Wireless communication system, terminal, and communication method

Abstract

In this radio communication system, which comprises a base station and a plurality of terminals and which operates using a licensed band: the base station allocates to the plurality of terminals a radio resource for transmission that allows duplication between the plurality of terminals; and all or some of the plurality of terminals transmit using the allocated radio resource after executing listen before talk (LBT).

Description

Technical Field

[0001] The present invention relates to a wireless communication system operating on a licensed band.

Background Art

[0002] In a wireless communication system such as NR or LTE defined by 3GPP, a terminal and a base station can communicate in a licensed band, which is a frequency band permitted by an operator, and in an unlicensed band, which is a frequency band other than this.

[0003] In the licensed band, the system side assigns exclusive (non-overlapping) radio resources to a plurality of terminals to perform communication, thereby preventing channel contention and data collision between the plurality of terminals. Also, in the unlicensed band, before transmission, channel sensing is performed, and LBT (Listen before talk), which confirms that it is idle and then performs transmission, is carried out.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the communication method using the licensed band in the prior art, exclusive radio resources are assigned to a plurality of terminals in order to avoid data collision. However, when exclusive radio resources are assigned to each terminal and the assigned terminal cannot use up the assigned radio resources, the resource utilization efficiency decreases.

[0006] The present invention has been made in view of the above points, and an object thereof is to provide a technique for improving resource utilization efficiency while avoiding collisions in a license band.

Means for Solving the Problems

[0007] According to the disclosed technique, there is provided a wireless communication system including a base station and a plurality of terminals, and operated in a license band, wherein the base station allocates wireless resources for transmission allowing duplication among the plurality of terminals to the plurality of terminals, and all or some of the plurality of terminals perform transmission using the allocated wireless resources after executing LBT (Listen before talk). A wireless communication system is provided.

Effects of the Invention

[0008] According to the disclosed technique, it becomes possible to provide a technique for improving resource utilization efficiency while avoiding collisions in a license band.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention (the present embodiment) will be described with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

[0011] Hereinafter, as embodiments of the present invention, a first embodiment and a second embodiment will be described. The first embodiment is an embodiment in which the present invention is applied to uplink communication, and the second embodiment is an embodiment in which the present invention is applied to communication between terminals. The first embodiment and the second embodiment can be implemented in combination.

[0012] The wireless communication system in each embodiment mainly assumes an NR system (or an LTE system) defined by 3GPP, but is not limited thereto. For example, the technology according to the present invention can also be applied to 3G and 6G.

[0013] (First Embodiment) In the first embodiment, for uplink communication by means of pre-transmission permission using a licensed band in a wireless communication system, the base station permits a plurality of terminals to use non-exclusive (i.e., shared with overlap) radio resources to improve resource utilization efficiency. Since non-exclusive radio resource use is permitted for each terminal, each terminal executes an LBT operation when transmitting an uplink signal.

[0014] Note that in the first embodiment, the configured grant method is used as an example, but the technology according to the present invention can also be applied to methods other than this method. For example, the technology according to the present invention can also be applied to semi-persistent scheduling or dynamic scheduling. However, in dynamic scheduling, in many cases, radio resources are allocated based on the transmission request amount, so it is considered that a state where the allocated radio resources cannot be used up does not occur frequently. Therefore, it is considered that the application opportunities and expected effects for dynamic scheduling are less than others. Hereinafter, the content of the first embodiment will be described in more detail.

[0015] <Regarding the problem> In 5G NR (New Radio), which is the wireless communication system assumed in this embodiment, when performing uplink communication by a terminal, there are defined a method (dynamic grant) of giving a transmission permission to the terminal from the base station each time transmission is performed, and a method (configured grant) of giving a pre-transmission permission to the terminal from the base station in advance (for example, Non-Patent Document 1). In the pre-transmission permission, the time-frequency resources (hereinafter described as radio resources or resources) that can be used by the terminal for uplink transmission are specified. In this specification, the period in which transmission can be performed using the resources is also specified.

[0016] In the method of giving a pre-transmission permission from the base station to the terminal, in the prior art, in order to avoid channel contention and data collision, it is conceivable to allocate exclusive radio resources among a plurality of terminals. However, when exclusive radio resources are allocated among terminals, the resource utilization efficiency decreases.

