WO2014045755A1 - Système de communication sans fil, terminal d'utilisateur, station de base sans fil, et procédé de communication sans fil - Google Patents

Système de communication sans fil, terminal d'utilisateur, station de base sans fil, et procédé de communication sans fil Download PDF

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Publication number
WO2014045755A1
WO2014045755A1 PCT/JP2013/071601 JP2013071601W WO2014045755A1 WO 2014045755 A1 WO2014045755 A1 WO 2014045755A1 JP 2013071601 W JP2013071601 W JP 2013071601W WO 2014045755 A1 WO2014045755 A1 WO 2014045755A1
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Prior art keywords
user terminal
reference signal
signaling information
signal
pseudo
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PCT/JP2013/071601
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English (en)
Japanese (ja)
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聡 永田
佑一 柿島
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株式会社エヌ・ティ・ティ・ドコモ
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/022—Site diversity; Macro-diversity
    • H04B7/024—Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
    • 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
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • 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
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
    • 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
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H04L27/26136—Pilot sequence conveying additional information
    • 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
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0014—Three-dimensional division
    • H04L5/0023—Time-frequency-space
    • 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
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0032—Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
    • H04L5/0035—Resource allocation in a cooperative multipoint environment

Definitions

  • the present invention relates to a radio communication system, a radio base station, a user terminal, and a radio communication method applicable to a cellular system or the like.
  • Non-patent Document 1 In the UMTS (Universal Mobile Telecommunications System) network, WSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Packet Access) are adopted for the purpose of improving frequency utilization efficiency and data rate.
  • the system features based on CDMA (Wideband-Code Division Multiple Access) are being extracted to the maximum.
  • LTE Long Term Evolution
  • Non-patent Document 1 LTE (Long Term Evolution) has been studied for the purpose of further high data rate and low delay.
  • the third generation system can achieve a maximum transmission rate of about 2 Mbps on the downlink using generally a fixed bandwidth of 5 MHz.
  • a maximum transmission rate of about 300 Mbps on the downlink and about 75 Mbps on the uplink can be realized using a variable band of 1.4 MHz to 20 MHz.
  • LTE-A LTE Advanced
  • inter-cell orthogonalization is one promising technique for further improving the system performance over the LTE system.
  • orthogonalization within a cell is realized by orthogonal multi-access for both uplink and downlink. That is, in the downlink, orthogonalization is performed between user terminals UE (User Equipment) in the frequency domain.
  • UE User Equipment
  • W-CDMA Wideband Code Division Multiple Access
  • CoMP coordinated multi-point transmission / reception
  • a plurality of cells perform transmission / reception signal processing in cooperation with one or a plurality of user terminals UE.
  • simultaneous transmission of multiple cells to which precoding is applied, cooperative scheduling / beamforming, and the like are being studied.
  • Application of these CoMP transmission / reception techniques is expected to improve the throughput characteristics of the user terminal UE located particularly at the cell edge.
  • the user terminal may have performed the reception process assuming that the downlink signal is transmitted from a single radio base station.
  • downlink signals may be transmitted from a plurality of transmission points with the introduction of the above-described CoMP technology or the like.
  • the present invention has been made in view of such a point, and even when a downlink signal is transmitted from a plurality of transmission points to a user terminal, a radio communication system and a radio base station that can suppress a decrease in reception accuracy
  • An object is to provide a user terminal and a wireless communication method.
  • a radio communication system of the present invention is a radio communication system comprising a plurality of radio base stations and a user terminal configured to be able to communicate with the plurality of radio base stations, wherein the radio base station is a user terminal
  • a generation unit that generates a reference signal using a pseudo-random sequence using signaling information to be notified to, and a transmission unit that transmits a downlink signal including the reference signal to a user terminal, the user terminal,
  • a determination unit configured to determine a relationship between downlink signals based on signaling information notified to a pseudo-random sequence of a reference signal; a signal processing unit configured to perform signal processing based on the relationship between the downlink signals; It is characterized by having.
  • the present invention it is possible to suppress a decrease in reception accuracy even when downlink signals are transmitted from a plurality of transmission points to a user terminal.
  • Downlink CoMP transmission includes Coordinated Scheduling / Coordinated Beamforming and Joint processing.
  • Coordinated Scheduling / Coordinated Beamforming is a method for transmitting a shared data channel from only one cell to one user terminal UE, and in the frequency / space domain considering interference from other cells and interference to other cells. Assign radio resources.
  • Joint processing is a method of transmitting a shared data channel from a plurality of cells simultaneously by applying precoding, and is a Joint Transmission (JT) that transmits a shared data channel from a plurality of cells to one user terminal UE.
  • DPS Dynamic Point Selection
  • the environment to which CoMP transmission / reception is applied includes, for example, a configuration including a plurality of remote radio devices (RRE: Remote Radio Equipment) connected to a radio base station (radio base station eNB) via an optical fiber (RRE configuration) Based control) and a configuration of a radio base station (radio base station eNB) (autonomous distributed control based on an independent base station configuration).
