KR20130017936A

KR20130017936A - Transmission point, channel status information reference signal signaling method of transmission point, user equipment, and channel status information reporting method of user equipment

Info

Publication number: KR20130017936A
Application number: KR1020110080681A
Authority: KR
Inventors: 윤성준
Original assignee: 주식회사 팬택
Priority date: 2011-08-12
Filing date: 2011-08-12
Publication date: 2013-02-20
Also published as: WO2013024991A3; WO2013024991A2

Abstract

PURPOSE: A transmission terminal, a channel status information reference signal configuration signaling method of the transmission terminal, a terminal, and a channel status information reporting method of the terminal reports channel status information using a CSI-RS pattern. CONSTITUTION: A broad area transmission terminal sets a CSI-RS configuration information which includes an information about CSI-RS transmission frequency and offset, an information about the number of antenna ports, and an information about a CSI-RS pattern(S910). The broad area transmission terminal transmits the configuration information of CSI-RS to RRH through an optical fiber(S920). The configuration information of CSI-RS is transmitted to a terminal through an upper layer signaling such as RRC(S930). Each transmission terminal transmits CSI-RS which is specified to terminal(S940). The terminal estimates a channel status information(S950). The terminal transmits the estimated channel status information(S960). [Reference numerals] (510) Terminal; (520) Broad area transmission terminal; (S910) Setting CSI-RS configuration information; (S920) Transmitting the configuration information of CSI-RS transmitted from RRH; (S930) Transmitting the configuration information of CSI-RS; (S940) Transmitting CSI-RS; (S950) Estimating channel status information; (S960) Transmitting the channel status information

Description

Signaling method of the transmitter, the channel status information reference signal configuration of the transmitter, the terminal, and the channel status information reporting method of the terminal {Transmission Point, Channel Status Information Reference Signal Signaling Method of Transmission Point, User Equipment, and Channel Status Information Reporting Method of User Equipment}

The present invention relates to a system in which a terminal communicates with a plurality of transmission terminals having the same cell ID.

As communication systems evolve, consumers, such as businesses and individuals, have used a wide variety of wireless terminals. Current 3GPP in (3 ^rd Generation Partnership Project) series of the LTE (Long Term Evolution), LTE-A mobile communications system such as (LTE Advanced) out of a service-oriented voice that can transmit and receive various data such as video, wireless data As a high-speed large-capacity communication system, the development of a technology capable of transmitting large-capacity data corresponding to a wired communication network is in progress.

Such a mobile communication system is connected to a plurality of transmission terminals, for example, a wide area transmission terminal having a wide coverage, such as a base station, and a wide area transmission terminal and an optical fiber in order to transmit a large amount of high-speed data, and has the same cell ID as the wide area transmission terminal. And a system having a narrow coverage and RRH (Remote Radio Head) to cooperate to perform communication.

When the terminal communicates with the plurality of transmitters, the channel state should be estimated between the transmitters in order to communicate with each transmitter. In order to estimate a channel state in downlink, a reference signal transmitted by each transmitter may be used.

The present invention relates to a wireless communication system and, when a plurality of transmitting terminals having the same cell ID transmit a reference signal, an apparatus and method for constructing and signaling a pattern not indicated by the current reference signal configuration method, and such a pattern An object of the present invention is to provide an apparatus and a method for receiving a reference signal and reporting a channel state by using the.

In order to achieve the above object, an embodiment of the present invention provides a channel status information reference signal (CSI-RS) which transmits a downlink signal to a terminal and is transmitted by a plurality of transmitting terminals having the same cell ID. CSI-RS setting unit for setting the configuration information of; An interface for transmitting CSI-RS configuration information transmitted from another transmitting end among the CSI-RS configuration information set by the CSI-RS setting unit to the other transmitting end; And a transmitting unit transmitting the CSI-RS configuration information set by the CSI-RS setting unit to the terminal, wherein the CSI-RS configuration information is transmitted by the CSI-RS when the number of CSI-RS antenna ports is 5 or 6 It provides a transmitting end, characterized in that it comprises information on the resource element.

According to another embodiment of the present invention, configuration information of a channel status information reference signal (CSI-RS) transmitted from a plurality of transmission terminals having a same cell ID and a downlink signal is transmitted to a terminal. step; Transmitting configuration information of the CSI-RS transmitted from another transmitting end of the CSI-RS configuration information to the other transmitting end; And transmitting CSI-RS configuration information to the terminal, wherein the CSI-RS configuration information includes information on a resource element through which the CSI-RS is transmitted when the number of CSI-RS antenna ports is 5 or 6 It provides a channel state information reference signal configuration signaling method of the transmitting end.

