WO2016122249A2 - Procédé d'exécution de lbt dans un système d'accès sans fil prenant en charge une bande sans licence, et appareil prenant en charge le procédé - Google Patents

Procédé d'exécution de lbt dans un système d'accès sans fil prenant en charge une bande sans licence, et appareil prenant en charge le procédé Download PDF

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Publication number
WO2016122249A2
WO2016122249A2 PCT/KR2016/001003 KR2016001003W WO2016122249A2 WO 2016122249 A2 WO2016122249 A2 WO 2016122249A2 KR 2016001003 W KR2016001003 W KR 2016001003W WO 2016122249 A2 WO2016122249 A2 WO 2016122249A2
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Prior art keywords
lbt
cell
cca
terminal
signal
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Korean (ko)
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WO2016122249A3 (fr
Inventor
김선욱
안준기
김병훈
이승민
박한준
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LG Electronics Inc
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LG Electronics Inc
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    • 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
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA

Definitions

  • the present invention relates to a wireless access system supporting an unlicensed band, and more particularly, to methods for efficiently performing List Before Talk (LBT) operation for carrier sensing, and apparatuses for supporting the same.
  • LBT List Before Talk
  • Wireless access systems are widely deployed to provide various kinds of communication services such as voice and data.
  • a wireless access system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.).
  • multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency (SC-FDMA). division multiple access) system.
  • CDMA code division multiple access
  • FDMA frequency division multiple access
  • TDMA time division multiple access
  • OFDMA orthogonal frequency division multiple access
  • SC-FDMA single carrier frequency division multiple access
  • An object of the present invention is to provide methods for performing List Before Talk (LBT) operation to efficiently perform carrier sensing.
  • LBT List Before Talk
  • Another object of the present invention is to provide LBE based LBT methods similar to FBE.
  • Another object of the present invention is to provide an initial LBT and an extended LBT scheme for efficient LBT performance.
  • Another object of the present invention is to provide a method for commonly setting parameters required for performing LBT when transmitting different types of transmission signals.
  • the present invention relates to a wireless access system that supports an unlicensed band, and provides methods for performing an LBT operation for efficiently performing carrier sensing and apparatuses for supporting the same.
  • a method for a terminal to perform an LBT for transmitting an uplink signal in a wireless access system supporting an unlicensed band
  • the terminal performs initial LBT in an unlicensed band cell (U cell)
  • the terminal includes performing an extended LBT and transmitting an uplink signal if the U-cell is idle as a result of performing the initial LBT. If the U-cell is idle as a result of performing the extended LBT, the method may further include transmitting an uplink signal.
  • a terminal for performing List Before Talk (LBT) to transmit an uplink signal in a wireless access system supporting an unlicensed band may include a transmitter, a receiver, and a processor configured to support LBT performance.
  • LBT List Before Talk
  • the processor controls the transmitter and the receiver to perform an initial LBT in an unlicensed band cell (U cell);
  • U cell unlicensed band cell
  • the processor controls the transmitter and the receiver to perform an initial LBT in an unlicensed band cell (U cell);
  • the initial LBT if the U-cell is busy, controlling the transmitter and the receiver to perform extended LBT;
  • the transmitter may be configured to control the transmitter to transmit an uplink signal. If the U-cell is idle as a result of performing extended LBT, the U-cell may be further configured to transmit the uplink signal.
  • the initial LBT is performed to determine whether the U cell is idle or busy without a random backoff
  • the extended LBT performs random backoff by a predetermined number of counters to determine whether the U cell is idle or busy. May be performed to
  • the initial LBT may be performed immediately before the subframe scheduled in the U cell.
  • the UE may drop uplink transmission in the subframe at the time when the LBT is completed or the next sub You can put off frames.
  • the UE may transmit a reservation signal from the time when the extended LBT is completed to just before the next subframe boundary.
  • the initial LBT may be performed before a predetermined time in a subframe scheduled in the U cell. At this time, if the U-cell is idle as a result of performing the initial LBT, the UE may transmit a reservation signal to the next subframe boundary.
  • the terminal since the terminal performs the LBT operation efficiently, the throughput of the UL signal to be transmitted by the terminal can be increased.
  • the UE can flexibly perform LBT operation.
  • the UE can prevent the carrier sanding process from being delayed due to the random backoff.
  • 1 is a diagram illustrating a physical channel and a signal transmission method using the same.
  • FIG. 2 is a diagram illustrating an example of a structure of a radio frame.
  • 3 is a diagram illustrating a resource grid for a downlink slot.
  • FIG. 4 is a diagram illustrating an example of a structure of an uplink subframe.
  • 5 is a diagram illustrating an example of a structure of a downlink subframe.
  • FIG. 6 is a diagram illustrating an example of carrier aggregation used in a component carrier (CC) and LTE_A system.
  • FIG. 7 shows a subframe structure of an LTE-A system according to cross carrier scheduling.
  • FIG. 8 is a diagram illustrating an example of a configuration of a serving cell according to cross carrier scheduling.
  • FIG. 9 is a diagram illustrating one of the SRS transmission methods used in embodiments of the present invention.
  • FIG. 10 is a diagram illustrating an example of a subframe to which a cell specific reference signal (CRS) is allocated, which can be used in embodiments of the present invention.
  • CRS cell specific reference signal
  • FIG. 11 is a diagram illustrating an example of subframes in which CSI-RSs that can be used in embodiments of the present invention are allocated according to the number of antenna ports.
  • FIG. 12 is a diagram illustrating an example in which legacy PDCCH, PDSCH, and E-PDCCH used in an LTE / LTE-A system are multiplexed.
  • FIG. 13 is a diagram illustrating an example of a CA environment supported by an LTE-U system.
  • FIG. 14 is a diagram for describing a case in which cell coverage according to transmission power is set.
  • 15 is a diagram for describing a method of performing power control in an LAA system.
  • FIG. 16 is a diagram to describe a method for transmitting uplink signals based on FBE.
  • FIG. 17 is a diagram for explaining one of FBE-like LBE based LBT performing methods.
  • 18 is a diagram for describing a method of performing extended CCA.
  • 19 is another diagram for describing a method of performing extended CCA.
  • 20 is a view for explaining a modification of the extended CCA execution method.
  • 21 is a diagram for describing methods of performing LBT that does not perform random backoff.
  • FIG. 22 is a diagram for describing FBE-based LBT performing methods without random backoff.
  • FIG. 23 is a diagram for describing a method of setting common parameters for LBT.
  • FIG. 24 is a diagram for describing a method of performing LBT based on FBE-like LBE from a UE perspective.
  • FIG. 25 is a means by which the methods described with reference to FIGS. 1 to 24 may be implemented.
  • the present invention relates to a wireless access system supporting an unlicensed band, and proposes methods for controlling uplink power and apparatuses for supporting the same.
  • each component or feature may be considered to be optional unless otherwise stated.
  • Each component or feature may be embodied in a form that is not combined with other components or features.
  • some components and / or features may be combined to form an embodiment of the present invention.
  • the order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment.
  • the base station is meant as a terminal node of a network that directly communicates with a mobile station.
  • the specific operation described as performed by the base station in this document may be performed by an upper node of the base station in some cases.
  • various operations performed for communication with a mobile station in a network consisting of a plurality of network nodes including a base station may be performed by the base station or network nodes other than the base station.
  • the 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an advanced base station (ABS), or an access point.
  • a terminal may be a user equipment (UE), a mobile station (MS), a subscriber station (SS), or a mobile subscriber station (MSS). It may be replaced with terms such as a mobile terminal or an advanced mobile station (AMS).
  • UE user equipment
  • MS mobile station
  • SS subscriber station
  • MSS mobile subscriber station
  • AMS advanced mobile station
  • the transmitting end refers to a fixed and / or mobile node that provides a data service or a voice service
  • the receiving end refers to a fixed and / or mobile node that receives a data service or a voice service. Therefore, in uplink, a mobile station may be a transmitting end and a base station may be a receiving end. Similarly, in downlink, a mobile station may be a receiving end and a base station may be a transmitting end.
  • Embodiments of the present invention may be supported by standard documents disclosed in at least one of the IEEE 802.xx system, the 3rd Generation Partnership Project (3GPP) system, the 3GPP LTE system, and the 3GPP2 system, which are wireless access systems, and in particular, the present invention.
  • Embodiments of the may be supported by 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321 and 3GPP TS 36.331 documents. That is, obvious steps or portions not described among the embodiments of the present invention may be described with reference to the above documents.
  • all terms disclosed in the present document can be described by the above standard document.
  • Transmission Opportunity Period may be used in the same meaning as the term transmission period or RRP (Reserved Resource Period).
  • RRP Reserved Resource Period
  • the LBT process may be performed for the same purpose as a carrier sensing (CS) process for determining whether a channel state is idle.
  • CS carrier sensing
  • 3GPP LTE / LTE-A system will be described as an example of a wireless access system in which embodiments of the present invention can be used.
  • CDMA code division multiple access
  • FDMA frequency division multiple access
  • TDMA time division multiple access
  • OFDMA orthogonal frequency division multiple access
  • SC-FDMA single carrier frequency division multiple access
  • CDMA may be implemented with a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000.
  • TDMA may be implemented with wireless technologies such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE).
  • GSM Global System for Mobile communications
  • GPRS General Packet Radio Service
  • EDGE Enhanced Data Rates for GSM Evolution
  • OFDMA may be implemented in a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA).
  • UTRA is part of the Universal Mobile Telecommunications System (UMTS).
  • 3GPP Long Term Evolution (LTE) is part of an Evolved UMTS (E-UMTS) using E-UTRA, and employs OFDMA in downlink and SC-FDMA in uplink.
  • LTE-A (Advanced) system is an improved system of the 3GPP LTE system.