  • RRE Remote Radio Equipment
  • the remote radio apparatus RRE is controlled centrally by the radio base station eNB.
  • an optical fiber is used between a radio base station eNB (central base station) that performs baseband signal processing and control of a plurality of remote radio apparatuses RRE and each cell (that is, each remote radio apparatus RRE).
  • connection is performed using a band signal
  • radio resource control between cells can be performed collectively in a centralized base station. Therefore, in the RRE configuration, a method using high-speed signal processing between cells such as simultaneous transmission of a plurality of cells can be applied in the downlink.
  • the transmission power of the remote radio apparatus RRE is approximately the same as the transmission power of the radio base station (macro base station) eNB (high transmission power RRE).
  • an overlay type network environment (heterogeneous environment) in which a plurality of remote radio apparatuses RRE are arranged in a cover area of a radio base station (macro base station) eNB.
  • the cell of the macro base station eNB and the cell of the remote radio apparatus RRE are different, that is, the cell identification information (cell ID) of the macro base station eNB and the cell ID of the remote radio apparatus RRE are different (first 1 heterogeneous environment) and the cell of the macro base station eNB and the cell of the remote radio apparatus RRE are the same, that is, the environment where the cell ID of the macro base station eNB and the cell ID of the remote radio apparatus RRE are the same (second Heterogeneous environment).
  • the transmission power of the remote radio apparatus RRE is lower than the transmission power of the radio base station (macro base station) eNB (low transmission power RRE).
  • downlink signals (downlink control signals, downlink data signals, synchronization signals, reference signals, etc.) are transmitted from a plurality of transmission points to the user terminal.
  • the user terminal receives a reference signal (for example, a cell-specific reference signal (CRS), a demodulation reference signal (DM-RS), a channel state measurement reference signal (CSI-RS), etc.) included in the downlink signal.
  • a reference signal for example, a cell-specific reference signal (CRS), a demodulation reference signal (DM-RS), a channel state measurement reference signal (CSI-RS), etc.
  • the user terminal performs signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing as reception processing.
  • CSI feedback information
  • each downlink signal may differ in the user terminal (FIGS. 3A and 3B). reference).
  • the user terminal cannot grasp from which transmission point each received downlink signal (for example, a reference signal assigned to a different antenna port (AP: Antenna Port)) is transmitted. And when channel estimation, a demodulation process, etc. are performed using all the reference signals which the user terminal received, there exists a possibility that reception accuracy may fall.
  • AP Antenna Port
  • the user terminal when receiving processing is performed using a reference signal transmitted from each transmission point, the user terminal considers the geographical position of each transmission point (propagation characteristics of a downlink signal transmitted from each transmission point). It is desirable to perform reception processing. Therefore, the present inventors define the case where the long-term propagation path characteristics are the same between different antenna ports (AP) as “Quasi co-location” (geographically the same), and the Quasi co-location is defined as “Quasi co-location”. The idea is that the user terminal performs different reception processes depending on whether the case is assumed or not.
  • the long-term propagation path characteristics include delay spread, Doppler spread, frequency shift, average received power, received timing, etc. Is assumed to be a Quasi co-location if some or all of them are identical. In other words, “Quasi co-location” corresponds to a geographically identical case, but is not necessarily limited to a physical proximity.
  • reception processing for example, signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing
  • CSI feedback information
  • a CRS is transmitted from an AP that is determined to be geographically identical (Quasi co-location), and CSI is transmitted from AP # 15 and AP # 16 that are determined to be geographically separated (not Quasi co-location).
  • the user terminal performs measurement processing using CRS as in the conventional case.
  • the user terminal performs independent channel estimation for AP # 15 and AP # 16, and then generates and feeds back channel quality information.
  • the assumptions as to whether or not the Quasi co-location is between different APs include, for example, PSS / SSS, CRS, DM-RS (for PDSCH), DM-RS (for ePDCCH), CSI -RS etc. are mentioned.
  • the present inventors explicitly notify from the radio base station (explicit), or implicitly notify from the radio base station.
  • the idea was to apply the method (implicit).
  • a pseudo-random sequence (scrambled) of a reference signal (DM-RS, CSI-RS, etc.) is used as a criterion for determining whether or not the user terminal is in a quasi co-location.
  • the idea was to use the signaling information notified from the radio base station for the sequence.
  • the radio base station generates a reference signal using a pseudo-random sequence using signaling information notified to the user terminal, and the user terminal transmits each downlink based on the signaling information.
  • a relationship between link signals (whether or not the signal is transmitted from a transmission point of Quasi co-location) is determined, and signal processing is performed based on the relationship between the downlink signals.
  • the DM-RS sequence r (m) can be defined as shown in (Formula 1) below.
  • the pseudo-random sequence c (i) included in (Equation 1) is initialized as follows (C init ).
  • signaling information X notified to the user terminal is included in the initialization pseudo-random sequence C init .