[0017] This will be described with reference to FIG. 1. In FIG. 1, a base station 200, a terminal 100-A, and a terminal 100-B existing within the communication area (cell) of the base station 200 are shown. In the example of FIG. 1, it is assumed that resource a and resource b are respectively allocated to the terminal 100-A and the terminal 100-B from the base station 200 by prior transmission permission. Resource a and resource b are exclusive. Here, "exclusive" means that even if the terminal 100-A transmits using resource a in all transmission opportunities and the terminal 100-B transmits using resource b in all transmission opportunities, no collision occurs. "Exclusive" may be paraphrased as "non-overlapping".

[0018] In this case, the terminal 100-A performs transmission using resource a at a certain timing within the allocated period. However, resource a is not used in time periods other than during transmission. Similarly, the terminal 100-B performs transmission using resource b at a certain timing within the allocated period. However, resource b is not used in time periods other than during transmission. That is, in the prior art, even when the resource allocated to a terminal by prior transmission permission is not used by that terminal, other terminals cannot use that resource, so the resource utilization efficiency decreases.

[0019] <Processing content of the first embodiment> In the first embodiment, in order to solve the above problems, the base station 200 pre-permits the uplink communication transmission of a plurality of terminals 100 using non-exclusive radio resources. Since the use of non-exclusive radio resources is pre-permitted, if each terminal 100 freely performs transmission according to the permission, collisions of transmission data and the like may occur. Therefore, in this embodiment, the terminal 100 performs LBT and then performs transmission. The LBT method is not limited to a specific method. For example, the LBT method for the NR-U neighboring frequency band defined by 3GPP for unlicensed bands can be applied.

[0020] Regarding the execution of LBT, in the first embodiment, there are the following patterns 1 to 3. Regarding which pattern among patterns 1 to 3 to implement, it may be notified from the base station 200 to the terminal 100, or it may be predetermined for each base station 200 (cell).

[0021] Pattern 1: In pattern 1, the terminal 100 having the pre - transmission permission setting performs LBT and then transmits when transmitting the pre - permitted uplink communication.

[0022] Pattern 2: In pattern 2, the terminal 100 having the pre - transmission permission setting performs LBT and then transmits when transmitting the pre - permitted uplink communication if it has the ability to execute LBT (terminal Capability). A terminal without the terminal Capability transmits without performing LBT when transmitting the pre - permitted uplink communication.

[0023] Pattern 3: In pattern 3, only when it is specified by an instruction from the NW (network) side (specifically, the base station 200) to the terminal 100 to transmit in the method of pattern 1, the terminal 100 having the pre - transmission permission setting performs LBT and then transmits when transmitting the pre - permitted uplink communication. The signal used for the instruction from the base station 200 to the terminal 100 may be DCI, MAC CE, or an RRC message.

[0024] <Operation example of the first embodiment> An operation example will be described with reference to FIGS. 2 and 3. Here, pattern 1 is assumed. Alternatively, in pattern 2, it may be assumed that all terminals 100 have the ability to perform LBT. Alternatively, in pattern 3, it may be assumed that the base station 200 instructs each terminal 100 to execute the operation in pattern 1.

[0025] In both FIGS. 2 and 3, assume that a configured grant in which the same radio resource (referred to as resource a) is assigned to terminal 100-A and terminal 100-B respectively is set. Also assume that the transmission period in the configured grant is the same for terminal 100-A and terminal 100-B.

[0026] As shown in FIG. 2, at S1, terminal 100-A is transmitting using resource a. In this situation, at S2, when terminal 100-B attempts to transmit using resource a, since it detects that resource a is in use by LBT, it waits without transmitting.

[0027] As shown in FIG. 3, at S3, terminal 100-A has completed the transmission of the data in the transmission queue and is in a data waiting state. At S4, after terminal 100-B performs LBT and detects that resource a is available, it transmits using resource a.

[0028] <Regarding the effects of the first embodiment> In the first embodiment, since base station 200 pre-permits the transmission of uplink communication using non-exclusive radio resources to a plurality of terminals 100, it is possible to improve the utilization efficiency of the radio resources in the area of base station 200 and expand the uplink transmission capacity.