  • embodiments of the present invention will be described based on the 3GPP LTE / LTE-A system, but can also be applied to IEEE 802.16e / m system and the like.
  • a terminal receives information from a base station through downlink (DL) and transmits information to the base station through uplink (UL).
  • the information transmitted and received by the base station and the terminal includes general data information and various control information, and various physical channels exist according to the type / use of the information they transmit and receive.
  • FIG. 1 is a diagram for explaining physical channels that can be used in embodiments of the present invention and a signal transmission method using the same.
  • the initial cell search operation such as synchronizing with the base station is performed in step S11.
  • the UE receives a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the base station, synchronizes with the base station, and obtains information such as a cell ID.
  • P-SCH Primary Synchronization Channel
  • S-SCH Secondary Synchronization Channel
  • the terminal may receive a physical broadcast channel (PBCH) signal from the base station to obtain broadcast information in a cell.
  • PBCH physical broadcast channel
  • the terminal may receive a downlink reference signal (DL RS) in the initial cell search step to confirm the downlink channel state.
  • DL RS downlink reference signal
  • the UE After completing the initial cell search, the UE receives a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to the physical downlink control channel information in step S12. Specific system information can be obtained.
  • PDCCH physical downlink control channel
  • PDSCH physical downlink control channel
  • the terminal may perform a random access procedure as in steps S13 to S16 to complete the access to the base station.
  • the UE transmits a preamble through a physical random access channel (PRACH) (S13), a response message to the preamble through a physical downlink control channel and a corresponding physical downlink shared channel. Can be received (S14).
  • PRACH physical random access channel
  • the UE may perform contention resolution such as transmitting an additional physical random access channel signal (S15) and receiving a physical downlink control channel signal and a corresponding physical downlink shared channel signal (S16). Procedure).
  • the UE After performing the above-described procedure, the UE subsequently receives a physical downlink control channel signal and / or a physical downlink shared channel signal (S17) and a physical uplink shared channel (PUSCH) as a general uplink / downlink signal transmission procedure.
  • a transmission (Uplink Shared Channel) signal and / or a Physical Uplink Control Channel (PUCCH) signal may be transmitted (S18).
  • UCI uplink control information
  • HARQ-ACK / NACK Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK
  • SR Scheduling Request
  • CQI Channel Quality Indication
  • PMI Precoding Matrix Indication
  • RI Rank Indication
  • UCI is generally transmitted periodically through the PUCCH, but may be transmitted through the PUSCH when control information and traffic data should be transmitted at the same time.
  • the UCI may be aperiodically transmitted through the PUSCH by the request / instruction of the network.
  • FIG. 2 shows a structure of a radio frame used in embodiments of the present invention.
  • the type 1 frame structure can be applied to both full duplex Frequency Division Duplex (FDD) systems and half duplex FDD systems.
  • FDD Frequency Division Duplex
  • One subframe is defined as two consecutive slots, and the i-th subframe includes slots corresponding to 2i and 2i + 1. That is, a radio frame consists of 10 subframes.
  • the time taken to transmit one subframe is called a transmission time interval (TTI).
  • the slot includes a plurality of OFDM symbols or SC-FDMA symbols in the time domain and a plurality of resource blocks in the frequency domain.
  • One slot includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols in the time domain. Since 3GPP LTE uses OFDMA in downlink, the OFDM symbol is for representing one symbol period. The OFDM symbol may be referred to as one SC-FDMA symbol or symbol period.
  • a resource block is a resource allocation unit and includes a plurality of consecutive subcarriers in one slot.
  • 10 subframes may be used simultaneously for downlink transmission and uplink transmission during each 10ms period. At this time, uplink and downlink transmission are separated in the frequency domain.
  • the terminal cannot transmit and receive at the same time.
  • the structure of the radio frame described above is just one example, and the number of subframes included in the radio frame, the number of slots included in the subframe, and the number of OFDM symbols included in the slot may be variously changed.
  • Type 2 frame structure is applied to the TDD system.
  • the type 2 frame includes a special subframe consisting of three fields: a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS).
  • DwPTS downlink pilot time slot
  • GP guard period
  • UpPTS uplink pilot time slot
  • the DwPTS is used for initial cell search, synchronization or channel estimation in the terminal.
  • UpPTS is used for channel estimation at the base station and synchronization of uplink transmission of the terminal.
  • the guard period is a period for removing interference generated in the uplink due to the multipath delay of the downlink signal between the uplink and the downlink.
  • Table 1 below shows the structure of the special frame (length of DwPTS / GP / UpPTS).
  • FIG. 3 is a diagram illustrating a resource grid for a downlink slot that can be used in embodiments of the present invention.
  • one downlink slot includes a plurality of OFDM symbols in the time domain.
  • one downlink slot includes seven OFDM symbols, and one resource block includes 12 subcarriers in a frequency domain, but is not limited thereto.
  • Each element on the resource grid is a resource element, and one resource block includes 12 ⁇ 7 resource elements.
  • the number NDL of resource blocks included in the downlink slot depends on the downlink transmission bandwidth.
  • the structure of the uplink slot may be the same as the structure of the downlink slot.
  • FIG. 4 shows a structure of an uplink subframe that can be used in embodiments of the present invention.
  • an uplink subframe may be divided into a control region and a data region in the frequency domain.
  • the control region is allocated a PUCCH carrying uplink control information.
  • a PUSCH carrying user data is allocated.
  • one UE does not simultaneously transmit a PUCCH and a PUSCH.
  • the PUCCH for one UE is allocated an RB pair in a subframe. RBs belonging to the RB pair occupy different subcarriers in each of the two slots.
  • the RB pair assigned to this PUCCH is said to be frequency hopping at the slot boundary.
  • FIG. 5 shows a structure of a downlink subframe that can be used in embodiments of the present invention.
  • up to three OFDM symbols from the OFDM symbol index 0 in the first slot in the subframe are control regions to which control channels are allocated, and the remaining OFDM symbols are data regions to which the PDSCH is allocated. to be.
  • a downlink control channel used in 3GPP LTE includes a Physical Control Format Indicator Channel (PCFICH), a PDCCH, and a Physical Hybrid-ARQ Indicator Channel (PHICH).
  • PCFICH Physical Control Format Indicator Channel
  • PDCCH Physical Hybrid-ARQ Indicator Channel
  • PHICH Physical Hybrid-ARQ Indicator Channel
  • the PCFICH is transmitted in the first OFDM symbol of a subframe and carries information about the number of OFDM symbols (ie, the size of the control region) used for transmission of control channels within the subframe.
  • the PHICH is a response channel for the uplink and carries an ACK (Acknowledgement) / NACK (Negative-Acknowledgement) signal for a hybrid automatic repeat request (HARQ).
  • Control information transmitted through the PDCCH is called downlink control information (DCI).
  • the downlink control information includes uplink resource allocation information, downlink resource allocation information or an uplink transmission (Tx) power control command for a certain terminal group.
  • the PDCCH includes resource allocation and transmission format (ie, DL-Grant) of downlink shared channel (DL-SCH) and resource allocation information (ie, uplink grant (UL-) of uplink shared channel (UL-SCH). Grant)), paging information on a paging channel (PCH), system information on a DL-SCH, and an upper-layer control message such as a random access response transmitted on a PDSCH. It may carry resource allocation, a set of transmission power control commands for individual terminals in a certain terminal group, information on whether Voice over IP (VoIP) is activated or the like.
  • VoIP Voice over IP
  • a plurality of PDCCHs may be transmitted in the control region, and the terminal may monitor the plurality of PDCCHs.
  • the PDCCH consists of an aggregation of one or several consecutive control channel elements (CCEs).
  • CCE is a logical allocation unit used to provide a PDCCH with a coding rate according to a state of a radio channel.
  • the CCE corresponds to a plurality of resource element groups (REGs).
  • the format of the PDCCH and the number of bits of the PDCCH are determined according to the correlation between the number of CCEs and the coding rate provided by the CCEs.
  • a plurality of multiplexed PDCCHs for a plurality of terminals may be transmitted in a control region.
  • the PDCCH is composed of one or more consecutive CCE aggregations (CCE aggregation).
  • CCE refers to a unit corresponding to nine sets of REGs consisting of four resource elements.
  • QPSK Quadrature Phase Shift Keying
  • RS reference signal
  • the base station may use ⁇ 1, 2, 4, 8 ⁇ CCEs to configure one PDCCH signal, wherein ⁇ 1, 2, 4, 8 ⁇ is called a CCE aggregation level.
  • the number of CCEs used for transmission of a specific PDCCH is determined by the base station according to the channel state. For example, one CCE may be sufficient for a PDCCH for a terminal having a good downlink channel state (close to the base station). On the other hand, in case of a UE having a bad channel state (when it is at a cell boundary), eight CCEs may be required for sufficient robustness.
  • the power level of the PDCCH may also be adjusted to match the channel state.
  • Table 2 below shows a PDCCH format, and four PDCCH formats are supported as shown in Table 2 according to the CCE aggregation level.
  • the reason why the CCE aggregation level is different for each UE is because a format or a modulation and coding scheme (MCS) level of control information carried on the PDCCH is different.
  • MCS level refers to a code rate and a modulation order used for data coding.
  • Adaptive MCS levels are used for link adaptation. In general, three to four MCS levels may be considered in a control channel for transmitting control information.
  • control information transmitted through the PDCCH is referred to as downlink control information (DCI).
  • DCI downlink control information
  • the configuration of information carried in the PDCCH payload may vary.
  • the PDCCH payload means an information bit. Table 3 below shows DCI according to DCI format.
  • a DCI format includes a format 0 for PUSCH scheduling, a format 1 for scheduling one PDSCH codeword, a format 1A for compact scheduling of one PDSCH codeword, and a very much DL-SCH.
