WO2014157073A1 - 基地局、プロセッサ、及び通信制御方法 - Google Patents
基地局、プロセッサ、及び通信制御方法 Download PDFInfo
- Publication number
- WO2014157073A1 WO2014157073A1 PCT/JP2014/058056 JP2014058056W WO2014157073A1 WO 2014157073 A1 WO2014157073 A1 WO 2014157073A1 JP 2014058056 W JP2014058056 W JP 2014058056W WO 2014157073 A1 WO2014157073 A1 WO 2014157073A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cell
- reference signal
- specific reference
- user terminals
- base station
- Prior art date
Links
Images
Classifications
-
- 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
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
- H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
-
- 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
Definitions
- the present invention relates to a base station, a processor, and a communication control method used in a mobile communication system.
- Non-Patent Document 1 As one of the new carrier structures, it has been studied to reduce the cell-specific reference signal (CRS) as compared with the conventional carrier structure (for example, see Non-Patent Document 1). Thereby, since the radio
- CRS cell-specific reference signal
- the user terminal that establishes connection with the cell performs downlink channel state measurement by receiving the cell-specific reference signal transmitted in the cell.
- a conventional user terminal (low-capacity user terminal) that does not support the new carrier structure may not be able to perform normal channel state measurement. is there.
- the present invention provides a base station, a processor, and a communication control method that can introduce a new carrier structure while ensuring backward compatibility.
- the base station manages cells in a mobile communication system.
- the base station receives information indicating the communication capability of the terminal from each of a transmission unit that transmits a cell-specific reference signal used for downlink channel state measurement and a plurality of user terminals connected to the cell.
- a receiving unit and a control unit that controls transmission of the cell-specific reference signal based on each communication capability of the plurality of user terminals.
- FIG. 1 is a configuration diagram of an LTE system according to the embodiment.
- FIG. 2 is a block diagram of the UE according to the embodiment.
- FIG. 3 is a block diagram of the eNB according to the embodiment.
- FIG. 4 is a protocol stack diagram of a radio interface in the LTE system.
- FIG. 5 is a configuration diagram of a radio frame used in the LTE system.
- FIG. 6 is a frame configuration diagram showing an arrangement example of cell-specific reference signals (CRS) in a carrier.
- FIG. 7 is a diagram illustrating an arrangement example of CRSs in one subframe and one resource block.
- FIG. 8 is a diagram illustrating an operating environment according to the embodiment.
- FIG. 9 is an operation flowchart of the eNB according to the embodiment.
- FIG. 10 is a diagram for explaining a specific example of CRS transmission according to the embodiment.
- the base station manages cells in a mobile communication system.
- the base station receives information indicating the communication capability of the terminal from each of a transmission unit that transmits a cell-specific reference signal used for downlink channel state measurement and a plurality of user terminals connected to the cell.
- the control unit transmits the cell-specific reference signal. Controls partial transmission.
- the cell-specific reference signal is also used for downlink received power measurement.
- the transmission unit includes a plurality of transmission antennas.
- the control unit When the low-capacity user terminals are included in the plurality of user terminals, the control unit generally transmits the cell-specific reference signal from one transmission antenna among the plurality of transmission antennas for the reception power measurement. While transmitting, control is performed to partially transmit the cell-specific reference signal from each of the remaining transmitting antennas.
- control unit performs control to stop transmission of the cell-specific reference signal when the low-capacity user terminals are not included in the plurality of user terminals.
- the cell-specific reference signal is also used for downlink received power measurement.
- the transmission unit includes a plurality of transmission antennas.
- the control unit transmits the cell-specific reference signal from one of the plurality of transmission antennas for the reception power measurement. While continuing, control is performed to stop transmission of the cell-specific reference signal from each of the remaining transmission antennas.
- the control unit when the low-capacity user terminal is included in the plurality of user terminals, the control unit performs periodic reporting as a report to the base station of channel state information obtained by the channel state measurement. Without setting the low-capacity user terminal, an aperiodic report is set for the low-capacity user terminal.
- control unit performs the channel state measurement for reporting the channel state information at a transmission timing of the cell-specific reference signal when the plurality of user terminals include the low capability user terminal. Control the timing of the channel state measurement in the low-capacity user terminal to do so.
- the control unit can decode the downlink data by using the cell-specific reference signal.
- a radio resource including the cell-specific reference signal is allocated to the low capability user terminal.
- control unit includes the cell-specific reference when the plurality of user terminals further include a high-capacity user terminal capable of performing the channel state measurement without receiving the cell-specific reference signal. Control is performed to notify the high-capacity user terminal of information indicating a radio resource including a signal.
