Visible light communication device, communication system, and communication method

Abstract

The present invention provides a visible light communication device, communication system, and communication method that can ensure reliable terminal handover when VLC is applied to DL. [Solution] The visible light communication device performs visible light communication using visible light communication signals. The visible light communication device comprises an upstream visible light receiving unit that receives visible light communication signals from an upstream communication device, and a terminal-side visible light transmitting unit that transmits visible light communication signals to a terminal. The terminal-side visible light transmitting unit transmits a visible light communication signal to which identification information identifying the access point of the visible light communication formed by the visible light communication device is multiplexed.

Description

Technical Field

[0001] The present disclosure relates to a visible light communication device, a communication system, and a communication method that support VLC. It relates thereto.

Background Art

[0002] Visible Light Communication (VLC) is a technology that transmits information using visible light. VLC is a form of wireless communication that does not use an optical fiber or the like, and data can be transmitted and received using a lighting device such as an LED light. VLC enables extremely broadband and high-speed (for example, over 100 Gbps) communication even when compared with wireless communication using radio waves (electromagnetic waves in the frequency range of 3 Hz to 3000 GHz).

[0003] Therefore, there has been a search for applying VLC to a mobile communication network, which is a wireless network for performing voice calls and data communication using a mobile device such as a mobile phone or a smartphone (Non-Patent Documents 1 to 3). For example, a configuration combining a downlink (DL) by VLC and an uplink (UL) by infrared communication (IR) is known.

[0004] Since the coverage by a VLC access point (AP) is generally narrower than that of a mobile communication network using radio waves or the like, frequent handovers may be required when executing VLC with a moving terminal such as a mobile device (User Equipment, UE).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] However, in the case of VLC, since the visible light communication signal is typically duplicated and the same visible light communication signal is transmitted from multiple VLC APs, the UE cannot identify the VLC AP from the visible light communication signal received from the VLC AP.

[0007] Therefore, the UE (terminal) cannot provide information about nearby VLC APs to the communication control unit (which may also be called a CCU) that controls the handover, making it difficult to achieve a proper handover.

[0008] Therefore, the following disclosure is made in light of these circumstances and aims to provide a visible light communication device, communication system, and communication method that can ensure reliable terminal handover when VLC is applied to DL. [Means for solving the problem]

[0009] One aspect of the present disclosure is a visible light communication device (VLC unit 100) that performs visible light communication using a visible light communication signal, comprising: an upstream visible light receiving unit (upstream visible light receiving unit 110) that receives the visible light communication signal from an upstream communication control device; and a terminal-side visible light transmitting unit (terminal-side visible light transmitting unit 130) that transmits the visible light communication signal to a terminal, wherein the terminal-side visible light transmitting unit transmits the visible light communication signal on which identification information identifying the access point of the visible light communication formed by the visible light communication device is multiplexed.

[0010] One aspect of the present disclosure is a communication system (communication system 10) including a visible light communication device that performs visible light communication using a visible light communication signal using visible light, and a visible light communication adapter device (VLC adapter 70) that has a connection function to a communication network and performs the visible light communication, wherein the visible light communication device includes an upstream visible light receiving unit that receives the visible light communication signal from an upstream communication device, and a terminal-side visible light transmitting unit that transmits the visible light communication signal to a terminal, the visible light communication adapter device includes a visible light transmitting unit (visible light transmitting unit 73) that transmits the visible light communication signal to the visible light communication device, and a transmission timing control unit (control unit 77) that controls the transmission timing of the visible light communication signal by the terminal-side visible light transmitting unit based on instructions from a communication control device, and the terminal-side visible light transmitting unit transmits the visible light communication signal on which identification information identifying the access point of the visible light communication formed by the visible light communication device is multiplexed. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic diagram of the overall configuration of the communication system 10. [Figure 2] Figure 2 is a functional block diagram of the VLC unit 100. [Figure 3] Figure 3 is a functional block diagram of the VLC adapter 70. [Figure 4] Figure 4 shows an example of the switching operation of a visible light communication signal from a VLC AP (Visible Light Access Panel). [Figure 5] Figure 5 shows an example of the switching operation of the visible light communication signal from the VLC AP (Visible Light Access Panel). [Figure 6] Figure 6 shows an example of the hardware configuration of the VLC adapter 70 and the VLC unit 100. [Modes for carrying out the invention]

[0012] The embodiments will be described below with reference to the drawings. Note that identical or similar reference numerals are used to denote the same functions and components, and their descriptions will be omitted as appropriate.