  • Format 1C for simple scheduling, format 2 for PDSCH scheduling in closed-loop spatial multiplexing mode, format 2A for PDSCH scheduling in open-loop spatial multiplexing mode, for uplink channel
  • Format 3 and 3A for the transmission of Transmission Power Control (TPC) commands.
  • DCI format 1A may be used for PDSCH scheduling, regardless of which transmission mode is configured for the UE.
  • the PDCCH payload length may vary depending on the DCI format.
  • the type and length thereof of the PDCCH payload may vary depending on whether it is a simple scheduling or a transmission mode set in the terminal.
  • the transmission mode may be configured for the UE to receive downlink data through the PDSCH.
  • the downlink data through the PDSCH may include scheduled data, paging, random access response, or broadcast information through BCCH.
  • Downlink data through the PDSCH is related to the DCI format signaled through the PDCCH.
  • the transmission mode may be set semi-statically to the terminal through higher layer signaling (eg, RRC (Radio Resource Control) signaling).
  • the transmission mode may be classified into single antenna transmission or multi-antenna transmission.
  • the terminal is set to a semi-static transmission mode through higher layer signaling.
  • multi-antenna transmission includes transmit diversity, open-loop or closed-loop spatial multiplexing, and multi-user-multiple input multiple outputs.
  • beamforming Transmit diversity is a technique of increasing transmission reliability by transmitting the same data in multiple transmit antennas.
  • Spatial multiplexing is a technology that allows high-speed data transmission without increasing the bandwidth of the system by simultaneously transmitting different data from multiple transmit antennas.
  • Beamforming is a technique of increasing the signal to interference plus noise ratio (SINR) of a signal by applying weights according to channel conditions in multiple antennas.
  • SINR signal to interference plus noise ratio
  • the DCI format is dependent on a transmission mode configured in the terminal (depend on).
  • the UE has a reference DCI format that monitors according to a transmission mode configured for the UE.
  • the transmission mode set in the terminal may have ten transmission modes as follows.
  • transmission mode 1 single antenna port; Port 0
  • Transmission mode 7 Precoding supporting single layer transmission not based on codebook
  • Transmission mode 8 Precoding supporting up to two layers not based on codebook
  • Transmission mode 9 Precoding supporting up to eight layers not based on codebook
  • Transmission mode 10 precoding supporting up to eight layers, used for CoMP, not based on codebook
  • the base station determines the PDCCH format according to the DCI to be transmitted to the terminal, and attaches a CRC (Cyclic Redundancy Check) to the control information.
  • a unique identifier for example, a Radio Network Temporary Identifier (RNTI)
  • RNTI Radio Network Temporary Identifier
  • a paging indication identifier (eg, P-RNTI (P-RNTI)) may be masked to the CRC.
  • P-RNTI P-RNTI
  • SI-RNTI System Information RNTI
  • RA-RNTI random access-RNTI
  • the base station performs channel coding on the control information added with the CRC to generate coded data.
  • channel coding may be performed at a code rate according to the MCS level.
  • the base station performs rate matching according to the CCE aggregation level allocated to the PDCCH format, modulates the coded data, and generates modulation symbols.
  • a modulation sequence according to the MCS level can be used.
  • the modulation symbols constituting one PDCCH may have one of 1, 2, 4, and 8 CCE aggregation levels.
  • the base station maps modulation symbols to physical resource elements (CCE to RE mapping).
  • a plurality of PDCCHs may be transmitted in one subframe. That is, the control region of one subframe includes a plurality of CCEs having indices 0 to N CCE, k ⁇ 1.
  • N CCE, k means the total number of CCEs in the control region of the kth subframe.
  • the UE monitors the plurality of PDCCHs in every subframe. Here, monitoring means that the UE attempts to decode each of the PDCCHs according to the monitored PDCCH format.
  • blind decoding refers to a method in which a UE de-masks its UE ID in a CRC portion and then checks the CRC error to determine whether the corresponding PDCCH is its control channel.
  • the UE monitors the PDCCH of every subframe in order to receive data transmitted to the UE.
  • the UE wakes up in the monitoring interval of every DRX cycle and monitors the PDCCH in a subframe corresponding to the monitoring interval.
  • a subframe in which PDCCH monitoring is performed is called a non-DRX subframe.
  • the UE In order to receive the PDCCH transmitted to the UE, the UE must perform blind decoding on all CCEs present in the control region of the non-DRX subframe. Since the UE does not know which PDCCH format is transmitted, it is necessary to decode all PDCCHs at the CCE aggregation level possible until blind decoding of the PDCCH is successful in every non-DRX subframe. Since the UE does not know how many CCEs the PDCCH uses for itself, the UE should attempt detection at all possible CCE aggregation levels until the blind decoding of the PDCCH succeeds.
  • a search space (SS) concept is defined for blind decoding of a terminal.
  • the search space means a PDCCH candidate set for the UE to monitor and may have a different size according to each PDCCH format.
  • the search space may include a common search space (CSS) and a UE-specific / dedicated search space (USS).
  • the UE In the case of the common search space, all terminals can know the size of the common search space, but the terminal specific search space can be set individually for each terminal. Accordingly, the UE must monitor both the UE-specific search space and the common search space in order to decode the PDCCH, thus performing a maximum of 44 blind decoding (BDs) in one subframe. This does not include blind decoding performed according to different CRC values (eg, C-RNTI, P-RNTI, SI-RNTI, RA-RNTI).
  • CRC values eg, C-RNTI, P-RNTI, SI-RNTI, RA-RNTI
  • the base station may not be able to secure the CCE resources for transmitting the PDCCH to all the terminals to transmit the PDCCH in a given subframe. This is because resources remaining after the CCE location is allocated may not be included in the search space of a specific UE.
  • a terminal specific hopping sequence may be applied to the starting point of the terminal specific search space to minimize this barrier that may continue to the next subframe.
  • Table 4 shows the sizes of the common search space and the terminal specific search space.
  • the UE does not simultaneously perform searches according to all defined DCI formats. Specifically, the terminal always performs a search for DCI formats 0 and 1A in the terminal specific search space (USS). In this case, the DCI formats 0 and 1A have the same size, but the UE may distinguish the DCI formats by using a flag used for distinguishing the DCI formats 0 and 1A included in the PDCCH. In addition, a DCI format other than DCI format 0 and DCI format 1A may be required for the UE. Examples of the DCI formats include 1, 1B, and 2.
  • the UE may search for DCI formats 1A and 1C.
  • the UE may be configured to search for DCI format 3 or 3A, and DCI formats 3 and 3A have the same size as DCI formats 0 and 1A, but the UE uses a CRC scrambled by an identifier other than the UE specific identifier.
  • the DCI format can be distinguished.
  • the CCE according to the PDCCH candidate set m of the search space may be determined by Equation 1 below.
  • M (L) represents the number of PDCCH candidates according to CCE aggregation level L for monitoring in search space, to be.
  • N s represents a slot index in a radio frame.
  • the UE monitors both the UE-specific search space and the common search space to decode the PDCCH.
  • the common search space (CSS) supports PDCCHs having an aggregation level of ⁇ 4, 8 ⁇
  • the UE specific search space supports PDCCHs having an aggregation level of ⁇ 1, 2, 4, 8 ⁇ .
  • Table 5 shows PDCCH candidates monitored by the UE.
  • Y k is defined as in Equation 2.
  • CA Carrier Aggregation
  • LTE system 3rd Generation Partnership Project Long Term Evolution (Rel-8 or Rel-9) system
  • MCM multi-carrier modulation
  • CC component carrier
  • Multi-Carrier Modulation is used.
  • LTE-A system a method such as Carrier Aggregation (CA) may be used in which one or more component carriers are combined to support a wider system bandwidth than the LTE system.
  • CA Carrier Aggregation
  • Carrier aggregation may be replaced with the words carrier aggregation, carrier matching, multi-component carrier environment (Multi-CC) or multicarrier environment.
  • the multi-carrier means the aggregation of carriers (or carrier aggregation), wherein the aggregation of carriers means not only merging between contiguous carriers but also merging between non-contiguous carriers.
  • the number of component carriers aggregated between downlink and uplink may be set differently.
  • the case where the number of downlink component carriers (hereinafter referred to as 'DL CC') and the number of uplink component carriers (hereinafter referred to as 'UL CC') is the same is called symmetric merging. This is called asymmetric merging.
  • Such carrier aggregation may be used interchangeably with terms such as carrier aggregation, bandwidth aggregation, spectrum aggregation, and the like.
  • Carrier aggregation in which two or more component carriers are combined, aims to support up to 100 MHz bandwidth in an LTE-A system.
  • the bandwidth of the combining carrier may be limited to the bandwidth used by the existing system to maintain backward compatibility with the existing IMT system.
  • the existing 3GPP LTE system supports ⁇ 1.4, 3, 5, 10, 15, 20 ⁇ MHz bandwidth
  • the 3GPP LTE-advanced system i.e., LTE-A
  • LTE-A 3GPP LTE-advanced system
  • the carrier aggregation system used in the present invention may support carrier aggregation by defining a new bandwidth regardless of the bandwidth used in the existing system.
  • the carrier aggregation may be divided into an intra-band CA and an inter-band CA.
  • Intra-band carrier merging means that a plurality of DL CCs and / or UL CCs are located adjacent to or in proximity to frequency. In other words, it may mean that the carrier frequencies of the DL CCs and / or UL CCs are located in the same band.
  • an environment far from the frequency domain may be referred to as an inter-band CA.
  • the terminal may use a plurality of radio frequency (RF) terminals to perform communication in a carrier aggregation environment.
  • RF radio frequency
  • the LTE-A system uses the concept of a cell to manage radio resources.
  • the carrier aggregation environment described above may be referred to as a multiple cell environment.
