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WO2017159995A1 - Procédé d'estimation de canal de commande et équipement utilisateur pour le mettre en œuvre - Google Patents

Procédé d'estimation de canal de commande et équipement utilisateur pour le mettre en œuvre Download PDF

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Publication number
WO2017159995A1
WO2017159995A1 PCT/KR2017/001586 KR2017001586W WO2017159995A1 WO 2017159995 A1 WO2017159995 A1 WO 2017159995A1 KR 2017001586 W KR2017001586 W KR 2017001586W WO 2017159995 A1 WO2017159995 A1 WO 2017159995A1
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Prior art keywords
reference signal
csi
channel estimation
channel
transmission mode
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English (en)
Korean (ko)
Inventor
정만영
양윤오
이상욱
임수환
황진엽
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LG Electronics Inc
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LG Electronics Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/12—Wireless traffic scheduling

Definitions

  • the present invention relates to mobile communications.
  • 3GPP LTE Long Term Evolution
  • UMTS Universal Mobile Telecommunications System
  • OFDMA Orthogonal Frequency Division Multiple Access
  • SC-FDMA Single Carrier-Frequency Division Multiple Access
  • LTE is divided into a frequency division duplex (FDD) scheme and a time division duplex (TDD) scheme.
  • FDD frequency division duplex
  • TDD time division duplex
  • the physical channel in LTE is a downlink channel PDSCH (Physical Downlink) It may be divided into a shared channel (PDCCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH) which are uplink channels.
  • PDSCH Physical Downlink
  • PUSCH physical uplink shared channel
  • PUCCH physical uplink control channel
  • the reference signal is a signal known in advance between the transmitter and the receiver together with the transmission information. Since the transmission information transmitted from the transmitter undergoes a corresponding channel for each transmission antenna or layer, the reference signal may be allocated for each transmission antenna or layer. Reference signals for each transmission antenna or layer may be distinguished by using resources such as time, frequency, and code.
  • Another disclosure of the present disclosure aims to provide a user device capable of performing improved channel estimation in an environment of moving at high speed or in an environment in which channel conditions are poor.
  • one disclosure of the present specification provides a method for estimating a channel by a user equipment (UE).
  • the method may further include determining a transmission mode to be used for data reception based on antenna information included in configuration information about a radio resource, and based on the determined transmission mode, configuration information about a first reference signal. Determining whether can be dedicated to the second reference signal, and if it is determined that the dedicated is possible, recognize the received first reference signal as the second reference signal, and the channel using the recognized second reference signal And performing an estimation.
  • the second reference signal is a reference signal for demodulation and channel estimation of the data
  • the first reference signal recognized as the second reference signal is a reference signal for obtaining channel state information.
  • the second reference signal may be divided and allocated to two Orthogonal Frequency Division Multiple (OFDM) symbols according to a mapping method other than spreading according to Orthogonal Cover Code (OCC) 2.
  • OFDM Orthogonal Frequency Division Multiple
  • OCC Orthogonal Cover Code
  • the first reference signal In the determining whether the dedicated information is available, the first reference signal is not used in the determined transmission mode, but when configuration information on the first reference signal is received, configuration information on the first reference signal is determined by the second reference signal. It can be determined that the reference signal can be dedicated.
  • the channel estimation may include performing channel estimation by simultaneously using a third reference signal and the recognized second reference signal which are commonly used for channel estimation by all terminals in a cell to which the UE belongs.
  • the antenna port for the second reference signal may be mapped in the same manner as the antenna port for the third reference signal.
  • the antenna information when the antenna information is set to a default value, it may be determined that any one of transmission modes 1 to 6 is used to receive the data.
  • the wireless device may include a radio frequency (RF) unit for transmitting and receiving a radio signal and a processor controlling the RF unit.
  • the processor determines a transmission mode to be used for data reception based on antenna information included in configuration information for a radio resource, and based on the determined transmission mode, configuration information about the first reference signal. Determining whether can be dedicated to the second reference signal, and if it is determined that the dedicated is possible, recognize the received first reference signal as the second reference signal, channel estimation using the recognized second reference signal The procedure to perform the procedure can be performed.
  • RF radio frequency
  • improved channel estimation can be performed in an environment of moving at high speed or in an environment in which channel conditions are poor.
  • 1 is a wireless communication system.
  • FIG. 2 shows a structure of a radio frame according to FDD in 3GPP LTE.
  • 3 shows a structure of a downlink radio frame according to TDD in 3GPP LTE.
  • FIG. 4 is an exemplary diagram illustrating a resource grid for one uplink or downlink slot in 3GPP LTE.
  • 5 shows a structure of a downlink subframe.
  • FIG. 6 shows a structure of an uplink subframe in 3GPP LTE.
  • FIG. 7 is a comparative example of a single carrier system and a carrier aggregation system.
  • FIG. 8 illustrates cross-carrier scheduling in a carrier aggregation system.
  • FIG. 13 and 14 illustrate some examples of receivers according to antenna virtualization.
  • 15 and 16 are some examples in which Assisted-RS is allocated according to the present specification.
  • 17 is a flowchart illustrating a channel estimation method according to one disclosure of the present specification.
  • FIG. 18 is a block diagram illustrating a wireless communication system in which a disclosure of the present specification is implemented.
  • LTE includes LTE and / or LTE-A.
  • first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.
  • first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.
  • base station which is used hereinafter, generally refers to a fixed station for communicating with a wireless device, and includes an evolved-nodeb (eNodeB), an evolved-nodeb (eNB), a base transceiver system (BTS), and an access point (e. Access Point) may be called.
  • eNodeB evolved-nodeb
  • eNB evolved-nodeb
  • BTS base transceiver system
  • access point e. Access Point
  • UE User Equipment
  • UE User Equipment
  • SS Subscriber Station
  • MT Mobile Terminal
  • 1 is a wireless communication system.
  • a wireless communication system includes at least one base station (BS) 20.
  • Each base station 20 provides a communication service for a particular geographic area (generally called a cell) 20a, 20b, 20c.
  • the cell can in turn be divided into a number of regions (called sectors).
  • the UE typically belongs to one cell, and the cell to which the UE belongs is called a serving cell.
  • a base station that provides a communication service for a serving cell is called a serving BS. Since the wireless communication system is a cellular system, there are other cells adjacent to the serving cell. Another cell adjacent to the serving cell is called a neighbor cell.
  • a base station that provides communication service for a neighbor cell is called a neighbor BS. The serving cell and the neighbor cell are determined relatively based on the UE.
