Apparatus and method

Abstract

An object of the present invention is to provide a mechanism for more effectively selecting a beam suitable for downlink transmission. An apparatus comprising: an acquisition unit that acquires setting information from a base station; and a selection support unit that transmits an uplink reference signal for the base station to use for selecting a beam to use in downlink transmission using at least one first unit frequency band indicated by the setting information and from a group including a plurality of unit frequency bands.

Description

[0001] This application is a divisional application of the invention patent application with application number 201680057261.4, application date July 8, 2016, and invention title "Apparatus and Method". Technical Field

[0002] This invention relates to an apparatus and a method. Background Technology

[0003] The wireless communication environment has faced the challenge of rapidly increasing data traffic in recent years. Therefore, 3GPP is researching ways to increase network density and distribute traffic by incorporating numerous small cells within macrocells. This technique utilizing small cells is known as small cell enhancement. It's important to note that small cells conceptually can include various cell types smaller than macrocells and arranged to overlap with them (e.g., femtocells, nanocells, picocells, microcells, etc.).

[0004] In addition, as a way to expand wireless resources, the utilization of a 6 GHz or higher frequency band known as the millimeter wave band is being studied. However, due to the strong linearity and significant radio propagation attenuation of the millimeter wave band, its use is expected in small cells smaller than macrocells. Because the millimeter wave band is so extensive, the techniques required to effectively select appropriate communication frequencies from this broad band become important. One such technique involves using a reference signal to measure the state of the channel (specifically, the characteristics or quality of the channel). For example, a base station can select an appropriate channel for communicating with a terminal device by measuring an uplink reference signal transmitted from the terminal device. As another technique concerning the uplink, for example, Patent Document 1 mentioned below discloses a technique for setting the appropriate transmission power for the uplink signal.

[0005] Citation List

[0006] Patent documents

[0007] Patent Document 1: JP 2013-93910A Summary of the Invention

[0008] Technical issues

[0009] Suppose beamforming is performed during downlink transmission, where millimeter-wave bands are used to compensate for radio wave propagation attenuation. Since the appropriate beam can vary depending on the location of the base station and terminal equipment, it is desirable to select the appropriate beam based on measurements of a reference signal. However, the process of measuring the reference signal can be complicated by the wide range of millimeter-wave bands. Therefore, a mechanism is desired to provide that can more effectively select a beam suitable for downlink transmission.

[0010] Solution

[0011] According to this disclosure, an apparatus is provided, comprising: an acquisition unit configured to acquire setting information from a base station; and a selection support unit configured to transmit an uplink reference signal using at least one first unit band comprising a group of a plurality of unit bands indicated by the setting information, the uplink reference signal being used to select a beam used by the base station in downlink transmission.

[0012] Additionally, according to this disclosure, an apparatus is provided, comprising: a setting unit configured to send setting information to a terminal device indicating at least one first unit frequency band comprising a group of multiple unit frequency bands; and a selection unit configured to select a beam used in downlink transmission based on measurement results of an uplink reference signal transmitted by the terminal device using the first unit frequency band.

[0013] Additionally, according to this disclosure, a method is provided, comprising: obtaining configuration information from a base station; and using at least one first unit frequency band comprising a group of multiple unit frequency bands indicated by the configuration information, transmitting via a processor an uplink reference signal for selecting a beam used by the base station in downlink transmission.

[0014] Additionally, according to this disclosure, a method is provided, comprising: sending setting information indicating at least one first unit frequency band comprising a group of multiple unit frequency bands to a terminal device; and, based on measurement results of an uplink reference signal transmitted by the terminal device using the first unit frequency band, selecting by a processor a beam used in downlink transmission.

[0015] Beneficial effects

[0016] According to the above disclosure, a mechanism is provided that can more effectively select a beam suitable for downlink transmission. It should be noted that the above effects are not necessarily limiting. Any of the effects shown in this specification or other effects that can be understood from this specification can be achieved by using or replacing the above effects. Attached Figure Description

[0017] Figure 1 This is an explanatory diagram illustrating an overview of a system according to an embodiment of the present disclosure.

[0018] Figure 2 This is an explanatory diagram used to illustrate component carriers.

[0019] Figure 3 This is a block diagram illustrating an example configuration of a base station according to this embodiment.

[0020] Figure 4 This is a block diagram illustrating an example configuration of a terminal device according to this embodiment.

[0021] Figure 5 This is an explanatory diagram used to illustrate the technical features of the first embodiment.

[0022] Figure 6 This is a timing diagram illustrating an example of the communication processing flow performed in the system of this first embodiment.

[0023] Figure 7 This is an explanatory diagram used to illustrate the technical features of the second embodiment.

[0024] Figure 8 This is a timing diagram illustrating an example of the communication processing flow performed in the system of this second embodiment.

[0025] Figure 9 This is an explanatory diagram used to illustrate the technical features of the third embodiment.

[0026] Figure 10 This is an explanatory diagram used to illustrate the technical features of the third embodiment.

[0027] Figure 11 This is an explanatory diagram used to illustrate the technical features of the third embodiment.

[0028] Figure 12 This is an explanatory diagram used to illustrate the technical features of the third embodiment.

[0029] Figure 13 This is an explanatory diagram used to illustrate the technical features of the third embodiment.

[0030] Figure 14 This is an explanatory diagram used to illustrate the technical features of the fourth embodiment.

[0031] Figure 15 This is an explanatory diagram used to illustrate the technical features of the fourth embodiment.

[0032] Figure 16 This is an explanatory diagram used to illustrate the technical features of the fourth embodiment.

[0033] Figure 17 This is a block diagram illustrating a first example of a schematic configuration of an eNB.

[0034] Figure 18 This is a block diagram illustrating a second example of a schematic configuration of an eNB.

[0035] Figure 19 This is a block diagram illustrating an example of a schematic configuration of a smartphone.

[0036] Figure 20 This is a block diagram illustrating an example of a schematic configuration of a car navigation system. Detailed Implementation

[0037] In the following, preferred embodiments of the present disclosure (a) will be described in detail with reference to the accompanying drawings. Note that in this specification and the drawings, structural elements having substantially the same function and structure are indicated by the same reference numerals, and repeated descriptions of these structural elements are omitted.

[0038] Please note that the explanation will be given in the following order.

[0039] 1. Introduction

[0040] 1.1. Small Cellular Cells

[0041] 1.2. Carrier Aggregation

[0042] 1.3. Review of millimeter-wave frequency bands

[0043] 1.4. Beamforming

[0044] 2. Configuration Example

[0045] 2.1. Example of base station configuration

[0046] 2.2. Configuration Example of Terminal Device

[0047] 3. First Embodiment

[0048] 3.1. Technical Issues

[0049] 3.2. Technical Features

[0050] 3.3. Processing Flow

[0051] 4. Second Embodiment

[0052] 4.1. Technical Issues

[0053] 4.2. Technical Features

[0054] 4.3. Processing Flow

[0055] 5. Third embodiment

[0056] 5.1. Technical Issues

[0057] 5.2. Technical Features

[0058] 6. Fourth Embodiment

[0059] 6.1. Technical Issues

[0060] 6.2. Technical Features

[0061] 7. Application Examples

[0062] 8. Summary

[0063] <<1. Introduction>>

[0064] <1.1. Small Cellular Cells>

[0065] Figure 1 This is an explanatory diagram illustrating an overview of system 1 according to an embodiment of the present disclosure. (See diagram for example.) Figure 1 As shown, system 1 includes base station 10, terminal equipment 20 and communication control device 30.

[0066] exist Figure 1 In this example, the communication control device 30 is a macrocell base station. The macrocell base station 30 provides wireless communication services to one or more terminal devices 20 located within macrocell 31. Macrocell base station 30 is connected to core network 15. Core network 15 is connected to packet data network (PDN) 16 via a gateway device (not shown). For example, macrocell 31 can operate according to any wireless communication method, such as LTE, LTE-A, GSM (registered trademark), UMTS, W-CDMA, CDMA200, WiMAX, WiMAX2, or IEEE 802.16. Note that this is not limited to... Figure 1 For example, the control node (master node of the macrocell base station) in core network 15 or PDN 16 can have the function of cooperatively controlling wireless communication in macrocells and small cells. Note that a macrocell base station can also be referred to as a macro eNodeB.

[0067] Base station 10 is a small cell base station utilizing small cells 11. Typically, small cell base station 10 is authorized to allocate radio resources to terminal devices 20 connected to its own devices. However, the allocation of radio resources can be delegated at least partially to communication control device 30 for cooperative control. Base station 10 can be as follows: Figure 1 The small cell base station shown can be a fixed installation or a dynamic access point (AP) utilizing the small cell 11. Note that the small cell base station can also be referred to as a pico eNB or femto eNB.

[0068] Terminal device 20 connects to macrocell base station 30 or small cell base station 10 to enjoy wireless communication services. For example, terminal device 20 connected to small cell base station 10 receives control signals from macrocell base station 30 and data signals from small cell base station 10. Terminal device 20 is also referred to as a user. A user can also be referred to as user equipment (UE). Here, UE can be a UE as defined in LTE or LTE-A, or more generally, it can refer to communication equipment.

