[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2015099499A1 - Procédé et appareil pour émettre/recevoir un signal de découverte dans un système de communication sans fil - Google Patents

Procédé et appareil pour émettre/recevoir un signal de découverte dans un système de communication sans fil Download PDF

Info

Publication number
WO2015099499A1
WO2015099499A1 PCT/KR2014/012921 KR2014012921W WO2015099499A1 WO 2015099499 A1 WO2015099499 A1 WO 2015099499A1 KR 2014012921 W KR2014012921 W KR 2014012921W WO 2015099499 A1 WO2015099499 A1 WO 2015099499A1
Authority
WO
WIPO (PCT)
Prior art keywords
base station
signal
discovery signal
terminal
transmission
Prior art date
Application number
PCT/KR2014/012921
Other languages
English (en)
Korean (ko)
Inventor
오진영
김윤선
김영범
곽영우
Original Assignee
삼성전자 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 삼성전자 주식회사 filed Critical 삼성전자 주식회사
Publication of WO2015099499A1 publication Critical patent/WO2015099499A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/16—Discovering, processing access restriction or access information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/10—Scheduling measurement reports ; Arrangements for measurement reports

Definitions

  • the present invention relates to a cellular wireless communication system, in particular to defining a discovery signal in order to operate a given base station in a plurality of states such as an active state and a dormant state.
  • the present invention relates to a method for a terminal to search for a base station (cell search), recognize a state of the base station, obtain time / frequency synchronization of the base station, and measure the strength of a signal from the base station.
  • LTE Long Term Evolution
  • LTE-A Long Term Evolution Advanced
  • HRPD High Rate Packet Data
  • 802.16 Various mobile communication standards such as 802.16 were developed to support high speed, high quality wireless packet data transmission services.
  • the LTE system was developed to efficiently support high-speed wireless packet data transmission, and maximizes wireless system capacity by utilizing various radio access technologies.
  • the LTE-A system is an advanced wireless system of the LTE system and has improved data transmission capability compared to LTE.
  • downlink adopts orthogonal frequency division multiplexing (OFDM)
  • uplink adopts single carrier frequency division multiple access (SC-FDMA).
  • OFDM orthogonal frequency division multiplexing
  • SC-FDMA single carrier frequency division multiple access
  • 1 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource region in which data or a control channel is transmitted in downlink of LTE and LTE-A systems. 1 illustrates a mapping relationship between a downlink physical channel and a signal in a basic structure of a radio resource region.
  • the horizontal axis represents the time domain and the vertical axis represents the frequency domain.
  • OFDMMA orthogonal frequency division multiple access
  • two slots 101 are assembled to form one subframe 102 having a length of 1 ms
  • 20 slots 101, that is, ten subframes 102 are assembled to form a radio frame 103 having a length of 10 ms. do.
  • the minimum transmission unit in the frequency domain is the subcarrier 105, and the entire system transmission band 109 consists of a total of N BW subcarriers 105.
  • N BW has a value proportional to the system transmission band.
  • the basic unit of a resource in the time-frequency domain may be defined as an OFDM symbol index and a subcarrier index as a resource element (RE) 106.
  • one RB 107, 108 is composed of N symb DL x N sc RB REs 106.
  • the minimum transmission unit for data or control information is in RB units.
  • the control channel 110 includes a physical control format indicator channel (PCFICH) including an indicator indicating the N value, a physical downlink control channel (PDCCH) including uplink or downlink scheduling information, and a hybrid automatic retransmit request (HARQ).
  • a physical HARQ indicator channel (PHICH) including an ACK / NACK signal is transmitted.
  • the downlink physical channel PDSCH (Physical Downlink Shared Channel) 111 is transmitted during the remaining subframe period in which the downlink control channel 110 is not transmitted.
  • the base station transmits a reference signal (RS) for referring to the UE for measuring the downlink channel state or for demodulating the PDSCH.
  • the reference signal is also called a pilot signal.
  • RS is a cell-specific reference signal (CRS) 112 that can be jointly received by terminals in a base station, a channel status information reference signal (CSI-RS) using relatively less resources per antenna port than an antenna. 114), which is classified into a DM-RS (Demodulation Reference Signal, 113) which the terminal uses to demodulate a PDSCH scheduled to a predetermined terminal.
  • CRS cell-specific reference signal
  • CSI-RS channel status information reference signal
  • the CSI-RS 114 and the DM-RS 113 are not transmitted to some or all of the resource regions to which the CSI-RS 114 and the DM-RS 113 may be mapped, the CSI-RS 114 and the DM-RS 113 may be used for PDSCH transmission. Can be.
  • Antenna port is a logical concept, the CSI-RS 114 is defined for each antenna port is operated to measure the channel state for each antenna port. If the same CSI-RS 114 is transmitted from multiple physical antennas, the terminal cannot distinguish each physical antenna and recognizes one antenna port.
  • the CSI-RS 114 may allocate and transmit a separate location for each base station. As such, allocating time and frequency resources for CSI-RS transmission at different locations for each base station is to prevent mutual interference between CSI-RSs of different base stations.
  • the base station includes a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). ) Is sent.
  • PSS primary synchronization signal
  • SSS secondary synchronization signal
  • the base station maps the PSS and the SSS to the predetermined position in the radio frame 103 using the sequence determined as the PSS and the SSS, respectively, and repeatedly transmits them in units of radio frames.
  • FIG. 2 is a diagram illustrating a time-frequency domain mapping structure of PSS and SSS in LTE and LTE-A systems.
  • FIG. 2 illustrates specific mapping positions of PSSs and SSSs when LTE and LTE-A systems use a frequency division duplex (FDD) scheme.
  • FDD frequency division duplex
  • the PSS is transmitted in OFDM symbols # 6 201 and 203 of subframe # 0 and subframe # 5, respectively.
  • the SSS is transmitted in OFDM symbols # 5 (202, 204) of subframe # 0 and subframe # 5, respectively.
  • PSS and SSS are mapped to 6 RBs 205 in the center of the system transmission band.
  • PSS and SSS are used for the terminal to continuously track the time and frequency of the cell, the terminal detects and measures the neighbor base station from the PSS and SSS of the neighbor base station in preparation for handover to the neighbor base station It is also used to perform the task.
