WO2017188471A1 - Resource allocation method and device in wireless access system supporting millimeter wave - Google Patents

Resource allocation method and device in wireless access system supporting millimeter wave Download PDF

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Publication number
WO2017188471A1
WO2017188471A1 PCT/KR2016/004415 KR2016004415W WO2017188471A1 WO 2017188471 A1 WO2017188471 A1 WO 2017188471A1 KR 2016004415 W KR2016004415 W KR 2016004415W WO 2017188471 A1 WO2017188471 A1 WO 2017188471A1
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mmwave
resource allocation
cell
allocation configuration
tag
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PCT/KR2016/004415
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French (fr)
Korean (ko)
Inventor
최국헌
고현수
노광석
김동규
이상림
이호재
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엘지전자 주식회사
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Priority to PCT/KR2016/004415 priority Critical patent/WO2017188471A1/en
Publication of WO2017188471A1 publication Critical patent/WO2017188471A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/16—Time-division multiplex systems in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/08—Testing, supervising or monitoring using real traffic
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/04—Wireless resource allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria

Definitions

  • the present invention relates to a wireless access system that supports millimeter wave (mmWave), and relates to mmWave multi-link band-based resource allocation methods, data transmission methods and apparatuses for supporting the same in the mmWave cell.
  • 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 resource allocation method for preventing redundant allocation of resources in a multi-link cell environment configured in an mmWave system.
  • Another object of the present invention is to provide a resource allocation method for reducing inter-cell interference in a multi-link cell environment configured 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 that supports millimeter wave (mmWave), and provides mmWave multi-link band-based resource allocation methods, data transmission methods, and apparatuses for supporting the same in a mmWave cell.
  • mmWave millimeter wave
  • the present invention relates to a wireless access system that supports millimeter wave (mmWave), and provides mmWave multi-link band-based resource allocation methods, data transmission methods, and apparatuses for supporting the same in a mmWave cell.
  • a method for allocating resources by a mmWave base station in a wireless access system supporting millimeter wave may be provided in all mmWave cells configured in a tracking area group (TAG) including two or more mmWave base stations.
  • TAG tracking area group
  • the method includes measuring the inter-mmWave inter-cell interference in the TAG based on the resource allocation configuration information, and when the inter-mmWave inter-cell interference occurs, the resource allocation configuration information modified in consideration of the multi-mmWave inter-cell interference, and all the mmWave base stations in the TAG
  • the method may further include transmitting to.
  • an apparatus for allocating resources in a radio access system supporting millimeter wave may include a transmitter, a receiver, and a processor.
  • the processor controls the transmitter and the receiver to measure the distribution for the mmWave terminals present in all mmWave cells configured in a TAG (Tracking Area Group) containing two or more mmWave base stations; Generate resource allocation configuration information for multiple mmWave links based on the measured distribution of mmWave terminals;
  • the transmitter may be configured to control the transmitter to transmit an allocation configuration message including resource allocation configuration information to all mmWave base stations included in the TAG.
  • the processor controls a receiver to measure the interference between multiple mmWave cells in a TAG based on resource allocation configuration information; If multiple mmWave inter-cell interference occurs, the modified resource allocation configuration information may be further controlled to transmit to all mmWave base stations in the TAG in consideration of the multiple mmWave inter-cell interference.
  • the resource allocation configuration message may include identifiers of the mmWave base stations belonging to the TAG and resource allocation configuration information indicating the resources allocated to the mmWave cells configured in each mmWave base stations.
  • the mmWave base stations included in the TAG may have two or more mmWave cells according to their respective capabilities, and two or more mmWave cells may be allocated different radio resources in a time division multiplex (TDM) manner.
  • TDM time division multiplex
  • the modified resource allocation configuration information may include the identifier of the mmWave base station whose resource allocation configuration information has been changed, the changed mmWave cell index, and the modified mmWave cell holding time information.
  • radio frequency allocation is taken into account in consideration of the distribution of mmWave terminals in mmWave cells to reduce intra-cell interference in mmWave cell setup. Can be.
  • 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 view for explaining the mmWave small cell structure.
  • FIG. 11 is a diagram for explaining an mmWave cell structure in analog beamforming.
  • FIG. 12 is a view for explaining the distribution and configuration of mmWave cell in each cell of mmWave terminals in one mmWave base station.
  • FIG. 13 is a diagram for describing a multi link cell and beam timing configured in mmWave base stations.
  • FIG. 14 is a diagram for describing multiple mmWave links that can be set in an mmWave terminal.
  • FIG. 15 is a diagram for explaining ambiguity of multi-link configuration when there is an mmWave terminal that desires another link connection pattern.
  • FIG. 16 is a diagram illustrating a method of configuring multiple mmWave cells for multiple link connection to an mmWave base station.
  • FIG. 17 illustrates one method of allocating mmWave multi-cell resources.
  • FIG. 18 is a diagram illustrating a resource allocation method for reducing link instability in a multi-mmWave link environment.
  • 19 is another diagram for explaining a resource allocation method for reducing link instability in a multi-mmWave link environment.
  • FIG. 20 is a means by which the methods described in FIGS. 1 to 19 may 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 specific frequency and the simplest signal quality (eg RSSI) measurement. 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.
  • FIG. 10 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. 11 is a diagram for explaining an mmWave cell structure in analog beamforming.
  • FIG. 11 (a) shows the appearance of an omni mmWave cell
  • FIG. 11 (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. 12 is a view for explaining the distribution and configuration of mmWave cell 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. 12 (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.
  • 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 performed separately 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.
  • mmWave cells configured based on the supportable beamwidth of the corresponding base station in one base station may be configured as one tracking area group (TAG).
  • TAG tracking area group
  • mmWave cells that perform cooperative operation to transmit data to a specific mmWave terminal may be configured as one TAG.
  • mmWave cells may belong to different mmWave base stations.
  • mmWave base stations e.g., mmWave TAG
  • inter-cell interference between cells located in an inter site can be reduced through spatial multiplexing. This may provide an opportunity to increase the transmission rate required by the mmWave terminal.
  • the mmWave system may perform multi-link transmission.
  • the dense mmWave base stations for such a terminal may have different transmission directions (ie, beamforming directions) so that cell areas do not overlap at one timing. In this way, the inter-cell interference can be reduced by avoiding the mmWave cells configured in each base station and by transmitting the transmission time timing to each divided spatial cell.
  • the mmWave base station may allocate radio resources in a manner that avoids transmission or reduces the transmission amount to the unstable mmWave link.
  • each mmWave base station can form a different cell direction at the same timing to maintain SINR.
  • the mmWave base station can transmit data at a constant MCS level and can easily synchronize time and / or frequency synchronization for each link.
  • FIG. 13 is a diagram for describing a multi link cell and beam timing configured in mmWave base stations.
  • mmWave link between base station and UE is unstable due to its characteristics.
  • mmWave users assume that they have mmWave multilink connection capability (ie, having multiple mmWave RF chains) to overcome link instability.
  • FIG. 13 illustrates an example of reducing interference between mmWave cells by setting a cell configuration between each intersite in a TDM scheme.
  • each mmWave base station forms an mmWave cell with a beam width of 45 degrees. That is, eight mmWave cells may be configured in one mmWave base station. As such, mmWave base stations configured with mmWave cells may be configured with one TAG.
  • radio resources may be allocated to each mmWave cell in a TDM manner.
  • one transmission time interval (TTI) of the mmWave system may be set to 1 ms, 0.5 ms or less, but is assumed to be 1 ms for convenience. In other words, it is assumed that one subframe is one TTI.
  • the number in each subframe of FIG. 13 (b) means the index and subframe index of mmWave cells configured in each base station of FIG. 13 (a).
  • mmWave cell 2 of mmWave BS0 is in subframe index 2
  • mmWave cell 6 of mmWave BS1 is in subframe index 6
  • mmWave cell 0 in mmWave BS2 is subframe index 0
  • the mmWave terminal may increase the data throughput in the case of multiple mmWave links (for example, by transmitting and receiving data with three mmWave base stations) than in the case of a single mmWave link.
  • the shape and subframe configuration of the mmWave cells shown in FIG. 13 is one example, and the number of mmWave cells and the like may vary depending on the performance (eg, supportable beamwidth, etc.) of the mmWave base station.
  • the mmWave terminal performs analog beamforming and hybrid beamforming processes as described in mmWave BS0 to BS2 and FIGS. 8 to 9.
  • FIG. 14 is a diagram for describing multiple mmWave links that can be set in an mmWave terminal.
  • the symbol duration may be considerably shorter in the mmWave band of 6 GHz or more.
  • the symbol used in the mmWave system is about 1/8 of the OFDM symbol in the existing LTE / LTE-A system (ie, about 10us (1.7us (cp) + 8.3us)
  • the cyclic prefix (CP: Cyclic Prefix) Length can also be shortened. Therefore, even in a situation where the time synchronization between the adjacent transmission points is strictly matched, the signal delay that occurs according to the distance between the transmission point and the receiving point has various values from multiple transmission points and comes from many transmission points. It becomes difficult to guarantee that the signal is within the CP range.
  • each mmWave base station In order for several base stations to perform joint transmission for a certain mmWave user, each mmWave base station must direct an analog beam for a specific terminal at a specific timing. However, if multiple users are in the cell or there are mmWave users with different transmission and reception patterns, multiple access between multiple users should be considered. Thus, the method of adjusting each cell allocation time can be quite complex.
  • FIG. 15 is a diagram for explaining ambiguity of multi-link configuration when there is an mmWave terminal that desires another link connection pattern.
  • mmWave UE0 and mmWave UE1 are located in the mmWave cell region of mmWave BS0 and mmWave BS1. It is assumed that mmWave UE0 is a terminal that wants to simultaneously connect to mmWave BS0 and BS1, and mmWave UE1 is a terminal that wants to connect only to mmWave BS0. At this time, mmWave UE0 has no problem because it wants to simultaneously connect with mmWave BS0 and BS1, but mmWave UE1 may receive interference from mmWave BS1 because it wants to connect only to mmWave BS0. In addition, ambiguity may occur whether mmWave BS1 should transmit data for mmWave UE0 or not because it interferes with mmWave UE1.
  • each mmWave base stations may configure resources for multiple access of mmWave terminals. That is, by allocating resources to the mmWave terminal with a predetermined transmission pattern between the mmWave cells colocated in the mmWave base stations (see FIG. 13), not only the link stability may be improved but also the user transmission rate may be increased.
  • multiple cells may be used to minimize transmission interference between mmWave cells.
  • an mmWave terminal having a multi-link connection capability may include identifiers of mmWave cells co-located with each mmWave base station having a link connection and TA values for each mmWave cells. It is assumed that the frequency offset value is known in advance. In addition, it is assumed that the mmWave terminal is synchronized with each mmWave base station.
  • FIG. 16 is a diagram illustrating a method of configuring multiple mmWave cells for multiple link connection to an mmWave base station.
  • FIG. 16 The basic setting of FIG. 16 is the same as that of FIG. However, only the deployment form of mmWave base stations is different.
  • mmWave cell 6 of mmWave BS0 is in subframe index 6
  • mmWave cell 2 of mmWave BS1 is in subframe index 2
  • mmWave cell 0 in mmWave BS2 is mmWave terminal in subframe index 0, respectively.
  • Radio resources can be allocated to transmit and receive data.
  • mmWave BS2 may allocate more radio resources for mmWave cell 0 than other mmWave cells 1-7.
  • time intervals of radio resources allocated to mmWave cell 2 in mmWave BS1 and radio resources allocated to mmWave cell 0 in mmWave BS2 may overlap. In this case, interference between mmWave cells may occur in the mmWave terminal.
  • mmWave BS1 can avoid interference by changing the position of subframe 2, which is a radio resource allocated to mmWave cell 2, to subframe 4 as shown in FIG. 16 (c). That is, mmWave BS1 can set a resource configuration that avoids intra-cell interference by modifying mmWave cell timing.
  • each mmWave base station should measure the number or density of mmWave terminals distributed in its mmWave cells in real time, and the number of mmWave terminals distributed in mmWave cells of another mmWave base station. Or it is desirable to know the density. Through this, each mmWave base stations can configure resources for mmWave cells.
  • FIG. 17 illustrates one method of allocating mmWave multi-cell resources.
  • FIG. 17 is performed based on the cell configuration described in FIG. 16 and relates to a method of configuring radio resources for mmWave cells in mmWave BS1. It is assumed that mmWave BS1 or mmWave BS0 to BS2 constitute one TAG.
  • the mmWave master BS which manages the mmWave MME or mmWave TAG, an entity that manages the mobility of mmWave terminals in the mmWave system, measures the number or density of mmWave terminals distributed in all mmWave cells in the TAG in real time, periodically, or on demand. do. Thereafter, the mmWave MME or mmWave master BS may perform resource allocation configuration for each mmWave cell.
  • the mmWave master BS may be set to any mmWave BS in the TAG or may be a higher entity for managing a TAG provided on the mmWave system (S1710).
  • mmWave MME or mmWave master BS may transmit the resource allocation configuration information to all mmWave BSs in the TAG over the backhaul network.
  • the resource allocation configuration information may include information about the resource allocation configuration in the form shown in FIG. 13 (b) or 16 (b).
  • the mmWave MME or mmWave master BS can identify the interference between multiple cells based on the resource allocation configuration information.
  • Inter-cell interference may be interference between mmWave cells or interference for a particular mmWave terminal.
  • the distribution of mmWave terminals in the mmWave cell may be changed due to the movement of mmWave terminals. For this reason, the resource configuration allocated to the mmWave cell by the mmWave base station may be changed (S1720).
  • step S1720 if the overlapping cell does not occur based on the resource allocation configuration information, the mmWave MME or mmWave master BS transmits a resource allocation configuration message including resource allocation configuration information for multiple cells to mmWave BSs in each mmWave TAG. (S1740).
  • step S1720 when a cell overlapping in the time domain between mmWave cells occurs based on resource allocation configuration information, mmWave MME or mmWave master BS modifies resource allocation configuration information for multiple cells in consideration of interference in the cell (S1730). ).
  • the mmWave MME or mmWave master BS transmits a resource allocation configuration message including the modified resource allocation configuration information to the mmWave BSs in each mmWave TAG (S1740).
  • the resource allocation configuration message may include an identifier of each mmWave BSs and resource allocation information for mmWave cells configured in each mmWave BSs. If the resource allocation configuration is changed due to a change in the distribution of mmWave terminals in the TAG or a resource allocation for the mmWave cell, the identifier information of the mmWave base station with the changed mmWave cell transmission order (for example, in mmWave BS1). Identifiers), modified mmWave cell indexes (eg, mmWave cell indexes 2 and 4) and modified mmWave cell retention time information.
  • modified mmWave cell indexes eg, mmWave cell indexes 2 and 4
  • FIG. 18 is a diagram illustrating a resource allocation method for reducing link instability in a multi-mmWave link environment.
  • each mmWave BS is connected to each other through an Xn interface as a backhaul network, and that an MME is connected to each mmWave BS with a backhaul network.
  • the resource allocation configuration of FIG. 18 is basically configured as shown in FIG. 16B in the same manner as in FIG. 17.
  • FIG. 18A illustrates a state in which multiple mmWave cells are set and target link stability is deteriorated according to mmWave user distribution in the mmWave cell.
  • a large number of mmWave users are distributed in mmWave cell 0 of mmWave BS2.
  • the mmWave link of the target mmWave terminal transitions from LoS to NLoS can greatly increase the link instability.
  • mmWave cell 2 of mmWave BS1 and mmWave cell 0 of mmWave BS2 transmit signals at the same time, inter-cell interference may occur in the target mmWave terminal.
  • the mmWave BS2 may transmit a Sequence Number (SN) status transfer message to the MME and mmWave BS1 through the backhaul network.
  • SN Sequence Number
  • the SN status transfer message is transmitted to inform the number of packets not transmitted or the number of packets to be transmitted and received in mmWave BS2.
  • the MME can avoid intra-cell interference resulting from mmWave BS2 by changing the positions of cell indexes 2 and 4 of mmWave BS1.
  • the mmWave BS1 may receive an SN status transfer message from the mmWave BS2, so that the next packet to be transmitted to the target mmWave terminal may be known. Accordingly, mmWave BS1 may continue to transmit data packets on mmWave cell 2 and subframe 2 indicated by modified cell index 2.
  • FIG. 18C the mmWave BS1 may receive an SN status transfer message from the mmWave BS2, so that the next packet to be transmitted to the target mmWave terminal may be known. Accordingly, mmWave BS1 may continue to transmit data packets on mmWave cell 2 and subframe 2 indicated by modified cell index 2.
  • the target mmWave terminal may have multiple mmWave link connection capability.
  • the target mmWave terminal is unstable as the target mmWave link connected to the mmWave cell as shown in Figure 18 (a)
  • mmWave BS2 transmits an SN status transfer message to the next mmWave BS (for example, mmWave BS1) or MME Next, transmit the data packet indicated by the SN status transfer message on the next mmWave link.
  • the SN status transfer message may include a temporary UE ID indicating a target mmWave terminal to which data is to be transmitted.
  • 19 is another diagram for explaining a resource allocation method for reducing link instability in a multi-mmWave link environment.
  • FIG. 19 describes the contents described with reference to FIG. 18 in terms of MME and mmWave master BS.
  • the mmWave master BS which manages the mmWave MME or mmWave TAG, an entity that manages the mobility of mmWave terminals in the mmWave system, measures the number or density of mmWave terminals distributed in all mmWave cells in the TAG in real time, periodically, or on demand. do. Thereafter, the mmWave MME or mmWave master BS may perform resource allocation configuration for each mmWave cell.
  • the mmWave master BS may be set to any mmWave BS in the TAG or may be a higher entity for managing the TAG provided on the mmWave system (S1910).
  • mmWave MME or mmWave master BS may transmit the resource allocation configuration information to all mmWave BSs in the TAG over the backhaul network.
  • the resource allocation configuration information may include information on the resource allocation configuration in the form of FIG. 13 (b), FIG. 16 (b), or FIG. 18 (a).
  • the mmWave base stations included in the mmWave TAG each measure the link stability of the mmWave cells configured together. For example, in FIG. 18 (b), mmWave BS2 measures link stability for mmWave cell 0 to confirm that LoS / NLoS transition has occurred (S1920).
  • the mmWave base station managing the mmWave link may transmit the SN transfer message to other mmWave BSs of the MME or TAG.
  • mmWave BS2 may transmit an SN status transfer message indicating an SN for a data packet not transmitted by mmWave cell 0 to MME or other mmWave BSs (S1930).
  • step S1930 when the MME receives the SN status forwarding message, the SN status forwarding message is transmitted to the base station of the mmWave cell to which the mmWave link is connected or all the mmWave base stations in the TAG at the earliest time based on the resource allocation configuration information.
  • the MME may send an SN status transfer message to mmWave BS1.
  • data may be subsequently transmitted at a time point when the target mmWave terminal and the mmWave link are connected in the mmWave BS1 (that is, the changed subframe 2) (S1940).
  • mmWave BS2 may transmit the SN status transmission message to all mmWave base stations belonging to the TAG.
  • the mmWave base stations receiving the SN status transfer message may transmit a data packet indicated by the SN to the target mmWave terminal in step S1940.
  • embodiments of the present invention can be applied even when mmWave cells collocated with mmWave base stations in the mmWave TAG are arranged at a dense density. At this time, embodiments of the present invention can reduce the intra-cell interference when configuring the mmWave cell by allocating radio resources in consideration of the distribution of mmWave terminals in the mmWave cells. In addition, considering the instability of the mmWave link, it is possible to allocate multiple link resources.
  • inter-cell interference can be reduced even in a multi-mmWave link environment, and time / frequency synchronization can be easily adjusted. This is because the mmWave terminal and the mmWave base stations already know the TA and frequency offset for the specific cell connection at a specific timing.
  • a transmission rate for each mmWave terminal may be improved. For example, in the case of a single mmWave link environment, data may be transmitted and received only once in eight transmission opportunities. However, in the case of FIG. 16 (c), data is transmitted and received three times during eight transmission opportunities. This can be improved by three times.
  • FIG. 20 is a means by which the methods described in FIGS. 1 to 19 may 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 2040 and 2050 and receivers 2050 and 2070 to control the transmission and reception of information, data and / or messages, respectively.
  • antennas 2000 and 2010 for transmitting and receiving messages.
  • the terminal and the base station may each include a processor 2020 and 2030 for performing the above-described embodiments of the present invention and a memory 2080 and 2090 for 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 and transmit the resource allocation information to the mmWave terminal and / or another mmWave base station. For details, refer to the contents described in Sections 1 to 3.
  • 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. 20 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 2080 and 2090 and driven by the processors 2020 and 2030.
  • 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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Abstract

The present invention relates to a wireless access system supporting millimeter wave (mmWave), and provides resource allocation methods on the basis of a mmWave multi-link band in a mmWave cell and devices for supporting the same. According to an embodiment of the present invention, a method for allocating a resource by a millimeter wave (mmWave) base station in a wireless access system supporting mmWave may comprise the steps of: measuring a distribution of mmWave terminals existing within all mmWave cells included in a tracking area group (TAG) including two or more mmWave base stations; generating resource allocation configuration information for multiple mmWave links on the basis of the measured distribution of the mmWave terminals; and transmitting an allocation configuration message including the resource allocation configuration information to all mmWave base stations included in the TAG.