[0069] <1.2. Carrier Aggregation>

[0070] The following describes the technologies related to carrier aggregation as specified in LTE Release 10 (i.e., 3GPP Release 10).

[0071] (1) Component carrier

[0072] Carrier aggregation is a technique that improves communication throughput by aggregating multiple unit frequency bands supported in LTE to form a communication channel between a base station and a terminal device. A single unit frequency band included in a communication channel formed by carrier aggregation is called a component carrier (CC). Here, CC can be the CC defined in LTE or LTE-A, or more generally, it can represent a unit frequency band.

[0073] In LTE version 10, up to five frequency control areas (CCs) can be aggregated. Additionally, each CC has a 20MHz bandwidth. Note that the CCs to be aggregated can be configured consecutively on the frequency axis or separately. Furthermore, the CCs to be aggregated and used can be configured for each terminal device.

[0074] The aggregated multiple communication carriers (CCs) are divided into a primary component carrier (PCC) and secondary component carriers (SCCs) excluding the PCC. Each terminal device has a different PCC. Since the PCC is the most important CC, it is desirable to select the CC with the most stable communication quality.

[0075] Figure 2 This is an explanatory diagram used to illustrate component carrier waves. In Figure 2 The example illustrates a scenario where two UEs aggregate using some of the five CCs. Specifically, UE1 aggregates using CC1, CC2, and CC3, while UE2 aggregates using CC2 and CC4. Furthermore, UE1's PCC is CC2, and UE2's PCC is CC4.

[0076] Here, the choice of PCC depends on the implementation. An SCC is changed by deleting it and adding another. In other words, directly changing an SCC is difficult.

[0077] (2) Formation and changes of PCC

[0078] When a terminal device transitions from an RRC idle state to an RRC connected state, the first CC to establish a connection is the PCC. The PCC is then changed through a process similar to a handover.

[0079] PCC is established through a process called connection establishment. This process is initiated by a request from the terminal device.

[0080] PCC is changed through a process called connection reconfiguration. This process includes sending and receiving handover messages. This process begins from the base station side.

[0081] (3) Increase in SCC

[0082] The SCC is added through a process called connection reconfiguration. This process begins at the base station. The SCC is added to the PCC and becomes part of the PCC. Adding an SCC is also known as activating the SCC.

[0083] (4) Deletion of SCC

[0084] SCCs are deleted through a process called connection reconfiguration. This process begins on the base station side. During this process, the specific SCC specified in the message is deleted. Note that SCC deletion is also performed through a process called connection reconstruction. This process begins on the terminal device side. Through this process, all SCCs are deleted. Deleting an SCC is also known as deactivating an SCC.

[0085] (5) Special role of PCC

[0086] The PCC has a unique function distinct from the SCC. For example, NAS signaling during connection establishment is transmitted and received only in the PCC. Additionally, the Physical Uplink Control Channel (PUCCH) is transmitted only in the PCC. Note that examples of uplink control signals include ACK or NACK indicating successful or failed reception of data transmitted in the downlink, scheduling requests, etc. Furthermore, the process from detecting a radio link failure to connection reconstruction also occurs only in the PCC.

[0087] (6) LTE version 12

[0088] LTE version 12 illustrates the use of different frequencies for macrocell and small cell base stations. For example, frequencies of approximately 2 GHz can be allocated to macrocell base stations, while higher frequencies such as 5 GHz can be allocated to small cell base stations.

[0089] <1.3. Review of Millimeter Wave Frequency Band>

[0090] The following will explain the review process for the millimeter-wave band.

[0091] (1) Definition

[0092] Generally, radio waves with frequencies from 3 GHz to 30 GHz (i.e., wavelengths from 1 cm to 10 cm) are also referred to as centimeter waves. Additionally, radio waves with frequencies from 30 GHz to 300 GHz (i.e., wavelengths from 1 cm to 1 mm) are also referred to as millimeter waves. Furthermore, radio waves with frequencies from 10 GHz to 30 GHz are also referred to as quasi-millimeter waves. In this specification, the millimeter wave band refers to the band of 6 GHz or higher of the aforementioned frequencies. In other words, the concept of millimeter waves in this specification also includes general centimeter waves.

[0093] (2) Relationship with component carrier

[0094] Millimeter wave bands have extensive frequency resources. Therefore, LTE version 10 assumes that the bandwidth of the 20MHz frequency CC can be changed to a wider bandwidth in the millimeter wave band, such as 40MHz, 80MHz, or 160MHz.

[0095] (3) Line-of-sight communication

[0096] The higher the frequency of radio waves, the less diffraction they undergo and the stronger their linearity. Furthermore, the higher the frequency of radio waves, the more they attenuate upon reflection. Therefore, it can be said that millimeter-wave radio waves (especially those with frequencies of 10 GHz or higher) are essentially assumed to be used for line-of-sight communication.

[0097] (4) Radio wave propagation loss per frequency band

[0098] Typically, radio wave propagation loss (i.e., path loss) is significant, as radio waves attenuate with respect to the square of the frequency. For example, frequencies in the 20 GHz band attenuate by more than 12 dB compared to frequencies in the 5 GHz band. Frequencies in the 60 GHz band attenuate by more than 22 dB compared to frequencies in the 5 GHz band.

[0099] Millimeter-wave bands span a wide frequency range, from 6 GHz to 60 GHz. This is significantly wider than the 2 GHz band currently used by LTE. Furthermore, due to this wide band width, radio waves within millimeter-wave bands are not uniform, and there are instances where radio waves belonging to the same millimeter-wave band exhibit significantly different characteristics.

[0100] It is known that radio waves at frequencies of 6 GHz or higher have difficulty reaching their destination. Therefore, when millimeter-wave radio waves are used to establish a link between the UE and eNB, it is difficult to guarantee that the link can be maintained stably. To address this, the use of lower-frequency radio waves to control higher-frequency radio waves has been proposed. In fact, the technique of using 2 GHz band CC to control 5 GHz band CC has been discussed in the review of small cells in LTE Release 12.

[0101] Millimeter-wave bands have resources spanning a wide range from approximately 6 GHz to 60 GHz. Therefore, even if an attempt is made to use a 2 GHz band CC to control a wide range of resources, the resources available for a 2 GHz band CC may be insufficient.

[0102] (5) Change in subcarrier spacing

[0103] In LTE and 3GPP Release 12, the subcarrier spacing of Orthogonal Frequency Division Multiplexing (OFDM) is 15 kHz. This 15 kHz bandwidth is defined as experiencing gradual attenuation on a subcarrier basis. Therefore, even when frequency-selective attenuation occurs across the entire bandwidth (e.g., a 20 MHz bandwidth), the gradual attenuation ultimately occurs on a subcarrier basis. As mentioned above, the advantage of the 15 kHz bandwidth is that its frequency characteristics deteriorate very little at the receiving frequency.

[0104] It is predicted that the frequency bandwidth where gradual attenuation occurs will increase in the 10 GHz to 60 GHz band. For example, it is thought that the subcarrier spacing of 15 kHz in the 2 GHz band can be changed to 150 kHz in the 20 GHz band.

[0105] However, because such changes in subcarrier spacing have a significant impact on LTE specifications, it is difficult to assume that the subcarrier spacing can be changed steplessly. Therefore, it is desirable to change the subcarrier spacing in approximately four levels, such as 15kHz, 30kHz, 60kHz, and 120kHz. This is because even if the subcarrier spacing is divided into more levels, the effect of more levels will not be significant when the specification change is too large. The following shows an example of a setup where the subcarrier spacing can be changed in four levels.

[0106] [Table 1]

[0107]

[0108] However, even with OFDM subcarrier spacing varying by approximately four levels, the problem of increased CC load in low-frequency bands (e.g., the 2 GHz band) remains unresolved. This is because millimeter-wave bands have extensive frequency resources and require a large number of control signals. Referring to Table 1 above, it can be determined that the number of CCs to be controlled within the millimeter-wave band is substantial.

[0109] Note that questions remain regarding whether OFDM is being used in the 60 GHz or higher frequency bands. However, even if the schedule for processing signals changes depending on the frequency band used, there is no doubt that there are abundant frequency resources and numerous control objectives.

[0110] (6) UE capabilities

[0111] Because millimeter-wave bands have a wide frequency range, the number of control cells (CCs) is correspondingly large. With hundreds of CCs, it's conceivable that some UEs could use, for example, approximately 100 CCs in total, while others could only use a maximum of a few CCs. It should be noted that these UEs can have different capabilities within the millimeter-wave bands described above.

[0112] (7) CCs with the same characteristics

[0113] CCs with a bandwidth of 20MHz are used in the 2GHz and 5GHz bands, and in the prior art, the channel characteristics of these CCs can differ. On the other hand, in the millimeter-wave band, as the frequency increases, the channel characteristics tend to flatten out, and the channel characteristics of CCs tend to become similar. For example, in the 30GHz band, the channel characteristics are flattened over approximately 200MHz. When assuming the existence of terminal devices capable only of processing CCs with a bandwidth of 20MHz, it is desirable to manage resources by dividing the 200MHz bandwidth into CCs with bandwidths of 20MHz. In this case, the channel characteristics of CCs with frequencies close to 20MHz can be substantially the same.

