Communication device, communication method and recording medium

Abstract

A communication device includes a control unit that switches whether to send a first reference signal using a predetermined resource that is predetermined for sending a reference signal.

Description

Technical Field

[0001] The present disclosure relates to a communication device, a communication method, and a recording medium. Background Art

[0002] The radio access method and wireless network of cellular mobile communication (hereinafter also referred to as "Long Term Evolution (LTE)", "LTE-Advanced (LTE-A)", "LTE-Advanced Pro (LTE-APro)", "New Radio (NR)", "New Radio Access Technology (NRAT)", "Evolved Universal Terrestrial Radio Access (EUTRA)", or "Further EUTRA (FEUTRA)") have been discussed in the Third Generation Partnership Project (3GPP). Note that in the following description, LTE includes LTE-A, LTE-APro and EUTRA, and NR includes the fifth generation of mobile wireless communications (5G), NRAT and FEUTRA. In LTE and NR, the base station device (base station) is also called evolved NodeB (eNodeB), and the terminal device (mobile station, mobile station device or terminal) is also called user equipment (UE). LTE and NR are cellular communication systems in which multiple areas covered by base station devices are arranged in a honeycomb shape. A single base station device can manage multiple cells.

[0003] As the next generation radio access method of LTE, NR is a radio access technology (RAT) different from LTE. NR is an access technology that can support various use cases including enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). NR is discussed in terms of the technical architecture corresponding to the usage scenarios, requirements, and deployment scenarios under these use cases.

[0004] One of the technologies discussed in NR is the transmission equalization technology. A typical equalization technology enables a receiving terminal to perform reception equalization by adding a reference signal for channel estimation to a data signal and transmitting the data signal. On the other hand, transmission equalization is a technology that eliminates the need for reception equalization by performing a transmission equalization process in advance in the transmission process to compensate for changes in the amplitude and / or phase received from the communication channel. For example, the details of the technology for transmission equalization are disclosed in the following patent document 1.

[0005] Citation List

[0006] Patent Literature

[0007] Patent Document 1: JP 2018-157374 A Summary of the invention

[0008] Technical issues

[0009] However, the technology proposed in the above-mentioned Patent Document 1 has just been developed, and it is difficult to say that the technology fully satisfies the improvement in the transmission efficiency of the entire system required in NR.

[0010] Therefore, the present disclosure proposes a mechanism that can further improve the transmission efficiency of the entire system.

[0011] Solution to the problem

[0012] According to the present disclosure, a communication device is provided, the communication device including: a control unit, the control unit switching whether to use a predetermined resource predetermined for sending a reference signal to send a first reference signal.

[0013] Furthermore, according to the present disclosure, there is provided a communication device including: a control unit that performs reception processing corresponding to whether a first reference signal is transmitted using a predetermined resource predetermined for transmitting the reference signal.

[0014] Furthermore, according to the present disclosure, there is provided a communication method, the communication method including: using a processor, switching whether to send a first reference signal using a predetermined resource predetermined for sending a reference signal.

[0015] Furthermore, according to the present disclosure, there is provided a communication method, the communication method including: using a processor, performing reception processing corresponding to whether a first reference signal is transmitted using a predetermined resource predetermined for transmitting the reference signal.

[0016] Furthermore, according to the present disclosure, there is provided a recording medium including a program that causes a computer to function as a control unit that switches whether to transmit a first reference signal using a predetermined resource predetermined for transmitting a reference signal.

[0017] Furthermore, according to the present disclosure, there is provided a recording medium including a program that causes a computer to function as a control unit that performs reception processing corresponding to whether a first reference signal is transmitted using a predetermined resource predetermined for transmitting the reference signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram for explaining reception equalization.

[0019] Figure 2 It is a diagram for explaining transmission equalization.

[0020] Figure 3 is a diagram illustrating the overall configuration of a communication system according to an embodiment of the present disclosure.

[0021] Figure 4is a block diagram illustrating an example of the configuration of a first communication device according to the present embodiment.

[0022] Figure 5 is a block diagram illustrating an example of the configuration of the second communication device according to the present embodiment.

[0023] Figure 6 is a block diagram illustrating an example of the configuration of a communication control device according to the present embodiment.

[0024] Figure 7 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0025] Figure 8 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0026] Fig. 9 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0027] Fig.10 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0028] Fig.11 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0029] Fig.12 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0030] Fig.13 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0031] Fig.14 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0032] Fig.15 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0033] Fig.16 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0034] Fig.17 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0035] Fig.18 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0036] Fig.19 : is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system according to the present embodiment.

[0037] Fig. 20 is a block diagram illustrating an example of a schematic configuration of a server.

[0038] Fig.21 is a block diagram illustrating a first example of a schematic configuration of an eNB.

[0039] Fig. 22 is a block diagram illustrating a second example of a schematic configuration of an eNB.

[0040] Fig.23 It is a block diagram illustrating an example of a schematic configuration of a smart phone.

[0041] Fig.24 is a block diagram illustrating an example of a schematic configuration of a car-mounted navigation device. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Note that in this specification and the accompanying drawings, repeated descriptions of components having substantially the same functional configurations are omitted by assigning the same reference numerals.

[0043] Note that the description will be made in the following order.

[0044] 1. Introduction

[0045] 1.1. Receive and transmit equalization

[0046] 1.2. Overview of the proposed technology

[0047] 2. Composition Example

[0048] 2.1. Example of the entire system configuration

[0049] 2.2. Configuration example of the first communication device

[0050] 2.3. Configuration example of the second communication device

[0051] 2.4. Example of communication control equipment configuration

[0052] 3. Technical features

[0053] 3.1. Switching between sending and not sending reference signals

[0054] 3.2. Notification of setting information

[0055] 3.3. Switching based on conditional judgment

[0056] 4. Application examples

[0057] 5. Conclusion

[0058] <<1. Introduction>>

[0059] <1.1. Receive and transmit balance>

[0060] Equalization is to restore the signal to the original signal by multiplying the signal whose amplitude and / or phase is changed by the communication channel by, for example, the inverse matrix of the channel. Figure 1 and Figure 2 Describe receive equalization and transmit equalization.

[0061] Figure 1 is a diagram for explaining reception equalization. Figure 1 As shown in the diagram, when the transmitter transmits a transmission signal s, and the transmission signal propagates through the communication channel H and is received by the receiver, the received signal becomes Hs. In the case of reception equalization in which equalization is performed by the receiver, the receiver estimates the inverse matrix H of the communication channel H. -1 , and multiply the received signal Hs by the inverse matrix H -1 , thereby decoding the transmitted signal s.

[0062] Figure 2 is a diagram for explaining transmission equalization. Figure 2 As shown in the diagram, the transmitter sends the signal s by multiplying the inverse matrix H of the pre-estimated communication channel H -1 The transmitted signal H -1 s. When sending signal H -1 When s propagates through the communication channel H and is received by the receiver, the received signal becomes s. As described above, equalization is performed in advance on the transmitter side, so that the signal s can be decoded without equalization on the receiver side.

[0063] <1.2. Overview of Proposed Technology>

[0064] The reference signal is used in the estimation of the communication channel performed in the equalization. The communication channel is estimated based on the reception result of the reference signal, and the equalization is performed based on the estimated communication channel.

[0065] Here, if transmission equalization is performed, since the receiving side does not need to perform reception equalization, it can be considered that there is no need to send a reference signal from the transmitter to the receiver. In addition, even if transmission equalization is not performed, as long as the channel change after the channel estimation based on the reference signal is small on the receiving side, reception equalization can be performed by using the past channel estimation results. Even in this case, it is considered that it is not necessary to send the reference signal again and estimate the channel again. In addition, it is considered that there is a case where the transmission of the reference signal can be omitted.

[0066] Therefore, the present disclosure proposes a mechanism capable of switching transmission / non-transmission of a reference signal. As a result, when a reference signal is not always required to decode a transmission signal, transmission of the reference signal is omitted, making it possible to improve the transmission efficiency of the entire system.

[0067] <<2. Example of composition>>

[0068] <2.1. Example of overall system configuration>

[0069] Figure 3 1 is a diagram illustrating the overall configuration of a communication system according to an embodiment of the present disclosure. Figure 3 As shown in the diagram, the communication system 1 includes a base station 10 , a plurality of terminal devices 20 , a core network 30 , and a packet data network (PDN) 40 .

[0070] The base station 10 is a communication device that operates a cell 11 and provides a wireless communication service to one or more terminal devices 20 located in the cell 11. The cell 11 operates in accordance with any wireless communication method such as LTE or NR. The base station 10 is connected to a core network 30. The core network 30 is connected to a packet data network (PDN) 13 via a gateway device (not shown).

[0071] The core network 30 may include a mobility management entity (MME), a serving gateway (S-GW), a PDN gateway (P-GW), a policy and charging rules function (PCRF), and a home subscriber server (HSS). Alternatively, the core network 30 may include an entity of a NR having similar functions. The MME is a control node that processes signals of the control plane and manages the mobility status of the terminal device. The S-GW is a control node that processes signals of the user plane and is a gateway device that switches the transmission path of user data. The P-GW is a control node that processes signals of the user plane and is a gateway device that acts as a connection point between the core network 30 and the PDN 40. The PCRF is a control node that controls policies such as the quality of service (QoS) for the bearer and charging. The HSS is a control node that processes user data and controls services.

[0072] The terminal device 20 is a communication device that performs wireless communication based on the control of the base station 10. The terminal device 20 can perform wireless communication with the base station 10. The communication link in the direction from the base station 10 to the terminal device 20 is also called a downlink, and the terminal device 20 receives a downlink signal from the base station 10. The communication link in the direction from the terminal device 20 to the base station 10 is also called an uplink, and the terminal device 20 sends an uplink signal to the base station 10. In addition, the terminal device 20 can perform wireless communication with other terminal devices 20. The communication link between the terminal devices 20 is also called a side link, and the terminal device 20 sends and receives side link signals to and from other terminal devices 20.

[0073] Here, each device included in the communication system 1 may be referred to as Figure 4-Figure 6 The role of the first communication device 100, the second communication device 200, or the communication control device 300 is described in detail.

[0074] The first communication device 100 is a communication device that switches whether to send a reference signal and sends the reference signal according to the switching result. Hereinafter, the reference signal sent by the first communication device 100 may also be referred to as a first reference signal. The second communication device 200 is a communication device that receives the first reference signal sent from the first communication device 100. However, the second communication device 200 may also send a reference signal. Hereinafter, the reference signal sent by the second communication device 200 may also be referred to as a second reference signal. The second reference signal can be used to determine the switching of sending / not sending the first reference signal. The communication control device 300 is a device that performs settings related to the switching of sending / not sending the reference signal performed by the first communication device 100.

[0075] In uplink communication and downlink communication, one of the base station 10 and the terminal device 20 functions as the first communication device 100, and the other functions as the second communication device 200. The device that functions as the communication control device 300 in uplink communication and downlink communication is typically the base station 10. In addition, for example, any entity within the core network 30 may function as the communication control device 300.