- the processor according to the embodiment is provided in a base station that manages cells in a mobile communication system.
- the processor transmits a cell-specific reference signal used for downlink channel state measurement, and receives information indicating the communication capability of the terminal from each of a plurality of user terminals connected to the cell. And processing for controlling transmission of the cell-specific reference signal based on the communication capabilities of the plurality of user terminals.
- the communication control method is used for a base station that manages cells in a mobile communication system.
- the communication control method receives a cell-specific reference signal used for downlink channel state measurement and receives information indicating the communication capability of the terminal from each of a plurality of user terminals connected to the cell. And a step of controlling transmission of the cell-specific reference signal based on each communication capability of the plurality of user terminals.
- FIG. 1 is a configuration diagram of an LTE system according to the present embodiment.
- the LTE system includes a plurality of UEs (User Equipment) 100, an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) 10, and an EPC (Evolved Packet Core) 20.
- the E-UTRAN 10 corresponds to a radio access network
- the EPC 20 corresponds to a core network.
- the E-UTRAN 10 and the EPC 20 constitute an LTE system network.
- the UE 100 is a mobile communication device and performs wireless communication with a serving cell.
- UE100 is corresponded to a user terminal.
- the E-UTRAN 10 includes a plurality of eNBs 200 (evolved Node-B).
- the eNB 200 corresponds to a base station.
- Each eNB 200 manages one or a plurality of cells and performs radio communication with the UE 100 that has established a connection with the own cell.
- “cell” is used as a term indicating a minimum unit of a radio communication area, and is also used as a term indicating a function of performing radio communication with the UE 100.
- the eNB 200 has, for example, a radio resource management (RRM) function, a user data routing function, and a measurement control function for mobility control and scheduling.
- RRM radio resource management
- the EPC 20 includes a plurality of MME (Mobility Management Entity) / S-GW (Serving-Gateway) 300.
- MME Mobility Management Entity
- S-GW Serving-Gateway
- the MME is a network node that performs various types of mobility control for the UE 100, and corresponds to a control station.
- the S-GW is a network node that performs transfer control of user data, and corresponds to an exchange.
- the EPC 20 configured by the MME / S-GW 300 accommodates the eNB 200.
- the eNB 200 is connected to each other via the X2 interface.
- the eNB 200 is connected to the MME / S-GW 300 via the S1 interface.
- FIG. 2 is a block diagram of the UE 100.
- the UE 100 includes a plurality of antennas 101, a radio transceiver 110, a user interface 120, a GNSS (Global Navigation Satellite System) receiver 130, a battery 140, a memory 150, a processor 160, Have.
- the memory 150 and the processor 160 constitute a control unit.
- the UE 100 may not have the GNSS receiver 130.
- the memory 150 may be integrated with the processor 160, and this set (that is, a chip set) may be used as the processor 160 '.
- the plurality of antennas 101 and the wireless transceiver 110 are used for transmitting and receiving wireless signals.
- the radio transceiver 110 converts the baseband signal output from the processor 160 into a radio signal and transmits it from the plurality of antennas 101. Further, the radio transceiver 110 converts radio signals received by the plurality of antennas 101 into baseband signals and outputs them to the processor 160.
- the user interface 120 is an interface with a user who owns the UE 100, and includes, for example, a display, a microphone, a speaker, and various buttons.
- the user interface 120 receives an operation from the user and outputs a signal indicating the content of the operation to the processor 160.
- the GNSS receiver 130 receives a GNSS signal and outputs the received signal to the processor 160 in order to obtain location information indicating the geographical location of the UE 100.
- the battery 140 stores power to be supplied to each block of the UE 100.
- the memory 150 stores a program executed by the processor 160 and information used for processing by the processor 160.
- the processor 160 includes a baseband processor that modulates / demodulates and encodes / decodes a baseband signal, and a CPU (Central Processing Unit) that executes various programs by executing a program stored in the memory 150.
- the processor 160 may further include a codec that performs encoding / decoding of an audio / video signal.
- the processor 160 executes various controls and various communication protocols described later.
- FIG. 3 is a block diagram of the eNB 200.
- the eNB 200 includes a plurality of antennas 201, a radio transceiver 210, a network interface 220, a memory 230, and a processor 240.
- the memory 230 and the processor 240 constitute a control unit.
- the plurality of antennas 201 and the wireless transceiver 210 are used for transmitting and receiving wireless signals.
- the radio transceiver 210 converts the baseband signal output from the processor 240 into a radio signal and transmits it from the plurality of antennas 201.
- the plurality of antennas 201 and the wireless transceiver 210 constitute a transmission unit and a reception unit.