[0029] Also, in pattern 1, since each terminal 100 executes LBT when transmitting pre-permitted uplink communication, other settings and messaging (signaling) are not required. Note that in pattern 1, it is assumed that all terminals 100 have the ability to execute the operation of pattern 1.

[0030] In pattern 2, since only the terminals 100 having the terminal Capability of the operation of pattern 1 transmit in the method of pattern 1, even when terminals 100 without an LBT function and terminals 100 with an LBT function are mixed in the area, the operation according to this embodiment can be realized without differentiating messaging (signaling) between them.

[0031] In Pattern 3, transmission is performed in the method of Pattern 1 only when specified by an instruction from the NW side to the terminal 100. Therefore, for each terminal 100 from the NW side or according to the terminal environment, the execution of the operations according to this embodiment can be flexibly instructed.

[0032] Hereinafter, examples of the specific configuration and operations in the first embodiment will be described.

[0033] <Configuration and Operations of the System> FIG. 4 shows an example of the overall configuration of the wireless communication system in the first embodiment. The overall configuration of the wireless communication system is the same as that of a configuration such as NR, and includes a core NW 300, a base station 200, and a plurality of terminals 100. The core NW 300 is provided with a transfer device, a control device, and the like.

[0034] As shown in FIG. 4, a pre-transmission permission resource is specified from the base station 200 to the terminal 100 by an uplink communication pre-transmission permission message (e.g., ConfiguredGrantConfig). Regarding the transmission method by pre-transmission permission, there are Type 1 and Type 2.

[0035] In Type 1, the terminal 100 performs transmission using the resources pre-permitted by the RRC permission message. In Type 2, the terminal 100 receives Enable / Disable (usable / unusable) from the base station 200 by DCI for the resources pre-permitted by the RRC permission message. The terminal 100 performs transmission using the resources instructed by Enable in the DCI.

[0036] With reference to the flowchart of FIG. 5, an example of the operation of the terminal 100 in the first embodiment will be described. As a premise of the flowchart of FIG. 5, it is assumed that a transmission permission resource has already been pre-notified from the base station 200 to the terminal 100.

[0037] In S101, a transmission signal (which may also be called transmission data) is accumulated in the transmission queue of the terminal 100.

[0038] In S102, the terminal 100 executes LBT triggered by the accumulation of transmission signals in the transmission queue, and performs transmission using pre-approved resources only when interference from other terminals (or the base station 200) is not detected as a result of the LBT.

[0039] (Second Embodiment) Next, the second embodiment will be described. In the second embodiment, for device - to - device communication (which may also be called sidelink, D2D, etc.) in a wireless communication system operating in a licensed band, the base station permits non - exclusive use of wireless resources by a plurality of terminals to improve resource utilization efficiency. Since non - exclusive use of wireless resources is permitted to the terminals, the terminals execute the LBT operation when transmitting device - to - device communication. The content of the second embodiment will be described in more detail below.

[0040] <Regarding the Problem> In 5G NR (New Radio), which is the wireless communication system assumed in this embodiment, device - to - device communication is defined. In NR device - to - device communication, there are Mode1 in which the base station 200 allocates transmission resources (for PSSCH and PSCCH) to the terminal 100 by giving a transmission permission, and Mode2 in which the terminal 100 autonomously determines the transmission resources.

[0041] The second embodiment assumes Mode1. In Mode1, a method of giving a transmission permission to each terminal from the NW side (base station) each time transmission is performed (dynamic grant) and a method of giving a transmission permission in advance (configured grant) are defined. The second embodiment is applicable to both dynamic grant and configured grant.

[0042] In a method of giving transmission permission from a base station to a terminal in terminal-to-terminal communication, in order to avoid signal collisions and the like, it is conceivable to allocate exclusive radio resources among a plurality of transmitting terminals. However, if the terminal is made to perform transmission using exclusive radio resources, the resource utilization efficiency will decrease. On the other hand, if the terminal is made to perform transmission using non-exclusive radio resources (radio resources that allow duplication), collisions between signals will occur and the communication quality will deteriorate.

[0043] The above problems will be described with reference to FIGS. 6 and 7. In FIGS. 6 and 7, a base station 200 and terminals 100-A, 100-B, 100-C, and 100-D existing within the communication area (cell) of the base station 200 are shown.