Description

[규칙 제26조에 의한 보정 30.05.2016]　밀리미터웨이브를 지원하는 무선접속 시스템에서 자원할당방법 및 장치[Correction 30.05.2016 by Rule 26] 및 Resource Allocation Method and Apparatus in a Wireless Access System Supporting Millimeter Wave
본 발명은 밀리미터웨이브(mmWave)를 지원하는 무선 접속 시스템에 관한 것으로, mmWave 셀에서 mmWave 멀티 링크 밴드 기반의 자원 할당 방법들, 데이터 전송 방법들 및 이를 지원하기 위한 장치들에 관한 것이다.The present invention relates to a wireless access system that supports millimeter wave (mmWave), and relates to mmWave multi-link band-based resource allocation methods, data transmission methods and apparatuses for supporting the same in the mmWave cell.
무선 접속 시스템이 음성이나 데이터 등과 같은 다양한 종류의 통신 서비스를 제공하기 위해 광범위하게 전개되고 있다. 일반적으로 무선 접속 시스템은 가용한 시스템 자원(대역폭, 전송 파워 등)을 공유하여 다중 사용자와의 통신을 지원할 수 있는 다중 접속(multiple access) 시스템이다. 다중 접속 시스템의 예들로는 CDMA(code division multiple access) 시스템, FDMA(frequency division multiple access) 시스템, TDMA(time division multiple access) 시스템, OFDMA(orthogonal frequency division multiple access) 시스템, SC-FDMA(single carrier frequency division multiple access) 시스템 등이 있다.Wireless access systems are widely deployed to provide various kinds of communication services such as voice and data. In general, 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.). Examples of 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.
본 발명의 목적은 mmWave 시스템에서 효율적인 데이터 통신을 지원하는 것이다.An object of the present invention is to support efficient data communication in the mmWave system.
본 발명의 다른 목적은 mmWave 시스템에서 구성되는 다중 링크 셀 환경에서 자원의 중복 할당을 방지하기 위한 자원할당 방법을 제공하는 것이다.Another object of the present invention is to provide a resource allocation method for preventing redundant allocation of resources in a multi-link cell environment configured in an mmWave system.
본 발명의 또 다른 목적은 mmWave 시스템에서 구성되는 다중 링크 셀 환경에서 셀 간 간섭을 줄이기 위한 자원할당 방법을 제공하는 것이다.Another object of the present invention is to provide a resource allocation method for reducing inter-cell interference in a multi-link cell environment configured in an mmWave system.
본 발명의 또 다른 목적은 mmWave 시스템에서 구성되는 다중 링크 셀 환경에서 LoS/NLoS 천이시 발생하는 링크 단절시 데이터를 끊임없이 단말에 제공하는 방법을 제공하는 것이다.It is still another object of the present invention to provide a method for continuously providing data to a terminal during link disconnection that occurs during LoS / NLoS transition in a multi-link cell environment configured in an mmWave system.
본 발명의 또 다른 목적은 이러한 방법들을 지원하는 장치에 관한 것이다.Yet another object of the present invention is to provide an apparatus for supporting such methods.
본 발명에서 이루고자 하는 기술적 목적들은 이상에서 언급한 사항들로 제한되지 않으며, 언급하지 않은 또 다른 기술적 과제들은 이하 설명할 본 발명의 실시예들로부터 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에 의해 고려될 수 있다.Technical objects to be achieved in the present invention are not limited to the above-mentioned matters, and other technical problems which are not mentioned are those skilled in the art from the embodiments of the present invention to be described below. Can be considered.
본 발명은 밀리미터웨이브(mmWave)를 지원하는 무선 접속 시스템에 관한 것으로, mmWave 셀에서 mmWave 멀티 링크 밴드 기반의 자원 할당 방법들, 데이터 전송 방법들 및 이를 지원하기 위한 장치들을 제공한다.The present invention relates to a wireless access system that supports millimeter wave (mmWave), and provides mmWave multi-link band-based resource allocation methods, data transmission methods, and apparatuses for supporting the same in a mmWave cell.
본 발명의 일 양태로서 밀리미터웨이브(mmWave)를 지원하는 무선접속 시스템에서 mmWave 기지국이 자원을 할당하는 방법은, 둘 이상의 mmWave 기지국이 포함된 TAG(Tracking Area Group) 내에 구성되는 모든 mmWave 셀들 내에 존재하는 mmWave 단말들에 대한 분포를 측정하는 단계와 측정한 mmWave 단말들에 대한 분포를 기반으로 다중 mmWave 링크에 대한 자원 할당 구성 정보를 생성하는 단계와 자원 할당 구성 정보를 포함하는 할당 구성 메시지를 TAG 내에 포함된 모든 mmWave 기지국들에 전송하는 단계를 포함할 수 있다.In one aspect of the present invention, a method for allocating resources by a mmWave base station in a wireless access system supporting millimeter wave (mmWave) may be provided in all mmWave cells configured in a tracking area group (TAG) including two or more mmWave base stations. Measuring the distribution for the mmWave terminals, generating resource allocation configuration information for the multiple mmWave links based on the measured distribution for the mmWave terminals and includes an allocation configuration message including the resource allocation configuration information in the TAG And transmitting to all of the mmWave base stations.
상기 방법은, 자원 할당 구성 정보를 기반으로 TAG 내의 다중 mmWave 셀간 간섭을 측정하는 단계와 다중 mmWave 셀간 간섭이 발생하면, 다중 mmWave 셀간 간섭을 고려하여 수정된 자원 할당 구성 정보를 TAG 내의 모든 mmWave 기지국들로 전송하는 단계를 더 포함할 수 있다.The method includes measuring the inter-mmWave inter-cell interference in the TAG based on the resource allocation configuration information, and when the inter-mmWave inter-cell interference occurs, the resource allocation configuration information modified in consideration of the multi-mmWave inter-cell interference, and all the mmWave base stations in the TAG The method may further include transmitting to.
본 발명의 다른 양태로서 밀리미터웨이브(mmWave)를 지원하는 무선접속 시스템에서 자원을 할당하는 장치는 송신기, 수신기 및 프로세서를 포함할 수 있다. 이때, 프로세서는 송신기 및 수신기를 제어하여 둘 이상의 mmWave 기지국이 포함된 TAG(Tracking Area Group) 내에 구성되는 모든 mmWave 셀들 내에 존재하는 mmWave 단말들에 대한 분포를 측정하고; 측정한 mmWave 단말들에 대한 분포를 기반으로 다중 mmWave 링크에 대한 자원 할당 구성 정보를 생성하고; 송신기를 제어하여 자원 할당 구성 정보를 포함하는 할당 구성 메시지를 TAG 내에 포함된 모든 mmWave 기지국들에 전송하도록 구성될 수 있다.In another aspect of the present invention, an apparatus for allocating resources in a radio access system supporting millimeter wave (mmWave) may include a transmitter, a receiver, and a processor. At this time, the processor controls the transmitter and the receiver to measure the distribution for the mmWave terminals present in all mmWave cells configured in a TAG (Tracking Area Group) containing two or more mmWave base stations; Generate resource allocation configuration information for multiple mmWave links based on the measured distribution of mmWave terminals; The transmitter may be configured to control the transmitter to transmit an allocation configuration message including resource allocation configuration information to all mmWave base stations included in the TAG.
상기 프로세서는 자원 할당 구성 정보를 기반으로 TAG 내의 다중 mmWave 셀간 간섭을 수신기를 제어하여 측정하고; 다중 mmWave 셀간 간섭이 발생하면, 다중 mmWave 셀간 간섭을 고려하여 수정된 자원 할당 구성 정보를 송신기를 제어하여 TAG 내의 모든 mmWave 기지국들로 전송하도록 더 구성될 수 있다.The processor controls a receiver to measure the interference between multiple mmWave cells in a TAG based on resource allocation configuration information; If multiple mmWave inter-cell interference occurs, the modified resource allocation configuration information may be further controlled to transmit to all mmWave base stations in the TAG in consideration of the multiple mmWave inter-cell interference.
이때, 자원 할당 구성 메시지에는 TAG 내에 속한 mmWave 기지국들의 식별자 및 각 mmWave 기지국들에 구성된 mmWave 셀들에 할당된 자원을 나타내는 자원 할당 구성 정보가 포함될 수 있다.In this case, the resource allocation configuration message may include identifiers of the mmWave base stations belonging to the TAG and resource allocation configuration information indicating the resources allocated to the mmWave cells configured in each mmWave base stations.
TAG 내에 포함된 mmWave 기지국들은 각각의 성능에 따라 둘 이상의 mmWave 셀을 가질 수 있고, 둘 이상의 mmWave 셀들은 서로 다른 무선 자원을 시간분할다중(TDM) 방식으로 할당받을 수 있다.The mmWave base stations included in the TAG may have two or more mmWave cells according to their respective capabilities, and two or more mmWave cells may be allocated different radio resources in a time division multiplex (TDM) manner.
수정된 자원 할당 구성 정보는 자원 할당 구성 정보가 변경된 mmWave 기지국의 식별자, 변경된 mmWave 셀 인덱스 및 수정된 mmWave 셀 유지 시간 정보가 포함될 수 있다.The modified resource allocation configuration information may include the identifier of the mmWave base station whose resource allocation configuration information has been changed, the changed mmWave cell index, and the modified mmWave cell holding time information.
상술한 본 발명의 양태들은 본 발명의 바람직한 실시예들 중 일부에 불과하며, 본원 발명의 기술적 특징들이 반영된 다양한 실시예들이 당해 기술분야의 통상적인 지식을 가진 자에 의해 이하 상술할 본 발명의 상세한 설명을 기반으로 도출되고 이해될 수 있다.The above-described aspects of the present invention are merely some of the preferred embodiments of the present invention, and various embodiments reflecting the technical features of the present invention will be described in detail by those skilled in the art. Based on the description, it can be derived and understood.
본 발명의 실시예들에 따르면 다음과 같은 효과가 있다.According to embodiments of the present invention has the following effects.
첫째, mmWave 시스템에서 효율적으로 데이터 통신을 지원할 수 있다.First, data communication can be efficiently supported in mmWave systems.
둘째, mmWave TAG 안의 mmWave 기지국들에 함께 위치한(collocated) mmWave 셀들이 밀집한 밀도로 배치 되었을 경우에, mmWave 셀들 내의 mmWave 단말의 분포를 고려하여 무선 자원을 할당함으로써 mmWave 셀 설정시에 셀 내 간섭을 줄일 수 있다. Second, when the mmWave cells collocated at mmWave base stations in the mmWave TAG are deployed at a dense density, radio frequency allocation is taken into account in consideration of the distribution of mmWave terminals in mmWave cells to reduce intra-cell interference in mmWave cell setup. Can be.
셋째, mmWave 링크의 불안정성을 고려하여, 다중 링크 자원을 할당할 수 있다.Third, in consideration of instability of the mmWave link, multiple link resources can be allocated.
본 발명의 실시예들에서 얻을 수 있는 효과는 이상에서 언급한 효과들로 제한되지 않으며, 언급하지 않은 또 다른 효과들은 이하의 본 발명의 실시예들에 대한 기재로부터 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에게 명확하게 도출되고 이해될 수 있다. 즉, 본 발명을 실시함에 따른 의도하지 않은 효과들 역시 본 발명의 실시예들로부터 당해 기술분야의 통상의 지식을 가진 자에 의해 도출될 수 있다.Effects obtained in the embodiments of the present invention are not limited to the above-mentioned effects, and other effects not mentioned above are usually described in the technical field to which the present invention pertains from the description of the embodiments of the present invention. Can be clearly derived and understood by those who have That is, unintended effects of practicing the present invention may also be derived from those skilled in the art from the embodiments of the present invention.
본 발명에 관한 이해를 돕기 위해 상세한 설명의 일부로 포함되고, 첨부된 도면들은 본 발명에 대한 다양한 실시예들을 제공한다. 또한, 첨부된 도면들은 상세한 설명과 함께 본 발명의 실시 형태들을 설명하기 위해 사용된다.It is included as part of the detailed description to assist in understanding the present invention, and the accompanying drawings provide various embodiments of the present invention. In addition, the accompanying drawings are used to describe embodiments of the present invention in conjunction with the detailed description.
도 1은 물리 채널들 및 이들을 이용한 신호 전송 방법을 설명하기 위한 도면이다.1 is a diagram illustrating a physical channel and a signal transmission method using the same.
도 2는 무선 프레임의 구조의 일례를 나타내는 도면이다.2 is a diagram illustrating an example of a structure of a radio frame.
도 3는 하향링크 슬롯에 대한 자원 그리드(resource grid)를 예시한 도면이다.3 is a diagram illustrating a resource grid for a downlink slot.
도 4는 상향링크 서브 프레임의 구조의 일례를 나타내는 도면이다.4 is a diagram illustrating an example of a structure of an uplink subframe.
도 5는 하향링크 서브 프레임의 구조의 일례를 나타내는 도면이다.5 is a diagram illustrating an example of a structure of a downlink subframe.
도 6은 mmWave에서 사용하는 안테나 포트의 일례를 나타내는 도면이다.6 is a diagram illustrating an example of an antenna port used in mmWave.
도 7는 무지향성 안테나와 지향성 안테나가 커버 가능한 셀 반경의 일례를 나타내는 도면이다.7 is a diagram illustrating an example of a cell radius that can be covered by the omnidirectional antenna and the directional antenna.
도 8은 송신 빔 스캐닝에 대한 수신 빔 스캐닝의 초기 단계의 일례를 나타내는 도면이다.8 is a diagram illustrating an example of an initial stage of receive beam scanning for transmit beam scanning.
도 9는 수신 로브 인덱스가 수신측에서 고정된 후 송신단에서 빔 스캐닝을 수행하는 방법 중 하나를 나타내는 도면이다.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.
도 10은 mmWave 스몰 셀 구조를 설명하기 위한 도면이다.10 is a view for explaining the mmWave small cell structure.
도 11은 아날로그 빔포밍시에 mmWave 셀 구조를 설명하기 위한 도면이다.FIG. 11 is a diagram for explaining an mmWave cell structure in analog beamforming. FIG.
도 12는 하나의 mmWave 기지국에서 mmWave 단말들의 각 셀 내의 분포 모습 및 mmWave 셀 구성을 설명하기 위한 도면이다.12 is a view for explaining the distribution and configuration of mmWave cell in each cell of mmWave terminals in one mmWave base station.
도 13은 mmWave 기지국들에 구성되는 멀티 링크 셀 및 빔 타이밍을 설명하기 위한 도면이다.FIG. 13 is a diagram for describing a multi link cell and beam timing configured in mmWave base stations.
도 14는 mmWave 단말에 설정 가능한 다중 mmWave 링크를 설명하기 위한 도면이다.14 is a diagram for describing multiple mmWave links that can be set in an mmWave terminal.
도 15는 다른 링크 접속 패턴을 원하는 mmWave 단말이 있는 경우에 다중 링크 설정의 모호성을 설명하기 위한 도면이다.FIG. 15 is a diagram for explaining ambiguity of multi-link configuration when there is an mmWave terminal that desires another link connection pattern.
도 16은 mmWave 기지국에 다중 링크 연결을 위한 다중 mmWave 셀을 구성하는 방법을 설명하기 위한 도면이다.FIG. 16 is a diagram illustrating a method of configuring multiple mmWave cells for multiple link connection to an mmWave base station.
도 17은 mmWave 다중 셀 자원을 할당하는 방법 중 하나를 설명하기 위한 도면이다.FIG. 17 illustrates one method of allocating mmWave multi-cell resources.
도 18은 다중 mmWave 링크 환경에서 링크 불안정성을 줄이기 위한 자원 할당 방법을 설명하기 위한 도면이다.18 is a diagram illustrating a resource allocation method for reducing link instability in a multi-mmWave link environment.
도 19는 다중 mmWave 링크 환경에서 링크 불안정성을 줄이기 위한 자원 할당 방법을 설명하기 위한 다른 도면이다.19 is another diagram for explaining a resource allocation method for reducing link instability in a multi-mmWave link environment.
도 20에서 설명하는 장치는 도 1 내지 도 19에서 설명한 방법들이 구현될 수 있는 수단이다.The apparatus described in FIG. 20 is a means by which the methods described in FIGS. 1 to 19 may be implemented.
이하의 실시예들은 본 발명의 구성요소들과 특징들을 소정 형태로 결합한 것들이다. 각 구성요소 또는 특징은 별도의 명시적 언급이 없는 한 선택적인 것으로 고려될 수 있다. 각 구성요소 또는 특징은 다른 구성요소나 특징과 결합되지 않은 형태로 실시될 수 있다. 또한, 일부 구성요소들 및/또는 특징들을 결합하여 본 발명의 실시예를 구성할 수도 있다. 본 발명의 실시예들에서 설명되는 동작들의 순서는 변경될 수 있다. 어느 실시예의 일부 구성이나 특징은 다른 실시예에 포함될 수 있고, 또는 다른 실시예의 대응하는 구성 또는 특징과 교체될 수 있다.The following embodiments combine the components and features of the present invention in a predetermined form. 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. In addition, 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.
도면에 대한 설명에서, 본 발명의 요지를 흐릴 수 있는 절차 또는 단계 등은 기술하지 않았으며, 당업자의 수준에서 이해할 수 있을 정도의 절차 또는 단계는 또한 기술하지 아니하였다.In the description of the drawings, procedures or steps which may obscure the gist of the present invention are not described, and procedures or steps that can be understood by those skilled in the art are not described.
명세서 전체에서, 어떤 부분이 어떤 구성요소를 "포함(comprising 또는 including)"한다고 할 때, 이는 특별히 반대되는 기재가 없는 한 다른 구성요소를 제외하는 것이 아니라 다른 구성요소를 더 포함할 수 있는 것을 의미한다. 또한, 명세서에 기재된 "…부", "…기", "모듈" 등의 용어는 적어도 하나의 기능이나 동작을 처리하는 단위를 의미하며, 이는 하드웨어나 소프트웨어 또는 하드웨어 및 소프트웨어의 결합으로 구현될 수 있다. 또한, "일(a 또는 an)", "하나(one)", "그(the)" 및 유사 관련어는 본 발명을 기술하는 문맥에 있어서(특히, 이하의 청구항의 문맥에서) 본 명세서에 달리 지시되거나 문맥에 의해 분명하게 반박되지 않는 한, 단수 및 복수 모두를 포함하는 의미로 사용될 수 있다.Throughout the specification, when a part is said to "comprising" (or including) a component, this means that it may further include other components, except to exclude other components unless specifically stated otherwise. do. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have. Also, "a or an", "one", "the", and the like are used differently in the context of describing the present invention (particularly in the context of the following claims). Unless otherwise indicated or clearly contradicted by context, it may be used in the sense including both the singular and the plural.
본 명세서에서 본 발명의 실시예들은 기지국과 이동국 간의 데이터 송수신 관계를 중심으로 설명되었다. 여기서, 기지국은 이동국과 직접적으로 통신을 수행하는 네트워크의 종단 노드(terminal node)로서의 의미가 있다. 본 문서에서 기지국에 의해 수행되는 것으로 설명된 특정 동작은 경우에 따라서는 기지국의 상위 노드(upper node)에 의해 수행될 수도 있다.In the present specification, embodiments of the present invention have been described based on data transmission / reception relations between a base station and a mobile station. Here, 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.
즉, 기지국을 포함하는 다수의 네트워크 노드들(network nodes)로 이루어지는 네트워크에서 이동국과의 통신을 위해 수행되는 다양한 동작들은 기지국 또는 기지국 이외의 다른 네트워크 노드들에 의해 수행될 수 있다. 이때, '기지국'은 고정국(fixed station), Node B, eNode B(eNB), 발전된 기지국(ABS: Advanced Base Station) 또는 억세스 포인트(access point) 등의 용어에 의해 대체될 수 있다.That is, 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. In this case, 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.
또한, 본 발명의 실시예들에서 단말(Terminal)은 사용자 기기(UE: User Equipment), 이동국(MS: Mobile Station), 가입자 단말(SS: Subscriber Station), 이동 가입자 단말(MSS: Mobile Subscriber Station), 이동 단말(Mobile Terminal) 또는 발전된 이동단말(AMS: Advanced Mobile Station) 등의 용어로 대체될 수 있다.Further, in embodiments of the present invention, 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).
또한, 송신단은 데이터 서비스 또는 음성 서비스를 제공하는 고정 및/또는 이동 노드를 말하고, 수신단은 데이터 서비스 또는 음성 서비스를 수신하는 고정 및/또는 이동 노드를 의미한다. 따라서, 상향링크에서는 이동국이 송신단이 되고, 기지국이 수신단이 될 수 있다. 마찬가지로, 하향링크에서는 이동국이 수신단이 되고, 기지국이 송신단이 될 수 있다.Also, the transmitting end refers to a fixed and / or mobile node that provides a data service or a voice service, and 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.
본 발명의 실시예들은 무선 접속 시스템들인 IEEE 802.xx 시스템, 3GPP(3rd Generation Partnership Project) 시스템, 3GPP LTE 시스템 및 3GPP2 시스템 중 적어도 하나에 개시된 표준 문서들에 의해 뒷받침될 수 있으며, 특히, 본 발명의 실시예들은 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321 및 3GPP TS 36.331 문서들에 의해 뒷받침 될 수 있다. 즉, 본 발명의 실시예들 중 설명하지 않은 자명한 단계들 또는 부분들은 상기 문서들을 참조하여 설명될 수 있다. 또한, 본 문서에서 개시하고 있는 모든 용어들은 상기 표준 문서에 의해 설명될 수 있다.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. In addition, all terms disclosed in the present document can be described by the above standard document.
이하, 본 발명에 따른 바람직한 실시 형태를 첨부된 도면을 참조하여 상세하게 설명한다. 첨부된 도면과 함께 이하에 개시될 상세한 설명은 본 발명의 예시적인 실시형태를 설명하고자 하는 것이며, 본 발명이 실시될 수 있는 유일한 실시형태를 나타내고자 하는 것이 아니다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.