  • the base station may be operated in a dormant state. If the base station is in an idle state, the base station may stop the transmission and reception of some or all of the data channel, the control channel, and the RS, thereby reducing interference with neighboring base stations and reducing energy consumption of the base station. In this case, when there is a terminal requiring data communication in the base station, the base station switches to an active state again and performs transmission and reception operations of a general data channel, a control channel, and an RS.
  • the present invention provides a method and apparatus for operating a base station in a plurality of states, such as an active state and a dormant state.
  • the present invention defines a discovery signal (discovery signal), the terminal searches for the base station (cell search), recognizes the state of the base station, obtains time / frequency synchronization of the base station, the strength of the signal from the base station It provides a method and apparatus for measuring.
  • a method for receiving a discovery signal of a terminal includes: receiving discovery signal configuration information of a neighboring base station from a base station; detecting discovery signal of the neighboring base station based on the configuration information; And reporting the measurement result of the detected discovery signal to the base station.
  • the discovery signal transmission method of the base station in the wireless communication system when entering the idle state, transmitting the discovery signal setting information, in accordance with the configuration information, comprising the step of transmitting the discovery signal,
  • the discovery signal is transmitted at intervals of m subframes within a transmission interval at intervals of n radio frames.
  • the terminal receiving the discovery signal in the wireless communication system, the communication unit performing data communication and receives the discovery signal configuration information of the neighboring base station from the base station through the communication unit, based on the configuration information, the discovery of the neighboring base station And a controller configured to detect a signal and control the communication unit to report a measurement result of the detected discovery signal to the base station.
  • the base station transmitting the discovery signal
  • the communication unit for performing data communication and enters the idle state and transmits the discovery signal setting information, in accordance with the configuration information, and transmits the discovery signal
  • a control unit for controlling the communication unit so that the discovery signal is transmitted at intervals of m subframes within a transmission period at intervals of n radio frames.
  • the present invention defines a discovery signal to operate a base station in a plurality of states such as an active state and a human state, thereby mitigating interference between base stations and increasing energy efficiency of the base station. Make it work.
  • FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in which data or a control channel is transmitted in downlink of LTE and LTE-A systems.
  • FIG. 2 is a diagram illustrating a time-frequency domain mapping structure of PSS and SSS in LTE and LTE-A systems.
  • FIG. 3 is a diagram illustrating a concept of a system operation according to the present invention.
  • FIG. 4 is a view showing the interaction between the terminal and the base station according to the present invention.
  • FIG. 5 is a diagram illustrating a base station procedure according to the present invention.
  • FIG. 6 is a diagram illustrating a terminal procedure according to the present invention.
  • FIG. 7 is a diagram illustrating a discovery signal transmission time.
  • FIG. 8 is a diagram illustrating a multiplexed discovery signal on a time axis.
  • FIG. 9 is a diagram illustrating a CSI-RS signal configuration.
  • 11 is a diagram illustrating a multiplexed discovery signal on a frequency axis.
  • FIG. 12 is a diagram illustrating power control on a discovery signal.
  • FIG. 13 is a diagram illustrating a reception power of a terminal for multiplexed discovery signals.
  • 14 is a diagram illustrating power setting by discovery signal configuration.
  • 15 is a diagram illustrating a method of classifying base station state information according to a discovery signal configuration.
  • 16 is a diagram illustrating a configuration for distinguishing a PSS / SSS signal and a discovery signal.
  • FIG. 17 is a diagram illustrating a base station apparatus according to an embodiment of the present invention.
  • FIG. 18 is a diagram illustrating a terminal device according to an exemplary embodiment of the present invention.
  • the base station is a subject performing resource allocation of the terminal, and may be at least one of an eNode B, an eNB, a Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network.
  • the terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.
  • uplink means a radio link through which a terminal transmits data or a control signal to a base station
  • downlink means a radio link through which a base station transmits data or a control signal to a terminal.
  • Embodiments of the present invention can be applied to other communication systems having a similar technical background and / or channel form.
  • the embodiment of the present invention may be applied to other communication systems through some modifications within the scope of the present invention without departing from the scope of the present invention by the judgment of those skilled in the art.
  • the HSPA system may also apply a transmission / reception method according to an aspect of an embodiment of the present invention.
  • 3 is a diagram illustrating a concept of a system operation according to the present invention.
  • 3 shows an example in which pico base stations 303, 305, 307 having relatively less coverage 304, 306, 308 are disposed within coverage 302 of macro base station 301. Since the macro base station can transmit a signal with a relatively higher transmission power than the pico base station, the coverage of the macro base station is relatively larger than that of the pico base station.
  • the terminal 312 communicates with the macro base station 301
  • the terminal 309 communicates with the pico base station 307
  • the terminal 310 communicates with the pico base station 305.
  • the terminal 311 communicates with the pico base station 303.
  • the network according to the present invention operates the pico base stations 303, 305, and 307 in an idle state.
  • the macro base station in an active state, it is possible to alleviate interference between adjacent base stations and increase system energy efficiency.
  • the macro base station is kept as active as possible to support mobility of the terminal because of its relatively wide coverage. That is, the terminal 309 communicates with the macro base station 301.
  • frequencies used by the macro base station and the pico base station may be the same frequency or different frequencies.
  • the terminal may search the pico base station (303, 305, 307) in the idle state and inform the macro base station to switch the base station to the active state.
  • the idle base station may transmit a discovery signal every specific period in order for the terminal to search for the idle base station and switch to the active state as described above.