According to another embodiment of the present invention, channel state information reference signal (CSI-RS) configuration information transmitted from a plurality of transmission terminals having the same cell ID is received and based on the CSI-RS configuration information. A transmission / reception unit configured to receive CSI-RSs transmitted from the plurality of transmitters and to transmit estimated channel state information based on the received CSI-RSs; And a feedback unit for inferring the channel state information based on the CSI-RS, wherein the CSI-RS configuration information includes a resource element for transmitting CSI-RS when the number of CSI-RS antenna ports is 5 or 6; Provided is a terminal comprising information.

Another embodiment of the present invention, receiving the channel status information reference signal (CSI-RS) configuration information transmitted from a plurality of transmitters having the same cell ID; Receiving CSI-RSs transmitted from the plurality of transmitters based on the CSI-RS configuration information; Inferring channel state information based on the CSI-RS; And transmitting the channel state information, wherein the CSI-RS configuration information includes information on a resource element through which the CSI-RS is transmitted when the number of CSI-RS antenna ports is 5 or 6 A channel state information reporting method of a terminal is provided.

According to the embodiments of the present invention described above, a CSI-RS pattern is configured, signaled, and used for a case in which the number of CSI-RS antenna ports is 5 or 6, which is not indicated by the current reference signal configuration method. Channel status information can be reported.

1 illustrates an example of a communication system.
FIG. 2 illustrates an example of downlink resources through which CSI-RSs are transmitted when the number of antenna ports is 1 or 2 in a normal CP.
3 shows an example of a downlink resource in which a CSI-RS is transmitted when the number of antenna ports is 4 in a normal CP.
4 illustrates an example of downlink resources through which CSI-RSs are transmitted when the number of antenna ports is 8 in a normal CP.
5 illustrates an example of a system in which a terminal communicates with a plurality of transmission terminals having the same cell ID.
6 illustrates an example of a configuration of a wide area transmission stage in the system of FIG. 5.
FIG. 7 shows an example of configuration of an RRH in the system of FIG. 5.
8 illustrates an example of a configuration of a terminal in the system of FIG. 5.
9 illustrates an example of a method executed in the system of FIG.
10A through 10D illustrate examples of downlink resources through which CSI-RSs are transmitted when the number of antenna ports is 5 or 6 in a normal CP.
11A to 11D illustrate examples of downlink resources through which CSI-RSs are transmitted when the number of antenna ports is 5 or 6 in the extended CP.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 illustrates an example of a communication system.

Communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, a communication system includes a user equipment (UE) 110 and a transmission point 120 that performs uplink and downlink communication with the terminal 10.

In the present specification, a terminal 110 or a user equipment (UE) is a comprehensive concept that means a user terminal in wireless communication. In addition to the UE in WCDMA, LTE, and HSPA, as well as a mobile station (MS) and a UT (GSM) in GSM, It should be interpreted as a concept that includes a user terminal, a subscriber station (SS), and a wireless device.

The transmitting terminal 120 or the cell generally refers to a station communicating with the terminal 110, and includes a base station, a Node-B, an evolved Node-B, and a base transceiver. It may be called other terms such as a System, an Access Point, a Relay Node, and the like.

In the present specification, a transmission terminal 120 or a cell should be interpreted in a comprehensive sense of a part of a region covered by a base station controller (BSC) in a CDMA, a NodeB of a WCDMA, etc., and a radio remote connected to a base station. Comprehensive means any type of device that can communicate with one or more terminals, such as heads, relay nodes, macrocell sectors, sites, and other microcells such as femtocells and picocells. Used as a concept.

In the present specification, the terminal 110 and the transmitter 120 are used as a transmitting and receiving entity used in implementing the technology or the technical idea described in this specification in a comprehensive sense and are not limited to the terms or words specifically referred to.

Although one terminal 110 and one transmission terminal 120 are shown in FIG. 1, the present invention is not limited thereto. One transmission terminal 120 may communicate with the plurality of terminals 110, and one terminal 110 may communicate with the plurality of transmission terminals 120.

There are no limitations to the multiple access scheme applied to a communication system, and the present invention provides the code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), and OFDM. Applicable to various multiple access schemes such as FDMA, OFDM-TDMA, and OFDM-CDMA.