  • a cell is defined as a combination of a downlink resource (DL CC) and an uplink resource (UL CC), but the uplink resource is not an essential element. Accordingly, the cell may be configured with only downlink resources or with downlink resources and uplink resources.
  • a specific UE when a specific UE has only one configured serving cell, it may have one DL CC and one UL CC. However, when a specific terminal has two or more configured serving cells, it may have as many DL CCs as the number of cells and the number of UL CCs may be the same or smaller than that. Alternatively, the DL CC and the UL CC may be configured on the contrary. That is, when a specific UE has a plurality of configured serving cells, a carrier aggregation environment in which a UL CC has more than the number of DL CCs may be supported.
  • Carrier coupling may also be understood as the merging of two or more cells, each having a different carrier frequency (center frequency of the cell).
  • the term 'cell' in terms of carrier combining is described in terms of frequency, and should be distinguished from 'cell' as a geographical area covered by a commonly used base station.
  • intra-band carrier merging is referred to as an intra-band multi-cell
  • inter-band carrier merging is referred to as an inter-band multi-cell.
  • the cell used in the LTE-A system includes a primary cell (P cell) and a secondary cell (S cell).
  • the PCell and the SCell may be used as serving cells.
  • the UE that is in the RRC_CONNECTED state but the carrier aggregation is not configured or does not support the carrier aggregation, there is only one serving cell composed of the PCell.
  • one or more serving cells may exist, and the entire serving cell includes a PCell and one or more SCells.
  • Serving cells may be configured through an RRC parameter.
  • PhyS cell Id is a cell's physical layer identifier and has an integer value from 0 to 503.
  • SCell Index is a short identifier used to identify SCell and has an integer value from 1 to 7.
  • ServCellIndex is a short identifier used to identify a serving cell (P cell or S cell) and has an integer value from 0 to 7. A value of 0 is applied to the P cell, and the S cell Index is given in advance to apply to the S cell. That is, a cell having the smallest cell ID (or cell index) in ServCellIndex becomes a P cell.
  • P cell refers to a cell operating on a primary frequency (or primary CC).
  • the UE may be used to perform an initial connection establishment process or to perform a connection re-establishment process, and may also refer to a cell indicated in a handover process.
  • the P cell refers to a cell serving as a center of control-related communication among serving cells configured in a carrier aggregation environment. That is, the terminal may receive and transmit a PUCCH only in its own Pcell, and may use only the Pcell to acquire system information or change a monitoring procedure.
  • E-UTRAN Evolved Universal Terrestrial Radio Access
  • RRC ConnectionReconfigutaion message of a higher layer including mobility control information to a UE supporting a carrier aggregation environment. It may be.
  • the S cell may refer to a cell operating on a secondary frequency (or, secondary CC). Only one PCell may be allocated to a specific UE, and one or more SCells may be allocated.
  • the SCell is configurable after the RRC connection is established and may be used to provide additional radio resources.
  • PUCCH does not exist in the remaining cells excluding the P cell, that is, the S cell, among the serving cells configured in the carrier aggregation environment.
  • the E-UTRAN may provide all system information related to the operation of the related cell in the RRC_CONNECTED state through a dedicated signal.
  • the change of the system information may be controlled by the release and addition of the related SCell, and at this time, an RRC connection reconfigutaion message of a higher layer may be used.
  • the E-UTRAN may transmit specific signaling having different parameters for each terminal, rather than broadcasting in the related SCell.
  • the E-UTRAN may configure a network including one or more Scells in addition to the Pcells initially configured in the connection establishment process.
  • the Pcell and the SCell may operate as respective component carriers.
  • the primary component carrier (PCC) may be used in the same sense as the PCell
  • the secondary component carrier (SCC) may be used in the same sense as the SCell.
  • FIG. 6 is a diagram illustrating an example of carrier aggregation used in a component carrier (CC) and an LTE_A system used in embodiments of the present invention.
  • Component carriers include a DL CC and an UL CC.
  • One component carrier may have a frequency range of 20 MHz.
  • 6 (b) shows a carrier aggregation structure used in the LTE_A system.
  • 6 (b) shows a case where three component carriers having a frequency size of 20 MHz are combined.
  • the number of DL CCs and UL CCs is not limited.
  • the UE may simultaneously monitor three CCs, receive downlink signals / data, and transmit uplink signals / data.
  • the network may allocate M (M ⁇ N) DL CCs to the UE.
  • the UE may monitor only M limited DL CCs and receive a DL signal.
  • the network may assign L (L ⁇ M ⁇ N) DL CCs to allocate a main DL CC to the UE, in which case the UE must monitor the L DL CCs. This method can be equally applied to uplink transmission.
  • the linkage between the carrier frequency (or DL CC) of the downlink resource and the carrier frequency (or UL CC) of the uplink resource may be indicated by a higher layer message or system information such as an RRC message.
  • a combination of DL resources and UL resources may be configured by a linkage defined by SIB2 (System Information Block Type2).
  • SIB2 System Information Block Type2
  • the linkage may mean a mapping relationship between a DL CC on which a PDCCH carrying a UL grant is transmitted and a UL CC using the UL grant, and a DL CC (or UL CC) and HARQ ACK on which data for HARQ is transmitted. It may mean a mapping relationship between UL CCs (or DL CCs) through which a / NACK signal is transmitted.
  • Cross carrier scheduling may be referred to as Cross Component Carrier Scheduling or Cross Cell Scheduling.
  • Self-scheduling is transmitted through a DL CC in which a PDCCH (DL Grant) and a PDSCH are transmitted in the same DL CC, or a PUSCH transmitted according to a PDCCH (UL Grant) transmitted in a DL CC is linked to a DL CC in which a UL Grant has been received. It means to be.
  • a DL CC in which a PDCCH (DL Grant) and a PDSCH are transmitted to different DL CCs or a UL CC in which a PUSCH transmitted according to a PDCCH (UL Grant) transmitted in a DL CC is linked to a DL CC having received an UL grant This means that it is transmitted through other UL CC.
  • Whether to perform cross-carrier scheduling may be activated or deactivated UE-specifically and may be known for each UE semi-statically through higher layer signaling (eg, RRC signaling).
  • higher layer signaling eg, RRC signaling
  • a carrier indicator field (CIF: Carrier Indicator Field) indicating a PDSCH / PUSCH indicated by the corresponding PDCCH is transmitted to the PDCCH.
  • the PDCCH may allocate PDSCH resource or PUSCH resource to one of a plurality of component carriers using CIF. That is, when the PDCCH on the DL CC allocates PDSCH or PUSCH resources to one of the multi-aggregated DL / UL CC, CIF is set.
  • the DCI format of LTE Release-8 may be extended according to CIF.
  • the set CIF may be fixed as a 3 bit field or the position of the set CIF may be fixed regardless of the DCI format size.
  • the PDCCH structure (same coding and resource mapping based on the same CCE) of LTE Release-8 may be reused.
  • the PDCCH on the DL CC allocates PDSCH resources on the same DL CC or PUSCH resources on a single linked UL CC, CIF is not configured.
  • the same PDCCH structure (same coding and resource mapping based on the same CCE) and DCI format as in LTE Release-8 may be used.
  • the UE When cross carrier scheduling is possible, the UE needs to monitor the PDCCHs for the plurality of DCIs in the control region of the monitoring CC according to the transmission mode and / or bandwidth for each CC. Therefore, it is necessary to configure the search space and PDCCH monitoring that can support this.
  • the terminal DL CC set represents a set of DL CCs scheduled for the terminal to receive a PDSCH
  • the terminal UL CC set represents a set of UL CCs scheduled for the terminal to transmit a PUSCH.
  • the PDCCH monitoring set represents a set of at least one DL CC that performs PDCCH monitoring.
  • the PDCCH monitoring set may be the same as the terminal DL CC set or may be a subset of the terminal DL CC set.
  • the PDCCH monitoring set may include at least one of DL CCs in the terminal DL CC set. Alternatively, the PDCCH monitoring set may be defined separately regardless of the UE DL CC set.
  • the DL CC included in the PDCCH monitoring set may be configured to always enable self-scheduling for the linked UL CC.
  • the UE DL CC set, the UE UL CC set, and the PDCCH monitoring set may be configured UE-specifically, UE group-specifically, or cell-specifically.
  • cross-carrier scheduling When cross-carrier scheduling is deactivated, it means that the PDCCH monitoring set is always the same as the UE DL CC set. In this case, an indication such as separate signaling for the PDCCH monitoring set is not necessary.
  • a PDCCH monitoring set is defined in the terminal DL CC set. That is, in order to schedule PDSCH or PUSCH for the UE, the base station transmits the PDCCH through only the PDCCH monitoring set.
  • FIG. 7 illustrates a subframe structure of an LTE-A system according to cross carrier scheduling used in embodiments of the present invention.
  • DL CC 'A' represents a case in which a PDCCH monitoring DL CC is configured.
  • each DL CC may transmit a PDCCH for scheduling its PDSCH without CIF.
  • the CIF is used through higher layer signaling, only one DL CC 'A' may transmit a PDCCH for scheduling its PDSCH or PDSCH of another CC using the CIF.
  • DL CCs 'B' and 'C' that are not configured as PDCCH monitoring DL CCs do not transmit the PDCCH.
  • FIG. 8 is a diagram illustrating an example of a configuration of a serving cell according to cross carrier scheduling used in embodiments of the present invention.
  • a base station and / or terminals may be composed of one or more serving cells.
  • the base station can support a total of four serving cells, such as A cell, B cell, C cell, and D cell, and terminal A is composed of A cell, B cell, and C cell, and terminal B is B cell, C cell, and the like. It is assumed that the D cell and the terminal C is configured as a B cell. In this case, at least one of the cells configured in each terminal may be configured as a P cell.