  • this pseudo-random sequence c (i) is generated using a 31-length gold sequence.
  • SCID scrambling identity
  • This SCID takes values of 0 and 1 (the beginning of each subframe).
  • the pseudo-random sequence used when generating the DM-RS sequence r (m) defines the signaling information X to be notified to the user terminal.
  • the signaling information X can be notified from the radio base station to the user terminal by higher layer signaling (for example, RRC signaling). Further, when the signaling information X is not notified from the radio base station, the user terminal can apply a cell ID (N ID cell ) as X. Rel. 10, since X is defined by a cell ID, X can also be considered as a virtual cell ID (virtual cell ID).
  • the user terminal generates a DM-RS using a pseudo-random sequence in which n ID (0) and n ID (1) notified from the radio base station are defined. Further, when n ID (0) and n ID (1) are not notified from the radio base station, the user terminal applies a cell ID (N ID cell ) as n ID (0) and n ID (1). be able to.
  • the CSI-RS sequence r l, ns (m) can be defined as shown in (Equation 3) below.
  • the pseudo-random sequence c (i) included in (Equation 3) is initialized as follows (C init ). As can be seen from this initialization pseudo-random sequence C init, signaling information X notified to the user terminal is included in the initialization pseudo-random sequence C init .
  • the signaling information X notified to the user terminal is also defined for the pseudo-random sequence used when generating the CSI-RS sequence r l, ns (m). Note that the radio base station can individually set the signaling information X in DM-RS and the signaling information X in CSI-RS, and set the same or different values to notify the user terminal.
  • the signaling information X can be notified from the radio base station to the user terminal by higher layer signaling (for example, RRC signaling).
  • the user terminal can apply a cell ID (N ID cell ) as X.
  • N ID cell a cell ID
  • X can also be considered as a virtual cell ID (virtual cell ID).
  • the reference signal sequence is not generated using the pseudo-random sequence using the cell ID, but is notified to the user terminal.
  • the reference signal sequence is not generated using the pseudo-random sequence using the cell ID, but is notified to the user terminal.
  • CoMP is applied in an environment (first heterogeneous environment) in which the cell IDs of the macro base station eNB and the remote radio apparatus RRE are different, or in an environment where both cell IDs are the same (second heterogeneous environment). It is possible to appropriately control the reference signal sequence during cell transmission.
  • each transmission point takes into account whether or not CoMP transmission is applied, CoMP transmission method (Joint Transmission, Dynamic Point Selection, etc.), user terminal position, etc. X to be notified to the terminal can be set.
  • the signaling information X for a DM-RS or CSI-RS pseudo-random sequence transmitted from a transmission point serving as a serving cell can be set to be the same as the cell ID.
  • the signaling information X for the pseudo-random sequence of each DM-RS can be set to the same value for user terminals to which CoMP is applied.
  • each downlink signal is transmitted using signaling information notified to a pseudo-random sequence of a reference signal (DM-RS or CSI-RS) transmitted from each of a plurality of transmission points by a user terminal. Judgment of the relationship (whether or not it is Quasi co-location). Then, reception processing (for example, signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing) is controlled based on the relationship between the downlink signals.
  • reception processing for example, signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing
  • CSI feedback information
  • the user terminal includes signaling information X (hereinafter also simply referred to as “signaling information X”) notified to the DM-RS pseudo-random sequence (scramble sequence) and the cell ID of the serving cell.
  • signaling information X hereinafter also simply referred to as “signaling information X”
  • the extended PDCCH indicates a control area provided to be time-division multiplexed with the PDSCH in the data area of the existing system (LTE Rel. 10). Similar to the data signal (PDSCH signal), the extended PDCCH can be demodulated based on DM-RS.
  • the user terminal determines whether the synchronization signal (PSS / SSS) and the DM-RS are signals transmitted from a transmission point with Quasi co-location, in order to determine whether the signaling information X and the cell ID of the serving cell Compare
  • the user terminal transmits a synchronization signal (PSS / SSS) and DM-RS. It is determined that Quasi is not co-located. That is, the user terminal determines that the synchronization signal and the DM-RS are signals transmitted from geographically different transmission points.
  • the user terminal compares the signaling information X with the cell ID of the serving cell in order to determine whether the CRS and DM-RS are signals transmitted from a transmission point that is a quasi co-location. If the signaling information X and the cell ID of the serving cell are different values, the user terminal determines that the CRS and DM-RS are not quasi co-located. That is, the user terminal determines that the CRS and DM-RS are signals transmitted from geographically different transmission points.
  • the user terminal uses these synchronization signals, CRS, and DM-RS to perform channel estimation, synchronization processing, and demodulation processing. If the reception process such as the above is performed, the reception accuracy is lowered. Therefore, the user terminal transmits a synchronization signal and / or a synchronization signal that is transmitted from the geographically same transmission point as the CRS (becomes Quasi co-location) or a synchronization signal that is DM-RS and Quasi co-location. And / or CRS is newly received and reception processing is performed.