  • FIG. 4 is a view showing the interaction between the terminal and the base station according to the present invention. Specifically, FIG. 4 illustrates a series of processes in which the terminal detects a discovery signal from an idle base station and handovers to the base station.
  • the current terminal 401 connects to the base station 1 402 and performs communication, and the base station 2 403 transmits a discovery signal to support the base station discovery of the terminal 401 as a neighbor base station of the base station 1 402. Assume that
  • step 404 base station 2 403 transmits its discovery signal configuration information to base station 1 402.
  • the discovery signal configuration information may include a transmission period, a transmission time, a bandwidth, resource mapping information, sequence information, and the like of the discovery signal.
  • the base station 1 402 that has received the discovery signal configuration information transmits the received discovery signal configuration information to the terminal 401.
  • the base station 1 402 may also transmit discovery signal configuration information of the base station other than the base station 2 403 to the terminal.
  • the base station 2 403 transmits the discovery signal to the terminal 401 based on the transmitted discovery signal configuration information.
  • the terminal 401 receiving the discovery signal detects the discovery signal received from the base station 2 403 by referring to the discovery signal setting information received from the base station 1.
  • the terminal 401 obtains subframe / radioframe synchronization of the base station (or cell) from the detected discovery signal, and obtains a cell ID indicating which base station (or cell) the discovery signal is transmitted from the base station (or cell).
  • the terminal 401 measures the signal strength of the detected discovery signal.
  • the terminal 401 may transmit a measurement result of the detected discovery signal to the base station 1 402.
  • the form of transmission may be to transmit a measurement report (measurement report).
  • the measurement report includes information such as cell ID and received signal strength of one or more detected discovery signals.
  • the terminal 401 may include information on the corresponding discovery signal in the measurement report and transmit it to the base station only when the received signal strength of the discovery signal is greater than a predetermined threshold value.
  • the threshold value may be included in the discovery signal configuration information and transmitted from the base station to the terminal 401. Alternatively, the threshold may be a preset fixed value.
  • the base station 1 402 Upon receiving the measurement report, the base station 1 402 determines whether to handover the terminal 401 based on the measurement report of the terminal 401 received in step 408.
  • the base station 1 402 When the base station 1 402 includes the cell ID of the adjacent base station 2 403 in the measurement report of the terminal 401 and the received signal strength is sufficiently large, the base station 1 402 transmits the corresponding terminal 401 to the base station 2 403 in step 410. ) Transmits a 'handover preparation request' message requesting handover to BS2 403.
  • the base station 1 402 When the base station 1 402 receives the 'handover ready' message from the base station 2 403 in step 411, the base station 1 402 requests the terminal 401 to handover to the base station 2 403 in step 412. Order. In step 413, the terminal 401 performs a handover to the base station 2 403 according to the handover command of the base station 1 402.
  • FIG. 5 is a diagram illustrating a base station procedure according to the present invention. Specifically, FIG. 5 shows the procedure of the base station in the process of FIG.
  • step 501 the base station acquires discovery signal configuration information of the neighbor cell from the neighbor cell, and in step 502 informs the terminal of the discovery signal configuration information of the neighbor cell.
  • step 503 the base station acquires a measurement report on the discovery signal from the terminal and determines whether to handover the terminal in step 504. If it is determined that the terminal does not handover, the base station moves to step 503 to acquire the next measurement report of the terminal. If the base station determines to handover the terminal in step 504, the base station transmits a "handover preparation request" message to a target cell to handover the terminal in step 505.
  • the base station When the base station acquires the message 'handover ready' from the target cell from the target cell in step 506, the base station instructs the terminal to handover to the target cell in step 507. If the base station does not acquire the 'handover ready' message in step 506, the base station proceeds to step 505 and repeats the above-described handover preparation operation.
  • FIG. 6 is a diagram illustrating a terminal procedure according to the present invention.
  • FIG. 6 illustrates a procedure of a terminal in the process of FIG. 4.
  • step 601 the UE obtains discovery signal configuration information of the neighbor cell from the base station.
  • step 602 the UE detects and measures a discover signal with reference to the acquired discovery signal configuration information of the neighbor cell.
  • step 603 the UE informs the base station of a measurement report about the measured discovery signal.
  • step 604 the terminal determines whether a handover command has been received from the base station, and if the handover command is not received, the terminal moves to step 602 to repeat the discovery detection / measurement and reporting procedure. If the terminal receives the handover command in step 604, the terminal performs handover to the target cell indicated by the handover command in step 605.
  • the PSS / SSS signal used for the base station discovery and synchronization acquisition in the existing LTE / LTE-A system may be used as a discovery signal. That is, the idle base station may transmit the discovery signal at a period equal to or relatively longer than the PSS / SSS transmission period using the PSS / SSS signal being used as the discovery signal.
  • the terminal may also receive the discovery signal based on an operation previously used to receive the PSS / SSS signal, and may acquire information regarding idle base stations such as a corresponding base station ID and synchronization.
  • the discovery signal of the idle base station and the PSS / SSS of the active base station may use different sequences. have.
  • PSS / SSS signals defined in LTE / LTE-A are all transmitted using the same frequency resource region at the same location regardless of the base station. Accordingly, if one or more idle base stations transmit in the same discovery signal transmission period around the terminal, or if one or more active base stations exist in the vicinity of the terminal, the PSS / SSS signal is used. Therefore, the terminal may not receive the discovery signal correctly. In particular, when a plurality of small base stations are distributed as shown in FIG. 3, a discovery signal interference problem of adjacent base stations may occur more frequently.