In addition, the present invention is a combination of the TDD (Time Division Duplex) method is transmitted using a different time, uplink transmission and downlink transmission, FDD (Frequency Division Duplex) method is transmitted using a different frequency, combining the TDD and FDD Applicable to hybrid duplexing method.

Specifically, embodiments of the present invention are applicable to asynchronous wireless communication that evolves into Long Term Evolution (LTE) and LTE-advanced through GSM, WCDMA, HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. Can be. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be interpreted as including all technical fields to which the spirit of the present invention can be applied.

Referring to FIG. 1, the terminal 110 and the transmitter 120 may communicate in uplink and downlink.

The transmitting terminal 120 may perform downlink transmission to the terminal 110. The transmitter 120 may transmit a physical downlink shared channel (PDSCH) as a downlink data channel for unicast transmission. In addition, the transmitter 120 may schedule downlink control information such as scheduling required for reception of the PDSCH and transmission for uplink data channel (for example, a physical uplink shared channel (PUSCH)). Physical Downlink Control Channel (PDCCH) as a downlink control channel for transmitting the grant information, Physical Control Format Indicator Channel (Physical Control Format Indicator Channel) for transmitting the indicator for distinguishing the region of PDSCH and PDCCH, PCFICH, a control channel such as a physical HARQ indicator channel (PHICH) for transmitting a hybrid automatic repeat request (HARQ) confirmation for uplink transmission may be transmitted. Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

The terminal 110 may perform uplink transmission to the transmitting terminal 120. The terminal 110 may transmit a PUSCH as a downlink data channel for unicast transmission. In addition, the terminal 110 requests resource allocation when transmitting data through HARQ acknowledgment (NACK) / negative ACK (NACK), channel status report, and uplink indicating whether the downlink transport block has been successfully received. A physical uplink control channel (PUCCH) as an uplink control channel for transmitting uplink control information (UCI) including a scheduling request may be transmitted.

Hereinafter, a situation in which signals are transmitted and received through channels such as PDCCH, PDSCH, PUCCH, and PUSCH will be described as 'sending and receiving PDCCH, PDSCH, PUCCH, and PUSCH'.

The transmitter 120 transmits a Cell-Specific Reference Signal (CRS), an MBSFN Reference Signal (MBSFN-RS), and a UE-Specific Reference Signal (UE) in the downlink. Specific Reference Signal or Demodulation Reference Signal (DM-RS), Positioning Reference Signal (PRS), and CSI Reference Signal (Channel Status Information Reference Signal, CSI-RS) may be transmitted.

The CSI-RS may be used by the terminal 110 to measure channel status information (CSI). The terminal 110 knows the transmission power of the CSI-RS transmitted from the transmission terminal 120 and compares it with the CSI-RS reception power to estimate channel status information (CSI). The estimated channel state information may be transmitted from the terminal 110 to the transmitting terminal 120 through the PUCCH or the PUSCH. The transmitter 120 may perform downlink scheduling based on the received channel state information.

CSI-RS is a specific subframe every certain period on the time axis, and each antenna port for CSI-RS transmission in the region of 12 subcarriers corresponding to one resource block (RB) on the frequency axis. As many as one resource element (RE) is allocated. Next-generation communication technology can support up to eight antennas for downlink, and CSI-RS can also support up to eight within the time-frequency resource region corresponding to one subframe on the time axis and 12 subcarriers on the frequency axis. Is assigned.

In a wireless communication system, the CSI-RS has 1, 2, 4 or 8 antennas using antenna port numbers p = 15, p = 15,16, p = 15-18, p = 15-22, respectively. Sent on the port The transmitter 120 transmits information on the period and offset of CSI-RS transmission subframes and the number of antenna ports for CSI-RS transmission through high layer signaling such as RRC (Radio Resource Control) signaling. Information and information on the CSI-RS pattern can be transmitted. The period of the CSI-RS may be 5, 10, 20, 40 ms, 80 ms, and the information configured to indicate the period and offset of the CSI-RS transmission subframes may be 8 bits. Information on the number of antenna ports for CSI-RS transmission (hereinafter, 'CSI-RS antenna port' and 'antenna port' means antenna ports for CSI-RS transmission unless otherwise noted) is 1 or 2 It may be 2 bits indicating one of 4, 8. The information on the CSI-RS pattern may be 5 bits that designate one in Tables 1 and 2 below. Table 1 below shows a case of normal CP (normal cyclic prefix) and Table 2 shows a case of extended cyclic prefix (CP).