  • each reception processing includes LTE. Rel. The same method as 10 can be applied.
  • the user terminal uses the signaling information X notified to the DM-RS pseudo-random sequence, the user terminal determines the relationship between the downlink signals (whether or not Quasi co-location exists) and performs signal processing. By doing so, the reception accuracy can be maintained.
  • the user terminal uses signaling information X (hereinafter also simply referred to as “signaling information X”) notified to the CSI-RS pseudo-random sequence (scramble sequence) and the cell ID of the serving cell.
  • signaling information X hereinafter also simply referred to as “signaling information X”
  • FIG. 5A and FIG. 5B the case where presence / absence of Quasi co-location is determined will be described.
  • the user terminal determines whether the synchronization signal (PSS / SSS) and the CSI-RS are signals transmitted from a transmission point that is Quasi co-location, in order to determine whether the signaling information X and the cell ID of the serving cell Compare
  • the user terminal transmits the synchronization signal (PSS / SSS) and the CSI-RS. It is determined that Quasi is not co-located. That is, the user terminal determines that the synchronization signal and the CSI-RS are signals transmitted from geographically different transmission points.
  • the user terminal compares the signaling information X with the cell ID of the serving cell in order to determine whether or not the CRS and CSI-RS are signals transmitted from a transmission point that is Quasi co-location.
  • the user terminal determines that the CRS and CSI-RS are not quasi co-located. That is, the user terminal determines that the CRS and CSI-RS are signals transmitted from geographically different transmission points.
  • the user terminal uses these synchronization signals, CRS and CSI-RS to perform channel estimation, synchronization processing, channel quality information. If reception processing such as generation is performed, the reception accuracy decreases. Therefore, the user terminal newly receives the synchronization signal and / or CSI-RS that becomes CRS and Quasi co-location, or the synchronization signal and / or CRS that becomes CSI-RS and Quasi co-location, and performs reception processing. I do.
  • the CSI-RS sequence r l, ns (m), (Equation 3) described above can be applied.
  • the user terminal uses the signaling information X notified to the CSI-RS pseudo-random sequence to determine the type of each downlink signal (whether it is Quasi co-location) or not By performing the processing, the reception accuracy can be maintained.
  • DM-RS DMSCH for PDSCH, DM-RS for ePDCCH
  • CSI-RS CSI-RS
  • the user terminal transmits the signaling information X 1 (hereinafter also simply referred to as “signaling information X 1 ”) notified to the user terminal with respect to the DM-RS pseudo-random sequence and the user with respect to the CSI-RS pseudo-random sequence.
  • Signaling information X 2 notified to the terminal (hereinafter also simply referred to as “signaling information X 2 ”) is compared.
  • the signaling information X 1 and the signaling information X 2 are different values (for example, the signaling information X 1 is “5” and the signaling information X 2 is “10”)
  • the user terminal determines that the DM-RS and the CSI-RS are It is determined that Quasi co-location is not performed. That is, the user terminal determines that the DM-RS and the CSI-RS are signals transmitted from geographically different transmission points.
  • the user terminal, DM-RS and CSI-RS is determined to be Quasi co-location. That is, the user terminal determines that the DM-RS and the CSI-RS are signals transmitted from the same geographical transmission point.
  • the user terminal When DM-RS and CSI-RS are not quasi-co-located, if the user terminal performs reception processing such as channel estimation and demodulation processing using these DM-RS and CSI-RS, reception accuracy deteriorates. Resulting in. Therefore, the user terminal newly receives DM-RS and / or CSI-RS in which the signaling information notified to the pseudo-random sequence of each reference signal is the same, and performs reception processing independently. On the other hand, when the signaling information X 1 and the signaling information X 2 have the same value, the user terminal performs reception processing such as channel estimation and demodulation processing using these DM-RS and CSI-RS.
  • the above-described (Formula 1) or (Formula 2) can be applied.
  • the CSI-RS sequence r l, ns (m) the above-described (Equation 3) can be applied.
  • the type of each downlink signal (whether or not it is Quasi co-location) is determined. Reception accuracy can be maintained by performing signal processing after determination.
  • the user terminal compares the signaling information X notified to the user terminal with respect to each pseudo-random sequence of each DM-RS in order to determine whether or not the APs having different DM-RSs are in the Quasi co-location.
  • the signaling information X notified to the pseudo-random sequences of APs with different DM-RSs (for example, AP # 7, # 8 and AP # 9, 10) is different, the user terminal can identify these DM-RSs as Quasi Judge that it is not co-located. That is, the user terminal determines that the CSI-RS (AP # 7, 8 and AP # 9, 10) of each AP is a signal transmitted from a geographically different transmission point.
  • each DM-RS is not quasi-co-located, if the user terminal performs reception processing such as channel estimation and demodulation processing using these DM-RSs, the reception processing accuracy deteriorates. Therefore, the user terminal performs channel estimation independently for each DM-RS (AP # 7, 8 and AP # 9, 10) having different signaling information X, and then performs data demodulation processing.