[0114] <1.4. Beamforming>

[0115] Assume beamforming is performed in the millimeter-wave band to compensate for the attenuation of radio wave propagation. This is because the antenna gain obtained through beamforming can compensate for the attenuation of radio wave propagation. This antenna gain is achieved by focusing the beam in a specific direction rather than radiating radio waves in all directions. This is because energy scattered in all directions is concentrated in one direction.

[0116] Antenna gain increases with the sharpness of the beam. Therefore, it is effective to use many antenna elements to maximize gain. When using millimeter-wave bands, it is best to configure hundreds of antennas. For this purpose, it is assumed that beamforming is used on the base station side rather than on the terminal device side. This is because, considering space and computing power, it is inappropriate to install hundreds of antennas on the terminal device.

[0117] When beamforming is assumed to be performed by the base station, it is desirable to select a beam suitable for each terminal device. This selection can be made by either the terminal device or the base station. However, the final selection is considered to be made by the base station. When selecting the beam for downlink transmission from the base station to the terminal device, it is desirable to be able to directly or indirectly measure the state of the downlink channel.

[0118] Downlink reference signals can be used to measure downlink channels. However, due to significant attenuation of radio waves in the millimeter-wave band, it is difficult to accurately measure the channel state using omnidirectional downlink reference signals. Therefore, beamforming of the downlink reference signal is desirable. However, since the downlink state is unknown at the time of transmission of the downlink reference signal, it is difficult to perform beamforming only in the appropriate directions. Therefore, a technique is considered in which the beamformed downlink reference signal is transmitted in all directions, and the terminal device sequentially measures the channel while changing the measurement time. However, according to this technique, the terminal device requires a large amount of processing time and high power consumption.

[0119] Therefore, techniques for measuring the state of the uplink channel using an uplink reference signal and for measuring the state of the downlink channel based on the uplink channel state are important. For example, in time-division duplex (TDD) systems using the same channel in both the uplink and downlink, the channel characteristics are identical in both, making the aforementioned techniques particularly effective. When applying this technique to beamforming of the downlink reference signal, the base station selects a suitable beam for transmitting the downlink reference signal based on measurements of the uplink reference signal transmitted from the terminal equipment. In this case, the downlink reference signal is transmitted only in a specific direction, and the terminal equipment does not transmit the uplink reference signal in multiple directions, thus allowing for the selection of a beam for downlink transmission within a short timeframe.

[0120] However, the following problems arise when the above technology is assumed to be used in the millimeter-wave band.

[0121] The first issue is the vast millimeter-wave band. The uplink reference signal transmitted by the terminal device is sent on each control center (CC), and is therefore assumed to be used for measurement of each CC. This is because CCs can have different characteristics. Regarding this issue, since there can be hundreds of CCs in the millimeter-wave band, a mechanism is needed that can effectively measure each CC.

[0122] The second problem is that the antenna gain is very low regardless of whether the uplink reference signal is omnidirectional or directional. This is because, due to limited installation space, the number of antennas that can be installed in the terminal equipment is assumed to be about 8. Since radio wave propagation is significantly attenuated in the millimeter-wave band, the base station may be unable to receive the uplink reference signal if the signal is omnidirectional or the antenna gain is low.

[0123] <<2. Configuration Example>>

[0124] <2.1. Example of base station configuration>

[0125] Below, we will refer to Figure 3 The configuration of base station 10 according to an embodiment of the present disclosure is described. Figure 3 This is a block diagram illustrating an example configuration of a base station 10 according to an embodiment of the present disclosure. (See also:) Figure 3 The base station 10 includes an antenna unit 110, a wireless communication unit 120, a network communication unit 130, a storage unit 140, and a processing unit 150.

[0126] (1) Antenna element 110

[0127] Antenna unit 110 radiates the signal output by wireless communication unit 120 into space in the form of radio waves. Antenna unit 110 also converts the radio waves in space into signals and outputs the signals to wireless communication unit 120.

[0128] (2) Wireless communication unit 120

[0129] The wireless communication unit 120 transmits and receives signals. For example, the wireless communication unit 120 transmits downlink signals to the terminal device and receives uplink signals from the terminal device.

[0130] (3) Network communication unit 130

[0131] Network communication unit 130 sends and receives information. For example, network communication unit 130 sends information to other nodes and receives information from other nodes. Other nodes include other base stations and core network nodes.

[0132] (4) Storage unit 140

[0133] Storage unit 140 temporarily or permanently stores programs and various data used for the operation of base station 10.

[0134] (5) Processing unit 150

[0135] The processing unit 150 provides various functions of the base station 10. The processing unit 150 includes a setting unit 151 and a selection unit 153. Note that the processing unit 150 may also include structural elements other than these structural elements. That is, the processing unit 150 can perform operations other than those of these structural elements.

[0136] The operation of setting unit 151 and selecting unit 153 will be explained in detail later.

[0137] <2.2. Configuration Example of Terminal Device>

[0138] Below, we will refer to Figure 3 An example illustrating the configuration of a terminal device 20 according to an embodiment of the present disclosure. Figure 4 This is a block diagram illustrating an example configuration of a terminal device 20 according to an embodiment of the present disclosure. (See also:) Figure 4 The terminal device 20 includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a processing unit 240.

[0139] (1) Antenna element 210

[0140] Antenna unit 210 radiates the signal output by wireless communication unit 220 into space in the form of radio waves. Antenna unit 210 also converts the radio waves in space into signals and outputs the signals to wireless communication unit 220.

[0141] (2) Wireless communication unit 220

[0142] The wireless communication unit 220 transmits and receives signals. For example, the wireless communication unit 220 receives downlink signals from the base station and transmits uplink signals to the base station.

[0143] (3) Storage unit 230

[0144] Storage unit 230 temporarily or permanently stores programs and various data used for the operation of terminal device 20.

[0145] (4) Processing unit 240

[0146] The processing unit 240 provides various functions of the terminal device 20. The processing unit 240 includes an acquisition unit 241 and a selection support unit 243. Note that the processing unit 240 may also include structural elements other than these structural elements. That is, the processing unit 240 can perform operations other than those of these structural elements.

[0147] The operations of acquiring unit 241 and selecting support unit 243 will be explained in detail later.

[0148] <<3. First Embodiment>>

[0149] <3.1. Technical Issues>

[0150] The technical problem of this embodiment is the first problem mentioned above. More specifically, since there are a large number of carrier aggregation (CCs) in the millimeter-wave band, in order to increase the data transmission speed, it is assumed that multiple CCs are combined and used simultaneously (i.e., carrier aggregation is performed). Since using each of the multiple CCs to be used simultaneously requires selecting an appropriate beam, the measurement of the channel characteristics of each CC can be a significant burden on the terminal device in terms of power consumption.

[0151] Therefore, this embodiment provides a mechanism for effectively measuring each CC.

[0152] <3.2. Technical Features>

[0153] (1) Grouping of CC

[0154] In this embodiment, a group consisting of some of a plurality of CCs is defined for use with base station 10. This group includes at least one (typically multiple) CCs. This group is also referred to below as an uplink RS group. An uplink RS group includes at least one uplink RS primary CC. Figure 5 An example of an uplink RS group is shown.

[0155] Figure 5An example of an uplink RS group comprising four CCs is shown. The first uplink RS group includes CC1 to CC4, with CC2 being the main uplink RS CC. The second uplink RS group includes CC5 to CC8, with CC5 being the main uplink RS CC. The number of CCs included in an uplink RS group is arbitrary. Furthermore, the position of the main uplink RS CCs within each uplink RS group is also arbitrary. Note that the main uplink RS CCs correspond to the first unit frequency band. CCs included in the uplink RS groups other than the main uplink RS CCs correspond to the second unit frequency band.

[0156] (2) Beam selection

[0157] Terminal device 20 (e.g., selection support unit 243) transmits an uplink reference signal using at least one main uplink RS of an uplink RS group comprising multiple CCs indicated by setting information (described below). This uplink reference signal is used to select the beam used by base station 10 in downlink transmission. Note that the uplink reference signal will also be referred to below as the uplink RS. The uplink RS can also be referred to as a sounding reference signal (RSR) in existing LTE technologies. The uplink RS is transmitted only on the main uplink RS of the uplink RS group. Therefore, compared to transmitting the uplink RS on all of a large number of CCs in the millimeter-wave band, the power consumption of terminal device 20 can be reduced.

[0158] Base station 10 (e.g., selection unit 153) selects the beam used in downlink transmission based on the measurement results of the uplink RS transmitted by terminal device 20 using the uplink RS main CC. For example, base station 10 (e.g., selection unit 153) measures the receive beam that increases the signal-to-noise ratio (SNR) of the uplink RS, while virtually changing the receive beam relative to the uplink RS, and selects a transmit beam suitable for terminal device 20 based on the measurement results.