[0013] (1) Overall outline of the communication system Figure 1 is a schematic diagram of the overall configuration of the communication system 10 according to this embodiment. The communication system 10 utilizes Visible Light Communication (VLC). VLC is a form of wireless communication that does not use optical fibers or the like, and can send and receive data using lighting devices such as LED lights. In particular, the VLC according to this embodiment can achieve a high transmission speed (data rate), and enables extremely wideband and high-speed communication (for example, over 100 Gbps) compared to wireless communication using radio waves (electromagnetic waves with frequencies in the range of 3 Hz to 3000 GHz).

[0014] The visible light used in VLCs generally refers to light with wavelengths ranging from approximately 380 nanometers (nm) to 750 nanometers (nm), which corresponds to the range of light visible to the human eye. Visible light does not need to include ultraviolet or infrared light.

[0015] Wireless communication using radio waves can typically be interpreted as wireless communication that utilizes a mobile communication network, which is a wireless network for voice calls and data communication using mobile devices such as mobile phones and smartphones. The mobile communication network may also be referred to as a mobile communication network, a Public Land Mobile Network (PLMN), etc. The frequency bands used by the mobile communication network include a low frequency band: 600 MHz to 1 GHz, a medium frequency band: 3.5 GHz to 4.7 GHz, a high frequency band (millimeter wave): 24 GHz to 40 GHz band, etc. The mobile communication network may conform to the technical specifications of the 3rd Generation Partnership Project (3GPP: registered trademark) such as 4G (LTE), 5G, or 6G.

[0016] Note that the wireless network using radio waves does not necessarily have to be a mobile communication network. For example, a network conforming to the technical specifications of other wireless communications such as wireless LAN (Wi-Fi (registered trademark)) may be used.

[0017] As shown in FIG. 1, the communication system 10 includes a communication network 20. The communication network 20 may include a part of the above-described mobile communication network, and may further include other wireless networks and wired networks.

[0018] The communication system 10 may include a CCU 30 and a radio base station 50 as entities on the mobile communication network side (which may also be called nodes, etc.). The CCU 30 (Central Control Unit) is one of the control elements of the mobile communication network and may also be called a communication control device. The CCU 30 has a function of controlling the mobile communication network and may be realized by an entity (which may also be a Function) constituting a radio access network (RAN) or a core network (CN).

[0019] The radio base station 50 performs wireless communication using radio waves with the terminal 200 (User Equipment 200, hereinafter referred to as UE 200). The radio base station 50 may be referred to as a gNodeB (gNB), an access point (AP), or the like. Note that the radio base station 50 may be referred to as a radio access point from the perspective of distinguishing it from the VLC unit 100.

[0020] The radio base station 50 may support Massive MIMO (Multiple-Input Multiple-Output) that generates a more directional beam by controlling wireless signals transmitted from a plurality of antenna elements, carrier aggregation (CA) that bundles and uses a plurality of component carriers (CC), and the like.

[0021] A VLC adapter 70 may be connected to the communication network 20. Also, a VLC unit 100 may be connected to the VLC adapter 70. Specifically, the VLC unit 100 may be connected to the downstream side of the VLC adapter 70. Also, another VLC unit 100 may be connected to the downstream side of the VLC unit 100. That is, as shown in FIG. 1, a plurality of VLC units 100 may be connected in a daisy chain.

[0022] The VLC adapter 70 and the VLC unit 100 can function as an access point (AP) for visible light communication. Specifically, the VLC adapter 70 and the VLC unit 100 can transmit a visible light communication signal using visible light toward the UE 200. Thus, the VLC adapter 70 and the VLC unit 100 support visible light communication in the downlink (DL) direction.

[0023] In the present embodiment, the VLC unit 100 may constitute a visible light communication device that performs visible light communication using a visible light communication signal using visible light. Also, the VLC adapter 70 may have a connection function with the communication network and may constitute a visible light communication adapter device that performs visible light communication.