  • a base station may consider a method of transmitting a discovery signal based on the PSS / SSS signal in different time domains.
  • the terminal must repeatedly perform the downlink signal reception operation for receiving the discovery signal.
  • the PSS / SSS signal defined by 6RB is used as a discovery signal
  • the discovery signal reception performance of the UE may be degraded.
  • At least one PSS / SSS signal may be repeatedly received to improve discovery signal reception performance of the terminal, but an additional time delay may occur when the terminal detects an idle base station. Since the base station discovery time delay of the terminal increases the time it takes for the idle base station to switch to the active state, the terminal and system efficiency may be reduced. Therefore, it is necessary to define a discovery signal more efficiently than the discovery signal based on the PSS / SSS signal.
  • the present invention defines a discovery signal for the terminal to more efficiently detect the idle state base station.
  • FIG. 7 is a diagram illustrating a discovery signal transmission time.
  • the discovery signal transmitted from the idle base station is set to be transmitted in the same or relatively longer period 701 as the PSS / SSS transmission period transmitted in the conventional radio frame unit as shown in FIG. 7.
  • the base station may transmit one or more discovery signals according to the period 703 in the discovery signal transmission section 702 to improve the discovery signal reception performance of the terminal.
  • the terminal may perform a cell search and a synchronization acquisition operation by performing a discovery signal reception operation in the discovery signal transmission period 701 and the transmission period 702 of the base station.
  • system performance may vary according to the discovery signal transmission period and transmission interval setting of the base station. For example, if the discovery signal transmission period of the base station is increased, the energy efficiency of the base station and the interference reduction effect due to the discovery signal are increased, but the time required for the UE to search for a cell in the idle base station is increased. . On the contrary, when the discovery signal transmission period is reduced, energy efficiency is reduced and interference effects between neighboring cells are increased due to frequent discovery signal transmission of the base station, but the time required for cell discovery of the terminal is reduced. In addition, when the discovery signal transmission interval is increased, the discovery signal reception performance of the terminal is improved, but the base station energy efficiency decreases and neighbor cell interference due to the discovery signal is increased.
  • a discovery signal should be defined so as to reduce unnecessary discovery signal transmission of the base station, improve discovery signal reception performance of the terminal, and minimize time required for cell discovery and time / frequency synchronization of the terminal.
  • the terminal should be able to perform a search for as many cells as possible through the discovery signal.
  • the number of small base stations existing in the macro base station area is increasing. Therefore, as the number of small base stations increases, the number of idle base stations is also expected to increase. Therefore, the UE should maximize system performance by searching for as many cells as possible during the period of receiving the discovery signal.
  • the present invention defines several types of discovery signals.
  • the discovery signal according to the present invention will be described in more detail.
  • FIG. 8 is a diagram illustrating a multiplexed discovery signal on a time axis.
  • a plurality of base stations may transmit a discovery signal using different times within the same discovery signal transmission interval 802.
  • the discovery signal transmission time of the base station A, the base stations B, and the C in one discovery transmission period 802 is divided by a time axis by a predetermined offset 804, and the base station A, the base stations B, and C Can transmit the discovery signal without mutual interference.
  • the plurality of base stations may transmit the discovery signal without mutual interference using the offset 803 in the same discovery signal transmission interval 802 as the base stations B and C (807 and 808).
  • the base station may transmit different discovery signals 805 and 806 in the same discovery signal transmission interval to improve the discovery signal reception performance of the terminal, such as the base station A.
  • the first embodiment is a method in which a UE defines a CSI-RS signal used for measuring channel quality from a base station as a discovery signal in an LTE / LTE-A system.
  • the CSI-RS-based discovery signal is expressed as a D-CSI-RS in order to distinguish the previously used CSI-RS signal and the CSI-RS signal-based discovery signal.
  • the discovery signal means a CSI-RS based discovery signal (D-CSI-RS).
  • the CSI-RS is transmitted through at least one resource among the predefined CSI-RS resource regions 908 as shown in FIG. 9, and different periods and resources may be configured for each base station.
  • FIG. 9 illustrates CSI-RS resource mapping corresponding to CSI-RS configuration 0 909 when a predetermined base station uses four CSI-RSs in a 1RB pair.
  • 9 and 10 illustrate an example in which four CSI-RS signals are used, but other numbers of CSI-RS signals including 1,2 or 8 may be used in addition to the four CSI-RSs. .
  • the CSI-RS signal is used as a discovery signal (D-CSI-RS)
  • D-CSI-RS discovery signal
  • ZP-CSI-RS zero power CSI-RS
  • the CSI-RS can be transmitted in the entire frequency band, it is possible to obtain a base station discovery performance higher than the PSS / SSS signal based discovery signal reception performance based on the same time. Therefore, when the base station transmits the D-CSI-RS signal, the terminal can be detected more accurately when using the discovery signal based on the PSS / SSS signal during the same discovery time, so that a relatively idle base station can be detected more quickly. can do. In other words, when the D-CSI-RS signal is defined as described above, the idle base station may be quickly switched to the active state than the PSS / SSS-based discovery signal.
  • the terminal should receive information related to the CSI-RS of the base station from the base station.
  • the base station is information related to the CSI-RS, CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration, CSI-RS subframe configuration, transmission power relationship between PDSCH and CSI-RS, variables for random signal generation and quasi-co-location-related variables may be transmitted to the terminal.
  • the D-CSI-RS signal related information may be set by reusing the same value as the CSI-RS related information or defining additional variables without defining additional information variables according to the characteristics of the information.