또한, 본 발명의 실시예들에서 사용되는 특정(特定) 용어들은 본 발명의 이해를 돕기 위해서 제공된 것이며, 이러한 특정 용어의 사용은 본 발명의 기술적 사상을 벗어나지 않는 범위에서 다른 형태로 변경될 수 있다.In addition, specific terms used in the embodiments of the present invention are provided to help the understanding of the present invention, and the use of the specific terms may be changed into other forms without departing from the technical spirit of the present invention. .
이하에서는 본 발명의 실시예들이 사용될 수 있는 무선 접속 시스템의 일례로 3GPP LTE/LTE-A 시스템에 대해서 설명한다.Hereinafter, a 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.
이하의 기술은 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) 등과 같은 다양한 무선 접속 시스템에 적용될 수 있다.The following techniques include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and the like. It can be applied to various radio access systems.
CDMA는 UTRA(Universal Terrestrial Radio Access)나 CDMA2000과 같은 무선 기술(radio technology)로 구현될 수 있다. TDMA는 GSM(Global System for Mobile communications)/GPRS(General Packet Radio Service)/EDGE(Enhanced Data Rates for GSM Evolution)와 같은 무선 기술로 구현될 수 있다. OFDMA는 IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA(Evolved UTRA) 등과 같은 무선 기술로 구현될 수 있다.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). 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).
UTRA는 UMTS(Universal Mobile Telecommunications System)의 일부이다. 3GPP LTE(Long Term Evolution)은 E-UTRA를 사용하는 E-UMTS(Evolved UMTS)의 일부로써, 하향링크에서 OFDMA를 채용하고 상향링크에서 SC-FDMA를 채용한다. LTE-A(Advanced) 시스템은 3GPP LTE 시스템이 개량된 시스템이다. 본 발명의 기술적 특징에 대한 설명을 명확하게 하기 위해, 본 발명의 실시예들을 3GPP LTE/LTE-A 시스템을 위주로 기술하지만 IEEE 802.16e/m 시스템 등에도 적용될 수 있다.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. The LTE-A (Advanced) system is an improved system of the 3GPP LTE system. In order to clarify the description of the technical features of the present invention, 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.
1. 3GPP LTE/LTE_A 시스템1.3GPP LTE / LTE_A System
무선 접속 시스템에서 단말은 하향링크(DL: Downlink)를 통해 기지국으로부터 정보를 수신하고, 상향링크(UL: Uplink)를 통해 기지국으로 정보를 전송한다. 기지국과 단말이 송수신하는 정보는 일반 데이터 정보 및 다양한 제어 정보를 포함하고, 이들이 송수신 하는 정보의 종류/용도에 따라 다양한 물리 채널이 존재한다.In a wireless access system, 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.
1.1 시스템 일반1.1 System General
도 1은 본 발명의 실시예들에서 사용될 수 있는 물리 채널들 및 이들을 이용한 신호 전송 방법을 설명하기 위한 도면이다.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.
전원이 꺼진 상태에서 다시 전원이 켜지거나, 새로이 셀에 진입한 단말은 S11 단계에서 기지국과 동기를 맞추는 등의 초기 셀 탐색 (Initial cell search) 작업을 수행한다. 이를 위해 단말은 기지국으로부터 주동기 채널 (P-SCH: Primary Synchronization Channel) 및 부동기 채널 (S-SCH: Secondary Synchronization Channel)을 수신하여 기지국과 동기를 맞추고, 셀 ID 등의 정보를 획득한다.When the power is turned off again or a new cell enters the cell, the initial cell search operation such as synchronizing with the base station is performed in step S11. To this end, 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.
그 후, 단말은 기지국으로부터 물리방송채널 (PBCH: Physical Broadcast Channel) 신호를 수신하여 셀 내 방송 정보를 획득할 수 있다.Thereafter, the terminal may receive a physical broadcast channel (PBCH) signal from the base station to obtain broadcast information in a cell.
한편, 단말은 초기 셀 탐색 단계에서 하향링크 참조 신호 (DL RS: Downlink Reference Signal)를 수신하여 하향링크 채널 상태를 확인할 수 있다.On the other hand, the terminal may receive a downlink reference signal (DL RS) in the initial cell search step to confirm the downlink channel state.
초기 셀 탐색을 마친 단말은 S12 단계에서 물리하향링크제어채널 (PDCCH: Physical Downlink Control Channel) 및 물리하향링크제어채널 정보에 따른 물리하향링크공유 채널 (PDSCH: Physical Downlink Control Channel)을 수신하여 조금 더 구체적인 시스템 정보를 획득할 수 있다.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.
이후, 단말은 기지국에 접속을 완료하기 위해 이후 단계 S13 내지 단계 S16과 같은 임의 접속 과정 (Random Access Procedure)을 수행할 수 있다. 이를 위해 단말은 물리임의접속채널 (PRACH: Physical Random Access Channel)을 통해 프리앰블 (preamble)을 전송하고(S13), 물리하향링크제어채널 및 이에 대응하는 물리하향링크공유 채널을 통해 프리앰블에 대한 응답 메시지를 수신할 수 있다(S14). 경쟁 기반 임의 접속의 경우, 단말은 추가적인 물리임의접속채널 신호의 전송(S15) 및 물리하향링크제어채널 신호 및 이에 대응하는 물리하향링크공유 채널 신호의 수신(S16)과 같은 충돌해결절차 (Contention Resolution Procedure)를 수행할 수 있다.Subsequently, the terminal may perform a random access procedure as in steps S13 to S16 to complete the access to the base station. To this end, 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). In case of contention-based random access, 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).
상술한 바와 같은 절차를 수행한 단말은 이후 일반적인 상/하향링크 신호 전송 절차로서 물리하향링크제어채널 신호 및/또는 물리하향링크공유채널 신호의 수신(S17) 및 물리상향링크공유채널 (PUSCH: Physical Uplink Shared Channel) 신호 및/또는 물리상향링크제어채널 (PUCCH: Physical Uplink Control Channel) 신호의 전송(S18)을 수행할 수 있다.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).
단말이 기지국으로 전송하는 제어정보를 통칭하여 상향링크 제어정보(UCI: Uplink Control Information)라고 지칭한다. UCI는 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) 정보 등을 포함한다.The control information transmitted from the terminal to the base station is collectively referred to as uplink control information (UCI). UCI includes Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK (HARQ-ACK / NACK), Scheduling Request (SR), Channel Quality Indication (CQI), Precoding Matrix Indication (PMI), and Rank Indication (RI) information. .
LTE 시스템에서 UCI는 일반적으로 PUCCH를 통해 주기적으로 전송되지만, 제어정보와 트래픽 데이터가 동시에 전송되어야 할 경우 PUSCH를 통해 전송될 수 있다. 또한, 네트워크의 요청/지시에 의해 PUSCH를 통해 UCI를 비주기적으로 전송할 수 있다.In the LTE system, 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. In addition, the UCI may be aperiodically transmitted through the PUSCH by the request / instruction of the network.
도 2는 본 발명의 실시예들에서 사용되는 무선 프레임의 구조를 나타낸다.2 shows a structure of a radio frame used in embodiments of the present invention.
도 2(a)는 타입 1 프레임 구조(frame structure type 1)를 나타낸다. 타입 1 프레임 구조는 전이중(full duplex) FDD(Frequency Division Duplex) 시스템과 반이중(half duplex) FDD 시스템 모두에 적용될 수 있다.2 (a) shows a frame structure type 1. The type 1 frame structure can be applied to both full duplex Frequency Division Duplex (FDD) systems and half duplex FDD systems.
하나의 무선 프레임(radio frame)은 Tf = 307200*Ts = 10ms의 길이를 가지고, Tslot = 15360*Ts = 0.5ms의 균등한 길이를 가지며 0부터 19의 인덱스가 부여된 20개의 슬롯으로 구성된다. 하나의 서브프레임은 2개의 연속된 슬롯으로 정의되며, i 번째 서브프레임은 2i 와 2i+1에 해당하는 슬롯으로 구성된다. 즉, 무선 프레임(radio frame)은 10개의 서브프레임(subframe)으로 구성된다. 하나의 서브프레임을 전송하는 데 걸리는 시간을 TTI(transmission time interval)이라 한다. 여기서, Ts 는 샘플링 시간을 나타내고, Ts=1/(15kHz×2048)=3.2552×10-8(약 33ns)로 표시된다. 슬롯은 시간 영역에서 복수의 OFDM 심볼 또는 SC-FDMA 심볼을 포함하고, 주파수 영역에서 복수의 자원블록(Resource Block)을 포함한다.One radio frame has a length of Tf = 307 200 * Ts = 10 ms, an equal length of Tslot = 15360 * Ts = 0.5 ms, and consists of 20 slots indexed from 0 to 19. 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). Here, Ts represents a sampling time and is represented by Ts = 1 / (15kHz × 2048) = 3.2552 × 10-8 (about 33ns). 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.
하나의 슬롯은 시간 영역에서 복수의 OFDM(orthogonal frequency division multiplexing) 심볼을 포함한다. 3GPP LTE는 하향링크에서 OFDMA를 사용하므로 OFDM 심볼은 하나의 심볼 구간(symbol period)을 표현하기 위한 것이다. OFDM 심볼은 하나의 SC-FDMA 심볼 또는 심볼 구간이라고 할 수 있다. 자원 블록(resource block)은 자원 할당 단위이고, 하나의 슬롯에서 복수의 연속적인 부반송파(subcarrier)를 포함한다.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.
전이중 FDD 시스템에서는 각 10ms 구간 동안 10개의 서브프레임은 하향링크 전송과 상향링크 전송을 위해 동시에 이용될 수 있다. 이때, 상향링크와 하향링크 전송은 주파수 영역에서 분리된다. 반면, 반이중 FDD 시스템의 경우 단말은 전송과 수신을 동시에 할 수 없다.In a full-duplex FDD system, 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. On the other hand, in the case of a half-duplex FDD system, the terminal cannot transmit and receive at the same time.
상술한 무선 프레임의 구조는 하나의 예시에 불과하며, 무선 프레임에 포함되는 서브 프레임의 수 또는 서브 프레임에 포함되는 슬롯의 수, 슬롯에 포함되는 OFDM 심볼의 수는 다양하게 변경될 수 있다.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.
도 2(b)는 타입 2 프레임 구조(frame structure type 2)를 나타낸다. 타입 2 프레임 구조는 TDD 시스템에 적용된다. 하나의 무선 프레임(radio frame)은 Tf = 307200*Ts = 10ms의 길이를 가지며, 153600*Ts = 5ms 길이를 가지는 2개의 하프프레임(half-frame)으로 구성된다. 각 하프프레임은 30720*Ts = 1ms의 길이를 가지는 5개의 서브프레임으로 구성된다. i 번째 서브프레임은 2i 와 2i+1에 해당하는 각 Tslot = 15360*Ts = 0.5ms의 길이를 가지는 2개의 슬롯으로 구성된다. 여기에서, Ts 는 샘플링 시간을 나타내고, Ts=1/(15kHz×2048)=3.2552×10-8(약 33ns)로 표시된다. 2 (b) shows a frame structure type 2. Type 2 frame structure is applied to the TDD system. One radio frame has a length of Tf = 307200 * Ts = 10ms and consists of two half-frames having a length of 153600 * Ts = 5ms. Each half frame consists of five subframes having a length of 30720 * Ts = 1ms. The i-th subframe consists of two slots each having a length of Tslot = 15360 * Ts = 0.5ms corresponding to 2i and 2i + 1. Here, Ts represents a sampling time and is represented by Ts = 1 / (15 kHz x 2048) = 3.2552 x 10 -8 (about 33 ns).
타입 2 프레임에는 DwPTS(Downlink Pilot Time Slot), 보호구간(GP: Guard Period), UpPTS(Uplink Pilot Time Slot)인 3가지의 필드로 구성되는 특별 서브프레임을 포함한다. 여기서, DwPTS는 단말에서의 초기 셀 탐색, 동기화 또는 채널 추정에 사용된다. UpPTS는 기지국에서의 채널 추정과 단말의 상향 전송 동기를 맞추는 데 사용된다. 보호구간은 상향링크와 하향링크 사이에 하향링크 신호의 다중경로 지연으로 인해 상향링크에서 생기는 간섭을 제거하기 위한 구간이다. 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). Here, 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.
다음 표 1는 특별 프레임의 구성(DwPTS/GP/UpPTS의 길이)을 나타낸다.Table 1 below shows the structure of the special frame (length of DwPTS / GP / UpPTS).
표 1
Figure PCTKR2016004415-appb-T000001
 Table 1
Figure PCTKR2016004415-appb-T000001
도 3은 본 발명의 실시예들에서 사용될 수 있는 하향링크 슬롯에 대한 자원 그리드(resource grid)를 예시한 도면이다.3 is a diagram illustrating a resource grid for a downlink slot that can be used in embodiments of the present invention.
도 3을 참조하면, 하나의 하향링크 슬롯은 시간 영역에서 복수의 OFDM 심볼을 포함한다. 여기서, 하나의 하향링크 슬롯은 7개의 OFDM 심볼을 포함하고, 하나의 자원 블록은 주파수 영역에서 12개의 부 반송파를 포함하는 것을 예시적으로 기술하나, 이에 한정되는 것은 아니다.Referring to FIG. 3, one downlink slot includes a plurality of OFDM symbols in the time domain. Here, one downlink slot includes seven OFDM symbols, and one resource block includes 12 subcarriers in a frequency domain, but is not limited thereto.
자원 그리드 상에서 각 요소(element)를 자원 요소(resource element)하고, 하나의 자원 블록은 12 × 7 개의 자원 요소를 포함한다. 하향링크 슬롯에 포함되는 자원 블록들의 수 NDL은 하향링크 전송 대역폭(bandwidth)에 종속한다. 상향링크 슬롯의 구조는 하향링크 슬롯의 구조와 동일할 수 있다.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.
도 4는 본 발명의 실시예들에서 사용될 수 있는 상향링크 서브 프레임의 구조를 나타낸다.4 shows a structure of an uplink subframe that can be used in embodiments of the present invention.
도 4를 참조하면, 상향링크 서브 프레임은 주파수 영역에서 제어 영역과 데이터 영역으로 나눌 수 있다. 제어 영역에는 상향링크 제어 정보를 나르는 PUCCH가 할당된다. 데이터 영역은 사용자 데이터를 나르는 PUSCH가 할당된다. 단일 반송파 특성을 유지하기 위해 하나의 단말은 PUCCH와 PUSCH를 동시에 전송하지 않는다. 하나의 단말에 대한 PUCCH에는 서브 프레임 내에 RB 쌍이 할당된다. RB 쌍에 속하는 RB들은 2개의 슬롯들의 각각에서 서로 다른 부 반송파를 차지한다. 이러한 PUCCH에 할당된 RB 쌍은 슬롯 경계(slot boundary)에서 주파수 도약(frequency hopping)된다고 한다.Referring to FIG. 4, 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. In the data area, a PUSCH carrying user data is allocated. In order to maintain a single carrier characteristic, 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.
도 5는 본 발명의 실시예들에서 사용될 수 있는 하향링크 서브 프레임의 구조를 나타낸다.5 shows a structure of a downlink subframe that can be used in embodiments of the present invention.
도 5를 참조하면, 서브 프레임내의 첫번째 슬롯에서 OFDM 심볼 인덱스 0부터 최대 3개의 OFDM 심볼들이 제어 채널들이 할당되는 제어 영역(control region)이고, 나머지 OFDM 심볼들은 PDSCH이 할당되는 데이터 영역(data region)이다. 3GPP LTE에서 사용되는 하향링크 제어 채널의 일례로 PCFICH(Physical Control Format Indicator Channel), PDCCH, PHICH(Physical Hybrid-ARQ Indicator Channel) 등이 있다.Referring to FIG. 5, 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. One example of 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).
PCFICH는 서브 프레임의 첫 번째 OFDM 심볼에서 전송되고, 서브 프레임 내에 제어 채널들의 전송을 위하여 사용되는 OFDM 심볼들의 수(즉, 제어 영역의 크기)에 관한 정보를 나른다. PHICH는 상향 링크에 대한 응답 채널이고, HARQ(Hybrid Automatic Repeat Request)에 대한 ACK(Acknowledgement)/NACK(Negative-Acknowledgement) 신호를 나른다. PDCCH를 통해 전송되는 제어 정보를 하향링크 제어정보(DCI: downlink control information)라고 한다. 하향링크 제어정보는 상향링크 자원 할당 정보, 하향링크 자원 할당 정보 또는 임의의 단말 그룹에 대한 상향링크 전송(Tx) 파워 제어 명령을 포함한다.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.
1.2 PDCCH(Physical Downlink Control Channel)1.2 Physical Downlink Control Channel (PDCCH)
1.2.1 PDCCH 일반1.2.1 PDCCH General
PDCCH는 DL-SCH(Downlink Shared Channel)의 자원 할당 및 전송 포맷(즉, 하향링크 그랜트(DL-Grant)), UL-SCH(Uplink Shared Channel)의 자원 할당 정보(즉, 상향링크 그랜트(UL-Grant)), PCH(Paging Channel)에서의 페이징(paging) 정보, DL-SCH에서의 시스템 정보, PDSCH에서 전송되는 랜덤 액세스 응답(random access response)과 같은 상위 레이어(upper-layer) 제어 메시지에 대한 자원 할당, 임의의 단말 그룹 내 개별 단말들에 대한 전송 파워 제어 명령들의 집합, VoIP(Voice over IP)의 활성화 여부에 관한 정보 등을 나를 수 있다.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.
복수의 PDCCH가 제어영역 내에서 전송될 수 있으며, 단말은 복수의 PDCCH를 모니터링할 수 있다. PDCCH는 하나 또는 몇몇 연속적인 CCE(control channel elements)의 집합(aggregation)으로 구성된다. 하나 또는 몇몇 연속적인 CCE의 집합으로 구성된 PDCCH는 서브블록 인터리빙(subblock interleaving)을 거친 후에 제어 영역을 통해 전송될 수 있다. CCE는 무선채널의 상태에 따른 부호화율을 PDCCH에게 제공하기 위해 사용되는 논리적 할당 단위이다. CCE는 복수의 자원 요소 그룹(REG: resource element group)에 대응된다. CCE의 수와 CCE들에 의해 제공되는 부호화율의 연관 관계에 따라 PDCCH의 포맷 및 가능한 PDCCH의 비트수가 결정된다A 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). The PDCCH composed of one or several consecutive CCEs may be transmitted through the control region after subblock interleaving. 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.
1.2.2 PDCCH 구조1.2.2 PDCCH Structure
복수의 단말에 대한 다중화된 복수의 PDCCH가 제어영역 내에서 전송될 수 있다. PDCCH는 하나 또는 2 이상의 연속적인 CCE의 집합(CCE aggregation)으로 구성된다. CCE는 4개의 자원 요소로 구성된 REG의 9개의 세트에 대응하는 단위를 말한다. 각 REG에는 4개의 QPSK(Quadrature Phase Shift Keying) 심볼이 매핑 된다. 참조 신호(RS: Reference Signal)에 의하여 점유된 자원 요소들은 REG에 포함되지 않는다. 즉, OFDM 심볼 내에서 REG의 총 개수는 셀 특정 참조 신호가 존재하는지 여부에 따라 달라질 수 있다. 4개의 자원 요소를 하나의 그룹에 매핑하는 REG의 개념은 다른 하향링크 제어 채널(예를 들어, PCFICH 또는 PHICH)에도 적용될 수 있다. PCFICH 또는 PHICH에 할당되지 않는 REG를 NREG라 하면 시스템에서 이용 가능한 CCE의 개수는 NCCE = floor(NREG/9)이며, 각 CCE는 0부터 NCCE-1 까지 인덱스를 가진다.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. Four Quadrature Phase Shift Keying (QPSK) symbols are mapped to each REG. Resource elements occupied by a reference signal (RS) are not included in the REG. That is, the total number of REGs in the OFDM symbol may vary depending on whether a cell specific reference signal exists. The concept of REG, which maps four resource elements to one group, can also be applied to other downlink control channels (eg, PCFICH or PHICH). If REG not assigned to PCFICH or PHICH is N REG , the number of CCEs available in the system is N CCE = floor (N REG / 9), and each CCE has an index from 0 to N CCE -1.
단말의 디코딩 프로세스를 단순화하기 위해서, n개의 CCE를 포함하는 PDCCH 포맷은 n의 배수와 동일한 인덱스를 가지는 CCE부터 시작될 수 있다. 즉, CCE 인덱스가 i인 경우 imod(n) = 0 을 만족하는 CCE부터 시작될 수 있다.In order to simplify the decoding process of the UE, the PDCCH format including n CCEs may start with a CCE having an index equal to a multiple of n. That is, when the CCE index is i, it may start from a CCE satisfying imod (n) = 0.
기지국은 하나의 PDCCH 신호를 구성하기 위해 {1, 2, 4, 8} 개의 CCE들을 사용할 수 있으며, 이때의 {1, 2, 4, 8}은 CCE 집합 레벨(aggregation level)이라고 부른다. 특정 PDCCH의 전송을 위해 사용되는 CCE의 개수는 채널 상태에서 따라 기지국에 의하여 결정된다. 예를 들어, 양호한 하향링크 채널 상태(기지국에 가까운 경우)를 가지는 단말을 위한 PDCCH는 하나의 CCE만으로 충분할 수 있다. 반면, 좋지 않은 채널 상태(셀 경계에 있는 경우)를 가지는 단말의 경우는 8개의 CCE들이 충분한 강인함(robustness)을 위하여 요구될 수 있다. 게다가, PDCCH의 파워 레벨도 채널 상태에 매칭되어 조절될 수 있다.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. In addition, the power level of the PDCCH may also be adjusted to match the channel state.
