WO2016195084A1 - ユーザ端末、無線基地局及び無線通信方法 - Google Patents
ユーザ端末、無線基地局及び無線通信方法 Download PDFInfo
- Publication number
- WO2016195084A1 WO2016195084A1 PCT/JP2016/066623 JP2016066623W WO2016195084A1 WO 2016195084 A1 WO2016195084 A1 WO 2016195084A1 JP 2016066623 W JP2016066623 W JP 2016066623W WO 2016195084 A1 WO2016195084 A1 WO 2016195084A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- transmission
- user terminal
- signal
- listening
- cell
- Prior art date
Links
- 238000004891 communication Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims description 31
- 230000005540 biological transmission Effects 0.000 claims abstract description 314
- 230000008054 signal transmission Effects 0.000 claims abstract description 9
- 210000004027 cell Anatomy 0.000 description 71
- 238000012545 processing Methods 0.000 description 54
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 19
- 238000005259 measurement Methods 0.000 description 16
- 238000010586 diagram Methods 0.000 description 14
- 238000013507 mapping Methods 0.000 description 14
- 230000011664 signaling Effects 0.000 description 12
- 238000001514 detection method Methods 0.000 description 7
- 230000002776 aggregation Effects 0.000 description 5
- 238000004220 aggregation Methods 0.000 description 5
- 210000000678 band cell Anatomy 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 230000006870 function Effects 0.000 description 5
- 238000012790 confirmation Methods 0.000 description 4
- 230000009977 dual effect Effects 0.000 description 3
- 238000007726 management method Methods 0.000 description 3
- 238000012384 transportation and delivery Methods 0.000 description 3
- 239000000969 carrier Substances 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000010295 mobile communication Methods 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 101000741965 Homo sapiens Inactive tyrosine-protein kinase PRAG1 Proteins 0.000 description 1
- 102100038659 Inactive tyrosine-protein kinase PRAG1 Human genes 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 238000013439 planning Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000013468 resource allocation Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/12—Wireless traffic scheduling
- H04W72/1263—Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
- H04W72/1268—Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows of uplink data flows
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/14—Spectrum sharing arrangements between different networks
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/24—Cell structures
- H04W16/32—Hierarchical cell structures
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0453—Resources in frequency domain, e.g. a carrier in FDMA
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/12—Wireless traffic scheduling
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/20—Control channels or signalling for resource management
- H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/08—Non-scheduled access, e.g. ALOHA
- H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/02—Terminal devices
Definitions
- the present invention relates to a user terminal, a radio base station, and a radio communication method in a next-generation mobile communication system.
- LTE Long Term Evolution
- SC-FDMA Single Carrier Frequency Division Multiple Access
- LTE-A LTE Advanced or LTE enhancement
- a small cell eg, a pico cell, a femto cell, etc.
- a macro cell having a wide coverage area with a radius of several kilometers.
- Heterogeneous Network is under consideration.
- use of carriers in different frequency bands as well as in the same frequency band between a macro cell (macro base station) and a small cell (small base station) is being studied.
- LTE-U LTE Unlicensed
- LAA License-Assisted Access
- LAA-LTE LAA-LTE
- a licensed band is a band that a specific operator is allowed to use exclusively, while an unlicensed band (also called a non-licensed band) can be set up with a radio station without being limited to a specific operator. It is a band.
- an unlicensed band for example, use of a 2.4 GHz band, a 5 GHz band that can use Wi-Fi (registered trademark) or Bluetooth (registered trademark), and a 60 GHz band that can use a millimeter wave radar is being studied. . Application of such an unlicensed band in a small cell is also under consideration.
- E-UTRA Evolved Universal Terrestrial Radio Access
- E-UTRAN Evolved Universal Terrestrial Radio Access Network
- the unlicensed band is not limited to use by a specific business operator.
- the unlicensed band is not limited to the use of a specific wireless system (for example, LTE, Wi-Fi, etc.). For this reason, there is a possibility that the frequency band used in the LAA of a certain operator overlaps with the frequency band used in the LAA or Wi-Fi of another operator.
- LTE-U LTE / LTE-A system
- APs and TPs wireless access points
- eNBs wireless base stations
- the LTE-U base station / user terminal performs listening (sensing) before signal transmission, confirms whether other base stations / user terminals are communicating, and listens. Controlling transmission based on the results is under consideration. This listening operation is also called LBT (Listen Before Talk).
- the present invention has been made in view of the above points, and in a cell (for example, an unlicensed band) to which listening is applied before transmission, a user terminal, a radio base station, and a radio that can suppress a decrease in throughput.
- a cell for example, an unlicensed band
- One object is to provide a communication method.
- a user terminal is a user terminal that performs communication using at least a first cell to which listening is applied before signal transmission, a reception unit that receives a DL signal including a UL transmission instruction, and a UL transmission instruction. And a control unit that controls UL transmission based on the base station, wherein the control unit controls whether or not to apply listening to the UL transmission based on a DL signal transmitted in the first cell. .
- the present invention it is possible to suppress a decrease in throughput in a cell (for example, an unlicensed band) to which listening is applied before transmission.
- FIG. 1A is a diagram illustrating a scenario in which CA is applied in a licensed band cell and an unlicensed band cell
- FIG. 1B is a diagram illustrating a scenario in which DC is applied in a licensed band cell and an unlicensed band cell.
- FIG. 8A is a diagram illustrating an example of a table in which the number of UL subframes to which LBT is not applied is defined
- FIG. 8B is a diagram illustrating an example of a UL transmission method after DL LBT.
- FIG. 9A is a diagram illustrating an example of a table in which the subframe type of each subframe is defined
- FIG. 9B and 9C are diagrams illustrating an example of a UL transmission method after DL LBT.
- FIG. 10A is a diagram illustrating an example of a table in which whether or not LBT is applied to UL transmission is defined
- FIG. 10B is a diagram illustrating an example of a UL transmission method after DL LBT.
- FIG. 1 shows an example of an operation mode of a radio communication system (LTE-U) that operates LTE in an unlicensed band.
- LTE-U radio communication system
- CA Carrier Aggregation
- DC Dual Connectivity
- SA Stand-Alone
- FIG. 1A shows a scenario in which carrier aggregation (CA) is applied using a license band and an unlicensed band.
- CA is a technology for integrating a plurality of frequency blocks (also referred to as component carrier (CC), carrier, cell, etc.) to increase the bandwidth.
- CC component carrier
- Each CC has, for example, a maximum bandwidth of 20 MHz, and when a maximum of five CCs are integrated, a wide band of maximum 100 MHz is realized.
- CA may be applied to a cell using a license band (for example, a macro cell and / or a small cell) and a cell using an unlicensed band (for example, a small cell)
- a scheduler of one radio base station controls scheduling of a plurality of CCs. From this, CA may be called CA in a base station (intra-eNB CA).
- the cell using the unlicensed band can be a carrier (for example, TDD carrier) to which both DL transmission and UL transmission can be applied.
- TDD carrier for example, TDD carrier
- FDD and / or TDD can be used.
- the license band and the unlicensed band can be configured to be transmitted and received from one transmission / reception point (for example, a radio base station) (co-located).
- the transmission / reception point for example, LTE / LTE-U base station
- the transmission / reception point can communicate with the user terminal using both the license band and the unlicensed band.
- a configuration (non-co-located) for transmitting and receiving license bands and unlicensed bands from different transmission / reception points for example, RRH (Remote Radio Head) connected to one radio base station and the other radio base station
- RRH Remote Radio Head
- FIG. 1B shows a scenario in which dual connectivity (DC) is applied using a license band and an unlicensed band.
- DC is the same as CA in that a plurality of CCs (or cells) are integrated to widen the bandwidth.
- CA it is assumed that CCs are connected by ideal backhaul and cooperative control with very small delay time is possible, whereas in DC, delay time is between cells. It is assumed that they are connected by non-ideal backhaul that cannot be ignored.
- DC cells are operated by different base stations, and user terminals communicate by connecting to CCs (or cells) of different frequencies operated by different base stations.
- CCs or cells
- a plurality of schedulers are provided independently, and the plurality of schedulers control the scheduling of one or more cells under their jurisdiction.
- DC may be called CA between base stations (inter-eNB CA).
- intra-eNB CA carrier aggregation
- FIG. 1B shows a case where a cell using a license band (for example, a macro cell) and a cell using an unlicensed band (for example, a small cell) apply DC.
- a cell using an unlicensed band can be a carrier (for example, a TDD carrier) to which both DL transmission and UL transmission can be applied.
- FDD and / or TDD can be used.
- a stand-alone in which a cell that operates LTE using an unlicensed band operates alone is applied.
- stand-alone means that communication with a terminal can be realized without applying CA or DC.
- the unlicensed band can be operated with a carrier (for example, a TDD carrier) to which both DL transmission and UL transmission can be applied.
- the license band CC (macro cell) can be used as a primary cell (PCell) and the unlicensed band CC (small cell) can be used as a secondary cell (SCell).
- the primary cell (PCell) is a cell that manages RRC connection and handover when performing CA, and is a cell that requires UL transmission of data, feedback signals, etc. from user terminals. The primary cell is always set for both the upper and lower links.
- the secondary cell (SCell) is another cell that is set in addition to the primary cell when CA is applied.
- a secondary cell can set only a downlink or an uplink, and can also set an up-and-down link simultaneously.
- LAA Licensed LTE
- LAA-U LAA-LTE
- the license band LTE and the unlicensed band LTE cooperate to communicate with the user terminal.
- a transmission point using a license band for example, a radio base station
- a transmission point using an unlicensed band are separated, use a backhaul link (for example, CPRI (Common Public Radio Interface)). It can be a connected configuration.
- CPRI Common Public Radio Interface
- interference between LAA and Wi-Fi, interference between LAA systems, etc. can be avoided. Moreover, even if it is a case where control of the user terminal which can be connected is performed independently for every operator who operates a LAA system, interference can be reduced without grasping
- listening means that a signal exceeding a predetermined level (for example, predetermined power) is transmitted from another transmission point or the like before a transmission point (for example, a radio base station, a user terminal, etc.) transmits a signal. This refers to the operation of detecting / measuring whether or not there is.
- the listening performed by the radio base station and / or user terminal is also called LBT (Listen Before Talk), CCA (Clear Channel Assessment), carrier sense, or the like.
- a transmission point (LTE-U base station and / or user terminal) listens (LBT, CCA) before transmitting an UL signal and / or DL signal in an unlicensed band. Do. If no signal is detected from another system (for example, Wi-Fi) or another LAA transmission point, communication can be performed in an unlicensed band.
- the transmission point determines that the channel is in an idle state (LBT-idle) and performs transmission.
- the channel is idle means that the channel is not occupied by a specific system, and the channel is idle, the channel is clear, the channel is free, and the like.
- the transmission point determines that the channel is busy (LBT-busy) and restricts transmission. For example, if it is determined as a result of the listening that it is LBT-busy, (1) transit to another carrier by DFS (Dynamic Frequency Selection), (2) perform transmission power control (TPC), (3) transmit Such as not performing transmission (stopping transmission or waiting).
- DFS Dynamic Frequency Selection
- TPC transmission power control
- the channel can be used only after performing LBT again and confirming that the channel is free. Note that the method of determining whether the channel is free / busy by LBT is not limited to this.
- LBT LBT transmission instruction
- UL-LBT LBT
- transmission is performed after it is determined that this is possible.
- time overhead for LBT occurs for each UL transmission, and throughput may be reduced. is there.
- DL-LBT DL transmission listening
- DL-idle a period that can be transmitted without performing LBT after listening (in the case of LBT-idle) is also called a burst length (maximum burst length, maximum allowable burst length, maximum burst length, burst period).
- the present inventors use the period during which DL transmission is not performed among the burst periods set for transmission after listening for DL transmission for UL transmission, so that the user terminal can perform UL transmission without applying LBT.
- the user terminal can perform UL without applying UL-LBT after DL transmission (or DL subframe) from the radio base station in a burst period set for transmission after DL-LBT performed by the radio base station. Transmission can be performed (see FIG. 3).
- the user terminal after receiving the DL signal (or DL subframe), the user terminal can be configured to perform UL transmission without applying the LBT within a predetermined period X.
- the predetermined period X is preferably shortened to, for example, about SIFS (Short IFS) defined in the IEEE 802.11 series which is a wireless LAN standard. In IEEE 802.11, SIFS is specified to be 16 ⁇ s or the like.
- the user terminal needs to determine whether or not to apply UL-LBT to each UL transmission. For example, the user terminal determines whether or not the UL transmission timing (UL subframe) indicated by the UL grant corresponds to a burst period in which UL transmission is allowed (whether or not LBT non-application UL transmission is possible). There is a need.
- the user terminal controls UL transmission based on the UL transmission instruction (UL grant) from the radio base station.
- the user terminal needs a predetermined period (usually at least 4 ms) from receiving the UL grant to performing UL transmission. That is, the user terminal performs UL transmission in a subframe at least 4 ms after receiving the UL grant.
- the radio base station can set the DL subframe for transmitting the UL grant and the UL transmission instructed to be transmitted by the UL grant within the same burst period (FIG. 4). reference).
- FIG. 4 shows a case where the maximum burst length set after DL-LBT (LBT-idle) is 10 ms.
- the radio base station transmits the UL grant to the first user terminal (UE # 1) in the DL subframe of subframe # 5- # 7 in the burst period.
- the first user terminal can perform UL transmission without LBT if a subframe after a predetermined period (for example, 4 ms) from the received DL signal (UL grant) is within the burst period.
- a predetermined period for example, 4 ms
- the user terminal needs to perform UL transmission by applying LBT (second user terminal (UE # 2 in FIG. 4)).
- the maximum burst length is a predetermined value (for example, 4 ms) or less
- the DL subframe for transmitting the UL grant and the UL transmission (UL subframe) instructed to transmit by the UL grant are within the same burst period. Cannot be set (see FIG. 5). This is because the timing (subframe) 4 ms after the user terminal receives the UL grant transmitted within the burst period exceeds the burst period. In this case, the user terminal cannot perform UL transmission not applied to LBT.
- the present inventors have transmitted the UL grant from another cell (cross carrier scheduling) to the user terminal for the burst period. It was noted that UL transmission could be instructed within (see FIG. 6). For example, the radio base station can notify the UL transmission instruction of the unlicensed band using the license band to which the user terminal is connected or another unlicensed band.
- the radio base station transmits the UL grant from another cell to the user terminal before the DL-LBT is performed in the unlicensed band or during the DL-LBT. Therefore, whether or not the user terminal can perform UL transmission without LBT depends on the UL transmission timing (or UL subframe) specified by the UL grant and the burst period start timing (DL-LBT result). . More specifically, the radio base station acquires the channel access right of the unlicensed band by the UL transmission timing specified by the UL grant (LBT-idle), and the UL transmission timing is set within the burst period. It's up to you.
- the present inventors use the DL signal transmitted during the burst period in the predetermined cell even if the maximum burst length in the predetermined cell is a predetermined value (for example, 4 ms) or less, It has been found that whether or not LBT is applied to UL transmission is controlled. Thereby, even when the user terminal transmits a UL signal in a cell to which listening is applied, it is possible to appropriately perform UL transmission not applied to LBT and suppress a decrease in throughput.
- a predetermined value for example, 4 ms
- the present inventors use downlink control information (for example, UL grant) instructing UL transmission in an unlicensed band. It has been found that the user terminal is notified of whether or not LBT is applied to UL transmission.
- a predetermined value for example, 4 ms
- a cell to which listening is applied is described as an unlicensed band (unlicensed band CC), and a cell to which listening is not applied is described as a license band (license band CC), but is not limited thereto.
- the present embodiment can be applied to UL transmission of a cell to which listening is applied.
- FBE Framework Based Equipment
- LBE Load Based Equipment
- FBE has a fixed frame period, and as a result of performing carrier sense in a predetermined frame, it transmits if the channel is usable, but if the channel is unusable, it transmits until the carrier sense timing in the next frame. It is a mechanism that waits without doing.
- LBE is a mechanism for extending carrier sense time when a channel is unusable as a result of carrier sense and continuously performing carrier sense until the channel becomes usable.
- a user terminal determines a channel access method (for example, whether or not LBT is applied) for UL transmission based on whether or not a DL signal transmitted in a burst period is detected (Implicit indication).
- a channel access method for example, whether or not LBT is applied
- Implicit indication a case where the maximum burst length (burst period) in a predetermined cell is 4 ms will be described as an example, but the applicable maximum burst length is not limited to this.
- FIG. 7 shows that the burst period set for transmission after DL-LBT (LTB-idle) is 4 ms, and the radio base station performs DL signals in two subframes (subframes # 1 and # 2) after DL-LBT. Is shown.
- the user terminal can perform UL transmission without applying LBT in a period after DL transmission (here, subframes # 3 and # 4).
- the user terminal performs an operation of detecting a DL signal transmitted from the radio base station in the unlicensed band, and a subframe in which UL transmission is instructed is included in the burst period, and one or more continuous UL sub If it can be determined that the DL transmission continues immediately before the frame, it is determined that the UL transmission not applicable to the LBT is possible. In this way, each user terminal confirms that the DL signal has been transmitted up to the subframe before the UL transmission timing (UL subframe) and controls the UL transmission, so that other systems or the like can control the LBT-idle. It is possible to suppress the occurrence of a collision caused by determining and starting transmission.
- Information on the maximum burst length may be notified to the user terminal in advance by upper layer signaling (for example, RRC signaling) or may be defined in advance by specifications. Further, the user terminal can grasp the UL transmission timing (UL transmission subframe) based on the UL grant transmitted from the radio base station.
- the user terminal can perform LBT for UL transmission based on the information on the maximum burst length, the UL transmission timing specified by the UL grant transmitted from the radio base station, and whether or not the DL signal is detected in the unlicensed band. Applicability can be controlled.
- the radio base station can transmit downlink control information including the UL grant to the user terminal using another cell (for example, a license band) (cross carrier scheduling).
- the first user terminal (UE # 1) and the second user terminal (UE # 2) have the maximum after DL-LBT based on the notification (or predefined information) by higher layer signaling.
- the burst length (here, 4 ms) is grasped.
- UE # 1 is instructed to transmit UL of the unlicensed band in subframes # 3, # 4, and # 5, and UE # 2 is instructed to transmit UL in the unlicensed band in subframe # 5.
- Subframes # 3 and # 4 correspond to subframes within the burst period
- subframe # 5 corresponds to a subframe outside the burst period.
- User terminal (UE # 1, UE # 2) detects DL signal of unlicensed band (for example, serving LAA SCell) after receiving UL grant until the timing of UL subframe indicated by the UL grant Perform the action. If the number of DL subframes detected immediately before the designated UL subframe and the sum of the designated UL subframes do not exceed the maximum burst length, the user terminal determines that UL transmission without LBT is possible. To do.
- DL signal of unlicensed band for example, serving LAA SCell
- UE # 1 performs DL signal detection operation in the license band until the UL subframe timing (in this case, subframe # 3) instructed to be transmitted.
- UE # 1 detects DL signals in subframes # 1 and # 2. Therefore, UE # 1 performs the UL transmission for which transmission has already been instructed using the subframe # 3 without applying the LBT.
- UE # 1 can also perform UL transmission without applying LBT for subframe # 4 as well.
- UE # 1 since UE # 1 can determine that subframe # 5 is outside the burst period based on information on the maximum burst length, UE # 1 performs UL transmission by applying LBT in subframe # 5.
- UE # 2 performs the DL signal detection operation in the license band until the UL subframe timing (here, subframe # 5) instructed to be transmitted.
- the UL subframe timing here, subframe # 5
- UE # 2 since UE # 2 does not detect a DL signal after subframe # 3, it determines that the transmission burst is temporarily interrupted here. Since UE # 2 does not detect a DL signal immediately before subframe # 5 instructed to perform UL transmission, UE # 2 performs UL transmission by applying LBT in subframe # 5.
- the user terminal has at least one of a cell-specific reference signal, downlink control information (DCI) in a common search space (CSS), and downlink control information in a user-specific search space (USS: User-specific Search Space) (combination) Whether or not a DL signal is detected can be determined based on whether or not a signal is detected. Note that the presence or absence of detection of a DL signal may be determined using another DL signal and / or DL channel.
- DCI downlink control information
- CSS common search space
- USS User-specific Search Space
- the user terminal autonomously determines whether or not the LBT for UL transmission is applied based on the detection or non-detection of the DL signal transmitted during the DL-LBT burst period, thereby providing information on whether or not the UL-LBT is applied. Need not be explicitly notified to the user terminal. Thereby, the overhead of DL signal can be reduced.
- the user terminal determines whether or not UL-LBT is applied based on whether or not a DL signal transmitted during the DL-LBT burst period is detected, thereby appropriately determining UL transmission that does not apply to UL-LBT. At the same time, throughput reduction can be suppressed.
- a 2nd aspect demonstrates the case (Explicit indication) when a user terminal judges the channel access method (for example, presence or absence of LBT application) with respect to UL transmission based on the information contained in the DL signal transmitted in a burst period.
- the radio base station can notify the user terminal of the DL signal transmitted in the unlicensed band, including information related to UL transmission listening (UL-LBT). Based on information on whether or not to apply UL-LBT notified from the radio base station, the user terminal applies or does not apply LBT to UL transmission (or UL subframe) subsequent to the subframe in which the DL signal is transmitted. Can be controlled.
- UL-LBT UL transmission listening
- the radio base station can notify the user terminal of an UL transmission instruction in an unlicensed band (for example, LAA SCell) using another cell (for example, a license band).
- the user terminal receives an UL transmission instruction (downlink control information) of the unlicensed band from another cell, and receives information (downlink control information) regarding whether or not LBT is applied to UL transmission in the unlicensed band.
- the UL transmission timing in the unlicensed band is set within the burst period, and the user terminal can appropriately determine whether or not LBT is applied to the UL transmission.
- the radio base station can define and use a new RNTI as an identifier (RNTI: Radio Network Temporary Identifier) associated with downlink control information (DCI) transmitted in an unlicensed band.
- RNTI Radio Network Temporary Identifier
- the radio base station can transmit downlink control information (DCI) including information on whether or not LBT is applied to UL transmission using the newly defined RNTI.
- DCI downlink control information
- the user terminal can perform DCI decoding using the RNTI.
- the radio base station may transmit information on the LBT for UL transmission using an existing DCI format (for example, DCI format 3 / 3A).
- an existing DCI format for example, DCI format 3 / 3A.
- the radio base station can notify the information related to the LBT for UL transmission as the number of UL subframes to which LBT is not applied (for example, the number of consecutive LBT non-applied UL subframes) (notification method 1).
- the radio base station can notify information on the LBT for UL transmission as to whether or not LBT is applied for each subframe using a bitmap (notification method 2). Below, each notification method is demonstrated.
- the radio base station can notify the user terminal of information on the number of UL subframes to which LBT is not applied after the next subframe, using the DL signal (DL subframe).
- the radio base station sets a 2-bit field in downlink control information (DCI), and uses the bit field to inform the user terminal about the number of UL subframes to which LBT is not applied after the next subframe.
- DCI downlink control information
- the user terminal can control UL transmission based on the notified bit information (index) and the corresponding table (see FIG. 8A).
- the table of FIG. 8A indicates that, when the bit field value is “0”, UL transmission not applying LBT is not allowed in the next subframe.
- the user terminal can determine that the next subframe is a DL subframe or an UL subframe to which LBT is applied. Further, the user terminal can determine whether the next subframe is a DL subframe or a UL subframe based on detection of a DL signal and / or presence / absence of a transmission instruction by a UL grant. Even when the DCI cannot be detected, the user terminal may determine that the next subframe is a DL subframe or an UL subframe to which LBT is applied.
- 8A shows the number of UL subframes to which LBT is not applied after the next subframe when the bit field values are “1”, “2”, and “3”. For example, when the value of the bit field is “1”, the user terminal can determine that the next one subframe is a UL subframe to which LBT is not applied. When the value of the bit field is “2”, the user terminal can determine that the next two consecutive subframes are UL subframes to which LBT is not applied. When the value of the bit field is “3”, the user terminal can determine that the next three consecutive subframes are UL subframes to which LBT is not applied.
- the burst period set after DL-LBT (LTB-idle) is 4 ms, and the radio base station transmits a DL signal in two subframes (subframes # 1 and # 2) after DL-LBT. Shows the case. In this case, the user terminal can perform UL transmission without applying LBT in two subframes (subframes # 3 and # 4) after DL transmission.
- the radio base station can transmit by setting “2” in the bit field of the DL signal (eg, downlink control information) of subframe # 2.
- the user terminal determines that the next two consecutive subframes (subframes # 3 and # 4) are subframes in which UL transmission not applicable to LBT is allowed, and performs UL transmission.
- the first user terminal (UE # 1) instructed to transmit UL for subframes # 3, # 4, and # 5 applies LBT to subframes # 3 and # 4 based on the received DL signal. Without performing UL transmission.
- UE # 1 performs UL transmission by applying LBT to subframe # 5.
- the radio base station transmits bit information (for example, the number of UL subframes not applicable to UL-LBT) related to the UL transmission LBT to all DL subframes (subframes # 1 and # 2 in FIG. 8B). Can be included.
- the radio base station may set “0” in the bit field of the DL signal of subframe # 1.
- the user terminal instructed to perform UL transmission can operate to perform UL transmission to which LBT is applied.
- the radio base station can include bit information regarding the number of UL subframes to which UL-LBT is not applied only in some DL subframes (subframe # 2 in FIG. 8B) in the unlicensed band.
- Some DL subframes may be subframes in which the next subframe becomes a UL subframe (a subframe immediately before the UL subframe).
- FIG. 8A shows the case where the bit field is 2 bits, the present embodiment is not limited to this.
- the number of bits in the bit field can be appropriately set based on the maximum burst length or the like.
- the radio base station can notify the user terminal of information on whether or not UL-LBT is applied to each subframe after the next subframe, using an unlicensed band DL signal.
- the radio base station sets a 4-bit bitmap in the downlink control information, and uses the 4-bit bitmap to set the subframe type (UL channel access method) of each subframe after the next subframe.
- the user terminal can control whether or not LBT is applied to UL transmission based on the notified bit map information (“0” or “1”) and the corresponding table (see FIG. 9A).
- a bitmap value “0” indicates that the corresponding subframe is a DL subframe or a UL subframe to which LBT is applied.
- the user terminal can control the UL transmission by determining that the corresponding subframe is a DL subframe or a UL subframe to which LBT is applied.
- the bitmap value “1” indicates that the corresponding subframe is a UL subframe to which LBT is not applied.
- the user terminal can control the UL transmission by determining that the corresponding subframe is a UL subframe to which the LBT is not applied.
- the radio base station can include the bitmap in a DL signal (or DL subframe) that is transmitted first in the burst period of the unlicensed band (see FIG. 9B).
- FIG. 9B shows a case where the burst period of DL-LBT (LTB-idle) is 4 ms, and the radio base station transmits a DL signal in two subframes (subframes # 1 and # 2) after the DL-LBT. ing.
- the radio base station can notify the user terminal by including a 4-bit bitmap of “0, 1, 1, 0” in the DL signal of subframe # 1.
- the 4-bit bitmap corresponds to subframes # 2- # 5 in order.
- the user terminal can control the UL transmission by determining the subframe type after subframe # 2 based on the bitmap.
- the radio base station can include the bitmap in only some DL subframes in the unlicensed band (see FIG. 9C).
- Some DL subframes can be subframes (subframe # 2 in FIG. 9C) in which the next subframe is a UL subframe.
- the radio base station can notify the user terminal by including a 4-bit bitmap of “1, 1, 0, 0” in the DL signal of subframe # 2.
- the 4-bit bitmap corresponds to subframes # 3- # 6 in order.
- the user terminal can control the UL transmission by determining the subframe type after subframe # 3 based on the bitmap.
- the radio base station may notify the user terminal by including the bitmap in each DL subframe in the unlicensed band.
- FIG. 9 shows the case where the bitmap is 4 bits, the present embodiment is not limited to this.
- the number of bits to be applied to the bitmap can be appropriately set based on the maximum burst length or the like.
- the user terminal appropriately determines whether or not UL-LBT is applied based on the information included in the DL signal transmitted during the DL-LBT burst period, thereby appropriately performing UL transmission not applying UL-LBT. At the same time, throughput reduction can be suppressed.
- a user terminal determines a channel access method (for example, whether or not LBT is applied) for UL transmission based on UL grant included in a DL signal transmitted in a burst period (Implicit indication).
- the third aspect can be suitably applied when the maximum burst length in a predetermined cell is longer than a predetermined value (for example, 4 ms).
- the radio base station grasps whether the UL transmission (UL subframe) indicated by the UL grant is included in the burst period at the time of transmitting the UL grant. Can do. In this case, the radio base station can instruct the user terminal about the UL channel access method (whether or not UL-LBT is applied) when transmitting the UL grant.
- the radio base station sets a bit field (for example, 1 bit) in downlink control information (UL grant) instructing UL transmission in an unlicensed band, and applies LBT to the UL transmission in addition to the UL transmission instruction.
- the presence or absence can also be notified. Or you may notify the user terminal of the information regarding the presence or absence of application of LBT with respect to UL transmission using the predetermined
- the user terminal can control UL transmission based on bit information notified by downlink control information (for example, UL grant) and a corresponding table (see FIG. 10A).
- the burst period set after DL-LBT (LTB-idle) is 10 ms, and the radio base station transmits a DL signal in 7 subframes (subframes # 1 to # 7) after DL-LBT.
- the user terminal can perform UL transmission without applying LBT in a period after DL transmission (here, subframe # 8 to # 10).
- UL transmission in the unlicensed band is instructed to the first user terminal (UE # 1) using downlink control information of DL subframes # 4- # 6 in the burst period.
- the second user terminal (UE # 2) is instructed to perform UL transmission in the unlicensed band using the downlink control information of DL subframe # 7 in the burst period.
- the radio base station can grasp whether the UL transmission (for example, after 4 ms) indicated by the UL grant is included in the burst period. Accordingly, the radio base station notifies the user terminal of the downlink control information (UL grant) including information on whether or not LBT is applied to UL transmission.
- the radio base station notifies UE # 1 including information (“1” in FIG. 10A) that is UL transmission not applied to the LBT in the downlink control information of DL subframes # 4- # 6. To do. Based on the received UL grant, UE # 1 performs UL transmission not applying LBT in UL subframes # 8 to # 10. Also, the radio base station notifies UE # 2 of the DL control information of DL subframe # 7 including information (“0” in FIG. 10A) that is LBT-applied UL transmission. Based on the received UL grant, UE # 2 performs UL transmission not applied to LBT in UL subframe # 11.
- FIG. 10B shows the case where the radio base station transmits a UL transmission instruction in the unlicensed band using the DL of the unlicensed band, but this embodiment is not limited to this.
- the radio base station can also notify the user terminal of an UL transmission instruction in the unlicensed band using another cell (for example, a license band).
- another cell for example, a license band.
- the user terminal may determine that LBT is applied to UL transmission and control transmission.
- the user terminal appropriately performs LBT non-application UL transmission by controlling the application of LBT to UL transmission based on the UL grant associated with the UL-LBT application information, and the throughput. It is possible to suppress the decrease.
- FIG. 11 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment of the present invention.
- the radio communication system shown in FIG. 11 is a system including, for example, an LTE system, SUPER 3G, LTE-A system, and the like.
- carrier aggregation (CA) and / or dual connectivity (DC) in which a plurality of component carriers (CC) are integrated can be applied.
- the plurality of CCs include a license band CC that uses a license band and an unlicensed band CC that uses an unlicensed band.
- This wireless communication system may be called IMT-Advanced, or may be called 4G, 5G, FRA (Future Radio Access), or the like.
- a radio communication system 1 shown in FIG. 11 includes a radio base station 11 that forms a macro cell C1, a radio base station 12 (12a-12c) that is arranged in the macro cell C1 and forms a small cell C2 narrower than the macro cell C1, It has. Moreover, the user terminal 20 is arrange
- the user terminal 20 can be connected to both the radio base station 11 and the radio base station 12. It is assumed that the user terminal 20 uses the macro cell C1 and the small cell C2 that use different frequencies simultaneously by CA or DC. Further, the user terminal 20 can apply CA using at least 2 CCs (cells), and can also use 6 or more CCs.
- Communication between the user terminal 20 and the radio base station 11 can be performed using a carrier having a relatively low frequency band (for example, 2 GHz) and a narrow bandwidth (referred to as an existing carrier or a legacy carrier).
- a carrier having a relatively high frequency band for example, 3.5 GHz, 5 GHz, etc.
- a wide bandwidth may be used between the user terminal 20 and the radio base station 12, or The same carrier may be used.
- a wired connection optical fiber, X2 interface, etc.
- a wireless connection may be employed between the wireless base station 11 and the wireless base station 12 (or between the two wireless base stations 12).
- the radio base station 11 and each radio base station 12 are connected to the higher station apparatus 30 and connected to the core network 40 via the higher station apparatus 30.
- the upper station device 30 includes, for example, an access gateway device, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto.
- RNC radio network controller
- MME mobility management entity
- Each radio base station 12 may be connected to the higher station apparatus 30 via the radio base station 11.
- the radio base station 11 is a radio base station having a relatively wide coverage, and may be called a macro base station, an aggregation node, an eNB (eNodeB), a transmission / reception point, or the like.
- the radio base station 12 is a radio base station having local coverage, and includes a small base station, a micro base station, a pico base station, a femto base station, a HeNB (Home eNodeB), an RRH (Remote Radio Head), and transmission / reception. It may be called a point.
- the radio base stations 11 and 12 are not distinguished, they are collectively referred to as a radio base station 10.
- Each user terminal 20 is a terminal that supports various communication schemes such as LTE and LTE-A, and may include not only a mobile communication terminal but also a fixed communication terminal.
- OFDMA Orthogonal Frequency Division Multiple Access
- SC-FDMA Single Carrier Frequency Division Multiple Access
- OFDMA is a multi-carrier transmission scheme that performs communication by dividing a frequency band into a plurality of narrow frequency bands (subcarriers) and mapping data to each subcarrier.
- SC-FDMA is a single-carrier transmission scheme that reduces interference between terminals by dividing the system bandwidth into bands consisting of one or continuous resource blocks for each terminal and using a plurality of terminals with mutually different bands. is there.
- the uplink and downlink radio access methods are not limited to these combinations.
- downlink channels include a downlink shared channel (PDSCH) shared by each user terminal 20, a broadcast channel (PBCH: Physical Broadcast Channel), a downlink L1 / L2 control channel, and the like. Used. User data, higher layer control information, and predetermined SIB (System Information Block) are transmitted by PDSCH. Moreover, MIB (Master Information Block) etc. are transmitted by PBCH.
- PDSCH downlink shared channel
- PBCH Physical Broadcast Channel
- SIB System Information Block
- MIB Master Information Block
- Downlink L1 / L2 control channels include PDCCH (Physical Downlink Control Channel), EPDCCH (Enhanced Physical Downlink Control Channel), PCFICH (Physical Control Format Indicator Channel), PHICH (Physical Hybrid-ARQ Indicator Channel), and the like.
- Downlink control information (DCI: Downlink Control Information) including scheduling information of PDSCH and PUSCH is transmitted by PDCCH.
- the number of OFDM symbols used for PDCCH is transmitted by PCFICH.
- the HAICH transmission confirmation signal (ACK / NACK) for PUSCH is transmitted by PHICH.
- the EPDCCH is frequency division multiplexed with a PDSCH (downlink shared data channel) and may be used to transmit DCI or the like in the same manner as the PDCCH.
- a downlink reference signal a cell-specific reference signal (CRS), a channel state measurement reference signal (CSI-RS), a user-specific reference signal used for demodulation includes reference signals (DM-RS: Demodulation Reference Signal).
- CRS cell-specific reference signal
- CSI-RS channel state measurement reference signal
- DM-RS Demodulation Reference Signal
- an uplink shared channel (PUSCH: Physical Uplink Shared Channel), an uplink control channel (PUCCH: Physical Uplink Control Channel), and a random access channel (PRACH) shared by each user terminal 20 are used. Physical Random Access Channel) is used. User data and higher layer control information are transmitted by PUSCH. Also, downlink radio quality information (CQI: Channel Quality Indicator), a delivery confirmation signal (HARQ-ACK), and the like are transmitted by PUCCH.
- CQI Channel Quality Indicator
- HARQ-ACK delivery confirmation signal
- a random access preamble (RA preamble) for establishing a connection with the cell is transmitted by the PRACH.
- FIG. 12 is a diagram illustrating an example of the overall configuration of a radio base station according to an embodiment of the present invention.
- the radio base station 10 includes a plurality of transmission / reception antennas 101, an amplifier unit 102, a transmission / reception unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106.
- the transmission / reception unit 103 includes a transmission unit and a reception unit.
- User data transmitted from the radio base station 10 to the user terminal 20 via the downlink is input from the higher station apparatus 30 to the baseband signal processing unit 104 via the transmission path interface 106.
- PDCP Packet Data Convergence Protocol
- RLC Radio Link Control
- MAC Medium Access
- Retransmission control for example, transmission processing of HARQ (Hybrid Automatic Repeat reQuest)
- HARQ Hybrid Automatic Repeat reQuest
- IFFT inverse Fast Fourier Transform
- precoding processing etc.
- the downlink control signal is also subjected to transmission processing such as channel coding and inverse fast Fourier transform, and transferred to each transmitting / receiving unit 103.
- Each transmission / reception unit 103 converts the baseband signal output by precoding from the baseband signal processing unit 104 for each antenna to a radio frequency band and transmits the converted signal.
- the radio frequency signal frequency-converted by the transmission / reception unit 103 is amplified by the amplifier unit 102 and transmitted from the transmission / reception antenna 101.
- the transmission / reception unit (transmission unit) 103 transmits downlink control information (for example, UL grant) instructing UL transmission in the unlicensed band.
- the transmission / reception part 103 can transmit the information regarding maximum burst length to a user terminal using higher layer signaling (for example, RRC signaling, a broadcast signal, etc.).
- the transmission / reception unit 103 can transmit the DL signal in the unlicensed band when the DL-LBT result performed before transmitting the DL signal is LBT-idle.
- the transmission / reception unit 103 can be a transmitter / receiver, a transmission / reception circuit, or a transmission / reception device described based on common recognition in the technical field according to the present invention.
- the radio frequency signal received by each transmitting / receiving antenna 101 is amplified by the amplifier unit 102.
- Each transmitting / receiving unit 103 receives the upstream signal amplified by the amplifier unit 102.
- the transmission / reception unit 103 converts the frequency of the received signal into a baseband signal and outputs it to the baseband signal processing unit 104.
- the baseband signal processing unit 104 performs fast Fourier transform (FFT) processing, inverse discrete Fourier transform (IDFT: Inverse Discrete Fourier Transform) processing, and error correction on user data included in the input upstream signal.
- FFT fast Fourier transform
- IDFT inverse discrete Fourier transform
- Decoding, MAC retransmission control reception processing, RLC layer, and PDCP layer reception processing are performed and transferred to the upper station apparatus 30 via the transmission path interface 106.
- the call processing unit 105 performs call processing such as communication channel setting and release, status management of the radio base station 10, and radio resource management.
- the transmission path interface 106 transmits and receives signals to and from the higher station apparatus 30 via a predetermined interface.
- the transmission path interface 106 may transmit and receive signals (backhaul signaling) to and from the adjacent radio base station 10 via an inter-base station interface (for example, an optical fiber or an X2 interface).
- FIG. 13 is a diagram illustrating an example of a functional configuration of the radio base station according to the present embodiment. Note that FIG. 13 mainly shows functional blocks of characteristic portions in the present embodiment, and the wireless base station 10 also has other functional blocks necessary for wireless communication.
- the baseband signal processing unit 104 includes a control unit (scheduler) 301, a transmission signal generation unit (generation unit) 302, a mapping unit 303, a reception signal processing unit 304, a measurement unit 305, It is equipped with.
- the control unit (scheduler) 301 controls scheduling (for example, resource allocation) of downlink data transmitted on the PDSCH, downlink control information transmitted on the PDCCH and / or EPDCCH. It also controls scheduling of system information, synchronization signals, paging information, CRS, CSI-RS, and the like.
- the control unit 301 controls scheduling of an uplink reference signal, an uplink data signal transmitted by PUSCH, an uplink control signal transmitted by PUCCH and / or PUSCH, a random access preamble transmitted by PRACH, and the like.
- the control unit 301 can control to transmit an UL transmission (for example, PUSCH transmission) instruction in an unlicensed band using downlink control information of another cell (cross carrier scheduling).
- the control unit 301 can be a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present invention.
- the transmission signal generation unit 302 generates a DL signal based on an instruction from the control unit 301 and outputs the DL signal to the mapping unit 303. For example, based on an instruction from the control unit 301, the transmission signal generation unit 302 generates a DL assignment that notifies downlink signal allocation information and a UL grant that notifies uplink signal allocation information. Further, the transmission signal generation unit 302 can include information on the LBT for UL transmission in the DL signal transmitted in the unlicensed band. In addition, the transmission signal generation unit 302 can include information on whether UL-LBT is applied or not in the UL grant.
- the transmission signal generation unit 302 can be a signal generator, a signal generation circuit, or a signal generation device described based on common recognition in the technical field according to the present invention.
- the mapping unit 303 maps the downlink signal generated by the transmission signal generation unit 302 to a predetermined radio resource based on an instruction from the control unit 301, and outputs it to the transmission / reception unit 103.
- the mapping unit 303 can be a mapper, a mapping circuit, or a mapping device described based on common recognition in the technical field according to the present invention.
- the reception signal processing unit 304 performs reception processing (for example, demapping, demodulation, demodulation) on UL signals (for example, a delivery confirmation signal (HARQ-ACK), a data signal transmitted by PUSCH, etc.) transmitted from the user terminal. Decryption, etc.).
- the processing result is output to the control unit 301.
- the reception signal processing unit 304 can be configured by a signal processor, a signal processing circuit, or a signal processing device described based on common recognition in the technical field according to the present invention.
- the measurement unit 305 can measure received power (for example, RSRP (Reference Signal Received Power)), reception quality (RSRQ (Reference Signal Received Quality)), channel state, and the like using the received signal.
- the measurement unit 305 can measure the received power of a signal transmitted from another system or the like in listening performed before transmitting a DL signal in an unlicensed band.
- the result measured by the measurement unit 305 is output to the control unit 301.
- the control unit 301 can control the transmission of the DL signal based on the measurement result (listening result) of the measurement unit 305.
- the measuring unit 305 can be composed of a measuring device, a measuring circuit, or a measuring device described based on common recognition in the technical field according to the present invention.
- FIG. 14 is a diagram illustrating an example of the overall configuration of the user terminal according to the present embodiment.
- the user terminal 20 includes a plurality of transmission / reception antennas 201 for MIMO transmission, an amplifier unit 202, a transmission / reception unit 203, a baseband signal processing unit 204, and an application unit 205.
- the transmission / reception unit 203 may include a transmission unit and a reception unit.
- the radio frequency signals received by the plurality of transmission / reception antennas 201 are each amplified by the amplifier unit 202.
- Each transmitting / receiving unit 203 receives the downlink signal amplified by the amplifier unit 202.
- the transmission / reception unit 203 converts the frequency of the received signal into a baseband signal and outputs it to the baseband signal processing unit 204.
- the transmission / reception unit (reception unit) 203 can receive a DL signal (for example, UL grant) instructing UL transmission in the unlicensed band.
- the transmission / reception unit 203 can receive information on the maximum burst length set for transmission after DL-LBT.
- the transmission / reception unit 203 can receive a DL signal including information related to listening for UL transmission.
- the transmission / reception unit 203 can receive information related to listening for UL transmission using a predetermined bit field or bitmap of downlink control information transmitted in the unlicensed band.
- the transmission / reception unit 203 can be a transmitter / receiver, a transmission / reception circuit, or a transmission / reception device described based on common recognition in the technical field according to the present invention.
- the baseband signal processing unit 204 performs FFT processing, error correction decoding, retransmission control reception processing, and the like on the input baseband signal.
- the downlink user data is transferred to the application unit 205.
- the application unit 205 performs processing related to layers higher than the physical layer and the MAC layer.
- broadcast information in the downlink data is also transferred to the application unit 205.
- uplink user data is input from the application unit 205 to the baseband signal processing unit 204.
- the baseband signal processing unit 204 performs retransmission control transmission processing (for example, HARQ transmission processing), channel coding, precoding, discrete Fourier transform (DFT) processing, IFFT processing, and the like.
- the data is transferred to the transmission / reception unit 203.
- the transmission / reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band and transmits it.
- the radio frequency signal frequency-converted by the transmission / reception unit 203 is amplified by the amplifier unit 202 and transmitted from the transmission / reception antenna 201.
- FIG. 15 is a diagram illustrating an example of a functional configuration of the user terminal according to the present embodiment. Note that FIG. 15 mainly shows functional blocks of characteristic portions in the present embodiment, and the user terminal 20 also has other functional blocks necessary for wireless communication. As illustrated in FIG. 15, the baseband signal processing unit 204 included in the user terminal 20 includes a control unit 401, a transmission signal generation unit 402, a mapping unit 403, a reception signal processing unit 404, and a measurement unit 405. I have.
- the control unit 401 can control the transmission signal generation unit 402, the mapping unit 403, and the reception signal processing unit 404. For example, the control unit 401 obtains, from the reception signal processing unit 404, a downlink control signal (signal transmitted by PDCCH / EPDCCH) and a downlink data signal (signal transmitted by PDSCH) transmitted from the radio base station 10. .
- the control unit 401 generates / transmits uplink control signals (for example, HARQ-ACK) and uplink data based on downlink control information (UL grant), a result of determining whether retransmission control is required for downlink data, and the like (for example, HARQ-ACK). (UL transmission) is controlled.
- control unit 401 can control whether to apply listening for UL transmission in the unlicensed band based on a DL signal transmitted after listening for DL transmission in the unlicensed band.
- the control unit 401 determines the UL based on the information regarding the burst period set after the DL-LBT in the unlicensed band, the presence / absence of detection of the DL signal in the unlicensed band, and the UL transmission timing based on the UL transmission instruction. It is possible to control whether or not listening is applied to transmission. Specifically, in a burst period set after DL-LBT of the unlicensed band, a subframe in which UL transmission is instructed is included in the burst period, and immediately before one or more consecutive UL subframes. When it can be determined that the DL transmission continues, the UL transmission can be performed without applying the listening.
- control unit 401 can control whether or not to apply listening for UL transmission based on information related to UL transmission listening included in a DL signal transmitted in an unlicensed band.
- the information regarding the listening for UL transmission is information regarding whether or not the UL subframe to which the listening for UL transmission is not applied after the next subframe of the subframe that has received the DL signal including the information regarding the listening. It can be set as the structure containing.
- control unit 401 can control whether or not to apply listening to UL transmission based on information related to listening for UL transmission included in the UL transmission instruction.
- control part 401 can control UL transmission in consideration of the measurement result (for example, received power from other systems etc.) output from the measurement part 405.
- the control unit 401 may be a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present invention.
- the transmission signal generation unit 402 generates a UL signal based on an instruction from the control unit 401 and outputs the UL signal to the mapping unit 403. For example, the transmission signal generation unit 402 generates an uplink control signal such as a delivery confirmation signal (HARQ-ACK) or channel state information (CSI) corresponding to the DL signal based on an instruction from the control unit 401.
- HARQ-ACK delivery confirmation signal
- CSI channel state information
- the transmission signal generation unit 402 generates an uplink data signal based on an instruction from the control unit 401. For example, the transmission signal generation unit 402 is instructed by the control unit 401 to generate an uplink data signal when the UL grant is included in the downlink control signal notified from the radio base station 10.
- the transmission signal generation unit 402 may be a signal generator, a signal generation circuit, or a signal generation device described based on common recognition in the technical field according to the present invention.
- the mapping unit 403 maps the uplink signal (uplink control signal and / or uplink data) generated by the transmission signal generation unit 402 to a radio resource based on an instruction from the control unit 401, and outputs the radio resource to the transmission / reception unit 203.
- the mapping unit 403 may be a mapper, a mapping circuit, or a mapping device described based on common recognition in the technical field according to the present invention.
- the reception signal processing unit 404 performs reception processing (for example, demapping and demodulation) on a DL signal (for example, a downlink control signal transmitted from a radio base station using PDCCH / EPDCCH, a downlink data signal transmitted using PDSCH, etc.). , Decryption, etc.).
- the reception signal processing unit 404 outputs information received from the radio base station 10 to the control unit 401 and the measurement unit 405.
- the reception signal processing unit 404 can be configured by a signal processor, a signal processing circuit, or a signal processing device described based on common recognition in the technical field according to the present invention. Further, the reception signal processing unit 404 can constitute a reception unit according to the present invention.
- the measurement unit 405 may measure received power (for example, RSRP (Reference Signal Received Power)), reception quality (RSRQ (Reference Signal Received Quality)), channel state, and the like using the received signal.
- the measurement unit 405 can measure the received power of a signal transmitted from another system or the like in listening performed before transmission of the UL signal in the unlicensed band.
- the result measured by the measurement unit 405 is output to the control unit 401.
- the control unit 401 can control transmission of the UL signal based on the measurement result (listening result) of the measurement unit 405.
- the measuring unit 405 can be composed of a measuring instrument, a measuring circuit, or a measuring device described based on common recognition in the technical field according to the present invention.
- each functional block is realized by one physically coupled device, or may be realized by two or more physically separated devices connected by wire or wirelessly and by a plurality of these devices. Good.
- the radio base station 10 and the user terminal 20 are realized using hardware such as ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), and FPGA (Field Programmable Gate Array). May be.
- the radio base station 10 and the user terminal 20 are each a computer device including a processor (CPU: Central Processing Unit), a communication interface for network connection, a memory, and a computer-readable storage medium holding a program. It may be realized. That is, the radio base station, user terminal, and the like according to an embodiment of the present invention may function as a computer that performs processing of the radio communication method according to the present invention.
- Computer-readable recording media include, for example, flexible disks, magneto-optical disks, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), CD-ROM (Compact Disc-ROM), RAM (Random Access Memory), A storage medium such as a hard disk.
- the program may be transmitted from a network via a telecommunication line.
- the radio base station 10 and the user terminal 20 may include an input device such as an input key and an output device such as a display.
- the functional configurations of the radio base station 10 and the user terminal 20 may be realized by the hardware described above, may be realized by a software module executed by a processor, or may be realized by a combination of both.
- the processor controls the entire user terminal by operating an operating system. Further, the processor reads programs, software modules and data from the storage medium into the memory, and executes various processes according to these.
- the program may be a program that causes a computer to execute the operations described in the above embodiments.
- the control unit 401 of the user terminal 20 may be realized by a control program stored in a memory and operated by a processor, and may be realized similarly for other functional blocks.
- software, instructions, etc. may be transmitted / received via a transmission medium.
- software may use websites, servers, or other devices using wired technology such as coaxial cable, fiber optic cable, twisted pair and digital subscriber line (DSL) and / or wireless technology such as infrared, wireless and microwave.
- wired technology such as coaxial cable, fiber optic cable, twisted pair and digital subscriber line (DSL) and / or wireless technology such as infrared, wireless and microwave.
- DSL digital subscriber line
- wireless technology such as infrared, wireless and microwave.
- the channel and / or symbol may be a signal (signaling).
- the signal may be a message.
- the component carrier (CC) may be called a carrier frequency, a cell, or the like.
- information, parameters, and the like described in this specification may be represented by absolute values, may be represented by relative values from a predetermined value, or may be represented by other corresponding information.
- the radio resource may be indicated by an index.
- notification of predetermined information is not limited to explicitly performed, but is performed implicitly (for example, notification of the predetermined information is not performed). Also good.
- notification of information is not limited to the aspect / embodiment described in this specification, and may be performed by other methods.
- notification of information includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), It may be implemented by broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof.
- the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC connection setup (RRCConnectionSetup) message, an RRC connection reconfiguration (RRCConnectionReconfiguration) message, or the like.
- Each aspect / embodiment described in this specification includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio Access), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other appropriate systems
- LTE Long Term Evolution
- LTE-A LTE-Advanced
- SUPER 3G IMT-Advanced
- 4G 5G
- FRA Full Radio Access
- CDMA2000 Code Division Multiple Access 2000
- UMB User Mobile Broadband
- IEEE 802.11 Wi-Fi
- IEEE 802.16 WiMAX
- IEEE 802.20 UWB (Ultra-WideBand)
- Bluetooth registered trademark
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
第1の態様では、ユーザ端末がUL送信に対するチャネルアクセス方法(例えば、LBT適用有無)を、バースト期間に送信されるDL信号の検出有無に基づいて判断する場合(Implicit indication)について説明する。なお、以下の説明では、所定セルにおける最大バースト長(バースト期間)が4msの場合を例に挙げて説明するが、適用可能な最大バースト長はこれに限られない。
第2の態様では、ユーザ端末がUL送信に対するチャネルアクセス方法(例えば、LBT適用有無)を、バースト期間に送信されるDL信号に含まれる情報に基づいて判断する場合(Explicit indication)について説明する。
無線基地局は、DL信号(DLサブフレーム)を用いて、次サブフレーム以降にLBT非適用となるULサブフレーム数に関する情報をユーザ端末に通知することができる。一例として、無線基地局は、下り制御情報(DCI)に2ビットのフィールドを設定し、当該ビットフィールドを用いて、次サブフレーム以降にLBT非適用となるULサブフレーム数に関する情報をユーザ端末に通知する。ユーザ端末は、通知されたビット情報(インデックス)と、対応するテーブルに基づいて、UL送信を制御することができる(図8A参照)。
無線基地局は、アンライセンスバンドのDL信号を用いて、次サブフレーム以降の各サブフレームに対するUL-LBT適用有無に関する情報をユーザ端末に通知することができる。一例として、無線基地局は、下り制御情報に4ビットのビットマップを設定し、当該4ビットのビットマップを用いて、次サブフレーム以降の各サブフレームのサブフレームタイプ(ULチャネルアクセス方式)を通知する。ユーザ端末は、通知されたビットマップ情報(“0”又は“1”)と対応するテーブルに基づいて、UL送信に対するLBT適用有無を制御することができる(図9A参照)。
第3の態様では、ユーザ端末がUL送信に対するチャネルアクセス方法(例えば、LBT適用有無)を、バースト期間に送信されるDL信号に含まれるULグラントに基づいて判断する場合(Implicit indication)について説明する。なお、第3の態様は、所定セルにおける最大バースト長が所定値(例えば、4ms)より長い場合に好適に適用することができる。
以下、本発明の一実施形態に係る無線通信システムの構成について説明する。この無線通信システムでは、本発明の実施形態に係る無線通信方法が適用される。なお、上記の各実施の態様に係る無線通信方法は、それぞれ単独で適用されてもよいし、組み合わせて適用してもよい。
図12は、本発明の一実施形態に係る無線基地局の全体構成の一例を示す図である。無線基地局10は、複数の送受信アンテナ101と、アンプ部102と、送受信部103と、ベースバンド信号処理部104と、呼処理部105と、伝送路インターフェース106と、を備えている。なお、送受信部103は、送信部及び受信部で構成される。
図14は、本実施形態に係るユーザ端末の全体構成の一例を示す図である。ユーザ端末20は、MIMO伝送のための複数の送受信アンテナ201と、アンプ部202と、送受信部203と、ベースバンド信号処理部204と、アプリケーション部205と、を備えている。なお、送受信部203は、送信部及び受信部から構成されてもよい。
Claims (10)
- 信号の送信前にリスニングを適用する第1のセルを少なくとも用いて通信を行うユーザ端末であって、
UL送信指示を含むDL信号を受信する受信部と、
UL送信指示に基づいてUL送信を制御する制御部と、を有し、
前記制御部は、第1のセルで送信されるDL信号に基づいて、UL送信に対するリスニングの適用有無を制御することを特徴とするユーザ端末。 - 前記制御部は、第1のセルでDL送信用のリスニング後に設定されるバースト期間に関する情報と、第1のセルにおけるDL信号の検出有無と、UL送信指示に基づくUL送信タイミングと、に基づいて、UL送信に対するリスニングの適用有無を制御することを特徴とする請求項1に記載のユーザ端末。
- 前記制御部は、UL送信のサブフレームが第1のセルのDL送信用のリスニング後に設定されるバースト期間内に含まれ、当該UL送信のサブフレームの前のサブフレームまでDL信号が送信されている場合に、リスニングを適用せずにUL送信を行うことを特徴とする請求項2に記載のユーザ端末。
- 前記制御部は、第1のセルで送信されるDL信号に含まれるUL送信用のリスニングに関する情報に基づいて、UL送信に対するリスニングの適用有無を制御することを特徴とする請求項1に記載のユーザ端末。
- 前記UL送信用のリスニングに関する情報は、リスニングに関する情報が含まれるDL信号を受信したサブフレームの次サブフレーム以降において、UL送信用のリスニングを適用しないULサブフレームであるか否かに関する情報を含むことを特徴とする請求項4に記載のユーザ端末。
- 前記受信部は、前記UL送信用のリスニングに関する情報を、第1のセルで送信される下り制御情報の所定のビットフィールド、又はビットマップにより受信することを特徴とする請求項5に記載のユーザ端末。
- 前記受信部は、第1のセルにおけるUL送信指示を含むDL信号を、第1のセルと異なる第2のセルで受信することを特徴とする請求項1から請求項6のいずれかに記載のユーザ端末。
- 前記制御部は、UL送信指示に含まれるUL送信用のリスニングに関する情報に基づいて、UL送信に対するリスニングの適用有無を制御することを特徴とする請求項1に記載のユーザ端末。
- 信号の送信前にリスニングを適用する第1のセルを少なくとも用いてユーザ端末と通信を行う無線基地局であって、
UL送信指示を含むDL信号を送信する送信部と、
UL送信指示に基づいてユーザ端末が送信するUL信号を受信する受信部と、を有し、
前記送信部は、第1のセルでDL送信用のリスニング後に設定されるバースト期間に、UL送信用のリスニングの適用有無に関する情報を含むDL信号を送信することを特徴とする無線基地局。 - 信号の送信前にリスニングを適用する第1のセルを少なくとも用いて通信を行うユーザ端末の無線通信方法であって、
UL送信指示を含むDL信号を受信する工程と、
UL送信指示に基づいてUL信号を送信する工程と、を有し、
第1のセルで送信されるDL信号に基づいて、UL信号の送信に対するリスニングの適用有無を制御することを特徴とする無線通信方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15/578,788 US20180302795A1 (en) | 2015-06-05 | 2016-06-03 | User terminal, radio base station and radio communication method |
EP16803515.2A EP3307005A4 (en) | 2015-06-05 | 2016-06-03 | User terminal, wireless base station, and wireless communication method |
JP2017522285A JPWO2016195084A1 (ja) | 2015-06-05 | 2016-06-03 | ユーザ端末、無線基地局及び無線通信方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015114900 | 2015-06-05 | ||
JP2015-114900 | 2015-06-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2016195084A1 true WO2016195084A1 (ja) | 2016-12-08 |
Family
ID=57441305
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/066623 WO2016195084A1 (ja) | 2015-06-05 | 2016-06-03 | ユーザ端末、無線基地局及び無線通信方法 |
Country Status (4)
Country | Link |
---|---|
US (1) | US20180302795A1 (ja) |
EP (1) | EP3307005A4 (ja) |
JP (1) | JPWO2016195084A1 (ja) |
WO (1) | WO2016195084A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11985711B2 (en) | 2019-10-17 | 2024-05-14 | Guangdong Oppo Mobile Telecommunications Corp., Ltd. | Devices for indicating channel access parameters |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112312404B (zh) * | 2015-04-08 | 2023-10-24 | 富士通株式会社 | 基站、终端、无线通信系统 |
US20180132260A1 (en) * | 2015-08-13 | 2018-05-10 | Ntt Docomo, Inc. | User terminal, radio base station and radio communication method |
WO2017070055A1 (en) * | 2015-10-19 | 2017-04-27 | Intel IP Corporation | Scheduling uplink transmissions for a user equipment (ue) |
US10721762B2 (en) * | 2016-03-31 | 2020-07-21 | Samsung Electronics Co., Ltd. | Methods for performing multi-subframe scheduling in enhanced LAA |
US10321505B2 (en) | 2016-12-23 | 2019-06-11 | Ofinno, Llc | Dual connectivity based on listen before talk information |
KR20200127393A (ko) | 2019-05-02 | 2020-11-11 | 삼성전자주식회사 | 무선 통신 시스템에서 채널 접속 절차 판단 방법 및 장치 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140301351A1 (en) * | 2011-12-15 | 2014-10-09 | Broadcom Corporation | Centralized Control Sharing of Spectrum for Coexistence of Wireless Communication Systems in Unlicensed Bands |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013112983A2 (en) * | 2012-01-26 | 2013-08-01 | Interdigital Patent Holdings, Inc. | Dynamic parameter adjustment for lte coexistence |
-
2016
- 2016-06-03 US US15/578,788 patent/US20180302795A1/en not_active Abandoned
- 2016-06-03 JP JP2017522285A patent/JPWO2016195084A1/ja active Pending
- 2016-06-03 EP EP16803515.2A patent/EP3307005A4/en not_active Withdrawn
- 2016-06-03 WO PCT/JP2016/066623 patent/WO2016195084A1/ja active Application Filing
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140301351A1 (en) * | 2011-12-15 | 2014-10-09 | Broadcom Corporation | Centralized Control Sharing of Spectrum for Coexistence of Wireless Communication Systems in Unlicensed Bands |
Non-Patent Citations (4)
Title |
---|
INTEL CORPORATION: "Comparison of evaluation results for various UL LBT options", 3GPP TSG-RAN WG1#81 R1-153439, 1 June 2015 (2015-06-01), XP050977905, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_81/Docs/Rl-153439.zip> * |
INTEL ET AL.: "WF on LAA UL LBT", 3GPP TSG-RAN WG1#81 R1-153565, 1 June 2015 (2015-06-01), XP050978861, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_81/Docs/Rl-153565.zip> * |
NTT DOCOMO, INC.: "Discussion on issues related to UL transmission in LAA", 3GPP TSG-RAN WG1#80B R1-151958, 11 April 2015 (2015-04-11), XP050934811, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_80b/Docs/R1-151958.zip> * |
See also references of EP3307005A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11985711B2 (en) | 2019-10-17 | 2024-05-14 | Guangdong Oppo Mobile Telecommunications Corp., Ltd. | Devices for indicating channel access parameters |
Also Published As
Publication number | Publication date |
---|---|
JPWO2016195084A1 (ja) | 2018-04-12 |
US20180302795A1 (en) | 2018-10-18 |
EP3307005A4 (en) | 2018-12-05 |
EP3307005A1 (en) | 2018-04-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2017030053A1 (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
WO2017078034A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
JP6457102B2 (ja) | ユーザ端末及び無線通信方法 | |
WO2016006449A1 (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
WO2016121917A1 (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
WO2017078035A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017022820A1 (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
WO2017026434A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2016195084A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017135346A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017051902A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017026400A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
US11184123B2 (en) | Terminal and radio communication method | |
WO2017051726A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017026488A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017126658A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017051837A1 (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
WO2017026399A1 (ja) | ユーザ端末、無線基地局及び無線通信方法 | |
WO2017026489A1 (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
JP2017175674A (ja) | 無線基地局、ユーザ端末及び無線通信方法 | |
JP6204954B2 (ja) | 無線基地局、ユーザ端末及び無線通信方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 16803515 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15578788 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 2017522285 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2016803515 Country of ref document: EP |