- the radio transceiver 210 converts radio signals received by the plurality of antennas 201 into baseband signals and outputs them to the processor 240.
- the network interface 220 is connected to the neighboring eNB 200 via the X2 interface and is connected to the MME / S-GW 300 via the S1 interface.
- the network interface 220 is used for communication performed on the X2 interface and communication performed on the S1 interface.
- the memory 230 stores a program executed by the processor 240 and information used for processing by the processor 240.
- the processor 240 includes a baseband processor that performs modulation / demodulation and encoding / decoding of a baseband signal, and a CPU that executes a program stored in the memory 230 and performs various controls.
- the processor 240 executes various controls and various communication protocols described later.
- FIG. 4 is a protocol stack diagram of a radio interface in the LTE system. As shown in FIG. 4, the radio interface protocol is divided into layers 1 to 3 of the OSI reference model, and layer 1 is a physical (PHY) layer. Layer 2 includes a MAC (Media Access Control) layer, an RLC (Radio Link Control) layer, and a PDCP (Packet Data Convergence Protocol) layer. Layer 3 includes an RRC (Radio Resource Control) layer.
- PHY Physical
- Layer 2 includes a MAC (Media Access Control) layer, an RLC (Radio Link Control) layer, and a PDCP (Packet Data Convergence Protocol) layer.
- Layer 3 includes an RRC (Radio Resource Control) layer.
- RRC Radio Resource Control
- the physical layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data is transmitted between the physical layer of the UE 100 and the physical layer of the eNB 200 via a physical channel.
- the MAC layer performs data priority control, retransmission processing by hybrid ARQ (HARQ), and the like. Data is transmitted via the transport channel between the MAC layer of the UE 100 and the MAC layer of the eNB 200.
- the MAC layer of the eNB 200 includes a scheduler that determines uplink / downlink transport formats (transport block size, modulation / coding scheme (MCS)) and allocated resource blocks.
- MCS modulation / coding scheme
- the RLC layer transmits data to the RLC layer on the receiving side using the functions of the MAC layer and the physical layer. Data is transmitted between the RLC layer of the UE 100 and the RLC layer of the eNB 200 via a logical channel.
- the PDCP layer performs header compression / decompression and encryption / decryption.
- the RRC layer is defined only in the control plane. Control messages (RRC messages) for various settings are transmitted between the RRC layer of the UE 100 and the RRC layer of the eNB 200.
- the RRC layer controls the logical channel, the transport channel, and the physical channel according to establishment, re-establishment, and release of the radio bearer.
- RRC connected state When there is an RRC connection between the RRC of the UE 100 and the RRC of the eNB 200, the UE 100 is in a connected state (RRC connected state). Otherwise, the UE 100 is in an idle state (RRC idle state).
- the NAS (Non-Access Stratum) layer located above the RRC layer performs session management and mobility management.
- FIG. 5 is a configuration diagram of a radio frame used in the LTE system.
- OFDMA Orthogonal Frequency Division Multiplexing Access
- SC-FDMA Single Carrier Frequency Multiple Access
- the radio frame is composed of 10 subframes arranged in the time direction, and each subframe is composed of two slots arranged in the time direction.
- the length of each subframe is 1 ms, and the length of each slot is 0.5 ms.
- Each subframe includes a plurality of resource blocks (RB) in the frequency direction and includes a plurality of symbols in the time direction.
- a guard interval called a cyclic prefix (CP) is provided at the head of each symbol.
- the resource block includes a plurality of subcarriers in the frequency direction.
- a radio resource unit composed of one symbol and one subcarrier is referred to as a resource element (RE).
- RE resource element
- frequency resources can be specified by resource blocks, and time resources can be specified by subframes (or slots).
- the section of the first few symbols of each subframe is a control region used mainly as a physical downlink control channel (PDCCH) for transmitting a control signal.
- the remaining section of each subframe is an area that can be used as a physical downlink shared channel (PDSCH) mainly for transmitting user data.
- PDSCH physical downlink shared channel
- the PDCCH carries a control signal.
- the control signal includes, for example, uplink SI (Scheduling Information), downlink SI, and TPC bits.
- the uplink SI is information indicating allocation of uplink radio resources
- the downlink SI is information indicating allocation of downlink radio resources.
- the TPC bit is information instructing increase / decrease in uplink transmission power. These pieces of information are referred to as downlink control information (DCI).
- DCI downlink control information
- the PDSCH carries control signals and / or user data.
- the downlink data area may be allocated only to user data, or may be allocated such that user data and control signals are multiplexed.
- both ends in the frequency direction in each subframe are control regions mainly used as a physical uplink control channel (PUCCH) for transmitting a control signal.