[0076] In the sidelink communication, one of the terminal devices 20 performing the sidelink communication functions as the first communication device 100, and the other functions as the second communication device 200. The device that functions as the communication control device 300 in the sidelink communication is typically the base station 10 or the terminal device 20. In addition, for example, any entity within the core network 30 may function as the communication control device 300.

[0077] Note that the device that functions as the first communication device 100 and the device that functions as the second communication device 200 may be switched appropriately. For example, at a first time, the base station 10 may function as the first communication device 100, and the terminal device 20 may function as the second communication device 200. Subsequently, at a second time, the terminal device 20 may function as the first communication device 100, and the base station 10 may function as the second communication device 200.

[0078] <2.2. Configuration Example of First Communication Device>

[0079] Figure 4 1 is a block diagram illustrating an example of the configuration of the first communication device 100 according to the present embodiment. Figure 4 , the first communication device 100 includes an antenna unit 110, a wireless communication unit 120, a storage unit 130 and a control unit 140.

[0080] (1) Antenna unit 110

[0081] The antenna unit 110 transmits the signal output by the wireless communication unit 120 into the space in the form of radio waves. In addition, the antenna unit 110 converts the radio waves in the space into signals and outputs the signals to the wireless communication unit 120.

[0082] (2) Wireless communication unit 120

[0083] The wireless communication unit 120 transmits and receives signals. For example, the wireless communication unit 120 transmits and receives signals to and from the second communication device 200.

[0084] (3) Storage unit 130

[0085] The storage unit 130 temporarily or permanently stores programs and various data used for operations of the first communication device 100 .

[0086] (4) Control unit 140

[0087] The control unit 140 controls the operation of the entire first communication device 100 and provides various functions of the first communication device 100. The control unit 140 includes a notification unit 141 and a communication control unit 143. The communication unit 141 has a function of notifying the communication control device 300 of information on the switching of the transmission / non-transmission of the reference signal of the first communication device 100. The communication control unit 143 has a function of controlling the communication processing of the first communication device 100. In particular, the communication control unit 143 switches the transmission / non-transmission of the reference signal according to the control of the communication control device 300. Note that the control unit 140 may also include components other than these components. That is, the control unit 140 may also exhibit functions other than the functions of these components.

[0088] (5) Supplement

[0089] The first communication device 100 may further include a network communication unit for communicating with the communication control device 300. For example, when the base station 10 functions as the first communication device 100 and the communication control device 300, the network communication unit performs communication within the base station 10. As another example, when the base station 10 functions as the communication control device 300 and the terminal device 20 functions as the first communication device 100, the function as the network communication unit is implemented by the wireless communication unit 120.

[0090] <2.3. Configuration Example of Second Communication Device>

[0091] Figure 5 2 is a block diagram illustrating an example of the configuration of the second communication device 200 according to the present embodiment. Figure 5 , the second communication device 200 includes an antenna unit 210, a wireless communication unit 220, a storage unit 230 and a control unit 240.

[0092] (1) Antenna unit 210

[0093] The antenna unit 210 transmits the signal output by the wireless communication unit 220 into the space in the form of radio waves. In addition, the antenna unit 210 converts the radio waves in the space into signals and outputs the signals to the wireless communication unit 220.

[0094] (2) Wireless communication unit 220

[0095] The wireless communication unit 220 transmits and receives signals. For example, the wireless communication unit 220 transmits and receives signals to and from the first communication device 100.

[0096] (3) Storage unit 230

[0097] The storage unit 230 temporarily or permanently stores programs and various data for operations of the second communication device 200 .

[0098] (4) Control unit 240

[0099] The control unit 240 controls the operation of the entire second communication device 200 and provides various functions of the second communication device 200. The control unit 240 includes a communication control unit 241. The communication control unit 241 has a function of controlling the communication processing of the second communication device 200. In particular, the communication control unit 241 performs a reception process corresponding to the switching of the transmission / non-transmission of the reference signal performed by the first communication device 100. Note that the control unit 240 may also include components other than these components. That is, the control unit 240 may also exhibit functions other than the functions of these components.

[0100] <2.4. Example of Communication Control Device Configuration>

[0101] Figure 6 1 is a block diagram illustrating an example of the configuration of the communication control device 300 according to the present embodiment. Figure 6 , the communication control device 300 includes a communication unit 310 , a storage unit 320 , and a control unit 330 .

[0102] (1) Communication unit 310

[0103] The communication unit 310 transmits and receives signals. For example, the communication unit 310 transmits and receives signals to and from the first communication device 100.

[0104] (2) Storage unit 320

[0105] The storage unit 320 temporarily or permanently stores programs and various data used for the operation of the communication control device 300 .

[0106] (3) Control unit 330

[0107] The control unit 330 controls the operation of the entire communication control device 300 and provides various functions of the communication control device 300. The control unit 330 includes a notification unit 331. The notification unit 331 has a function of notifying the first communication device 100 under control of various information. In particular, the notification unit 331 notifies the first communication device 100 of setting information on switching of transmission / non-transmission of a reference signal. Note that the control unit 330 may also include components other than these components. That is, the control unit 330 may also exhibit functions other than the functions of these components.

[0108] <<3. Technical Features>>

[0109] <3.1. Switching between sending and not sending reference signals>

[0110] (1) Processing performed by the first communication device 100

[0111] The first communication device 100 (e.g., the notification unit 141) transmits capability information about switching whether to use a predetermined resource reserved for transmitting a reference signal to transmit a first reference signal to the communication control device 300. The capability information includes at least information showing whether the first communication device 100 is capable of switching transmission / non-transmission of the first reference signal. In addition, the capability information may include type information of a channel in which the first communication device 100 is capable of switching transmission / non-transmission of the first reference signal, and identification information of the predetermined resource.

[0112] The scheduled resource is a resource reserved in advance for transmitting a reference signal. For example, as the scheduled resource, a plurality of resource elements are reserved in a unit resource including a scheduled frequency resource (eg, a resource block) and a scheduled time resource (eg, a time slot or a subframe).

[0113] The first communication device 100 (e.g., the communication control unit 143) switches whether to use a predetermined resource reserved for sending the first reference signal to send the first reference signal. That is, the first communication device 100 switches between sending a signal including the first reference signal in the predetermined resource and sending a signal not including the first reference signal in the predetermined resource. The switching of sending / not sending the first reference signal can be performed for multiple predetermined resources (e.g., for each unit resource). For example, the first communication device 100 can send the first parameter signal in all predetermined resources included in the unit resource, and switch between not sending the first reference signal in at least a part of the predetermined resources included in the unit resource. When the first communication device 100 communicates with multiple second communication devices 200, switching can be performed for each second communication device 200.

[0114] The first communication device 100 measures the second reference signal transmitted from the second communication device 200, estimates the communication channel between the first communication device 100 and the second communication device 200, and acquires channel information. The first communication device 100 performs reception equalization based on the acquired channel information. In addition, the first communication device 100 can perform transmission equalization based on the acquired channel information.

[0115] Typically, the first communication device 100 performs transmission equalization without transmitting the first reference signal in the predetermined resource. For transmission equalization, channel information obtained based on the second reference signal transmitted from the second communication device 200 is used. When transmission equalization is performed, the second communication device 200 can decode the transmission signal without receiving equalization. Even if the first reference signal is not transmitted in the predetermined resource, the first communication device 100 may not perform transmission equalization. In this case, in the second communication device 200, receiving equalization is performed based on the channel information obtained from the first reference signal previously transmitted from the first communication device 100.

[0116] The first communication device 100 may perform zero-power transmission in a predetermined resource in which the first reference signal is not transmitted. In this case, power consumption may be suppressed. In addition, the first communication device 100 may use a predetermined resource in which the first reference signal is not transmitted as another transmission channel. In this case, frequency efficiency may be improved.

[0117] (2) Processing by the second communication device 200

[0118] The second communication device 200 (eg, the communication control unit 241) transmits the second reference signal using a predetermined resource reserved for transmitting a reference signal. That is, the second communication device 200 transmits a signal including the second reference signal in the predetermined resource. As a result, the first communication device 100 can acquire channel information.

[0119] The second communication device 200 (for example, the communication control unit 241) performs reception processing corresponding to whether the first reference signal is sent in the predetermined resource. For example, the second communication device 200 determines whether the first reference signal is sent in the predetermined resource. When the first reference signal is sent in the predetermined resource, the second communication device 200 performs reception equalization based on the channel information obtained from the first reference signal. On the other hand, when it is determined that the first reference signal is not sent in the predetermined resource, the second communication device 200 determines whether transmission equalization is completed. Subsequently, when transmission equalization is completed, the second communication device 200 simply processes the received signal into a decoded transmission signal. On the other hand, when transmission equalization is not completed, reception equalization is performed based on the channel information obtained from the previously transmitted first reference signal.

[0120] When performing reception equalization, the second communication device 200 selects which first reference signal to use for reception equalization. Typically, the second communication device 200 uses the first reference signal received most recently. This is because it is assumed that the channel changes less than other reference signals.

[0121] The second communication device 200 acquires information for reception processing from the first communication device 100 or the communication control device 300. The information for reception processing may be, for example, information showing whether the first reference signal is transmitted in the predetermined resource, and information showing whether transmission equalization is performed when the first reference signal is not transmitted in the predetermined resource. In addition, the information for reception processing may be, for example, information for determining whether the first reference signal is transmitted in the predetermined resource, and information for determining whether transmission equalization is performed when the first reference signal is not transmitted in the predetermined resource. Specifically, the information for reception processing may be setting information described later. The setting information may be notified directly from the communication control device 300, or may be notified indirectly via the first communication device 100.

[0122] (3) Example of scheduled resources

[0123] In the communication in the first direction, the transmission of the first reference signal using the predetermined resources is not performed, and in the communication in the second direction opposite to the first direction, the transmission of the second reference signal using the predetermined resources may be performed. The first direction and the second direction are respectively downlink and uplink, uplink and downlink, or side link and side link. For example, the second reference signal may be transmitted on the downlink, and the transmission / non-transmission of the first reference signal may be switched on the uplink. As another example, the second reference signal may be transmitted on the uplink, and the transmission / non-transmission of the first reference signal may be switched on the downlink. As another example, the second reference signal may be transmitted in the first direction of the side link, and the transmission / non-transmission of the first reference signal may be switched in the second direction of the side link. Note that the predetermined resources of the downlink, uplink, or side link may be determined by the TDD configuration or the slot format indicator.