[0159] Subsequently, base station 10 (e.g., selection unit 153) transmits a downlink reference signal using the selected beam. Note that the downlink reference signal is also referred to below as the downlink RS. Because the beam compensates for radio wave attenuation in the millimeter-wave band, terminal device 20 can successfully receive the downlink RS, thereby accurately measuring the channel state. Base station 10 can transmit the downlink RS using all of the multiple CCs included in the uplink RS group. At this time, terminal device 20 can measure each CC included in the uplink RS group.

[0160] Base station 10 (e.g., selection unit 153) can select one or more beams based on the uplink RS. That is, base station 10 can reduce beam candidates to one or more based on the uplink RS. In this case, base station 10 uses the reduced one or more beam candidates to transmit one or more downlink RSs. Terminal device 20 (e.g., selection support unit 243) uses the one or more beams selected based on the uplink RS to transmit (i.e., provide feedback) information about the measurements of the downlink RS transmitted by base station 10 to base station 10. Terminal device 20 can simply feed back information indicating the measurement results of the downlink RS, or select a beam suitable for downlink transmission based on the measurement results and feed back that selection result. In the latter case, terminal device 20 further reduces the one or more beam candidates that have been reduced by base station 10. Note that the feedback can be sent using the uplink RS main CC. Then, base station 10 determines the beam to be used for downlink data transmission from the candidates based on the feedback. Using the above process, base station 10 can select a beam based on the measurement results of each CC included in the uplink RS group, thereby achieving a more appropriate beam selection.

[0161] (3) Settings

[0162] Base station 10 and terminal equipment 20 are configured with uplink RS groups and uplink RS main CCs for each uplink RS group.

[0163] To perform this configuration, base station 10 and terminal device 20 acquire information indicating the multiple CCs contained in each uplink RS group (i.e., information indicating which CC belongs to which uplink RS group). This information is also referred to below as group information. Additionally, base station 10 and terminal device 20 acquire information indicating the uplink RS master CC of each uplink RS group (i.e., information indicating which CC is the uplink RS master CC). This information is also referred to below as master information. Base station 10 and terminal device 20 can configure the uplink RS groups and the uplink RS master CCs of each uplink RS group by acquiring the group information and master information. Note that group information and master information correspond to configuration information.

[0164] Base station 10 obtains configuration information from, for example, a Mobility Management Entity (MME). Alternatively, base station 10 may obtain information through an Operation and Maintenance (O&M) interface, etc. Additionally, terminal device 20 (e.g., acquisition unit 241) obtains configuration information from base station 10. Conversely, base station 10 (e.g., configuration unit 151) may also be referred to as notifying terminal device 20 of configuration information. For example, dedicated signaling may be used in this notification. This configuration information may be common to all base stations 10 included in system 1, or it may differ from each base station 10. For example, group information may be common, but primary information may differ from each base station 10 (i.e., cellular). In this case, each base station 10 (e.g., configuration unit 151) may obtain group information from the MME, independently select the uplink RS primary CC, and notify the terminal device 20 under its control of the group information and primary information.

[0165] <3.3. Processing Flow>

[0166] Figure 6 This is a timing diagram illustrating an example of the communication processing flow performed in system 1 according to this embodiment. Base station 10 and terminal device 20 are included in this order.

[0167] like Figure 6 As shown, firstly, base station 10 obtains group information (step S102). Then, base station 10 determines the main CC of the uplink RS for each uplink RS group indicated by the obtained group information (step S104). Next, base station 10 sends the group information and main information to terminal device 20 (step S106).

[0168] Next, based on the received group information and main information, terminal device 20 transmits uplink RS using the main CC of uplink RS (step S108). Then, base station 10 selects multiple beam candidates based on the measurement results of the uplink RS (step S110). Then, base station 10 transmits multiple downlink RSs that have undergone beamforming using the selected multiple beam candidates (step S112).

[0169] Next, based on the measurement results of the downlink RS after beamforming, terminal device 20 selects a beam candidate suitable for its downlink transmission (step S114) and feeds back information indicating the selection result to base station 10 (step S116). Note that base station 10 can use the beam selected in step S110 that is evaluated as the most suitable for communication with terminal device 20 to receive this feedback. Then, base station 10 uses the beam indicated by the feedback from terminal device 20 to send user data to terminal device 20 (step S118).

[0170] The process ends with the steps described above.

[0171] <<4. Second Embodiment>>

[0172] <4.1. Technical Issues>

[0173] In the first embodiment, an uplink RS primary CC is set for each cell (i.e., a cell-specific setting). Therefore, depending on the number of terminal devices 20 connected to the cell, the resources for the uplink RS primary CC for transmitting uplink RS may be insufficient. Furthermore, each terminal device 20 may have different capabilities. For example, each terminal device 20 may have different available frequencies, the number of CCs that can be aggregated and used simultaneously, the bandwidth of the available CCs, etc. Therefore, each terminal device 20 may have a different appropriate uplink RS primary CC.

[0174] Therefore, this embodiment provides a mechanism that enables the setting of the uplink RS primary CC for each terminal device 20.

[0175] <4.2. Technical Features>

[0176] Terminal device 20 (e.g., selection support unit 243) sends capability information indicating the CCs that can be used by terminal device 20 to base station 10. This capability information may include, for example, information indicating available uplink RS groups and available CCs contained in those uplink RS groups. Therefore, base station 10 selects the primary uplink RS CC suitable for terminal device 20.

[0177] Base station 10 (e.g., setting unit 151) variably sets the uplink RS primary CC for each terminal device 20. Specifically, base station 10 selects the uplink RS primary CC based on capability information. Therefore, the selected uplink RS primary CC is suitable for the terminal device 20. The following will refer to... Figure 7 This explains the selection of the primary CC in the uplink RS based on capability information.

[0178] Figure 7An example of an uplink RS group consisting of four CCs, CC1 to CC4, is shown. Assume, for example, 10 terminal devices 20 have the capability to use CC1 to CC3, and another 10 terminal devices 20 have the capability to use CC2 to CC4. Since CC2 and CC3 can be used by a total of 20 terminal devices 20, the proportion of data occupied by the uplink RS becomes high when these CCs are used for uplink RS transmission, which may cause processing costs to become a problem. Therefore, base station 10 sets CC1 as the main uplink RS CC for the 10 terminal devices 20 with the capability to use CC1 to CC3. Additionally, base station 10 sets CC4 as the main uplink RS CC for the 10 terminal devices 20 with the capability to use CC2 to CC4. This configuration avoids insufficient resources for uplink RS CCs used for uplink RS transmission, and the main uplink RS CC can be configured according to the capabilities of the terminal devices 20. Note that the above configuration method is merely an example, and any of various algorithms can be used.

[0179] <4.3. Processing Flow>

[0180] Figure 8 This is a timing diagram illustrating an example of the communication processing flow performed in System 1 according to this embodiment. Base station 10 and terminal device 20 are included in this timing diagram.

[0181] First, base station 10 obtains such as Figure 8 The group information shown is displayed (step S202). Next, the base station 10 sends the acquired group information to the terminal device 20 (step S204).

[0182] In the timing of the Radio Resource Control (RRC) connection state, terminal device 20 sends capability information to base station 10 (step S206). Then, base station 10 determines the main CC of the uplink RS for terminal device 20 based on the capability information (step S208) and sends the main information to terminal device 20 (step S210). Since the processing of steps S212 to S222 below is similar to the processing of steps S108 to S118 above, its detailed description will be omitted here.

[0183] The process ends with the steps described above.

[0184] <<5. Third Embodiment>>

[0185] <5.1. Technical Issues>

[0186] The technical problem of this embodiment is the second problem mentioned above. As will be explained in more detail, due to the significant attenuation of radio wave propagation in the millimeter-wave band, the uplink RS can reach base station 10 with a low SNR. Therefore, it may be difficult to select the beam of base station 10.

[0187] Therefore, this embodiment provides a mechanism that enables the uplink RS to reach the base station 10 with a high SNR.

[0188] <5.2. Technical Features>

[0189] In existing LTE technology, the uplink RS is called the SRS. Furthermore, a subframe consists of 14 OFDM symbols, and the last 14th OFDM symbol transmits the uplink RS. An example of this structure is shown below. Figure 9 As shown. In Figure 9 In the example shown, in the 14th OFDM symbol, the uplink RS is transmitted with the full bandwidth of the main CC of the uplink RS having a bandwidth of 20 MHz.

[0190] Simultaneously, the terminal device 20 (e.g., the selection support unit 243) transmits the uplink RS in a portion of the frequency band of the main CC of the uplink RS. Afterwards, the terminal device 20 (e.g., the selection support unit 243) concentrates the transmission power corresponding to the level of other frequency bands on this portion of the frequency band. Therefore, the uplink RS can reach the base station 10 with a high SNR. Figure 10 An example of this state is shown in [the image]. Figure 10 In the example shown, in the 14th OFDM, the uplink RS is transmitted on four subcarriers of the main CC of the uplink RS, which has a bandwidth of 20 MHz. The transmission power corresponding to the remaining 92 subcarriers is concentrated on these four subcarriers. The shaded areas in the figure represent the areas where uplink RS is transmitted, while the unshaded areas represent areas where no content is transmitted (i.e., areas transmitting NULL). With a subcarrier spacing of 15 kHz, one OFDM symbol can accommodate 24 uplink RSs. Therefore, 24 terminal devices 20 can simultaneously transmit uplink RS using one OFDM symbol.

