improved, and the continuity of the beam tracking is improved accordingly.

Further, according to the second embodiment, the UE 200 forms a plurality of beams to communicate with the eNB 100, and transmits each of the plurality of BF UL RSs using beams directed in different directions. Then, the eNB 100 transmits each of the plurality of groups of BF RL RSs to the UE 200 using a group of beams via each of the plurality of routes arriving from different directions based on the reception results of the plurality of BF UL RSs. To do. Therefore, the eNB 100 can continue beam tracking using other surviving beam paths even if a part of the beam paths is lost, for example. In this way, the resistance to blocking is improved, and the continuity of beam tracking is improved accordingly.

Although the preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field of the present disclosure can come up with various modifications or modifications within the scope of the technical ideas described in the claims. Of course, it is understood that the above also belongs to the technical scope of the present disclosure.

For example, the techniques described above may be combined as appropriate. For example, each of the above embodiments can be combined.

Further, the processes described with reference to the flowchart and the sequence diagram in the present specification do not necessarily have to be executed in the order shown in the drawings. Some processing steps may be performed in parallel. Further, additional processing steps may be adopted, and some processing steps may be omitted.

In addition, the effects described herein are merely explanatory or exemplary and are not limited. That is, the techniques according to the present disclosure may exhibit other effects apparent to those skilled in the art from the description herein, in addition to or in place of the above effects.