  • downlink means communication from the base station 20 to the UE 10
  • uplink means communication from the UE 10 to the base station 20.
  • the transmitter may be part of the base station 20 and the receiver may be part of the UE 10.
  • the transmitter may be part of the UE 10 and the receiver may be part of the base station 20.
  • the wireless communication system includes a multiple-input multiple-output (MIMO) system, a multiple-input single-output (MIS) system, a single-input single-output (SISO) system, and a single-input multiple-output (SIMO) system.
  • MIMO multiple-input multiple-output
  • MIS multiple-input single-output
  • SISO single-input single-output
  • SIMO single-input multiple-output
  • the MIMO system uses a plurality of transmit antennas and a plurality of receive antennas.
  • the MISO system uses multiple transmit antennas and one receive antenna.
  • the SISO system uses one transmit antenna and one receive antenna.
  • the SIMO system uses one transmit antenna and multiple receive antennas.
  • the transmit antenna means a physical or logical antenna used to transmit one signal or stream
  • the receive antenna means a physical or logical antenna used to receive one signal or stream.
  • a wireless communication system can be largely divided into a frequency division duplex (FDD) scheme and a time division duplex (TDD) scheme.
  • FDD frequency division duplex
  • TDD time division duplex
  • uplink transmission and downlink transmission are performed while occupying different frequency bands.
  • uplink transmission and downlink transmission are performed at different times while occupying the same frequency band.
  • the channel response of the TDD scheme is substantially reciprocal. This means that the downlink channel response and the uplink channel response are almost the same in a given frequency domain. Therefore, in a TDD based wireless communication system, the downlink channel response can be obtained from the uplink channel response.
  • the downlink transmission by the base station and the uplink transmission by the UE cannot be performed at the same time.
  • uplink transmission and downlink transmission are performed in different subframes.
  • the radio frame illustrated in FIG. 2 may refer to section 5 of 3GPP TS 36.211 V10.4.0 (2011-12) "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 10)".
  • E-UTRA Evolved Universal Terrestrial Radio Access
  • Physical Channels and Modulation Release 10
  • a radio frame includes 10 subframes, and one subframe includes two slots. Slots in a radio frame are numbered from 0 to 19 slots.
  • the time taken for one subframe to be transmitted is called a Transmission Time Interval (TTI).
  • TTI may be referred to as a scheduling unit for data transmission.
  • one radio frame may have a length of 10 ms
  • one subframe may have a length of 1 ms
  • one slot may have a length of 0.5 ms.
  • the structure of the radio frame is merely an example, and the number of subframes included in the radio frame or the number of slots included in the subframe may be variously changed.
  • one slot may include a plurality of OFDM symbols. How many OFDM symbols are included in one slot may vary depending on a cyclic prefix (CP).
  • CP cyclic prefix
  • 3 is 3GPP In LTE TDD The structure of the downlink radio frame is shown.
  • the radio frame includes 10 subframes indexed from 0 to 9.
  • One subframe includes two consecutive slots.
  • one subframe may have a length of 1 ms, and one slot may have a length of 0.5 ms.
  • One slot may include a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain.
  • OFDM symbol is only for representing one symbol period in the time domain, since 3GPP LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) in downlink (DL), multiple access scheme or name There is no limit on.
  • OFDM symbol may be called by another name such as a single carrier-frequency division multiple access (SC-FDMA) symbol, a symbol period, or the like.
  • SC-FDMA single carrier-frequency division multiple access
  • One slot includes 7 OFDM symbols as an example, but the number of OFDM symbols included in one slot may vary according to the length of the CP.
  • One slot in a normal CP includes 7 OFDM symbols and one slot in an extended CP includes 6 OFDM symbols.
  • a resource block is a resource allocation unit and includes a plurality of subcarriers in one slot. For example, if one slot includes 7 OFDM symbols in the time domain and the resource block includes 12 subcarriers in the frequency domain, one resource block includes 7 ⁇ 12 resource elements (REs). It may include.
  • a subframe having indexes # 1 and # 6 is called a special subframe and includes a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS).
  • DwPTS is used for initial cell search, synchronization or channel estimation at the UE.
  • UpPTS is used to synchronize channel estimation at the base station with uplink transmission synchronization of the UE.
  • GP is a section for removing interference caused in the uplink due to the multipath delay of the downlink signal between the uplink and the downlink.
  • a DL (DownLink) subframe and an UL (UpLink) subframe coexist in one radio frame.
  • Table 1 shows an example of configuration of a radio frame.
  • 'D' represents a DL subframe
  • 'U' represents a UL subframe
  • 'S' represents a special subframe.
  • the UE may know which subframe is the DL subframe or the UL subframe according to the configuration of the radio frame.
  • the DL (downlink) subframe is divided into a control region and a data region in the time domain.
  • the control region includes up to three OFDM symbols preceding the first slot in the subframe, but the number of OFDM symbols included in the control region may be changed.
  • PDCCH and other control channels are allocated to the control region, and PDSCH is allocated to the data region.
  • an uplink slot includes a plurality of OFDM symbols in a time domain and includes N RB resource blocks (RBs) in a frequency domain.
  • N RB resource blocks For example, in the LTE system, the number of resource blocks (RBs), that is, N RBs may be any one of 6 to 110.
  • the RB is also called a physical resource block (PRB).
  • one resource block RB includes 7x12 resource elements RE including 7 OFDM symbols in a time domain and 12 subcarriers in a frequency domain, but the number of subcarriers in a resource block is exemplarily described.
  • the number of OFDM symbols is not limited thereto.
  • the number of OFDM symbols or the number of subcarriers included in the resource block may be variously changed. That is, the number of OFDM symbols may change according to the length of the above-described CP.
  • 3GPP LTE defines that 7 OFDM symbols are included in one slot in the case of a regular CP, and 6 OFDM symbols in one slot in the case of an extended CP.
  • the OFDM symbol is for representing one symbol period, and may be referred to as an SC-FDMA symbol, an OFDMA symbol, or a symbol period according to a system.
  • the RB includes a plurality of subcarriers in the frequency domain in resource allocation units.
  • the number N UL of resource blocks included in an uplink slot depends on an uplink transmission bandwidth set in a cell.
  • Each element on the resource grid is called a resource element (RE).
  • the number of subcarriers in one OFDM symbol can be used to select one of 128, 256, 512, 1024, 1536 and 2048.
  • a resource grid for one uplink slot may be applied to a resource grid for a downlink slot.
  • 5 shows a structure of a downlink subframe.
  • 7 OFDM symbols are included in one slot by assuming a normal CP.