[Table 1]

[Table 2]

In Table 1 and Table 2

Is information about the location of one specific resource element of the CSI-RS pattern.

In a subframe in which the CSI-RS is set to be transmitted, the CSI-RS sequence (

) Is an orthogonal sequence (

And then complex-valued symbols (

).

[Equation 1]

where

In Equation 1

Corresponds to a complex-valued symbol that is mapped to the k th subcarrier and the l th symbol of the p th antenna port, where follows the formula, and the CSI-RS sequence (

) And orthogonal sequences (

) Is multiplied and mapped.

For example, in the normal CP, the number of antenna ports is 1 or 2 (p = 15 or p = 15,16) and the CSI-RS pattern information (CSI-RS configuration (CSI reference signal configuration of Table 1 or Table 2) Number) from 0, from Table 1

Is (9,5), n _s Since mod 2 is 0, we can see that it is located in the first slot. Using Equation 1, it can be seen that the CSI-RS is transmitted in the resource element 210 having ( k , l ) = (9,5), (9,6) in one subframe as shown in FIG. 2. have. In FIG. 2, "220" indicates a control region, "230" indicates a region where the CRS is transmitted, and "240" indicates a region where the DM-RS is transmitted. In FIG. 2, the horizontal axis represents a symbol (time) and the vertical axis represents a subcarrier (frequency). This relationship is the same in FIGS. 3 and 4 below.

If the number of antenna ports in the normal CP is 4 (p = 15, 16, 17, 18) and the CSI-RS pattern information is 0,

Is (9,5) and n _s mod2 is 0, so we can see that it is located in the first slot. Using Equation 1, as in FIG. 3, a resource element having ( k , l ) = (9,5), (9,6), (3,5), (3,6) in one subframe ( In operation 310, the CSI-RS may be transmitted. In FIG. 3, "320" represents a control region, "330" represents a region in which a CRS is transmitted, and "340" represents a region in which a DM-RS is transmitted.

If the number of antenna ports in the normal CP is 8 (p = 15, 16, 17, 18, 19, 20, 21, 22) and the CSI-RS pattern information is 0,

Is (9,5) and n _s mod2 is 0, so we can see that it is located in the first slot. Using Equation 1, ( k , l ) = (9,5), (9,6), (3,5), (3,6), (8, It can be seen that the CSI-RS is transmitted in the resource element 410 which is 5), (8,6), (2,5), and (2,6). In FIG. 4, "420" represents a control region, "430" represents a region in which a CRS is transmitted, and "440" represents a region in which a DM-RS is transmitted.

Meanwhile, in Table 1, when the number of antenna ports is 8 and the CSI-RS pattern information is 0, resource elements mapped for CSI-RS transmission (( k , l ) = (9,5), (9,6) , (3,5), (3,6), (8,5), (8,6), (2,5), (2,6)) (410) has 4 antenna ports and CSI Resource element (( k , l ) = (9,5), (9,6), (3,5), (3,6)) mapped for CSI-RS transmission when -RS pattern information is 0 When (410-1) and the number of antenna ports is 4 and the CSI-RS pattern information is 5, resource elements mapped for CSI-RS transmission (( k , l ) = (8,5), (8,6) ), (2,5), (2,6)) (410-2) is combined. In the same manner, the resource element mapped for CSI-RS transmission when the number of antenna ports is 8 may be represented as the sum of the resource elements mapped for CSI-RS transmission when the number of antenna ports is four.