다음 표 2는 PDCCH 포맷을 나타내며, CCE 집합 레벨에 따라 표 2과 같이 4가지의 PDCCH 포맷이 지원된다.Table 2 below shows a PDCCH format, and four PDCCH formats are supported as shown in Table 2 according to the CCE aggregation level.
표 2
PDCCH 포맷 CCE 개수 (n) REG 개수 PDCCH 비트 수
0 1 9 72
1 2 18 144
2 4 36 288
3 8 72 576
TABLE 2
PDCCH Format CCE Count (n) REG Count PDCCH Bit Count
0 One 9 72
One 2 18 144
2 4 36 288
3 8 72 576
단말마다 CCE 집합 레벨이 다른 이유는 PDCCH에 실리는 제어정보의 포맷 또는 MCS(Modulation and Coding Scheme) 레벨이 다르기 때문이다. MCS 레벨은 데이터 코딩에 사용되는 코드 레이트(code rate)와 변조 차수(modulation order)를 의미한다. 적응적인 MCS 레벨은 링크 적응(link adaptation)을 위해 사용된다. 일반적으로 제어정보를 전송하는 제어채널에서는 3~4개 정도의 MCS 레벨을 고려할 수 있다.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. The 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.
제어정보의 포맷을 설명하면, PDCCH를 통해 전송되는 제어정보를 하향링크 제어정보(DCI)라고 한다. DCI 포맷에 따라 PDCCH 페이로드(payload)에 실리는 정보의 구성이 달라질 수 있다. PDCCH 페이로드는 정보 비트(information bit)를 의미한다. 다음 표 3은 DCI 포맷에 따른 DCI를 나타낸다. Referring to the format of the control information, control information transmitted through the PDCCH is referred to as downlink control information (DCI). According to the DCI format, 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.
표 3
DCI 포맷 내용
Format 0 Resource grants for PUSCH transmissions (uplink)
Format 1 Resource assignments for single codeword PDSCH transmission (transmission modes 1, 2 and 7)
Format 1A Compact signaling of resource assignments for sigle codeword PDSCH (all modes)
Format 1B Compact resource assignments for PDSCH using rank-1 closed loop precoding (mode 6)
Format 1C Very compact resource assignments for PDSCH (e.g., paging/broadcast system information)
Format 1D Compact resource assignments for PDSCH using multi-user MIMO(mode 5)
Format 2 Resource assignments for PDSCH for closed loop MIMO operation (mode 4)
Format 2A resource assignments for PDSCH for open loop MIMO operation (mode 3)
Format 3/3A Power control commands for PUCCH and PUSCH with 2-bit/1-bit power adjustment
Format 4 Scheduling of PUSCH in one UL cell with multi-antenna port transmission mode
TABLE 3
DCI format Contents
Format
0 Resource grants for PUSCH transmissions (uplink)
Format 1 Resource assignments for single codeword PDSCH transmission ( transmission modes 1, 2 and 7)
Format 1A Compact signaling of resource assignments for sigle codeword PDSCH (all modes)
Format 1B Compact resource assignments for PDSCH using rank-1 closed loop precoding (mode 6)
Format 1C Very compact resource assignments for PDSCH (eg, paging / broadcast system information)
Format 1D Compact resource assignments for PDSCH using multi-user MIMO (mode 5)
Format 2 Resource assignments for PDSCH for closed loop MIMO operation (mode 4)
Format 2A resource assignments for PDSCH for open loop MIMO operation (mode 3)
Format 3 / 3A Power control commands for PUCCH and PUSCH with 2-bit / 1-bit power adjustment
Format
4 Scheduling of PUSCH in one UL cell with multi-antenna port transmission mode
표 3을 참조하면, DCI 포맷으로는 PUSCH 스케줄링을 위한 포맷 0, 하나의 PDSCH 코드워드의 스케줄링을 위한 포맷 1, 하나의 PDSCH 코드워드의 간단한(compact) 스케줄링을 위한 포맷 1A, DL-SCH의 매우 간단한 스케줄링을 위한 포맷 1C, 폐루프(Closed-loop) 공간 다중화(spatial multiplexing) 모드에서 PDSCH 스케줄링을 위한 포맷 2, 개루프(Openloop) 공간 다중화 모드에서 PDSCH 스케줄링을 위한 포맷 2A, 상향링크 채널을 위한 TPC(Transmission Power Control) 명령의 전송을 위한 포맷 3 및 3A가 있다. DCI 포맷 1A는 단말에 어떤 전송 모드가 설정되어도 PDSCH 스케줄링을 위해 사용될 수 있다.Referring to Table 3, 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 There are formats 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.
DCI 포맷에 따라 PDCCH 페이로드 길이가 달라질 수 있다. 또, PDCCH 페이로드의 종류와 그에 따른 길이는 간단한(compact) 스케줄링인지 여부 또는 단말에 설정된 전송 모드(transmission mode) 등에 의해 달라질 수 있다.The PDCCH payload length may vary depending on the DCI format. In addition, 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.
전송 모드는 단말이 PDSCH를 통한 하향링크 데이터를 수신하기 위해 설정(configuration)될 수 있다. 예를 들어, PDSCH를 통한 하향링크 데이터는 단말에 대한 스케줄된 데이터(scheduled data), 페이징, 랜덤 액세스 응답 또는 BCCH를 통한 브로드캐스트 정보 등이 있다. PDSCH를 통한 하향링크 데이터는 PDCCH를 통해 시그널되는 DCI 포맷과 관계가 있다. 전송 모드는 상위 계층 시그널링(예를 들어, RRC(Radio Resource Control) 시그널링)을 통해 단말에 반정적으로(semi-statically) 설정될 수 있다. 전송 모드는 싱글 안테나 전송(Single antenna transmission) 또는 멀티 안테나(Multi-antenna) 전송으로 구분할 수 있다.The transmission mode may be configured for the UE to receive downlink data through the PDSCH. For example, 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.
단말은 상위 계층 시그널링을 통해 반정적(semi-static)으로 전송 모드가 설정된다. 예를 들어, 멀티 안테나 전송에는 전송 다이버시티(Transmit diversity), 개루프(Open-loop) 또는 폐루프(Closed-loop) 공간 다중화(Spatial multiplexing), MU-MIMO(Multi-user-Multiple Input Multiple Output) 또는 빔 형성(Beamforming) 등이 있다. 전송 다이버시티는 다중 송신 안테나에서 동일한 데이터를 전송하여 전송 신뢰도를 높이는 기술이다. 공간 다중화는 다중 송신 안테나에서 서로 다른 데이터를 동시에 전송하여 시스템의 대역폭을 증가시키지 않고 고속의 데이터를 전송할 수 있는 기술이다. 빔 형성은 다중 안테나에서 채널 상태에 따른 가중치를 가하여 신호의 SINR(Signal to Interference plus Noise Ratio)을 증가시키는 기술이다.The terminal is set to a semi-static transmission mode through higher layer signaling. For example, multi-antenna transmission includes transmit diversity, open-loop or closed-loop spatial multiplexing, and multi-user-multiple input multiple outputs. ) Or 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.
DCI 포맷은 단말에 설정된 전송 모드에 종속된다(depend on). 단말은 자신에게 설정된 전송 모드에 따라 모니터링하는 참조(Reference) DCI 포맷이 있다. 단말에 설정되는 전송 모드는 다음과 같이 10개의 전송 모드를 가질 수 있다.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.
(1) 전송모드 1: 단일 안테나 포트; 포트 0(1) transmission mode 1: single antenna port; Port 0
(2) 전송모드 2: 전송 다이버시티(Transmit Diversity)(2) Transmission Mode 2: Transmit Diversity
(3) 전송모드 3: 개루프 공간 다중화 (Open-loop Spatial Multiplexing)(3) Transmission Mode 3: Open-loop Spatial Multiplexing
(4) 전송모드 4: 폐루프 공간 다중화 (Closed-loop Spatial Multiplexing)(4) Transmission Mode 4: Closed-loop Spatial Multiplexing
(5) 전송모드 5: 다중 사용자 MIMO(5) Transmission Mode 5: Multi-User MIMO
(6) 전송모드 6: 폐루프, 랭크 = 1 프리코딩(6) Transmission mode 6: closed loop, rank = 1 precoding
(7) 전송모드 7: 코드북에 기반하지 않는, 단일 레이어 전송을 지원하는 프리코딩(7) Transmission mode 7: Precoding supporting single layer transmission not based on codebook
(8) 전송모드 8: 코드북에 기반하지 않는, 두 개까지 레이어를 지원하는 프리코딩(8) Transmission mode 8: Precoding supporting up to two layers not based on codebook
(9) 전송모드 9: 코드북에 기반하지 않는, 여덟 개까지 레이어를 지원하는 프리코딩(9) Transmission mode 9: Precoding supporting up to eight layers not based on codebook
(10) 전송모드 10: 코드북에 기반하지 않는, CoMP를 위해 사용되는, 여덟 개까지 레이어를 지원하는 프리코딩(10) Transmission mode 10: precoding supporting up to eight layers, used for CoMP, not based on codebook
1.2.3 PDCCH 전송1.2.3 PDCCH Transmission
기지국은 단말에게 전송하려는 DCI에 따라 PDCCH 포맷을 결정하고, 제어 정보에 CRC(Cyclic Redundancy Check)를 붙인다. CRC에는 PDCCH의 소유자(owner)나 용도에 따라 고유한 식별자(예를 들어, RNTI(Radio Network Temporary Identifier))가 마스킹된다. 특정의 단말을 위한 PDCCH라면 단말의 고유한 식별자(예를 들어, C-RNTI(Cell-RNTI))가 CRC에 마스킹될 수 있다. 또는 페이징 메시지를 위한 PDCCH라면 페이징 지시 식별자(예를 들어, P-RNTI(Paging-RNTI))가 CRC에 마스킹될 수 있다. 시스템 정보, 더욱 구체적으로 시스템 정보 블록(SIB: System Information Block)를 위한 PDCCH라면 시스템 정보 식별자(예를 들어, SI-RNTI(System Information RNTI))가 CRC에 마스킹될 수 있다. 단말의 랜덤 액세스 프리앰블의 전송에 대한 응답인 랜덤 액세스 응답을 지시하기 위하여 RA-RNTI(random access-RNTI)가 CRC에 마스킹될 수 있다.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. In the CRC, a unique identifier (for example, a Radio Network Temporary Identifier (RNTI)) is masked according to an owner or a purpose of the PDCCH. If it is a PDCCH for a specific terminal, a unique identifier (eg, C-RNTI (Cell-RNTI)) of the terminal may be masked to the CRC. Alternatively, if the PDCCH is for a paging message, a paging indication identifier (eg, P-RNTI (P-RNTI)) may be masked to the CRC. If the system information, more specifically, the PDCCH for the System Information Block (SIB), a system information identifier (eg, a System Information RNTI (SI-RNTI)) may be masked to the CRC. A random access-RNTI (RA-RNTI) may be masked to the CRC to indicate a random access response that is a response to the transmission of the random access preamble of the UE.
이어, 기지국은 CRC가 부가된 제어정보를 채널 코딩을 수행하여 부호화된 데이터(coded data)를 생성한다. 이때, MCS 레벨에 따른 코드 레이트로 채널 코딩을 수행할 수 있다. 기지국은 PDCCH 포맷에 할당된 CCE 집합 레벨에 따른 전송률 매칭(rate matching)을 수행하고, 부호화된 데이터를 변조하여 변조 심볼들을 생성한다. 이때, MCS 레벨에 따른 변조 서열을 사용할 수 있다. 하나의 PDCCH를 구성하는 변조 심볼들은 CCE 집합 레벨이 1, 2, 4, 8 중 하나일 수 있다. 이후, 기지국은 변조 심볼들을 물리적인 자원요소에 맵핑(CCE to RE mapping)한다.Subsequently, the base station performs channel coding on the control information added with the CRC to generate coded data. In this case, 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. At this time, 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. Thereafter, the base station maps modulation symbols to physical resource elements (CCE to RE mapping).
1.2.4 블라인드 디코딩(BS: Blind Decoding)1.2.4 Blind Decoding (BS)
하나의 서브프레임 내에서 복수의 PDCCH가 전송될 수 있다. 즉, 하나의 서브프레임의 제어영역은 인덱스 0 ~ NCCE,k-1 을 가지는 복수의 CCE로 구성된다. 여기서, NCCE,k는 k번째 서브프레임의 제어 영역 내의 총 CCE의 개수를 의미한다. 단말은 매 서브프레임마다 복수의 PDCCH들을 모니터링한다. 여기서, 모니터링이란 단말이 모니터링되는 PDCCH 포맷에 따라 PDCCH들의 각각의 디코딩을 시도하는 것을 말한다.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. Here, 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.
서브프레임 내에서 할당된 제어영역에서 기지국은 단말에게 해당하는 PDCCH가 어디에 있는지에 관한 정보를 제공하지 않는다. 단말은 기지국으로부터 전송된 제어채널을 수신하기 위해서 자신의 PDCCH가 어느 위치에서 어떤 CCE 집합 레벨이나 DCI 포맷으로 전송되는지 알 수 없으므로, 단말은 서브프레임 내에서 PDCCH 후보(candidate)들의 집합을 모니터링하여 자신의 PDCCH를 찾는다. 이를 블라인드 디코딩(BD)이라 한다. 블라인드 디코딩은 단말이 CRC 부분에 자신의 단말 식별자(UE ID)를 디 마스킹(De-Masking) 시킨 후, CRC 오류를 검토하여 해당 PDCCH가 자신의 제어채널인지 여부를 확인하는 방법을 말한다.In the control region allocated in the subframe, the base station does not provide information on where the PDCCH corresponding to the UE is. In order to receive the control channel transmitted from the base station, the UE cannot know where the PDCCH is transmitted in which CCE aggregation level or DCI format. Therefore, the UE monitors the aggregation of PDCCH candidates in a subframe. Find the PDCCH. This is called blind decoding (BD). 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.
활성 모드(active mode)에서 단말은 자신에게 전송되는 데이터를 수신하기 위해 매 서브프레임의 PDCCH를 모니터링한다. DRX 모드에서 단말은 매 DRX 주기의 모니터링 구간에서 깨어나(wake up) 모니터링 구간에 해당하는 서브프레임에서 PDCCH를 모니터링한다. PDCCH의 모니터링이 수행되는 서브프레임을 non-DRX 서브프레임이라 한다.In the active mode, the UE monitors the PDCCH of every subframe in order to receive data transmitted to the UE. In the DRX mode, 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.
단말은 자신에게 전송되는 PDCCH를 수신하기 위해서는 non-DRX 서브프레임의 제어영역에 존재하는 모든 CCE에 대해 블라인드 디코딩을 수행해야 한다. 단말은 어떤 PDCCH 포맷이 전송될지 모르므로, 매 non-DRX 서브프레임 내에서 PDCCH의 블라인드 디코딩이 성공할 때까지 가능한 CCE 집단 레벨로 PDCCH를 모두 디코딩해야 한다. 단말은 자신을 위한 PDCCH가 몇 개의 CCE를 사용하는지 모르기 때문에 PDCCH의 블라인드 디코딩이 성공할 때까지 가능한 모든 CCE 집단 레벨로 검출을 시도해야 한다.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.
LTE 시스템에서는 단말의 블라인드 디코딩을 위해서 서치 스페이스(SS: Search Space) 개념을 정의한다. 서치 스페이스는 단말이 모니터링하기 위한 PDCCH 후보 세트를 의미하며, 각 PDCCH 포맷에 따라 상이한 크기를 가질 수 있다. 서치 스페이스는 공용 서치 스페이스(CSS: Common Search Space)와 단말 특정 서치 스페이스(USS: UE-specific/Dedicated Search Space)로 구성될 수 있다.In the LTE system, 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).
공용 서치 스페이스의 경우, 모든 단말이 공용 서치 스페이스의 크기에 대하여 알 수 있으나, 단말 특정 서치 스페이스는 각 단말마다 개별적으로 설정될 수 있다. 따라서, 단말은 PDCCH를 디코딩하기 위해 단말 특정 서치 스페이스 및 공용 서치 스페이스를 모두 모니터링해야 하며, 따라서 하나의 서브프레임에서 최대 44번의 블라인드 디코딩(BD)을 수행하게 된다. 여기에는 상이한 CRC 값(예를 들어, C-RNTI, P-RNTI, SI-RNTI, RA-RNTI)에 따라 수행하는 블라인드 디코딩은 포함되지 않는다.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).
서치 스페이스의 제약으로 인하여, 기지국은 주어진 서브프레임 내에서 PDCCH를 전송하고자 하는 단말들 모두에게 PDCCH를 전송하기 위한 CCE 자원이 확보될 수 없는 경우가 발생할 수 있다. 왜냐하면, CCE 위치가 할당되고 남은 자원들은 특정 단말의 서치 스페이스 내에 포함되지 않을 수 있기 때문이다. 다음 서브프레임에도 계속될 수 있는 이러한 장벽을 최소화하기 위하여 단말 특정 도약(hopping) 시퀀스가 단말 특정 서치 스페이스의 시작 지점에 적용될 수 있다.Due to the limitation of the search space, 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.
표 4는 공용 서치 스페이스와 단말 특정 서치 스페이스의 크기를 나타낸다.Table 4 shows the sizes of the common search space and the terminal specific search space.
표 4
PDCCH 포맷 CCE 개수 (n) CSS에서 후보 개수 USS에서 후보 개수
0 1 - 6
1 2 - 6
2 4 4 2
3 8 2 2
Table 4
PDCCH Format CCE Count (n) Candidate count in CSS Candidate Count in USS
0 One - 6
One 2 - 6
2 4 4 2
3 8 2 2
블라인드 디코딩을 시도하는 횟수에 따른 단말의 부하를 경감하기 위해, 단말은 정의된 모든 DCI 포맷에 따른 서치를 동시에 수행하지 않는다. 구체적으로, 단말은 단말 특정 서치 스페이스(USS)에서 항상 DCI 포맷 0 과 1A에 대한 서치를 수행한다. 이때, DCI 포맷 0과 1A는 동일한 크기를 가지나, 단말은 PDCCH에 포함된 DCI 포맷 0과 1A를 구분하는데 사용되는 플래그(flag for format 0/format 1A differentiation)를 이용하여 DCI 포맷을 구분할 수 있다. 또한, 단말에 DCI 포맷 0과 DCI 포맷 1A외에 다른 DCI 포맷이 요구될 수 있는데, 그 일례로 DCI 포맷 1, 1B, 2가 있다.In order to reduce the load of the UE according to the number of blind decoding attempts, 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.
공용 서치 스페이스(CSS)에서 단말은 DCI 포맷 1A와 1C를 서치할 수 있다. 또한 단말은 DCI 포맷 3 또는 3A를 서치하도록 설정될 수 있으며, DCI 포맷 3과 3A는 DCI 포맷 0과 1A와 동일한 크기를 가지나, 단말은 단말 특정 식별자가 아닌 다른 식별자에 의하여 스크램블된 CRC를 이용하여 DCI 포맷을 구별할 수 있다.In the common search space (CSS), the UE may search for DCI formats 1A and 1C. In addition, 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.
서치 스페이스
Figure PCTKR2016004415-appb-I000001
는 집합 레벨
Figure PCTKR2016004415-appb-I000002
에 따른 PDCCH 후보 세트를 의미한다. 서치 스페이스의 PDCCH 후보 세트 m에 따른 CCE는 다음과 같은 수학식 1에 의해 결정될 수 있다.Search space
Figure PCTKR2016004415-appb-I000001
Set level
Figure PCTKR2016004415-appb-I000002
PDCCH candidate set according to the. The CCE according to the PDCCH candidate set m of the search space may be determined by Equation 1 below.
수학식 1
Figure PCTKR2016004415-appb-M000001
 Equation 1
Figure PCTKR2016004415-appb-M000001
여기서, M(L)은 서치 스페이스에서 모니터하기 위한 CCE 집합 레벨 L에 따른 PDCCH 후보들의 개수를 나타내며, m=0, ...,
Figure PCTKR2016004415-appb-I000003
-1 이다. i는 PDCCH 에서 각 PDCCH 후보에서 개별 CCE를 지정하는 인덱스로서 i = 0, ..., L-1이다. k=floor(
Figure PCTKR2016004415-appb-I000004
/2) 이며, ns는 무선 프레임 내에서 슬롯 인덱스를 나타낸다. Here, M (L) represents the number of PDCCH candidates according to the CCE aggregation level L for monitoring in the search space, and m = 0, ...,
Figure PCTKR2016004415-appb-I000003
-1. i is an index designating an individual CCE in each PDCCH candidate in the PDCCH, and i = 0, ..., L-1. k = floor (
Figure PCTKR2016004415-appb-I000004
/ 2), and n s represents a slot index in a radio frame.
상술한 바와 같이, 단말은 PDCCH를 디코딩하기 위해 단말 특정 서치 스페이스 및 공용 서치 스페이스를 모두 모니터링한다. 여기서, 공용 서치 스페이스(CSS)는 {4, 8}의 집합 레벨을 갖는 PDCCH들을 지원하고, 단말 특정 서치 스페이스(USS)는 {1, 2, 4, 8}의 집합 레벨을 갖는 PDCCH들을 지원한다. 표 5는 단말에 의하여 모니터링되는 PDCCH 후보를 나타낸다. As described above, the UE monitors both the UE-specific search space and the common search space to decode the PDCCH. Here, the common search space (CSS) supports PDCCHs having an aggregation level of {4, 8}, and the UE specific search space (USS) supports PDCCHs having an aggregation level of {1, 2, 4, 8}. . Table 5 shows PDCCH candidates monitored by the UE.