  • the number of OFDM symbols included in one slot may change according to the length of a cyclic prefix (CP). That is, as described above, according to 3GPP TS 36.211 V10.4.0, one slot includes 7 OFDM symbols in a normal CP, and one slot includes 6 OFDM symbols in an extended CP.
  • CP cyclic prefix
  • the DL (downlink) subframe is divided into a control region and a data region in the time domain.
  • the control region includes up to three OFDM symbols preceding the first slot in the subframe, but the number of OFDM symbols included in the control region may be changed.
  • a physical downlink control channel (PDCCH) and another control channel are allocated to the control region, and a PDSCH is allocated to the data region.
  • PDCH physical downlink control channel
  • physical channels include a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), a physical downlink control channel (PDCCH), a physical control format indicator channel (PCFICH), and a physical hybrid (PHICH).
  • PDSCH physical downlink shared channel
  • PUSCH physical uplink shared channel
  • PDCCH physical downlink control channel
  • PCFICH physical control format indicator channel
  • PHICH physical hybrid
  • ARQ Indicator Channel Physical Uplink Control Channel
  • the PCFICH transmitted in the first OFDM symbol of the subframe carries a Control Format Indicator (CFI) regarding the number of OFDM symbols (that is, the size of the control region) used for transmission of control channels in the subframe.
  • CFI Control Format Indicator
  • the wireless device first receives the CFI on the PCFICH and then monitors the PDCCH.
  • the PCFICH does not use blind decoding and is transmitted on a fixed PCFICH resource of a subframe.
  • PHICH carries a positive-ACKnowledgement (ACK) / Negative-ACKnowledgement (NACK) signal for UL HARQ (Hybrid Automatic Repeat reQuest).
  • ACK positive-ACKnowledgement
  • NACK Negative-ACKnowledgement
  • the ACK / NACK signal for the UL data on the PUSCH transmitted by the wireless device is transmitted on the PHICH.
  • the Physical Broadcast Channel (PBCH) is transmitted in the preceding four OFDM symbols of the second slot of the first subframe of the radio frame.
  • the PBCH carries system information necessary for the wireless device to communicate with the base station, and the system information transmitted through the PBCH is called a master information block (MIB).
  • MIB master information block
  • SIB system information block
  • PDCCH includes resource allocation and transmission format of downlink-shared channel (DL-SCH), resource allocation information of uplink shared channel (UL-SCH), paging information on PCH, system information on DL-SCH, and random access transmitted on PDSCH. Resource allocation of higher layer control messages such as responses, sets of transmit power control commands for individual UEs in any UE group, activation of Voice over Internet Protocol (VoIP), and the like.
  • a plurality of PDCCHs may be transmitted in the control region, and the UE may monitor the plurality of PDCCHs.
  • the PDCCH is transmitted on an aggregation of one or several consecutive 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.
  • 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 CCE
  • DCI downlink control information
  • PDSCH also called DL grant
  • PUSCH resource allocation also called UL grant
  • VoIP Voice over Internet Protocol
  • the base station determines the PDCCH format according to the DCI to be sent to the UE, and attaches a CRC (Cyclic Redundancy Check) to the control information.
  • the CRC masks a unique Radio Network Temporary Identifier (RNTI) according to the owner or purpose of the PDCCH. If the PDCCH is for a specific UE, a unique identifier of the UE, for example, a C-RNTI (Cell-RNTI), may be masked to the CRC. Alternatively, if the PDCCH is for a paging message, a paging indication identifier, for example, P-RNTI (P-RNTI), may be masked to the CRC.
  • P-RNTI P-RNTI
  • SI-RNTI system information-RNTI
  • RA-RNTI random access-RNTI
  • blind decoding is used to detect the PDCCH.
  • Blind decoding is a method of demasking a desired identifier in a cyclic redundancy check (CRC) of a received PDCCH (referred to as a candidate PDCCH) and checking a CRC error to determine whether the corresponding PDCCH is its control channel.
  • the base station determines the PDCCH format according to the DCI to be sent to the wireless device, attaches the CRC to the DCI, and masks a unique identifier (RNTI) to the CRC according to the owner or purpose of the PDCCH.
  • RNTI unique identifier
  • the control region in the subframe includes a plurality of control channel elements (CCEs).
  • the CCE is a logical allocation unit used to provide a coding rate according to the state of a radio channel to a PDCCH and corresponds to a plurality of resource element groups (REGs).
  • the REG includes a plurality of resource elements RE.
  • 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.
  • One REG includes four REs and one CCE includes nine REGs.
  • ⁇ 1, 2, 4, 8 ⁇ CCEs may be used to configure one PDCCH, and each element of ⁇ 1, 2, 4, 8 ⁇ is called a CCE aggregation level.
  • the number of CCEs used for transmission of the PDCCH is determined by the base station according to the channel state. For example, one CCE may be used for PDCCH transmission for a UE having a good downlink channel state. Eight CCEs may be used for PDCCH transmission for a UE having a poor downlink channel state.
  • a control channel composed of one or more CCEs performs interleaving in units of REGs and is mapped to physical resources after a cyclic shift based on a cell identifier is performed.
  • the UE cannot know which CCE aggregation level or DCI format is transmitted at which position in the PDCCH of the control region. Since a plurality of PDCCHs may be transmitted in one subframe, the UE monitors the plurality of PDCCHs in every subframe. Here, monitoring means that the UE attempts to decode the PDCCH according to the PDCCH format.
  • a search space is used to reduce the burden of blind decoding.
  • the search space may be referred to as a monitoring set of the CCE for the PDCCH.
  • the UE monitors the PDCCH in the corresponding search space.
  • a DCI format and a search space to be monitored are determined according to a transmission mode (TM) of the PDSCH.
  • TM transmission mode
  • Transmission mode DCI format Search space PDSCH Transmission Mode According to PDCCH Transfer mode 1 DCI format 1A Public and terminal specific Single antenna port, port 0 DCI format 1 Terminal specific Single antenna port, port 0 Transfer mode 2 DCI format 1A Public and terminal specific Transmit diversity DCI format 1 Terminal specific Transmission diversity Transmission mode 3 DCI format 1A Public and terminal specific Transmission diversity DCI format 2A Terminal specific Cyclic Delay Diversity (CDD) or Transmit Diversity Transmission mode 4 DCI format 1A Public and terminal specific Transmission diversity DCI format 2 Terminal specific Closed-loop spatial multiplexing Transmission mode 5 DCI format 1A Public and terminal specific Transmission diversity DCI format 1D Terminal specific Multi-user Multiple Input Multiple Output (MU-MIMO) Transmission mode 6 DCI format 1A Public and terminal specific Transmission diversity DCI format 1B Terminal specific Closed Loop Space Multiplexing Transmission mode 7 DCI format 1A Public and terminal specific Single antenna port, port 0, or transmit diversity if the number of PBCH transmit ports is 1 DCI format 1 Terminal specific Single antenna port, port 5 Transmission mode 8 DCI format 1A Public
  • the uses of the DCI format are classified as shown in the following table.