  • the user terminal compares the signaling information X notified to the user terminal with respect to each CSI-RS pseudo-random sequence in order to determine whether or not the APs having different CSI-RSs are Quasi co-location. To do.
  • the signaling information X differs between different APs (for example, AP # 15 and AP # 16)
  • the user terminal determines that these CSI-RSs are not quasi co-located. That is, the user terminal determines that the CSI-RS of each AP is a signal transmitted from a geographically different transmission point.
  • each CSI-RS is not quasi co-located, the reception accuracy will be improved if the user terminal performs reception processing such as channel estimation, channel state information generation (for example, CQI generation), demodulation processing, etc. using these CSI-RSs. Will fall. Therefore, the user terminal performs reception processing such as channel estimation, channel quality information generation (CSI feedback), demodulation processing, and the like independently for each CSI-RS having different signaling information X.
  • reception processing such as channel estimation, channel state information generation (for example, CQI generation), demodulation processing, etc. using these CSI-RSs. Will fall. Therefore, the user terminal performs reception processing such as channel estimation, channel quality information generation (CSI feedback), demodulation processing, and the like independently for each CSI-RS having different signaling information X.
  • the type of each downlink signal (whether or not it is Quasi co-location) is determined. Reception accuracy can be maintained by performing signal processing after determination.
  • FIG. 8 is an explanatory diagram of the system configuration of the wireless communication system according to the present embodiment.
  • This wireless communication system includes a plurality of wireless base stations and a user terminal configured to be capable of cooperative multipoint transmission / reception with the plurality of wireless base stations.
  • the radio communication system shown in FIG. 8 is a system that includes, for example, the LTE system or SUPER 3G.
  • carrier aggregation in which a plurality of fundamental frequency blocks with the system band of the LTE system as a unit is integrated is used.
  • this wireless communication system may be called IMT-Advanced or 4G.
  • the radio communication system 1 includes radio base stations 20A and 20B and a plurality of first and second user terminals 10A and 10B communicating with the radio base stations 20A and 20B. ing.
  • the radio base stations 20 ⁇ / b> A and 20 ⁇ / b> B are connected to the higher station apparatus 30, and the higher station apparatus 30 is connected to the core network 40.
  • the radio base stations 20A and 20B are connected to each other by wired connection or wireless connection.
  • the first and second user terminals 10A and 10B can communicate with the radio base stations 20A and 20B in the cells C1 and C2.
  • the upper station device 30 includes, for example, an access gateway device, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto. Note that, between cells, control of CoMP transmission is performed by a plurality of base stations as necessary.
  • RNC radio network controller
  • MME mobility management entity
  • the first and second user terminals 10A and 10B include an LTE terminal and an LTE-A terminal. In the following, the description will proceed as the first and second user terminals unless otherwise specified. For convenience of explanation, it is assumed that the first and second user terminals 10A and 10B communicate wirelessly with the radio base stations 20A and 20B, but more generally includes both user terminals and fixed terminal devices. It may be a user equipment (UE).
  • UE user equipment
  • OFDMA Orthogonal Frequency Division Multiple Access
  • SC-FDMA Single Carrier-Frequency Division Multiple Access
  • the wireless access method is not limited to this.
  • OFDMA is a multi-carrier transmission scheme that performs communication by dividing a frequency band into a plurality of narrow frequency bands (subcarriers) and mapping data to each subcarrier.
  • SC-FDMA is a single carrier transmission method that reduces interference between terminals by dividing a system band into bands each consisting of one or continuous resource blocks for each terminal, and a plurality of terminals using different bands. .
  • the downlink communication channel includes PDSCH (Physical Downlink Shared Channel) as a downlink data channel shared by the first and second user terminals 10A and 10B, and a downlink L1 / L2 control channel (PDCCH, PCFICH, PHICH) And an extended control channel (ePDCCH). Transmission data and higher control information are transmitted by the PDSCH.
  • PDSCH and PUSCH scheduling information and the like are transmitted by PDCCH (Physical Downlink Control Channel) and ePDCCH (enhanced Physical Downlink Control Channel).
  • the number of OFDM symbols used for PDCCH is transmitted by PCFICH (Physical Control Format Indicator Channel).
  • the HARQ ACK / NACK for PUSCH is transmitted by PHICH (Physical Hybrid-ARQ Indicator Channel).
  • the uplink communication channel has PUSCH (Physical Uplink Shared Channel) as an uplink data channel shared by each user terminal and PUCCH (Physical Uplink Control Channel) as an uplink control channel. Transmission data and higher control information are transmitted by this PUSCH. Further, downlink channel state information (CSI), ACK / NACK, and the like are transmitted by PUCCH.
  • PUSCH Physical Uplink Shared Channel
  • PUCCH Physical Uplink Control Channel
  • radio base stations 20A and 20B have the same configuration and will be described as the radio base station 20.