표 5
Figure PCTKR2016004415-appb-T000002
 Table 5
Figure PCTKR2016004415-appb-T000002
수학식 1을 참조하면, 공용 서치 스페이스의 경우 2개의 집합 레벨, L=4 및 L=8에 대해 Yk는 0으로 설정된다. 반면, 집합 레벨 L에 대해 단말 특정 서치 스페이스의 경우 Yk는 수학식 2와 같이 정의된다. Referring to Equation 1, Y k is set to 0 for two aggregation levels, L = 4 and L = 8 for a common search space. On the other hand, for the UE-specific search space for the aggregation level L, Y k is defined as in Equation 2.
수학식 2
Figure PCTKR2016004415-appb-M000002
 Equation 2
Figure PCTKR2016004415-appb-M000002
여기서,
Figure PCTKR2016004415-appb-I000005
이며, nRNTI는 RNTI 값을 나타낸다. 또한, A = 39827이고, D = 65537이다.here,
Figure PCTKR2016004415-appb-I000005
And n RNTI represents an RNTI value. Further, A = 39827 and D = 65537.
2. 밀리미터 웨이브(mmWave)2. Millimeter Wave (mmWave)
본 발명은 mmWave 링크 고유의 위치 특정 선(site specific ray) 특성 정보 검출 및 풍부한 분석 가능 선(resolvable ray) 검출을 위한 신호 송수신 방법 및 이를 지원하는 장치들에 관한 것이다. 기존의 짧은 mmWave 셀 범위로 인하여, 송수신 안테나의 빔 이득 획득(antenna beam gain)을 위해 빔포밍(beamforming) 수행이 필수적인 상황이었다. 따라서, mmWave 스캐닝 기법으로도 빔포밍 기반의 빔 스캐닝 기법이 제안되어 왔다. 하지만, 이러한 기술들은 빔 스캐닝에 따른 오버헤드로 인하여 송수신 스캐닝 지연이 길어지는 단점이 있다.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.
본 발명에서 제안하는 레이 스캐닝(Ray scanning) 기법은 mmWave 환경의 고유 특징을 검출함으로써 빔 스캐닝 기법에 따른 큰 오버헤드를 줄이는데 효과가 있다. 또한, 단말의 송수신 빔 스캐닝으로 인한 정보는 채널의 고유 특성 정보(예를 들어, PDP(power delay profile) 또는 PAS(power azimuth spectrum) 등)가 아니므로, 채널 고유의 정보 획득 및 응용을 위하여 사용 할 수 있다.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. In addition, 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.
2.1 안테나 포트2.1 antenna port
도 6은 mmWave에서 사용하는 안테나 포트의 일례를 나타내는 도면이다.6 is a diagram illustrating an example of an antenna port used in mmWave.
안테나 포트는 물리적 안테나에 대한 가상적인 개념이다. 안테나 포트로 내보내지는 출력은 반드시 참조 신호(RS: Reference Signal)를 포함한다. 하나의 논리적 안테나 포트로 나가는 출력은 RS를 포함해서 단말이 RS를 검출하여 채널을 추정해서 수신할 수 있는 안테나 스트림(antenna stream) 단위로 볼 수 있다.Antenna ports are a virtual concept of physical antennas. The output sent to the antenna port necessarily includes a reference signal (RS). 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.
따라서 하나의 안테나 스트림이 2개 이상의 물리적 안테나로 전송되거나 또는 하나의 안테나 스트림이 공간 프리코딩(spatial precoding; 송신 빔포밍의 하나) 되어 여러 개의 물리적 안테나를 통해 전송되든지 상관없이 단말은 하나의 안테나 포트를 가정하여 수신할 수 있다.Therefore, regardless of whether one antenna stream is transmitted to two or more physical antennas, or one antenna stream is spatial precoded (one of transmit beamforming) and transmitted through multiple physical antennas, the terminal may transmit one antenna port. Can be assumed to be received.
도 6과 같이 물리적 안테나는 안테나 포트와 별개의 매핑으로 이루어져 있으며, 벤더(vender)에 따라 물리적 안테나와 안테나 포트 간의 매핑이 정해진다. 따라서, 물리적 안테나의 구현 문제는 고려할 필요 없이 안테나 포트당 신호 또는 데이터의 전송 방법에 대한 기술들이 고려되고 있다.As shown in FIG. 6, 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.
2.2 셀 서치 (측정, 평가, 검출) 방법2.2 Cell Search (Measurement, Evaluation, Detection) Method
본 발명의 실시예들에서 셀 서치라는 용어는 측정, 평가 검출 과정들의 조합을 의미하는 집합적인 용어이다. 셀 서치는 단말이 셀 선택을 수행하기 전에 제일 먼저 수행하는 과정이므로 셀 선택 과정에 매우 긴밀하게 연관된다. 또한, 셀 서치 과정은 유휴 모드 상태의 단말의 에너지 소모에 매우 많은 영향을 미친다.In the embodiments of the present invention, 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.
셀 서치에 사용되는 용어로서, DRX 사이틀은 일종의 타이머이다. 측정/평가/검출 과정은 DRX 사이클의 횟수로서 특정되는 기간 동안 수행된다. 유휴 모드의 경우, DRX 사이클은 SIB1 메시지를 통해 네트워크로부터 결정된다.As used in cell search, 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. In idle mode, the DRX cycle is determined from the network via a SIB1 message.
'스캔'이라는 용어는 규격 문서들에서 명시적으로 규정되어 있지 않지만, 대부분의 단말들이 이 과정을 수행한다. 이 과정은 특정 주파수에 대한 튜닝 과정이고 가장 간단한 신호 품질(예를 들어, RSSI 등)을 측정하는 절차이다. 보통 측정, 평가 과정 이전에 단말은 스캔 과정을 먼저 수행하고, 다음 과정(예를 들어, 측정, 평가)을 수행하기 위해 ‘적은 후보 개수’를 선택한다. 만약 단말이 모든 가능한 주파수 및 대역에 대해서 바로 측정, 평가 과정을 수행한다면, 단말은 너무 많은 시간 소모 및 심각한 전력 소모를 격게된다.The term 'scan' is not explicitly defined in the specification documents, but most terminals perform this process. This is a tuning process for a specific frequency and the simplest signal quality (eg RSSI) measurement. 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.
‘측정’ 과정은 RSRP, RSRQ를 측정하는 과정으로, 모든 비 서빙 셀 측정에 대해, LTE/LTE-A 규격의 36.133에 정의된 바에 따라 수행된다. ‘평가’ 과정은 ‘측정’ 과정의 결과에 기반하여 셀 선택 기준을 확인하기 위한 과정이다. ‘검출’ 과정은 특정 주파수의 튜닝 및 동기화 과정 및 셀들의 기본 정보를 디코딩하는 과정이다.'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.
이하에서는 WCDMA 시스템에 대해서 초기 스캔 및 셀 서치 과정의 일례를 설명한다. WCDMA 시스템은 LTE/LTE-A 시스템의 이전 버전으로 이하에서 설명하는 내용은 LTE/LTE-A 시스템에도 적용 가능하다.Hereinafter, an example of an initial scan and cell search process for a WCDMA system will be described. 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.
단말의 전원을 처음 켜거나 단말이 셀 커버리지를 벗어나면, 단말은 새로운 셀에 대한 검출 및 서치를 수행한다. 단말은 어느 셀의 어느 주파수로 캠프온(camp on)할지 알지 못하므로 블라인드 디코딩을 수행해야 한다. 예를 들어, 단말이 WCDMA 밴드 I을 지원하는 경우를 가정한다. 이때, 단말 인근의 기지국은 주파수 채널 10562 내지 10838을 사용할 수 있다. 즉, 단말은 276 개의 가능한 주파수들을 사용할 수 있다.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.
이러한 가정 하에서, 단말은 먼저 지원되는 모든 채널들 각각에 대해서 RSSI를 측정한다. RSSI는 에너지/파워 어떠한 것에 대한 단말이 측정할 수 있는 측정값이다. RSSI 측정은 채널 코딩 과정을 필요로 하지 않는다. 따라서, 단말은 네트워크에 대해서 어떠한 것도 알 필요가 없다. 즉, 단말은 물리 셀 식별자를 검출하기 위해 WCDMA 시스템에서는 PCPICH, LTE 시스템에서는 동기/참조 신호를 디코딩할 필요가 없다. 단말은 단지 각 채널의 전력을 측정하면 된다. 단말이 각 채널에 대해서 RSSI를 측정함으로써, 단말은 측정한 RSSI를 가지고 각 채널 번호들의 리스트를 생성할 수 있다.Under this assumption, 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. Thus, 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. As the terminal measures the RSSI for each channel, the terminal may generate a list of channel numbers with the measured RSSI.
다음으로, 단말은 생성한 채널 번호들에 대한 리스트를 이용하여 RSSI가 임계치보다 높은 채널들을 구분한다. 이후, 단말은 캠프온 하기 위해 적절한 후보를 찾기 위해 다음 단계들을 수행한다.Next, 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.
단말은 PCPICH 또는 동기/참조 신호를 디코딩하여 물리 셀 식별자를 검출하고, 전력을 측정한다. 단말은 검출한 물리 셀 식별자들에 대해서 후보 셀 리스트를 작성한다.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.
작성한 후보 셀 식별자 리스트를 기반으로, 단말은 모든 후보 셀들에 대해서 MIB를 디코딩한다.Based on the created candidate cell identifier list, the terminal decodes the MIB for all candidate cells.
유심 정보 및 후보 셀 리스트를 기반으로, 단말은 실제 어떤 셀이 가장 캠프 온하기 적합한 셀인지를 확인하고, 시스템 정보 및 등록 과정을 수행한다.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.
2.3 mmWave의 문제점2.3 mmWave problems
기존의 레이 스캐닝(Ray scanning) 기법으로는 mmWave의 무지향(Omni) 안테나 특성으로 인해 작은 셀 경계를 가지며, 분석 가능한 레이(resolvable Ray)가 작은 셀 지역에서만 검출 될 수 밖에 없다. 따라서, 레이 스캐닝 시에 빔포밍 이득의 도움 없이 어떻게 분석 가능한 레이의 검출 확률을 높일 것인지가 중요한 문제이다. 또한, mmWave 링크는 단말의 위치 환경에 따라 링크 환경에도 민감하게 변하기 때문에, 위치 특정한 초기 환경 정보의 획득도 중요한 문제이다.Conventional ray scanning technique has a small cell boundary due to the omni-directional antenna characteristic of mmWave, and the resolvable ray can only be detected in a small cell region. Therefore, it is an important issue how to increase the detection probability of the analytical ray without the aid of the beamforming gain during ray scanning. In addition, since the mmWave link is sensitive to the link environment according to the location environment of the terminal, acquisition of location-specific initial environment information is also an important problem.
도 7는 무지향성 안테나와 지향성 안테나가 커버 가능한 셀 반경의 일례를 나타내는 도면이다.7 is a diagram illustrating an example of a cell radius that can be covered by the omnidirectional antenna and the directional antenna.
도 7을 참조하면, 무지향성 안테나가 커버하는 셀의 범위는 지향성 안테나가 커버하는 셀 범위보다 넓다. mmWave에서 지향성 안테나를 사용시, 즉 빔포밍을 활용시 빔 포밍의 범위 이득이 -20dB 정도 줄어드는 문제가 있다. 따라서 무지향성 안테나를 사용하는 것이 바람직하나, mmWave의 경우 사용자 위치에 따라 채널 특성이 급변하는 문제점이 있다.Referring to FIG. 7, the range of cells covered by the omnidirectional antenna is wider than the range of cells covered by the directional antenna. When 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.
무지향성 안테나를 사용하는 mmWave 기술의 특성상 상술한 문제점이 있다. 따라서, 본 발명에서는 이러한 문제점을 극복하고 지향성 안테나가 커버하는 범위까지 무지향성 안테나가 커버할 수 있는 셀 범위를 늘리기 위한 방법들을 제안한다.The above-mentioned problem is caused by the characteristics of mmWave technology using an omnidirectional antenna. Accordingly, 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.
2.4 지향성 안테나에 대한 스캐닝 방법2.4 Scanning Method for Directional Antennas
2.4.1 빔 스캐닝 방법2.4.1 Beam Scanning Method
이하에서는 빔 스캐닝 방법들에 대해서 간단히 설명한다.Hereinafter, beam scanning methods will be briefly described.
도 8은 송신 빔 스캐닝에 대한 수신 빔 스캐닝의 초기 단계의 일례를 나타내는 도면이고, 도 9는 수신 로브 인덱스가 수신측에서 고정된 후 송신단에서 빔 스캐닝을 수행하는 방법 중 하나를 나타내는 도면이다.FIG. 8 is a diagram illustrating an example of an initial stage of reception beam scanning for transmission beam scanning, and 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.
빔 스캐닝의 초기 단계에서 기지국의 송신 빔 코드북이 결정되면, 해당 송신 빔은 고정한 상태로 수신측 즉, 단말이 수신 빔 스캐닝을 360도로 돌아가면서 각 빔에 따른 PDP (Power Delay Prifile)을 도출한다. 이때, 단말은 검출한 PDP 중 가장 전력이 큰 레이(Ray)를 가지고 있는 수신 로브(lobe)의 인덱스를 선택한다. 이때, 로브란 안테나에서 방사되는 전파의 에너지 분포가 여러 방향으로 나뉘어져 있는 경우 각각의 방사군을 의미한다. 즉, 빔 스캐닝시 빔의 일 형태를 의미한다.When the transmission beam codebook of the base station is determined in the initial stage of beam scanning, 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. In this case, the terminal selects an index of a reception lobe having a ray having the largest power among the detected PDPs. In this case, 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.
다음 수학식 3은 단말이 검출하는 각 로브의 SNR을 계산하기 위해 사용된다. Equation 3 below is used to calculate the SNR of each lobe detected by the UE.
수학식 3
Figure PCTKR2016004415-appb-M000003
 Equation 3
Figure PCTKR2016004415-appb-M000003
수학식 3에서
Figure PCTKR2016004415-appb-I000006
는 송신빔 k에 대한 i 번째 로브의 무선 채널을 의미하고, wi는 프리코딩 행렬을 의미하며, pi는 수신 전력을 의미하며, 시그마(σ)는 노이즈의 크기를 의미하며, 시그마의 제곱은 노이즈의 전력을 의미한다.In equation (3)
Figure PCTKR2016004415-appb-I000006
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 (σ) is the magnitude of the noise, and sigma is the noise Means power.
고정된 송신 빔 로브에 대한 수신 빔 스캐닝이 완료되는 시간을 도 3과 같이
Figure PCTKR2016004415-appb-I000007
라고 정의 할 때,
Figure PCTKR2016004415-appb-I000008
값은 다음 수학식 4와 같이 결정될 수 있다.As shown in FIG. 3, the time at which reception beam scanning for the fixed transmission beam lobe is completed is completed.
Figure PCTKR2016004415-appb-I000007
When you define that,
Figure PCTKR2016004415-appb-I000008
The value may be determined as in Equation 4 below.
수학식 4
Figure PCTKR2016004415-appb-M000004
 Equation 4
Figure PCTKR2016004415-appb-M000004
수학식 4에서
Figure PCTKR2016004415-appb-I000009
는 수신단에서 반복하여 빔 스캐닝을 하는데 필요한 최대 지연 시간을 의미하는 초과 지연 확산(excess delay spread) 값이며,
Figure PCTKR2016004415-appb-I000010
는 전송 지연 값이고,
Figure PCTKR2016004415-appb-I000011
는 각 수신 빔 로브에 대한 PDP 측정 시간 및 강한 레이 검출 시간을 의미하며, N는 수신 측 빔 로브의 개수를 의미한다.In equation (4)
Figure PCTKR2016004415-appb-I000009
Is an excess delay spread value that indicates the maximum delay time required for the beam scanning to be repeatedly performed at the receiving end.
Figure PCTKR2016004415-appb-I000010
Is the transmission delay value,
Figure PCTKR2016004415-appb-I000011
PDP measurement time and strong ray detection time for each reception beam lobe, N denotes the number of the receiving side beam lobe.
수신단은 전체 1~K까지의 송신 빔 로브를 360도 변화 시키면서, 위의 과정을 반복한다. 따라서, 수신단의 빔 스캐닝 완료 시간은
Figure PCTKR2016004415-appb-I000012
이다. 여기서 K는 전체 송신 빔의 개수를 의미한다.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
Figure PCTKR2016004415-appb-I000012
to be. Here, K means the total number of transmission beams.
도 9를 참조하면, 수신단인 단말이 빔 스캐닝을 완료하면 다시 mmWave 기지국으로 파일롯 신호를 전송한다. 이후, 단말은 송신 측 로브 인덱스를 결정하기 위해 360도 빔 스캐닝을 수행한다. 따라서, 송수신 빔 스캐닝이 완료되는 시간은
Figure PCTKR2016004415-appb-I000013
이 된다.Referring to FIG. 9, when 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
Figure PCTKR2016004415-appb-I000013
Becomes
다음 표 6은 빔 스캐닝 완료 시간 측정을 위한 파라미터를 정의한다.Table 6 below defines the parameters for measuring the beam scanning completion time.
표 6
Figure PCTKR2016004415-appb-T000003
 Table 6
Figure PCTKR2016004415-appb-T000003
만약, 빔 스캐닝을 수행하기 위한 파라미터들이 표 6과 같이 정의 된다면, 전체 송수신 빔 스캐닝 시간은 시간은 100*100*(1+5+670)+100*670 = 6.827 초(sec) 정도가 된다. 즉, 상당히 긴 시간의 오버헤드가 발생 함을 알 수 있다.If the parameters for performing the beam scanning are defined as shown in Table 6, the total transmission and reception beam scanning time is about 100 * 100 * (1 + 5 + 670) + 100 * 670 = 6.827 seconds (sec). In other words, it can be seen that a very long time overhead occurs.
그러나, mmWave 특성상 좁은 셀 커버리지 내에서 사용자의 순간적인 움직임에 따라 채널 특성이 가변한다. 그런데 빔 스캐닝을 위해 거의 7초 가량이 소모되면 변화된 채널 특성에 맞는 mmWave 서비스를 제공할 수 없는 문제점이 있다. 따라서, 일반적인 빔 스캐닝을 통한 mmWave 링크 연결을 위해서는 보다 간결한 처리 방법이 요구된다.However, due to mmWave characteristics, channel characteristics vary according to the instantaneous movement of a user within narrow cell coverage. However, if approximately seven seconds are consumed for beam scanning, there is a problem in that it is not possible to provide mmWave service for the changed channel characteristics. Therefore, a more compact processing method is required for mmWave link connection through general beam scanning.
2.4.2 mmWave 시스템에서 하이브리드 스캐닝 방법2.4.2 Hybrid Scanning Methods in mmWave Systems
계층적 빔 스캐닝과 같이 대략적 빔 스캐닝 이후의 정말한 빔 스캐닝 시 대략적 빔 스캐닝 과정에서 획득한 대략적 빔 벡터 정보를 활용 하기 어려운 단점을 보완하기 위해, 본 발명의 실시예들에서는 대략적 빔 스캐닝 대신에 채널 고유 정보를 획득하기 위해 레이 스캐닝을 수행할 수 있다. mmWave 단말은 레이 스캐닝을 통해 획득한 채널 고유 정보를 이용하여 후보 정밀 빔 벡터들을 획득하여 빔 스캐닝 오버헤드를 줄이고 전체 스캐닝 시간을 줄일 수 있다.In order to compensate for the difficulty of using the approximate beam vector information obtained in the approximate beam scanning process in the true beam scanning after the approximate beam scanning, such as hierarchical beam scanning, in embodiments of the present invention, 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.
이하에서는 하이브리드 스캐닝 방법에 대해서 간략히 설명한다.Hereinafter, the hybrid scanning method will be briefly described.
mmWave 기지국은 mmWave 단말과 시간 및 주파수 동기를 맞추기 위해 시간/주파수 동기 신호를 전송한다. 또한, mmWave 기지국은 셀 특정 포트 당 레이 스캐닝을 수행하기 위해 서로 다른 파일롯 신호들을 전송한다. 이때, 셀 특정 포트 당 서로 다른 파일롯 신호들은 반복하여 전송되거나 또는 일정 주기를 갖고 전송될 수 있다.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.
수신측인 단말은 수신한 파일롯 신호를 기반으로 셀 특정 포트 당 후 처리 과정 및 레이 스캐닝을 수행한다. 또한, 단말은 하이브리드 스캐닝에서 수행될 빔 포밍을 위한 빔 포밍 포트를 결정하기 위해 하나 이상의 후보 빔 벡터 집합들을 결정한다. 이후 단말은 기지국과 빔 포밍 포트별로 선택적인 빔 스캐닝을 수행할 수 있다.The receiving terminal performs post-processing and ray scanning per cell-specific port based on the received pilot signal. In addition, 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.
즉, 단말은 선택한 빔포밍 포트를 이용하여 기지국으로 파일롯 신호를 전송할 수 있다. 또한, 기지국은 단말이 전송하는 후보 빔포밍 포트 별로 전송되는 파일롯 신호를 검출함으로써 선택적인 빔 스캐닝을 수행할 수 있다.That is, the terminal may transmit a pilot signal to the base station using the selected beamforming port. In addition, the base station may perform selective beam scanning by detecting a pilot signal transmitted for each candidate beamforming port transmitted by the terminal.