  • the transmission period of the D-CSI-RS signal may be generally set longer than the conventional CSI-RS transmission period. Therefore, a variable such as a D-CSI-RS subframe configuration may be additionally defined to transmit separate D-CSI-RS signal transmission period information.
  • the integer multiple (i) as described above may be defined in advance or included in the D-CSI-RS-related information and transmitted to the terminal.
  • the D-CSI-RS signal transmission resource region can be used in the same manner as the CSI-RS signal transmission resource region. Accordingly, the base station may additionally define a D-CSI-RS configuration variable and set the same as a CSI-RS configuration in use or set a separate value. Or, the base station may be to reuse the existing CSI-RS configuration without additional variable definition.
  • the information related to the D-CSI-RS may further include information about a frequency band (RB index) through which the D-CSI-RS discovery signal is transmitted.
  • the information related to the D-CSI-RS may include newly defined D-CSI-RS configuration information.
  • the discovery signal related information may be delivered to the terminal through higher-layer signaling or L1 signaling such as RRC signaling, or may be delivered to the terminal through SIB.
  • the discovery signal related information may be previously defined between at least one of information such as a base station identifier (cell ID), an SFN, a base station state, and an available frequency resource region (number of RBs) between the terminal and the base station. Can be.
  • CSI-RS signals are transmitted in all frequency bands. Accordingly, the D-CSI-RS discovery signal may also be transmitted in all frequency bands.
  • the Rel-8 and Rel-9 UEs do not know the information about the D-CSI-RS discovery signal transmitted periodically, interference from the discovery signal cannot be avoided using ZP-CSI-RS. . Therefore, if the discovery signal is periodically transmitted through all frequency bands, the Rel-8 and Rel-9 terminals receive interference by the discovery signal in all frequency bands. If the base station serving the Rel-8 and Rel-9 terminals is aware of the discovery signal related information about the neighbor base stations, the interference can be avoided by not scheduling the terminal in the region where the discovery signal is transmitted. However, there is a limit in base station operation and resource utilization. Therefore, it is desirable to minimize the impact on existing terminals by transmitting a discovery signal in a minimum time / frequency resource region.
  • the D-CSI-RS discovery signal is defined to be transmitted only in some frequency domains.
  • the base station may add and transmit information on a discovery signal allocation resource region (eg, one or more RB indexes) to the terminal in addition to the D-CSI-RS related information mentioned in the first embodiment.
  • a discovery signal allocation resource region eg, one or more RB indexes
  • the base station may set the discovery signal to be transmitted only in some predefined frequency regions without additional information transfer.
  • the base station delivers additional information on the discovery signal allocation resource region to the terminal, not only an additional signaling overhead for transmitting the frequency domain related information is increased, but also the terminal is configured to receive a single discovery signal for various frequency bands. Since the receiving operation must be performed, the complexity of the terminal can be increased. Therefore, it may be efficient to transmit the discovery signal using a predefined band.
  • the LTE / LTE-A system can support various frequency bands from 1.4 MHz to 20 MHz. At this time, in the case of the 1.4MHz frequency band using the smallest frequency band, the base station can use a maximum of 6RB. Since the discovery signal defined as described above should be usable in various system frequency bands, the discovery signal is preferably set in at least 6 RB units to support a variable frequency band.
  • C 11 is a frame structure when a discovery signal is defined in units of C RBs.
  • the discovery signal transmission in a fixed unit is defined as described above, since the UE may perform a reception operation in the defined discovery signal region unit, the complexity of the UE may be reduced.
  • the discovery signal defined as described above may be supported in both LTE / LTE-A system bands of various sizes.
  • the base station since the base station only needs to inform the terminal of a single frequency region (RB index start point or end point) instead of a plurality of frequency regions, the signaling overhead can be reduced.
  • Frequency resource related information used by the discovery signal may be delivered to the terminal through higher-layer signaling such as RRC signaling or L1 signaling, or may be delivered to the terminal through SIB.
  • the information may be previously defined using at least one of information such as a base station identifier (cell ID), an SFN, a slot, a base station state, and an available frequency resource region (number of RBs) between the terminal and the base station. .
  • a plurality of base stations may transmit a discovery signal without interference by multiplexing radio resources on a frequency axis. For example, when base stations using 50 RBs transmit discovery signals in units of 6 RBs, up to 8 base stations may transmit discovery signals without mutual interference in different resource regions.
  • a larger number of base stations may simultaneously transmit a discovery signal without mutual interference according to the CSI-RS configuration.
  • more base stations can be multiplexed.
  • the third embodiment is a power control method for improving the discovery signal reception performance of a terminal when using the frequency-multiplexed D-CSI-RS discovery signal as in the first and second embodiments.
  • a discovery signal for allowing a terminal to quickly discover the base stations should be defined. That is, the discovery signal should be defined so that the UE can discover as many base stations as possible for a short time. To this end, the discovery signal may be allocated to use more resources on the time axis and the frequency axis.
  • the discovery signal uses minimum time and frequency resources. desirable.
  • a third embodiment provides a power control method of a discovery signal for improving the discovery signal reception performance of a terminal.
  • the base station When an idle base station transmits a discovery signal, the base station is free to use radio resources such as time, frequency, and power since there is no terminal for providing a data service.
  • the base station when transmitting a discovery signal in units of 6RB as in the second embodiment, signal transmission is not required outside the corresponding discovery signal transmission frequency domain. Accordingly, the base station may allocate higher transmission power to frequency resources allocated for discovery signal transmission.
  • FIG. 12 is a diagram illustrating power control on a discovery signal. In FIG. 12, it is assumed that a predetermined base station operates as an idle base station without a terminal transmitting and receiving data services.