[0191] Furthermore, terminal device 20 (e.g., selection support unit 243) can transmit uplink RS on one subcarrier of the main CC of uplink RS. Then, terminal device 20 (e.g., selection support unit 243) concentrates the transmission power corresponding to other frequency bands onto one subcarrier. Compared to, for example, transmitting uplink RS on four subcarriers, transmitting uplink RS on one subcarrier can achieve a 6dB gain improvement. Therefore, uplink RS can arrive at base station 10 with a high SNR. An example of this state is as follows... Figure 11As shown. In Figure 11 In the example shown, in the 14th OFDM symbol, the uplink RS is transmitted on one subcarrier of the main CC of the uplink RS with a bandwidth of 20 MHz. The transmission power corresponding to the level of the remaining 95 subcarriers is concentrated on one subcarrier.

[0192] Furthermore, terminal device 20 (e.g., selection support unit 243) can concentrate the transmission power corresponding to the level of other CCs besides the main CC of the uplink RS contained in the uplink RS group onto the main CC of the uplink RS. In this case, the uplink RS can reach base station 10 with a higher SNR. When the uplink RS group includes 10 CCs and has one main CC of the uplink RS, the 10 CCs can be concentrated into one CC, thereby achieving a 10dB gain improvement. An example of this state is as follows: Figure 12 As shown. In Figure 12 In the example shown, the uplink RS group comprises 10 CCs, and in the 14th OFDM symbol, the uplink RS is transmitted on a subcarrier of the main uplink RS CC with a bandwidth of 20 MHz. The transmission power corresponding to the levels of CC2 to CC10 and the transmission power corresponding to the levels of the remaining 95 subcarriers are concentrated on one subcarrier.

[0193] Furthermore, terminal device 20 (e.g., selection support unit 243) can use all 14 OFDM symbols to transmit the uplink RS. In this case, an increase in gain can be achieved by placing 14 received signals on the symbols by base station 10. An example of this state is as follows: Figure 13 As shown. In Figure 13 In the example shown, the uplink RS is transmitted on one subcarrier of each main CC of the uplink RS, which has a bandwidth of 20 MHz, in 14 OFDM symbols. Additionally, the uplink RS group comprises 10 CCs, with the transmission power of the levels corresponding to CC2 through CC10 and the transmission power of the levels corresponding to the remaining 95 subcarriers concentrated on one subcarrier.

[0194] <<6. Fourth Embodiment>>

[0195] <6.1. Technical Issues>

[0196] According to the third embodiment, the uplink RS can reach base station 10 with a high SNR. Here, as shown in Table 1 above, the subcarrier spacing can be widened to approximately 120 kHz in the millimeter-wave band. This is because the burden of signal processing (e.g., Fast Fourier Transform (FFT) etc.) decreases at high frequencies with channel characteristics approaching the flat characteristics of less fading (e.g., the 60 GHz band, etc.). However, the subcarrier spacing at 120 kHz is 8 times wider than the subcarrier spacing at 15 kHz. Therefore, the power density (dBm / Hz) decreases to 1 / 8, which may lead to a deterioration in the reception characteristics of base station 10.

[0197] Therefore, in this embodiment, a mechanism is provided to maintain the reception characteristics of the base station 10 even when the subcarrier spacing is wide.

[0198] <6.2. Technical Features>

[0199] Terminal device 20 (e.g., selection support unit 243) concentrates the transmission power of the remaining frequency band on another portion of the frequency band of a subcarrier. For example, even if the subcarrier spacing is 120 kHz, terminal device 20 transmits uplink RS by concentrating the transmission power in 15 kHz of the subcarrier spacing. Therefore, even with a wider subcarrier spacing, base station 10 is still able to maintain its reception characteristics. This will be referred to below. Figure 14 and 15 Let me explain in detail.

[0200] like Figure 14 As shown, in the 14th OFDM symbol, the uplink RS is transmitted on a subcarrier with a 120kHz bandwidth, corresponding to the main CC of the uplink RS with a 20MHz bandwidth. The transmission power corresponding to the remaining 95 subcarriers is concentrated on this single subcarrier. Furthermore, the uplink RS is transmitted on a subcarrier in a 15kHz band within the 120kHz band, as shown... Figure 15 As shown. The transmission power corresponding to the remaining 105kHz frequency band level is further concentrated in the 15kHz frequency band.

[0201] Figure 16 An example configuration of a signal processing unit (e.g., wireless communication unit 220) transmitting uplink RS using an interval narrower than the aforementioned subcarrier interval is shown. A 2048-point inverse FFT (IFFT) is performed to generate subcarriers with an interval of 15 kHz. Simultaneously, a 256-point IFFT is performed to generate subcarriers with an interval of 120 kHz. Therefore, as... Figure 16As shown, the wireless communication unit 220 includes a module that performs a 2048-point IFFT and a module that performs a 256-point IFFT. The wireless communication unit 220 uses a selector to select a signal output from either module and sends the signal with a cyclic prefix appended. When transmitting uplink RS, the wireless communication unit 220 selects the signal output from the module performing the 2048-point IFFT. Conversely, when transmitting user data, the wireless communication unit 220 selects the signal output from the module performing the 256-point IFFT via the module performing the FFT. Each signal is time-division multiplexed, and signals including uplink RS and user data are not transmitted simultaneously from a single terminal device 20.

[0202] <<7. Application Examples>>

[0203] The technology disclosed herein can be used in a variety of products. Base station 10 can also be implemented, for example, as any type of evolved Node B (eNB) such as a macro eNB and a small eNB. A small eNB can be an eNB that covers a cell smaller than a macro cell, such as a pico eNB, micro eNB, or femtocell eNB. Conversely, base station 10 can be implemented as another type of base station, such as a Node B or a Base Transceiver Station (BTS). Base station 10 may include a master device for controlling wireless communication (also referred to as a base station device) and one or more remote radio heads (RRHs) located at a different location from the master device. Moreover, the various types of terminals described below can be used as base station 10 by temporarily or semi-permanently performing the functions of base station 10. Furthermore, at least some of the structural elements of base station 10 can be implemented in a base station device or a module for a base station device.

[0204] Furthermore, terminal device 20 can be implemented as a mobile terminal such as a smartphone, tablet computer (PC), laptop computer, portable gaming terminal, portable / dongle mobile router, digital camera, or in-vehicle terminal such as a car navigation device. Additionally, terminal device 20 can be implemented as a machine-type communication (MTC) terminal for establishing machine-to-machine (M2M) communication. Furthermore, at least some structural elements of terminal device 20 can be implemented as modules (e.g., integrated circuit modules including a single die) mounted on these terminals.

[0205] <7.1. Application Examples of Base Stations>

[0206] (First application example)

[0207] Figure 17 This is a block diagram illustrating a first example of a schematic configuration that can be applied to an eNB according to the technology disclosed herein. The eNB 800 includes one or more antennas 810 and a base station device 820. Each antenna 810 and base station device 820 can be connected to each other via an RF cable.

[0208] Each antenna 810 includes one or more antenna elements (e.g., multiple antenna elements constituting a MIMO antenna) and is used by the base station device 820 to transmit and receive wireless signals. The eNB 800 may include, for example... Figure 17 The multiple antennas 810 shown may correspond, for example, to multiple frequency bands used by the eNB 800. It should be noted that, although... Figure 17 An example is shown in which the eNB 800 includes multiple antennas 810, but the eNB 800 may also include a single antenna 810.

[0209] The base station device 820 includes a controller 821, a memory 822, a network interface 823, and a wireless communication interface 825.

[0210] The controller 821, for example, may be a CPU or a DSP, operating various functions of the upper layer of the base station device 820. For example, the controller 821 generates data packets from data in signals processed by the wireless communication interface 825 and transmits the generated data packets via the network interface 823. The controller 821 can generate bundled packets by bundling data from multiple baseband processors to transmit the generated bundled packets. Furthermore, the controller 821 may also have logical functions for performing control such as radio resource control, radio bearer control, mobility management, admission control, and scheduling. Moreover, this control can be performed in cooperation with surrounding eNBs or core network nodes. The memory 822 includes RAM and ROM, storing programs executed by the controller 821 and various control data (e.g., terminal lists, transmit power data, and scheduling data).

[0211] Network interface 823 is a communication interface used to connect base station device 820 to core network 824. Controller 821 can communicate with core network node or another eNB via network interface 823. In this case, eNB 800 can connect to core network node or another eNB via a logical interface (e.g., S1 interface or X2 interface). Network interface 823 can be a wired communication interface or a wireless communication interface for wireless backhaul. When network interface 823 is a wireless communication interface, network interface 823 can use a higher frequency band for wireless communication than that used by wireless communication interface 825.

[0212] The wireless communication interface 825 supports cellular communication systems such as LTE or LTE-Advanced, providing wireless connectivity to terminals located within the cell of the eNB 800 via antenna 810. The wireless communication interface 825 typically includes a baseband (BB) processor 826, RF (radio frequency) circuitry 827, etc. The BB processor 826 can perform, for example, encoding / decoding, modulation / demodulation, multiplexing or demultiplexing, and various signal processing operations at each layer (e.g., L1, Media Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP)). The BB processor 826 can replace the controller 821 and has some or all of the logic functions described above. The BB processor 826 can be a module including memory storing a communication control program, a processor executing the program, and related circuitry; the functionality of the BB processor 826 can be changed by upgrading the program. Furthermore, the module can be a card or blade inserted into a slot in the base station device 820, or a chip mounted on the card or blade. Meanwhile, the RF circuit 827 may include a mixer, filter, amplifier, etc., to transmit and receive wireless signals via the antenna 810.

[0213] The wireless communication interface 825 may include multiple such Figure 17 The shown BB processor 826 may correspond, for example, to multiple frequency bands used by the eNB 800. Furthermore, the wireless communication interface 825 may also include multiple RF circuits 827, such as... Figure 17 As shown, these multiple RF circuits 827 can, for example, correspond to multiple antenna elements. Note that, Figure 17 Only one example is shown in which the wireless communication interface 825 includes multiple BB processors 826 and multiple RF circuits 827. The wireless communication interface 825 may also include a single BB processor 826 or a single RF circuit 827.

[0214] exist Figure 17 In the eNB800 shown, refer to Figure 3One or more structural elements contained in the processing unit 150 (setting unit 151 and / or selection unit 153) can be implemented via the wireless communication interface 825. Alternatively, at least some of these structural elements can be implemented by the controller 821. As an example, a module including a portion (e.g., BB processor 826) or all of the wireless communication interface 825 and / or controller 821 can be installed in the eNB 800, and one or more structural elements can be implemented by this module. In this case, the module can store a program for making the processor act as one or more structural elements (i.e., a program for making the processor perform the operation of one or more structural elements), and can execute the program. As another example, a program for making the processor act as one or more structural elements can be installed in the eNB 800, and the wireless communication interface 825 (e.g., BB processor 826) and / or controller 821 can execute the program. As described above, the eNB 800, base station device 820, or module can be provided as a device including one or more structural elements, and can provide a program for making the processor act as one or more structural elements. In addition, a readable recording medium in which the program is recorded can be provided.

[0215] In addition, Figure 17 In the eNB800 shown, reference Figure 3 The wireless communication unit 120 can be implemented by a wireless communication interface 825 (e.g., RF circuit 827). Furthermore, the antenna unit 110 can be implemented by an antenna 810. Additionally, the network communication unit 130 can be implemented by a controller 821 and / or a network interface 823. Furthermore, the storage unit 140 can be implemented by a memory module 822.

[0216] (Second application example)

[0217] Figure 18 This is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology according to this disclosure can be applied. The eNB 830 includes one or more antennas 840, a base station device 850, and an RRH 860. Each of the antennas 840 and RRH 860 can be connected to each other via an RF cable. Furthermore, the base station device 850 and RRH 860 can be connected to each other via a high-speed line such as an optical fiber.

[0218] Each antenna 840 includes one or more antenna elements (e.g., antenna elements constituting a MIMO antenna) and is used by the RRH 860 to transmit and receive wireless signals. The eNB 830 may include, for example, Figure 18 The multiple antennas 840 shown may correspond, for example, to multiple frequency bands used by the eNB 830. Note that... Figure 18Although an example is shown in which the eNB 830 includes multiple antennas 840, the eNB 830 may also include a single antenna 840.

[0219] The base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857. The controller 851, memory 852, and network interface 853 are connected to a reference... Figure 7 The controller 821, memory 822, and network interface 823 are similar.

[0220] The wireless communication interface 855 supports cellular communication systems such as LTE and LTE-Advanced, providing wireless connectivity to terminals located in the segment corresponding to RRH 860 via RRH 860 and antenna 840. The wireless communication interface 855 may typically include a BB processor 856, etc. Except that the BB processor 856 is connected to the RF circuitry 864 of RRH 860 via connection interface 857, the BB processor 856 is similar to the reference... Figure 17 The BB processor 826 is described above. The wireless communication interface 855 may include multiple BB processors 856, such as... Figure 18 As shown, multiple BB processors 856 can, for example, correspond to multiple frequency bands used by the eNB 830. Note that, although Figure 18 An example is shown in which the wireless communication interface 855 includes multiple BB processors 856, but the wireless communication interface 855 may also include a single BB processor 856.

[0221] Connection interface 857 is an interface for connecting base station device 850 (wireless communication interface 855) to RRH860. This connection interface 857 can be a communication module for communication over a high-speed line connecting base station device 850 (wireless communication interface 855) to RRH860.

[0222] In addition, the RRH 860 includes a connectivity interface 861 and a wireless communication interface 863.

[0223] Connection interface 861 is an interface for connecting RRH860 (wireless communication interface 863) to base station device 850. Connection interface 861 can be a communication module for communication over high-speed lines.

[0224] The wireless communication interface 863 transmits and receives wireless signals via antenna 840. The wireless communication interface 863 typically includes RF circuitry 864, etc. This RF circuitry 864 may include mixers, filters, amplifiers, etc., and transmits and receives wireless signals via antenna 840. Figure 18The multiple RF circuits 864 shown may, for example, correspond to multiple antenna elements. Note that... Figure 18 Although an example is shown in which the wireless communication interface 863 includes multiple RF circuits 864, the wireless communication interface 863 may also include a single RF circuit 864.

[0225] exist Figure 18 In the eNB 830 shown, reference Figure 3 One or more structural elements included in the processing unit 150 (setting unit 151 and / or selection unit 153) can be implemented via wireless communication interface 855 and / or wireless communication interface 863. Alternatively, at least some of these structural elements can be implemented by controller 851. As an example, a module including a portion (e.g., BB processor 856) or all of wireless communication interface 855 and / or controller 851 can be installed in eNB 830, and the one or more structural elements can be implemented by the module. In this case, the module can store a program for making the processor act as one or more structural elements (i.e., a program for making the processor perform the operation of one or more structural elements), and can execute the program. As another example, a program for making the processor act as one or more structural elements can be installed in eNB 830, and wireless communication interface 855 (e.g., BB processor 856) and / or controller 851 can execute the program. As described above, eNB 830, base station device 850, or module can be provided as a device including one or more structural elements, and can provide a program for making the processor act as one or more structural elements. In addition, a readable recording medium in which the program is recorded can be provided.

[0226] In addition, Figure 18 In the eNB 830 shown, for example, refer to Figure 3 The wireless communication unit 120 can be implemented by a wireless communication interface 863 (e.g., RF circuit 864). Furthermore, the antenna unit 110 can be implemented by an antenna 840. Additionally, the network communication unit 130 can be implemented by a controller 851 and / or a network interface 853. Moreover, the storage unit 140 can be implemented by a memory module 852.

[0227] <7.2. Application Examples of Terminal Devices>

[0228] (First application example)

[0229] Figure 19A block diagram illustrating an example of a schematic configuration of a smartphone 900 to which the technology according to this disclosure may be applied is shown. The smartphone 900 includes a processor 901, a memory 902, a storage device 903, an external interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 912, one or more antenna switches 915, one or more antennas 916, a bus 917, a battery 918, and an auxiliary controller 919.

[0230] Processor 901 may be, for example, a CPU or a system-on-a-chip (SoC), which controls the application layer and other functions of smartphone 900. Memory 902 includes RAM and ROM and stores programs and data executed by processor 901. Memory 903 may include storage media such as semiconductor memory and hard disks. External interface 904 is an interface for connecting smartphone 900 to external devices such as memory cards and Universal Serial Bus (USB) devices.

[0231] Camera 906 includes, for example, image sensors such as charge-coupled devices (CCD) and complementary metal-oxide-semiconductor (CMOS) to generate captured images. Sensor 907 may include, for example, a sensor array including a positioning sensor, a gyroscope sensor, a geomagnetic sensor, an accelerometer, etc. Microphone 908 converts sound input to smartphone 900 into audio signals. Input device 909 includes, for example, a touch sensor that detects touch on the screen of display device 910, a keypad, a keyboard, buttons, switches, etc., to accept user input of operations or information. Display device 910 includes a screen such as a liquid crystal display (LCD) and an organic light-emitting diode (OLED) display to display the output images of smartphone 900. Speaker 911 converts the audio signals output from smartphone 900 into sound.

[0232] The wireless communication interface 912 supports cellular communication systems such as LTE or LTE-Advanced and performs wireless communication. The wireless communication interface 912 typically includes a BB processor 913, RF circuitry 914, etc. The BB processor 913 can perform various types of signal processing for wireless communication, such as encoding / decoding, modulation / demodulation, multiplexing / demultiplexing, etc. On the other hand, the RF circuitry 914 can include mixers, filters, amplifiers, etc., and transmits and receives wireless signals via antenna 916. The wireless communication interface 912 can be a single-chip module in which the BB processor 913 and RF circuitry 914 are integrated. The wireless communication interface 912 can include, for example, Figure 19 The diagram shows multiple BB processors 913 and multiple RF circuits 914. Note that... Figure 19Although an example is shown in which the wireless communication interface 912 includes multiple BB processors 913 and multiple RF circuits 914, the wireless communication interface 912 may also include a single BB processor 913 or a single RF circuit 914.

[0233] In addition to cellular communication systems, wireless communication interface 912 can support other types of wireless communication systems, such as short-range wireless communication systems, near-field communication systems, and wireless local area network (LAN) systems. In this case, wireless communication interface 912 may include BB processor 913 and RF circuitry 914 for each wireless communication system.

[0234] Each antenna switch 915 switches the connection target of antenna 916 among multiple circuits (e.g., circuits for different wireless communication systems) contained in wireless communication interface 912.

[0235] Each antenna 916 includes one or more antenna elements (e.g., multiple antenna elements constituting a MIMO antenna) for transmitting and receiving wireless signals from the wireless communication interface 912. The smartphone 900 may include, for example... Figure 19 The multiple antennas 916 are shown. Note that... Figure 19 Although an example is shown in which the smartphone 900 includes multiple antennas 916, the smartphone 900 may also include a single antenna 916.

[0236] Furthermore, the smartphone 900 may include an antenna 916 for various wireless communication systems. In this case, the antenna switch 915 can be omitted from the configuration of the smartphone 900.

[0237] Bus 917 connects processor 901, memory 902, storage 903, external interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 912, and auxiliary controller 919 to each other. Battery 918 is connected via... Figure 19 The power supply line shown in the middle dashed line diagram is directed towards... Figure 19 The various blocks of the smartphone 900 shown are powered. For example, the auxiliary controller 919 operates the minimum necessary functions of the smartphone 900 in sleep mode.

[0238] exist Figure 19 In the smartphone 900 shown, reference Figure 4One or more structural elements included in the processing unit 240 (acquisition unit 241 and / or selection support unit 243) may be implemented by the wireless communication interface 912. Alternatively, at least some of these structural elements may be implemented by the processor 901 or the auxiliary controller 919. As an example, a module including a portion (e.g., BB processor 913) or all of the wireless communication interface 912, processor 901, and / or auxiliary controller 919 may be installed in a smartphone 900, and one or more structural elements may be implemented by this module. In this case, the module may store a program for enabling the processor to function as one or more structural elements (i.e., a program for enabling the processor to perform operations of one or more structural elements), and may execute the program. As another example, a program for enabling the processor to function as one or more structural elements may be installed in the smartphone 900, and the wireless communication interface 912 (e.g., BB processor 913), processor 901, and / or auxiliary controller 919 may execute the program. As described above, the smartphone 900 or the module may be provided as a device including one or more structural elements, and may provide a program for enabling the processor to function as one or more structural elements. Alternatively, a readable recording medium containing the program can be provided.

[0239] In addition, Figure 19 In the smartphone 900 shown, for example, reference Figure 4 The wireless communication unit 220 can be implemented by a wireless communication interface 912 (e.g., RF circuit 914). Furthermore, the antenna unit 210 can be implemented by an antenna 916. Additionally, the storage unit 230 can be implemented by a memory module 902.

[0240] (Second application example)

[0241] Figure 20 A block diagram illustrating an example of a schematic configuration of a car navigation device 920 to which the technology according to this disclosure can be applied is shown. The car navigation device 920 includes a processor 921, a memory 922, a Global Positioning System (GPS) 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, a wireless communication interface 933, one or more antenna switches 936, one or more antennas 937, and a battery 938.

[0242] The processor 921 may be, for example, a CPU or a SoC, that controls the navigation functions and other functions of the car navigation device 920. The memory 922 includes RAM and ROM, which store programs and data executed by the processor 921.

[0243] GPS module 924 uses GPS signals received from GPS satellites to measure the location (e.g., latitude, longitude, and altitude) of vehicle navigation device 920. Sensor 925 may include a sensor group including, for example, a gyroscope sensor, a geomagnetic sensor, a barometric pressure sensor, etc. Data interface 926 connects to vehicle network 941, for example, via a terminal not shown, to acquire data such as vehicle speed data generated on the vehicle side.

[0244] Content player 927 reproduces content stored on a storage medium (e.g., CD or DVD) inserted into storage medium interface 928. Input device 929 includes, for example, a touch sensor, buttons, switches, etc., to detect if the screen of display device 930 is touched, and accepts user input operations or information. Display device 930 includes a screen such as an LCD or OLED display, displaying images of navigation functions or reproduced content. Speaker 931 outputs sound for navigation functions or reproduced content.

[0245] The wireless communication interface 933 supports cellular communication systems such as LTE or LTE-Advanced and performs wireless communication. The wireless communication interface 933 typically includes a BB processor 934, RF circuitry 935, etc. The BB processor 934 can perform, for example, encoding / decoding, modulation / demodulation, multiplexing / demultiplexing, and various types of signal processing for wireless communication. On the other hand, the RF circuitry 935 can include mixers, filters, amplifiers, etc., to transmit and receive wireless signals via antenna 937. The wireless communication interface 933 can be a single-chip module, where the BB processor 934 and RF circuitry 935 are integrated together. The wireless communication interface 933 can include, for example, Figure 20 The diagram shows multiple BB processors 934 and multiple RF circuits 935. Note that... Figure 20 Although an example is shown in which the wireless communication interface 933 includes multiple BB processors 934 and multiple RF circuits 935, the wireless communication interface 933 may also include a single BB processor 934 or a single RF circuit 935.

[0246] In addition to cellular communication systems, wireless communication interface 933 can also support other types of wireless communication systems, such as short-range wireless communication systems, near-field communication systems, and wireless LAN systems. In this case, wireless communication interface 933 may include BB processor 934 and RF circuit 935 for each wireless communication system.

[0247] Each antenna switch 936 switches the connection target of antenna 937 among multiple circuits (e.g., circuits for different wireless communication systems) included in the wireless communication interface 933.

[0248] Each antenna 937 includes one or more antenna elements (e.g., multiple antenna elements constituting a MIMO antenna) for transmitting and receiving wireless signals via a wireless communication interface 933. The car navigation device 920 may include, for example... Figure 20 The multiple antennas 937 are shown. Note that... Figure 20 Although an example of a car navigation device 920 including multiple antennas 937 is shown, the car navigation device 920 may also include a single antenna 937.

[0249] Furthermore, the car navigation device 920 may include an antenna 937 for various wireless communication systems. In this case, the antenna switch 936 can be omitted from the configuration of the car navigation device 920.

[0250] Battery 938 passed Figure 20 The power supply lines, illustrated by the dashed lines, provide power to each section of the car navigation device 920 shown in the diagram. Additionally, the battery 938 stores power supplied from the vehicle.

[0251] exist Figure 20 In the car navigation device 920 shown, refer to Figure 4 One or more structural elements included in the processing unit 240 (acquisition unit 241 and / or selection support unit 243) may be implemented by the wireless communication interface 933. Alternatively, at least some of these structural elements may be implemented by the processor 921. As an example, a module including a portion (e.g., BB processor 934) or all of the wireless communication interface 933 and / or processor 921 may be installed in the car navigation device 920, and one or more structural elements may be implemented by this module. In this case, the module may store a program for enabling the processor to function as one or more structural elements (i.e., a program for enabling the processor to perform operations of one or more structural elements), and may execute the program. As another example, a program for enabling the processor to function as one or more structural elements may be installed in the car navigation device 920, and the wireless communication interface 933 (e.g., BB processor 934) and / or processor 921 may execute the program. As described above, the car navigation device 920 or the module may be provided as an apparatus including one or more structural elements, and a program for enabling the processor to function as one or more structural elements may be provided. Additionally, a readable recording medium in which the program is recorded may be provided.

[0252] In addition, Figure 20 In the car navigation device 920 shown, for example, referring to Figure 4 The wireless communication unit 220 can be implemented by a wireless communication interface 933 (e.g., RF circuit 935). Furthermore, the antenna unit 210 can be implemented by an antenna 937. Additionally, the storage unit 230 can be implemented by a memory module 922.

[0253] The technology disclosed herein can also be implemented as an in-vehicle system (or vehicle) 940 including one or more blocks of a car navigation device 920, an in-vehicle network 941, and a vehicle module 942. In other words, the in-vehicle system (or vehicle) 940 can be provided as an apparatus including an acquisition unit 241 and / or a selection support unit 243. The vehicle module 942 generates vehicle data (e.g., vehicle speed, engine speed, and fault information) and outputs the generated data to the in-vehicle network 941.