  • DCI format Contents DCI format 0 Used for PUSCH scheduling DCI format 1 Used for scheduling one PDSCH codeword DCI format 1A Used for compact scheduling and random access of one PDSCH codeword DCI format 1B Used for simple scheduling of one PDSCH codeword with precoding information DCI format 1C Used for very compact scheduling of one PDSCH codeword DCI format 1D Used for simple scheduling of one PDSCH codeword with precoding and power offset information DCI format 2 Used for PDSCH scheduling of terminals configured in closed loop spatial multiplexing mode DCI format 2A Used for PDSCH scheduling of terminals configured in an open-loop spatial multiplexing mode DCI format 2B DCI format 2B is used for resource allocation for dual-layer beamforming of the PDSCH.
  • DCI format 2C DCI format 2C is used for resource allocation for up to eight layers of closed-loop SU-MIMO or MU-MIMO operation.
  • DCI format 2D DCI format 2C is used for resource allocation of up to eight layers.
  • DCI format 3 Used to transmit TPC commands of PUCCH and PUSCH with 2-bit power adjustments
  • DCI format 3A Used to transmit TPC commands of PUCCH and PUSCH with 1-bit power adjustment
  • DCI format 4 Used for PUSCH scheduling of uplink (UL) cell operating in multi-antenna port transmission mode
  • the uplink channel includes a PUSCH, a PUCCH, a sounding reference signal (SRS), and a physical random access channel (PRACH).
  • PUSCH PUSCH
  • PUCCH Physical Uplink Control Channel
  • SRS sounding reference signal
  • PRACH physical random access channel
  • the PDCCH is monitored in a limited region called a control region in a subframe, and the CRS transmitted in all bands is used for demodulation of the PDCCH.
  • the type of control information is diversified and the amount of control information is increased, the scheduling flexibility is inferior to the existing PDCCH alone.
  • EPDCCH enhanced PDCCH
  • an uplink subframe may be divided into a control region and a data region in the frequency domain.
  • a physical uplink control channel (PUCCH) for transmitting uplink control information is allocated to the control region.
  • the data area is allocated a PUSCH (Physical Uplink Shared Channel) for transmitting data (in some cases, control information may also be transmitted).
  • PUSCH Physical Uplink Shared Channel
  • PUCCH for one UE is allocated to an RB pair in a subframe.
  • Resource blocks belonging to a resource block pair occupy different subcarriers in each of a first slot and a second slot.
  • the frequency occupied by RBs belonging to the RB pair allocated to the PUCCH is changed based on a slot boundary. This is called that the RB pair allocated to the PUCCH is frequency-hopped at the slot boundary.
  • the UE may obtain frequency diversity gain by transmitting uplink control information through different subcarriers over time.
  • m is a location index indicating a logical frequency domain location of a resource block pair allocated to a PUCCH in a subframe.
  • the uplink control information transmitted on the PUCCH includes HARQ (Hybrid Automatic Repeat reQuest) ACK (Non-ACKnowledgement) / NACK (Non-ACKnowledgement), Channel Quality Indicator (CQI) indicating the downlink channel state, SR which is an uplink radio resource allocation request. (Scheduling Request).
  • HARQ Hybrid Automatic Repeat reQuest
  • ACK Non-ACKnowledgement
  • NACK Non-ACKnowledgement
  • CQI Channel Quality Indicator
  • the PUSCH is mapped to the UL-SCH, which is a transport channel.
  • the uplink data transmitted on the PUSCH may be a transport block which is a data block for the UL-SCH transmitted during the transmission time interval (TTI).
  • the transport block may be user information.
  • the uplink data may be multiplexed data.
  • the multiplexed data may be a multiplexed transport block and control information for the UL-SCH.
  • CA Carrier Aggregation
  • FIG. 7 is a comparative example of a single carrier system and a carrier aggregation system.
  • a single carrier in uplink and downlink.
  • the bandwidth of the carrier may vary, but only one carrier is allocated to the UE.
  • a carrier aggregation (CA) system a plurality of component carriers (DL CC A to C, UL CC A to C) can be allocated to the UE.
  • Component Carrier (CC) refers to a carrier used in a carrier aggregation system and may be abbreviated as a carrier. For example, three 20 MHz component carriers may be allocated to allocate a 60 MHz bandwidth to the UE.
  • the carrier aggregation system may be divided into a contiguous carrier aggregation system in which aggregated carriers are continuous and a non-contiguous carrier aggregation system in which aggregated carriers are separated from each other.
  • a carrier aggregation system simply referred to as a carrier aggregation system, it should be understood to include both the case where the component carrier is continuous and the case where it is discontinuous.
  • the number of component carriers aggregated between the downlink and the uplink may be set differently. The case where the number of downlink CCs and the number of uplink CCs are the same is called symmetric aggregation, and when the number is different, it is called asymmetric aggregation.
  • the target carrier may use the bandwidth used by the existing system as it is for backward compatibility with the existing system.
  • the 3GPP LTE system supports bandwidths of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz, and the 3GPP LTE-A system may configure a bandwidth of 20 MHz or more using only the bandwidth of the 3GPP LTE system.
  • broadband can be configured by defining new bandwidth without using the bandwidth of the existing system.
  • the system frequency band of a wireless communication system is divided into a plurality of carrier frequencies.
  • the carrier frequency means a center frequency of a cell.
  • a cell may mean a downlink frequency resource and an uplink frequency resource.
  • the cell may mean a combination of a downlink frequency resource and an optional uplink frequency resource.
  • CA carrier aggregation
  • the UE In order to transmit and receive packet data through a specific cell, the UE must first complete configuration for a specific cell.
  • the configuration refers to a state in which reception of system information necessary for data transmission and reception for a corresponding cell is completed.
  • configuration is a general process of receiving common physical layer parameters required for data transmission or reception, media access control (MAC) layer parameters, or parameters required for a specific operation in a radio resource control (RRC) layer. It may include.
  • RRC radio resource control
  • the cell in the configuration complete state may exist in an activation or deactivation state.