  • the idle base station may not transmit data channels, control channels, and RS signals other than the discovery signal. Accordingly, the idle base station may allocate additional power to the discovery signal 1201.
  • the x-axis represents a frequency resource (RB index) 1203 and the y-axis represents a magnitude 1202 of transmission power for each frequency resource.
  • the base station may allocate power 1204 higher than the transmit power 1205 used for data channel transmission or CSI-RS transmission to the discovery signal.
  • the terminal can reduce the base station search time than when the base station does not perform the power control.
  • FIG. 13 is a diagram illustrating a reception power of a terminal for multiplexed discovery signals.
  • FIG. 13 shows a reception power of a terminal for discovery signals of idle base stations multiplexed on a frequency as in the second embodiment.
  • the UE A discovery signal in A and Cell B can be received without interference.
  • the UE may receive the discovery signals with different received powers as shown in 1305 and 1306. In FIG. 13, it is assumed that the channel sizes between the terminal, the base station A, and the base station B are all 1.
  • Discovery signal transmission power (P d) to be used for each base station may be set to the same value as P c (ratio of PDSCH EPRE to CSI-RS EPRE) is used to notify the CSI-RS transmission power.
  • discovery signal transmission power used by each base station may be defined as a new D-CSI-RS transmission power value, such as P d (ratio of PDSCH EPRE to D-CSI-RS EPRE).
  • the discovery signal transmission power used for each base station is P d (ratio of CSI-RS EPRE to D-CSI-RS EPRE) or P d (ratio of D-CSI-RS EPRE to CSI-RS EPRE). It can be defined as an additional offset value for the predefined P c .
  • Power-related information (eg, P d ) used by the discovery signal may be delivered to the terminal through higher-layer signaling such as RRC signaling or L1 signaling, or may be delivered to the terminal through SIB.
  • the information may be previously defined using at least one of information such as a base station identifier (cell ID), an SFN, a slot, a base station state, and an available frequency resource region (number of RBs) between the terminal and the base station. .
  • the transmission power setting as described above may be applied differently according to the discovery signal configuration. For example, when a predetermined base station transmits a discovery signal such as D-CSI-RS discovery signal type 1 1409 as shown in FIG. 14, since only two REs are used in one OFDM symbol 1401, the RE is used. Up to about six times the average power per unit can be allocated to the D-CSI-RS signal. If the base station transmits a discovery signal such as the D-CSI-RS discovery signal type 2 1410, since only one RE is used in one OFDM symbol 1401, the power is approximately 10 times higher than the average power per RE. May be allocated to the D-CSI-RS signal.
  • the above scheme includes discovery signal type3 1411 and type4 1412 to perform discovery signal transmission resource mapping and power allocation operations in various types of configurations.
  • the fourth embodiment relates to an operation in which the UE recognizes a state transition of the base station when the base station uses the D-CSI-RS discovery signal.
  • the terminal may acquire synchronization using the received discovery signal, measure channel quality of the corresponding base station, and report measurement information to the base station connected to the terminal.
  • the base station receiving the measurement information may switch the idle base station to the active state by using the reported information.
  • the base station switched to the active state may stop the discovery signal transmission or maintain the discovery signal transmission.
  • the discovery signal transmitted by the active base station as described above may be a predefined PSS / SSS signal or may be a D-CSI-RS discovery signal defined in the present invention.
  • the terminal may not recognize whether the base station is switched state.
  • the base station no longer transmits a discovery signal, and thus the terminal cannot receive the discovery signal.
  • the terminal does not know whether the base station is switched to the active state and did not receive the discovery signal, or whether the base station transmits the discovery signal but the terminal itself did not receive correctly. Therefore, there is a need for a method for the terminal to be aware of the base station state transition as described above.
  • the terminal may determine whether to switch the state of the idle base station using the PSS / SSS signal transmitted from the active base station.
  • the base station transmitting the D-CSI-RS discovery signal in the idle state is switched to the active state, the base station may stop the transmission of the D-CSI-RS discovery signal, but the PSS / SSS transmission operation must be performed. Accordingly, when the terminal receiving the D-CSI-RS discovery signal receives the PSS / SSS signal of the base station, the terminal may determine that the base station is active. If the D-CSI-RS discovery signal can be transmitted from the active base station, when the terminal simultaneously receives the D-CSI-RS and the PSS / SSS signal or receives only the PSS / SSS signal, the base station is activated. You can judge.
  • a divided CSI-RS or D-CSI-RS configuration may be defined according to the base station state. For example, as shown in FIG. 15, when a discovery signal is transmitted according to a specific D-CSI-RS configuration 1509 or in a specific time / frequency region 1510 or 1511, the UE is configured for the configuration and time / frequency region. The combination may determine the state of the base station as an active state. For example, when a discovery signal is transmitted in a specific time / frequency region 1512 in FIG. 15, the terminal may determine a state of a corresponding base station as an idle state.
  • the D-CSI-RS configuration and time / frequency domain division as shown in FIG. 15 are just examples and may be configured in various types of combinations. For example, when the discovery signal is transmitted in the 1512 region, the terminal may be configured to determine the state of the base station as an active state.
  • the base station connected to the terminal may directly inform the terminal whether to switch the state of the idle base station. For example, as shown in step 504 of FIG. 5, the terminal that receives the handover command from the base station may recognize that the base station is switched to an active state. Alternatively, the base station notifies the handover command of when the target base station (idle base station) is switched to the active state so that the terminal can know the time of switching the active phase of the base station. Alternatively, the base station may inform the terminal of the idle state base station through higher-layer signaling or L1 signaling such as RRC signaling, or inform the terminal of the base station state information through the SIB.
  • L1 signaling such as RRC signaling
  • the plurality of base stations may transmit the discovery signal without interference.