[0024] The communication system 10 may include a terminal 200 (User Equipment 200, hereinafter referred to as UE 200). The UE 200 may also be called user equipment, user device, etc., and is a mobile device that can be moved. The UE 200 may be a portable terminal or an IoT (Internet of Things) device such as an in-vehicle terminal.

[0025] The UE 200 has wireless communication capabilities via a mobile communication network, as well as visible light communication capabilities using VLC. Specifically, the UE 200 can send and receive radio signals using radio waves via a radio base station (not shown) that conforms to the specifications of the mobile communication network. In other words, the UE 200 may support DL and uplink (UL) communication via a mobile communication network.

[0026] Furthermore, the UE 200 can receive visible light communication signals via the VLC unit 100. In other words, the UE 200 can support DL-direction communication via VLC. The UE 200 (and the VLC unit 100) may also support UL-direction VLC communication, but in this embodiment, it is assumed that UL-direction communication will utilize a mobile communication network.

[0027] (2) Functional block configuration of the communication system 10 Next, the functional block configuration of the communication system 10 will be described. Specifically, the functional block configurations of the VLC adapter 70 and the VLC unit 100 will be described. Figure 2 is a functional block configuration diagram of the VLC unit 100. Figure 3 is a functional block configuration diagram of the VLC adapter 70. Note that Figures 2 and 3 only show the main functional blocks related to the description of the embodiment, and the VLC adapter 70 and VLC unit 100 have other functional blocks (for example, a power supply unit). For convenience, the functional block configuration of the VLC unit 100 will be described below.

[0028] (2.1) VLC Unit 100 As shown in Figure 2, the VLC unit 100 includes an upstream visible light receiving unit 110, a downstream visible light transmitting unit 120, a terminal-side visible light transmitting unit 130, and a control unit 140.

[0029] The upstream visible light receiving unit 110 receives visible light communication signals from the upstream communication device. Specifically, the upstream visible light receiving unit 110 may receive visible light communication signals from the VLC adapter 70. If multiple VLC units 100 are connected in a daisy-chain, the upstream visible light receiving unit 110 may receive visible light communication signals from the upstream VLC units 100. Because visible light communication signals have strong directivity, their coverage is usually narrower than that of radio signals (beams) transmitted by radio base stations of mobile communication networks.

[0030] The upstream side may refer to the VLC adapter 70 side or the preceding VLC unit 100 side. The downstream side may refer to the subsequent VLC unit 100 side.

[0031] The downstream visible light transmitter 120 transmits a visible light communication signal to the downstream communication device. Specifically, the downstream visible light transmitter 120 transmits a visible light communication signal to the VLC unit 100 connected downstream. The downstream visible light transmitter 120 may transmit a visible light communication signal to the downstream communication device by relaying the visible light communication signal received by the upstream visible light receiver 110.

[0032] The terminal-side visible light transmitter 130 transmits a visible light communication signal to the UE 200. Specifically, the terminal-side visible light transmitter 130 may transmit a visible light communication signal to the downstream communication device by relaying the visible light communication signal received by the upstream-side visible light receiver 110.

[0033] Furthermore, the coverage (which may be interpreted as directivity) of the visible light communication signal transmitted by the downstream visible light transmitter 120 (hereinafter referred to as VLC 1 as appropriate) may be narrower than the coverage of the visible light communication signal transmitted by the terminal-side visible light transmitter 130 (hereinafter referred to as VLC 2 as appropriate). In other words, it is preferable that the directivity of the visible light communication signal transmitted by the terminal-side visible light transmitter 130 is wider than the directivity of the visible light communication signal transmitted by the downstream visible light transmitter 120. This makes it easier for the UE 200 to be located within the coverage of the visible light communication signal, thereby increasing the possibility of DL reception by VLC.

[0034] On the other hand, since the visible light communication signal transmitted by the downstream visible light transmission unit 120 has higher directivity, the transmission distance of the visible light communication signal can be extended.

[0035] Furthermore, the terminal-side visible light transmission unit 130 may transmit a visible light communication signal on which identification information identifying the visible light communication access point (AP) formed by the VLC unit 100 (visible light communication device) is multiplexed. This identification information only needs to be information that can uniquely identify the VLC unit 100 (VLC AP), and may be a unique ID or number, or information such as the name of the VLC unit 100. In addition, this identification information may indicate the location of the VLC unit 100 (which may be a geographical location or a logical location on the network).