That is, in Table 1, when the number of antenna ports is 8 and the CSI-RS pattern information is 0 (( k , l ) = (9,5), (9,6), (3,5), (3,6) ), (8,5), (8,6), (2,5), (2,6)) is the number of antenna ports is 4 and the CSI-RS pattern information is 0 (( k , l ) = (9,5), (9,6), (3,5), (3,6)) and when the pattern information is 5 (( k , l ) = (8,5), (8,6), (2,5), (2,6)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 1 (( k , l ) = (11,2), (11,3), (5,2), (5,3), ( 10,2), (10,3), (4,2), (4,3)) is 4 when the number of antenna ports is 4 and the CSI-RS pattern information is 1 (( k , l ) = (11, 2), (11,3), (5,2), (5,3)) and when the pattern information is 6 (( k , l ) = (10,2), (10,3), (4, 2), (4,3)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 2 (( k , l ) = (9,2), (9,3), (3,2), (3,3), ( 8,2), (8,3), (2,2), (2,3)) is 4 when the number of antenna ports and CSI-RS pattern information is 2 (( k , l ) = (9, 2), (9,3), (3,2), (3,3)) and when the pattern information is 7 (( k , l ) = (8,2), (8,3), (2, 2), (2,3)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 3 (( k , l ) = (7,2), (7,3), (1,2), (1,3), ( 6,2), (6,3), (0,2), (0,3)) is 4 when the number of antenna ports is 4 and CSI-RS pattern information is 3 (( k , l ) = (7, 2), (7,3), (1,2), (1,3)) and when the pattern information is 8 (( k , l ) = (6,2), (6,3), (0, 2), (0,3)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 4 (( k , l ) = (9,5), (9,6), (3,5), (3,6), ( 8,5), (8,6), (2,5), (2,6)) is 4 when the number of antenna ports is 4 and the CSI-RS pattern information is 4 (( k , l ) = (9, 5), (9,6), (3,5), (3,6)) and the pattern information is 9 (( k , l ) = (8,5), (8,6), (2, 5), (2,6)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 20 (( k , l ) = (11,1), (11,3), (5,1), (5,3), ( 10,1), (10,3), (4,1), (4,3)) is 4 when the number of antenna ports is 4 and the CSI-RS pattern information is 20 (( k , l ) = (11, 1), (11,3), (5,1), (5,3)) and the pattern information is 23 (( k , l ) = (10,1), (10,3), (4, 1), (4,3)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 21 (( k , l ) = (9,1), (9,3), (3,1), (3,3), ( 8,1), (8,3), (2,1), (2,3)) is 4 when the number of antenna ports is 4 and CSI-RS pattern information is 21 (( k , l ) = (9, 1), (9,3), (3,1), (3,3)) and when the pattern information is 24 (( k , l ) = (8,1), (8,3), (2, 1), (2,3)). If the number of antenna ports is 8 and the CSI-RS pattern information is 22 (( k , l ) = (7,1), (7,3), (1,1), (1,3), (6 , (1), (6,3), (0,1), (0,3)) is the number of antenna ports is 4 and the CSI-RS pattern information is 22 (( k , l ) = (7,1) ), (7,3), (1,1), (1,3)) and the pattern information is 25 (( k , l ) = (6,1), (6,3), (0,1) ), And (0,3)).

Meanwhile, in Table 2, when the number of antenna ports is 8 and the CSI-RS pattern information is 0 (( k , l ) = (11,4), (11,5), (8,4), (8,5) ), (5,4), (5,5), (2,4), (2,5)) is the number of antenna ports is 4 and the CSI-RS pattern information is 0 (( k , l ) = (11,4), (11,5), (8,4), (8,5)) and when the pattern information is 4 (( k , l ) = (5,4), (5,5), (2,4), (2,5)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 1 (( k , l ) = (9,4), (9,5), (6,4), (6,5), ( 3,4), (3,5), (0,4), (0,5)) is 4 when the number of antenna ports and CSI-RS pattern information is 1 (( k , l ) = (9, 4), (9,5), (6,4), (6,5)) and when the pattern information is 5 (( k , l ) = (3,4), (3,5), (0, 4) and (0,5)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 2 (( k , l ) = (10,4), (10,5), (7,4), (7,5), ( 4,4), (4,5), (1,4), (1,5)) is 4 when the number of antenna ports and CSI-RS pattern information is 2 (( k , l ) = (10, 4), (10,5), (7,4), (7,5)) and the pattern information is 6 (( k , l ) = (4,4), (4,5), (1, 4), (1,5)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 3 (( k , l ) = (9,4), (9,5), (6,4), (6,5), ( 3,4), (3,5), (0,4), (0,5)) is 4 when the number of antenna ports and CSI-RS pattern information is 3 (( k , l ) = (9, 4), (9,5), (6,4), (6,5)) and when the pattern information is 7 (( k , l ) = (3,4), (3,5), (0, 4) and (0,5)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 16 (( k , l ) = (11,1), (11,2), (8,1), (8,2), ( 5,1), (5,2), (2,1), and (2,2) are four antenna ports and 16 CSI-RS pattern information (( k , l ) = (11, 1), (11,2), (8,1), (8,2)) and when the pattern information is 19 (( k , l ) = (5,1), (5,2), (2, 1), (2,2)). In addition, when the number of antenna ports is 8 and the CSI-RS pattern information is 17 (( k , l ) = (10,1), (10,2), (7,1), (7,2), ( 4,1), (4,2), (1,1), (1,2)) is 4 when the number of antenna ports is 4 and CSI-RS pattern information is 17 (( k , l ) = (10, 1), (10,2), (7,1), (7,2)) and when the pattern information is 20 (( k , l ) = (4,1), (4,2), (1, 1), (1,2)). If the number of antenna ports is 8 and the CSI-RS pattern information is 18 (( k , l ) = (9,1), (9,2), (6,1), (6,2), (3 , (1), (3,2), (0,1), (0,2)) is the number of antenna ports is 4 and the CSI-RS pattern information is 18 (( k , l ) = (9,1) ), (9,2), (6,1), (6,2)) and pattern information 21 (( k , l ) = (3,1), (3,2), (0,1) ), And (0,2)).