The following configurations also belong to the technical scope of the present disclosure.
(1)
It ’s a terminal device,
A communication unit that communicates with a base station that forms multiple beams and communicates with
First report information for downlink user data regarding the reception result of a group of downlink reference signals including a plurality of downlink reference signals transmitted from the base station using a beam, and the terminal device by the base station. A control unit that reports a second report information for beam tracking to the base station,
A terminal device comprising.
(2)
The first report information includes information indicating the reception result of the group of downlink reference signals in consideration of interference.
The terminal device according to (1) above, wherein the second report information includes information indicating a reception result of the group of downlink reference signals without considering interference.
(3)
The terminal device according to (2) above, wherein the second report information includes information indicating a beam having the highest received power among the group of beams used for transmitting the group of downlink reference signals.
(4)
The terminal device according to (2) or (3) above, wherein the second report information includes information indicating the suitability of beam tracking by the base station.
(5)
The control unit transmits an uplink reference signal for beam tracking by the base station.
The terminal device according to any one of (2) to (4) above, wherein the second report information includes information requesting a change in the transmission cycle of the uplink reference signal.
(6)
The terminal according to any one of (2) to (5) above, wherein the second report information includes information requesting a change in the number of downlink reference signals included in the group of downlink reference signals. apparatus.
(7)
The terminal device according to any one of (2) to (6) above, wherein the second report information includes information requesting a change in the transmission cycle of the group of downlink reference signals.
(8)
The terminal device according to any one of (1) to (7) above, wherein the control unit reports the first report information and the second report information as separate messages.
(9)
The terminal device according to any one of (1) to (7) above, wherein the control unit encodes the first report information and the second report information into one message and reports the information.
(10)
A communication unit that forms multiple beams and communicates with the terminal device,
First report information for downlink user data relating to transmission of a group of downlink reference signals including a plurality of downlink reference signals transmitted using a beam to the terminal device, reception results of the group of downlink reference signals. And the reception of the second report information for beam tracking for the terminal device from the terminal device, the first transmission setting based on the first report information, and the second report information based on the second report information. The control unit that sets the transmission of 2 and
Base station with.
(11)
The base station according to (10) above, wherein the control unit selects a beam to be used for transmitting user data to the terminal device as the first transmission setting.
(12)
The base station according to (10) or (11), wherein the control unit sets a transmission cycle of an uplink reference signal transmitted from the terminal device as the second transmission setting.
(13)
The base station according to any one of (10) to (12) above, wherein the control unit sets a transmission cycle of a beam used for transmitting the group of downlink reference signals as the second transmission setting. ..
(14)
The base station according to any one of (10) to (13) above, wherein the control unit sets the number of beams used for transmitting the group of downlink reference signals as the second transmission setting.
(15)
The base station according to any one of (10) to (14) above, wherein the control unit sets a beam to be used for transmitting the group of downlink reference signals as the second transmission setting.
(16)
The base station according to any one of (10) to (15) above, wherein the control unit sets the sharpness of the beam used for transmitting the group of downlink reference signals as the second transmission setting.
(17)
A communication unit that forms multiple beams and communicates with the base station,
A control unit that transmits each of a plurality of uplink reference signals using beams directed in different directions,
A terminal device comprising.
(18)
The control unit receives a reception result of a plurality of groups of downlink reference signals transmitted by using each of the plurality of groups of beams selected by the base station according to the reception results of the plurality of uplink signals. The terminal device according to (17) above, which reports the indicated information to the base station.
(19)
The information indicating the reception result of the plurality of groups of downlink reference signals includes information indicating a beam selected from each of the plurality of groups of beams used for transmitting the plurality of groups of downlink reference signals. The terminal device according to (18) above.
(20)
The terminal device according to (18) above, wherein the information indicating the reception result of the plurality of groups of downlink reference signals includes information indicating the reception quality of the group of downlink reference signals.
(21)
The control unit transmits each of the plurality of uplink reference signals using resources that are orthogonal to each other at least in time, frequency, or sign, according to any one of (17) to (20). The terminal device described.
(22)
The terminal device according to any one of (17) to (21), wherein the control unit transmits each of the plurality of uplink reference signals at different transmission cycles.
(23)
A communication unit that forms multiple beams and communicates with the terminal device,
A control unit that transmits each of a plurality of groups of downlink reference signals using a group of beams that pass through each of a plurality of paths arriving from different directions for the terminal device.
A base station equipped with.
(24)
The control unit selects a plurality of the group of beams based on the reception results of a plurality of uplink reference signals transmitted by the terminal device using beams directed in a plurality of directions, according to the above (23). Base station.
(25)
The base according to (23) or (24) above, wherein the control unit transmits each of a plurality of downlink reference signals included in the group of downlink reference signals using resources having the same time and frequency. Station.
(26)
The control unit transmits each of the plurality of groups of downlink reference signals using resources that are orthogonal to each other at least in time or frequency, according to any one of (23) to (25). The listed base station.
(27)
The control unit emits a beam for transmitting user data to the terminal device based on the information indicating the reception result of the plurality of groups of downlink reference signals in the terminal device, and the plurality of groups of downlink references. The base station according to any one of (23) to (26) above, which is selected from each of a plurality of each group of beams used for transmitting a signal.
(28)
The base station according to (27), wherein the control unit transmits the same user data to the terminal device using a plurality of selected beams.
(29)
Communicating with base stations that form multiple beams and communicate with each other
The first report information for downlink user data regarding the reception result of a group of downlink reference signals including a plurality of downlink reference signals transmitted from the base station using a beam, and the terminal device by the base station. To report the second report information for the targeted beam tracking to the base station by the processor, and
How to include.
(30)
Computer,
A communication unit that communicates with a base station that forms multiple beams and communicates with
The first report information for downlink user data regarding the reception result of a group of downlink reference signals including a plurality of downlink reference signals transmitted from the base station using a beam, and the terminal device by the base station. A control unit that reports the second report information for target beam tracking to the base station, and
A recording medium on which a program for functioning as is recorded.
(31)
Forming multiple beams to communicate with the terminal device,
First report information for downlink user data relating to transmission of a group of downlink reference signals including a plurality of downlink reference signals transmitted using a beam to the terminal device, reception results of the group of downlink reference signals. And the reception of the second report information for beam tracking for the terminal device from the terminal device, the first transmission setting based on the first report information, and the second report information based on the second report information. Setting the transmission of 2 by the processor and
How to include.
(32)
Computer,
A communication unit that forms multiple beams and communicates with the terminal device,
First report information for downlink user data relating to transmission of a group of downlink reference signals including a plurality of downlink reference signals transmitted using a beam to the terminal device, reception results of the group of downlink reference signals. And the reception of the second report information for beam tracking for the terminal device from the terminal device, the first transmission setting based on the first report information, and the second report information based on the second report information. The control unit that sets the transmission of 2 and
A recording medium on which a program for functioning as is recorded.
(33)
Forming multiple beams to communicate with the base station,
Transmitting each of the multiple uplink reference signals by the processor with beams directed in different directions,
How to include.
(34)
Computer,
A communication unit that forms multiple beams and communicates with the base station,
A control unit that transmits each of a plurality of uplink reference signals using beams directed in different directions,
A recording medium on which a program for functioning as is recorded.
(35)
Forming multiple beams to communicate with the terminal device,
Each of the plurality of sets of downlink reference signals is transmitted by the processor using a group of beams passing through each of the plurality of paths arriving from different directions for the terminal device.
How to include.
(36)
Computer,
A communication unit that forms multiple beams and communicates with the terminal device,
A control unit that transmits each of a plurality of groups of downlink reference signals using a group of beams that pass through each of a plurality of paths arriving from different directions for the terminal device.
A recording medium on which a program for functioning as is recorded.

1 System 100 Base station 110 Antenna unit 120 Wireless communication unit 130 Network communication unit 140 Storage unit 150 Control unit 151 Setting unit 153 Communication control unit 200 Terminal equipment 210 Antenna unit 220 Wireless communication unit 230 Storage unit 240 Control unit 241 Setting unit 243 Communication Control unit

Claims (14)