[0036] The terminal-side visible light transmission unit 130 may transmit a visible light communication signal with the identification information of the VLC unit 100 (VLC AP) multiplexed on it only during a predetermined period other than the period during which other access points in visible light communication transmit a visible light communication signal with other identification information multiplexed on it that identifies the other access point.

[0037] Specifically, the terminal-side visible light transmission unit 130 can transmit a visible light communication signal with its own identification information multiplexed on it for a certain period of time, except during the period when other VLC units 100 (visible light communication devices) connected in a daisy chain transmit a visible light communication signal with the identification information of the other VLC units 100 multiplexed on it.

[0038] In a daisy-chain configuration, the same visible light communication signal relayed from the upstream side is distributed and relayed among multiple VLC units 100 (which may include VLC adapters 70). Therefore, in order for the UE 200 to report via UL which VLC unit 100 it received the visible light communication signal from, it is necessary to multiplex and transmit only one piece of identification information into the visible light communication signal at the same time. By transmitting a visible light communication signal with the identification information multiplexed into it as described above, the terminal-side visible light transmission unit 130 enables the UE 200 to identify which VLC unit 100 transmitted the visible light communication signal it received.

[0039] The terminal-side visible light transmission unit 130 may multiplex identification information into the visible light communication signal using wavelength division multiplexing. Specifically, the terminal-side visible light transmission unit 130 may multiplex identification information of a specific VLC unit 100 into the visible light communication signal using wavelength division multiplexing.

[0040] The terminal-side visible light transmitting unit 130 may transmit a visible light communication signal based on instructions from the CCU 30 when the CCU 30 (communication control device) recognizes that the UE 200 has received a visible light communication signal from another visible light communication access point (which may be interpreted as the VLC unit 100) installed around the VLC unit 100 (visible light communication device).

[0041] Specifically, as described above, the UE 200 may report the identification information of the VLC unit 100, which is multiplexed into the visible light communication signal, to the CCU 30 via UL over the mobile communication network. The terminal-side visible light transmission unit 130 can transmit a visible light communication signal with its own device (VLC unit 100) multiplexed into it, based on instructions from the CCU 30. This enables coordinated control between VLC units 100, such as transmitting a visible light communication signal from a VLC AP located near the VLC AP (VLC unit 100) currently receiving the visible light communication signal from the UE 200, thereby increasing the possibility of the UE 200 handing over to another VLC unit 100 and continuing DL reception by the VLC.

[0042] The control unit 140 controls each functional block that constitutes the VLC unit 100. Specifically, the control unit 140 controls the reception of visible light communication signals by the upstream visible light receiving unit 110, and the transmission of visible light communication signals by the downstream visible light transmitting unit 120 and the terminal side visible light transmitting unit 130.

[0043] Furthermore, the control unit 140 may control the multiplexing of the VLC unit 100 identification information into the visible light communication signal transmitted by the terminal-side visible light transmission unit 130. Specifically, the control unit 140 may determine, based on instructions from the CCU 30, the identification information of the VLC unit 100 to be multiplexed into the visible light communication signal transmitted by the downstream-side visible light transmission unit 120 and / or the terminal-side visible light transmission unit 130.

[0044] (2.2) VLC Adapter 70 As shown in Figure 3, the VLC adapter 70 includes a visible light transmitting unit 71, a visible light transmitting unit 73, a terminal-side visible light transmitting unit 75, and a control unit 77.

[0045] The visible light transmitter 71 can be connected to a communication network. Specifically, the visible light transmitter 71 provides a connection function to the communication network 20. More specifically, the visible light transmitter 71 may be equipped with a network interface for connecting to the communication network 20 and support data transmission and reception with the communication network 20. This network interface may be wired or wireless.

[0046] The visible light transmitting unit 73 transmits a visible light communication signal to the VLC unit 100 (visible light communication device). Specifically, the visible light transmitting unit 73 transmits a visible light communication signal to the VLC unit 100 connected downstream. The visible light transmitting unit 73 may transmit a visible light communication signal to a downstream communication device by converting the data received by the visible light transmitting unit 71 (which may include user data from the user plane and control data from the control plane) into a visible light communication signal and relaying it.