  • the discovery signal when base stations using 50 RBs transmit discovery signals in units of 6 RBs, up to eight base stations may transmit discovery signals without mutual interference using different resource regions.
  • different base stations use different CSI-RS configurations in the same 6RB, a larger number of base stations may simultaneously transmit a discovery signal according to the CSI-RS configuration.
  • more base stations when different base stations transmit discovery signals using subframe offsets in the discovery signal transmission interval, more base stations may be multiplexed.
  • the active base station transmits the same.
  • the discovery signal may be transmitted at the same location as the PSS / SSS signal.
  • the PSS / SSS of the active base station may be affected by interference from the discovery signal.
  • the influence of interference on the PSS / SSS signal may increase.
  • the base station when transmitting a discovery signal according to a predetermined frequency region as described above, the base station is set not to transmit the discovery signal in the frequency region in which the PSS / SSS signal is transmitted, that is, the 6RB region of the center band of the frequency band Can be. That is, the time / frequency band through which the discovery signal can be transmitted may be set to be different from the time / frequency band through which the PSS / SSS signal is transmitted. Accordingly, the discovery signal transmission may be restricted at the time point at which the PSS / SSS signal is transmitted, or the discovery signal may be transmitted only in a region other than the frequency region in which the PSS / SSS signal is transmitted. In addition, as illustrated in FIG. 16, the discovery signal may be set to be transmitted only in the region 1610 except for the region 1611 in which the PSS / SSS may be transmitted.
  • the terminal since the PSS / SSS signal transmission region and the discovery signal transmission region are divided, the terminal performs the reception operation on the PSS / SSS signal region and the reception operation on the discovery signal region separately, thereby providing the fourth embodiment.
  • whether the state changes for a specific base station can be recognized.
  • the terminal receiving the PSS / SSS signal in the 1611 region may recognize that the corresponding base station is active.
  • the terminal that simultaneously receives the PSS / SSS signal in the region 1611 and simultaneously receives the discovery signal in the region 1610 may recognize that the corresponding base station is active.
  • the UE when a UE that does not receive a PSS / SSS signal in an area 1611 receives a discovery signal in an area 1610, the UE may recognize that the corresponding base station is in an idle state.
  • FIG. 17 is a diagram illustrating a base station apparatus according to an embodiment of the present invention. Devices not directly related to the present invention are omitted for convenience of description.
  • the base station apparatus 1700 includes a transmitter 1701 including a discovery signal block, a PSS / SSS block, a PDCCH block, a PDSCH block, a multiplexer, and a transmit RF block, a PUCCH block, a PUSCH block, a demultiplexer,
  • the receiver 1703 and the controller 1705 are configured as receiving RF blocks.
  • the transmitter 1701 and the receiver 1703 may be collectively referred to as a communication unit, a transceiver, an RF unit, or the like.
  • the controller 1705 controls the respective building blocks of the transmitter 1701 and the receiver 1703 to generate and acquire a promised signal, and determines whether to operate the base station 1700 in an idle state or an active state. Play a role.
  • the discovery signal block generates a discovery signal to be mapped to a predetermined time-frequency domain under the control of the controller 1705.
  • the PSS / SSS block generates the PSS / SSS under the control of the controller 1705.
  • the PDCCH block generates a physical downlink control channel (PDCCH) by performing channel coding and modulation on downlink control information including scheduling information and the like under the control of the controller 1705.
  • the PDSCH block generates a physical downlink shared channel (PDSCH) by performing channel coding, modulation, and the like on the downlink data under the control of the controller 1705.
  • Discover signals, PSS / SSS, PDCCH, and PDSCH generated in each Discovery signal block, PSS / SSS block, PDCCH block, and PDSCH block are multiplexed by a multiplexer, mapped in the time-frequency domain, and then processed in a transmit RF block. After that, it is transmitted to the terminal.
  • the receiving unit 1703 of the base station 1700 demultiplexes the signal received from the terminal and distributes the signal to the PUCCH block and the PUSCH block, respectively.
  • the PUCCH block performs processes such as demodulation and channel decoding on a PUCCH including a UCI to obtain information such as HARQ-ACK / NACK and CSI.
  • the PUSCH block performs processes such as demodulation and channel decoding on a PUSCH (Physical Uplink Shared Channel) including uplink data of the terminal to obtain uplink data transmitted by the terminal.
  • the receiving unit 1703 of the base station 1700 applies the output results of the PUCCH block and the PUSCH block to the control unit 1705 to utilize the data transmission process.
  • FIG. 18 illustrates a terminal device according to an embodiment of the present invention. Devices not directly related to the present invention are omitted for convenience of description.
  • the terminal 1800 includes a transmitter 1801 including a PUCCH block, a PUSCH block, a multiplexer, and a transmit RF block, a discovery signal block, a PSS / SSS block, a PDCCH block, a PDSCH block, a demultiplexer, and a reception unit.
  • a receiver 1803 and a controller 1805 are configured as RF blocks.
  • the transmitter 1801 and the receiver 1803 may be collectively referred to as a communication unit, a transceiver, an RF unit, or the like.
  • the controller 1805 controls the discovery signal receiving operation of the terminal 1800 from the control information received from the base station, and controls the respective building blocks of the receiver 1803 and the transmitter 1801.
  • the discovery signal block in the receiver 1803 performs a process of the terminal 1800 obtaining a discovery signal in a time-frequency domain previously promised.
  • the PSS / SSS block performs a process of acquiring the PSS / SSS by the terminal 1800 in the time-frequency domain previously promised.
  • the PDCCH block performs downlink demodulation, channel decoding, and the like on the PDCCH received by the UE 1800 to obtain downlink control information.
  • the PDSCH block performs downlink demodulation, channel decoding, and the like on the PDSCH received by the UE 1800 to obtain downlink data.
  • the PUCCH block in the transmitter 1801 generates a PUCCH by performing a process such as channel coding and modulation on a UCI including HARQ-ACK / NACK, CSI, and the like.
  • the PUSCH block performs a process such as channel coding or modulation on uplink data to generate a PUSCH.
  • Each PUCCH block, a PUCCH generated in the PUSCH block, and a PUSCH are multiplexed by a multiplexer, signal-processed in a transmission RF block, and then transmitted to a base station.