A communication unit that forms multiple UE beams in each of multiple directions and communicates with the base station.
A control unit that transmits each of a plurality of uplink reference signals using a UE beam directed in different directions,
With
The communication unit receives each of the plurality of groups of downlink reference signals transmitted using the plurality of groups of eNB beams selected by the base station according to the reception result of the plurality of uplink reference signals. And
The control unit reports to the base station information indicating the reception result of the plurality of groups of downlink reference signals.
The communication unit is a terminal device that receives data transmitted using each of the plurality of groups of eNB beams selected by the base station according to the reception result of the plurality of groups of downlink reference signals. The information indicating the reception result of the plurality of groups of downlink reference signals includes information indicating a beam selected from each of the plurality of groups of eNB beams used for transmitting the plurality of groups of downlink reference signals. The terminal device according to claim 1, which includes. Information indicating the reception result of the plurality of a group of downlink reference signal includes information indicating the reception quality of the set of downlink reference signal, the terminal device according to claim 1. The terminal according to any one of claims 1 to 3 , wherein the control unit transmits each of the plurality of uplink reference signals using resources that are orthogonal to each other at least in time, frequency, or sign. apparatus. The terminal device according to any one of claims 1 to 4 , wherein the control unit transmits each of the plurality of uplink reference signals at different transmission cycles. To form a group of eNB beam passing through each of the plurality of paths arriving from different directions for the terminal device in communication with the terminal device, and transmits using a plurality of UE beams said terminal device is directed to a plurality of directions A communication unit that receives multiple uplink reference signals,
Each of the plurality of groups of downlink reference signals selected according to the reception result of the plurality of uplink reference signals is used as a group of eNB beams passing through each of the plurality of paths arriving from different directions for the terminal device. And the control unit to send
With
The communication unit receives information indicating the reception result of the plurality of groups of downlink reference signals from the terminal device.
The control unit selects a plurality of groups of eNB beams according to the reception results of the plurality of uplink reference signals.
The communication unit is a base station that transmits data to the terminal device using each of a plurality of selected groups of eNB beams. The base station according to claim 6 , wherein the control unit transmits each of a plurality of downlink reference signals included in the group of downlink reference signals using resources having the same time and frequency. The base station according to claim 6 or 7 , wherein the control unit transmits each of the plurality of groups of downlink reference signals using resources that are orthogonal to each other at least in time or frequency. The control unit emits a beam for transmitting user data to the terminal device based on the information indicating the reception result of the plurality of groups of downlink reference signals in the terminal device, and the plurality of groups of downlink references. selecting from each of the plurality of first group of eNB beam used for transmitting the signal, the base station according to any one of claims 6-8. The base station according to claim 9 , wherein the control unit transmits the same user data to the terminal device using a plurality of selected beams. Forming multiple UE beams in each of multiple directions to communicate with the base station,
Transmission by the processor using UE beams with each of the multiple uplink reference signals directed in different directions,
Including
Each of the plurality of groups of downlink reference signals transmitted using the plurality of groups of eNB beams selected by the base station according to the reception result of the plurality of uplink reference signals is received, and the plurality of downlink reference signals are received. Information indicating the reception result of a group of downlink reference signals is reported to the base station, and a plurality of groups of eNB beams selected by the base station according to the reception result of the plurality of groups of downlink reference signals. A method of receiving data transmitted using each. Computer,
A communication unit that forms multiple UE beams in each of multiple directions and communicates with the base station.
A control unit that transmits each of a plurality of uplink reference signals using a UE beam directed in different directions,
To function as
The communication unit receives each of the plurality of groups of downlink reference signals transmitted using the plurality of groups of eNB beams selected by the base station according to the reception result of the plurality of uplink reference signals. And
The control unit reports to the base station information indicating the reception result of the plurality of groups of downlink reference signals.
The communication unit provides a program for receiving data transmitted using each of the plurality of groups of eNB beams selected by the base station according to the reception result of the plurality of groups of downlink reference signals. The recording medium on which it was recorded. To form a group of eNB beam passing through each of the plurality of paths arriving from different directions for the terminal device in communication with the terminal device, and transmits using a plurality of UE beams said terminal device is directed to a plurality of directions To receive multiple uplink reference signals
Each of the plurality of groups of downlink reference signals selected according to the reception result of the plurality of uplink reference signals is used as a group of eNB beams passing through each of the plurality of paths arriving from different directions for the terminal device. To send and
Including
Information indicating the reception result of the plurality of groups of downlink reference signals is received from the terminal device, and the plurality of groups of eNB beams are selected according to the reception results of the plurality of uplink reference signals, and the selected plurality of eNB beams are selected. A method of transmitting data to the terminal device using each of a group of eNB beams. Computer,
To form a group of eNB beam passing through each of the plurality of paths arriving from different directions for the terminal device in communication with the terminal device, and transmits using a plurality of UE beams said terminal device is directed to a plurality of directions A communication unit that receives multiple uplink reference signals,
Each of the plurality of groups of downlink reference signals selected according to the reception result of the plurality of uplink reference signals is used as a group of eNB beams passing through each of the plurality of paths arriving from different directions for the terminal device. And the control unit to send
To function as
The communication unit receives information indicating the reception result of the plurality of groups of downlink reference signals from the terminal device.
The control unit selects a plurality of groups of eNB beams according to the reception results of the plurality of uplink reference signals.
The communication unit is a recording medium on which a program for transmitting data to the terminal device using each of a plurality of selected groups of eNB beams is recorded.

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