  • the PCell is always in an activated state, and the SCell may be activated or deactivated by the base station and / or the terminal.
  • the cell configured in FIG. 8 is a cell capable of adding a cell to a CA based on a measurement report message from a terminal among cells of a base station, and may be configured for each terminal.
  • the configured cell reserves the resources for the ACK / NACK message transmission for the PDSCH signal transmission in advance.
  • An activated cell is a cell configured to transmit a real PDSCH signal and / or a PUSCH signal among configured cells, and performs CSI reporting and SRS (Sounding Reference Signal) transmission.
  • a de-activated cell is a cell configured not to transmit or receive a PDSCH / PUSCH signal by a command or timer operation of a base station, and also stops CSI reporting and SRS transmission.
  • CoMP transmission may be implemented using a carrier aggregation (CA) function in LTE.
  • CA carrier aggregation
  • a carrier operating as a PCell and a carrier operating as an SCell may use the same frequency band as the frequency axis, and are allocated to two geographically separated eNBs.
  • the serving eNB of the UE1 may be allocated to the Pcell, and the neighboring cell which gives a lot of interference may be allocated to the Scell. That is, the base station of the P cell and the base station of the S cell may perform various DL / UL CoMP operations such as joint transmission (JT), CS / CB, and dynamic cell selection with respect to one UE.
  • FIG. 9 shows an example of combining cells managed by two eNBs for one UE (e.g. UE1) as a Pcell and an Scell, respectively.
  • one UE e.g. UE1
  • three or more cells may be combined.
  • some of the three or more cells may be configured to perform a CoMP operation on one terminal in the same frequency band, and other cells to perform a simple CA operation in another frequency band.
  • the Pcell does not necessarily participate in CoMP operation.
  • FIG. 10 is a diagram illustrating an example of a subframe to which a UE-specific reference signal (UE-RS) that can be used in embodiments of the present invention is allocated.
  • UE-RS UE-specific reference signal
  • a corresponding subframe illustrates REs occupied by UE-RS among REs in a resource block pair of a regular downlink subframe having a normal CP.
  • the UE-RS exists when PDSCH transmission is associated with a corresponding antenna port, and is a valid reference signal only for demodulation of the PDSCH signal.
  • the UE-RS is transmitted only on the RBs to which the corresponding PDSCH signal is mapped. That is, the UE-RS is configured to be transmitted only in the RB (s) to which the PDSCH is mapped in the subframe in which the PDSCH is scheduled, unlike the CRS (Cell Specific Reference Signal) configured to be transmitted in every subframe regardless of the presence or absence of the PDSCH. .
  • the CRS Cell Specific Reference Signal
  • the UE-RS is transmitted only through the antenna port (s) respectively corresponding to the layer (s) of the PDSCH. Therefore, using the UE-RS, the overhead of the RS can be reduced compared to the CRS.
  • the CRS and the UE-RS, etc. refer to TS 36.211 and 36.213 standards of the 3GPP LTE-A system.
  • the UE-RS is transmitted through antenna port (s) respectively corresponding to the layer (s) of the PDSCH. That is, it can be seen that the number of UE-RS ports is proportional to the transmission rank of the PDSCH. On the other hand, if the number of layers is 1 or 2, 12 REs are used for UE-RS transmission for each RB pair. If the number of layers is more than 2, 24 REs are used for UE-RS transmission for each RB pair. In addition, the positions of REs (ie, UE-RS REs) occupied by the UE-RS in the RB pair regardless of the UE or the cell are the same for each UE-RS port.
  • the number of DM-RS REs is the same in RBs in which PDSCHs for specific UEs are mapped in specific subframes.
  • the number of DM-RS REs included in corresponding RBs may vary according to the number of layers transmitted.
  • the UE-RS may be used in the same meaning as the DM-RS.
  • a cross carrier scheduling (CCS) operation in a combined situation for a plurality of component carrier (CC) cells
  • CC cross carrier scheduling
  • the scheduled CC may be preset to receive DL / UL scheduling only from another scheduling CC (ie, to receive a DL / UL grant PDCCH for the scheduled CC).
  • the scheduling CC may basically perform DL / UL scheduling on itself.
  • the number of OFDM symbols used for transmission of control channels in each subframe may be delivered to the UE dynamically through a physical channel such as PCFICH or in a semi-static manner through RRC signaling.
  • the PDCCH which is a physical channel for transmitting DL / UL scheduling and various control information, has a limitation such as being transmitted through limited OFDM symbols.
  • the PDCCH is transmitted through an OFDM symbol separate from the PDSCH, such as a PDCCH.
  • An extended PDCCH ie E-PDCCH
  • FIG. 11 is a diagram illustrating an example in which legacy PDCCH, PDSCH, and E-PDCCH used in an LTE / LTE-A system are multiplexed.
  • the LTE-U system refers to an LTE system supporting CA conditions of the licensed band and the unlicensed band.
  • the unlicensed band may be a Wi-Fi band or a Bluetooth (BT) band.
  • FIG. 12 is a diagram illustrating an example of a CA environment supported by an LTE-U system.
  • CCs component carriers
  • a licensed CC (LCC: Licensed CC) is a major carrier (can be referred to as a primary CC (PCC or PCell)), an unlicensed carrier (Unlicensed CC: UCC) is a sub-carrier Assume a case of (Secondary CC: SCC or S cell).
  • LCC Licensed CC
  • UCC unlicensed carrier
  • embodiments of the present invention may be extended to a situation in which a plurality of licensed bands and a plurality of unlicensed bands are used in a carrier combining method.
  • the proposed schemes of the present invention can be extended to not only 3GPP LTE system but also other system.
  • the terminal can transmit and receive control information and data through a PCC, which is a licensed band, and can also transmit and receive control information and data through an SCC, which is an unlicensed band.
  • PCC which is a licensed band
  • SCC which is an unlicensed band
  • the terminal may configure a P-cell and a macro base station (M-eNB: Macro eNB) and a small cell (S-eNB: Small eNB) and an S cell.
  • M-eNB Macro eNB
  • S-eNB Small eNB
  • the macro base station and the small base station may be connected through a backhaul network.
  • the unlicensed band may be operated in a contention based random access scheme.
  • the eNB supporting the unlicensed band may first perform a carrier sensing (CS) process before data transmission and reception.
  • the CS process is a process of determining whether the corresponding band is occupied by another entity.
  • the eNB of the SCell checks whether the current channel is busy or idle. If the corresponding band is determined to be in an idle state, the base station transmits a scheduling grant to the UE through the (E) PDCCH of the Pcell in the case of the cross-carrier scheduling or the PDCCH of the Scell in the case of the self-scheduling scheme. Resource allocation and data transmission and reception.
  • the base station may set a transmission opportunity (TxOP) section consisting of M consecutive subframes.
  • TxOP transmission opportunity
  • the base station may inform the UE of the M value and the use of the M subframes in advance through a higher layer signal, a physical control channel, or a physical data channel through a Pcell.
  • a TxOP period consisting of M subframes may be called a reserved resource period (RRP).
  • the CS process may be referred to as a clear channel assessment (CCA) process, and a channel is busy or idle based on a CCA threshold set through a preset or higher layer signal. It can be determined as. For example, if an energy higher than the CCA threshold is detected in an S cell that is an unlicensed band, it may be determined to be busy or idle. At this time, if the channel state is determined to be idle, the base station may start signal transmission in the SCell. This series of processes may be called List-Before-Talk (LBT).
  • LBT List-Before-Talk
  • FIG. 13 is a diagram illustrating an example of an FBE operation that is one of LBT processes.
  • the European ETSI regulation (EN 301 893 V1.7.1) illustrates two LBT operations, called Frame Based Equipment (FBE) and Load Based Equipment (LBE).
  • FBE is equivalent to Channel Occupancy Time (eg, 1 to 10ms) and at least 5% of the channel occupancy time, which is the length of time that a communication node can continue transmitting when it succeeds in channel access.
  • the idle period (Idle Period) constitutes one fixed frame, and CCA is defined as an operation of observing a channel for a CCA slot (at least 20 ⁇ s) at the end of the idle period.
  • the communication node periodically performs CCA on a fixed frame basis. If the channel is in the Unoccupied state, the communication node transmits data during the channel occupancy time. If the channel is in the occupied state, the communication node suspends transmission and waits until the next cycle of the CCA slot.
  • FIG. 14 is a block diagram illustrating an FBE operation.
  • a communication node ie, a base station managing an SCell performs a CCA process during a CCA slot. If the channel is in the idle state, the communication node performs data transmission (Tx). If the channel is in the busy state, the communication node waits as long as the CCA slot is subtracted from the fixed frame period and then performs the CCA process again.
  • Tx data transmission
  • the communication node performs data transmission during the channel occupancy time, and after the data transmission is completed, waits for the time obtained by subtracting the CCA slot from the idle period and then performs the CCA process again. If the channel is idle or there is no data to be transmitted, the communication node waits for the time subtracting the CCA slot from the fixed frame period and then performs the CCA process again.
  • 15 is a diagram illustrating an example of an LBE operation that is one of LBT processes.
  • the communication node first performs q ⁇ ⁇ 4, 5,... , 32 ⁇ and CCA for one CCA slot.
  • FIG. 15 (b) is a block diagram of the LBE operation. The LBE operation will be described with reference to FIG. 15 (b).
  • the communication node may perform a CCA process in the CCA slot. If the channel is not occupied in the first CCA slot, the communication node may transmit data by securing a maximum (13/32) q ms length of time.
  • the communication node randomly (i.e., randomly) N ⁇ ⁇ 1, 2,... If the channel is not occupied in a specific CCA slot, the counter value is decreased by one. When the counter value reaches zero, the communication node can transmit data with a maximum length of (13/32) q ms.