  • activation means that data is transmitted or received or is in a ready state.
  • the UE may monitor or receive the control channel (PDCCH) and the data channel (PDSCH) of the activated cell in order to identify resources allocated to the UE (which may be frequency, time, etc.).
  • PDCCH control channel
  • PDSCH data channel
  • Deactivation means that transmission or reception of traffic data is impossible, and measurement or transmission of minimum information is possible.
  • the UE may receive system information (SI) required for packet reception from the deactivated cell.
  • SI system information
  • the UE does not monitor or receive the control channel (PDCCH) and the data channel (PDSCH) of the deactivated cell in order to check resources allocated to it (may be frequency, time, etc.).
  • the cell may be divided into a primary cell, a secondary cell, and a serving cell.
  • a primary cell means a cell operating at a primary frequency, and is a cell in which a UE performs an initial connection establishment procedure or a connection reestablishment procedure with a base station, or is indicated as a primary cell in a handover process. It means a cell.
  • the secondary cell refers to a cell operating at the secondary frequency, and is established and used to provide additional radio resources once the RRC connection is established.
  • the serving cell is configured as a primary cell when the carrier aggregation is not set or the UE cannot provide carrier aggregation.
  • the term serving cell indicates a cell configured for the UE and may be configured in plural.
  • One serving cell may be configured with one downlink component carrier or a pair of ⁇ downlink component carrier, uplink component carrier ⁇ .
  • the plurality of serving cells may be configured as a set consisting of one or a plurality of primary cells and all secondary cells.
  • a plurality of CCs that is, a plurality of serving cells, may be supported.
  • Such a carrier aggregation system may support cross-carrier scheduling.
  • Cross-carrier scheduling is a resource allocation of a PDSCH transmitted on another component carrier through a PDCCH transmitted on a specific component carrier and / or other components other than the component carrier basically linked with the specific component carrier.
  • a scheduling method for resource allocation of a PUSCH transmitted through a carrier That is, the PDCCH and the PDSCH may be transmitted through different downlink CCs, and the PUSCH may be transmitted through another uplink CC other than the uplink CC linked with the downlink CC through which the PDCCH including the UL grant is transmitted. .
  • a carrier indicator indicating a DL CC / UL CC through which a PDSCH / PUSCH for which PDCCH provides control information is transmitted is required.
  • a field containing such a carrier indicator is hereinafter referred to as a carrier indication field (CIF).
  • a carrier aggregation system supporting cross carrier scheduling may include a carrier indication field (CIF) in a conventional downlink control information (DCI) format.
  • CIF carrier indication field
  • DCI downlink control information
  • 3 bits may be extended, and the PDCCH structure may include an existing coding method, Resource allocation methods (ie, CCE-based resource mapping) can be reused.
  • FIG. 8 illustrates cross-carrier scheduling in a carrier aggregation system.
  • the base station may set a PDCCH monitoring DL CC (monitoring CC) set.
  • the PDCCH monitoring DL CC set is composed of some DL CCs among the aggregated DL CCs, and when cross-carrier scheduling is set, the UE performs PDCCH monitoring / decoding only for the DL CCs included in the PDCCH monitoring DL CC set. In other words, the base station transmits the PDCCH for the PDSCH / PUSCH to be scheduled only through the DL CC included in the PDCCH monitoring DL CC set.
  • PDCCH monitoring DL CC set may be set UE-specific, UE group-specific, or cell-specific.
  • three DL CCs (DL CC A, DL CC B, and DL CC C) are aggregated, and DL CC A is set to PDCCH monitoring DL CC.
  • the UE may receive the DL grant for the PDSCH of the DL CC A, the DL CC B, and the DL CC C through the PDCCH of the DL CC A.
  • the DCI transmitted through the PDCCH of the DL CC A may include the CIF to indicate which DCI the DLI is.
  • the reference signal is a signal known in advance between the transmitter and the receiver together with the transmission information. Since the transmission information transmitted from the transmitter undergoes a corresponding channel for each transmission antenna or layer, the reference signal may be allocated for each transmission antenna or layer. Reference signals for each transmission antenna or layer may be distinguished by using resources such as time, frequency, and code. The reference signal may be used for two purposes, namely, demodulation of transmission information and channel estimation.
  • reference signals are transmitted in sequence.
  • the reference signal sequence may use a PSK-based computer generated sequence.
  • PSKs include binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK).
  • the reference signal sequence may use a constant amplitude zero auto-correlation (CAZAC) sequence.
  • CAZAC sequences are ZC-based sequences, ZC sequences with cyclic extensions, ZC sequences with truncation, etc. There is this.
  • the reference signal sequence may use a pseudo-random (PN) sequence.
  • PN sequences include m-sequences, computer generated sequences, Gold sequences, and Kasami sequences.
  • the reference signal sequence may use a cyclically shifted sequence.
  • the reference signal may be classified into a cell-specific RS (CRS), an MBSFN reference signal, and a UE-specific RS.
  • CRS is a reference signal transmitted to all terminals in a cell and used for channel estimation.
  • MBSFN reference signal may be transmitted in a subframe allocated for MBSFN transmission.
  • the UE specific reference signal is a reference signal received by a specific terminal or a specific group of terminals in a cell and may be referred to as a dedicated RS (DRS).
  • DRS dedicated RS
  • a specific terminal or a specific terminal group is mainly used for data demodulation.
  • reference signals may be classified according to use.
  • a reference signal used for demodulation of data is called a demodulation RS (DM-RS).
  • a reference signal used for feedback information indicating a channel state such as CQI / PMI / RI is referred to as channel state information-RS (CSI-RS).
  • CSI-RS channel state information-RS
  • the dedicated reference signal DRS described above may be used as a demodulation reference signal DM-RS.
  • FIG. 9 illustrates a case where the base station uses one antenna
  • FIG. 10 illustrates a case where the base station uses two antennas
  • FIG. 11 illustrates an example of a CRS structure when the base station uses four antennas.
  • This may be referred to Section 6.10.1 of 3GPP TS 36.211 V8.2.0 (2008-03).
  • the CRS structure may be used to support the features of the LTE-A system. For example, it may be used to support features such as Coordinated Multi-Point (CoMP) transmission and reception scheme or spatial multiplexing.
  • the CRS may be used for channel quality measurement, CP detection, time / frequency synchronization, and the like.
  • 'R0' indicates a reference signal for the first antenna
  • 'R1' indicates a reference signal for the second antenna
  • 'R2' indicates a reference signal for the third antenna
  • 'R3' indicates a reference signal for the fourth antenna.