[0124] Instead of sending a reference signal using a predetermined resource within a resource for a first purpose, sending a reference signal using a predetermined resource within a resource for a second purpose different from the first purpose may be performed. The resources for the first purpose and the resources for the second purpose are control resources and data resources, or data resources and control resources, respectively. For example, a second reference signal may be sent in a control resource, and sending / not sending of a first reference signal may be switched in a data resource. As another example, a second reference signal may be sent in a data resource, and sending / not sending of a first reference signal may be switched in a control resource. As a specific example, the second communication device 200 sends a data signal including a second reference signal using a data resource, and the first communication device 100 switches whether to include the first reference signal in a reception response (ACK / NACK) to the data signal. Examples of control resources include a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), and a physical sidelink control channel (PSCCH). Examples of resources for data include a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and a physical sidelink shared channel (PSSCH).

[0125] Reference signal example

[0126] The reference signal is a demodulation reference signal (DM-RS), a phase tracking reference signal (PT-RS), a sounding reference signal (SRS), or a channel state information reference signal (CSI-RS).

[0127] <3.2. Notification of setting information>

[0128] The communication control device 300 notifies the first communication device 100 of setting information for controlling whether to transmit the first reference signal using a predetermined resource in the first communication device 100. The communication control device 300 generates the setting information by referring to the capability information of the first communication device 100.

[0129] For notification of the setting information, for example, system information, RRC signaling, MAC control element (CE), or downlink control information (DCI) may be used.

[0130] (1) Setting information including explicit switching instructions

[0131] The setting information may include an explicit switching indication regarding whether the first communication device 100 uses a predetermined resource to send the first reference signal. In this case, the first communication device 100 switches the sending / non-sending of the first reference signal according to the explicit switching indication in the setting information. The setting information regarding the explicit switching indication will be described below.

[0132] The setting information may include information indicating whether to use a predetermined resource to transmit the first reference signal. The first communication device 100 switches transmission / non-transmission of the first reference signal according to the instruction.

[0133] The setting information may include information indicating the type of channel indicated as not used to send the first reference signal. In the channel of the indicated type, the first communication device 100 does not use the predetermined resources to send the first reference signal. It may be indicated that PDSCH, PDCCH, PUSCH, PUCCH, PSSCH and PSCCH are not used to send the first reference signal.

[0134] The setting information may include identification information of a predetermined resource indicated not to be used for sending the first reference signal. In the indicated predetermined resource, the first communication device 100 does not send the first reference signal. For example, the identification information may be a subcarrier index, a symbol index, or a time slot index.

[0135] (2) Setting information including implicit switching instructions

[0136] The setting information may include an implicit switching indication regarding whether the first communication device 100 uses a predetermined resource to send the first reference signal. In this case, the first communication device 100 switches the sending / non-sending of the first reference signal based on the implicit indication in the setting information. The setting information regarding the implicit switching indication will be described below.

[0137] The setting information may include information showing a reference for switching whether to use a predetermined resource to send the first reference signal. The first communication device 100 makes a conditional determination based on the notified setting information, and switches the transmission / non-transmission of the first reference signal according to the determination result. The information notified as the setting information and the details of the switching based on the conditional determination will be described in detail in the next section.

[0138] <3.3. Switching based on conditional judgment>

[0139] The first communication device 100 switches whether to transmit the first reference signal using a predetermined resource based on the setting information including the implicit switching instruction notified from the communication control device 300 .

[0140] In particular, the first communication device 100 (e.g., the communication control unit 143) switches whether to use a predetermined resource to send a first reference signal based on pre-acquired channel information. Here, the channel information is information showing the characteristics of the communication channel between the first communication device 100 and the second communication device 200. For example, when the channel information is acquired in advance and transmission equalization based on the channel information is possible, the first communication device 100 does not send the first reference signal, otherwise it sends the first reference signal. As another example, when the second communication device 200 acquires the channel information in advance and reception equalization based on the channel information is possible, the first communication device 100 does not send the first reference signal, otherwise it sends the first reference signal. In any case, the second communication device 200 is able to obtain the equalized transmission signal.

[0141] An example of a switching reference is described below. Note that a plurality of switching references may be used in combination.

[0142] (1) Switching based on the elapsed time since the second reference signal was received

[0143] The first communication device 100 can switch whether to use the predetermined resources to send the first reference signal based on the elapsed time since the second reference signal was received from the second communication device 200 as the communication partner. Specifically, the first communication device 100 pre-acquires channel information based on the second reference signal. Subsequently, the first communication device 100 sends a signal that completes the transmission equalization without including the first reference signal until the elapsed time exceeds a predetermined threshold. In this case, the first communication device 100 can use the pre-acquired channel information to perform transmission equalization. When the elapsed time since the channel estimation based on the second reference signal is short, it is assumed that there are fewer changes in the channel, so that transmission equalization can be performed by diverting the pre-acquired channel information. On the other hand, when the elapsed time exceeds the predetermined threshold, the first communication device 100 sends a signal including the first reference signal.

[0144] For example, based on the elapsed time until a reception response (ACK / NACK) including a signal of a second reference signal is sent, the first communication device 100 may switch whether to include the first reference signal in the reception response. Specifically, the first communication device 100 acquires channel information based on the second reference signal. Subsequently, the first communication device 100 uses the pre-acquired channel information to perform transmission equalization of the reception response until the elapsed time exceeds a predetermined threshold, and transmits a reception response that completes transmission equalization without including the first reference signal. On the other hand, when the elapsed time exceeds a predetermined threshold, the first communication device 100 transmits a reception response including the first reference signal. The predetermined threshold may be, for example, N time slots, M symbols, or a reception response within the same time slot as the received signal.

[0145] As the setting information, for example, a predetermined threshold value related to the elapsed time until a response is received may be notified.

[0146] refer to Figure 7 and Figure 8 , illustrating an example of the process of switching processing based on reception response time.

[0147] Figure 7 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the second communication device 200 and the communication control device 300, and the terminal device 20 functions as the first communication device 100.

[0148] like Figure 7 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S100). Thereafter, the base station 10 and the terminal device 20 perform an initial access procedure (step S102). Thereafter, the base station 10 notifies the terminal device 20 of setting information, wherein the setting information includes a predetermined threshold value related to the elapsed time until a response is received (step S104). Then, when a packet is generated in the base station 10 (step S106), the base station 10 notifies the terminal device 20 of the DCI (step S108). Note that the above-mentioned setting information may be included in the DCI and notified. Thereafter, the base station 10 sends a data signal including a reference signal A to the terminal device 20 (step S110). Then, the terminal device 20 performs reception equalization using the reference signal A and decodes the data signal (step S112).

[0149] Afterwards, the terminal device 20 determines whether to include the reference signal B in the reception response to the data signal (step S114). The determination is made based on whether the elapsed time from receiving the data signal to sending the reception response exceeds a predetermined threshold notified in the setting information. When it is determined that the reference signal B is not included (step S114 / No), the terminal device 20 uses the reference signal A for transmission equalization (step S116) and sends a reception response after transmission equalization that does not include the reference signal B (step S118). On the other hand, when it is determined that the reference signal B is included (step S114 / Yes), the terminal device 20 sends a reception response including the reference signal B (step S120). Subsequently, the base station 10 uses the reference signal B for reception equalization and decodes the reception response (step S122).

[0150] Figure 81 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the first communication device 100 and the communication control device 300, and the terminal device 20 functions as the second communication device 200.

[0151] like Figure 8 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S130). Thereafter, the base station 10 and the terminal device 20 perform an initial access procedure (step S132). Thereafter, the terminal device 10 notifies the terminal device 20 of setting information including a predetermined threshold value related to the elapsed time until a response is received (step S134). Then, when a packet is generated in the terminal device 20 (step S136), the terminal device 20 notifies the base station 10 of a scheduling request (SR) (step S138). Thereafter, the base station 10 performs scheduling and notifies the terminal device 20 of the DCI (step S140). Thereafter, the terminal device 20 sends a data signal including a reference signal A to the base station 10 (step S142). Then, the base station 10 performs reception equalization using the reference signal A and decodes the data signal (step S144).

[0152] Afterwards, the base station 10 determines whether to include reference signal B in the reception response to the data signal (step S146). The determination is made based on whether the elapsed time from receiving the data signal to sending the reception response exceeds a predetermined threshold notified in the setting information. When it is determined that reference signal B is not included (step S146 / no), the base station 10 uses reference signal A for transmission equalization (step S148) and sends a reception response after transmission equalization that does not include reference signal B (step S150). On the other hand, when it is determined that reference signal B is included (step S146 / yes), the base station 10 sends a reception response including reference signal B (step S152). Subsequently, the terminal device 20 uses reference signal B for reception equalization and decodes the reception response (step S154).

[0153] Note that in steps S150 and S152, instead of receiving a response (ACK / NACK), a DCI for retransmission may be transmitted.

[0154] (2) Switching based on the number of symbols included in a slot

[0155] The first communication device 100 can switch whether to use the predetermined resources to send the first reference signal based on the number of symbols contained in the time slot. For example, when the number of symbols contained in one time slot is greater than a predetermined threshold, the first communication device 100 uses the predetermined resources to send the first reference signal. On the other hand, when the number of symbols contained in one time slot is small, the first communication device 100 does not use the predetermined resources to send the first reference signal. In this case, the first communication device 100 can use the pre-acquired channel information for transmission equalization. When the number of symbols in each time slot is small, it is assumed that the time from the channel estimation based on the second reference signal to the transmission of the response is short. Therefore, since it is assumed that the changes in the channel are small, transmission equalization can be performed by diverting the pre-acquired channel information.

[0156] As the setting information, for example, the number of symbols included in a time slot may be notified. As another example, as the setting information, a predetermined threshold value related to the number of symbols included in a time slot may be notified.

[0157] refer to Fig. 9 and Fig.10 , illustrating an example of a process for switching processing based on the number of symbols included in a time slot.

[0158] Fig. 9 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the second communication device 200 and the communication control device 300, and the terminal device 20 functions as the first communication device 100.

[0159] like Fig. 9 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S160). After that, the base station 10 and the terminal device 20 perform an initial access process (step S162). After that, the base station 10 notifies the terminal device 20 of setting information including the number of symbols contained in the time slot (step S164). Then, when a packet is generated in the base station 10 (step S166), the base station 10 notifies the terminal device 20 of the DCI (step S168). Note that the above-mentioned setting information may be included in the DCI and notified. After that, the base station 10 sends a data signal including a reference signal A to the terminal device 20 (step S170). Then, the terminal device 20 uses the reference signal A for reception equalization and decodes the data signal (step S172).

[0160] Afterwards, the terminal device 20 determines whether to include the reference signal B in the reception response to the data signal (step S174). The determination is made based on whether the number of symbols contained in the time slot notified in the setting information exceeds a predetermined threshold. When it is determined that the reference signal B is not included (step S174 / No), the terminal device 20 uses the reference signal A for transmission equalization (step S176) and sends a reception response after transmission equalization that does not include the reference signal B (step S178). On the other hand, when it is determined that the reference signal B is included (step S174 / Yes), the terminal device 20 sends a reception response including the reference signal B (step S180). Subsequently, the base station 10 uses the reference signal B for reception equalization and decodes the reception response (step S182).