- the central portion in the frequency direction in each subframe is an area that can be used as a physical uplink shared channel (PUSCH) mainly for transmitting user data.
- PUSCH physical uplink shared channel
- PUCCH carries a control signal.
- the control signal includes, for example, CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indicator), SR (Scheduling Request), ACK / NACK, and the like.
- CQI is information indicating downlink channel quality, and is used for determining a recommended modulation scheme and coding rate to be used for downlink transmission.
- PMI is information indicating a precoder matrix that is preferably used for downlink transmission.
- the RI is information indicating the number of layers (number of streams) that can be used for downlink transmission.
- SR is information for requesting allocation of uplink radio resources (resource blocks).
- ACK / NACK is information indicating whether or not a signal transmitted via a downlink physical channel (for example, PDSCH) has been successfully decoded.
- the PUSCH carries control signals and / or user data.
- the uplink data area may be allocated only to user data, or may be allocated such that user data and control signals are multiplexed.
- a cell-specific reference signal (CRS) and a channel state information reference signal (CSI-RS) are distributed and provided in each subframe in the carrier.
- CRS and CSI-RS is configured by a predetermined orthogonal signal sequence, and is provided in a predetermined resource element.
- the eNB 200 transmits CRS and CSI-RS from each of the plurality of antennas 201.
- CRS can transmit a maximum of 4 antennas, but CSI-RS can transmit a maximum of 8 antennas.
- FIG. 6 is a frame configuration diagram showing an example of CRS arrangement in the current specification.
- CRSs are distributed in the time axis direction and the frequency axis direction. Specifically, the CRS is provided in all subframes in the time axis direction. The CRS is provided in all resource blocks (RB) in the frequency axis direction.
- RB resource blocks
- the CSI-RS is provided with a long cycle of once in a plurality of subframes.
- FIG. 7 is a diagram illustrating an arrangement example of CRSs in one subframe and one resource block. As shown in FIG. 7, four resource elements (RE) are provided as reference signal resources in each of the first half slot and the second half slot in one subframe (subframe N), and a total of eight resource elements are provided. It is provided as a reference signal resource.
- RE resource elements
- UE100 performs channel state measurement and received power (RSRP; Reference Signal Received Power) measurement using these reference signals.
- RSRP Reference Signal Received Power
- Channel state measurement is a process for measuring channel characteristics.
- UE100 measures a channel characteristic for every combination of each transmitting antenna of eNB200, and each receiving antenna of UE100.
- the UE 100 performs decoding of downlink data and reporting of channel state information (CSI) based on the channel characteristics obtained by channel state measurement.
- CSI includes CQI, PMI, and RI.
- the process in which UE 100 reports CSI to eNB 200 based on CRS and / or CSI-RS is also referred to as “CSI feedback”.
- RSRP measurement is a process of measuring RSRP indicating CRS received power.
- UE100 measures RSRP about CRS of one transmission antenna of eNB200, and uses measured RSRP for mobility control (cell reselection control, handover control), etc.
- CRS is a reference signal introduced in 3GPP Release 8 (hereinafter referred to as “Rel. 8”).
- Rel. 8 is the first release of LTE.
- the UE 100 conforming to the release after 8 can use the CRS, that is, all UEs 100 conforming to LTE.
- CSI-RS is a reference signal introduced in 3GPP Release 10 (hereinafter referred to as “Rel. 10”). Rel. The UE 100 conforming to the release after 10 can use CSI-RS. However, Rel. The UE 100 based on 8 cannot use CSI-RS because its capability is limited.
- the UE 100 (low-capacity UE) conforming to FIG. 8 cannot perform channel state measurement without receiving CRS.
- a UE 100 (high-capacity UE) conforming to a release after 10 can perform channel state measurement using CSI-RS without receiving a CRS.
- Rel. 8 conforming to UE 8
- Rel. None of the UEs 100 conforming to the release after 10 can perform RSRP measurement without receiving the CRS.
- NCT New Carrier Type
- FIG. 8 is a diagram showing an operating environment according to the present embodiment. As shown in FIG. 8, each of the plurality of UEs 100 (UEs 100-1 to 100-n) is in a connected state in a cell managed by the eNB 200. The plurality of UEs 100 in the cell of the eNB 200 includes various releases of the UEs 100.
- ENB200 receives the information which shows communication capability from each of several UE100 connected with an own cell.
- the communication capability is a release that the UE 100 complies with.
- Information indicating the release to which the UE 100 complies is included in, for example, “UE-EUTRA-Capability” transmitted and received in the RRC layer.
- the ENB200 controls transmission of CRS based on each release of a plurality of UEs 100 connected to its own cell.