[0044] First, with reference to FIG. 6, the problem of decreased radio resource utilization efficiency will be described. In FIG. 6, exclusive resources are allocated to each terminal 100 from the base station 200 as resources for transmission in terminal-to-terminal communication. At this time, for example, when terminal 100-A is performing transmission using the allocated resources, at that point, other terminals 100 do not perform transmission using the same resources as that resource.

[0045] For example, even if terminal 100-D performs transmission using the same resources as terminal 100-A and does not interfere with other terminals 100 (when the distance between terminals is large), it does not perform transmission. Therefore, in the case of FIG. 6, the utilization efficiency of radio resources decreases.

[0046] Next, with reference to FIG. 7, a case where radio wave interference due to signal collision occurs will be described. In the example of FIG. 7, the same resources are allocated to terminal 100-A and terminal 100-D. In this case, when terminal 100-A is performing transmission using the resource, terminal 100-D also performs transmission using the same resource.

[0047] The signal transmitted from terminal 100-A to terminal 100-B using the resource is a desired wave and is received by terminal 100-B. The signal transmitted from terminal 100-D to terminal 100-C using the resource is a desired wave and is received by terminal 100-C. However, since the signal from terminal 100-A to terminal 100-C causes interference, the communication quality at terminal 100-C deteriorates.

[0048] <Processing details of the second embodiment> In the second embodiment, in order to solve the above problems, the base station 200 permits a plurality of terminals 100 to perform transmission of inter-terminal communication using non-exclusive radio resources (radio resources allowing duplication). Since the use of non-exclusive radio resources is permitted, if each terminal 100 freely performs transmission according to the permission, collisions of transmission data and the like may occur. Therefore, in this embodiment, the terminal 100 performs LBT before performing transmission. The method of LBT is not limited to a specific method. For example, the LBT method of the NR-U neighboring frequency band defined by 3GPP for unlicensed bands can be applied.

[0049] Regarding the execution of LBT, in the second embodiment, there are the following patterns 1 to 4. Regarding which pattern among patterns 1 to 4 is to be implemented, it may be notified from the base station 200 to the terminal 100, or it may be determined in advance for each base station 200 (cell).

[0050] Pattern 1: In pattern 1, the terminal 100 permitted to perform transmission of inter-terminal communication performs LBT before performing transmission when transmitting using the permitted resource. In pattern 1, LBT is performed before transmission in both the case of performing permission (resource allocation) every time of transmission (dynamic grant) and the case of performing transmission with a pre-transmission permission (configured grant).

[0051] Pattern 2: In Pattern 2, when the terminal 100 performs transmission with prior transmission permission, it performs LBT and then conducts the transmission. When the terminal 100 performs transmission with a transmission permission (dynamic grant) for each transmission, it may perform the transmission without performing LBT.

[0052] Pattern 3: In Pattern 3, when the terminal 100 has the ability to execute LBT (terminal Capability), it conducts the transmission after performing LBT in Pattern 1 or Pattern 2. A terminal without the said terminal Capability conducts the transmission without performing LBT.

[0053] Pattern 4: In Pattern 4, only when the NW (network) side (specifically, the base station 200) designates that the terminal 100 conducts transmission in the method of Pattern 1 or Pattern 2, the terminal 100 conducts the transmission in the designated method (Pattern 1 or Pattern 2).

[0054] The signal used for the instruction from the base station 200 to the terminal 100 may be a DCI, a MAC CE, or an RRC message.

[0055] <Operation Example of the Second Embodiment> An operation example will be described with reference to FIG. 8. Here, Pattern 1 is assumed. Alternatively, in Pattern 2, prior transmission permission may be given. Alternatively, in Pattern 3, it may be assumed that all terminals 100 have the ability of LBT. Alternatively, in Pattern 4, it may be assumed that the base station 200 instructs each terminal 100 to execute the operation in Pattern 1 (or Pattern 2).

[0056] In S11, the base station 200 permits (or pre-permits) the transmission using the same radio resource for each of the terminal 100-A and the terminal 100-D. Further, the base station 200 permits (or pre-permits) the transmission using the same radio resource for each of the terminal 100-E and the terminal 100-H.

[0057] Let the same resource assigned to terminal 100-A and terminal 100-D be "Resource X", and the same resource assigned to terminal 100-E and terminal 100-H be "Resource Y".