[0161] Fig.10 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the first communication device 100 and the communication control device 300, and the terminal device 20 functions as the second communication device 200.

[0162] like Fig.10 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S190). After that, the base station 10 and the terminal device 20 perform an initial access process (step S192). After that, the base station 10 notifies the terminal device 20 of setting information including the number of symbols contained in the time slot (step S194). Then, when a packet is generated in the terminal device 20 (step S196), the terminal device 20 notifies the base station 10 of a scheduling request (SR) (step S198). After that, the base station 10 performs scheduling and notifies the terminal device 20 of the DCI (step S200). After that, the terminal device 20 sends a data signal including a reference signal A to the base station 10 (step S202). Then, the base station 10 uses the reference signal A for reception equalization and decodes the data signal (step S204).

[0163] Afterwards, the base station 10 determines whether to include the reference signal B in the reception response to the data signal (step S206). The determination is made based on whether the number of symbols contained in the time slot notified in the setting information exceeds a predetermined threshold. When it is determined that the reference signal B is not included (step S206 / No), the base station 10 uses the reference signal A for transmission equalization (step S208) and sends a reception response after transmission equalization that does not include the reference signal B (step S210). On the other hand, when it is determined that the reference signal B is included (step S206 / Yes), the base station 10 sends a reception response including the reference signal B (step S212). Subsequently, the terminal device 20 uses the reference signal B for reception equalization and decodes the reception response (step S214).

[0164] Note that in steps S210 and S212, instead of receiving a response (ACK / NACK), a DCI for retransmission may be transmitted.

[0165] (3) Switching based on timer or time interval

[0166] The first communication device 100 may switch whether to use the predetermined resources to send the first reference signal based on whether the predetermined timer has expired or is within the predetermined time interval. Specifically, before the predetermined timer expires or when it is within the predetermined time interval, the first communication device 100 does not use the predetermined resources to send the first reference signal. On the other hand, when the predetermined timer expires or exceeds the predetermined time interval, the first communication device 100 uses the predetermined resources to send the first reference signal. When the elapsed time since the transmission of the first reference signal is short, it is assumed that the change in the channel is small, so that reception equalization and transmission equalization can be performed by stealing the first reference signal that was once transmitted.

[0167] The start timing of the timer or time interval is arbitrary. For example, the start timing may be the timing of sending the first reference signal using the predetermined resources. Specifically, before the predetermined time has passed after sending the first reference signal using the predetermined resources, the first communication device 100 does not send the first reference signal using the predetermined resources. Subsequently, after the predetermined time has passed, the first communication device 100 sends the first reference signal again using the predetermined resources. As another example, the start timing of the timer or time interval may be the timing of receiving the first reference signal by the second communication device 200, or may be the boundary of a time slot.

[0168] As setting information, for example, the length of a timer or time interval, the start timing, etc. can be notified.

[0169] refer to Figure 11-13 , illustrating an example of the process of switching processing based on a timer or time interval.

[0170] Fig.111 is a sequence diagram illustrating an example of a flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as a communication control device 300. In addition, the base station 10 and the terminal device 20 function as a first communication device 100 and a second communication device 200, respectively.

[0171] Specifically, when one of the base station 10 and the terminal device 20 sends a first reference signal, before the timer expires or exceeds a predetermined time interval, neither the base station 10 nor the terminal device 20 uses a predetermined resource to send the first reference signal. Subsequently, after the timer expires or when the predetermined time interval exceeds, one of the base station 10 and the terminal device 20 sends the first reference signal.

[0172] like Fig.11 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S300). Afterwards, the base station 10 and the terminal device 20 perform an initial access process (step S302). Afterwards, the base station 10 notifies the terminal device 20 of the setting information including the setting of the timer or time interval (step S304). Then, when a packet is generated in the base station 10 (step S306), the base station 10 notifies the terminal device 20 of the DCI (step S308). Note that the above-mentioned setting information may be included in the DCI and notified. Afterwards, the base station 10 sends a data signal including a reference signal A to the terminal device 20 (step S310). Afterwards, the terminal device 20 starts the timer (step S312). The timing of the timer start may be the timing of the data signal including the reference signal A having been received, or any other timing. Then, the terminal device 20 uses the reference signal A for reception equalization and decodes the data signal (step S314).

[0173] After that, the terminal device 20 determines whether to include the reference signal B in the reception response to the data signal (step S316). This determination is made based on whether the timer has expired. At the current timing, since the timer has not expired, it is determined that the reference signal B is not included. Therefore, the terminal device 20 performs transmission equalization using the reference signal A (step S318), and transmits a reception response after transmission equalization that does not include the reference signal B (step S320).

[0174] Then, if Fig.12As shown in the diagram, when a packet is generated in the base station 10 (step S322), the base station 10 determines whether to include the reference signal C in the data signal (step S324). The determination is made based on whether the timer has expired. At the current timing, since the timer has not expired, it is determined that the reference signal C is not included. Afterwards, the base station 10 notifies the terminal device 20 of the DCI (step S326). Note that the DCI may include setting information for updating the timer or time interval information. Then, the base station 10 sends the data signal that does not include the reference signal C to the terminal device 20 (step S328). Afterwards, the base station 20 uses the reference signal A received in step S310 for reception equalization and decodes the data signal (step S330).

[0175] After that, the terminal device 20 determines whether to include the reference signal D in the reception response to the data signal (step S332). This determination is made based on whether the timer has expired. At the current timing, since the timer has not expired, it is determined that the reference signal D is not included. Therefore, the terminal device 20 performs transmission equalization using the reference signal A (step S334), and transmits a reception response after transmission equalization that does not include the reference signal D (step S336).

[0176] Afterwards, if Fig.13 As shown in the diagram, the base station 10 detects the expiration of the timer and restarts the timer (step S338). Subsequently, when a packet is generated at the base station 10 (step S340), the base station 10 determines whether to include the reference signal E in the data signal (step S342). The determination is based on whether the timer has expired. At the current timing, since the timer has expired, it is determined that the reference signal E is included. Afterwards, the base station 10 notifies the terminal device 20 of the DCI (step S344). Note that the DCI may include setting information for updating the timer or time interval information. Afterwards, the base station 10 sends the data signal including the reference signal E to the terminal device 20 (step S346). Afterwards, the terminal device 20 uses the reference signal E for reception equalization and decodes the data signal (step S348).

[0177] After that, the terminal device 20 determines whether to include the reference signal F in the reception response to the data signal (step S350). This determination is made based on whether the timer has expired. At the current timing, since the timer has not expired, it is determined that the reference signal F is not included. Therefore, the terminal device 20 performs transmission equalization using the reference signal E (step S352), and transmits a reception response after transmission equalization that does not include the reference signal F (step S354).

[0178] (4) Switching based on the number of repeated transmissions

[0179] The first communication device 100 may switch whether to use a predetermined resource to send a first reference signal based on the number of repeated transmissions. When the number of repeated transmissions is less than a predetermined threshold, the first communication device 100 does not use the predetermined resource to send the first reference signal. For example, when the number of repeated transmissions is less than N, the first communication device 100 uses the predetermined resource to send the first reference signal only for the first time, and does not use the first resource to send the first reference signal after the second time. On the other hand, when the number of repeated transmissions is equal to or greater than the predetermined threshold, the first communication device 100 uses the predetermined resource to send the first reference signal for the first time. Subsequently, the first communication device 100 periodically uses the predetermined resource to send the first reference signal, and does not use the predetermined resource to send the first reference signal at other timings. For example, when the number of repeated transmissions is equal to or greater than N, the first communication device 100 uses the predetermined resource to send the first reference signal for the first time, and uses the first resource to send the first reference signal every predetermined number of times (e.g., every N times) for the second time and thereafter. When the number of repeated transmissions after sending the first reference signal is small, the time elapsed since the transmission of the first reference signal is short, and it is assumed that the change in the channel is small. Therefore, reception equalization can be performed by stealing the first reference signal that was once sent.

[0180] Here, periodic transmission, for example, indicates that the first reference signal is transmitted whenever transmission is repeated twice. When the total number of repeated transmissions is 4 or more, the first reference signal is included in the first transmission, the first reference signal is not included in the second transmission, the first reference signal is included in the third transmission, and the first reference signal is not included in the fourth transmission. Of course, the total number of repeated transmissions and the transmission interval are not limited to the above example.

[0181] As the setting information, for example, a predetermined threshold value related to the number of repeated transmissions may be notified. In addition, as the setting information, for example, an interval of the number of repeated transmissions at which the first reference signal should be transmitted (for example, every two times in the above example) may be notified. Note that the predetermined threshold value related to the number of repeated transmissions and the interval of the number of repeated transmissions at which the first reference signal should be transmitted may be the same value. For example, when the number of repeated transmissions is N or more, the first reference signal may be transmitted every N times.

[0182] refer to Fig.14 and Fig.15 , illustrating an example of the process of switching processing based on the number of repeated transmissions.

[0183] Fig.14 and Fig.151 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as a communication control device 300. In addition, the base station 10 and the terminal device 20 function as a first communication device 100 and a second communication device 200, respectively. In this sequence, for example, it is assumed that after the first transmission, the first reference signal is transmitted each time the number of repeated transmissions N=2.

[0184] like Fig.14 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S400). Thereafter, the base station 10 and the terminal device 20 perform an initial access procedure (step S402). Thereafter, the base station 10 notifies the terminal device 20 of setting information including settings related to the number of repeated transmissions N (step S404). Thereafter, when a packet is generated in the base station 10 (step S406), the base station 10 notifies the terminal device 20 of the DCI (step S408). Note that the above-mentioned setting information may be included in the DCI and notified. Thereafter, the base station 10 sends a data signal including a reference signal A to the terminal device 20 as the first transmission (first repeated transmission) of the data signal (step S410). Then, the terminal device 20 uses the reference signal A for reception equalization and decodes the data signal (step S412).

[0185] Afterwards, the base station 10 determines whether the reference signal B is included in the second repeated transmission (step S414). This determination is made based on the relationship between the number of repeated transmissions N notified in the setting information and the current number of repeated transmissions. Here, since the transmission is the second repeated transmission, which is the first repeated transmission after the first transmission, it is determined that the reference signal B is not included. Afterwards, the base station 10 notifies the terminal device 20 of the DCI (step S416). Afterwards, the base station 10 sends a data signal that does not include the reference signal B to the terminal device 20 as the second repeated transmission of the data signal (step S418). Afterwards, the terminal device 20 uses the reference signal A received in step S410 to perform transmission equalization (step S420).

[0186] Afterwards, if Fig.15As shown in the diagram, the base station 10 determines whether the reference signal C is included in the third repetition transmission (step S422). Here, since the transmission is the third repetition transmission, which is the second repetition transmission after the first transmission, it is determined that the reference signal C is included. After that, the base station 10 notifies the terminal device 20 of the DCI (step S424). After that, the base station 10 sends a data signal including the reference signal C to the terminal device 20 as the third repetition transmission of the data signal (step S426). After that, the terminal device 20 uses the reference signal C for transmission equalization (step S428).