Meanwhile, a communication system in which each transmitting end is independently configured while having the same or similar level of coverage may be called a homogeneous communication network or a homogeneous network, and a heterogeneous network or heterogeneous network ( Heterogeneous Network.

The heterogeneous network may include, for example, a macro transmission point (macro transmission point or macro cell) and a low power remote radio head (RRH). A transmitting end, such as an RRH, may have the same cell ID as a wide area transmitting end, or may operate as an independent cell with a different cell ID.

Typically, a cellular system utilizes radio resources defined in a manner in which multiple cells use the same frequency band or different frequency bands. In a cellular system, a signal transmitted by a transmitter does not propagate more than a predetermined distance, and an area in which a signal propagated by each transmitter may be received is called a cell area or a cell coverage area.

In the cellular system, each cell region is configured independently except for portions overlapping each other. Therefore, even when the same radio resource is used in each cell region, it is possible to perform wireless communication without inter-cell interference.

On the other hand, in the case of a communication network composed of a plurality of cells or transmission terminals in which some or all of the coverage areas overlap, it is possible for each terminal to simultaneously receive or transmit signals and information from the plurality of transmission terminals.

In a modern communication system, a cooperative multi-point wireless communication in which a terminal simultaneously receives information from a plurality of transmission terminals or transmits information to the same terminal through cooperative communication while the plurality of transmission terminals are controlled by the same scheduler. The use of the Coordinated Multi-Point Tx / Rx Communication System (CoMP) is being considered.

CoMP is a CS / CB (Coordinated Scheduling / Coordinated Beamforming) mode in which one transmitting end transmits data and scheduling / beamforming is determined between the transmitting ends, and JP-JT It may be classified into a Joint Processing-Joint Transmission mode, and a JP-DCS (Joint Processing-Dynamic Cell Selection) mode in which a transmission end for transmitting data is dynamically selected.

The CSI-RS may have a plurality of CSI-RS configurations for each cell. The CSI-RS configuration includes a CSI-RS configuration having a non-zero transmission power corresponding to a pattern in which a CSI-RS is transmitted to a UE of each cell (or RRR) and a neighboring cell (or RRR). A CSI-RS configuration having zero transmission power for muting the PDSCH region corresponding to the CSI-RS transmission may be classified.

The CSI-RS configuration having a non-zero transmission power is a configuration for the CSI-RS used by the UE to measure channel state information. At most one configuration may be transmitted to each terminal of the corresponding cell. As described above, the CSI-RS configuration having a transmission power other than zero includes two bits of information on whether the number of CSI-RS antenna ports is 1, 2, 4, and 8, and each CSI-RS antenna as shown in Table 1 or Table 2. 5-bit information on the CSI-RS pattern configurable for each port number may be included.

The CSI-RS configuration having zero transmit power is a configuration for distinguishing muted PDSCH regions. The CSI-RS configuration with zero transmit power is used to indicate the region where PDSCH is not transmitted to avoid interference due to CSI-RS from adjacent cells. The CSI-RS configuration having zero transmit power may be 16-bit bitmap information for each of 16 patterns, which is the maximum number of CSI-RS patterns possible when the number of CSI-RS antenna ports is 4 in Table 1 or Table 2.

Meanwhile, as an example of the CoMP JP / JT mode described above, the UE may perform up-down communication with a plurality of transmission terminals having the same cell ID, for example, a wide area transmission terminal covering a wide area and an RRH covering a narrow area. have. 5 illustrates an example of a system in which a terminal communicates with a plurality of transmission terminals having the same cell ID.

Referring to FIG. 5, the terminal 510 may perform uplink and downlink communication with a wide area transmission terminal 520 covering a wide area and an RRH 530 covering a narrow area. The RRH 530 may communicate with the wide area transmission terminal 520 through an optical fiber and the like and may be controlled by the wide area transmission terminal 520.