[0047] The terminal-side visible light transmitter 75 transmits a visible light communication signal to the UE 200. Specifically, the terminal-side visible light transmitter 75 may transmit a visible light communication signal to the downstream communication device by relaying the visible light communication signal received by the upstream-side visible light receiver 110.

[0048] Furthermore, the coverage (which may be interpreted as directivity) of the visible light communication signal transmitted by the visible light transmitter 73 (hereinafter referred to as VLC 1 as appropriate) may be narrower than the coverage of the visible light communication signal transmitted by the terminal-side visible light transmitter 75 (hereinafter referred to as VLC 2 as appropriate). In other words, it is preferable that the directivity of the visible light communication signal transmitted by the terminal-side visible light transmitter 75 is wider than the directivity of the visible light communication signal transmitted by the visible light transmitter 73. This makes it easier for the UE 200 to be located within the coverage of the visible light communication signal, thereby increasing the possibility of DL reception by VLC.

[0049] On the other hand, since the visible light communication signal transmitted by the visible light transmission unit 73 has higher directivity, the transmission distance of the visible light communication signal can be extended.

[0050] The control unit 77 controls each functional block that constitutes the VLC adapter 70. Specifically, the control unit 77 controls data transmission and reception with the communication network 20 by the visible light transmission unit 71, and the transmission of visible light communication signals by the visible light transmission unit 73 and the terminal-side visible light transmission unit 75.

[0051] Furthermore, the control unit 77 may control the identification information of the VLC unit 100 which is multiplexed in the visible light communication signal transmitted by the terminal-side visible light transmission unit 75 and / or the terminal-side visible light transmission unit 130 of the VLC unit 100.

[0052] The control unit 77 may control the transmission timing of the visible light communication signal by the terminal-side visible light transmission unit 130 of the VLC unit 100 based on instructions from the CCU 30 (communication control device). The control unit 77 may also control the transmission timing of the visible light communication signal by the terminal-side visible light transmission unit 75. In this embodiment, the control unit 77 may constitute a transmission timing control unit. Furthermore, the visible light communication signal may include identification information of any of the multiple VLC units 100 connected in a daisy-chain.

[0053] Specifically, the control unit 77 may, based on instructions from the CCU 30, transmit a control signal to a specific VLC unit 100 to transmit a visible light communication signal for the UE 200. This control signal may be wavelength-multiplexed, similar to the identification information.

[0054] (3) Operation of the communication system 10 Next, the operation of the communication system 10 will be described. Specifically, the operation of the UE 200 regarding handover between VLC units 100 (which may include the VLC adapter 70) (including the coordinated operation between the VLC units 100) will be described.

[0055] (3.1) Operation overview The VLC adapter 70 may control the relay route of visible light communication signals by multiple VLC units 100 connected in a daisy-chain. Specifically, the VLC adapter 70 may instruct the multiple VLC units 100 to switch the VLC elements that output visible light communication signals. This instruction may be based on an instruction from the CCU 30.

[0056] The visible light communication signal may include identification information (e.g., an identification number) of the VLC unit 100, as described above. A different identification number may be assigned to each relay route. When the UE 200 receives the visible light communication signal from the VLC unit 100, it may obtain the identification number. By reporting the identification number to the communication network 20 (CCU 30), the UE 200 can identify the VLC element (VLC unit 100 or VLC adapter 70) that output the visible light communication signal.

[0057] The CCU 30 may determine the relay route for the visible light communication signal (the VLC unit 100 that outputs the visible light communication signal to the UE 200) based on the identification number reported by the UE 200. The CCU 30 may also estimate the location of the UE 200 based on the identification number reported by the UE 200.

[0058] This operation by the CCU 30, VLC adapter 70, and VLC unit 100 enables handover between VLC units 100 of the UE 200. Furthermore, by controlling the visible light communication signal for the UE 200 in this way, the transmission of visible light communication signals from VLC units 100 that are not in the vicinity of the UE 200 can be stopped, thus contributing to reduced power consumption.

[0059] (3.2) Example of operation Because the coverage of the visible light communication signal transmitted from one VLC element (VLC unit 100) is narrow, when the UE 200 moves, it falls outside that coverage, requiring a handover to the visible light communication signal coverage transmitted from another VLC element.