하이브리드 스캐닝 방법으로, mmWave 시스템에서 기지국 및/또는 단말은 레이 스캐닝 및 빔 스캐닝을 함께 수행할 수 있다. 예를 들어, 기지국 및/또는 단말은 레이 스캐닝을 수행하기 위한 파일롯 신호를 송수신하고, 파일롯 신호를 이용하여 레이 스캐닝을 수행하며, 후보 빔 벡터 집합들을 획득하여, 후보 빔 벡터 집합들 내에서 빔 스캐닝을 수행할 수 있다.In a hybrid scanning method, in the mmWave system, the base station and / or the terminal may perform ray scanning and beam scanning together. For example, 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.
mmWave 기지국은 시간/주파수 동기 신호를 전송한 이후에, 기지국은 단말에서 기지국으로 전송할 파일롯 인덱스 및 자원 풀 인덱스를 각 단말에게 알려줄 수 있다. 이때, 파일롯 인덱스 및 자원 풀 인덱스는 레이 스캐닝 수행을 위해 각 단말들에 파일롯 신호를 전송할 때, 셀 특정 포트 당 파일롯 신호들에 CDM 방식으로 다중화되어 단말이 전송할 파일롯 신호 및 해당 파일롯 신호가 전송될 자원 위치를 지시한다.After the mmWave base station transmits the time / frequency synchronization signal, 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. In this case, when 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.
3. mmWave 시스템에서 자원 할당 방법3. How to Allocate Resources in mmWave Systems
3.1 mmWave 시스템 구성3.1 mmWave System Configuration
도 10은 mmWave 스몰 셀 구조를 설명하기 위한 도면이다.10 is a view for explaining the mmWave small cell structure.
mmWave 링크는 LoS(Line of Sight)/NLoS(Non-Line of Sight)간 천이, 인간 장애물 및/또는 수신 유저의 링크 방해(human body impact)등과 같은 원인으로 발생하는 링크 불안정성이 매우 크다. 따라서, mmWave 기지국들은 기존 스몰셀들의 배치보다 더 조밀하게 배치됨으로써 다중 링크 전송을 지원하는 것이 바람직하다.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.
도 10에서 가장 바깥쪽의 큰 경계를 갖는 것은 레가시 스몰셀이며, 중간의 경계를 갖는 것은 빔포밍이 수행된 mmWave 스몰 셀이다. 가작 작은 셀 경계를 갖는 것은 NLoS 상태의 스몰셀이다. 즉, mmWave 스몰셀은 기존 스몰셀에 대비하여 더 밀집한 셀 배치 구조를 갖는다.In FIG. 10, the outermost large boundary is the legacy small cell, and 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.
도 11은 아날로그 빔포밍시에 mmWave 셀 구조를 설명하기 위한 도면이다. 특히, 도 11(a)는 무지향성(Omni) mmWave 셀의 모습을 나타내며, 도 11(b)는 지향성(directional) mmWave 셀의 모습을 나타낸다.FIG. 11 is a diagram for explaining an mmWave cell structure in analog beamforming. FIG. In particular, FIG. 11 (a) shows the appearance of an omni mmWave cell, and FIG. 11 (b) shows the appearance of a directional mmWave cell.
mmWave 시스템에서 기지국은 경로 손실(PL)의 제한으로 인해 짧은 옴니 셀 범위를 갖는다. 따라서, 이러한 단점을 극복하기 위해 mmWave 시스템에서는 빔포밍을 수행하여, 빔 이득 획득을 통한 전파 도달 거리를 확장하고 방향성 안테나들의 공간적 재사용을 통해 처리량을 증대 시키는 것을 기본적 시스템 구성으로 고려한다.In the mmWave system, 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.
또한 mmWave의 짧은 파장 길이로 인해, 라지 스케일 배치(large scale array) 안테나의 온칩(on-chip) 형태의 하드웨어 설계가 용이한 장점이 있기 때문에, mmWave 셀들은 빔포밍 기반으로 공동 배치된(collocated) 다중 셀로 나타난다.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
도 12는 하나의 mmWave 기지국에서 mmWave 단말들의 각 셀 내의 분포 모습 및 mmWave 셀 구성을 설명하기 위한 도면이다.12 is a view for explaining the distribution and configuration of mmWave cell in each cell of mmWave terminals in one mmWave base station.
하나의 mmWave 기지국에서 mmWave 셀들은 기지국의 빔포밍 성능(beamforming capability)에 따라 구성될 수 있다. 이때, mmWave 셀의 형태는 다양한 크기와 모습으로 구성되는 다수의 mmWave 셀로 구성된다. 예를 들어, 도 12(a)와 같이 아날로그 빔 상으로 90도 성능(capability)을 가지는 mmWave 기지국은 3D 옴니 셀 반경 대비 7개(예를 들어, omni cell 및 6 directional cells)의 기하학(geometry) 기반 셀들이 하나의 mmWave 기지국에서 구성될 수 있다.The mmWave cells in one mmWave base station may be configured according to the beamforming capability of the base station. At this time, the shape of the mmWave cell is composed of a plurality of mmWave cells of various sizes and shapes. For example, an mmWave base station with 90 degrees of capability on an analog beam as shown in FIG. 12 (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.
예를 들어, 도 12(b)에서 유저(UE 01)는 옴니 셀에서 mmWave 기지국과 링크가 연결될 수 있지만, 어떤 방향의 빔포밍에서는(즉, 다른 mmWave 셀과는) 링크가 연결 되지 않을 수 있다. 즉, 송신 아날로그 빔포밍시에 mmWave 셀에서 송신 빔 구성과 mmWave 단말에서 수신 빔 구성에 따라 유저를 위한 링크가 연결될지 안될지 결정된다.For example, in FIG. 12 (b), 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.
수신 빔 구성은 mmWave 기지국의 구별된 mmWave 셀들 내에 위치한 mmWave 단말들을 묶어서 고려되는 것이 바람직하다. 따라서, mmWave 기지국은 각 mmWave 셀 내의 단말 그룹에 대한 셀 특정 전송 구성 정보와 각 그룹 안에 mmWave 유저들을 위한 mmWave 시스템 정보를 방송할 수 있다. 또는, 이러한 셀 특정 전송 구성 정보 및/또는 mmWave 시스템 정보는 레가시 시스템을 통해 미리 mmWave 단말들에 전송될 수 있다. 그리고 각 mmWave 셀 내에서 UE 특정하게 전송되는 구성이 필요하다.The receive beam configuration is preferably considered by tying mmWave terminals located in distinct mmWave cells of the mmWave base station. Accordingly, 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. Alternatively, such cell specific transmission configuration information and / or mmWave system information may be transmitted to mmWave terminals in advance through the legacy system. In addition, a configuration in which UE-specific transmission is performed in each mmWave cell is required.
도 12(b)는 각 mmWave 셀에 대한 자원 할당을 TDM 방식으로 수행하는 경우를 나타낸다. 도 12(b)를 참조하면, mmWave 셀에 대한 자원 할당은 TDM 방식으로 시간 축 상에서 수행되되, 옴니 셀과 지향성 셀에 대해서 별개로 수행될 수 있다. 예를 들어, SF#0은 mmWave 옴니 셀에 대한 자원이 할당되고, SF#2 내지 #7은 mmWave 지향성 셀에 대한 자원이 할당될 수 있다.12 (b) shows a case in which resource allocation for each mmWave cell is performed by the TDM scheme. Referring to FIG. 12 (b), resource allocation for the mmWave cell may be performed on the time axis in a TDM manner, but may be performed separately for the omni cell and the directional cell. For example, SF # 0 may be allocated resources for mmWave omni cells, and SF # 2 to # 7 may be allocated resources for mmWave directional cells.
3.2 mmWave 기지국 간의 다중 셀 구성3.2 Multiple Cell Configuration Between mmWave Base Stations
이하에서 설명하는 본 발명의 실시예들에서, 하나의 기지국 내에서 해당 기지국의 지원 가능한 빔폭 등을 기반으로 구성되는 mmWave 셀들을 하나의 TAG(Tracking Area Group)로 구성할 수 있다. 또는 특정 mmWave 단말에게 데이터를 전송하기 위해 협력 동작을 수행하는 mmWave 셀들을 하나의 TAG로 구성할 수 있다. 이때, mmWave 셀들은 서로 다른 mmWave 기지국에 속할 수 있다.In the embodiments of the present invention described below, mmWave cells configured based on the supportable beamwidth of the corresponding base station in one base station may be configured as one tracking area group (TAG). Alternatively, mmWave cells that perform cooperative operation to transmit data to a specific mmWave terminal may be configured as one TAG. In this case, mmWave cells may belong to different mmWave base stations.
mmWave 기지국들(e.g., mmWave TAG)이 각 mmWave 링크의 빔포밍 효과로 셀 내(inter site)에 위치한 셀들 간의 셀 내 간섭(inter cell interference)이 공간 멀티플렉싱을 통해 줄어들 수 있다. 이로 인해, mmWave 단말이 요구하는 전송률을 증가 시킬 수 있는 기회를 제공할 수 있다.In mmWave base stations (e.g., mmWave TAG) due to the beamforming effect of each mmWave link, inter-cell interference between cells located in an inter site can be reduced through spatial multiplexing. This may provide an opportunity to increase the transmission rate required by the mmWave terminal.
이런 환경에서 mmWave 시스템은 기존 스몰셀 대비 링크의 불안정성으로 인해 더 밀집한 밀도로 배치될 될 확률이 크다. 이때, mmWave 멀티 링크(도 12 참조)에 연결이 가능한 mmWave 단말이 요구하는 전송률을 달성하기 위해, mmWave 시스템에서는 멀티 링크 전송을 수행할 수 있다.In this environment, mmWave systems are more likely to be deployed at denser densities due to link instability compared to traditional small cells. At this time, in order to achieve a transmission rate required by the mmWave terminal capable of connecting to the mmWave multi-link (see FIG. 12), the mmWave system may perform multi-link transmission.
이러한 단말을 위해 밀집된 mmWave 기지국들은 한 타이밍에 셀 지역(cell area)이 겹치지 않도록 각각 전송 방향(즉, 빔포밍 방향)이 다르게 설정될 수 있다. 이를 통해, 각각의 기지국에 함께 구성된 mmWave 셀들을 피하고, 전송 시간 타이밍을 각 분할된 공간 셀에 매칭시켜 전송함으로써 셀 내 간섭을 줄일 수 있다.The dense mmWave base stations for such a terminal may have different transmission directions (ie, beamforming directions) so that cell areas do not overlap at one timing. In this way, the inter-cell interference can be reduced by avoiding the mmWave cells configured in each base station and by transmitting the transmission time timing to each divided spatial cell.
이때, mmWave 기지국은 불안정한 mmWave 링크로는 전송을 피하거나 전송량을 줄이는 방식으로 무선 자원을 할당할 수 있다. 또한 각 mmWave 기지국들이 동일 타이밍에 서로 다른 셀 방향을 형성함으로써 SINR 유지도 가능하다. 따라서, mmWave 기지국은 일정한 MCS 레벨로 데이터 전송이 가능하며, 각 링크에 대한 시간 및/또는 주파수 동기를 쉽게 맞출 수 있다.At this time, the mmWave base station may allocate radio resources in a manner that avoids transmission or reduces the transmission amount to the unstable mmWave link. In addition, each mmWave base station can form a different cell direction at the same timing to maintain SINR. Thus, the mmWave base station can transmit data at a constant MCS level and can easily synchronize time and / or frequency synchronization for each link.
도 13은 mmWave 기지국들에 구성되는 멀티 링크 셀 및 빔 타이밍을 설명하기 위한 도면이다.FIG. 13 is a diagram for describing a multi link cell and beam timing configured in mmWave base stations.
mmWave 시스템은 그 특성상 기지국과 단말간의 mmWave 링크가 불안정하다. 이러한 mmWave 링크 불안정성을 극복 하기 위해서, 한 mmWave 유저를 위해 다른 위치에 있는 전송 링크를 다중으로 설정하는 것이 바람직하다. 따라서, mmWave 유저는 링크 불안정성을 극복하기 위해 mmWave 다중링크 접속 성능을 가지는 것(즉, 다중 mmWave RF chain을 가짐)을 가정한다.In mmWave system, mmWave link between base station and UE is unstable due to its characteristics. To overcome this mmWave link instability, it is desirable to have multiple transmission links in different locations for one mmWave user. Thus, mmWave users assume that they have mmWave multilink connection capability (ie, having multiple mmWave RF chains) to overcome link instability.
다중 링크 전송 성능을 갖는 mmWave 단말을 지원하기 위해서는 일반적인 mmWave 기지국들(mmWave TAG 안의 기지국) 사이에서 형성되는 mmWave 다중 셀들에 대한 자원 할당을 어떻게 구성하는지가 중요하다. 왜냐하면, mmWave 단말에 mmWave 다중 링크를 통해 조인트(joint) 전송을 제공하여 다이버시티(diversity)를 확보함으로써 링크 안정성을 보장하려면, 같은 시간의 타이밍에 특정 mmWave 유저를 위해 무선 자원이 할당되어야 한다. 그런데, 만약 어떤 시간 구간에서 복수의 mmWave 셀들의 빔 방향이 한 구역을 향하여 겹치는 상황이 발생 하면, mmWave 셀들에서 전송되는 신호가 서로 큰 간섭으로 작용할 수 있다. 이로 인해 데이터 전송 성능 또는 수신 성능이 매우 열화 될 수 있다. 이를 방지하기 위해서는 각 mmWave 셀들에서 해당 mmWave 유저를 위해, mmWave 셀들 또는 mmWave 셀들의 빔 방향이 겹치지 않게 구성하는 것이 바람직하다.In order to support mmWave terminals with multi-link transmission capability, it is important to configure resource allocation for mmWave multiple cells formed between general mmWave base stations (base stations in mmWave TAG). Because, in order to ensure link stability by providing joint transmission through mmWave multiple links to mmWave terminals to ensure diversity, radio resources must be allocated for specific mmWave users at the same timing. However, if a situation occurs where a beam direction of a plurality of mmWave cells overlap in one region in a certain time period, signals transmitted from mmWave cells may act as large interference with each other. This can result in very poor data transmission or reception performance. In order to prevent this, for the corresponding mmWave user in each mmWave cells, it is preferable to configure the beam direction of the mmWave cells or mmWave cells do not overlap.
이와 같은 자원 할당 정책은 각 mmWave 셀들과 mmWave 유저들의 링크 활용 용도에 따라 달라지지만, 그러한 정책이 결정 되었을 때 그에 맞는 자원 할당 구성이 필요하다. 도 13은 각 인터 사이트 간의 셀 구성을 TDM 방식으로 설정하여 mmWave 셀 간 간섭을 줄이기 위한 예시이다.This resource allocation policy depends on the link utilization of each mmWave cell and mmWave users, but it is necessary to configure the resource allocation accordingly when such a policy is determined. FIG. 13 illustrates an example of reducing interference between mmWave cells by setting a cell configuration between each intersite in a TDM scheme.
도 13(a)를 참조하면, mmWave 단말을 위해 세 개의 기지국이 협력 전송을 수행할 수 있음을 나타낸다. 본 발명의 실시예들에서는 각 mmWave 기지국은 45도의 빔폭으로 mmWave 셀을 형성하는 것을 가정한다. 즉, 하나의 mmWave 기지국에는 8개의 mmWave 셀이 구성될 수 있다. 이와 같이 mmWave 셀들이 구성된 mmWave 기지국들은 하나의 TAG로 구성될 수 있다. Referring to FIG. 13A, three base stations may perform cooperative transmission for an mmWave terminal. In the embodiments of the present invention, it is assumed that each mmWave base station forms an mmWave cell with a beam width of 45 degrees. That is, eight mmWave cells may be configured in one mmWave base station. As such, mmWave base stations configured with mmWave cells may be configured with one TAG.
도 13(b)를 참조하면, 각 mmWave 셀들에는 TDM 방식으로 무선 자원이 할당될 수 있다. 예를 들어, mmWave 시스템의 1 TTI(Transmission Time Interval)는 1ms, 0.5ms 또는 그 이하로 설정될 수 있으나, 편의상 1ms로 가정한다. 즉, 1서브프레임이 1 TTI인 경우를 가정한다. 도 13(b)의 각 서브프레임 내의 숫자는 도 13(a)의 각 기지국에 구성되는 mmWave 셀들의 인덱스 및 서브프레임 인덱스를 의미한다.Referring to FIG. 13B, radio resources may be allocated to each mmWave cell in a TDM manner. For example, one transmission time interval (TTI) of the mmWave system may be set to 1 ms, 0.5 ms or less, but is assumed to be 1 ms for convenience. In other words, it is assumed that one subframe is one TTI. The number in each subframe of FIG. 13 (b) means the index and subframe index of mmWave cells configured in each base station of FIG. 13 (a).
도 13(a) 및 (b)를 참조하면, mmWave BS0의 mmWave 셀 2는 서브프레임 인덱스 2에서, mmWave BS1의 mmWave 셀 6은 서브프레임 인덱스 6에서, mmWave BS2의 mmWave 셀 0은 서브프레임 인덱스 0에서 각각 mmWave 단말에 무선 자원을 할당하여 데이터를 송수신할 수 있다. 즉, mmWave 단말은 단일 mmWave 링크인 경우보다 다중 mmWave 링크인 경우(예를 들어, 세 개의 mmWave 기지국들과 데이터를 송수신함으로써) 데이터 처리량이 증가될 수 있다.Referring to FIGS. 13A and 13B, mmWave cell 2 of mmWave BS0 is in subframe index 2, mmWave cell 6 of mmWave BS1 is in subframe index 6, and mmWave cell 0 in mmWave BS2 is subframe index 0 In each of the mmWave terminal can allocate radio resources to transmit and receive data. That is, the mmWave terminal may increase the data throughput in the case of multiple mmWave links (for example, by transmitting and receiving data with three mmWave base stations) than in the case of a single mmWave link.
도 13에서 도시한 mmWave 셀들의 형태 및 서브프레임 구성은 하나의 예시이며, mmWave 셀들의 개수 등은 mmWave 기지국의 성능(예를 들어, 지원 가능한 빔폭 등)에 따라 달라질 수 있다. 도 13에서 mmWave 단말은 mmWave BS0 내지 BS2와 도 8 내지 도 9 등에서 설명한 바와 같이 아날로그 빔 포밍 및 하이브리드 빔포밍 과정을 수행한 것을 가정한다.The shape and subframe configuration of the mmWave cells shown in FIG. 13 is one example, and the number of mmWave cells and the like may vary depending on the performance (eg, supportable beamwidth, etc.) of the mmWave base station. In FIG. 13, it is assumed that the mmWave terminal performs analog beamforming and hybrid beamforming processes as described in mmWave BS0 to BS2 and FIGS. 8 to 9.
도 14는 mmWave 단말에 설정 가능한 다중 mmWave 링크를 설명하기 위한 도면이다.14 is a diagram for describing multiple mmWave links that can be set in an mmWave terminal.
mmWave 전송에서 링크 안정성을 높이기 위한 방안으로 멀티 링크(Multi-link)로부터 데이터를 전송 받는 방안을 고려할 수 있다. 이러한 경우, 6GHz 이상 mmWave 대역에서는 심볼 구간(symbol duration)이 상당히 짧아 질 수 있다. 예를 들어, mmWave 시스템에서 사용되는 심볼이 기존 LTE/LTE-A 시스템에서 OFDM 심볼의 1/8 정도라고 가정하면(즉, 약 10us(1.7us(cp)+8.3us)), 이에 따라 순환 전치(CP: Cyclic Prefix) 길이 또한 짧아질 수 있다. 따라서, 인접 전송점(Transmission Point) 간에 시간 동기가 엄격히 맞는 상황인 경우에도, 전송점과 수신점 사이의 거리에 따라 발생하는 신호 지연은 다중 전송 지점으로부터 다양한 값을 갖게 되고 많은 전송 점으로부터 들어 오는 신호가 CP 범위 내에 들어 온다는 보장을 하기 어려워 진다.In order to improve link stability in mmWave transmission, a method of receiving data from a multi-link may be considered. In this case, the symbol duration may be considerably shorter in the mmWave band of 6 GHz or more. For example, assuming that the symbol used in the mmWave system is about 1/8 of the OFDM symbol in the existing LTE / LTE-A system (ie, about 10us (1.7us (cp) + 8.3us)), the cyclic prefix (CP: Cyclic Prefix) Length can also be shortened. Therefore, even in a situation where the time synchronization between the adjacent transmission points is strictly matched, the signal delay that occurs according to the distance between the transmission point and the receiving point has various values from multiple transmission points and comes from many transmission points. It becomes difficult to guarantee that the signal is within the CP range.
또한, 어느 특정 mmWave 유저를 위해 여러 기지국들이 조인트 전송(joint transmission)을 수행하기 위해서는, 특정 타이밍에 특정 단말을 위해 각 mmWave 기지국이 아날로그 빔을 지향해야 한다. 그런데, 만약 다수의 사용자가 그 셀에 있거나 또는 다른 전송 수신 패턴을 가지는 mmWave 유저가 있다면, 다수 사용자 간의 다중 접속(multiple access)까지 고려해야 한다. 따라서, 각 셀 할당 시간을 조정하는 방법은 상당한 복잡할 수 있다.In addition, in order for several base stations to perform joint transmission for a certain mmWave user, each mmWave base station must direct an analog beam for a specific terminal at a specific timing. However, if multiple users are in the cell or there are mmWave users with different transmission and reception patterns, multiple access between multiple users should be considered. Thus, the method of adjusting each cell allocation time can be quite complex.