[0187] After that, the terminal device 20 determines whether to include the reference signal D in the reception response to the data signal (step S430). The determination is made based on whether the elapsed time from receiving the data signal to sending the reception response exceeds a predetermined threshold. Here, it is assumed that the determination does not include the reference signal D. Then, the terminal device 20 performs transmission equalization using the reference signal C (step S432), and transmits the reception response after transmission equalization that does not include the reference signal D (step S434).

[0188] (5) Duplex-based switching

[0189] The first communication device 100 may switch whether to use a predetermined resource to send the first reference signal based on a duplex mode. Here, the duplex mode is a duplex mode in the communication between the first communication device 100 and the second communication device 200.

[0190] For example, when the duplex mode is time division duplex, the first communication device 100 does not send a reference signal in a predetermined resource. This is because in the case of time division duplex, the frequencies used for bidirectional communication are the same, so that the channel information related to the bidirectional communication is the same or similar, thereby making it possible to perform transmission equalization based on the channel information obtained through the second reference signal. On the other hand, when the duplex mode is frequency division duplex, the first communication device 100 sends a reference signal in a predetermined resource. This is because in the case of frequency division duplex, the frequencies used for bidirectional communication are different, so that the channel information related to the bidirectional communication is different, thereby making it difficult to perform transmission equalization based on the channel information obtained through the second reference signal.

[0191] For another example, the first communication device 100 may not send a reference signal in a predetermined resource, regardless of whether the duplexing mode is time division duplexing or frequency division duplexing.

[0192] As the setting information, for example, information indicating a duplex system may be notified.

[0193] refer to Fig.16 and Fig.17 , illustrating an example of switching processing based on the duplex method.

[0194] Fig.16 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the second communication device 200 and the communication control device 300, and the terminal device 20 functions as the first communication device 100.

[0195] like Fig.16 As shown in the diagram, first, the first communication device 100 notifies the terminal device 20 of the setting information including the information showing the duplex mode (step S500). After that, the terminal device 20 sends the capability information to the base station 10 (step S502). After that, the base station 10 and the terminal device 20 perform the initial access process (step S504). Then, when a packet is generated in the base station 10 (step S506), the base station 10 notifies the terminal device 20 of the DCI (step S508). After that, the base station 10 sends the data signal including the reference signal A to the terminal device 20 (step S510). Then, the terminal device 20 uses the reference signal A for reception equalization and decodes the data signal (step S512).

[0196] Afterwards, the terminal device 20 determines whether to include the reference signal B in the reception response to the data signal (step S514). The determination is made based on the duplex mode notified in the setting information. When it is determined that the reference signal B is not included (step S514 / No), the terminal device 20 uses the reference signal A for transmission equalization (step S516) and sends a reception response after transmission equalization that does not include the reference signal B (step S518). On the other hand, when it is determined that the reference signal B is included (step S514 / Yes), the terminal device 20 sends a reception response including the reference signal B (step S520). Subsequently, the base station 10 uses the reference signal B for reception equalization and decodes the reception response (step S522).

[0197] Fig.17 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the first communication device 100 and the communication control device 300, and the terminal device 20 functions as the second communication device 200.

[0198] like Fig.17As shown in the diagram, first, the first communication device 100 notifies the terminal device 20 of the setting information including the information showing the duplex mode (step S530). After that, the terminal device 20 sends the capability information to the base station 10 (step S532). After that, the base station 10 and the terminal device 20 perform the initial access process (step S534). Then, when a packet is generated in the terminal device 20 (step S536), the terminal device 20 notifies the base station 10 of the scheduling request (SR) (step S538). After that, the base station 10 performs scheduling and notifies the terminal device 20 of the DCI (step S540). After that, the terminal device 20 sends a data signal including a reference signal A to the base station 10 (step S542). Then, the base station 10 uses the reference signal A for reception equalization and decodes the data signal (step S544).

[0199] Afterwards, the base station 10 determines whether to include reference signal B in the reception response to the data signal (step S546). The determination is made based on the duplex mode notified in the setting information. When it is determined that reference signal B is not included (step S546 / no), the base station 10 uses reference signal A for transmission equalization (step S548) and sends a reception response after transmission equalization that does not include reference signal B (step S550). On the other hand, when it is determined that reference signal B is included (step S546 / yes), the base station 10 sends a reception response including reference signal B (step S552). Subsequently, the terminal device 20 uses reference signal B for reception equalization and decodes the reception response (step S554).

[0200] Note that in steps S550 and S552, instead of receiving a response (ACK / NACK), a DCI for retransmission may be transmitted.

[0201] (6) Switching based on beam correspondence

[0202] The first communication device 100 may switch whether to use a predetermined resource to send a first reference signal based on whether the beam correspondence is maintained. Here, the beam correspondence relates to the relationship between the transmission beam and the reception beam of the first communication device 100 suitable for communicating with the second communication device 200. When the beam correspondence is maintained, it means that at least one of the case where the transmission beam can be determined based on the reception beam and the case where the reception beam can be determined based on the transmission beam is realized. When the beam correspondence is not maintained, it means that neither of the above two cases is realized.

[0203] For example, when the beam correspondence is maintained, the first communication device 100 does not use the predetermined resources to send the first reference signal. This is because when the beam correspondence is maintained, it is assumed that the channel information related to the bidirectional communication is the same or similar, so that transmission equalization based on the channel information obtained through the second reference signal becomes possible. On the other hand, when the beam correspondence is not maintained, the first communication device 100 sends the first reference signal using the predetermined resources.

[0204] As the setting information, for example, information about beam correspondence may be notified. Examples of the information about beam correspondence include location information of the second communication device 200, information showing the mobility of the second communication device 200, and information showing that the first communication device 100 or the second communication device 200 currently maintains beam correspondence.

[0205] refer to Fig.18 and Fig.19 , illustrating an example of the process of switching processing based on beam correspondence.

[0206] Fig.18 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the second communication device 200 and the communication control device 300, and the terminal device 20 functions as the first communication device 100.

[0207] like Fig.18 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S600). Afterwards, the base station 10 and the terminal device 20 perform an initial access process (step S602). Afterwards, the base station 10 notifies the terminal device 20 of setting information including information corresponding to the beam (step S604). Then, when a packet is generated in the base station 10 (step S606), the base station 10 notifies the terminal device 20 of the DCI (step S608). Note that the above-mentioned setting information may be included in the DCI and notified. Afterwards, the base station 10 sends a data signal including a reference signal A to the terminal device 20 (step S610). Then, the terminal device 20 uses the reference signal A for reception equalization and decodes the data signal (step S612).

[0208] Afterwards, the terminal device 20 determines whether to include the reference signal B in the reception response to the data signal (step S614). The determination is made based on whether the beam correspondence is maintained. When it is determined that the reference signal B is not included (step S614 / No), the terminal device 20 uses the reference signal A for transmission equalization (step S616) and sends a reception response after transmission equalization that does not include the reference signal B (step S618). On the other hand, when it is determined that the reference signal B is included (step S614 / Yes), the terminal device 20 sends a reception response including the reference signal B (step S620). Subsequently, the base station 10 uses the reference signal B for reception equalization and decodes the reception response (step S622).

[0209] Fig.19 1 is a sequence diagram illustrating an example of the flow of a switching process of transmission / non-transmission of a first reference signal performed in the communication system 1 according to the present embodiment. In this sequence, a base station 10 and a terminal device 20 are involved. In this sequence, the base station 10 functions as the first communication device 100 and the communication control device 300, and the terminal device 20 functions as the second communication device 200.

[0210] like Fig.19 As shown in the diagram, first, the terminal device 20 sends capability information to the base station 10 (step S630). After that, the base station 10 and the terminal device 20 perform an initial access process (step S632). After that, the base station 10 notifies the terminal device 20 of setting information including information about beam correspondence, or the terminal device 20 notifies the base station device 10 of information showing that the beam correspondence is currently maintained (step S634). Then, when a packet is generated in the terminal device 20 (step S636), the terminal device 20 notifies the base station 10 of a scheduling request (SR) (step S638). After that, the base station 10 performs scheduling and notifies the terminal device 20 of DCI (step S640). After that, the terminal device 20 sends a data signal including a reference signal A to the base station 10 (step S642). Then, the base station 10 performs reception equalization using the reference signal A and decodes the data signal (step S644).

[0211] Afterwards, the base station 10 determines whether to include reference signal B in the reception response to the data signal (step S646). The determination is made based on whether the beam correspondence is maintained. When it is determined that reference signal B is not included (step S646 / no), the base station 10 uses reference signal A for transmission equalization (step S648) and sends a reception response after transmission equalization that does not include reference signal B (step S650). On the other hand, when it is determined that reference signal B is included (step S646 / yes), the base station 10 sends a reception response including reference signal B (step S652). Subsequently, the terminal device 20 uses reference signal B for reception equalization and decodes the reception response (step S654).

[0212] Note that in steps S650 and S652, instead of receiving a response (ACK / NACK), a DCI for retransmission may be transmitted.

[0213] <<4. Application Examples>>

[0214] The technology disclosed herein can be applied to various products. For example, the communication control device 300 can be implemented as any type of server, such as a tower server, a rack server, or a blade server. In addition, the communication control device 300 can be a control module installed on the server (for example, an integrated circuit module formed by a small chip, or a card or blade inserted into a slot of a blade server).

[0215] In addition, for example, each of the first communication device 100, the second communication device 200, and the communication control device 300 can be implemented as any type of evolved Node B (eNB), such as a macro eNB or a small eNB. A small eNB can be an eNB that covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB, or a home (fly) eNB. Each of the first communication device 100, the second communication device 200, and the communication control device 300 can be implemented as other types of base stations, such as a Node B or a base transceiver station (BTS). Each of the first communication device 100, the second communication device 200, and the communication control device 300 can include a main body (also referred to as a base station device) that controls wireless communication, and one or more remote radio heads (RRHs) placed in a place different from the main body. In addition, the various types of terminals described below can play the role of the first communication device 100, the second communication device 200, and the communication control device 300 by temporarily or semi-permanently performing the base station function.

[0216] In addition, for example, each of the first communication device 100, the second communication device 200, and the communication control device 300 can be implemented as a smart phone, a tablet personal computer (PC), a notebook PC, a portable game terminal, a mobile terminal such as a portable / adapter-type mobile router or a digital camera, or a vehicle-mounted terminal, such as a vehicle-mounted navigation device. In addition, each of the first communication device 100, the second communication device 200, and the communication control device 300 can be implemented as a terminal for machine-to-machine (M2M) communication (also referred to as a machine type communication (MTC) terminal). In addition, each of the first communication device 100, the second communication device 200, and the communication control device 300 can be a wireless communication module (for example, an integrated circuit module formed by a small chip) installed on the terminal.