  • Positions in subframes of R0 to R3 do not overlap with each other.
  • l is the position of the OFDM symbol in the slot l in the normal CP has a value between 0 and 6.
  • a reference signal for each antenna is located at six subcarrier intervals.
  • the number of R0 and the number of R1 in the subframe is the same, the number of R2 and the number of R3 is the same.
  • the number of R2 and R3 in the subframe is less than the number of R0 and R1. Resource elements used for the reference signal of one antenna are not used for the reference signal of another antenna. This is to avoid interference between antennas.
  • the CRS is always transmitted by the number of antennas regardless of the number of streams.
  • the CRS has an independent reference signal for each antenna.
  • the location of the frequency domain and the location of the time domain in the subframe of the CRS are determined regardless of the UE.
  • the CRS sequence multiplied by the CRS is also generated regardless of the terminal. Therefore, all terminals in the cell can receive the CRS.
  • the position and the CRS sequence in the subframe of the CRS may be determined according to the cell ID.
  • the location in the time domain in the subframe of the CRS may be determined according to the number of the antenna and the number of OFDM symbols in the resource block.
  • the location of the frequency domain in the subframe of the CRS may be determined according to the number of the antenna, the cell ID, the OFDM symbol index l, the slot number in the radio frame, and the like.
  • the CRS sequence may be applied in units of OFDM symbols in one subframe.
  • the CRS sequence may vary according to a cell ID, a slot number in one radio frame, an OFDM symbol index in a slot, a type of CP, and the like.
  • the number of reference signal subcarriers for each antenna on one OFDM symbol is two.
  • the number of reference signal subcarriers for each antenna on one OFDM symbol is 2 ⁇ N RB . Therefore, the length of the CRS sequence is 2 ⁇ N RB .
  • Equation 1 shows an example of the CRS sequence r (m).
  • 2N RB max is the number of resource blocks corresponding to the maximum bandwidth.
  • 2N RB max is 110 in 3GPP LTE system.
  • c (i) is a pseudo random sequence in a PN sequence and may be defined by a Gold sequence of length-31. Equation 2 shows an example of the gold sequence c (n).
  • x 1 (i) is the first m-sequence and x 2 (i) is the second m-sequence.
  • the first m-sequence or the second m-sequence may be initialized for each OFDM symbol according to a cell ID, a slot number in one radio frame, an OFDM symbol index in a slot, a type of CP, and the like.
  • only a predetermined portion of a 2 ⁇ N RB length may be selected and used in a reference signal sequence generated with a 2 ⁇ 2N RB max length.
  • CRS may be used for estimation of channel state information (CSI) in an LTE-A system.
  • CSI channel state information
  • CQI channel quality indicator
  • PMI precoding matrix indicator
  • RI rank indicator
  • the CSI-RS is used for channel estimation for PDSCH of the LTE-A terminal and channel measurement for generating channel information.
  • the CSI-RS may be relatively sparse in the frequency domain or the time domain and may be punctured in the data region of the general subframe or the MBSFN subframe. If necessary through the estimation of the CSI, CQI, PMI and RI may be reported from the terminal.
  • the CSI-RS is transmitted through one, two, four or eight antenna ports.
  • CSI-RS is a 3GPP (3rd Generation Partnership Project) TS 36.211 V10.1.0 (2011-03) "Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation (Release 8)" See section 6.10.5.
  • CSI-RS Inter-cell interference
  • HetNet heterogeneous network
  • the CSI-RS configuration is different depending on the number of antenna ports and the CP in the cell, and adjacent cells may have different configurations as much as possible.
  • the CSI-RS configuration may be divided into a case of applying to both the FDD frame and the TDD frame and the case of applying only to the TDD frame according to the frame structure.
  • a plurality of CSI-RS configurations may be used in one cell. Zero or one CSI-RS configuration for a terminal assuming non-zero power CSI-RS is zero or several CSI-RSs for a terminal assuming zero power CSI-RS.
  • RS configuration may be used.
  • the CSI-RS configuration may be indicated by the higher layer.
  • a CSI-RS-Config information element (IE) transmitted through an upper layer may indicate CSI-RS configuration.
  • the sequence r l, ns (m) for the CSI-RS may be generated as follows.
  • N ID cell means a physical cell ID.
  • the reference signal sequence r l, ns (m) is mapped to a complex value modulation symbol a k, l (p) used as a reference symbol for the antenna port p.
  • the CSI-RS may be transmitted in a downlink slot that satisfies the conditions of Tables 4 and 5 described below by (n s mod 2) (where mod denotes a modular operation, that is, (n s mod 2)). Is the remainder of n s divided by 2).
  • Table 4 below shows the configuration of the CSI-RS in the normal CP
  • Table 5 shows the configuration of the CSI-RS in the extended CP.
  • the UE may transmit the CSI-RS only in the downlink slot that satisfies the condition of n s mod 2 in Tables 4 and 5.
  • the UE may be a subframe or paging in which a special subframe of a TDD frame, transmission of the CSI-RS collides with a synchronization signal, a physical broadcast channel (PBCH), and a system information block type 1 (SystemInformationBlockType1).
  • PBCH physical broadcast channel
  • SystemInformationBlockType1 system information block type 1
  • the CSI of one antenna port The resource element on which -RS is transmitted is not used for transmission of CSI-RS of PDSCH or other antenna port.
  • the table below shows an example of a subframe configuration in which the CSI-RS is transmitted.
  • the period (T CSI - RS ) and the offset ( ⁇ CSI-RS ) of the subframe in which the CSI-RS is transmitted may be determined according to the CSI-RS subframe configuration (I CSI - RS ).
  • the CSI-RS subframe configuration of the above table may be any one of a 'SubframeConfig' field or a 'ZeroTxPowerSubframeConfig' field of the CSI-RS-Config IE.
  • the CSI-RS subframe configuration may be configured separately for the non-zero power CSI-RS and zero-power CSI-RS.
  • the present specification proposes a reference signal RS that can assist the CRS in an environment in which a channel state is poor, such as an environment of moving at high speed or a cell boundary.
  • channel estimation may be performed by using an existing CRS together with an auxiliary reference signal, thereby improving performance of channel estimation.
  • the channel estimation method proposed in this specification can improve the performance of channel estimation of a terminal supporting an auxiliary reference signal without affecting the operation of an existing terminal that does not support the auxiliary reference signal.
  • the auxiliary reference signal proposed in the present specification can minimize the waste of radio resources by dynamically controlling the overhead according to the environment.