  • a communication node eg, terminal and / or base station operating in an FBE based LBT scheme.
  • the communication node may be sent every SF (or every 1 ms) even if the communication node wants to transmit or receive data in the unlicensed band for more than 1 ms.
  • a CCA should be performed to determine whether the corresponding radio channel is idle.
  • a timing gap of 50 us for every SF (or every 1 ms) transmission must be configured as an idle period for at least 50 us (5% of 1 ms). gap) exists. Accordingly, a hidden node problem may occur that allows channel access to the LAA system from a Wi-Fi system or another operator that coexists in an unlicensed band during the corresponding idle period. In addition, damage may occur in terms of spectral efficiency because the communication node may not transmit or receive data during the idle period.
  • a communication node eg, a terminal and / or a base station operating in the LBE-based LBT scheme.
  • the CCA may be performed immediately before the start of the fixed frame period, whereas in the case of the LBE, the CCA may be performed at any time without restriction of the CCA timing.
  • the communication node if the channel is idle during the CCA slot, or if the counter value is '0' by performing extended CCA (i.e., below the Maximum Channel Occupancy Time), the communication node will wait for the desired time for channel occupancy. Configure and perform CCA (or Extended CCA).
  • the communication node starts to transmit and receive PDCCH, PDSCH, PUCCH and / or PUSCH only from the SF boundary of the LTE / LTE-A system. Can be. Therefore, a timing gap may exist between the SF boundary and the time when it is determined that transmission can be started in the unlicensed band.
  • transmission of a reservation signal or the like is required, and this reservation signal may not contain actual information, which may cause waste of radio resources. As a result, the reservation signal may cause interference to other communication nodes, which may reduce communication performance.
  • the present invention provides LBT schemes capable of data transmission according to the SF boundary of the LTE / LTE-A system.
  • Embodiments of the present invention describe the uplink signal transmission scheme that the terminal transmits to the base station, but these schemes may be applied to the downlink signal transmission scheme.
  • the uplink signal is used to mean uplink data, uplink control information, and uplink reference signal
  • the downlink signal is used for downlink data, downlink control information, and downlink reference signal. It can be used as a meaning including.
  • FIG. 16 is a diagram to describe a method for transmitting uplink signals based on FBE.
  • an L-cell (L-cell: licensed band cell) refers to a serving cell defined and operated in a licensed band
  • an U-cell U-cell: Unlicensed band cell
  • the L cell performs operations defined in the LTE / LTE-A system and may refer to the contents of Sections 1 to 2.
  • FIG. 16 (a) is a diagram for describing a FBE-based UL transmission method in which a LAA UE configures a fixed frame interval of 1 ms. It may be assumed that the terminal receives scheduling from the base station for 3 consecutive SFs from SF #N. The UE may start the UL signal when the channel is not occupied by performing CCA immediately before SF #N. In consideration of the fixed frame interval of 1ms, the idle interval is preferably set to a time of at least 50us. To this end, the TX burst in FIG. 16 (a) does not include the last OFDM symbol of a particular SF. The last OFDM symbol of SF not included in the TX burst may be defined as a CCA gap.
  • the UE performs an LBT (or carrier sanding) operation during the CCA gap, and may define the UL signal transmitted by the UE during the channel occupancy time after every LBT operation as a TX burst. If the channel is in a non-occupied state by performing CCA on the scheduled SF immediately before the SF boundary, the UE may attempt UL transmission by configuring a TX burst for a time period excluding the CCA gap of the corresponding SF. That is, even if three consecutive SFs are scheduled from SF #N, the UE must perform CCA immediately before each SF.
  • LBT carrier sanding
  • FIG. 16 (b) shows that the UE is scheduled for three SFs, but if the CCA result channel performed immediately before the SF #N boundary is occupied (ie, busy), transmission of the corresponding SF #N is dropped and SF CCA may be performed immediately before the # N + 1 boundary, and if the corresponding channel is not occupied (ie, idle), TX burst transmission may be performed.
  • the LBT operation proposed in the following embodiments operates on an LBE basis as described in FIG. 15, and additionally has the following features.
  • the UE may perform an "Initial CCA" only immediately before every SF boundary.
  • the UE may perform UL signal transmission in the scheduled SF only when the initial CCA result channel is in an unoccupied state.
  • the terminal may perform an "Extended CCA (Extended CCA)".
  • the UE may drop the UL signal transmission for the SF (s) that partially overlap with the interval where the extended CCA is performed or delay the UL signal transmission to the next SF.
  • the initial CCA proposed by the present invention may be performed to determine whether the U-cell is idle or busy without a random backoff.
  • the proposed extended CCA may follow the current EU regulations (e.g., EN 301 893 V1.7.1) as defined by the LBE, but any backoff counter (or interval) value may be drawn to determine the backoff counter value. It may be a concept including various backoff algorithms that perform CCA until it becomes '0' (or during a set interval).
  • CCA is performed in the LBT process, which may be described with reference to FIGS. 13 and 14.
  • CS, CCA and LBT may be used in the same sense.
  • the initial CCA may be used in the same sense as the initial LBT
  • the extended CCA may be used in the same meaning as the extended LBT.
  • FIG. 17 is a diagram for explaining one of FBE-like LBE based LBT performing methods.
  • the LAA terminal is scheduled for three SFs consecutively from SF #N. That is, the LAA terminal may perform an initial CCA immediately before SF #N, and if the channel is in an unoccupied state (that is, in an idle state), the LAA terminal may transmit a UL signal by continuously configuring a TX burst for 3 SFs. In the last SF, SF # N + 2, at least one OFDM symbol may be empty for the CCA gap. In FIG. 17, since the initial CCA resultant channel is idle, the LAA terminal performs Tx burst transmission in SF #N and does not perform extended CCA.
  • 18 is a diagram for describing a method of performing extended CCA.
  • the LAA terminal is scheduled for 3 SFs from SF #N.
  • the LAA terminal may transmit the UL signal through the scheduled SF only when the U cell of the unlicensed band is in an idle state.
  • the terminal performs initial CCA immediately before SF #N, and performs extended CCA when the channel is occupied (ie, busy). If the extended CCA ends before the SF # N + 1 boundary, the UE drops the UL signal transmission scheduled in the SF #N and performs CCA just before the SF # N + 1 boundary.
  • the UE may configure and transmit a TX burst for two consecutive SFs, and in SF # N + 2, at least one OFDM symbol may be left blank for the CCA gap. That is, although the UE has been continuously allocated three SFs, the TX burst configured at SF # N + 1 is composed of 2 SFs instead of 3 SFs, and is characterized by dropping transmissions scheduled at SF #N.
  • the UE performs initial CCA immediately before SF #N and performs extended CCA when the channel is occupied. If the extended CCA ends before the SF # N + 1 boundary, the UE drops the UL signal transmission scheduled in SF #N and performs the initial CCA just before the SF # N + 1 boundary. At this time, as a result of the initial CCA performed just before the SF # N + 1 boundary, if the corresponding channel is occupied again, the terminal performs extended CCA again.
  • the UE drops the UL signal transmission scheduled in SF # N + 1 and performs CCA just before the SF # N + 2 boundary.
  • the UE configures and transmits a TX burst for 1 SF, and in SF # N + 2, at least one OFDM symbol may be left blank for a CCA gap.
  • 19 is another diagram for describing a method of performing extended CCA.
  • the terminal performs initial CCA immediately before SF #N, and performs extended CCA when the channel is occupied.
  • the extended CCA may end between the SF # N + 1 boundary and the SF # N + 2 boundary.
  • the UE may drop all data transmissions scheduled for SF #N and SF # N + 1, and may perform initial CCA immediately before the SF # N + 2 boundary.
  • the UE configures and transmits a TX burst for 1 SF, and in SF # N + 2, at least one OFDM symbol may be left blank for a CCA gap.
  • the terminal performs initial CCA immediately before SF #N, and performs extended CCA when the channel is occupied. If the extended CCA ends just before the SF # N + 1 boundary, the UE drops the UL signal scheduled in SF #N but transmits the UL signal scheduled in SF # N + 1. In this case, the UE configures and transmits a TX burst for 2 SF, and in SF # N + 2, at least one OFDM symbol may be empty for the CCA gap.
  • the UE may transmit a reservation signal and then start transmitting TX bursts from the next SF boundary (ie, SF # N + 1).
  • the T1 value may be a predetermined value or a fixed value on the system through higher layer signaling (eg, an RRC signal).
  • the T1 value may mean a difference between the end of the extended CCA and the start of the CCA slot of the next SF boundary.
  • the corresponding UE performs extended CCA. If the difference between the end of the extended CCA and the SF # N + 1 boundary time is less than or equal to T1, the UE may drop the scheduled data transmission to the SF #N and transmit a reservation signal for the T1 time. The UE then configures and transmits a TX burst for 2 SF (for example, SF # N + 1 and SF # N + 2), and in SF # N + 2, at least one OFDM symbol is configured to configure a CCA gap. It can be left blank.
  • 2 SF for example, SF # N + 1 and SF # N + 2
  • the terminal may be configured to always perform the initial CCA and / or extended CCA before the SF boundary.
  • Such embodiments have the following characteristics.
  • the terminal performs an "initial CCA" T2 hours before every SF boundary.
  • the T2 time may be a preset value, a semi-statically set value through an upper layer signal, or a dynamically set value through a physical layer signal.
  • the UE transmits a reservation signal when the initial CCA resultant channel is in an unoccupied state and then transmits from the next SF boundary.
  • the UE performs "expanded CCA" when the initial CCA resultant channel is occupied or when the Tx burst transmission is completed.
  • the UE may transmit a reservation signal and then perform UL signal transmission from the next SF boundary.
  • the UE may drop the data transmission or postpone to the next SF in the SF (s) that partially overlap with the interval in which the extended CCA is performed.