- the eNB 200 is the Rel. 8 (hereinafter referred to as “Rel. 8 UE”) 100 partially transmits CRS when included in a plurality of UEs 100 connected to the own cell.
- “partially transmit CRS” means to transmit CRS only in some subframes in the time direction and / or to transmit CRS only in some resource blocks in the frequency direction. means.
- the eNB 200 is connected to the Rel. 8 Only when the UE 100 exists, transmits a CRS limited to necessary radio resources.
- FIG. 9 is an operation flowchart of the eNB 200 according to the present embodiment. Each step in FIG. 9 is executed by the processor 240 of the eNB 200 (with the radio transceiver 210 and the memory 230 being used together as necessary).
- step S101 the eNB 200 receives release information included in “UE-EUTRA-Capability” from each of a plurality of UEs 100 connected to its own cell.
- Step S102 the eNB 200 determines that the Rel. 8 Determine whether UE100 is included.
- step S103 the eNB 200 stops transmitting the CRS.
- the resource element provided with CRS can be used for user data transmission. Further, even if CRS transmission is stopped, CSI-RS transmission is continued, so that Rel. UE 100 compliant with 10 and later releases can perform channel state measurements.
- the eNB 200 continues to transmit CRS from one antenna 201 (for example, the antenna corresponding to antenna port # 0) among the plurality of antennas 201 for RSRP measurement, while the CRS from each remaining antenna 201 is transmitted. Set to stop transmission. Thereby, RSRP measurement can be enabled.
- step S104 the eNB 200 partially transmits the CRS.
- the eNB 200 sets the CRS to be transmitted only in some subframes in the time direction. Thereby, the resource element in which CRS was provided can be used for user data transmission.
- the eNB 200 transmits the CRS from one antenna 201 (for example, the antenna corresponding to the antenna port # 0) out of the plurality of antennas 201 for RSRP measurement, while transmitting the CRS from the remaining antennas 201. Set to send partially. Thereby, RSRP measurement can be enabled.
- step S105 the eNB 200 sends a periodic report to the eNB 200 as a report to the eNB 200 of the CSI obtained by channel state measurement. 8 Rel. 8 Set to UE100.
- Such a CSI report setting is performed by sending an RRC layer message (RRC message) from the eNB 200 to the Rel. 8 Performed by transmitting to UE100.
- RRC message RRC layer message
- Non-periodic CSI report is Rel. 8
- the UE 100 can perform channel state measurement.
- step S106 the eNB 200 determines whether the Rel.
- a radio resource including CRS hereinafter referred to as “CRS transmission radio resource”
- CCT support UE a radio resource including CRS
- the notification of the CRS transmission radio resource is performed by transmitting an RRC message from the eNB 200 to the NCT support UE 100.
- the NCT support UE 100 is a UE 100 that conforms to a release in which NCT is introduced.
- the CRS transmission radio resource is a subframe and / or resource block in which CRS is provided.
- the NCT support UE 100 can perform channel state measurement using not only CSI-RS but also CRS.
- eNB200 may abbreviate
- step S107 the eNB 200 performs scheduling of radio resources.
- eNB 200 uses Rel. 8
- the CRS transmission radio resource is set to Rel. So that the UE 100 can decode the downlink data using the CRS. 8 Assign to UE100.
- radio resources (resource blocks) included in the some subframes are set to Rel. 8 Scheduling to allocate to UE100.
- step S108 the eNB 200 assigns CRS transmission radio resources to all Rel. 8 Determine whether assigned to UE100.
- step S109 the eNB 200 determines that the Rel. 8
- the radio resource (CRS transmission radio resource) allocated to UE 100 is set to Rel. 8 Notify UE100.
- Rel. 8 Since the UE 100 can receive the downlink data using the CRS transmission radio resource, it can normally decode the downlink data.
- the eNB 200 determines whether the Rel. 8 In order for UE 100 to perform channel state measurement for CSI reporting, Rel. 8 Control the channel state measurement timing in UE100. Specifically, at the timing of the CRS transmission radio resource, the eNB 200 performs channel state measurement for CSI reporting by Rel. 8 Instruct the UE100. As a result, Rel. 8 UE100 can report CSI normally.
- step S110 the eNB 200 adds the Rel. 8 CRS is additionally transmitted in the radio resource allocated to UE100.
- the Rel. 8 Since the UE 100 can receive the downlink data using the CRS transmission radio resource, it can normally decode the downlink data.
- FIG. 10 is a diagram for explaining a specific example of CRS transmission. As shown in FIG. 8 CRS is transmitted in all resource blocks in some subframes so that the UE 100 can perform channel state measurement for CSI reporting. In addition, the eNB 200 performs channel state measurement in the partial subframe in Rel. 8 Instruct the UE100.