  • first and second user terminals 10A and 10B which will be described later, have the same configuration and will be described as the user terminal 10.
  • the radio base station 20 includes a transmission / reception antenna 201, an amplifier unit 202, a transmission / reception unit (notification unit) 203, a baseband signal processing unit 204, a call processing unit 205, and a transmission path interface 206.
  • Transmission data transmitted from the radio base station 20 to the user terminal via the downlink is input from the higher station apparatus 30 to the baseband signal processing unit 204 via the transmission path interface 206.
  • the downlink data channel signal is transmitted from the RCP layer, such as PDCP layer processing, transmission data division / combination, RLC (Radio Link Control) retransmission control transmission processing, and MAC (Medium Access).
  • RCP layer such as PDCP layer processing, transmission data division / combination, RLC (Radio Link Control) retransmission control transmission processing, and MAC (Medium Access).
  • Control Retransmission control, for example, HARQ transmission processing, scheduling, transmission format selection, channel coding, inverse fast Fourier transform (IFFT) processing, and precoding processing are performed.
  • transmission processing such as channel coding and inverse fast Fourier transform is performed on the signal of the physical downlink control channel that is the downlink control channel.
  • the baseband signal processing unit 204 notifies the control information for each user terminal 10 to perform radio communication with the radio base station 20 to the user terminals 10 connected to the same cell through the broadcast channel.
  • the information for communication in the cell includes, for example, system bandwidth in uplink or downlink, and root sequence identification information (Root Sequence) for generating a random access preamble signal in PRACH (Physical Random Access Channel). Index) etc. are included.
  • the transmission / reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band.
  • the amplifier unit 202 amplifies the radio frequency signal subjected to frequency conversion and outputs the amplified signal to the transmission / reception antenna 201.
  • the transmission / reception section 203 constitutes reception means for receiving an uplink signal including phase difference information and PMI between a plurality of cells, and transmission means for transmitting a downlink signal including a reference signal to a user terminal.
  • a radio frequency signal received by the transmission / reception antenna 201 is amplified by the amplifier unit 202 and frequency-converted by the transmission / reception unit 203 to be a baseband signal. And is input to the baseband signal processing unit 204.
  • the baseband signal processing unit 204 performs FFT (Fast Fourier Transform) processing, IDFT (Inverse Discrete Fourier Transform) processing, error correction decoding, and MAC retransmission control on transmission data included in the baseband signal received on the uplink. Reception processing, RLC layer, and PDCP layer reception processing are performed.
  • the decoded signal is transferred to the higher station apparatus 30 via the transmission path interface 206.
  • the call processing unit 205 performs call processing such as communication channel setting and release, state management of the radio base station 20, and radio resource management.
  • FIG. 10 is a block diagram showing a configuration of a baseband signal processing unit in the radio base station shown in FIG.
  • the baseband signal processing unit 204 includes a transmission data generation unit 2041, an RS sequence generation unit 2042, a multiplexing unit 2043, an IFFT (Inverse Fast Fourier Transform) unit 2044, and a CP (Cyclic Prefix) addition unit 2045. It is configured.
  • the transmission data generation unit 2041 performs error correction coding and interleaver on the transmission data symbol series.
  • Transmission data generation section 2041 performs error correction coding / interleaving on the transmission data, and then serial-parallel converts the transmission data sequence (n bits constituting one OFDM symbol) to generate a plurality of data signals for subcarrier modulation. Generate. Interleaving may be performed after a plurality of data signals are generated.
  • Transmission data generation section 2041 further subcarrier modulates a plurality of data signals in parallel.
  • the RS sequence generation unit 2042 generates a reference signal sequence using a pseudo-random sequence using the signaling information X notified to the user terminal.
  • the reference signal sequence is a DM-RS sequence
  • RS sequence generation section 2042 generates a DM-RS with the DM-RS sequence using the pseudo-random sequence shown in (Expression 1) or (Expression 2) above. be able to.
  • the reference signal sequence is a CSI-RS sequence
  • RS sequence generation section 2042 can generate a CSI-RS with a CSI-RS sequence using the pseudo-random sequence shown in (Equation 3) above.
  • the signaling information X for the DM-RS pseudo-random coefficient and the signaling information X for the CSI-RS pseudo-random coefficient can be notified semi-statically to the user terminal by higher layer signaling (for example, RRC signaling).
  • the RS sequence generation unit 2042 transmits the signaling information X for the pseudo-random coefficient to be notified to the user terminal, the signaling information X for the pseudo-random coefficient of the CSI-RS, whether or not CoMP transmission is applied, and the CoMP transmission scheme (Joint Transmission, Dynamic Point Selection, etc.), the position of the user terminal, etc. can be taken into consideration.
  • the multiplexing unit 2043 multiplexes the transmission data and the RS (reference signal) to the radio resource.
  • IFFT section 2044 performs inverse fast Fourier transform on a frequency domain transmission signal (subcarrier signal) in which transmission data and RS are subcarrier mapped.