  • 20 is a view for explaining a modification of the extended CCA execution method.
  • a LAA terminal allocated with 3 consecutive SFs performs initial CCA at a time point T2 hours ahead of SF #N. If the channel is occupied, the terminal performs extended CCA. If the difference between the extended CCA and the SF # N boundary time is less than T2, the terminal transmits a reservation signal before the SF #N start point. The UE may then configure and transmit a TX burst for 3 SF (eg, SF #N to SF # N + 2), and may leave at least one OFDM symbol empty for the CCA gap in SF # N + 2. .
  • 3 SF eg, SF #N to SF # N + 2
  • the LBT operation of the terminal described with reference to FIG. 20 may be easily extended to the LBT operations described with reference to FIGS. 18 through 19.
  • the TX burst may be configured with only the same number of SF (s) as fewer or equal to three SFs scheduled due to the UE performing extended CCA.
  • the UE may be configured to configure and transmit a TX burst consisting of 3 SFs, which are always scheduled numbers once transmission starts. For example, even if the UE performs extended CCA in UL signal transmission, the SF is always scheduled without dropping some SF (s) among the scheduled SFs once a transmission opportunity interval (for example, a TxOP interval) is set. You can configure and transmit as many TX bursts.
  • the CCA gap is configured in the last SF of the SF (s) scheduled by the terminal, the TX burst has been described as a basic assumption that the transmission is started at the SF boundary.
  • the CCA gap can be configured at the SF start point and the TX burst can be set to start after the CCA gap and always end at the SF boundary.
  • the LAA terminal may start the PUSCH transmission in the scheduled SFs if the following conditions are satisfied.
  • the UE observes whether the channel is idle for a minimum T3 time immediately before TX burst (ie, PUSCH) transmission. In this case, the UE may perform CCA for a T3 time.
  • the UE may transmit a reservation signal for a maximum T4 time immediately before the TX burst transmission.
  • T3 and T4 may be predetermined values in the system or values set by higher layer signals or physical layer signals.
  • LBT scheme eg, FBE
  • FBE FBE
  • 21 is a diagram for describing methods of performing LBT that does not perform random backoff.
  • the CCA may be performed for a predetermined time immediately before (or immediately after) the starting point. If the UE performs CCA immediately before the starting point of SF # n + k and determines that the corresponding channel is idle, the UE may attempt to transmit a PUSCH in SF # n + k.
  • X may be a preset value or a value set through higher layer signaling.
  • the UE is configured to perform CCA at a CCA timing set at a 4 ms period (for example, immediately before the starting point of SF # n-2, SF # n + 2, SF # n + 6, ). do.
  • the base station may transmit a UL grant for scheduling the SF to the terminal.
  • the UE that has received the UL grant cannot attempt PUSCH transmission at the time point of SF # n + 4 since the CCA timing is not set in SF # n + 4. Accordingly, the UE may attempt to transmit PUSCH when the channel is idle by performing CCA at the closest CCA timing after SF # n + 4.
  • the base station may transmit the UL grant in advance at SF #n, which is the time point when the channel occupies the channel.
  • CCA may be performed in timing.
  • the terminal may attempt to transmit a PUSCH. If the corresponding channel is busy, the UE may perform CCA at the next CCA timing and perform PUSCH transmission if the channel is idle.
  • the scheme described in FIG. 21 (b) may be applied to the case of the UL grant transmission through the cross carrier scheduling as well as the UL grant transmission through the eNB.
  • the embodiments may be applied even when the CCA start timing is set at a predetermined periodic interval.
  • Information indicating whether the above-described embodiments of the present invention is applied (or information on the rules of the proposed methods) is transmitted through a signal (eg, a physical layer signal or a higher layer signal) previously defined by the base station to the terminal. Can be defined to inform.
  • a signal eg, a physical layer signal or a higher layer signal
  • Embodiments of the present invention described below relate to efficient LBT operating methods in communication between an eNB and a UE operating in an unlicensed band.
  • the communication node eg, eNB or UE
  • signals having different lengths of transmission periods may be defined as different types of signals. In this case, signals having different transmission periods may overlap transmission times depending on the transmission type.
  • a signal of a type to be transmitted first may be preset according to the importance of the radio signal.
  • the eNB transmits two different types of signals (for example, type 1 signal and type 2 signal), but there are two or more different types of signals or several types from the UE's point of view. It is also applicable to environments that can transmit signals.
  • no transmitting entity Due to the nature of the unlicensed band, no transmitting entity has the exclusive right to transmit a radio signal in the unlicensed band, so the communication node detects whether there is another node currently transmitting and then transmits the signal before transmitting the radio signal. If it is determined that no other node exists, the transmission can be started. This series of processes is called LBT.
  • the LBT scheme can be divided depending on whether or not a random backoff is used.
  • the random backoff refers to a process in which a communication node selects a random backoff counter value before the start of transmission of a radio signal, and starts the actual transmission when a section in which the channel is determined to be idle by the corresponding counter value is found.
  • the LBT method starts transmission when it is determined that the channel is idle only for a predetermined time interval without a random backoff.
  • the channel is determined to be in an idle state as CCA (Clear Channel Assessment), and the CCA timing at which the CCA is performed is set in advance to a predetermined period value and an offset value.
  • LBT Low-power Bluetooth
  • FIGS. 13 and 14 An example of such an LBT scheme is the FBE under EU regulations.
  • the description of the FBE refers to FIGS. 13 and 14.
  • the LBT parameters such as the cycle value and the offset of the CCA timing are commonly applied parameter values for various types that the eNB should transmit.
  • a communication node eg, a base station or a terminal
  • a communication node may be configured to use a common LBT scheme in transmitting several different types of signals. If there is a type 1 signal and a type 2 signal, an LBT scheme in which a communication node performs CCA with a period of X ms in common in transmitting two types of signals may be used. For example, the transmission period of the type 1 signal and the transmission period of the type 2 signal may be set to be multiples of X.
  • methods of setting common parameters for performing LBT will be described.
  • FIG. 22 is a diagram for describing FBE-based LBT performing methods without random backoff.
  • the eNB when an eNB configured to start DL signal transmission when a channel is idle by performing a CCA every 4 ms, the eNB attempts to transmit a type 1 signal every 4 ms.
  • FIG. 22C illustrates a method of setting LBT parameters (for example, CCA timing periods and offset values) capable of transmitting both type 1 and type 2 signals in order to solve this problem.
  • LBT parameters for example, CCA timing periods and offset values
  • the period value of the CCA timing may be set to one of the common factors of X and Y.
  • the base station can always attempt to transmit Type 1 and Type 2 signals.
  • the base station may perform the CCA at the time point SF #N + 6. Accordingly, the base station may transmit a type 2 signal when the U cell is idle. That is, the base station may attempt to transmit the corresponding signal when the channel is idle by performing the CCA only before transmitting the type 1 or type 2 signal among the set CCA timings.
  • the base station transmits a type 2 signal having a higher priority among type 1 and type 2 signals when the CCA result is idle in the SF #N and # N + 12, and the CCA in the SF # N + 2 and SF # N + 10. Timing does not perform CCA because no signal is set to transmit.
  • the base station may perform the CCA in the SF #N + 4, #N + 6 and #N + 8 that do not overlap the transmission period of the type 1 signal and the type 2 signal may transmit a signal of the type according to each transmission period.
  • the period is not set in advance for all types of signals like the methods described in Section 4.6.1, the period is fixed only for one type of signal and the period of the other types of signals is configurable. Methods of setting an LBT parameter (eg, a period of CCA timing and an offset value, etc.) will be described.
  • the period of the type 1 signal and the period of the CCA timing may be set to one of the factors of Z.
  • the period of the type 2 signal is set to 40 ms, and the priority of the type 2 signal is higher than that of the type 1 signal.
  • the period of the type 1 signal and the period of the CCA timing may be set to one of 40, 20, 10, 8, 5, 4, 2, and 1 which is a divisor of Z.
  • the CCA may be performed every 4 ms for the type 1 signal transmission, and the CCA for the type 2 signal transmission may be performed every 40 ms.
  • the base station occupies a channel once to start transmitting the type 2 signal, there may be a constraint that the base station should attempt to transmit the type 2 signal during the W ms period.
  • the period of the type 1 signal and the period of the CCA timing may be set to a value greater than or equal to W in the divisor of X.
  • FIG. 23 is a diagram for describing a method of setting common parameters for LBT.
  • the period of the CCA timing is set to 4 ms, since the base station can not perform the CCA due to the transmission of the type 2 signal at the beginning of SF #N + 4, the transmission of the type 1 signal only at the time of SF # N + 8 You can try To solve this problem, if the period of the CCA timing is set to one of 40, 20, 10, 8, and 5, which is greater than 5, the base station can prevent the type 1 signal transmission from being delayed due to the type 2 signal transmission. have.
  • the transmission period of the type 1 signal is set to Z ′ ms in advance, and the transmission period of the type 2 signal and the period of the CCA timing may be set to one of multiples of Z ′.
  • the period of the type 2 signal and the period of the CCA timing are 5, 10, 15, 20,... It can be set to one of these values.
  • the base station may perform CCA every 5 ms for the type 1 signal transmission, and perform CCA for the type 2 signal transmission every 20 ms.
  • Information on whether the above-described embodiments of the present invention are applied (or information on the rules of the proposed methods) may be transmitted to the base station through a predefined signal (eg, a physical layer signal or a higher layer signal).
  • a predefined signal eg, a physical layer signal or a higher layer signal.
  • FIG. 24 is a diagram for explaining an FBE-like LBE based LBT execution method described in Sections 4.1 to 4.4 from a UE perspective.
  • the terminal may receive a UL grant for scheduling a U cell from a base station.