- eNB 200 is Rel. 8 Resource blocks included in the partial subframes are set to Rel. So that the UE 100 can perform channel state measurement for downlink data decoding. 8 Assign to UE100. However, the eNB 200 assigns resource blocks included in subframes other than the partial subframe to Rel. 8 When assigning to UE100, CRS is additionally transmitted in the resource block.
- the reduction of CSI-RS is not particularly mentioned, but a plurality of UEs 100 connected to the own cell are all Rel. 8 In the case of the UE 100, the CSI-RS transmission may be stopped.
- the present invention is not limited to the LTE system, and the present invention may be applied to a system other than the LTE system.
- a base station a processor, and a communication control method that can introduce a new carrier structure while ensuring backward compatibility.
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
実施形態に係る基地局は、移動通信システムにおいてセルを管理する。前記基地局は、下りリンクのチャネル状態測定に使用されるセル固有参照信号を送信する送信部と、前記セルと接続する複数のユーザ端末のそれぞれから、自端末の通信能力を示す情報を受信する受信部と、前記複数のユーザ端末のそれぞれの通信能力に基づいて、前記セル固有参照信号の送信を制御する制御部と、を備える。
以下、図面を参照して、3GPP規格に準拠して構成される移動通信システムの一つであるLTE(Long Term Evolution)システムに本発明を適用する場合の実施形態を説明する。
図1は、本実施形態に係るLTEシステムの構成図である。図1に示すように、LTEシステムは、複数のUE(User Equipment)100と、E-UTRAN(Evolved-UMTS Terrestrial Radio Access Network)10と、EPC(Evolved Packet Core)20と、を含む。E-UTRAN10は無線アクセスネットワークに相当し、EPC20はコアネットワークに相当する。E-UTRAN10及びEPC20は、LTEシステムのネットワークを構成する。
下りリンクにおいて、キャリア内の各サブフレームには、セル固有参照信号(CRS)及びチャネル状態情報参照信号(CSI-RS)が分散して設けられる。CRS及びCSI-RSのそれぞれは、所定の直交信号系列により構成され、かつ、所定のリソースエレメントに設けられる。eNB200は、複数のアンテナ201のそれぞれからCRS及びCSI-RSを送信する。CRSは最大で4アンテナ分の送信であるが、CSI-RSは最大で8アンテナ分の送信が可能である。
以下、本実施形態に係る動作について説明する。本実施形態は、後方互換性を確保しながら、CRSが削減された新たなキャリア構造(NCT;New Carrier Type)を導入可能とする実施形態である。
この開示の一部をなす記載及び図面はこの発明を限定するものであると理解すべきではない。この開示から当業者には様々な代替実施形態、実施例及び運用技術が明らかとなる。
Claims (11)
- 移動通信システムにおいてセルを管理する基地局であって、
下りリンクのチャネル状態測定に使用されるセル固有参照信号を送信する送信部と、
前記セルと接続する複数のユーザ端末のそれぞれから、自端末の通信能力を示す情報を受信する受信部と、
前記複数のユーザ端末のそれぞれの通信能力に基づいて、前記セル固有参照信号の送信を制御する制御部と、
を備えることを特徴とする基地局。 - 前記制御部は、前記セル固有参照信号を受信しなければ前記チャネル状態測定を行うことができない低能力ユーザ端末が前記複数のユーザ端末に含まれる場合に、前記セル固有参照信号を部分的に送信する制御を行うことを特徴とする請求項1に記載の基地局。
- 前記セル固有参照信号は、下りリンクの受信電力測定にも使用され、
前記送信部は、複数の送信アンテナを含み、
前記制御部は、前記複数のユーザ端末に前記低能力ユーザ端末が含まれる場合に、前記受信電力測定のために前記複数の送信アンテナのうち1つの送信アンテナから前記セル固有参照信号を全体的に送信しつつ、残りの各送信アンテナから前記セル固有参照信号を部分的に送信する制御を行うことを特徴とする請求項2に記載の基地局。 - 前記制御部は、前記複数のユーザ端末に前記低能力ユーザ端末が含まれない場合に、前記セル固有参照信号の送信を停止する制御を行うことを特徴とする請求項2に記載の基地局。
- 前記セル固有参照信号は、下りリンクの受信電力測定にも使用され、
前記送信部は、複数の送信アンテナを含み、
前記制御部は、前記複数のユーザ端末に前記低能力ユーザ端末が含まれない場合に、前記受信電力測定のために前記複数の送信アンテナのうち1つの送信アンテナから前記セル固有参照信号の送信を継続しつつ、残りの各送信アンテナからの前記セル固有参照信号の送信を停止する制御を行うことを特徴とする請求項4に記載の基地局。 - 前記制御部は、前記複数のユーザ端末に前記低能力ユーザ端末が含まれる場合に、前記チャネル状態測定により得られるチャネル状態情報の前記基地局への報告として、周期的な報告を前記低能力ユーザ端末に設定せずに、非周期的な報告を前記低能力ユーザ端末に設定することを特徴とする請求項2に記載の基地局。
- 前記制御部は、前記複数のユーザ端末に前記低能力ユーザ端末が含まれる場合に、前記セル固有参照信号の送信タイミングで、前記チャネル状態情報を報告するための前記チャネル状態測定を行うように、前記低能力ユーザ端末における前記チャネル状態測定のタイミングを制御することを特徴とする請求項6に記載の基地局。