[0217] <4.1. Application examples related to communication control equipment>

[0218] Fig. 20 700 is a block diagram illustrating an example of a schematic configuration of a server 700 to which the technology of the present disclosure can be applied. The server 700 includes a processor 701 , a memory 702 , a storage device 703 , a network interface 704 , and a bus 706 .

[0219] The processor 701 may be, for example, a central processing unit (CPU) or a digital signal processor (DSP), and controls various functions of the server 700. The memory 702 includes a random access memory (RAM) and a read-only memory (ROM), and stores programs and data executed by the processor 701. The storage device 703 may include a storage medium such as a semiconductor memory or a hard disk.

[0220] The network interface 704 is a wired communication interface for connecting the server 700 to a wired communication network 705. The wired communication network 705 may be a core network such as an evolved packet core (EPS), or a packet data network (PDN) such as the Internet.

[0221] The bus 706 interconnects the processor 701, the memory 720, the storage device 703, and the network interface 704. The bus 706 may include two or more buses of different speeds (eg, a high-speed bus and a low-speed bus).

[0222] exist Fig. 20 The server 700 shown in the diagram includes a reference Figure 6One or more components (e.g., notification unit 331) in the control unit 330 described above may be installed in the processor 701. For example, a program for causing the processor to play one or more roles of the above components (in other words, a program for causing the processor to perform one or more operations of the above components) may be installed in the server 700, and the processor 701 may execute the program. For another example, the server 700 may be equipped with a module including a processor 701 and a memory 702, and one or more of the above components may be installed in the module. In this case, the module may store the program for causing the processor to play one or more roles of the above components in the memory 702, and the program may be executed by the processor 701. As described above, the server 700 or the above module may be provided as a device including one or more of the above components, and a program for causing the processor to play one or more roles of the above components may be provided. In addition, a readable recording medium having the above program recorded thereon may be provided.

[0223] In addition, Fig. 20 In the server 700 shown in the diagram, for example, reference Figure 6 The described communication unit 310 may be installed in the network interface 704. In addition, the storage unit 320 may be installed in the memory 702 and / or the storage device 703.

[0224] <4.2. Application examples related to base stations>

[0225] (First Application Example)

[0226] Fig.21 8 is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology of 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.

[0227] Each antenna 810 has one or more antenna elements (e.g., multiple antenna elements forming a MIMO antenna) and is used for transmission and reception of radio signals by the base station device 820. The eNB 800 has multiple antennas 810, such as Fig.21 As shown in the diagram, for example, the multiple antennas 810 may correspond to multiple frequency bands used by the eNB 800. Fig.21 The illustration illustrates an example in which the eNB 800 has multiple antennas 810 , although the eNB 800 may have a single antenna 810 .

[0228] The base station device 820 includes a controller 821 , a memory 822 , a network interface 823 , and a wireless communication interface 825 .

[0229] The controller 821 may be, for example, a CPU or a DSP, and runs various functions of the upper layers of the base station device 820. For example, the controller 821 generates data packets according to the data in the signal processed by the wireless communication interface 825, and transmits the generated packets via the network interface 823. The controller 821 may generate packetized packets by packetizing data from a plurality of baseband processors, and transmit the generated packetized packets. In addition, the controller 821 may have a logical function of performing controls such as radio resource control, radio bearer control, mobility management, admission control, or scheduling. In addition, the control may be performed in coordination with surrounding eNBs or core network nodes. The memory 822 includes a RAM and a ROM, and stores programs executed by the controller 821, as well as various control data (e.g., a terminal list, transmission power data, and scheduling data).

[0230] The network interface 823 is a communication interface for connecting the base station device 820 and the core network 824. The controller 821 can communicate with the core network node or other eNBs via the network interface 823. In this case, the eNB 800 and the core network node or other eNBs can be connected to each other through a logical interface (e.g., an S1 interface or an X2 interface). The network interface 823 can be a wired communication interface, or a wireless communication interface for wireless backhaul. When the network interface 823 is a wireless communication interface, the network interface 823 can use a higher frequency band than the frequency band used by the wireless communication interface 825 for wireless communication.

[0231] The wireless communication interface 825 supports a cellular communication method such as Long Term Evolution (LTE) or LTE-Advanced, and provides a wireless connection with a terminal located in a cell of the eNB 800 via the antenna 810. The wireless communication interface 825 may generally include a baseband (BB) processor 826 and an RF circuit 827. The BB processor 826 may, for example, perform encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and perform various signal processing of each layer (e.g., L1, media access control (MAC), radio link control (RLC), and packet data convergence protocol (PDCP)). The BB processor 826 may replace the controller 821 and have some or all of the above-mentioned logical functions. 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-mentioned program. In addition, the above-mentioned module may be a card or a blade inserted into a slot of the base station device 820, or may be a chip mounted on the above-mentioned card or blade. On the other hand, the RF circuit 827 may include a mixer, a filter, and an amplifier, and transmit and receive a radio signal via the antenna 810 .

[0232] The wireless communication interface 825 may include multiple BB processors 826, such as Fig.21 As shown in the diagram, and for example, the multiple BB processors 826 may correspond to multiple frequency bands used by the eNB 800. In addition, the wireless communication interface 825 includes multiple RF circuits 827, such as Fig.21 As shown in the diagram, and for example, the plurality of RF circuits 827 may correspond to a plurality of antenna elements. Fig.21 The illustration illustrates an example in which the wireless communication interface 825 includes a plurality of BB processors 826 and a plurality of RF circuits 827 , however, the wireless communication interface 825 may include a single BB processor 826 or a single RF circuit 827 .

[0233] exist Fig.21 In the eNB 800 shown in the diagram, the Figure 4 The control unit 140 described or referenced Figure 5 The control unit 240 described and referenced Figure 6 One or more components (notification unit 141 and communication control unit 143 or communication control unit 241 and / or notification unit 331) in the control unit 330 described above may be installed in the wireless communication interface 825. Alternatively, at least some of these components may be installed in the controller 821. For example, the eNB 800 may be equipped with a module including a part (e.g., BB processor 826) or all of the wireless communication interface 825 and / or the controller 821, and one or more of the above components may be installed in the module. In this case, the above module may store a program for causing the processor to function as one or more of the above components (in other words, a program for causing the processor to perform one or more operations of the above components), and the program may be executed. For another example, a program for causing the processor to function as one or more of the above components may be installed in the eNB 800, and the wireless communication interface 825 (e.g., BB processor 826) and / or the controller 821 may execute the program. As described above, the eNB 800, the base station device 820, or the above module may be provided as a device including one or more of the above components, and a program for causing the processor to function as one or more of the above components may be provided. Furthermore, a readable recording medium having the above-mentioned program recorded thereon can be provided.

[0234] In addition, Fig.21 In the eNB 800 shown in the diagram, reference Figure 4 The wireless communication unit 120 described or referenced Figure 5 The wireless communication unit 220 described in reference Figure 6The described communication unit 310 may be installed in the wireless communication interface 825 (eg, the RF circuit 827). In addition, the antenna unit 110 or the antenna unit 210 may be installed on the antenna 810. In addition, the storage unit 130 or the storage unit 230 and the storage unit 320 may be installed in the memory 822.

[0235] (Second application example)

[0236] Fig. 22 8 is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology of the present disclosure can be applied. The eNB 830 includes one or more antennas 840, a base station device 850, and an RRH 860. Each antenna 840 and the RRH 860 can be connected to each other via an RF cable. In addition, the base station device 850 and the RRH 860 can be connected to each other via a high-speed line such as an optical cable.

[0237] Each antenna 840 has one or more antenna elements (e.g., multiple antenna elements forming a MIMO antenna) and is used for transmission and reception of radio signals by the RRH 860. The eNB 830 has multiple antennas 840, such as Fig. 22 As shown in , and for example, the multiple antennas 840 may correspond to the multiple frequency bands used by the eNB 830. Fig. 22 The illustration illustrates an example in which the eNB 830 has multiple antennas 840 , although the eNB 830 may have a single antenna 840 .

[0238] The base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857. The controller 851, the memory 852, and the network interface 853 are similar to those of the reference Fig.21 The controller 821, memory 822 and network interface 823 are illustrated.

[0239] The wireless communication interface 855 supports a cellular communication method such as LTE or LTE-Advanced, and provides a wireless connection with a terminal located in a sector corresponding to the RRH 860 via the RRH 860 and the antenna 840. The wireless communication interface 855 may generally include a BB processor 856, etc. The BB processor 856 is similar to the reference 8 except that the BB processor 856 is connected to the RF circuit 864 of the RRH 860 via the connection interface 857. Fig.21 The wireless communication interface 855 includes a plurality of BB processors 856, such as Fig. 22 As shown in the diagram, for example, the multiple BB processors 856 may correspond to multiple frequency bands used by the eNB 830. Fig. 22The illustration illustrates an example in which the wireless communication interface 855 includes a plurality of BB processors 856 ; however, the wireless communication interface 855 may include a single BB processor 856 .

[0240] The connection interface 857 is an interface for connecting the base station device 850 (wireless communication interface 855) and the RRH 860. The connection interface 857 may be a communication module for connecting the base station device 850 (wireless communication interface 855) and the RRH 860 for communication on a high-speed line.

[0241] The RRH 860 also includes a connection interface 861 and a wireless communication interface 863 .

[0242] The connection interface 861 is an interface for connecting the RRH 860 (wireless communication interface 863) and the base station device 850. The connection interface 861 may be a communication module for communication on a high-speed line.

[0243] The wireless communication interface 863 sends and receives radio signals via the antenna 840. The wireless communication interface 863 may generally include an RF circuit 864, etc. The RF circuit 864 may include a mixer, a filter, and an amplifier, and sends and receives radio signals via the antenna 840. The wireless communication interface 863 includes a plurality of RF circuits 864, such as Fig. 22 As shown in the diagram, and for example, the multiple RF circuits 864 may correspond to multiple antenna elements. Fig. 22 The illustration illustrates an example in which the wireless communication interface 863 includes a plurality of RF circuits 864 ; however, the wireless communication interface 863 may include a single RF circuit 864 .

[0244] exist Fig. 22 In the eNB 830 shown in the diagram, the reference Figure 4 The control unit 140 described or referenced Figure 5 The control unit 240 described and referenced Figure 6One or more components (notification unit 141 and communication control unit 143 or communication control unit 241 and / or notification unit 331) in the control unit 330 described above may be installed in the wireless communication interface 855 and / or the wireless communication interface 863. Alternatively, at least some of these components may be installed in the controller 851. For example, the eNB 830 may be equipped with a module including a part (e.g., BB processor 856) or all of the wireless communication interface 855 and / or the controller 851, and one or more of the above components may be installed in the module. In this case, the above module may store a program for causing the processor to function as one or more of the above components (in other words, a program for causing the processor to perform one or more operations of the above components), and the program may be executed. For another example, a program for causing the processor to function as one or more of the above components may be installed in the eNB 830, and the wireless communication interface 855 (e.g., BB processor 856) and / or the controller 851 may execute the program. As described above, the eNB 830, the base station device 850 or the above modules may be provided as a device including one or more of the above components, and a program for causing a processor to function as one or more of the above components may be provided. In addition, a readable recording medium having the above program recorded thereon may be provided.