[0060] When multiple VLC units 100, as shown in Figure 1, relay a visible light communication signal with the same content and transmit it to the UE 200, it is difficult to identify the source VLC element (VLC unit 100) from the received visible light communication signal.

[0061] In this example, by multiplexing the identification information (such as an identification number) of the VLC unit 100 into the visible light communication signal, the handover of the UE 200 between VLC units 100 can be facilitated, and the accuracy of estimating the position of the UE 200 can be improved.

[0062] Specifically, a simplified version of the mechanism used in mobile communication networks (cellular communication) may be applied. When VLC is used, the UE 200's movement speed is expected to be relatively slow, so complex handover control like that required in mobile communication networks is not necessary.

[0063] In order to allow UE 200 to join (connect) to the communication network via VLC AP, the VLC AP (VLC unit 100) that periodically transmits visible light communication signals may be switched. As described above, each visible light communication signal for UE 200 may be assigned a unique identification number, and UE 200 may report the identification number contained in the received visible light communication signal to CCU 30 via the mobile communication network.

[0064] If UE 200 moves and is out of coverage of the currently received visible light communication signal, and the DL by VLC is disconnected, the VLC AP (VLC unit 100) that periodically transmits the visible light communication signal may be switched, similar to the method of joining (connecting) to the communication network described above. However, the VLC AP (VLC unit 100) to be switched may be limited to VLC APs in the vicinity (or nearby) of the VLC AP that was the source of the visible light communication signal that UE 200 was receiving. This can shorten the handover time between VLC APs for UE 200.

[0065] Figure 4 shows an example of switching operation of a visible light communication signal from a VLC AP. As shown in Figure 4, a VLC adapter 70 and multiple VLC units 100 are connected in a daisy-chain. The VLC adapter 70 may control the relay route of the visible light communication signal. Specifically, the visible light communication signal (VLC 2) from the VLC unit 100 may be switched over as time progresses.

[0066] As described above, identification information such as an identification number that can identify the VLC AP that transmits the visible light communication signal may be inserted into the visible light communication signal. Figure 4 shows an example in which identification number (#1) is inserted when the VLC adapter 70 transmits the visible light communication signal, and identification number (#2) is inserted when the VLC unit 100 connected to the VLC adapter 70 transmits the visible light communication signal. Identification number (#1) is assigned to the VLC adapter 70, and identification number (#2) is assigned to the VLC unit 100 connected to the VLC adapter 70.

[0067] Figure 5 shows example 2 of the switching operation of visible light communication signals from VLC APs. In Figure 5, the VLC adapter 70 and multiple VLC units 100 work in coordination to support handover between VLC APs of the UE 200.

[0068] As shown in Figure 5, during a UE 200 handover, visible light communication signals (VLC 2) from multiple VLC APs may be turned on (simultaneously transmitted). In this case, the transmission of visible light communication signals from VLC units 100 located at the destination may be turned on by predicting the UE 200's movement path.

[0069] For example, as shown in Figure 5, if UE 200 has previously handed over from VLC adapter 70 to VLC unit 100 connected to VLC adapter 70, it may be assumed that UE 200 is moving in the direction of the arrow in the figure, and the transmission of visible light communication signals from VLC unit 100 located in that direction of movement may be turned on.

[0070] This makes it possible to reduce the power consumption of multiple VLC units 100 connected in a daisy-chain while shortening the delay until the handover is completed.

[0071] (4) Other embodiments Although embodiments have been described above, it will be obvious to those skilled in the art that the invention is not limited to those embodiments described and that various modifications and improvements are possible.

[0072] For example, in the above description, configure, activate, update, indicate, enable, specify, and select may be interpreted as interchangeable. Similarly, link, associate, correspond, and map may be interpreted as interchangeable, and allocate, assign, monitor, and map may also be interpreted as interchangeable.

[0073] Furthermore, "specific," "dedicated," "UE specific," and "UE individual" may be interpreted interchangeably. Similarly, "common," "shared," "group-common," "UE common," and "UE shared" may be interpreted interchangeably.

[0074] In this disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "quasi-co-location (QCL)," "transmission configuration indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," and "panel" may be used interchangeably.