Landscapes

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

Abstract

La présente invention concerne un système de communication sans fil cellulaire, et, plus particulièrement, un procédé pour rechercher une station de base prédéterminée par un terminal par définition d'un signal de découverte, reconnaissance d'un état de la station de base, acquisition d'une synchronisation de temps/fréquence de la station de base, et mesure d'une intensité d'un signal provenant de la station de base, de façon à permettre à la station de base de fonctionner dans une pluralité d'états, tels qu'un état actif et un état de veille.
PCT/KR2014/012921 2013-12-26 2014-12-26 Procédé et appareil pour émettre/recevoir un signal de découverte dans un système de communication sans fil WO2015099499A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020130163748A KR102225990B1 (ko) 2013-12-26 2013-12-26 무선 통신 시스템에서 디스커버리 신호를 송/수신하는 방법 및 장치
KR10-2013-0163748 2013-12-26

Publications (1)

Publication Number Publication Date
WO2015099499A1 true WO2015099499A1 (fr) 2015-07-02

Family

ID=53479258

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2014/012921 WO2015099499A1 (fr) 2013-12-26 2014-12-26 Procédé et appareil pour émettre/recevoir un signal de découverte dans un système de communication sans fil

Country Status (2)

Country Link
KR (1) KR102225990B1 (fr)
WO (1) WO2015099499A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102358569B1 (ko) 2017-09-15 2022-02-04 삼성전자 주식회사 광대역 시스템을 위한 이동 통신 방법 및 장치

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080188215A1 (en) * 2006-11-17 2008-08-07 Telefonaktiebolaget Lm Ericsson (Publ) Transmission of special neighbor cell lists
US20120163305A1 (en) * 2010-12-28 2012-06-28 Motorola Mobility, Inc. Energy-saving base station and method
KR20120085904A (ko) * 2006-06-20 2012-08-01 인터디지탈 테크날러지 코포레이션 무선 통신 시스템에서의 핸드오버를 수행하기 위한 방법 및 시스템

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20100088855A (ko) * 2009-02-02 2010-08-11 삼성전자주식회사 매크로 및 펨토 셀들을 가지는 무선 통신 네트워크의 측정 보고 방법 및 이를 위한 시스템
KR101637587B1 (ko) * 2010-04-07 2016-07-07 엘지전자 주식회사 펨토 기지국에서 연결 설정을 제어하는 방법 및 단말에서 연결을 설정하는 방법

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120085904A (ko) * 2006-06-20 2012-08-01 인터디지탈 테크날러지 코포레이션 무선 통신 시스템에서의 핸드오버를 수행하기 위한 방법 및 시스템
US20080188215A1 (en) * 2006-11-17 2008-08-07 Telefonaktiebolaget Lm Ericsson (Publ) Transmission of special neighbor cell lists
US20120163305A1 (en) * 2010-12-28 2012-06-28 Motorola Mobility, Inc. Energy-saving base station and method

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CMCC: "Procedures for efficient discovery of small cells", R1-132547, 3GPP TSG-RAN WG1 #73, 20 May 2013 (2013-05-20) - 24 May 2013 (2013-05-24), FUKUOKA, JAPAN, pages 1 - 5, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/wg1_rl1/TSGR1_73/Docs/R1-132547.zip> *
HUAWEI ET AL.: "Efficient discovery of small cells and the configurations", R1-130895, 3GPP TSG RAN WG1 MEETING #72BIS, 15 April 2013 (2013-04-15) - 19 April 2013 (2013-04-19), CHICAGO, USA, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/wg1_rl1/TSGR1_72b/Docs/R1-130895.zip> *

Also Published As

Publication number Publication date
KR20150076319A (ko) 2015-07-07
KR102225990B1 (ko) 2021-03-11

Similar Documents

Publication Publication Date Title
WO2018062898A1 (fr) Procédé et appareil de sélection de ressource et de transmission de pssch dans un système de communication sans fil
WO2014092475A1 (fr) Procédé et appareil d&#39;émission/réception de signal de découverte pour une utilisation dans un système de communication mobile
WO2014168412A1 (fr) Procédé et appareil de communication de dispositif à dispositif destinés à être utilisés dans un système de communication sans fil
WO2012153995A2 (fr) Procédé et appareil de sélection de cellule dans un système de communication sans fil
WO2014104627A1 (fr) Appareil et procédé de réalisation d&#39;une communication de dispositif à dispositif dans un système de communications sans fil
WO2011139063A2 (fr) Procédé et appareil de reconfiguration de canal de commande dans un système de communication sans fil
WO2014137170A1 (fr) Procédé et appareil pour émettre/recevoir un signal associé à une communication de dispositif à dispositif dans un système de communication sans fil
WO2014051333A1 (fr) Procédé et appareil pour prendre en charge un plan de commande et un plan d&#39;utilisateur dans un système de communication sans fil
WO2013066126A1 (fr) Procédé pour transmettre et recevoir un signal de référence dans un système d&#39;accès sans fil, et appareil pour la mise en œuvre de ce procédé
WO2014051334A1 (fr) Procédé et appareil pour utiliser une pluralité de cellules dans un système de communication
WO2014088295A1 (fr) Procédé et appareil de prise en charge de plan de commande et de plan utilisateur dans un système de communication sans fil
WO2013032251A2 (fr) Procédé de prise en charge d&#39;une communication dispositif à dispositif dans un réseau cellulaire, et appareil pour celui-ci
WO2010143911A2 (fr) Dispositif et procédé de rapport de mesures et dispositif dans un système de communication sans fil
WO2014109561A1 (fr) Procédé et appareil pour réaliser une mesure dans un système de communication sans fil
WO2013028044A2 (fr) Procédé d&#39;exécution d&#39;une communication directe entre des terminaux, procédé de prise en charge de cette communication, et appareil pour cette communication
WO2012150822A2 (fr) Procédé de réception d&#39;un signal de liaison descendante, dispositif utilisateur, procédé d&#39;émission d&#39;un signal de liaison descendante, et station de base associée
WO2010104335A2 (fr) Procédé et appareil de transfert dans un système à multiples porteuses
WO2013051858A2 (fr) Procédé et appareil pour resélectionner une cellule dans des réseaux hétérogènes dans un système de communication sans fil
WO2016208953A1 (fr) Procédé et appareil de mise en œuvre de communication dans un système de communication sans fil
WO2020185002A1 (fr) Procédé et appareil permettant de réaliser une communication dans un système de communication sans fil
WO2019107969A1 (fr) Procédé et appareil pour mesurer une qualité de signal dans un système de communication sans fil
WO2016021945A1 (fr) Procédé et dispositif pour communiquer dans une bande non autorisée
WO2015020501A1 (fr) Procédé et appareil de demande de programmation dans un système de communication mobile cellulaire
WO2015194857A1 (fr) Procédé et appareil permettant de réaliser une opération d2d dans une porteuse non activée dans un système de communication sans fil
WO2015174805A1 (fr) Procédé et appareil d&#39;émission et de réception de signaux par un terminal, selon le mode dispositif à dispositif, dans un système de communication sans fil

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: 14874413

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14874413

Country of ref document: EP

Kind code of ref document: A1