- 前記制御部は、前記複数のユーザ端末に前記低能力ユーザ端末が含まれる場合に、前記低能力ユーザ端末が前記セル固有参照信号を利用して下りリンクデータを復号できるように、前記セル固有参照信号を含んだ無線リソースを前記低能力ユーザ端末に割り当てることを特徴とする請求項2に記載の基地局。
- 前記制御部は、前記セル固有参照信号を受信しなくても前記チャネル状態測定を行うことができる高能力ユーザ端末が前記複数のユーザ端末にさらに含まれる場合に、前記セル固有参照信号を含んだ無線リソースを示す情報を前記高能力ユーザ端末に通知する制御を行うことを特徴とする請求項2に記載の基地局。
- 移動通信システムにおいてセルを管理する基地局に備えられるプロセッサであって、
下りリンクのチャネル状態測定に使用されるセル固有参照信号を送信する処理と、
前記セルと接続する複数のユーザ端末のそれぞれから、自端末の通信能力を示す情報を受信する処理と、
前記複数のユーザ端末のそれぞれの通信能力に基づいて、前記セル固有参照信号の送信を制御する処理と、
を実行することを特徴とするプロセッサ。 - 移動通信システムにおいてセルを管理する基地局に用いられる通信制御方法であって、
下りリンクのチャネル状態測定に使用されるセル固有参照信号を送信するステップと、
前記セルと接続する複数のユーザ端末のそれぞれから、自端末の通信能力を示す情報を受信するステップと、
前記複数のユーザ端末のそれぞれの通信能力に基づいて、前記セル固有参照信号の送信を制御するステップと、
を含むことを特徴とする通信制御方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015508475A JP6158309B2 (ja) | 2013-03-25 | 2014-03-24 | 基地局、プロセッサ、及び通信制御方法 |
EP14776503.6A EP2981141A4 (en) | 2013-03-25 | 2014-03-24 | BASE STATION, PROCESSOR, AND COMMUNICATION CONTROL METHOD |
US14/779,139 US20160065339A1 (en) | 2013-03-25 | 2014-03-24 | Base station, processor, and communication control method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201361805011P | 2013-03-25 | 2013-03-25 | |
US61/805,011 | 2013-03-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014157073A1 true WO2014157073A1 (ja) | 2014-10-02 |
Family
ID=51624046
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2014/058056 WO2014157073A1 (ja) | 2013-03-25 | 2014-03-24 | 基地局、プロセッサ、及び通信制御方法 |
Country Status (4)
Country | Link |
---|---|
US (1) | US20160065339A1 (ja) |
EP (1) | EP2981141A4 (ja) |
JP (1) | JP6158309B2 (ja) |
WO (1) | WO2014157073A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017109551A1 (en) * | 2015-12-23 | 2017-06-29 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and apparatus for controlling channel state indicator reference signal (csi-rs) transmission |
JP2019071581A (ja) * | 2017-10-11 | 2019-05-09 | パナソニック株式会社 | 無線通信システム及び無線通信方法 |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104852778B (zh) * | 2014-02-18 | 2020-03-13 | 中兴通讯股份有限公司 | 一种开销信息传输方法,基站、终端和系统 |
JP2017184000A (ja) * | 2016-03-30 | 2017-10-05 | ソニー株式会社 | 通信装置、通信方法及びプログラム |
US10645228B2 (en) * | 2017-06-26 | 2020-05-05 | Apple Inc. | Adaptability in EVS codec to improve power efficiency |
US10715290B2 (en) * | 2017-07-14 | 2020-07-14 | Kt Corporation | Apparatus and method for beam management based on channel state indicator-reference signal |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009157167A1 (ja) * | 2008-06-23 | 2009-12-30 | パナソニック株式会社 | 無線通信基地局装置および参照信号割当方法 |
WO2011047462A2 (en) * | 2009-09-21 | 2011-04-28 | Nortel Networks Limited | Reference signal design for downlink high-order mimo |
WO2012067221A1 (ja) * | 2010-11-18 | 2012-05-24 | 株式会社エヌ・ティ・ティ・ドコモ | 移動通信方法及び無線基地局 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103650372A (zh) * | 2011-07-19 | 2014-03-19 | 美国博通公司 | 用于针对分段载波提供信道状态信息(csi)测量和报告的方法和装置 |
US8983391B2 (en) * | 2011-08-12 | 2015-03-17 | Sharp Kabushiki Kaisha | Signaling power allocation parameters for uplink coordinated multipoint (CoMP) |