Each of the wide area transmitter 520 and the RRH 530 may transmit the same or different downlink data to the terminal 510. At least one of the wide area transmitter 520 and the RRH 530 may transmit a CRS, which is a cell-specific reference signal. Each of the wide area transmitter 520 and the RRH 530 may transmit a DM-RS, which is a reference signal for decoding downlink data to be transmitted, and a CSI-RS, which is a reference signal for estimating a downlink channel state.

Configuration information of the CSI-RS may be transmitted from the wide area transmission terminal 520 or the RRH 530 to the terminal 510 through a high layer signal, for example, RRC. In this case, the configuration information of the CSI-RS transmitted through higher layer signaling such as RRC includes the CSI-RS configuration information transmitted from the RRH 530 as well as the configuration information of the CSI-RS transmitted from the wide area transmission terminal 520. shall. As an example, the configuration information of the CSI-RS transmitted from the wide area transmitter 520 and the configuration information of the CSI-RS transmitted from the RRH 530 may be set in the wide area transmitter 520. The RRH 530 may receive configuration information of the CSI-RS transmitted from the RRH 530 through the optical fiber from the wide area transmitter. The terminal 510 may receive configuration information of the CSI-RS through the RRC transmitted from the wide area transmission terminal 520 and / or the RRH 530.

In FIG. 5, the terminal 510 is described as communicating with one wide transmitter 520 and one RRH 530. However, the present invention is not limited thereto, and the terminal 510 is connected to one wide transmitter 520. And when communicating with the plurality of RRHs 530, the terminal 510 may also be applied when communicating with the plurality of RRHs 530. In addition, although the RRH 530 that communicates with the wide area transmission end 520 through the optical fiber has been described, the communication between the wide area transmission end and the RRH may also communicate in other ways via wired or wireless.

FIG. 6 illustrates an example of a configuration of the wide area transmission stage 520 in the system of FIG. 5. Referring to FIG. 6, the wide area transmitter 520 may communicate with the CSI-RS configuration setting unit 522, the transmitter 524 that performs downlink transmission to the terminal 510, and the RRH 530 through an optical fiber. And a CSI-RS controller 528 for controlling the CSI-RS transmitted from the transmitter 524 according to the CSI-RS configuration information set by the CSI-RS configuration setting unit 522. .

In this embodiment, the CSI-RS configuration setting unit 522 sets both the configuration of the CSI-RS transmitted from the wide area transmission terminal 520 and the configuration of the CSI-RS transmitted from the RRH 530.

For example, when the wide area transmission terminal 520 uses one or two antenna ports and the RRH 530 uses one or two antenna ports, the CSI-RS configuration setting unit 522 may be configured as an antenna port. The number may be selected as 4, and one of antenna patterns for four antenna ports may be selected in Table 1 or Table 2. Two of the four resource elements configured may be used by the wide area transmitter 520 to transmit the CSI-RS, and the other two may be used by the RHR 530 to transmit the CSI-RS.

In another example, when the wide area transmission terminal 520 uses four antenna ports and the RRH 530 uses four antenna ports, the CSI-RS configuration setting unit 522 sets the number of antenna ports to eight. And one of the antenna patterns for the eight antenna ports in Table 1 or Table 2. Four of the configured eight resource elements are used by the wide area transmitter 520 to transmit the CSI-RS, and the other four may be used by the RRH 530 to transmit the CSI-RS.

On the other hand, when the wide area transmitting end 520 uses four antenna ports and the RRH 530 uses one or two antenna ports, the CSI-RS configuration setting unit 522 sets the number of antenna ports to six. And, antenna pattern for 6 antenna ports should be set. However, in the above example, the information about the number of antenna ports does not include information about "6", and Table 1 and Table 2 do not include antenna patterns for six antenna ports. This case will be described later.

In addition, the CSI-RS configuration setting unit 522 may set information (period and offset) for subframes transmitting the CSI-RS. When only one piece of information on a period and offset is set, when the plurality of transmitters 520 and 530 are set to perform downlink transmission, the plurality of transmitters 520 and 530 use CSI-RS with the same period and offset. Will transmit.