[0075] Furthermore, the block diagrams (Figures 2 and 3) used in the description of the embodiments above show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Moreover, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software.

[0076] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In any case, as mentioned above, the method of implementation is not particularly limited.

[0077] Furthermore, the VLC adapter 70 and VLC unit 100 (the device) described above may function as a computer that processes the wireless communication method of this disclosure. Figure 6 shows an example of the hardware configuration of the device. As shown in Figure 6, the device may be configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, and bus 1007.

[0078] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the device may include one or more of the devices shown in the diagram, or it may be configured to omit some of the devices.

[0079] Each functional block of the device (see Figures 2 and 3) is implemented by any hardware element of the computer device, or a combination of such hardware elements.

[0080] Furthermore, each function in the device is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the memory 1002 and storage 1003.

[0081] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, and so on.

[0082] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. Moreover, the above-mentioned various processes may be executed by one processor 1001, or by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunications line.

[0083] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store a program (program code), software modules, etc., that can execute a method according to one embodiment of this disclosure.

[0084] Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. Storage 1003 may also be called an auxiliary storage device. The recording medium described above may also be, for example, a database, server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0085] The communication device 1004 is hardware (transceiver / receiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also called a network device, network controller, network card, communication module, etc.

[0086] The communication device 1004 may be configured to include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0087] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0088] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0089] Furthermore, the device may include hardware such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), and a field-programmable gate array (FPGA), and some or all of each functional block may be implemented by such hardware. For example, processor 1001 may be implemented using at least one of these hardware components.

[0090] Furthermore, notification of information is not limited to the embodiments / models described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or combinations thereof. RRC signaling may also be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0091] Each aspect / embodiment described herein may be applied to at least one of systems utilizing Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (where x is, for example, an integer or decimal), Future Radio Access (FRA), New Radio (NR), W-CDMA®, GSM®, CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth®, and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0092] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0093] The specific operations described in this disclosure as being performed by a base station may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal can be performed by the base station and at least one other network node (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station, it may also be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0094] Information and signals (such as data) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). Input and output may occur via multiple network nodes.

[0095] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be sent to other devices.

[0096] The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0097] Each aspect / embodiment described herein may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0098] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0099] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0100] The information, signals, etc. described in this disclosure may be represented using any of the various different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0101] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0102] The terms “system” and “network” as used in this disclosure are interchangeable.

[0103] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0104] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not restrictive in any way.

[0105] In this disclosure, terms such as "Base Station (BS)," "wireless base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0106] A base station can house one or more (e.g., three) cells (also called sectors). If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0107] The terms "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base stations and base station subsystems that provide communication services in this coverage.

[0108] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform information-based control or operation.

[0109] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0110] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate term.

[0111] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes the case when the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station may include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0112] Furthermore, the term "base station" in this disclosure may be interpreted as "mobile station" (user terminal, hereinafter the same). For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). In this case, the mobile station may have the functions that a base station has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc. may be interpreted as side channel (or side link).

[0113] Similarly, the term "mobile station" in this disclosure may be interpreted as "base station." In this case, the base station may be configured to have the functions that a mobile station has.

[0114] A wireless frame may consist of one or more frames in the time domain. Each of these one or more frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0115] Numerology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerology may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0116] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol). A slot may also be a time unit based on neurology.

[0117] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called a PDSCH (or PUSCH) mapping type B.

[0118] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0119] For example, one subframe may be called a Transmit Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0120] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user terminal to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0121] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0122] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute this minimum time unit of scheduling may be controlled.

[0123] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0124] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0125] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0126] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0127] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0128] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0129] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology on a given carrier. Here, the common RBs may be identified by an index of the RBs relative to the carrier's common reference point. PRBs may be defined and numbered within a BWP.

[0130] A BWP may include BWPs for UL (UL BWP) and BWPs for DL ​​(DL BWP). One or more BWPs may be set within a single carrier for a UE.

[0131] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0132] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0133] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0134] The reference signal can also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

[0135] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0136] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0137] Any reference to elements using designations such as “First,” “Second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the First and Second elements do not imply that only two elements may be employed therein, or that the First element must precede the Second element in any way.