도 15는 다른 링크 접속 패턴을 원하는 mmWave 단말이 있는 경우에 다중 링크 설정의 모호성을 설명하기 위한 도면이다.FIG. 15 is a diagram for explaining ambiguity of multi-link configuration when there is an mmWave terminal that desires another link connection pattern.
도 15를 참조하면, mmWave UE0 및 mmWave UE1은 mmWave BS0 및 mmWave BS1의 mmWave 셀 영역 내에 위치하고 있다. mmWave UE0은 mmWave BS0 및 BS1에 동시 접속을 원하는 단말이고, mmWave UE1은 mmWave BS0에 대해서만 접속을 원하는 단말인 것을 가정한다. 이때, mmWave UE0은 mmWave BS0 및 BS1과 동시 접속을 원하므로 문제가 없으나, mmWave UE1은 mmWave BS0에만 접속할 것을 원하므로 mmWave BS1로부터의 간섭을 받을 수 있다. 또한, mmWave BS1은 mmWave UE0을 위해 데이터를 전송해야할지 또는 mmWave UE1에 간섭을 주기 때문에 데이터를 전송하지 말아야 할지 모호성이 발생할 수 있다.Referring to FIG. 15, mmWave UE0 and mmWave UE1 are located in the mmWave cell region of mmWave BS0 and mmWave BS1. It is assumed that mmWave UE0 is a terminal that wants to simultaneously connect to mmWave BS0 and BS1, and mmWave UE1 is a terminal that wants to connect only to mmWave BS0. At this time, mmWave UE0 has no problem because it wants to simultaneously connect with mmWave BS0 and BS1, but mmWave UE1 may receive interference from mmWave BS1 because it wants to connect only to mmWave BS0. In addition, ambiguity may occur whether mmWave BS1 should transmit data for mmWave UE0 or not because it interferes with mmWave UE1.
따라서, 각 레가시 기지국에 mmWave 셀들이 오버레이(overlaid)된 mmWave TAG 안에서, 각 mmWave 기지국들은 mmWave 단말들의 다중 접속을 위한 자원 구성을 할 수 있다. 즉, mmWave 기지국들 안에 함께 위치한(collocated) mmWave 셀들 사이에 정해진 전송 패턴으로 mmWave 단말에 자원 할당을 함으로써(도 13 참조), 링크의 안정성이 향상될뿐만 아니라 사용자 전송율도 높일 수 있다.Accordingly, in the mmWave TAG in which mmWave cells are overlaid on each legacy base station, each mmWave base stations may configure resources for multiple access of mmWave terminals. That is, by allocating resources to the mmWave terminal with a predetermined transmission pattern between the mmWave cells colocated in the mmWave base stations (see FIG. 13), not only the link stability may be improved but also the user transmission rate may be increased.
만약, 특정 mmWave 유저를 위한 조인트 전송(예를 들어, 같은 전송 타이밍에 다른 셀이 동시에 특정 유저를 위해 빔포밍 셀 방향을 맞추는 전송)이 수행된다면, mmWave 셀간 전송 간섭을 최대한 줄일 수 있도록 다중 셀을 구성함으로써, 각 mmWave 셀이 사용자에게 지향하는 빔이 서로 다른 시간에 도달하도록 하는 것이 바람직하다.If joint transmission is performed for a particular mmWave user (e.g., transmission of other cells simultaneously orienting beamforming cells for a specific user at the same transmission timing), multiple cells may be used to minimize transmission interference between mmWave cells. By configuring, it is desirable for each mmWave cell to reach a different time beam that is directed to the user.
3.3 mmWave 자원 할당 방법3.3 mmWave Resource Allocation Method
본 발명의 실시예들에서, 다중 링크 연결 성능을 가지고 있는 mmWave 단말은 자신과 링크 연결(link connection)을 맺고 있는 각 mmWave 기지국들에 함께 위치한 mmWave 셀들의 식별자들과 각 mmWave 셀들에 대한 TA 값 및 주파수 오프셋 값을 미리 알고 있는 것을 가정한다. 또한, mmWave 단말은 각 mmWave 기지국과 동기가 맞춰져 있는 것을 가정한다.In the embodiments of the present invention, an mmWave terminal having a multi-link connection capability may include identifiers of mmWave cells co-located with each mmWave base station having a link connection and TA values for each mmWave cells. It is assumed that the frequency offset value is known in advance. In addition, it is assumed that the mmWave terminal is synchronized with each mmWave base station.
도 16은 mmWave 기지국에 다중 링크 연결을 위한 다중 mmWave 셀을 구성하는 방법을 설명하기 위한 도면이다.FIG. 16 is a diagram illustrating a method of configuring multiple mmWave cells for multiple link connection to an mmWave base station.
도 16의 기본 설정은 도 13과 동일하다. 다만, mmWave 기지국들의 배치 형태만 다르다. 도 16(a)를 참조하면, mmWave BS0의 mmWave 셀 6은 서브프레임 인덱스 6에서, mmWave BS1의 mmWave 셀 2는 서브프레임 인덱스 2에서, mmWave BS2의 mmWave 셀 0은 서브프레임 인덱스 0에서 각각 mmWave 단말에 무선 자원을 할당하여 데이터를 송수신할 수 있다.The basic setting of FIG. 16 is the same as that of FIG. However, only the deployment form of mmWave base stations is different. Referring to FIG. 16 (a), mmWave cell 6 of mmWave BS0 is in subframe index 6, mmWave cell 2 of mmWave BS1 is in subframe index 2, and mmWave cell 0 in mmWave BS2 is mmWave terminal in subframe index 0, respectively. Radio resources can be allocated to transmit and receive data.
이때, mmWave BS2의 mmWave 셀0에는 다수의 mmWave 단말들이 존재하는 것을 가정한다. 다수의 mmWave 단말들에 데이터를 전송하기 위해, mmWave BS2는 mmWave 셀 0에 대해서는 다른 mmWave 셀 1 내지 7보다 많은 무선 자원을 할당할 수 있다. 도 16(b)를 참조하면, mmWave BS1에서 mmWave 셀2에 할당한 무선 자원과 mmWave BS2에서 mmWave 셀0에 할당한 무선 자원의 시간 구간이 겹칠 수 있다. 이러한 경우에 mmWave 단말에 mmWave 셀 간 간섭이 발생할 수 있다. 따라서, mmWave BS1은 도 16(c)와 같이 mmWave 셀2에 할당되는 무선 자원인 서브프레임2의 위치를 서브프레임4와 바꿈으로써 간섭을 회피할 수 있다. 즉, mmWave BS1은 mmWave 셀 타이밍을 수정함으로써 셀 내 간섭을 회피하는 자원 구성을 설정할 수 있다.In this case, it is assumed that a plurality of mmWave terminals exist in mmWave cell 0 of mmWave BS2. To transmit data to multiple mmWave terminals, mmWave BS2 may allocate more radio resources for mmWave cell 0 than other mmWave cells 1-7. Referring to FIG. 16B, time intervals of radio resources allocated to mmWave cell 2 in mmWave BS1 and radio resources allocated to mmWave cell 0 in mmWave BS2 may overlap. In this case, interference between mmWave cells may occur in the mmWave terminal. Therefore, mmWave BS1 can avoid interference by changing the position of subframe 2, which is a radio resource allocated to mmWave cell 2, to subframe 4 as shown in FIG. 16 (c). That is, mmWave BS1 can set a resource configuration that avoids intra-cell interference by modifying mmWave cell timing.
도 16(c)와 같은 동작을 수행하기 위해서는 각 mmWave 기지국들은 자신의 mmWave 셀들에 분포하는 mmWave 단말들의 개수 또는 밀도를 실시간으로 측정하고 있어야하며, 다른 mmWave 기지국의 mmWave 셀들에 분포하는 mmWave 단말들의 개수 또는 밀도를 알고 있는 것이 바람직하다. 이를 통해, 각 mmWave 기지국들은 mmWave 셀들에 대한 자원을 구성할 수 있다.In order to perform the operation as shown in FIG. 16 (c), each mmWave base station should measure the number or density of mmWave terminals distributed in its mmWave cells in real time, and the number of mmWave terminals distributed in mmWave cells of another mmWave base station. Or it is desirable to know the density. Through this, each mmWave base stations can configure resources for mmWave cells.
도 17은 mmWave 다중 셀 자원을 할당하는 방법 중 하나를 설명하기 위한 도면이다.FIG. 17 illustrates one method of allocating mmWave multi-cell resources.
도 17은 도 16에서 설명한 셀 구성을 기반으로 수행되되, mmWave BS1에서 mmWave 셀들에 대한 무선 자원을 구성하는 방법에 관한 것이다. mmWave BS1 또는 mmWave BS0 내지 BS2는 하나의 TAG를 구성하는 것을 가정한다.FIG. 17 is performed based on the cell configuration described in FIG. 16 and relates to a method of configuring radio resources for mmWave cells in mmWave BS1. It is assumed that mmWave BS1 or mmWave BS0 to BS2 constitute one TAG.
mmWave 시스템 내에서 mmWave 단말의 이동성을 관리하는 개체인 mmWave MME 또는 mmWave TAG를 관리하는 mmWave 마스터 BS는 TAG 내의 모든 mmWave 셀들 내에 분포하는 mmWave 단말들의 개수 또는 밀도를 실시간, 주기적 또는 요청이 있는 경우에 측정한다. 이후, mmWave MME 또는 mmWave 마스터 BS는 각 mmWave 셀에 대한 자원 할당 구성을 수행할 수 있다. mmWave 마스터 BS는 TAG 내의 임의의 mmWave BS로 설정되거나, mmWave 시스템 상에서 구비된 TAG를 관리하기 위한 상위 개체일 수 있다 (S1710).The mmWave master BS, which manages the mmWave MME or mmWave TAG, an entity that manages the mobility of mmWave terminals in the mmWave system, measures the number or density of mmWave terminals distributed in all mmWave cells in the TAG in real time, periodically, or on demand. do. Thereafter, the mmWave MME or mmWave master BS may perform resource allocation configuration for each mmWave cell. The mmWave master BS may be set to any mmWave BS in the TAG or may be a higher entity for managing a TAG provided on the mmWave system (S1710).
S1710 단계에서, mmWave MME 또는 mmWave 마스터 BS는 자원 할당 구성 정보를 해당 TAG 내의 모든 mmWave BS들에게 백홀망을 통해 전송할 수 있다. 자원 할당 구성 정보에는 도 13(b) 또는 도 16(b)와 같은 형태의 자원 할당 구성에 대한 정보가 포함될 수 있다.In step S1710, mmWave MME or mmWave master BS may transmit the resource allocation configuration information to all mmWave BSs in the TAG over the backhaul network. The resource allocation configuration information may include information about the resource allocation configuration in the form shown in FIG. 13 (b) or 16 (b).
mmWave MME 또는 mmWave 마스터 BS는 자원 할당 구성 정보를 기반으로 다중 셀 간 간섭을 파악할 수 있다. 다중 셀 간 간섭은 mmWave 셀들 간의 간섭 또는 특정 mmWave 단말에 대한 간섭일 수 있다. 이때, mmWave 단말들의 이동으로 인하 mmWave 셀 내의 mmWave 단말의 분포가 달라질 수 있다. 이로 인해, mmWave 기지국이 mmWave 셀에 할당하는 자원 구성이 변경될 수 있다 (S1720).The mmWave MME or mmWave master BS can identify the interference between multiple cells based on the resource allocation configuration information. Inter-cell interference may be interference between mmWave cells or interference for a particular mmWave terminal. In this case, the distribution of mmWave terminals in the mmWave cell may be changed due to the movement of mmWave terminals. For this reason, the resource configuration allocated to the mmWave cell by the mmWave base station may be changed (S1720).
S1720 단계에서, 자원 할당 구성 정보를 기반으로 중첩 셀이 발생하지 않으면, mmWave MME 또는 mmWave 마스터 BS는 다중 셀에 대한 자원 할당 구성 정보를 포함하는 자원 할당 구성 메시지를 각 mmWave TAG 내의 mmWave BS들에게 전송한다 (S1740).In step S1720, if the overlapping cell does not occur based on the resource allocation configuration information, the mmWave MME or mmWave master BS transmits a resource allocation configuration message including resource allocation configuration information for multiple cells to mmWave BSs in each mmWave TAG. (S1740).
S1720 단계에서, 자원 할당 구성 정보를 기반으로 mmWave 셀들간 시간 영역에서 중첩되는 셀이 발생하면, mmWave MME 또는 mmWave 마스터 BS는 셀 내 간섭을 고려하여 다중 셀에 대한 자원 할당 구성 정보를 수정한다 (S1730).In step S1720, when a cell overlapping in the time domain between mmWave cells occurs based on resource allocation configuration information, mmWave MME or mmWave master BS modifies resource allocation configuration information for multiple cells in consideration of interference in the cell (S1730). ).
이후, mmWave MME 또는 mmWave 마스터 BS는 수정된 자원 할당 구성 정보를 포함하는 자원 할당 구성 메시지를 각 mmWave TAG 내의 mmWave BS들에게 전송한다 (S1740).Thereafter, the mmWave MME or mmWave master BS transmits a resource allocation configuration message including the modified resource allocation configuration information to the mmWave BSs in each mmWave TAG (S1740).
자원 할당 구성 메시지에는 각 mmWave BS들의 식별자 및 각 mmWave BS들에 구성된 mmWave 셀들에 대한 자원 할당 정보가 포함될 수 있다. 만약, TAG 내에 mmWave 단말 분포의 변화 또는 mmWave 셀에 대한 자원 할당 등의 변화로 인해 자원 할당 구성이 변경되는 경우에는, 변경된 mmWave 셀 전송 순서가 있는 mmWave 기지국의 식별자 정보(예를 들어, mmWave BS1의 식별자), 변경된 mmWave 셀 인덱스(예를 들어, mmWave 셀 인덱스 2 및 4) 및 수정된 mmWave 셀 유지 시간 정보가 더 포함될 수 있다.The resource allocation configuration message may include an identifier of each mmWave BSs and resource allocation information for mmWave cells configured in each mmWave BSs. If the resource allocation configuration is changed due to a change in the distribution of mmWave terminals in the TAG or a resource allocation for the mmWave cell, the identifier information of the mmWave base station with the changed mmWave cell transmission order (for example, in mmWave BS1). Identifiers), modified mmWave cell indexes (eg, mmWave cell indexes 2 and 4) and modified mmWave cell retention time information.
3.4 링크 불안정성을 고려한 자원 할당 방법3.4 Resource Allocation Method Considering Link Instability
이하에서는 다중 mmWave 링크가 NLoS에서 LoS 또는 LoS에서 NLoS로 천이시 링크 불안정성이 증가하는 상황에서 자원을 할당하는 방법들에 대해서 설명한다.Hereinafter, methods for allocating resources in a situation where link instability increases when a multi-mmWave link transitions from NLoS to LoS or LoS to NLoS will be described.
도 18은 다중 mmWave 링크 환경에서 링크 불안정성을 줄이기 위한 자원 할당 방법을 설명하기 위한 도면이다.18 is a diagram illustrating a resource allocation method for reducing link instability in a multi-mmWave link environment.
도 18에서 각 mmWave BS들은 백홀망으로서 Xn 인터페이스를 통해 서로 연결되어 있고, MME가 각 mmWave BS들과 백홀망으로 연결되어 있는 것을 가정한다. 또한, 도 18의 자원 할당 구성은 기본적으로 도 17과 같은 방식으로 도 16(b)에서 설명한 형태와 같이 구성되어 있는 것을 가정한다.In FIG. 18, it is assumed that each mmWave BS is connected to each other through an Xn interface as a backhaul network, and that an MME is connected to each mmWave BS with a backhaul network. In addition, it is assumed that the resource allocation configuration of FIG. 18 is basically configured as shown in FIG. 16B in the same manner as in FIG. 17.
도 18(a)는 mmWave 셀 내의 mmWave 유저 분포에 따른 다중 mmWave 셀의 설정 방식과 타겟 링크 안정성이 열화된 상태를 도시한다. 예를 들어, mmWave BS2의 mmWave 셀 0에는 다수의 mmWave 유저가 분포하고 있다. 이때, 타겟 mmWave 단말의 mmWave 링크가 LoS에서 NLoS로 천이가 발생하여 링크 불안정성이 크게 증가할 수 있다. 또한, mmWave BS1의 mmWave 셀2와 mmWave BS2의 mmWave 셀0가 동일 시간에 신호를 전송하므로, 타겟 mmWave 단말에 셀 내 간섭이 발생할 수 있다.FIG. 18A illustrates a state in which multiple mmWave cells are set and target link stability is deteriorated according to mmWave user distribution in the mmWave cell. For example, a large number of mmWave users are distributed in mmWave cell 0 of mmWave BS2. At this time, the mmWave link of the target mmWave terminal transitions from LoS to NLoS can greatly increase the link instability. In addition, since mmWave cell 2 of mmWave BS1 and mmWave cell 0 of mmWave BS2 transmit signals at the same time, inter-cell interference may occur in the target mmWave terminal.
도 18(b)를 참조하면, mmWave BS2는 MME 및 mmWave BS1에 SN(Sequence Number) 상태 전달 메시지를 백홀망을 통해 전송할 수 있다. 이때, SN 상태 전달 메시지는 mmWave BS2에서 전송을 하지 못한 패킷의 번호 또는 송수신할 패킷의 번호를 알려주기 위해 전송된다. 또한, MME는 mmWave BS1의 셀 인덱스 2와 4의 위치를 변경함으로써 mmWave BS2로부터 발생하는 셀 내 간섭을 피할 수 있다.Referring to FIG. 18B, the mmWave BS2 may transmit a Sequence Number (SN) status transfer message to the MME and mmWave BS1 through the backhaul network. At this time, the SN status transfer message is transmitted to inform the number of packets not transmitted or the number of packets to be transmitted and received in mmWave BS2. In addition, the MME can avoid intra-cell interference resulting from mmWave BS2 by changing the positions of cell indexes 2 and 4 of mmWave BS1.
도 18(c)를 참조하면, mmWave BS1은 mmWave BS2로부터 SN 상태 전달 메시지를 수신함으로써, 타겟 mmWave 단말에 전송할 다음 패킷이 어떤 것인지 알 수 있다. 따라서, mmWave BS1은 변경된 셀 인덱스 2가 지시하는 mmWave 셀 2 및 서브프레임 2를 통해 데이터 패킷을 계속 전송할 수 있다.Referring to FIG. 18C, the mmWave BS1 may receive an SN status transfer message from the mmWave BS2, so that the next packet to be transmitted to the target mmWave terminal may be known. Accordingly, mmWave BS1 may continue to transmit data packets on mmWave cell 2 and subframe 2 indicated by modified cell index 2. FIG.
만약에 가정과 같이 TAG의 mmWave 기지국들이 레가시 MME 또는 mmWave MME와 백홀망을 통해 연결되어 있고, 타겟 mmWave 단말이 다중 mmWave 링크 연결 성능을 가지고 있을 수 있다. 이러한 경우, 타겟 mmWave 단말이 mmWave 셀과 연결된 타겟 mmWave 링크가 도 18(a)와 같이 불안정 해진다면, mmWave BS2는 다음 mmWave BS(예를 들어, mmWave BS1) 또는 MME에 SN 상태 전달 메시지를 전송하여, 다음 mmWave 링크에서 SN 상태 전달 메시지가 지시하는 데이터 패킷을 전송한다. 이때, SN 상태 전달 메시지에는 데이터를 전송할 대상인 타겟 mmWave 단말을 지시하는 임시 단말 식별자(Temp UE ID)가 포함될 수 있다.If it is assumed that the mmWave base stations of the TAG is connected to the legacy MME or mmWave MME through the backhaul network, the target mmWave terminal may have multiple mmWave link connection capability. In this case, if the target mmWave terminal is unstable as the target mmWave link connected to the mmWave cell as shown in Figure 18 (a), mmWave BS2 transmits an SN status transfer message to the next mmWave BS (for example, mmWave BS1) or MME Next, transmit the data packet indicated by the SN status transfer message on the next mmWave link. In this case, the SN status transfer message may include a temporary UE ID indicating a target mmWave terminal to which data is to be transmitted.
도 19는 다중 mmWave 링크 환경에서 링크 불안정성을 줄이기 위한 자원 할당 방법을 설명하기 위한 다른 도면이다.19 is another diagram for explaining a resource allocation method for reducing link instability in a multi-mmWave link environment.
도 19는 도 18에서 설명한 내용을 MME 및 mmWave 마스터 BS 관점에서 설명한다. mmWave 시스템 내에서 mmWave 단말의 이동성을 관리하는 개체인 mmWave MME 또는 mmWave TAG를 관리하는 mmWave 마스터 BS는 TAG 내의 모든 mmWave 셀들 내에 분포하는 mmWave 단말들의 개수 또는 밀도를 실시간, 주기적 또는 요청이 있는 경우에 측정한다. 이후, mmWave MME 또는 mmWave 마스터 BS는 각 mmWave 셀에 대한 자원 할당 구성을 수행할 수 있다. mmWave 마스터 BS는 TAG 내의 임의의 mmWave BS로 설정되거나, mmWave 시스템 상에서 구비된 TAG를 관리하기 위한 상위 개체일 수 있다 (S1910).FIG. 19 describes the contents described with reference to FIG. 18 in terms of MME and mmWave master BS. The mmWave master BS, which manages the mmWave MME or mmWave TAG, an entity that manages the mobility of mmWave terminals in the mmWave system, measures the number or density of mmWave terminals distributed in all mmWave cells in the TAG in real time, periodically, or on demand. do. Thereafter, the mmWave MME or mmWave master BS may perform resource allocation configuration for each mmWave cell. The mmWave master BS may be set to any mmWave BS in the TAG or may be a higher entity for managing the TAG provided on the mmWave system (S1910).