  • the frequency component signal assigned to the subcarrier is converted into a time component signal sequence by inverse fast Fourier transform. Thereafter, a cyclic prefix is added by the CP adding unit 2045.
  • the user terminal 10 includes a transmission / reception antenna 101, an amplifier unit 102, a transmission / reception unit (reception unit) 103, a baseband signal processing unit 104, and an application unit 105.
  • a radio frequency signal received by the transmission / reception antenna 101 is amplified by the amplifier unit 102, frequency-converted by the transmission / reception unit 103, and converted into a baseband signal.
  • the baseband signal is subjected to FFT processing, error correction decoding, retransmission control reception processing, and the like by the baseband signal processing unit 104.
  • downlink transmission data is transferred to the application unit 105.
  • the application unit 105 performs processing related to layers higher than the physical layer and the MAC layer. Also, the broadcast information in the downlink data is also transferred to the application unit 105.
  • uplink transmission data is input from the application unit 105 to the baseband signal processing unit 104.
  • the baseband signal processing unit 104 performs mapping processing, retransmission control (HARQ) transmission processing, channel coding, DFT (Discrete Fourier Transform) processing, and IFFT processing.
  • the transmission / reception unit 103 converts the baseband signal output from the baseband signal processing unit 104 into a radio frequency band. Thereafter, the amplifier unit 102 amplifies the frequency-converted radio frequency signal and transmits it from the transmission / reception antenna 101.
  • the transmission / reception part 103 comprises the receiving means which receives a downlink signal.
  • FIG. 12 is a block diagram showing a configuration of a baseband signal processing unit in the user terminal shown in FIG.
  • the baseband signal processing unit 104 mainly includes a CP removal unit 1041, an FFT unit 1042, a separation unit 1043, a channel estimation unit 1044, a demodulation unit 1045, a feedback information generation unit 1046, and a determination unit 1047. It is configured.
  • CP removing section 1041 removes the cyclic prefix from the received signal.
  • the FFT unit 1042 performs fast Fourier transform on the received signal from which CP has been removed, and converts a time-series signal component into a sequence of frequency components.
  • Separating section 1043 performs subcarrier demapping on the received signal to separate the RS and the shared channel signal (data signal).
  • the reference signals (DM-RS, CSI-RS) are output to the determination unit 1047.
  • the determination unit 1047 determines the relationship between the downlink signals (the downlink signals are quasi co -Whether or not the signal is a signal transmitted from a transmission point that is a location.
  • downlink signals include synchronization signals (PSS / SSS), CRS, DM-RS, CSI-RS, and the like.
  • the determination unit 1047 compares the signaling information X notified to the pseudo-random coefficient of the reference signal with the cell ID of the serving cell, and performs the Quasi co-location. Make a decision.
  • the determination unit 1047 determines that the synchronization signal (PSS / SSS) or CRS and CSI-RS or DM-RS are not quasi co-located.
  • Determination unit 1047 outputs the determination result to signal processing unit 1050 including a channel estimation unit, a demodulation unit, a feedback information generation unit, and the like.
  • determination section 1047 includes signaling information X 1 notified for the pseudo-random coefficient of DM-RS and signaling information X 2 notified for the pseudo-random coefficient of DM-RS. And the quasi co-location between the DM-RS and the CSI-RS is determined. Then, the determination unit 1047 outputs the determination result to the signal processing unit 1050.
  • the determination unit 1047 notifies the user terminal of each CSI-RS pseudo-random sequence in order to determine whether or not the APs having different CSI-RSs are quasi co-location. Compare the signaling information X to be performed. Alternatively, the determination unit 1047 determines the signaling information X notified to the user terminal for each DM-RS pseudo-random sequence in order to determine whether or not the APs with different DM-RSs are quasi co-location. Compare. Then, the determination unit 1047 outputs the determination result to the signal processing unit 1050.
  • the signal processing unit 1050 performs signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing based on the relationship between the downlink signals output from the determination unit 1047.
  • the determination unit 1047 performs channel estimation, synchronization processing, demodulation processing, feedback information (CSI) generation processing, and the like independently for each downlink signal determined to be quasi co-location. That is, these processes are performed for each downlink signal having the same cell ID and signaling information X notified to the user terminal.
  • the channel estimation unit 1044 performs channel estimation using the DM-RS and CSI-RS determined by the determination unit 1047 as the quasi co-location.
  • Channel estimation section 1044 outputs the channel estimation value obtained using DM-RS to demodulation section 1045, and outputs the channel estimation value obtained using CSI-RS to feedback information generation section 1046.
  • Demodulation section 1045 demodulates the shared channel signal using the channel estimation value.
  • the feedback information generation unit 1046 generates CSI (feedback information) using the obtained channel estimation value.
  • CSI include per-cell CSI (PMI, CDI, CQI), inter-cell CSI (phase difference information, amplitude difference information), RI (Rank Indicator), and the like. These CSIs are fed back to the radio base station through PUCCH and PUSCH.