[0058] In S12, terminal 100-A is transmitting using Resource X, the desired wave reaches terminal 100-B, and the interference wave reaches terminal 100-D. In S13, since transmission data has been generated at terminal 100-D (data has been accumulated in the transmission queue), in order to perform transmission using Resource X, it is confirmed by sensing whether another terminal is transmitting using Resource X. That is, LBT is performed.

[0059] Since terminal 100-D detects that the interference wave of Resource X has arrived, it waits for transmission to avoid radio wave interference at the receiving terminal (terminal 100-B).

[0060] In S14, terminal 100-E is transmitting using Resource Y, the desired wave reaches terminal 100-F, but the interference wave does not reach the remote terminal 100-H. In S15, since transmission data has been generated at terminal 100-H (data has been accumulated in the transmission queue), in order to perform transmission using Resource Y, it is confirmed by sensing whether another terminal is transmitting using Resource Y. That is, LBT is performed.

[0061] Since terminal 100-H does not detect that the interference wave of Resource Y has arrived, it performs transmission using Resource Y. Thus, resource utilization can be made efficient. Note that depending on the LBT method, when terminal 100-H does not detect that the interference wave of Resource Y has arrived, it may also perform transmission after waiting for a predetermined time.

[0062] <Regarding the effects of the second embodiment> In the second embodiment, since the base station 200 permits the transmission in the inter-terminal communication using non-exclusive radio resources to a plurality of terminals 100, it is possible to improve the radio resource utilization efficiency in the area of the base station 200 and expand the transmission capacity.

[0063] Also, in Pattern 1, since each terminal 100 executes LBT at the time of transmission of the permitted inter-terminal communication, other settings and messaging (signaling) are not required.

[0064] In Pattern 2, since the pre-authorized terminal 100 executes LBT when performing the transmission of the inter-terminal communication, at the time of individual transmission permission by dynamic grant, transmission is LBT-free and simultaneous transmission with other terminals is possible by exclusive transmission or explicit instruction. Flexible resource utilization is possible by autonomously avoiding collisions only at the time of pre-authorization.

[0065] In Pattern 3, since only the terminal 100 having the terminal Capability of the operation of Pattern 1 or Pattern 2 performs the transmission in the method of Pattern 1 or Pattern 2, even when the terminals 100 with and without the LBT function are mixed in the area, the operation according to this embodiment can be realized without differentiating messaging (signaling) between them.

[0066] In Pattern 4, since the transmission is performed in the method of Pattern 1 or Pattern 2 only when specified by an instruction from the NW side to the terminal 100, the execution of the operation according to this embodiment can be flexibly instructed from the NW side for each terminal 100 or according to the terminal environment.

[0067] Hereinafter, examples of the specific configuration and operation in the second embodiment will be described.

[0068] <Configuration and Operation of the System> Fig. 9 shows an example of the overall configuration of the wireless communication system in the second embodiment. The overall configuration of the wireless communication system is the same as that of the first embodiment and is the same as the configuration such as NR, and includes a core NW 300, a base station 200, and a plurality of terminals 100. The core NW 300 is provided with a transfer device, a control device, and the like.

[0069] As shown in Fig. 9, from the base station 200 to the terminal 100, in the transmission permission message for inter-terminal communication, the transmission permission resource for inter-terminal communication is specified. The transmission permission (allocation of transmission resources) by the permission message is divided into two cases: the case where the terminal 100 performs it each time it transmits (dynamic grant), and the case where the transmission permission resource is specified in advance (configured grant). For example, the dynamic grant is notified by DCI, and the configured grant is notified by RRC.

[0070] <Operation Example 1> An operation example of the base station 200 and the terminal 100 when performing transmission permission each time transmission is made will be described with reference to the flowcharts of Figs. 10 and 11.

[0071] An operation example of the base station 200 will be described with reference to Fig. 10. In S201, the base station 200 receives a transmission request from the terminal 100. In S202, the base station 200 notifies the terminal 100 of the transmission permission resource.

[0072] An operation example of the terminal 100 will be described with reference to Fig. 11. In S301, the transmission signal is accumulated in the transmission queue of the terminal 100. In S302, the terminal 100 transmits a transmission request to the base station 200.

[0073] In S303, the terminal 100 receives the transmission permission resource from the base station 200. In S304, after LBT, the terminal 100 executes transmission using the specified resource only when no interference is detected.

[0074] <Operation Example 2> The operation examples of the base station 200 and the terminal 100 when pre-transmission permission is given will be described with reference to the flowchart of FIG. 12.

[0075] As a premise of the flowchart in FIG. 12, it is assumed that the transmission permission resource for device-to-device communication has already been pre-notified from the base station 200 to the terminal 100.

[0076] In S401, a transmission signal (which may also be called transmission data) is accumulated in the transmission queue of the terminal 100.

[0077] In S402, the terminal 100 executes LBT triggered by the accumulation of the transmission signal in the transmission queue, and performs transmission using the pre-permitted resources only when no interference from other terminals is detected as a result of the LBT.

[0078] (Device configuration example) Hereinafter, a device configuration example common to the first embodiment and the second embodiment will be described.

[0079] <Terminal 100> FIG. 13 is a diagram showing an example of the functional configuration of the terminal 100. As shown in FIG. 13, the terminal 100 includes a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in FIG. 13 is merely an example. As long as the operations according to the embodiments of the present invention can be executed, the functional divisions and the names of the functional units may be anything.

[0080] The transmission unit 110 creates a transmission signal from the transmission data and wirelessly transmits the transmission signal. The reception unit 120 wirelessly receives various signals and acquires signals of higher layers from the received physical layer signals. The reception unit 120 is capable of performing the LBT operation.

[0081] Further, for example, the transmission unit 110 may transmit, as D2D communication, a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), etc. to another terminal 100, and the reception unit 120 may receive a PSCCH, a PSSCH, a PSDCH, or a PSBCH, etc. from another terminal 100.

[0082] The setting unit 130 stores various setting information received from the base station 200 or another terminal 100 by the reception unit 120 in a storage device included in the setting unit 130, and reads it out from the storage device as necessary. The setting unit 130 also stores preset setting information.

[0083] The control unit 140 controls the terminal 100. The control unit 240 includes a function of determining the frequency range to be used. A functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the reception unit 120. Also, the transmission unit 110 may be called a transmitter, and the reception unit 120 may be called a receiver. Also, the control unit 140 may be called a processor.

[0084] <Base station 200> FIG. 14 is a diagram showing an example of the functional configuration of the base station 200. As shown in FIG. 14, the base station 200 includes a transmission unit 210, a reception unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in FIG. 14 is merely an example. As long as the operations according to the embodiments of the present invention can be executed, the functional division and the names of the functional units may be any.

[0085] The transmission unit 210 includes a function of generating a signal to be transmitted to the terminal 100 side and wirelessly transmitting the signal. The reception unit 220 includes a function of receiving various signals transmitted from the terminal 100 and obtaining, for example, information of a higher layer from the received signals.

[0086] The setting unit 230 stores in a storage device included in the setting unit 230 the setting information set in advance and various types of setting information to be transmitted to the terminal 100, and reads it out from the storage device as necessary.

[0087] The control unit 240 schedules the DL reception or UL transmission of the terminal 20 via the transmission unit 210. A functional unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and a functional unit related to signal reception in the control unit 240 may be included in the reception unit 220. Also, the transmission unit 210 may be called a transmitter, and the reception unit 220 may be called a receiver. Also, the control unit 240 may be called a processor.

[0088] <Hardware Configuration Example> Both the terminal 100 and the base station 200 (collectively referred to as a device) can be realized, for example, by causing a computer to execute a program. This computer may be a physical computer or a virtual machine on the cloud.

[0089] That is, the device can be realized by using hardware resources such as a CPU and a memory built into the computer to execute a program corresponding to the processing performed by the device. The above program can be recorded on a computer-readable recording medium (such as a portable memory), saved, distributed, etc. Also, it is possible to provide the above program through a network such as the Internet or e-mail.

[0090] FIG. 15 is a diagram showing a hardware configuration example of the above computer. The computer in FIG. 15 has a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, etc., which are mutually connected by a bus BS.

[0091] A program for realizing processing on the computer is provided by a recording medium 1001 such as a CD-ROM or a memory card, for example. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 via the drive device 1000 into the auxiliary storage device 1002. However, the program does not necessarily have to be installed from the recording medium 1001, and it may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program and also stores necessary files, data, etc.

[0092] When an instruction to start the program is given, the memory device 1003 reads out and stores the program from the auxiliary storage device 1002. The CPU 1004 realizes the functions related to the device according to the program stored in the memory device 1003. The interface device 1005 is used as a communication device for connecting to a network. The display device 1006 displays a GUI (Graphical User Interface) etc. by the program. The input device 1007 is composed of a keyboard, a mouse, buttons, or a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the calculation result.

[0093] (Appendix) This specification discloses at least a wireless communication system, a terminal, and a communication method according to the following respective items. (Item 1) A wireless communication system including a base station and a plurality of terminals, and operated by a licensed band, wherein the base station allocates wireless resources for transmission allowing duplication among the plurality of terminals to the plurality of terminals, and all or some of the plurality of terminals execute LBT (Listen before talk) and then perform transmission using the allocated wireless resources Wireless communication system. (Item 2) Among the plurality of terminals, a terminal equipped with an LBT function performs transmission using the allocated radio resources after executing LBT, and a terminal not equipped with an LBT function performs transmission using the allocated radio resources without executing LBT. The wireless communication system according to claim 1. (Item 3) A terminal in a wireless communication system including a base station and a plurality of terminals and operated using a licensed band, a receiving unit that receives from the base station a message for allocating radio resources for transmission that allows overlap with radio resources allocated to other terminals, a transmitting unit that performs transmission using the allocated radio resources after executing LBT (Listen before talk) by the receiving unit A terminal comprising: (Item 4) When the receiving unit receives an instruction to perform transmission after LBT from the base station, the transmitting unit performs transmission after LBT The terminal according to claim 3. (Item 5) The transmitting unit performs transmission in uplink communication or transmission in inter-terminal communication The terminal according to claim 3 or 4. (Item 6) A communication method in a wireless communication system including a base station and a plurality of terminals and operated using a licensed band, wherein the base station allocates radio resources for transmission that allows overlap among the plurality of terminals to the plurality of terminals, and all or some of the plurality of terminals perform transmission using the allocated radio resources after executing LBT (Listen before talk). Communication method.

[0094] As described above, the present embodiment has been described, but the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Description of Symbols

[0095] 100 Terminal 110 Transmitter 120 Receiver 130 Setting Unit 140 Control Unit 200 Base Station 210 Transmitter 220 Receiver 230 Setting Unit 240 Control Unit 300 Core NW 1000 Drive Device 1001 Recording Medium 1002 Auxiliary Storage Device 1003 Memory Device 1004 CPU 1005 Interface Device 1006 Display Device 1007 Input Device 1008 Output Device

Claims

1. A wireless communication system comprising a base station and a plurality of terminals, and operating in a licensed band, wherein the base station allocates wireless resources for transmission allowing overlap among the plurality of terminals to the plurality of terminals, all or some of the plurality of terminals perform transmission using the allocated wireless resources after performing LBT (Listen before talk). A wireless communication system.

2. Among the plurality of terminals, the terminals having an LBT function perform transmission using the allocated wireless resources after performing LBT, and the terminals not having an LBT function perform transmission using the allocated wireless resources without performing LBT. The wireless communication system according to Claim 1.

3. A terminal in a wireless communication system comprising a base station and a plurality of terminals, and operating in a licensed band, wherein a receiving unit that receives from the base station a message allocating wireless resources for transmission allowing overlap with wireless resources allocated to other terminals, a transmitting unit that performs transmission using the allocated wireless resources after performing LBT (Listen before talk) by the receiving unit A terminal comprising.

4. When the receiving unit receives an instruction to perform transmission after LBT from the base station, the transmitting unit performs transmission after LBT. The terminal according to Claim 3.

5. The transmitting unit performs transmission in uplink communication or transmission in terminal-to-terminal communication. The terminal according to Claim 3 or 4.

6. A communication method in a wireless communication system comprising a base station and a plurality of terminals, and operating in a licensed band, wherein the base station allocates wireless resources for transmission allowing overlap among the plurality of terminals to the plurality of terminals, all or some of the plurality of terminals perform transmission using the allocated wireless resources after performing LBT (Listen before talk). A communication method.

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