S1910 단계에서, mmWave MME 또는 mmWave 마스터 BS는 자원 할당 구성 정보를 해당 TAG 내의 모든 mmWave BS들에게 백홀망을 통해 전송할 수 있다. 자원 할당 구성 정보에는 도 13(b), 도 16(b) 또는 도 18(a)와 같은 형태의 자원 할당 구성에 대한 정보가 포함될 수 있다.In step S1910, mmWave MME or mmWave master BS may transmit the resource allocation configuration information to all mmWave BSs in the TAG over the backhaul network. The resource allocation configuration information may include information on the resource allocation configuration in the form of FIG. 13 (b), FIG. 16 (b), or FIG. 18 (a).
mmWave TAG에 포함된 mmWave 기지국들은 함께 구성된 mmWave 셀들의 링크 안정성을 각각 측정한다. 예를 들어, 도 18(b)에서는 mmWave BS2가 mmWave 셀0에 대한 링크 안정성을 측정하여 LoS/NLoS 천이가 발생한 것을 확인하였다 (S1920).The mmWave base stations included in the mmWave TAG each measure the link stability of the mmWave cells configured together. For example, in FIG. 18 (b), mmWave BS2 measures link stability for mmWave cell 0 to confirm that LoS / NLoS transition has occurred (S1920).
S1920 단계에서 mmWave 링크가 불안정한 것으로 판단하면, 해당 mmWave 링크를 관리하는 mmWave 기지국에서 SN 전달 메시지를 MME 또는 TAG의 다른 mmWave BS들에게 전송할 수 있다. 예를 들어, mmWave BS2가 mmWave 셀0에서 전송하지 못한 데이터 패킷에 대한 SN을 지시하는 SN 상태 전달 메시지를 MME 또는 다른 mmWave BS들로 전송할 수 있다 (S1930).If it is determined in step S1920 that the mmWave link is unstable, the mmWave base station managing the mmWave link may transmit the SN transfer message to other mmWave BSs of the MME or TAG. For example, mmWave BS2 may transmit an SN status transfer message indicating an SN for a data packet not transmitted by mmWave cell 0 to MME or other mmWave BSs (S1930).
S1930 단계에서, MME가 SN 상태 전달 메시지를 수신하면, 타겟 mmWave 단말에 자원 할당 구성 정보를 기반으로 가장 빠른 시간에 mmWave 링크가 연결되는 mmWave 셀의 기지국 또는 TAG 내의 모든 mmWave 기지국으로 SN 상태 전달 메시지를 전송할 수 있다. 예를 들어, MME는 mmWave BS1로 SN 상태 전달 메시지를 전송할 수 있다. 이러한 경우, mmWave BS1에서 타겟 mmWave 단말과 mmWave 링크가 연결되는 시점(즉, 변경된 서브프레임2)에서 데이터를 이어서 전송할 수 있다 (S1940).In step S1930, when the MME receives the SN status forwarding message, the SN status forwarding message is transmitted to the base station of the mmWave cell to which the mmWave link is connected or all the mmWave base stations in the TAG at the earliest time based on the resource allocation configuration information. Can transmit For example, the MME may send an SN status transfer message to mmWave BS1. In this case, data may be subsequently transmitted at a time point when the target mmWave terminal and the mmWave link are connected in the mmWave BS1 (that is, the changed subframe 2) (S1940).
또는, S1930 단계에서 mmWave BS2는 TAG 내에 속한 모든 mmWave 기지국들로 SN 상태 전송 메지시를 전송할 수 있다. 이러한 경우에는 SN 상태 전달 메시지를 수신한 mmWave 기지국들이 S1940 단계에서 타겟 mmWave 단말에게 SN이 지시하는 데이터 패킷을 전송할 수 있다.Or, in step S1930 mmWave BS2 may transmit the SN status transmission message to all mmWave base stations belonging to the TAG. In this case, the mmWave base stations receiving the SN status transfer message may transmit a data packet indicated by the SN to the target mmWave terminal in step S1940.
상술한 본 발명의 실시예들은 mmWave TAG 안의 mmWave 기지국들에 함께 위치한(collocated) mmWave 셀들이 밀집한 밀도로 배치 되었을 경우에도 적용될 수 있다. 이때, 본 발명의 실시예들은 mmWave 셀들 내의 mmWave 단말의 분포를 고려하여 무선 자원을 할당함으로써 mmWave 셀 설정시에 셀 내 간섭을 줄일 수 있다. 또한 mmWave 링크의 불안정성을 고려하여, 다중 링크 자원을 할당할 수 있다.The above-described embodiments of the present invention can be applied even when mmWave cells collocated with mmWave base stations in the mmWave TAG are arranged at a dense density. At this time, embodiments of the present invention can reduce the intra-cell interference when configuring the mmWave cell by allocating radio resources in consideration of the distribution of mmWave terminals in the mmWave cells. In addition, considering the instability of the mmWave link, it is possible to allocate multiple link resources.
본 발명의 실시예들을 통해 다중 mmWave 링크 환경에서도 셀간 간섭을 낮출 수 있으며, 시간/주파수 동기를 쉽게 맞출 수 있다. 왜냐하면 mmWave 단말 및 mmWave 기지국들이 특정 타이밍에 특정 셀 연결을 위한 TA와 주파수 오프셋을 미리 알고 있기 때문이다. 또한, 다중 mmWave 링크 환경에서 효율적으로 자원을 할당함으로써, 각 mmWave 단말에 대한 전송률이 향상될 수 있다. 예를 들어, 단일 mmWave 링크 환경의 경우 8번의 전송 기회에서 1번만 데이터가 송수신될 수 있으나, 도 16(c)와 같은 경우 8번의 전송 기회 동안 데이터가 3번 송수신되므로, mmWave 단말에 대한 데이터 처리량이 3배 정도 향상될 수 있다. 또한, 링크 안정성이 강화되는 장점이 있다.Through the embodiments of the present invention, inter-cell interference can be reduced even in a multi-mmWave link environment, and time / frequency synchronization can be easily adjusted. This is because the mmWave terminal and the mmWave base stations already know the TA and frequency offset for the specific cell connection at a specific timing. In addition, by efficiently allocating resources in a multi-mmWave link environment, a transmission rate for each mmWave terminal may be improved. For example, in the case of a single mmWave link environment, data may be transmitted and received only once in eight transmission opportunities. However, in the case of FIG. 16 (c), data is transmitted and received three times during eight transmission opportunities. This can be improved by three times. In addition, there is an advantage that the link stability is enhanced.
4. 구현 장치4. Implement device
도 20에서 설명하는 장치는 도 1 내지 도 19에서 설명한 방법들이 구현될 수 있는 수단이다.The apparatus described in FIG. 20 is a means by which the methods described in FIGS. 1 to 19 may be implemented.
단말(UE: User Equipment)은 상향링크에서는 송신기로 동작하고, 하향링크에서는 수신기로 동작할 수 있다. 또한, 기지국(eNB: e-Node B)은 상향링크에서는 수신기로 동작하고, 하향링크에서는 송신기로 동작할 수 있다.A user equipment (UE) may operate as a transmitter in uplink and a receiver in downlink. In addition, an e-Node B (eNB) may operate as a receiver in uplink and as a transmitter in downlink.
즉, 단말 및 기지국은 정보, 데이터 및/또는 메시지의 전송 및 수신을 제어하기 위해 각각 송신기(Transmitter: 2040, 2050) 및 수신기(Receiver: 2050, 2070)를 포함할 수 있으며, 정보, 데이터 및/또는 메시지를 송수신하기 위한 안테나(2000, 2010) 등을 포함할 수 있다. That is, the terminal and the base station may include transmitters 2040 and 2050 and receivers 2050 and 2070 to control the transmission and reception of information, data and / or messages, respectively. Or antennas 2000 and 2010 for transmitting and receiving messages.
또한, 단말 및 기지국은 각각 상술한 본 발명의 실시예들을 수행하기 위한 프로세서(Processor: 2020, 2030)와 프로세서의 처리 과정을 임시적으로 또는 지속적으로 저장할 수 있는 메모리(2080, 2090)를 각각 포함할 수 있다.In addition, the terminal and the base station may each include a processor 2020 and 2030 for performing the above-described embodiments of the present invention and a memory 2080 and 2090 for temporarily or continuously storing the processing of the processor. Can be.
상술한 단말 및 기지국 장치의 구성성분 및 기능들을 이용하여 본원 발명의 실시예들이 수행될 수 있다. 단말은 mmWave 단말이며, 단말의 프로세서는 송신기 및 수신기를 제어하여 mmWave 빔포밍(예를 들어, 아날로그, 하이브리드 빔포밍 등)을 수행할 수 있다. 또한, mmWave 단말은 하향링크 데이터 채널을 측정하여 링크 식별 정보를 구성 및 mmWave 기지국에 피드백할 수 있다. mmWave 기지국은 수신한 피드백 정보를 기반으로 mmWave 단말에 대한 자원을 할당하고 자원 할당 정보를 mmWave 단말 및/또는 다른 mmWave 기지국에 전송할 수 있다. 상세한 내용은 제1절 내지 제3절에서 설명한 내용을 참조할 수 있다.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. In addition, 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 and transmit the resource allocation information to the mmWave terminal and / or another mmWave base station. For details, refer to the contents described in Sections 1 to 3.
단말 및 기지국에 포함된 송신기 및 수신기는 데이터 전송을 위한 패킷 변복조 기능, 고속 패킷 채널 코딩 기능, 직교주파수분할다중접속(OFDMA: Orthogonal Frequency Division Multiple Access) 패킷 스케줄링, 시분할듀플렉스(TDD: Time Division Duplex) 패킷 스케줄링 및/또는 채널 다중화 기능을 수행할 수 있다. 또한, 도 20의 단말 및 기지국은 저전력 RF(Radio Frequency)/IF(Intermediate Frequency) 모듈을 더 포함할 수 있다.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. In addition, the terminal and the base station of FIG. 20 may further include a low power radio frequency (RF) / intermediate frequency (IF) module.
한편, 본 발명에서 단말로 개인휴대단말기(PDA: Personal Digital Assistant), 셀룰러폰, 개인통신서비스(PCS: Personal Communication Service) 폰, GSM(Global System for Mobile) 폰, WCDMA(Wideband CDMA) 폰, MBS(Mobile Broadband System) 폰, 핸드헬드 PC(Hand-Held PC), 노트북 PC, 스마트(Smart) 폰 또는 멀티모드 멀티밴드(MM-MB: Multi Mode-Multi Band) 단말기 등이 이용될 수 있다.Meanwhile, in the present invention, 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. A Mobile Broadband System phone, a hand-held PC, a notebook PC, a smart phone, or a Multi Mode-Multi Band (MM-MB) terminal may be used.
여기서, 스마트 폰이란 이동통신 단말기와 개인 휴대 단말기의 장점을 혼합한 단말기로서, 이동통신 단말기에 개인 휴대 단말기의 기능인 일정 관리, 팩스 송수신 및 인터넷 접속 등의 데이터 통신 기능을 통합한 단말기를 의미할 수 있다. 또한, 멀티모드 멀티밴드 단말기란 멀티 모뎀칩을 내장하여 휴대 인터넷시스템 및 다른 이동통신 시스템(예를 들어, CDMA(Code Division Multiple Access) 2000 시스템, WCDMA(Wideband CDMA) 시스템 등)에서 모두 작동할 수 있는 단말기를 말한다.Here, 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. have. In addition, 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.
본 발명의 실시예들은 다양한 수단을 통해 구현될 수 있다. 예를 들어, 본 발명의 실시예들은 하드웨어, 펌웨어(firmware), 소프트웨어 또는 그것들의 결합 등에 의해 구현될 수 있다.Embodiments of the invention may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.
하드웨어에 의한 구현의 경우, 본 발명의 실시예들에 따른 방법은 하나 또는 그 이상의 ASICs(application specific integrated circuits), DSPs(digital signal processors), DSPDs(digital signal processing devices), PLDs(programmable logic devices), FPGAs(field programmable gate arrays), 프로세서, 콘트롤러, 마이크로 콘트롤러, 마이크로 프로세서 등에 의해 구현될 수 있다.In the case of a hardware implementation, 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.
펌웨어나 소프트웨어에 의한 구현의 경우, 본 발명의 실시예들에 따른 방법은 이상에서 설명된 기능 또는 동작들을 수행하는 모듈, 절차 또는 함수 등의 형태로 구현될 수 있다. 예를 들어, 소프트웨어 코드는 메모리 유닛(2080, 2090)에 저장되어 프로세서(2020, 2030)에 의해 구동될 수 있다. 상기 메모리 유닛은 상기 프로세서 내부 또는 외부에 위치할 수 있으며, 이미 공지된 다양한 수단에 의해 상기 프로세서와 데이터를 주고 받을 수 있다.In the case of an implementation by firmware or software, 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. For example, software code may be stored in the memory units 2080 and 2090 and driven by the processors 2020 and 2030. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.
본 발명은 본 발명의 정신 및 필수적 특징을 벗어나지 않는 범위에서 다른 특정한 형태로 구체화될 수 있다. 따라서, 상기의 상세한 설명은 모든 면에서 제한적으로 해석되어서는 아니되고 예시적인 것으로 고려되어야 한다. 본 발명의 범위는 첨부된 청구항의 합리적 해석에 의해 결정되어야 하고, 본 발명의 등가적 범위 내에서의 모든 변경은 본 발명의 범위에 포함된다. 또한, 특허청구범위에서 명시적인 인용 관계가 있지 않은 청구항들을 결합하여 실시예를 구성하거나 출원 후의 보정에 의해 새로운 청구항으로 포함할 수 있다.The invention can be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention. In addition, the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship or may be incorporated as new claims by post-application correction.
본 발명의 실시예들은 다양한 무선접속 시스템에 적용될 수 있다. 다양한 무선접속 시스템들의 일례로서, 3GPP(3rd Generation Partnership Project), 3GPP2 및/또는 IEEE 802.xx (Institute of Electrical and Electronic Engineers 802) 시스템 등이 있다. 본 발명의 실시예들은 상기 다양한 무선접속 시스템뿐 아니라, 상기 다양한 무선접속 시스템을 응용한 모든 기술 분야에 적용될 수 있다.Embodiments of the present invention can be applied to various wireless access systems. Examples of 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.

Claims (10)

  1. 밀리미터웨이브(mmWave)를 지원하는 무선접속 시스템에서 mmWave 기지국이 자원을 할당하는 방법에 있어서,In a method for allocating resources by the mmWave base station in a wireless access system supporting millimeter wave (mmWave),
    둘 이상의 mmWave 기지국이 포함된 TAG(Tracking Area Group) 내에 구성되는 모든 mmWave 셀들 내에 존재하는 mmWave 단말들에 대한 분포를 측정하는 단계;Measuring a distribution for mmWave terminals present in all mmWave cells configured in a Tracking Area Group (TAG) that includes two or more mmWave base stations;
    상기 측정한 mmWave 단말들에 대한 분포를 기반으로 다중 mmWave 링크에 대한 자원 할당 구성 정보를 생성하는 단계; 및Generating resource allocation configuration information for multiple mmWave links based on the measured distribution of mmWave terminals; And
    상기 자원 할당 구성 정보를 포함하는 할당 구성 메시지를 상기 TAG 내에 포함된 모든 mmWave 기지국들에 전송하는 단계를 포함하는, 자원할당방법.And transmitting an allocation configuration message including the resource allocation configuration information to all mmWave base stations included in the TAG.
  2. 제1항에 있어서,The method of claim 1,
    상기 자원 할당 구성 메시지에는 상기 TAG 내에 속한 mmWave 기지국들의 식별자 및 각 mmWave 기지국들에 구성된 mmWave 셀들에 할당된 자원을 나타내는 상기 자원 할당 구성 정보가 포함되는, 자원할당방법.The resource allocation configuration message includes an identifier of mmWave base stations belonging to the TAG and the resource allocation configuration information indicating a resource allocated to mmWave cells configured in each mmWave base stations.
  3. 제1항에 있어서,The method of claim 1,
    상기 TAG 내에 포함된 mmWave 기지국들은 각각의 성능에 따라 둘 이상의 mmWave 셀을 가지고 있고,The mmWave base stations included in the TAG have two or more mmWave cells according to their respective capabilities.
    상기 둘 이상의 mmWave 셀들은 서로 다른 무선 자원을 시간분할다중(TDM) 방식으로 할당받는, 자원할당방법.The two or more mmWave cells are allocated different radio resources in a time division multiplex (TDM) manner.
  4. 제1항에 있어서,The method of claim 1,
    상기 자원 할당 구성 정보를 기반으로 상기 TAG 내의 다중 mmWave 셀간 간섭을 측정하는 단계; 및Measuring interference between multiple mmWave cells in the TAG based on the resource allocation configuration information; And
    다중 mmWave 셀간 간섭이 발생하면, 상기 다중 mmWave 셀간 간섭을 고려하여 수정된 자원 할당 구성 정보를 상기 TAG 내의 모든 mmWave 기지국들로 전송하는 단계를 더 포함하는, 자원할당방법.And if multiple mmWave inter-cell interference occurs, transmitting the modified resource allocation configuration information to all mmWave base stations in the TAG, taking into account the inter-mmWave inter-cell interference.
  5. 제4항에 있어서,The method of claim 4, wherein
    상기 수정된 자원 할당 구성 정보는 상기 자원 할당 구성 정보가 변경된 mmWave 기지국의 식별자, 변경된 mmWave 셀 인덱스 및 수정된 mmWave 셀 유지 시간 정보가 포함되는, 자원할당방법.The modified resource allocation configuration information includes an identifier of an mmWave base station in which the resource allocation configuration information has been changed, a changed mmWave cell index, and a modified mmWave cell holding time information.
  6. 밀리미터웨이브(mmWave)를 지원하는 무선접속 시스템에서 자원을 할당하는 장치는,A device for allocating resources in a wireless access system supporting millimeter wave (mmWave),
    송신기;transmitter;
    수신기; 및receiving set; And
    프로세서를 포함하되,Include processors,
    상기 프로세서는: The processor is:
    상기 송신기 및 상기 수신기를 제어하여 둘 이상의 mmWave 기지국이 포함된 TAG(Tracking Area Group) 내에 구성되는 모든 mmWave 셀들 내에 존재하는 mmWave 단말들에 대한 분포를 측정하고;Controlling the transmitter and the receiver to measure a distribution for mmWave terminals present in all mmWave cells configured in a TAG (Tracking Area Group) including two or more mmWave base stations;
    상기 측정한 mmWave 단말들에 대한 분포를 기반으로 다중 mmWave 링크에 대한 자원 할당 구성 정보를 생성하고;Generating resource allocation configuration information for multiple mmWave links based on the measured distribution of mmWave terminals;
    상기 송신기를 제어하여 상기 자원 할당 구성 정보를 포함하는 할당 구성 메시지를 상기 TAG 내에 포함된 모든 mmWave 기지국들에 전송하도록 구성되는, 장치.And control the transmitter to send an allocation configuration message including the resource allocation configuration information to all mmWave base stations included in the TAG.
  7. 제6항에 있어서,The method of claim 6,
    상기 자원 할당 구성 메시지에는 상기 TAG 내에 속한 mmWave 기지국들의 식별자 및 각 mmWave 기지국들에 구성된 mmWave 셀들에 할당된 자원을 나타내는 상기 자원 할당 구성 정보가 포함되는, 장치.And the resource allocation configuration message includes an identifier of mmWave base stations belonging to the TAG and the resource allocation configuration information indicating a resource allocated to mmWave cells configured in each mmWave base stations.
  8. 제6항에 있어서,The method of claim 6,
    상기 TAG 내에 포함된 mmWave 기지국들은 각각의 성능에 따라 둘 이상의 mmWave 셀을 가지고 있고,The mmWave base stations included in the TAG have two or more mmWave cells according to their respective capabilities.
    상기 둘 이상의 mmWave 셀들은 서로 다른 무선 자원을 시간분할다중(TDM) 방식으로 할당받는, 장치.Wherein the two or more mmWave cells are allocated different radio resources in a time division multiplex (TDM) manner.
  9. 제6항에 있어서,The method of claim 6,
    상기 프로세서는:The processor is:
    상기 자원 할당 구성 정보를 기반으로 상기 TAG 내의 다중 mmWave 셀간 간섭을 상기 수신기를 제어하여 측정하고;Controlling the receiver to measure the interference between multiple mmWave cells in the TAG based on the resource allocation configuration information;
    다중 mmWave 셀간 간섭이 발생하면, 상기 다중 mmWave 셀간 간섭을 고려하여 수정된 자원 할당 구성 정보를 상기 송신기를 제어하여 상기 TAG 내의 모든 mmWave 기지국들로 전송하도록 더 구성되는, 장치.And if multiple mmWave inter-cell interference occurs, further modifying the resource allocation configuration information in consideration of the multiple mmWave inter-cell interference to control the transmitter to transmit to all mmWave base stations in the TAG.
  10. 제9항에 있어서,The method of claim 9,
    상기 수정된 자원 할당 구성 정보는 상기 자원 할당 구성 정보가 변경된 mmWave 기지국의 식별자, 변경된 mmWave 셀 인덱스 및 수정된 mmWave 셀 유지 시간 정보가 포함되는, 장치.And wherein the modified resource allocation configuration information includes an identifier of an mmWave base station whose resource allocation configuration information has changed, a changed mmWave cell index, and a modified mmWave cell retention time information.
PCT/KR2016/004415 2016-04-27 2016-04-27 Resource allocation method and device in wireless access system supporting millimeter wave WO2017188471A1 (en)

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