[0138] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0139] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0140] The terms “determining” and “determining” as used in this disclosure may encompass a wide variety of actions. “Determining” and “determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in a table, database, or other data structure), or ascertaining. “Determining” and “determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having "judgmented" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having "judgmented" or "decided" about some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0141] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0142] (Note) The above disclosure may also be expressed as follows: The first feature is a visible light communication device that performs visible light communication using a visible light communication signal using visible light, comprising an upstream visible light receiving unit that receives the visible light communication signal from an upstream communication device, and a terminal-side visible light transmitting unit that transmits the visible light communication signal to a terminal, wherein the terminal-side visible light transmitting unit transmits the visible light communication signal on which identification information identifying the access point of the visible light communication formed by the visible light communication device is multiplexed.

[0143] The second feature is that, in the first feature, the terminal-side visible light transmitting unit transmits the visible light communication signal on which the identification information is multiplexed only during a predetermined period other than the period during which other access points of the visible light communication transmit the visible light communication signal on which other identification information that identifies the other access points is multiplexed.

[0144] The third feature is that, in the first or second feature, the terminal-side visible light transmitting unit multiplexes the identification information into the visible light communication signal using wavelength division multiplexing.

[0145] The fourth feature is that, in the first to third features, the terminal-side visible light transmitting unit transmits the visible light communication signal based on instructions from the communication control device when the communication control device recognizes that the terminal has received the visible light communication signal from another access point of the visible light communication installed around the visible light communication device. [Explanation of Symbols]

[0146] 10 Communication Systems 20 Communication Networks 30 CCU 50 Wireless base stations 70 VLC adapter 71 Visible light transmitter 73 Visible light transmitter 75 Terminal-side visible light transmitting unit 77 Control Unit 100 VLC units 110 Upstream visible light receiving unit 120 Downstream visible light transmitter 130 Terminal-side visible light transmission unit 140 Control Unit 200 UE 1001 Processor 1002 memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus

Claims

1. A visible light communication device that performs visible light communication using visible light communication signals, An upstream visible light receiving unit that receives the visible light communication signal from the upstream communication device, A terminal-side visible light transmission unit that transmits the visible light communication signal toward the terminal, and Equipped with, The terminal-side visible light transmitting unit is a visible light communication device that transmits a visible light communication signal on which identification information identifying the access point of the visible light communication formed by the visible light communication device is multiplexed.

2. The visible light communication device according to claim 1, wherein the terminal-side visible light transmitting unit transmits the visible light communication signal on which the identification information is multiplexed only during a predetermined period other than the period during which other access points of the visible light communication transmit the visible light communication signal on which other identification information is multiplexed to identify the other access points.

3. The visible light communication device according to claim 1, wherein the terminal-side visible light transmitting unit multiplexes the identification information into the visible light communication signal using wavelength division multiplexing.

4. The visible light communication device according to claim 1, wherein the terminal-side visible light transmitting unit transmits the visible light communication signal based on instructions from the communication control device when the communication control device recognizes that the terminal has received the visible light communication signal from another access point of the visible light communication installed around the visible light communication device.

5. A visible light communication device that performs visible light communication using visible light communication signals, A visible light communication adapter device having a function to connect to a communication network and performing the visible light communication described above, A communication system including, The visible light communication device is An upstream visible light receiving unit that receives the visible light communication signal from the upstream communication device, A terminal-side visible light transmission unit that transmits the visible light communication signal toward the terminal, and Equipped with, The visible light communication adapter device is A visible light transmitting unit that transmits the visible light communication signal to the visible light communication device, A transmission timing control unit controls the transmission timing of the visible light communication signal by the terminal-side visible light transmission unit based on instructions from the communication control device. Equipped with, The terminal-side visible light transmitting unit is a communication system that transmits a visible light communication signal on which identification information identifying the access point of the visible light communication formed by the visible light communication device is multiplexed.

6. A communication method in a visible light communication device that performs visible light communication using visible light communication signals, The steps include receiving the visible light communication signal from the upstream communication device, The steps include transmitting the visible light communication signal to the terminal and Includes, A communication method comprising the step of transmitting the visible light communication signal, wherein the visible light communication signal is multiplexed with identification information that identifies the access point of the visible light communication formed by the visible light communication device.

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