[0245] In addition, Fig. 22 In the eNB 830 shown in the diagram, for example, reference Figure 4 The wireless communication unit 120 described or referenced Figure 5 The wireless communication unit 220 described in reference Figure 6 The described communication unit 310 may be installed in the wireless communication interface 863 (eg, the RF circuit 864). In addition, the antenna unit 110 or the antenna unit 210 may be installed on the antenna 840. In addition, the storage unit 130 or the storage unit 230 and the storage unit 320 may be installed in the memory 852.

[0246] <4.3. Application examples related to terminal equipment>

[0247] (First Application Example)

[0248] Fig.23 9 is a block diagram illustrating an example of a schematic configuration of a smartphone 900 to which the technology of the present disclosure can be applied. The smartphone 900 includes a processor 901, a memory 902, a storage device 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 912, one or more antenna switches 915, one or more antennas 916, a bus 917, a battery 918, and an auxiliary controller 919.

[0249] The processor 901 may be, for example, a CPU or a system on chip (SoC), and controls the functions of the application layer and other layers of the smartphone 900. The memory 902 includes a RAM and a ROM, and stores programs executed by the processor 901 and data. The storage device 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 universal serial bus (USB) device to the smartphone 900.

[0250] The camera 906 has an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and generates an imaging 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 smart phone 900 into a voice signal. The input device 909 includes, for example, a touch sensor, a keypad, a keyboard, a button, or a switch that detects a touch on the screen of the display device 910, and receives an operation or information input from a user. The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays an output image of the smart phone 900. The speaker 911 converts the voice signal output from the smart phone 900 into a voice.

[0251] The wireless communication interface 912 supports cellular communication modes such as LTE or LTE-Advanced, and performs wireless communication. The wireless communication interface 912 may generally include a BB processor 913 and an RF circuit 914. The BB processor 913 may, for example, perform encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and perform various signal processing for wireless communication. On the other hand, the RF circuit 914 may include a mixer, a filter, and an amplifier, and transmit and receive radio signals via an antenna 916. The wireless communication interface 912 may be a single-chip module in which the BB processor 913 and the RF circuit 914 are integrated. The wireless communication interface 912 may include a plurality of BB processors 913 and a plurality of RF circuits 914, such as Fig.23 As shown in the figure. Fig.23 The illustration illustrates an example in which the wireless communication interface 912 includes a plurality of BB processors 913 and a plurality of RF circuits 914 , however, the wireless communication interface 912 may include a single BB processor 913 or a single RF circuit 914 .

[0252] In addition, in addition to the cellular communication mode, the wireless communication interface 912 can also support other types of wireless communication modes, such as short-range wireless communication mode, near field communication mode or wireless local area network (LAN) mode. In this case, the wireless communication interface 912 can include a BB processor 913 and an RF circuit 914 for each wireless communication mode.

[0253] Each antenna switch 915 switches the connection destination of the antenna 916 between a plurality of circuits (for example, circuits for different wireless communication methods) included in the wireless communication interface 912 .

[0254] Each antenna 916 has one or more antenna elements (e.g., multiple antenna elements forming a MIMO antenna) and is used for transmission and reception of radio signals by the wireless communication interface 912. The smartphone 900 may include multiple antennas 916, such as Fig.23 As shown in the figure. Fig.23 The illustration illustrates an example in which the smartphone 900 has a plurality of antennas 916 , however, the smartphone 900 may have a single antenna 916 .

[0255] Furthermore, the smartphone 900 may include an antenna 916 for each wireless communication method. In this case, the antenna switch 915 may be omitted from the configuration of the smartphone 900 .

[0256] The bus 917 interconnects the processor 901, the memory 902, the storage device 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. The battery 918 supplies power to the power supply circuit 918 through the dashed line in the figure. Fig.23 The auxiliary controller 919 supplies power to the various components of the smartphone 900 illustrated in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900, for example, in a sleep mode.

[0257] exist Fig.23 In the smart phone 900 shown in the diagram, the reference Figure 4 The control unit 140 described or referenced Figure 5 The control unit 240 described and referenced Figure 6One or more components (notification unit 141 and communication control unit 143 or communication control unit 241 and / or notification unit 331) in the control unit 330 described above may be installed in the wireless communication interface 912. Alternatively, at least some of these components may be installed in the processor 901 or the auxiliary controller 919. For example, the smart phone 900 may be equipped with a module including a part (e.g., BB processor 913) or all of the wireless communication interface 912, the processor 901 and / or the auxiliary controller 919, and one or more of the above components may be installed in the module. In this case, the above module may store a program for causing the processor to function as one or more of the above components (in other words, a program for causing the processor to perform one or more operations of the above components), and the program may be executed. For another example, a program for causing the processor to function as one or more of the above components may be installed in the smart phone 900, and the wireless communication interface 912 (e.g., BB processor 913), the processor 901 and / or the 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 of the above components, and a program for causing a processor to function as one or more of the above components may be provided. In addition, a readable recording medium having the above program recorded thereon may be provided.

[0258] In addition, Fig.23 In the smart phone 900 shown in the diagram, for example, referring to Figure 4 The wireless communication unit 120 described or referenced Figure 5 The wireless communication unit 220 described in reference Figure 6 The communication unit 310 described may be installed in the wireless communication interface 912 (eg, the RF circuit 914). In addition, the antenna unit 110 or the antenna unit 210 may be installed on the antenna 916. In addition, the storage unit 130 or the storage unit 230 and the storage unit 320 may be installed in the memory 902.

[0259] (Second application example)

[0260] Fig.24 9 is a block diagram illustrating an example of a schematic configuration of an in-vehicle navigation device 920 to which the technology of the present disclosure can be applied. The in-vehicle 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.

[0261] The processor 921 may be, for example, a CPU or an SoC, and controls navigation functions and other functions of the in-vehicle navigation device 920. The memory 922 includes a RAM and a ROM, and stores programs executed by the processor 921 and data.

[0262] The GPS module 924 measures the position (e.g., latitude, longitude, and altitude) of the vehicle-mounted navigation device 920 using GPS signals received from GPS satellites. The sensor 925 may include, for example, a group of sensors such as a gyro sensor, a geomagnetic sensor, and an air 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.

[0263] The content player 927 plays the content stored in the storage medium (e.g., CD or DVD) inserted in the storage medium interface 928. The input device 929 includes, for example, a touch sensor, a button, or a switch that detects a touch on the screen of the display device 930, and receives an operation or information input from a user. The display device 930 has a screen such as an LCD or OLED display, and displays an image of a navigation function or a content that is played. The speaker 931 outputs the voice of the navigation function or the content that is played.

[0264] The wireless communication interface 933 supports cellular communication methods such as LTE or LTE-Advanced, and performs wireless communication. The wireless communication interface 933 may generally include a BB processor 934 and an RF circuit 935. The BB processor 934 may, for example, perform encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and perform various signal processing for wireless communication. On the other hand, the RF circuit 935 may include a mixer, a filter, and an amplifier, and transmit and receive radio signals via an antenna 937. The wireless communication interface 933 may be a single-chip module in which the BB processor 934 and the RF circuit 935 are integrated. The wireless communication interface 933 may include a plurality of BB processors 934 and a plurality of RF circuits 935, such as Fig.24 As shown in the diagram. Fig.24 The illustration illustrates an example in which the wireless communication interface 933 includes a plurality of BB processors 934 and a plurality of RF circuits 935 , however, the wireless communication interface 933 may include a single BB processor 934 or a single RF circuit 935 .

[0265] In addition, in addition to the cellular communication mode, the wireless communication interface 933 can also support other types of wireless communication modes, such as short-range wireless communication mode, near field communication mode or wireless LAN mode. In this case, the wireless communication interface 933 can include a BB processor 934 and an RF circuit 935 for each wireless communication mode.

[0266] Each antenna switch 936 switches the connection destination of the antenna 937 between a plurality of circuits (for example, circuits for different wireless communication methods) included in the wireless communication interface 933 .

[0267] Each antenna 937 has one or more antenna elements (for example, multiple antenna elements forming a MIMO antenna) and is used for transmission and reception of radio signals by the wireless communication interface 933. The in-vehicle navigation device 920 may have multiple antennas 937, such as Fig.24 Although Fig.24 The illustration illustrates an example in which the in-vehicle navigation device 920 has a plurality of antennas 937 , however, the in-vehicle navigation device 920 may have a single antenna 937 .

[0268] Furthermore, the in-vehicle navigation device 920 may include an antenna 937 for each wireless communication method. In this case, the antenna switch 936 may be omitted from the configuration of the in-vehicle navigation device 920.

[0269] The battery 938 supplies power to the Fig.24 The respective components of the in-vehicle navigation device 920 illustrated in the figure are powered. In addition, the battery 938 stores power supplied from the vehicle side.

[0270] exist Fig.24 In the vehicle navigation device 920 shown in the diagram, the reference Figure 4 The control unit 140 described or referenced Figure 5 The control unit 240 described and referenced Figure 6One or more components (notification unit 141 and communication control unit 143 or communication control unit 241 and / or notification unit 331) in the control unit 330 described above may be installed in the wireless communication interface 933. Alternatively, at least some of these components may be installed in the processor 921. For example, the vehicle navigation device 920 may be equipped with a module including a part (e.g., BB processor 934) or all of the wireless communication interface 933 and / or the processor 921, and one or more of the above components may be installed in the module. In this case, the above module may store a program for causing the processor to play one or more roles of the above components (in other words, a program for causing the processor to perform one or more operations of the above components), and the program may be executed. For another example, a program for causing the processor to play one or more roles of the above components may be installed in the vehicle navigation device 920, and the wireless communication interface 933 (e.g., BB processor 934) and / or the processor 921 may execute the program. As described above, the vehicle navigation device 920 or the module may be provided as a device including one or more of the above components, and a program for causing the processor to play one or more roles of the above components may be provided. Furthermore, a readable recording medium having the above-mentioned program recorded thereon can be provided.

[0271] In addition, Fig.24 In the vehicle-mounted navigation device 920 shown in the diagram, for example, reference Figure 4 The wireless communication unit 120 described or referenced Figure 5 The wireless communication unit 220 described in reference Figure 6 The communication unit 310 described may be installed in the wireless communication interface 933 (eg, the RF circuit 935). In addition, the antenna unit 110 or the antenna unit 210 may be installed on the antenna 937. In addition, the storage unit 130 or the storage unit 230 and the storage unit 320 may be installed in the memory 922.

[0272] In addition, the technology according to the present disclosure may be implemented as an in-vehicle system (or vehicle) 940 including one or more components of the in-vehicle navigation device 920, 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 fault information, and outputs the generated data to the in-vehicle network 941.