  • the auxiliary reference signal proposed herein is referred to as an Assisted RS (Reference Signal) or A-RS.
  • the LTE-A specification after 3GPP release 10 introduced the concept of antenna virtualization along with a transmission mode (TM) 9 transmission mode including CSI-RS and DMRS.
  • 13 and 14 show the antenna In virtualization Some examples of receivers are shown.
  • FIG. 13 is a receiver in LTE according to antenna virtualization
  • FIG. 14 is a receiver in LTE-A according to antenna virtualization. 13 and 14, with the introduction of antenna virtualization, it is possible to support more antenna ports in the TM 9 or TM 10 transmission mode while minimizing the overhead increase of the reference signal. However, since an additionally introduced reference signal is transmitted through different radio channels in concept, channel estimation cannot be performed by mixing heterogeneous reference signals.
  • the present specification utilizes the structure of the CSI-RS to map the Assisted-RS to use the same antenna port as the CRS used in the TM 1 to TM 6 transmission modes, thereby simultaneously using the CRS and the Assisted-RS to estimate the channel. It is suggested to improve the performance.
  • UE L Legacy UE of 3GPP Release 8 or 9. UE L does not support CSI-RS.
  • UE L10 This is a legacy UE of 3GPP Release 10. UE L10 supports one CSI-RS.
  • UE L11 Legacy UE after 3GPP Release 11.
  • UE L11 supports one CSI-RS, three NZP CSI-RSs (Non-Zero Power CSI-RS), and four ZP CSI-RSs (Zero CSI-RS).
  • UE A UE that supports Assisted-RS according to the present specification.
  • P CRS, CSI P - A- P RS and RS are each CRS, the antenna port of the CSI-RS and RS-Assisted.
  • CRS N, N CSI - RS and RS A- N is the number of antenna ports respectively in the CRS, CSI-RS and RS-Assisted.
  • the UE A may configure the specific CSI-RS among the configuration information for the CSI-RS received from the base station. Recognize that it is about RS.
  • the CSI-RS information includes RRC setup, RRC reconfiguration, RRC reestablishment, and addition of a secondary cell (SCell) of carrier aggregation (CA).
  • SCell secondary cell
  • CA carrier aggregation
  • the RadioResourceConfigDedicated may be included in the IE (Information Element) and transmitted. The above signaling is defined in 3GPP TS 36.331 as follows.
  • the CSI-RS configuration information included in the above-described structure may be slightly different in 3GPP Release 10 and Release 11, but the basic form is not very different.
  • the configuration of the CSI-RS-Config IE is described in 3GPP TS 36.331 as follows.
  • the 'antennaPortsCount' field indicates the number of antenna ports used for transmission of the CSI-RS.
  • the 'resourceConfig' field indicates CSI-RS configuration.
  • the 'SubframeConfig' field and the 'zeroTxPowerSubframeConfig' field indicate the subframe configuration in which the CSI-RS is transmitted.
  • the 'zeroTxPowerResourceConfigList' field indicates the configuration of zero-power CSI-RS.
  • a CSI-RS configuration corresponding to a bit set to 1 in a 16-bit bitmap constituting the 'zeroTxPowerResourceConfigList' field may be set to zero-power CSI-RS.
  • the antenna port used by the CSI-RS channel is as physically as possible as the antenna port of the CRS.
  • the CSI-RS be interpreted as Assisted-RS from the UE A 's perspective and interpreted as CSI-RS from the UE L , UE L10 or UE L11's perspective.
  • UE A may further use channel Assisted-RS to improve channel estimation performance.
  • the present specification by adjusting the configuration of the CSI-RS to adjust the size of the overhead additionally required by the reference signal, it is possible to properly adjust between the channel estimation performance and the overhead.
  • UE L since UE L does not support CSI-RS, it does not recognize the existence of CSI-RS-Config itself. Therefore, when performing scheduling for UE L in a subframe to which CSI-RS is allocated, UE L is a CSI-RS resource element (RE) present in a resource block (RB) allocated to itself among CSI-RS channels. It is regarded as its PDSCH resource element and received, resulting in performance degradation. This problem is a problem occurring after 3GPP release 10, regardless of the Assisted-RS proposed in this specification, and can be avoided through proper scheduling of the base station.
  • RE CSI-RS resource element
  • UE L10 supports at most one CSI-RS.
  • a base station supporting Assisted-RS according to the present specification may be assumed to use at least min (N CRS , N CSI-RS ) antennas equally between a physical antenna for CRS and a physical antenna for CSI-RS . have. In this case, even if the CSI-RS of the subframe is dedicated to the Assisted RS, there is no problem in the operation of the TM 9 transmission mode of the UE L10 .
  • UE A may operate as follows in a subframe to which CSI-RS that can be dedicated to Assisted-RS is allocated.
  • N CSI - N CRS ⁇ N CSI - RS cases: N CSI - since the CSI-RS of N CRS one by one RS is transmitted at the same antenna port and the CRS, with the CRS and CSI-RS at the same time a gain in channel estimation performance You can get it.
  • N CSI among N CRS - RS can be performed using CRS and CSI-RS at the same time, but channel estimation is performed using only CRS for antenna ports corresponding to N CSI - RS + 1 to N CRS . Only gain can be obtained.
  • U L11 supports a plurality of CSI-RS configurations to support cooperative multi-point (CoMP)
  • UE L11 adds additionally allocated CSI-RS to Assisted RS in addition to CSI-RS associated with CSI processing. It does not affect operation.
  • channel estimation is performed by simultaneously using an Assisted RS and a CRS allocated to an existing CSI-RS, thereby obtaining channel estimation performance.
  • channel estimation performance can be gained.
  • Such channel estimation performance can be maximized in an environment in which channel conditions are poor, such as an environment of moving at high speed or a cell boundary.
  • the detailed operation based on the 3GPP Release 10 specification is as follows.
  • the value of antenaInfo-r10 in the RadioResourceConfigDedicated IE sent to UE A is set to Null, which is the default value, or set to TM 1, TM 2, TM 3, TM 4, TM 5, TM 6, TM 7 or TM 8-v920 If so, UE A uses existing transmission modes (TM 1 through TM 6).
  • the UE A regards the CSI-RS included in the designated subframe as the Assisted-RS.
  • the UE L10 cannot operate in the TM 9 transmission mode. Therefore, it is possible for the UE L10 9 TM transmission modes specifying a CSI-RS is assigned to the sub-frame that does not overlap with Assisted-RS, and solve the problem by not scheduling in the sub-frame.