US9749029B2 (en) * | 2011-10-11 | 2017-08-29 | Lg Electronics Inc. | Method for measuring state of channel quality in wireless communication system including cells formed with a plurality of network nodes, and apparatus therefor |
-
2014
- 2014-03-24 WO PCT/JP2014/058056 patent/WO2014157073A1/ja active Application Filing
- 2014-03-24 EP EP14776503.6A patent/EP2981141A4/en not_active Withdrawn
- 2014-03-24 JP JP2015508475A patent/JP6158309B2/ja active Active
- 2014-03-24 US US14/779,139 patent/US20160065339A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009157167A1 (ja) * | 2008-06-23 | 2009-12-30 | パナソニック株式会社 | 無線通信基地局装置および参照信号割当方法 |
WO2011047462A2 (en) * | 2009-09-21 | 2011-04-28 | Nortel Networks Limited | Reference signal design for downlink high-order mimo |
WO2012067221A1 (ja) * | 2010-11-18 | 2012-05-24 | 株式会社エヌ・ティ・ティ・ドコモ | 移動通信方法及び無線基地局 |
Non-Patent Citations (2)
Title |
---|
NTT DOCOMO ET AL.: "CSI RS Configuration to Support 4 Tx MIMO UE in 8 Tx Networks", 3GPP TSG-RAN WG1#64 R1-110861, 25 February 2011 (2011-02-25), XP050490630 * |
See also references of EP2981141A4 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017109551A1 (en) * | 2015-12-23 | 2017-06-29 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and apparatus for controlling channel state indicator reference signal (csi-rs) transmission |
JP2019071581A (ja) * | 2017-10-11 | 2019-05-09 | パナソニック株式会社 | 無線通信システム及び無線通信方法 |
Also Published As
Publication number | Publication date |
---|---|
EP2981141A4 (en) | 2016-12-14 |
EP2981141A1 (en) | 2016-02-03 |
JP6158309B2 (ja) | 2017-07-05 |
US20160065339A1 (en) | 2016-03-03 |
JPWO2014157073A1 (ja) | 2017-02-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11129183B2 (en) | Method and apparatus for transmitting downlink control channel information in carrier aggregation system | |
JP6805128B2 (ja) | ユーザ端末及び基地局 | |
JP6147843B2 (ja) | 基地局及び通信制御方法 | |
JP6143524B2 (ja) | 移動通信システム、無線基地局及びユーザ端末 | |
JP6158309B2 (ja) | 基地局、プロセッサ、及び通信制御方法 | |
WO2013176027A1 (ja) | 通信システム、基地局装置、移動局装置、測定方法、および集積回路 | |
JP6306006B2 (ja) | ネットワーク装置及びユーザ端末 | |
WO2015046269A1 (ja) | ユーザ端末、基地局、及びプロセッサ | |
JP6352280B2 (ja) | ネットワーク装置及びユーザ端末 | |
WO2015046270A1 (ja) | ユーザ端末、基地局、及びプロセッサ | |
WO2018030228A1 (ja) | 移動通信方法、基地局及びユーザ端末 | |
WO2016167211A1 (ja) | 通信装置 | |
WO2014208559A1 (ja) | 通信制御方法、基地局及びユーザ端末 | |
JP6101544B2 (ja) | 基地局、通信制御方法、及びプロセッサ | |
JP6134220B2 (ja) | 基地局及びプロセッサ | |
US9888447B2 (en) | Base station | |
JP6034956B2 (ja) | 移動通信システム、基地局及びユーザ端末 | |
WO2014073488A1 (ja) | 移動通信システム、ユーザ端末、及びプロセッサ | |
WO2015046101A1 (ja) | ユーザ端末、プロセッサ、及び通信制御方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 14776503 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2015508475 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14779139 Country of ref document: US |
|
REEP | Request for entry into the european phase |
Ref document number: 2014776503 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2014776503 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |