WO2017200112A1 - Procédé et appareil de signalisation pour exécuter un processus de découverte dans un système d'accès sans fil prenant en charge des ondes millimétriques - Google Patents

Procédé et appareil de signalisation pour exécuter un processus de découverte dans un système d'accès sans fil prenant en charge des ondes millimétriques Download PDF

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WO2017200112A1
WO2017200112A1 PCT/KR2016/005149 KR2016005149W WO2017200112A1 WO 2017200112 A1 WO2017200112 A1 WO 2017200112A1 KR 2016005149 W KR2016005149 W KR 2016005149W WO 2017200112 A1 WO2017200112 A1 WO 2017200112A1
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mmwave
discovery
base station
terminal
transmitted
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PCT/KR2016/005149
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English (en)
Korean (ko)
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최국헌
고현수
노광석
김동규
이상림
이호재
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엘지전자 주식회사
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Priority to PCT/KR2016/005149 priority Critical patent/WO2017200112A1/fr
Publication of WO2017200112A1 publication Critical patent/WO2017200112A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/28—Cell structures using beam steering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/32—Hierarchical cell structures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/16—Discovering, processing access restriction or access information

Definitions

  • the present invention relates to a wireless access system supporting millimeter wave (mmWave), and to signaling methods for performing a discovery process performed in an mmWave cell and apparatuses for supporting the same.
  • mmWave millimeter wave
  • 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 support efficient data communication in the mmWave system.
  • Another object of the present invention is to provide a method for performing a discovery process in an mmWave system.
  • Yet another object of the present invention is to provide an apparatus for supporting such methods.
  • the present invention relates to a wireless access system supporting millimeter wave (mmWave), and to signaling methods for performing a discovery process performed in an mmWave cell and apparatuses for supporting the same.
  • mmWave millimeter wave
  • a method for supporting the mmWave discovery process in a wireless access system supporting millimeter wave may be performed by the mmWave terminal transmitting a discovery trigger feedback signal for requesting the start of mmWave discovery when the quality of the mmWave link is degraded. And receiving, by the mmWave terminal, the mmWave discovery signal in a subframe indicated by the discovery subframe index.
  • the discovery trigger feedback signal may include a discovery subframe index indicating a subframe in which the mmWave discovery signal is to be transmitted.
  • the mmWave terminal supporting the mmWave discovery process in a wireless access system supporting millimeter wave may include a transmitter, a receiver, and a processor for supporting the mmWave discovery process.
  • the processor when the quality of the mmWave link is degraded, the processor is configured to transmit a discovery trigger feedback signal for requesting the start of mmWave discovery by controlling the transmitter and control the receiver in a subframe indicated by the discovery subframe index to receive the mmWave discovery signal.
  • the discovery trigger feedback signal may include a discovery subframe index indicating a subframe in which the mmWave discovery signal is to be transmitted.
  • the discovery subframe index may be set in consideration of the beam gain, the beam width of the first mmWave base station to which the mmWave link is connected, and the number of mmWave cells configured in the first mmWave base station.
  • the discovery trigger feedback signal may be transmitted to the first mmWave base station.
  • the discovery trigger feedback signal may be transmitted to a second mmWave base station that has established an mmWave link different from the mmWave terminal other than the first mmWave base station.
  • the discovery trigger feedback signal may further include a base station identifier indicating the first mmWave base station.
  • the discovery trigger feedback signal may be periodically transmitted through the periodically allocated mmWave uplink resource.
  • mmWave discovery can be performed quickly to ensure more reliable transmission of mmWave data.
  • the discovery process may be efficiently performed by transmitting a discovery trigger feedback signal or a discovery trigger indication signal for performing mmWave discovery to an mmWave cell to which a stable link is connected.
  • 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 an antenna port used in mmWave.
  • FIG. 7 is a diagram illustrating an example of a cell radius that can be covered by the omnidirectional antenna and the directional antenna.
  • FIG. 8 is a diagram illustrating an example of an initial stage of receive beam scanning for transmit beam scanning.
  • FIG. 9 is a diagram illustrating one of methods for performing beam scanning at a transmitting end after a receiving lobe index is fixed at a receiving side.
  • FIG. 10 is a diagram for describing a discovery measurement timing configuration.
  • FIG. 11 is a view for explaining the mmWave small cell structure.
  • FIG. 12 is a view for explaining the mmWave cell structure in analog beamforming.
  • FIG. 13 is a diagram illustrating a distribution state and an mmWave cell configuration in each cell of mmWave terminals in one mmWave base station.
  • 14 is a diagram for explaining link instability due to link blocking and the necessity of performing an mmWave discovery process.
  • FIG. 15 is a diagram illustrating a method of performing an mmWwave cell discovery process at the request of an mmWave terminal.
  • FIG. 16 illustrates a process of performing an mmWave cell discovery process according to a determination of an mmWave base station.
  • FIG. 17 illustrates a method of performing an mmWave cell discovery process in response to a request of an mmWave terminal in a multi-cell arrangement.
  • FIG. 18 is a diagram illustrating a process of performing an mmWave cell discovery process according to a determination of an mmWave base station in a multi-cell deployment environment.
  • FIG. 19 illustrates one method of transmitting an mmWave discovery trigger feedback signal.
  • FIG. 20 is a diagram for describing a method of transmitting a discovery trigger indication signal at a transmission timing of all mmWave cells according to UE performance for all mmWave cells configured together in one mmWave base station.
  • FIG. 21 is a diagram for describing a method of periodically transmitting a discovery trigger feedback signal according to an uplink transmission timing period set according to mmWave system information.
  • the apparatus described in FIG. 22 is a means in which the methods described in FIGS. 1 to 21 can be implemented.
  • 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.
  • 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.
  • 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.
  • k floor ( / 2), and 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.
  • the present invention relates to a method for transmitting and receiving signals for detecting site specific ray characteristic information and rich resolvable ray detection, and devices supporting the mmWave link. Due to the existing short mmWave cell range, performing beamforming is essential for antenna beam gain of a transmit / receive antenna. Accordingly, beamforming-based beam scanning techniques have been proposed as mmWave scanning techniques. However, these techniques have a disadvantage in that transmission and reception scanning delay is long due to the overhead of beam scanning.
  • the ray scanning technique proposed in the present invention is effective in reducing a large overhead due to the beam scanning technique by detecting inherent characteristics of the mmWave environment.
  • the information due to the transmission and reception beam scanning of the terminal is not the characteristic information of the channel (for example, power delay profile (PDP) or power azimuth spectrum (PAS), etc.), so it is used for channel-specific information acquisition and application can do.
  • PDP power delay profile
  • PAS power azimuth spectrum
  • FIG. 6 is a diagram illustrating an example of an antenna port used in mmWave.
  • Antenna ports are a virtual concept of physical antennas.
  • the output sent to the antenna port necessarily includes a reference signal (RS).
  • RS reference signal
  • the output to one logical antenna port can be viewed in units of antenna streams, including the RS, in which the terminal can detect and estimate the channel by receiving the RS.
  • the terminal may transmit one antenna port. Can be assumed to be received.
  • the physical antenna is composed of a separate mapping from the antenna port, and the mapping between the physical antenna and the antenna port is determined according to a vendor. Therefore, techniques for transmitting signals or data per antenna port have been considered without considering the problem of implementing the physical antenna.
  • the term cell search is a collective term meaning a combination of measurement and evaluation detection processes. Since the cell search is the first step performed before the terminal performs cell selection, it is very closely related to the cell selection process. In addition, the cell search process has a great influence on the energy consumption of the terminal in the idle mode.
  • the DRX cycle is a kind of timer.
  • the measurement / evaluation / detection process is performed for a period specified as the number of DRX cycles.
  • the DRX cycle is determined from the network via a SIB1 message.
  • 'scan' is not explicitly defined in the specification documents, but most terminals perform this process. This is a tuning process for a particular frequency and is the simplest signal quality (eg RSSI) measurement procedure. Usually, before the measurement and evaluation process, the UE performs a scanning process first and selects a small number of candidates to perform the following process (eg, measurement and evaluation). If the terminal directly measures and evaluates all possible frequencies and bands, the terminal suffers from too much time and serious power consumption.
  • RSSI signal quality
  • the 'Measurement' is the process of measuring RSRP and RSRQ. All non-serving cell measurements are performed as defined in 36.133 of the LTE / LTE-A specification.
  • the "evaluation” process is a process for identifying cell selection criteria based on the results of the "measurement” process.
  • the 'detection' process is a process of tuning and synchronizing a specific frequency and decoding basic information of cells.
  • the WCDMA system is an earlier version of the LTE / LTE-A system, and the following description is also applicable to the LTE / LTE-A system.
  • the terminal When the terminal is powered on for the first time or the terminal is out of cell coverage, the terminal performs detection and search for a new cell. Since the UE does not know which cell of which cell to camp on, it should perform blind decoding. For example, it is assumed that the terminal supports WCDMA band I. In this case, the base station near the terminal may use the frequency channels 10562 to 10838. That is, the terminal may use 276 possible frequencies.
  • the UE first measures the RSSI for each of the supported channels.
  • RSSI is a measurement value that can be measured by the terminal for any energy / power.
  • RSSI measurement does not require a channel coding process.
  • the terminal does not need to know anything about the network. That is, the terminal does not need to decode the synchronization / reference signal in the PCPICH in the WCDMA system and the LTE system in order to detect the physical cell identifier.
  • the terminal only needs to measure the power of each channel.
  • the terminal may generate a list of channel numbers with the measured RSSI.
  • the terminal distinguishes channels whose RSSI is higher than a threshold by using a list of generated channel numbers. Then, the terminal performs the following steps to find a suitable candidate to camp on.
  • the terminal decodes the PCPICH or synchronization / reference signal to detect the physical cell identifier and measures power.
  • the terminal creates a candidate cell list with respect to the detected physical cell identifiers.
  • the terminal decodes the MIB for all candidate cells.
  • the terminal Based on the sentiment information and the candidate cell list, the terminal identifies which cell is the most suitable cell to camp on, and performs system information and registration process.
  • FIG. 7 is a diagram illustrating an example of a cell radius that can be covered by the omnidirectional antenna and the directional antenna.
  • the range of cells covered by the omnidirectional antenna is wider than the range of cells covered by the directional antenna.
  • the directional antenna is used in mmWave, that is, when beamforming is used, the range gain of the beamforming is reduced by about -20 dB. Therefore, it is preferable to use an omnidirectional antenna, but in the case of mmWave, there is a problem in that channel characteristics change rapidly according to a user position.
  • the present invention overcomes this problem and proposes methods for increasing the cell range that can be covered by an omnidirectional antenna up to the range covered by the directional antenna.
  • FIG. 8 is a diagram illustrating an example of an initial stage of reception beam scanning for transmission beam scanning
  • FIG. 9 is a diagram illustrating one of methods of performing beam scanning at a transmitting end after a reception lobe index is fixed at a reception side.
  • the transmission beam is fixed and the receiving side, i.e., the terminal, rotates the reception beam scanning 360 degrees to derive a PDP (Power Delay Prifile) for each beam.
  • the terminal selects an index of a reception lobe having a ray having the largest power among the detected PDPs.
  • the lobe refers to each radiation group when the energy distribution of the radio waves radiated from the antenna is divided in various directions. That is, it means one type of beam during beam scanning.
  • Equation 3 is used to calculate the SNR of each lobe detected by the UE.
  • Equation (3) Denotes the radio channel of the i th lobe for the transmit beam k, wi denotes the precoding matrix, pi denotes the received power, sigma ( ⁇ ) is the magnitude of the noise, and sigma is the noise Means power.
  • the time at which reception beam scanning for the fixed transmission beam lobe is completed is completed.
  • the value may be determined as in Equation 4 below.
  • the receiver repeats the above process, varying the entire transmission beam lobe of 360 to 360 degrees. Therefore, the beam scanning completion time of the receiver is to be.
  • K means the total number of transmission beams.
  • the terminal which is a receiving terminal, completes beam scanning, transmits a pilot signal to the mmWave base station again. Thereafter, the terminal performs 360 degree beam scanning to determine the transmission side lobe index. Therefore, the time when the transmission and reception beam scanning is completed Obviously, the time when the transmission and reception beam scanning is completed Obviously, the time when the transmission and reception beam scanning is completed Obviously, the time when the transmission and reception beam scanning is completed Obviously, the time when the transmission and reception beam scanning is completed Becomes
  • Table 6 below defines the parameters for measuring the beam scanning completion time.
  • the channel instead of the approximate beam scanning is used.
  • Ray scanning may be performed to obtain unique information.
  • the mmWave terminal may obtain candidate precision beam vectors using channel specific information obtained through ray scanning to reduce beam scanning overhead and reduce overall scanning time.
  • the mmWave base station transmits a time / frequency synchronization signal to synchronize time and frequency synchronization with the mmWave terminal.
  • the mmWave base station also transmits different pilot signals to perform ray scanning per cell specific port. In this case, different pilot signals per cell specific port may be repeatedly transmitted or may be transmitted with a certain period.
  • the receiving terminal performs post-processing and ray scanning per cell-specific port based on the received pilot signal.
  • the terminal determines one or more candidate beam vector sets to determine a beamforming port for beamforming to be performed in hybrid scanning. Thereafter, the terminal may perform selective beam scanning for each base station and beamforming port.
  • the terminal may transmit a pilot signal to the base station using the selected beamforming port.
  • the base station may perform selective beam scanning by detecting a pilot signal transmitted for each candidate beamforming port transmitted by the terminal.
  • the base station and / or the terminal may perform ray scanning and beam scanning together.
  • the base station and / or the terminal transmits and receives a pilot signal for performing ray scanning, performs ray scanning using a pilot signal, obtains candidate beam vector sets, and beam scans within candidate beam vector sets. Can be performed.
  • the base station may inform each terminal of a pilot index and a resource pool index to be transmitted from the terminal to the base station.
  • the pilot index and the resource pool index are transmitted to the respective UEs for performing ray scanning
  • the pilot index and the resource to which the pilot signal and the corresponding pilot signal are transmitted are multiplexed by the CDM method to the pilot signals per cell specific port. Indicate the location.
  • mmWave cells may be composed of multiple virtual cells. Accordingly, data transmission timing for mmWave terminals may be set differently in each virtual cell.
  • Embodiments of the present invention relate to resource allocation methods for mmWave terminals distributed at different densities within mmWave virtual cells managed by one or more mmWave base stations.
  • the base station controlling the mmWave link may be called an mmWave base station, and the base station controlling the legacy link may be called a legacy base station.
  • the base station may configure and manage both the mmWave link and the legacy link (eg, the link of the LTE / LTE-A system).
  • FIG. 10 is a diagram for describing a discovery measurement timing configuration.
  • DMTC Discovery Measurement Timing Configuration
  • the terminal or mmWave terminal and the base station (or mmWave base station) may be performed in an RRC connected state.
  • DMTC is performed based on Network Assitance.
  • the measurement timing information is transmitted to the terminal and the DRS is discontinuously transmitted.
  • the base station transmits a synchronization signal or reference signals (for example, PSS / SSS, CRS, CSI-RS) to the terminal, the terminal based on the received synchronization signal or reference signals RSRP (Reference Signal Received Power) And RSRQ (Reference Signal Received Quality).
  • a synchronization signal or reference signals for example, PSS / SSS, CRS, CSI-RS
  • RSRP Reference Signal Received Power
  • RSRQ Reference Signal Received Quality
  • the legacy DMTC is performed in a cycle of 40, 80, or 160 ms units.
  • one DMTC interval is composed of 1 ⁇ 5ms, the terminal measures the discovery signal transmitted from each small cell in the corresponding DMTC interval.
  • the DMTC interval has an offset of 0 to 1 in the PCell subframe or system frame index and may be fixed to a length of 6 ms.
  • FIG. 11 is a view for explaining the mmWave small cell structure.
  • the mmWave link has very high link instability caused by causes such as a transition between Line of Sight / Non-Line of Sight, human obstacles, and / or human body impact of the receiving user. Therefore, it is desirable for mmWave base stations to support multiple link transmission by more densely placing than existing small cells.
  • the outermost large boundary is the legacy small cell
  • the intermediate boundary is the mmWave small cell in which beamforming is performed. It is the small cell in the NLoS state that has the smallest cell boundary. That is, the mmWave small cell has a denser cell arrangement structure than the existing small cell.
  • FIG. 12 is a view for explaining the mmWave cell structure in analog beamforming.
  • FIG. 12 (a) shows the appearance of an omni mmWave cell
  • FIG. 12 (b) shows the appearance of a directional mmWave cell.
  • the base station has a short omni cell range due to the limitation of path loss (PL). Therefore, in order to overcome this disadvantage, the mmWave system considers beamforming to extend the propagation reach through beam gain and to increase throughput through spatial reuse of directional antennas.
  • PL path loss
  • the mmWave's short wavelength length also facilitates the on-chip hardware design of large scale array antennas, so mmWave cells are collocated on a beamforming basis. Appear as multiple cells
  • FIG. 13 is a diagram illustrating a distribution state and an mmWave cell configuration in each cell of mmWave terminals in one mmWave base station.
  • the mmWave cells in one mmWave base station may be configured according to the beamforming capability of the base station.
  • the shape of the mmWave cell is composed of a plurality of mmWave cells of various sizes and shapes.
  • an mmWave base station with 90 degrees of capability on an analog beam as shown in FIG. 13 (a) has a geometry of 7 (eg omni cell and 6 directional cells) relative to the 3D omni cell radius.
  • Base cells may be configured in one mmWave base station.
  • a user UE 01 may be connected to a mmWave base station in an omni cell, but may not be connected in beamforming in one direction (ie, with another mmWave cell). That is, in the transmission analog beamforming, it is determined whether or not a link for the user is connected according to the transmission beam configuration in the mmWave cell and the reception beam configuration in the mmWave terminal.
  • the receive beam configuration is preferably considered by tying mmWave terminals located in distinct mmWave cells of the mmWave base station.
  • the mmWave base station can broadcast cell specific transmission configuration information for a terminal group in each mmWave cell and mmWave system information for mmWave users in each group.
  • cell specific transmission configuration information and / or mmWave system information may be transmitted to mmWave terminals in advance through the legacy system.
  • a configuration in which UE-specific transmission is performed in each mmWave cell is required.
  • FIG. 13B illustrates a case in which resource allocation for each mmWave cell is performed by the TDM scheme.
  • resource allocation for the mmWave cell may be performed on the time axis in a TDM manner, but may be separately performed for the omni cell and the directional cell.
  • SF # 0 may be allocated resources for mmWave omni cells
  • SF # 2 to # 7 may be allocated resources for mmWave directional cells.
  • 14 is a diagram for explaining link instability due to link blocking and the necessity of performing an mmWave discovery process.
  • the first purpose for performing the mmWave discovery process is to find an mmWave cell having the best link at the time of initial access, and to synchronize the cell by connecting to the mmWave cell.
  • the second purpose is for the mmWave terminal to find an mmWave cell having a better link when the received signal from the current serving cell is not good.
  • the most important factor for the mmWave discovery process is how many candidate cells can receive the received signal power for each mmWave terminal when performing the mmWave discovery process.
  • FIG. 14 (a) shows a case in which a mmWave terminal is connected to a mmWave BS1 in a case where a LoS link can be established with three mmWave base stations. Transition to NLoS indicates that the link is unstable. As such, in the mmWave system, an unexpected sudden LoS / NLoS transition can occur frequently due to the directional characteristics and directivity of the mmWave cells, the transmission configuration of the mmWave system, the blocking of moving obstacles and obstacles due to movement, and the user's own link blocking. .
  • an mmWave terminal that had a good RSRP may suddenly have a bad RSRP. More specifically, in the mmWave band transmission, the quality of a link transmitting a signal may suddenly degrade due to a beamforming mismatch or an element blocking a signal.
  • the link has a bad RSRP, it is necessary to perform an optimal rerouting of the link to the mmWave terminal among multiple cells co-located in one mmWave BS. In other words, an mmWave discovery process is needed to find mmWave cells for repairing or replacing a suddenly degraded link.
  • the existing UE-specific cell discovery signal it is configured to discover a cell by setting periodic time intervals and resources for each UE.
  • embodiments of the present invention described below are related to a method in which an mmWave terminal requests mmWave cell discovery from a base station after RSRP measurement to perform mmWave cell discovery. That is, below, the mmWave terminal may measure and determine the sudden link degradation of the mmWave cell, and transmit a discovery trigger feedback message for performing the discovery process to the base station.
  • FIG. 15 is a diagram illustrating a method of performing an mmWwave cell discovery process at the request of an mmWave terminal.
  • FIG. 15 (a) shows how signaling is transmitted and received in terms of mmWave uplink and downlink when the mmWave system is configured in a frame or subframe structure
  • FIG. 15 (b) shows how the discovery subframe index K is set. It is shown to illustrate.
  • the mmWave terminal can determine the situation where the link suddenly degraded by measuring the RSRP for the mmWave base station.
  • the mmWave terminal may transmit a discovery trigger feedback signal for requesting the start of the mmWave cell discovery process to the mmWave base station through the mmWave uplink (S1510).
  • the discovery trigger feedback signal may include triggering flag and discovery subframe index information.
  • the triggering flag is a bit indicating whether the mmWave discovery process is enabled or disabled (discovery triggering enable / disable bit), indicating whether to perform the discovery process or not.
  • the discovery subframe index information is used to indicate timing information for the mmWave terminal to perform mmWave discovery signal measurement.
  • Table 7 below shows an example of a discovery subframe index.
  • the mmWave base station may determine when to transmit the mmWave discovery signal to the terminal with reference to the discovery subframe index.
  • the mmWave terminal may also know the subframe / frame timing for measuring the mmWave discovery signal to be transmitted from the base station based on the discovery subframe index.
  • the discovery subframe index directly indicates the subframe / frame index to which the mmWave discovery signal is transmitted or the number of frames / subframes corresponding to the timing at which the discovery signal is transmitted after discovery triggering as shown in FIG. 15 (a). Can be represented.
  • the discovery subframe index K is set to six.
  • the base station beamforming capability has a beam gain of up to 10 dB and a beam width of 120 degrees in 2D (dimension).
  • the discovery subframe index K may be set to 6 subframes. That is, referring to FIG. 15B, subframe indexes 1 and 2 are areas in which beamforming is performed with UE1, and UE1 cannot transmit or receive signals from the base station in the remaining subframes. Therefore, since the timing at which beamforming is matched to UE1 comes after 6 subframes, the discovery subframe index K may be set to 6. This approach can be equally extended even when the beamforming is configured in three dimensions and has a smaller or larger beamwidth.
  • the discovery triggering feedback signal may be transmitted to the base station together with the CSI fed back through the PUSCH or the PUCCH or may be transmitted through the UE grant request message.
  • the mmWave base station determines a subframe in which the discovery signal is transmitted in consideration of the discovery trigger feedback signal and / or channel condition transmitted by the mmWave terminal, and transmits the mmWave discovery signal (S1520).
  • step S1520 if the discovery signal is transmitted in a subframe different from the subframe indicated by the discovery subframe index suggested by the mmWave terminal, the base station may transmit information on the subframe / frame in which the discovery signal is to be transmitted to the mmWave terminal.
  • the mmWave terminal may estimate a subframe / frame to which a discovery signal is to be transmitted based on the discovery subframe index.
  • the mmWave terminal may perform the mmWave discovery process by measuring the mmWave discovery signal in a corresponding subframe according to a predetermined configuration (S1530).
  • FIG. 16 illustrates a process of performing an mmWave cell discovery process according to a determination of an mmWave base station.
  • the mmWave terminal may measure RSRP for mmWave downlink and report it to the base station in a periodic or event triggered manner (S1610).
  • the mmWave base station may determine whether the corresponding link becomes unstable due to LoS / NLoS transition or the like based on the RSRP reported from the mmWave terminal. If the link is unstable, the base station may determine whether to perform the mmWave discovery process and configure the discovery signal to inform the mmWave terminal. That is, when performing the mmWave discovery process, the mmWave base station may transmit a discovery trigger indication signal to the mmWave terminal (S1620).
  • the mmWave discovery trigger indication signal may include a triggering flag indicating whether the mmWave discovery process is performed and a discovery signal index indicating a subframe in which the discovery signal is transmitted.
  • the discovery signal index may be configured to be the same as the discovery subframe index described in Table 7.
  • the mmWave terminal may receive and measure a discovery signal transmitted by the base station in a subframe indicated by the discovery signal index K (S1630 and S1640).
  • Sections 3.1 and 3.2 described above describe a signaling method between an mmWave terminal and an mmWave base station when one or more mmWave cells are disposed.
  • a description will be given of the mmWave cell discovery process according to the request of the mmWave terminal when two or more mmWave cells are configured.
  • FIG. 17 illustrates a method of performing an mmWave cell discovery process in response to a request of an mmWave terminal in a multi-cell arrangement.
  • the mmWave base station configures each mmWave cell.
  • the present invention may be equally applicable to configuring two or more mmWave cells in one mmWave base station, and it may be assumed that different mmWave cells are managed by different mmWave base stations from the viewpoint of mmWave terminals.
  • the two or more mmWave cells may be configured as one mmWave TAG (Traking Area Group), and an Xn interface or overlaying between each mmWave cells.
  • TAG Traffic Area Group
  • Xn overlaying between each mmWave cells.
  • the mmWave terminal is in an RRC connection or mmWave link with mmWave eNB1 and mmWave eNB2, respectively.
  • the mmWave link may refer to a state in which synchronization is performed between the mmWave terminal and the base station as a result of cell search and beamforming performed in Section 2.4.
  • the mmWave link between the mmWave UE and the mmWave eNB1 may become unstable.
  • the cause of the unstable link may refer to the contents described with reference to FIG. 14 (S1710).
  • the mmWave terminal may perform cell boundary discovery through connected up and down links.
  • the discovery trigger feedback may be transmitted to the base station through another mmWave link having good performance, rather than performing a degraded link.
  • the mmWave terminal may transmit a discovery trigger feedback (or discovery trigger request) signal to the mmWave eNB2 having a good link state (S1720).
  • a discovery trigger feedback or discovery trigger request
  • the mmWave terminal should perform the mmWave discovery process again to adjust the mmWave link.
  • the UE may transmit the mmWave discovery trigger signal for mmWave eNB1 through mmWave eNB2 having good link quality.
  • the system configuration of mmWave eNB1 and mmWave eNB2 is preferably set under joint transmission in advance.
  • the discovery trigger feedback signal transmitted in step S1720 may have the same configuration as the discovery trigger feedback signal described in step S1510. However, the discovery trigger feedback signal used in operation S1720 may further include an mmWave base station identifier indicating a base station on which the mmWave discovery process is to be performed.
  • mmWave eNB2 may transmit the discovery trigger feedback signal to the mmWave eNB1 indicated by the mmWave base station identifier through the backhaul (that is, the Xn interface) (S1730).
  • the mmWave eNB1 When mmWave eNB1 receives the discovery trigger feedback signal from mmWave eNB2, it may be confirmed that the link with the mmWave terminal becomes unstable. Accordingly, the mmWave eNB1 may transmit a discovery signal to the UE in a subframe indicated by the discovery subframe index K included in the discovery trigger feedback signal or a subframe set by the base station (S1730).
  • step S1730 if a discovery signal is transmitted in a subframe different from the subframe indicated by the discovery subframe index proposed by the mmWave terminal, the base station transmits information on the subframe / frame in which the discovery signal is to be transmitted to the mmWave terminal via mmWave eNB2. Can be.
  • the mmWave terminal may estimate a subframe / frame to which a discovery signal is to be transmitted based on the discovery subframe index.
  • the mmWave terminal may perform the mmWave discovery process by measuring the mmWave discovery signal in a corresponding subframe according to a predetermined configuration.
  • the mmWave terminal may establish an mmWave link with the mmWave eNB1 by measuring the mmWave discovery signal transmitted by the mmWave eNB1 (S1740).
  • a method of determining whether to perform a mmWave cell discovery process based on information obtained through an RSRP report received from an mmWave terminal by a mmWave base station in a multi-cell environment may be applied to the content described with reference to FIG. 17.
  • FIG. 18 is a diagram illustrating a process of performing an mmWave cell discovery process according to a determination of an mmWave base station in a multi-cell deployment environment.
  • the mmWave terminal may measure RSRP for mmWave downlink and report it to mmWave eNB1 in a periodic or event triggered manner (S1810).
  • the mmWave eNB1 may determine whether the corresponding link is unstable due to LoS / NLoS transition or the like based on the RSRP reported from the mmWave terminal (S1820).
  • mmWave eNB1 may determine whether to perform the mmWave discovery process, configure the discovery signal and inform the mmWave terminal. In this case, the mmWave eNB1 may inform the start of the mmWave discovery process through the mmWave eNB2 having a stable link because the link with the mmWave terminal is unstable. That is, mmWave eNB1 may transmit a discovery trigger indication signal to the mmWave terminal via mmWave eNB2 (S1830, S1840).
  • the mmWave discovery trigger indication signal may include a trigger flag indicating whether the mmWave discovery process is performed, a discovery signal index indicating a subframe in which the discovery signal is transmitted, and base station identifier information indicating a base station to perform the mmWave discovery process.
  • the discovery signal index may be configured to be the same as the discovery subframe index described in Table 7.
  • the mmWave terminal may receive and measure a discovery signal from mmWave eNB1 indicated by the base station identifier information in a subframe indicated by the discovery signal index K (S1850 and S1860).
  • mmWave discovery trigger feedback signal ie, mmWave discovery request signal
  • FIG. 19 illustrates one method of transmitting an mmWave discovery trigger feedback signal.
  • the mmWave terminal may transmit the RSRP value to the mmWave BS1 together with or separately from the CRS or CSI-RS at a timing of transmitting the CRS or CSI-RS through the mmWave uplink.
  • the mmWave downlink can be transmitted to another mmWave terminal connected to another mmWave link according to the mmWave beam performance.
  • the description thereof may refer to FIG. 13.
  • the mmWave BS1 may transmit the mmWawe discovery trigger indication signal in the beamforming direction in which the mmWave terminal and the mmWave link were established again.
  • the mmWave discovery trigger indication signal may be transmitted to the terminal at the ACK / NACK transmission timing corresponding to the uplink data.
  • FIG. 20 is a diagram for describing a method of transmitting a discovery trigger indication signal at a transmission timing of all mmWave cells according to UE performance for all mmWave cells configured together in one mmWave base station.
  • the mmWave terminal may not be able to receive a discovery trigger indication signal from mmWave BS1. That is, since the RSRP value decreases due to link degradation, it may not be desirable to transmit the mmWave trigger indication signal to the mmWave terminal through the corresponding link. Accordingly, the mmWave BS1 may transmit the discovery trigger indication signal through all mmWave cells configured in the mmWave BS1 as well as transmitting the mmWave discovery trigger indication signal only through the existing mmWave cell as shown in FIG. 19.
  • mmWave BS1 may transmit a discovery trigger indication signal in subframes corresponding to all mmWave cells.
  • the transmission overhead of the base station is increased, the diversity for the discovery trigger indication signal is increased.
  • FIG. 21 is a diagram for describing a method of periodically transmitting a discovery trigger feedback signal according to an uplink transmission timing period set according to mmWave system information.
  • the mmWave base station illustrated in FIG. 21 may preset and allocate an uplink resource for transmitting a discovery trigger feedback indication signal.
  • the uplink resource may be allocated separately for each specific mmWave terminal or may be allocated in common.
  • the mmWave BS1 may periodically receive channel quality information such as RSRP from all mmWave terminals having a link established with the mmWave BS1 through periodically allocated uplink resources.
  • the base station transmits CRS and / or CSI-RS to one or more mmWave terminals.
  • One or more mmWave terminals may measure RSRP using CRS and / or CSI-RS. Thereafter, mmWave terminals may transmit a discovery trigger feedback signal through the allocated mmWave uplink resource.
  • the discovery trigger feedback signal includes the terminal identifier of each mmWave terminal to explicitly identify the corresponding terminal, or the mmWave terminal may be implicitly distinguished through an uplink through which the discovery trigger feedback signal is transmitted.
  • the mmWave base station may determine whether to perform mmWave discovery for each terminal based on the received mmWave discovery feedback signal. Thereafter, the mmWave base station may indicate whether the mmWave discovery process is performed for each specific mmWave terminal. Thereafter, the mmWave base station may transmit a dedicated RS or a demodulation RS (DRS) for each terminal as a discovery signal.
  • DRS demodulation RS
  • the base station collects information on a plurality of terminals at the same time and may determine whether to perform the mmWave discovery process.
  • Section 3.5 may be applied to Sections 3.1 and 3.2 as it is, and may also be applied to Sections 3.3 and 3.4, which correspond to the case where a plurality of mmWave cells are configured.
  • the apparatus described in FIG. 22 is a means in which the methods described in FIGS. 1 to 21 can be implemented.
  • a user equipment may operate as a transmitter in uplink and a receiver in downlink.
  • an e-Node B eNB
  • eNB e-Node B
  • the terminal and the base station may include transmitters 2240 and 2250 and receivers 2250 and 2270 to control the transmission and reception of information, data and / or messages, respectively.
  • antennas 2200 and 2210 for transmitting and receiving messages.
  • the terminal and the base station may each include a processor 2220 and 2230 for performing the above-described embodiments of the present invention, and memories 2280 and 2290 capable of temporarily or continuously storing 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.
  • the terminal is an mmWave terminal, and the processor of the terminal may perform mmWave beamforming (eg, analog, hybrid beamforming, etc.) by controlling the transmitter and the receiver.
  • the mmWave terminal may measure the downlink data channel to configure link identification information and feed back to the mmWave base station.
  • the mmWave base station may allocate resources for the mmWave terminal based on the received feedback information.
  • the processor of the mmWave terminal may transmit the configured discovery trigger feedback signal to the mmWave base station by controlling the transmitter.
  • the processor of the mmWave terminal may control the receiver to receive the mmWave discovery trigger indication signal and / or discovery signal transmitted from the mmWave base station.
  • the processor of the mmWave base station may control the receiver to receive a discovery trigger feedback signal transmitted from the mmWave terminal or another mmWave base station, and may determine whether to perform the mmWave discovery process based on this.
  • the processor of the mmWave base station may control the transmitter to transmit the discovery trigger indication signal and / or the discovery signal to the mmWave terminal.
  • 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. 22 may further include a low power radio frequency (RF) / intermediate frequency (IF) module.
  • 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 2280 and 2290 and driven by the processors 2220 and 2230.
  • 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.

Abstract

La présente invention concerne un système d'accès sans fil prenant en charge une onde millimétrique (mmWave) et, en particulier, des procédés de signalisation pour exécuter un processus de découverte exécuté dans une cellule mmWave et des appareils prenant en charge ce procédé. Dans un mode de réalisation de la présente invention, un procédé de prise en charge d'un processus de découverte d'onde millimétrique dans un système d'accès sans fil prenant en charge des ondes millimétriques (mmWave) peut comprendre : si la qualité d'une liaison mmWave est dégradée, la transmission, par un terminal mmWave, d'un signal de rétroaction de déclenchement de découverte demandant l'initiation du processus de découverte de mmWave; et la réception, par le terminal mmWave, d'un signal de découverte mmWave dans une sous-trame indiquée par un indice de sous-trame de découverte. Le signal de rétroaction de déclenchement de découverte peut contenir un indice de sous-trame de découverte indiquant une sous-trame dans laquelle le signal de découverte mmWave doit être transmis.
PCT/KR2016/005149 2016-05-16 2016-05-16 Procédé et appareil de signalisation pour exécuter un processus de découverte dans un système d'accès sans fil prenant en charge des ondes millimétriques WO2017200112A1 (fr)

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US20140242963A1 (en) * 2013-02-22 2014-08-28 Samsung Electronics Co., Ltd. Network-assisted multi-cell device discovery protocol for device-to-device communications
WO2015065112A1 (fr) * 2013-10-31 2015-05-07 엘지전자(주) Procédé de transmission d'un message de découverte dans un système de communication sans fil, et appareil correspondant
US20150223088A1 (en) * 2014-01-31 2015-08-06 Intel Corporation Techniques for mmwave-capable small cell detection
US20150326359A1 (en) * 2014-05-08 2015-11-12 Qualcomm Incorporated Cooperative techniques between lower-frequency carriers and millimeter-wave channels for discovery and synchronization and beamforming

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Publication number Priority date Publication date Assignee Title
US20140242963A1 (en) * 2013-02-22 2014-08-28 Samsung Electronics Co., Ltd. Network-assisted multi-cell device discovery protocol for device-to-device communications
WO2015065112A1 (fr) * 2013-10-31 2015-05-07 엘지전자(주) Procédé de transmission d'un message de découverte dans un système de communication sans fil, et appareil correspondant
US20150223088A1 (en) * 2014-01-31 2015-08-06 Intel Corporation Techniques for mmwave-capable small cell detection
US20150326359A1 (en) * 2014-05-08 2015-11-12 Qualcomm Incorporated Cooperative techniques between lower-frequency carriers and millimeter-wave channels for discovery and synchronization and beamforming

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