[0254] <<8. Summary>>

[0255] Reference above Figures 1 to 20 Embodiments of this disclosure are described in detail. As described above, terminal device 20 obtains configuration information from base station 10 and transmits uplink RSs using the primary CC of at least one uplink RS in an uplink RS group for selecting the beam used by base station 10 in downlink transmission. This uplink RS group includes multiple CCs indicated by the configuration information. Base station 10 can select a suitable transmission beam for terminal device 20 based on measurements of the uplink RSs. Furthermore, since uplink RSs are transmitted only on the primary CCs of the uplink RS in the uplink RS group, the power consumption of terminal device 20 can be reduced compared to transmitting uplink RSs on all of a large number of CCs in the millimeter-wave band. With this configuration, effective beam selection can be achieved, thus enabling base station 10 to achieve effective carrier aggregation in the millimeter-wave band and improving traffic capacity efficiency in the cellular network.

[0256] Preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, but the present disclosure is not limited to the examples described above. Various changes and modifications will be found by those skilled in the art within the scope of the appended claims, and it should be understood that such changes and modifications will naturally fall within the technical scope of the present disclosure.

[0257] For example, the embodiments of this disclosure can be appropriately combined.

[0258] Note that the processes described in this specification need not be executed in the order shown in the flowcharts and timing diagrams. Some processing steps can be executed in parallel. Furthermore, additional steps may be used, or some processing steps may be omitted.

[0259] Furthermore, the effects described in this specification are merely illustrative or exemplary, and not restrictive. That is, other effects that are apparent to those skilled in the art can be achieved from the description of this specification by utilizing or replacing the above-described effects, based on the technology of this disclosure.

[0260] Alternatively, this technology can also be configured as follows.

[0261] (1) An apparatus comprising:

[0262] The acquisition unit is configured to acquire setting information from the base station; and

[0263] The selection support unit is configured to transmit an uplink reference signal using at least one first unit band comprising a group of multiple unit bands indicated by the setting information, the uplink reference signal being used to select the beam used by the base station in downlink transmission.

[0264] (2) The apparatus of claim (1), wherein the selection support unit uses one or more beams selected based on the uplink reference signal to transmit measurement information about the downlink reference signal transmitted by the base station to the base station.

[0265] (3) The apparatus according to claim (2), wherein the information about the measurement is transmitted using the first unit frequency band.

[0266] (4) The apparatus according to any one of claims (1) to (3), wherein the selection support unit sends to the base station capability information indicating a unit frequency band available for use by the apparatus.

[0267] (5) The apparatus according to claim (4), wherein the capability information includes information indicating available groups and available unit frequency bands of the group.

[0268] (6) The apparatus according to any one of claims (1) to (5), wherein the selection support unit transmits the uplink reference signal using a portion of the first unit frequency band and concentrates the transmission power of the level corresponding to another frequency band in the portion of the frequency band.

[0269] (7) The apparatus of claim (6), wherein the selection support unit concentrates the transmission power corresponding to the level of the second unit band in the portion of the band, the second unit band being different from the first unit band included in the group.

[0270] (8) The apparatus according to claim (6) or (7), wherein the portion of the frequency band is a subcarrier.

[0271] (9) The apparatus according to claim (8), wherein the selection support unit concentrates the transmission power of the remaining frequency band on another portion of the frequency band of the one subcarrier.

[0272] (10) The apparatus according to any one of claims (1) to (9), wherein the group includes some unit bands that can be used in the plurality of unit bands of the base station.

[0273] (11) The apparatus according to any one of claims (1) to (10), wherein the unit frequency band is a component carrier.

[0274] (12) The apparatus according to any one of claims (1) to (11), wherein the unit frequency band has a frequency of 6 GHz or higher.

[0275] (13) An apparatus comprising:

[0276] The setting unit is configured to send setting information to the terminal device indicating at least one first unit frequency band of a group comprising multiple unit frequency bands; and

[0277] The selection unit is configured to select the beam used in downlink transmission based on the measurement results of the uplink reference signal transmitted by the terminal device using the first unit frequency band.

[0278] (14) The apparatus of claim (13), wherein the selection unit transmits a downlink reference signal using a selected beam.

[0279] (15) The apparatus of claim (14), wherein the selection unit uses all of the plurality of unit frequency bands included in the group to transmit the downlink reference signal.

[0280] (16) The apparatus of claim (15), wherein the selection unit selects the beam used in the downlink transmission based on information about the measurement of the downlink reference signal made by the terminal device.

[0281] (17) The apparatus according to any one of claims (13) to (16), wherein the setting unit variably sets the first unit frequency band for each terminal device.

[0282] (18) The apparatus according to claim (17), wherein the setting unit selects the first unit frequency band based on capability information indicating a unit frequency band available for use with the terminal device.

[0283] (19) A method comprising:

[0284] Obtain settings information from the base station; and

[0285] Using at least one first unit frequency band comprising a group of multiple unit frequency bands indicated by the setting information, an uplink reference signal for selecting the beam used by the base station in downlink transmission is transmitted by a processor.

[0286] (20) A method comprising:

[0287] The setting information indicating at least one first unit frequency band of a group comprising multiple unit frequency bands is sent to the terminal device; and

[0288] Based on the measurement results of the uplink reference signal transmitted by the terminal device using the first unit frequency band, the processor selects the beam used in the downlink transmission.

[0289] Reference tag list

[0290] 1 system

[0291] 10 base stations

[0292] 11 Small Cellular Cells

[0293] 15 Core Network

[0294] 16 Packet Data Network

[0295] 20 Terminal devices

[0296] 30 Communication control device

[0297] 31 Macrocell

[0298] 110 antenna elements

[0299] 120 wireless communication units

[0300] 130 Network Communication Unit

[0301] 140 storage units

[0302] 150 processing units

[0303] 151 Setting Units

[0304] 153 Select Unit

[0305] 210 antenna elements

[0306] 220 Wireless Communication Units

[0307] 230 storage units

[0308] 240 processing units

[0309] 241 Acquisition Unit

[0310] 243 Select support unit.

Claims

1. An apparatus comprising: The acquisition unit is configured to acquire setting information from the base station; and The selection support unit is configured to transmit an uplink reference signal using a first unit band from a group of multiple unit bands indicated by the setting information, without using a second unit band other than the first unit band included in the group. The uplink reference signal is used to select the beam to be used by the base station in downlink transmission.

2. The apparatus according to claim 1, wherein, The selection support unit uses one or more beams selected based on the uplink reference signal to transmit information about measurements of the downlink reference signal transmitted by the base station to the base station.

3. The apparatus according to claim 2, wherein, The information about the measurement is transmitted using the first unit frequency band.

4. The apparatus according to claim 1, wherein, The selection support unit sends information to the base station indicating the capability information of a unit frequency band available for the device.

5. The apparatus according to claim 4, wherein, The capability information includes information indicating the available groups and the available unit frequency bands of that group.

6. The apparatus according to claim 1, wherein, The selection support unit uses a portion of the first unit frequency band to transmit the uplink reference signal, and concentrates the transmission power of the level corresponding to another frequency band in the portion of the frequency band.

7. The apparatus according to claim 6, wherein, The selection support unit concentrates the transmission power corresponding to the level of the second unit frequency band into the portion of the frequency band.

8. The apparatus according to claim 6, wherein, The aforementioned frequency band is a subcarrier.

9. The apparatus according to claim 8, wherein, The selection support unit concentrates the transmission power of the remaining frequency band onto another portion of the frequency band of the one subcarrier.

10. The apparatus according to claim 1, wherein, The group includes some of the multiple unit frequency bands that can be used for base stations.

11. The apparatus according to claim 1, wherein, The unit frequency band is a component carrier.

12. The apparatus according to claim 1, wherein, The unit frequency band has a frequency of 6 GHz or higher.

13. An apparatus comprising: The setting unit is configured to send setting information to the terminal device indicating a first unit frequency band in a group of multiple unit frequency bands; and The selection unit is configured to select the beam to be used in downlink transmission based on the measurement results of the uplink reference signal transmitted by the terminal device using the first unit frequency band and not using the second unit frequency band included in the group other than the first unit frequency band.

14. The apparatus according to claim 13, wherein, The selection unit uses the selected beam to transmit a downlink reference signal.

15. The apparatus according to claim 14, wherein, The selection unit uses all of the plurality of unit frequency bands included in the group to transmit the downlink reference signal.

16. The apparatus according to claim 15, wherein, The selection unit selects the beam to be used in downlink transmission based on information about measurements of the downlink reference signal made by the terminal device.

17. The apparatus according to claim 13, wherein, The setting unit can variably set the first unit frequency band for each terminal device.

18. The apparatus according to claim 17, wherein, The setting unit selects the first unit frequency band based on the capability information indicating that the unit frequency band can be used by the terminal device.

19. A method for performing wireless communication by a terminal device, comprising: Obtain settings information from the base station; and Using a first unit frequency band from a group of multiple unit frequency bands indicated by the setting information, and without using a second unit frequency band other than the first unit frequency band included in the group, an uplink reference signal for selecting the beam to be used by the base station in downlink transmission is transmitted by the processor.

20. A method for performing wireless communication by a base station, comprising: The setting information for the first unit frequency band in a group comprising multiple unit frequency bands is sent to the terminal device. and Based on the measurement results of the uplink reference signal transmitted by the terminal device using the first unit frequency band and not using the second unit frequency band other than the first unit frequency band included in the group, the processor selects the beam to be used in the downlink transmission.

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