  • the UL grant may be transmitted in a self carrier scheduling method or a cross carrier scheduling method.
  • the UE may be scheduled for two or more consecutive subframes (S2410).
  • the terminal may determine whether the radio channel is idle (ie, not occupied) in the corresponding SF immediately before the boundary of the scheduled subframe or at a predetermined time (for example, T2 or T3 time). LBT) may be performed (S2420).
  • the initial CCA performed in step S2420 may refer to a process of checking one channel state without a random backoff. That is, the UE does not perform several CCAs and immediately transmits a TX burst (for example, UL signal), performs extended CCA, or drops UL signal transmission according to the state of the channel after performing one CCA. can do.
  • a TX burst for example, UL signal
  • the terminal may determine whether the corresponding wireless channel is in an idle state or busy state based on the initial CCA result (S2430).
  • the terminal may perform extended CCA (or LBT) without transmitting UL signals (S2440).
  • the extended CCA is a concept including a method of performing a CCA until a counter value becomes '0' by extracting a random random backoff counter value, or a method of continuously performing a CCA for a predetermined period.
  • the reason for performing the extended CCA is to determine whether the channel occupancy state is temporary or continuous, and when the terminal occupies the channel occupancy state at the timing of transmitting the TX burst, the UE changes to idle after a short time. To do this.
  • the terminal may determine whether the corresponding channel is busy or idle by performing extended CCA (S2450).
  • the UE may drop the TX burst transmission in the corresponding SF and perform the initial CCA again in the next SF.
  • step S2430 and step S2450 if the channel is idle, the terminal may transmit a TX burst (S2460).
  • Methods of performing initial CCA and extended CCA in steps S2420 and S2450 and methods of transmitting a TX burst in step S2460 may be applied to the methods described in Sections 4.1 to 4.4 described above.
  • the UE may drop the TX burst transmission and attempt the TX burst transmission in the next SF. In this case, the UE may prepare for a hidden node problem by transmitting a reservation signal until the next SF.
  • FIG. 25 is a means by which the methods described with reference to FIGS. 1 to 24 may be implemented.
  • a UE may operate as a transmitting end in uplink and a receiving end in downlink.
  • an e-Node B eNB
  • eNB e-Node B
  • the terminal and the base station may include transmitters 2540 and 2550 and receivers 2550 and 2570, respectively, for controlling the transmission and reception of information, data and / or messages.
  • the antenna may include antennas 2500 and 2510 for transmitting and receiving messages.
  • the terminal and the base station may each include a processor 2520 and 2530 for performing the above-described embodiments of the present invention, and memories 2580 and 2590 that can temporarily or continuously store the processing of the processor. Can be.
  • Embodiments of the present invention can be performed using the components and functions of the above-described terminal and base station apparatus.
  • a processor of a terminal may perform an initial CCA (or initial LBT) and / or an extended CCA (or extended LBT) by controlling a transmitter and / or a receiver to transmit a TX burst in a scheduled serving cell. have. If the channel is in the idle state, the processor of the terminal may transmit a TX burst (eg, an UL signal) in the scheduled SF by controlling the transmitter.
  • a TX burst eg, an UL signal
  • Detailed embodiments may refer to the above-described sections 1 to 4.
  • the transmitter and the receiver included in the terminal and the base station include a packet modulation and demodulation function, a high speed packet channel coding function, an orthogonal frequency division multiple access (OFDMA) packet scheduling, and a time division duplex (TDD) for data transmission. Packet scheduling and / or channel multiplexing may be performed.
  • the terminal and the base station of FIG. 19 may further include a low power radio frequency (RF) / intermediate frequency (IF) unit.
  • RF radio frequency
  • IF intermediate frequency
  • the terminal is a personal digital assistant (PDA), a cellular phone, a personal communication service (PCS) phone, a GSM (Global System for Mobile) phone, a WCDMA (Wideband CDMA) phone, an MBS.
  • PDA personal digital assistant
  • PCS personal communication service
  • GSM Global System for Mobile
  • WCDMA Wideband CDMA
  • MBS Multi Mode-Multi Band
  • a smart phone is a terminal that combines the advantages of a mobile communication terminal and a personal portable terminal, and may mean a terminal incorporating data communication functions such as schedule management, fax transmission and reception, which are functions of a personal mobile terminal, in a mobile communication terminal.
  • a multimode multiband terminal can be equipped with a multi-modem chip to operate in both portable Internet systems and other mobile communication systems (e.g., code division multiple access (CDMA) 2000 systems, wideband CDMA (WCDMA) systems, etc.). Speak the terminal.
  • CDMA code division multiple access
  • WCDMA wideband CDMA
  • Embodiments of the invention may be implemented through various means.
  • embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.
  • the method according to embodiments of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs). Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.
  • ASICs application specific integrated circuits
  • DSPs digital signal processors
  • DSPDs digital signal processing devices
  • PLDs programmable logic devices
  • FPGAs Field programmable gate arrays
  • processors controllers, microcontrollers, microprocessors, and the like.
  • the method according to the embodiments of the present invention may be implemented in the form of a module, a procedure, or a function that performs the functions or operations described above.
  • software code may be stored in the memory units 2480 and 2490 and driven by the processors 2420 and 2430.
  • the memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.
  • Embodiments of the present invention can be applied to various wireless access systems.
  • various radio access systems include 3rd Generation Partnership Project (3GPP), 3GPP2 and / or IEEE 802.xx (Institute of Electrical and Electronic Engineers 802) systems.
  • Embodiments of the present invention can be applied not only to the various radio access systems, but also to all technical fields to which the various radio access systems are applied.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente invention concerne un système d'accès sans fil prenant en charge une bande sans licence et des procédés d'exécution d'une opération LBT pour exécuter une détection de porteuse efficace. L'invention concerne également des appareils prenant en charge le procédé. Selon un mode de réalisation de la présente invention, un procédé d'exécution, par un terminal dans un système d'accès sans fil prenant en charge une bande sans licence, d'une opération LBT en vue de transmettre un signal de liaison montante, comprend les étapes dans lesquelles : le terminal exécute une LBT initiale dans une cellule de bande sans licence (UCell); et le terminal exécute une LBT étendue si la UCell est dans un état occupé après exécution de la LBT initiale; et le terminal transmet le signal de liaison montante si la UCell est dans un état de veille après exécution de la LBT initiale. Le procédé peut comprendre en outre une étape dans laquelle le terminal transmet le signal de liaison montante si la UCell est dans un état de veille après exécution de la LBT étendue.
PCT/KR2016/001003 2015-02-01 2016-01-29 Procédé d'exécution de lbt dans un système d'accès sans fil prenant en charge une bande sans licence, et appareil prenant en charge le procédé Ceased WO2016122249A2 (fr)

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US201562110591P 2015-02-01 2015-02-01
US62/110,591 2015-02-01
US201562132512P 2015-03-13 2015-03-13
US62/132,512 2015-03-13
US201562136384P 2015-03-20 2015-03-20
US62/136,384 2015-03-20
US201562161229P 2015-05-13 2015-05-13
US62/161,229 2015-05-13

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018185641A1 (fr) * 2017-04-03 2018-10-11 Telefonaktiebolaget L M Ericsson (Publ) Départ dynamique pour transmission sur un spectre sans licence
CN109309961A (zh) * 2017-07-28 2019-02-05 华为技术有限公司 一种配置随机接入的方法、网络设备及终端设备
WO2019217629A1 (fr) * 2018-05-11 2019-11-14 Qualcomm Incorporated Conception de canal partagé autour de ressources réservées
CN111224713A (zh) * 2020-01-13 2020-06-02 力同科技股份有限公司 通信终端在时分多址直通模式中的信号发射方法
US12432772B2 (en) 2018-08-03 2025-09-30 Samsung Electronics Co., Ltd. Method and apparatus for indicating channel occupancy time in wireless communication system

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Publication number Priority date Publication date Assignee Title
US10314077B2 (en) * 2013-05-20 2019-06-04 Qualcomm Incorporated Gating scheme for wireless communication over unlicensed spectrum

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018185641A1 (fr) * 2017-04-03 2018-10-11 Telefonaktiebolaget L M Ericsson (Publ) Départ dynamique pour transmission sur un spectre sans licence
US11363631B2 (en) 2017-04-03 2022-06-14 Telefonaktiebolaget Lm Ericsson (Publ) Dynamic start for transmission on unlicensed spectrum
CN109309961A (zh) * 2017-07-28 2019-02-05 华为技术有限公司 一种配置随机接入的方法、网络设备及终端设备
CN109309961B (zh) * 2017-07-28 2023-06-02 华为技术有限公司 一种配置随机接入的方法、网络设备及终端设备
WO2019217629A1 (fr) * 2018-05-11 2019-11-14 Qualcomm Incorporated Conception de canal partagé autour de ressources réservées
CN112119604A (zh) * 2018-05-11 2020-12-22 高通股份有限公司 围绕所保留资源的共享信道设计
US11129196B2 (en) 2018-05-11 2021-09-21 Qualcomm Incorporated Shared channel design around reserved resources
US11570815B2 (en) 2018-05-11 2023-01-31 Qualcomm Incorporated Shared channel design around reserved resources
CN112119604B (zh) * 2018-05-11 2023-08-22 高通股份有限公司 围绕所保留资源的共享信道设计
US12432772B2 (en) 2018-08-03 2025-09-30 Samsung Electronics Co., Ltd. Method and apparatus for indicating channel occupancy time in wireless communication system
CN111224713A (zh) * 2020-01-13 2020-06-02 力同科技股份有限公司 通信终端在时分多址直通模式中的信号发射方法
CN111224713B (zh) * 2020-01-13 2023-02-03 力同科技股份有限公司 通信终端在时分多址直通模式中的信号发射方法

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