  • UE A recognizes the CSI-RS allocated to a specific subframe as an Assisted-RS, UE A performs channel estimation by simultaneously using the basic CRS and Assisted-RS in TM 1 to TM 6 transmission modes performed based on the CRS. As a result, overall performance gain including channel estimation performance improvement according to the increased frequency of the reference signal RS on the time axis can be obtained.
  • the number of reference signal overheads can be minimized by performing resource allocation using spreading of Orthogonal Cover Code (OCC) 2.
  • OCC Orthogonal Cover Code
  • the CSI-RS when the CSI-RS operates as an Assisted-RS, the OCC 2 spreading may not be used. Therefore, the CSI-RS can be allocated by dividing it into a case where l ′′ is 0 and a case where 1 is used. In the channel estimation position of the receiver, when the Assisted-RS is divided and allocated to two OFDM symbols, the channel estimation can be performed independently without performing OCC 2 despreading. Therefore, the frequency of the reference signal is increased on the time axis. You can.
  • mapping of the CSI-RS of the LTE-A standard has been described above with reference to FIG. 12.
  • 16 0 allocated to the same position is not allocated to maintain orthogonality. Accordingly, an example of antenna port mapping between the CSI-RS and the CRS will be described in the following table.
  • the reference signal allocated to the Assisted-RS has been proposed to maximize the frequency of the reference signal in the time axis region.
  • the conventional CRS is reduced by half compared to the antenna port 0/1 in the antenna port 2/3, it is proposed to increase the antenna port 2/3 preferentially.
  • the corresponding CSI-RS is not transmitted.
  • the antenna port denoted by N means that the Assisted-RS does not exist in the corresponding CRS port.
  • mapping proposed in the above table is only one embodiment according to the present specification, and it is obvious that the mapping may be changed to map to another antenna port according to a required environment.
  • the signal may be mapped to an antenna port different from the above table.
  • 15 and 16 are some examples in which Assisted-RS is allocated according to the present specification.
  • FIG. 15 and 16 are some examples of mapping the 8 CSI-RS antenna ports to the CRS antenna ports as Assisted-RS according to Table 9 above, and FIG. 15 is one of Assisted-RS mapping to improve time axis resolution performance. 16 shows an example of Assisted-RS mapping for improving frequency axis resolution performance.
  • the performance of channel estimation can be improved by additionally using Assisted-RS utilizing the structure of the CSI-RS. Can be. In addition, it is also possible to expect an improvement in reception performance of the UE according to improved channel estimation.
  • 17 is a flowchart illustrating a channel estimation method according to one disclosure of the present specification.
  • the UE receives configuration information on a radio resource (S100).
  • the UE may receive a RadioResouceConfigDedicated IE from the RRC layer.
  • the RadioResouceConfigDedicated IE may include a value of antenaInfo-r10 for an antenna to be used for data reception.
  • the UE determines a transmission mode TM to be used for data reception based on the antenna information included in the configuration information for the radio resource (S200). Specifically, the UE has the value of antenaInfo-r10 included in the RadioResouceConfigDedicated IE set to Null, which is the default value, or TM 1, TM 2, TM 3, TM 4, TM 5, TM 6, TM 7 or TM 8-v920 If set to UEA, the UEA may decide to use existing transmission modes (TM 1 to TM 6).
  • the UE determines whether configuration information (ie, CSI-RS-Config) for the CSI-RS can be dedicated to the Assisted-RS based on the determined transmission mode (S300). Specifically, the UE is determined to use the existing transmission mode (TM 1 to TM 6), but if the configuration information for the CSI-RS is received through the CSI-RS-Config through the CSI-RS-Config, CSI It is possible to determine whether the RS-Config can be transmitted to the Assisted-RS.
  • the Assisted-RS can be used for channel estimation independently without performing spreading according to OCC 2 by splitting and assigning two OFDM symbols without using spreading according to OCC 2.
  • the UE When the CSI-RS-Config can be dedicated to the Assisted-RS, the UE recognizes the CSI-RS as the Assisted-RS when a subframe including the CSI-RS is received and simultaneously uses the recognized Assisted-RS and the CRS. Channel estimation is performed (S400). In this case, the UE may perform channel estimation using both Assisted-RS and CRS simultaneously, thereby improving performance of channel estimation in an environment in which channel conditions are poor, such as a fast moving environment or a cell boundary.
  • Embodiments of the present invention described so far may be implemented through various means.
  • embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof. Specifically, it will be described with reference to the drawings.
  • Block diagram illustrates a wireless communication system in which the present disclosure is implemented.
  • the base station 200 includes a processor 201, a memory 202, and a transceiver (or radio frequency (RF) unit) 203.
  • the memory 202 is connected to the processor 201 and stores various information for driving the processor 201.
  • the transceiver unit (or RF unit) 203 is connected to the processor 201 to transmit and / or receive a radio signal.
  • the processor 201 implements the proposed functions, processes and / or methods. In the above-described embodiment, the operation of the base station may be implemented by the processor 201.
  • the wireless device 100 includes a processor 101, a memory 102, and a transceiver (or RF unit) 103.
  • the memory 102 is connected to the processor 101 and stores various information for driving the processor 101.
  • the transceiver unit (or RF unit) 103 is connected to the processor 101 to transmit and / or receive a radio signal.
  • the processor 101 implements the proposed functions, processes and / or methods.
  • the processor may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices.
  • the memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and / or other storage device.
  • the RF unit may include a baseband circuit for processing a radio signal.
  • the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function.
  • the module may be stored in memory and executed by a processor.
  • the memory may be internal or external to the processor and may be coupled to the processor by various well known means.

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Abstract

La présente invention concerne un procédé permettant d'estimer un canal par un équipement utilisateur (UE). Le procédé comprend les étapes consistant à: déterminer un mode de transmission à utiliser pour recevoir des données, sur la base d'informations d'antenne comprises dans des informations de configuration sur une ressource radio; déterminer, sur la base du mode de transmission déterminé, si les informations de configuration sur un premier signal de référence peuvent ou non être déviées vers un second signal de référence; et reconnaître, s'il est déterminé que les informations de configuration sur le premier signal de référence peuvent être déviées vers le second signal de référence, le premier signal de référence étant reçu en tant que second signal de référence et effectuer une estimation de canal en utilisant le second signal de référence reconnu.
PCT/KR2017/001586 2016-03-14 2017-02-14 Procédé d'estimation de canal de commande et équipement utilisateur pour le mettre en œuvre Ceased WO2017159995A1 (fr)

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