  • channel estimation section 1044, demodulation section 1045, and feedback information generation section 1046 use the same reference signal as the signaling information X notified to the user terminal in the reference signal sequence transmitted from the radio base station. It is a signal processing part which performs signal processing using it.
  • the signal processing unit is the channel estimation unit 1044 and the demodulation unit 1045.
  • the signal processing unit is the channel estimation unit 1044 and A feedback information generation unit 1046.
  • the RS sequence generation section 2042 of the radio base station generates a reference signal sequence using a pseudo-random sequence using signaling information notified to the user terminal.
  • the reference signal sequence is a DM-RS sequence
  • a DM-RS is generated with a DM-RS sequence using the pseudo-random sequence shown in (Expression 1) or (Expression 2).
  • the reference signal sequence is a CSI-RS sequence
  • a CSI-RS is generated using the CSI-RS sequence using the pseudo-random sequence shown in (Equation 3).
  • signaling information in the pseudo-random sequence of (Equation 1) to (Equation 3) is semi-statically notified to the user terminal by higher layer signaling (for example, RRC signaling).
  • the user terminal determines the type of each downlink signal (whether it is Quasi co-location) based on the signaling information X notified to the pseudo-random sequence of the reference signal, and determines the downlink signal Signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing is performed for each type.
  • the downlink signal Signal processing such as channel estimation, synchronization processing, demodulation processing, and feedback information (CSI) generation processing is performed for each type.
  • CSI feedback information

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

Abstract

Une diminution de la précision de réception est évitée même lorsque des signaux de liaison descendante sont transmis à partir d'une pluralité de points de transmission à un terminal d'utilisateur. Un système de communication sans fil est pourvu d'une pluralité de stations de base sans fil, et d'un terminal d'utilisateur configuré pour communiquer avec une pluralité de dispositifs de station de base sans fil. Les stations de base sans fil comprennent une unité de génération qui génère un signal de référence en utilisant une séquence pseudo aléatoire en utilisant des informations de signalisation qui sont notifiées au terminal d'utilisateur, et une unité de transmission qui transmet un signal de liaison descendante comprenant le signal de référence au terminal d'utilisateur. Le terminal d'utilisateur comprend une unité de détermination qui détermine le type de chaque signal de liaison descendante sur la base des informations de signalisation notifiées en relation avec la séquence pseudo aléatoire du signal de référence, et une unité de traitement de signal qui effectue un traitement de signal en fonction du type du signal de liaison descendante.
PCT/JP2013/071601 2012-09-20 2013-08-09 Système de communication sans fil, terminal d'utilisateur, station de base sans fil, et procédé de communication sans fil WO2014045755A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109804686A (zh) * 2016-08-05 2019-05-24 株式会社Ntt都科摩 用户终端以及无线通信方法
CN112997421A (zh) * 2018-11-02 2021-06-18 株式会社Ntt都科摩 用户终端以及无线通信方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020166023A1 (fr) * 2019-02-14 2020-08-20 株式会社Ｎｔｔドコモ Terminal utilisateur et procédé de communication sans fil

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6242857B2 (ja) * 2012-04-19 2017-12-06 サムスン エレクトロニクス カンパニー リミテッド 協力マルチーポイント通信システムに対する基準シンボルポートの準共存識別のための方法及び装置

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
AD-HOC CHAIRMAN (ERICSSON): "Summary of Quasi co-located Antenna Ports Session", 3GPP TSG RAN WG1 #70, R1-123968, August 2012 (2012-08-01) *
FUJITSU: "CSI-RS configuration for CSI reporting", 3GPP TSG RAN WG1 MEETING #68, R1-120761, February 2012 (2012-02-01), pages 1 - 3 *
LG ELECTRONICS: "Consideration on CSI-RS design for CoMP", 3GPP TSG RAN WG1 MEETING #68BIS, R1-121445, March 2012 (2012-03-01), pages 1 - 3 *
LG ELECTRONICS: "Discussion on quasi-co-located antenna ports", 3GPP TSG RAN WG1 MEETING #70, R1-123538, August 2012 (2012-08-01), pages 1 - 4 *
SAMSUNG: "CSI-RS Scrambling for DL CoMP", 3GPP TSG RAN WG1 #68, R1-120175, February 2012 (2012-02-01) *
SAMSUNG: "DMRS Scrambling for DL CoMP", 3GPP TSG RAN WG1 #68, R1-120174, February 2012 (2012-02-01) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109804686A (zh) * 2016-08-05 2019-05-24 株式会社Ntt都科摩 用户终端以及无线通信方法
CN109804686B (zh) * 2016-08-05 2023-06-23 株式会社Ntt都科摩 用户终端以及无线通信方法
CN112997421A (zh) * 2018-11-02 2021-06-18 株式会社Ntt都科摩 用户终端以及无线通信方法
CN112997421B (zh) * 2018-11-02 2023-08-22 株式会社Ntt都科摩 用户终端以及无线通信方法

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