[0273] <<5. Conclusion>>

[0274] As mentioned above, reference Figure 1-Figure 24An embodiment of the present disclosure is described in detail. As described above, the first communication device 100 according to the present embodiment switches whether to use a predetermined resource predetermined for sending a first reference signal to send a first reference signal. For example, when transmission equalization or reception equalization based on pre-acquired channel information is possible, the first communication device 100 does not send the first reference signal, otherwise the first reference signal is sent. As a result, the transmission of a reference signal that is not always required for decoding a transmission signal is omitted, so that the transmission efficiency of the entire system can be further improved.

[0275] The preferred embodiments of the present disclosure are described in detail above with reference to the accompanying drawings, but the technical scope of the present disclosure is not limited to such examples. Obviously, a person skilled in the art of the present disclosure can think of various changes or modifications within the scope of the technical ideas recorded in the appended claims, and it should be understood that such changes or modifications naturally also belong to the technical scope of the present disclosure.

[0276] For example, in the above embodiment, Figure 7-Figure 19 , the switching process of the reference signal transmitted on the downlink or the sidelink is described, but the present technology is not limited to such an example. The switching process described for the reference signal transmitted on the downlink can be similarly applied to the switching of the reference signal transmitted on the uplink or the sidelink. In addition, the switching process described for the reference signal transmitted on the uplink can be similarly applied to the switching of the reference signal transmitted on the downlink or the sidelink.

[0277] In addition, the processing described in this specification by using flowcharts and sequence diagrams does not necessarily have to be performed in the order shown in the diagrams. Some processing steps can be performed in parallel. In addition, additional processing steps can be adopted, and some processing steps can be omitted.

[0278] In addition, the effects recorded in this specification are merely illustrative or exemplary, and not restrictive. That is, in addition to or in place of the above effects, the technology according to the present disclosure can exhibit other effects that are obvious to those skilled in the art based on the description of this specification.

[0279] Note that the following configurations also belong to the technical scope of the present disclosure.

[0280] (1) A communication device comprising:

[0281] A control unit is configured to switch whether to use a predetermined resource predetermined for sending a reference signal to send the first reference signal.

[0282] (2) The communication device according to (1), wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on pre-acquired channel information.

[0283] (3) The communication device according to (2), wherein the control unit switches whether to transmit the first reference signal using the predetermined resource based on an elapsed time since the second reference signal was received from the communication partner.

[0284] (4) The communication device according to (3), wherein the control unit switches whether to include the first reference signal in the reception response based on an elapsed time until a reception response including the second reference signal is transmitted.

[0285] (5) The communication device according to any one of (2) to (4), wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on the number of symbols included in the time slot.

[0286] (6) The communication device according to any one of (2) to (5), wherein the control unit switches whether to use the predetermined resource to send the first reference signal based on whether a predetermined timer has expired or within a predetermined time interval.

[0287] (7) The communication device according to any one of (2) to (6), wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on the number of repeated transmissions.

[0288] (8) The communication device according to any one of (2) to (7), wherein the control unit switches whether to use the predetermined resource to send the first reference signal based on a duplex mode.

[0289] (9) The communication device according to any one of (2) to (8), wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on whether the beam correspondence is maintained.

[0290] (10) The communication device according to any one of (2) to (9), wherein when the predetermined resource is not used to transmit the first reference signal, the control unit performs transmission equalization based on the channel information.

[0291] (11) A communication device according to any one of (1) to (10), wherein the control unit switches whether to use the reserved resources to send the first reference signal based on at least one of information indicating whether to use the reserved resources to send the first reference signal, information showing the type of channel indicated not to be used for sending the first reference signal, and identification information of the reserved resources indicated not to be used for sending the first reference signal.

[0292] (12) The communication device according to any one of (1) to (10), wherein the control unit switches whether to use the predetermined resource to send the first reference signal based on information indicating a reference for switching whether to use the predetermined resource to send the first reference signal.

[0293] (13) The communication device according to any one of (1) to (12), wherein the control unit transmits capability information regarding switching whether to use the predetermined resource to transmit the first reference signal.

[0294] (14) The communication device according to any one of (1) to (13), wherein

[0295] The first reference signal using the predetermined resource is not transmitted in the communication in the first direction, and the second reference signal using the predetermined resource is transmitted in the communication in the second direction opposite to the first direction, and

[0296] The first direction and the second direction are downlink and uplink, uplink and downlink, or sidelink and sidelink, respectively.

[0297] (15) The communication device according to any one of (1) to (14), wherein

[0298] not transmitting a first reference signal using a predetermined resource within resources for a first purpose, but transmitting a second reference signal using a predetermined resource within resources for a second purpose different from the first purpose, and

[0299] The resource for the first purpose and the resource for the second purpose are respectively a control resource and a data resource, or a data resource and a control resource.

[0300] (16) A communication device comprising:

[0301] A control unit is configured to perform reception processing corresponding to whether the first reference signal is sent using a predetermined resource predetermined for sending the reference signal.

[0302] (17) A communication method, comprising:

[0303] Using the processor, switching whether to send the first reference signal using a predetermined resource predetermined for sending the reference signal.

[0304] (18) A communication method, comprising:

[0305] A reception process is performed using a processor according to whether the first reference signal is transmitted using a predetermined resource predetermined for transmitting the reference signal.

[0306] (19) A recording medium having recorded thereon a program causing a computer to function as a control unit that switches whether to transmit a first reference signal using a predetermined resource that is predetermined for transmitting a reference signal.

[0307] (20) A recording medium having a program recorded thereon, the program causing a computer to function as a control unit that performs reception processing according to whether a first reference signal is transmitted using a predetermined resource predetermined for transmitting a reference signal.

[0308] Reference numerals list

[0309] 1 Communication system

[0310] 10 Base Station

[0311] 20 Terminal Equipment

[0312] 30 Core Network

[0313] 40 PDN

[0314] 100 First Communication Equipment

[0315] 110 antenna units

[0316] 120 Wireless Communication Unit

[0317] 130 storage units

[0318] 140 Control Unit

[0319] 141 Notification Unit

[0320] 143 Communication control unit

[0321] 200 Second communication device

[0322] 210 antenna units

[0323] 220 Wireless Communication Unit

[0324] 230 storage units

[0325] 240 Control Unit

[0326] 241 Communication control unit

[0327] 300 Communication control equipment

[0328] 310 Communication Unit

[0329] 320 storage units

[0330] 330 Control Unit

[0331] 331 Notification Unit

Claims

1. A communication device, comprising: a control unit, the control unit switching whether to use a predetermined resource predetermined for sending a reference signal to send the first reference signal, The control unit switches whether to use the predetermined resource to send the first reference signal based on the pre-acquired channel information; as well as The control unit switches whether to include the first reference signal in the reception response based on an elapsed time until a reception response of a signal including the second reference signal is transmitted. 2 . The communication device according to claim 1 , wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on an elapsed time since the second reference signal was received from the communication counterpart.

3. The communication device according to claim 1, wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on the number of symbols included in the time slot. 4 . The communication device according to claim 1 , wherein the control unit switches whether to use the predetermined resource to send the first reference signal based on whether a predetermined timer has expired or is within a predetermined time interval. 5 . The communication device according to claim 1 , wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on the number of repeated transmissions. 6 . The communication device according to claim 1 , wherein the control unit switches whether to use the predetermined resource to send the first reference signal based on a duplex mode. 7 . The communication device according to claim 1 , wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on whether the beam correspondence is maintained.

8. The communication device according to claim 1, wherein when the predetermined resource is not used to transmit the first reference signal, the control unit performs transmission equalization based on the channel information.

9. A communication device according to claim 1, wherein the control unit switches whether to use the reserved resources to send the first reference signal based on at least one of information indicating whether to use the reserved resources to send the first reference signal, information showing the type of channel indicated not to be used for sending the first reference signal, and identification information of the reserved resources indicated not to be used for sending the first reference signal.

10. The communication device according to claim 1, wherein the control unit switches whether to use the predetermined resource to transmit the first reference signal based on information showing a reference for switching whether to use the predetermined resource to transmit the first reference signal.

11. The communication device according to claim 1, wherein the control unit transmits capability information regarding switching whether to use the predetermined resource to transmit the first reference signal.

12. The communication device according to claim 1, wherein The first reference signal using the predetermined resource is not transmitted in the communication in the first direction, and the second reference signal using the predetermined resource is transmitted in the communication in the second direction opposite to the first direction, and The first direction and the second direction are downlink and uplink, uplink and downlink, or sidelink and sidelink, respectively.

13. The communication device according to claim 1, wherein not transmitting a first reference signal using a predetermined resource within resources for a first purpose, but transmitting a second reference signal using a predetermined resource within resources for a second purpose different from the first purpose, and The resource for the first purpose and the resource for the second purpose are respectively a control resource and a data resource, or a data resource and a control resource.

14. A communication device comprising: a control unit that performs reception processing corresponding to whether a first reference signal is transmitted from a communication partner using a predetermined resource predetermined for transmitting a reference signal, The communication counterpart switches whether to use the predetermined resource to send the first reference signal based on the pre-acquired channel information; as well as The communication partner switches whether to include the first reference signal in the reception response based on an elapsed time until the reception response of the signal including the second reference signal is transmitted.

15. A communication method, comprising: using a processor, switching whether to use a predetermined resource predetermined for sending a reference signal to send a first reference signal, wherein the processor switches whether to use the predetermined resource to send the first reference signal based on the pre-acquired channel information; as well as The processor switches whether to include the first reference signal in the reception response based on an elapsed time until a reception response of a signal including the second reference signal is transmitted.

16. A communication method, comprising: using a processor of the communication device to perform reception processing corresponding to whether a first reference signal is transmitted from a communication partner using a predetermined resource predetermined for transmitting a reference signal, The communication counterpart switches whether to use the predetermined resource to send the first reference signal based on the pre-acquired channel information; as well as The communication partner switches whether to include the first reference signal in the reception response based on an elapsed time until the reception response of the signal including the second reference signal is transmitted.

17. A recording medium having a program recorded thereon, the program causing a computer to function as a control unit, the control unit switching whether to use a predetermined resource predetermined for transmitting a reference signal to transmit a first reference signal, wherein the control unit switches whether to use the predetermined resource to send the first reference signal based on the pre-acquired channel information; and The control unit switches whether to include the first reference signal in the reception response based on an elapsed time until a reception response of a signal including the second reference signal is transmitted.

18. A recording medium having a program recorded thereon, the program causing a computer to function as a control unit of a communication device, the control unit performing reception processing corresponding to whether a first reference signal is transmitted from a communication partner using a predetermined resource predetermined for transmitting a reference signal, wherein the communication counterpart switches whether to use the predetermined resource to send the first reference signal based on pre-acquired channel information; and The communication partner switches whether to include the first reference signal in the reception response based on an elapsed time until the reception response of the signal including the second reference signal is transmitted.

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