The CSI-RS pattern set by the CSI-RS configuration setting unit 522 may be transmitted by the transmitter 524 through higher layer signaling such as RRC. Information on the CSI-RS transmitted from the RRH 530 among the CSI-RS patterns set by the CSI-RS configuration setting unit 522 may be transmitted to the RRH 530 through the optical fiber interface 526. Among the CSI-RS patterns set by the CSI-RS configuration setting unit 522, a pattern for the CSI-RS transmitted by the wide area transmitter 520 may be stored in the CSI-RS controller 528. The CSI-RS controller 528 may control the transmitter 524 to transmit the CSI-RS through the resources set by the CSI-RS configuration setting unit 522.

7 illustrates an example of a configuration of an RRH 530 in the system of FIG. 5. Referring to FIG. 7, the RRH 530 may include an optical fiber interface 532 for communicating with the wide area transmission terminal 520 through an optical fiber, a transmission unit 534 for performing downlink transmission to the terminal 510, and an optical fiber interface ( And a CSI-RS controller 536 that controls the CSI-RS transmitted from the transmitter 534 according to the CSI-RS pattern information received through 532.

The optical fiber interface 532 receives control information from the wide area transmission terminal 520 including pattern information for the CSI-RS transmitted from the RRH 530. The transmitter 534 performs downlink transmission including CSI-RS transmission. The CSI-RS controller 536 is a CSI-RS configuration setting unit 522 of the wide area transmission terminal 520 based on the pattern information for the CSI-RS transmitted from the RRH 530 received through the optical fiber interface 532. The control unit 534 controls the CSI-RS to be transmitted through the resource set in FIG.

8 illustrates an example of a configuration of a terminal 510 in the system of FIG. 5. Referring to FIG. 8, the terminal 510 receives and receives a downlink signal transmitted from the transmitter 520 and 530, and a transceiver 512 and a transceiver for transmitting an uplink signal to the transmitter 520 and 530. The information on the transmission period and offset of the CSI-RS received through 512, the information on the number of antenna ports, and the CSI-RS pattern information are stored and received through the transceiver 512 based on the stored information. The CSI-RS extractor 514 extracts the CSI-RS from the information, and the channel state information is inferred based on the CSI-RS extracted by the CSI-RS extractor 514 and the channel state information is transmitted to the transceiver 512. It includes a feedback unit 516 to deliver.

The transceiver 512 is, for example, 8-bit information on the transmission period and offset of the CSI-RS through RRC, 2-bit information on the number of antenna ports transmitting the CSI-RS, and 5-bit information on the CSI-RS pattern. Information can be received.

The CSI-RS extractor 514 stores information on the transmission period and offset of the CSI-RS, information on the number of antenna ports, and information on the CSI-RS pattern. When the terminal 510 knows that two transmitting terminals 520 and 530 transmit downlink data to the terminal 510 and the number of antenna ports is four, the terminal 510 transmits each transmitting terminal 520, It may be possible to know that 530 transmits the CSI-RS using one or two antenna ports. When the terminal 510 knows that two transmitting terminals 520 and 530 transmit downlink data to the terminal 510 and the number of antenna ports is eight, the terminal 510 transmits each transmitting terminal 520, It may be possible to know that 530 transmits the CSI-RS using four antenna ports. In this example, if only one information about the period and offset is received, the two transmitting end 520, 530 will transmit the CSI-RS in the same period and offset.

After the CSI-RS extractor 514 stores information on the period and offset of the CSI-RS, information on the number of antenna ports, and information on the CSI-RS pattern, the CSI-RS extractor 512 based on the information. The CSI-RS is extracted from the downlink signals received through. The feedback unit 516 estimates channel state information in downlink using the extracted CSI-RS. The channel state information estimated by the feedback unit 516 is transmitted through the transceiver unit 512.

9 illustrates an example of a method executed in the system of FIG.

Referring to FIG. 9, the wide area transmitter 520 may transmit information about the transmission period and offset of the CSI-RS and the antenna port of the plurality of transmitters 520 and 530 that transmit downlink data to the terminal 510. CSI-RS configuration information including information on the number and information on the CSI-RS pattern is set (S910). The information on the number of antenna ports may be the sum of the number of antenna ports in each of the transmitting terminals 520 and 530. The CSI-RS pattern information may be information on a combination of CSI-RS patterns transmitted from each of the transmitting terminals 520 and 530.

For example, when one transmitting terminal 520 transmits the CSI-RS to the pattern information 0 through four antenna ports when the normal CP is a normal CP, the resource element to which the CSI-RS is transmitted from Table 1 and Equation 1 (9,5), (9,6), (3,5), (3,6). When the other transmitting end 530 transmits the CSI-RS with the pattern information 5 through four antenna ports when the normal CP is a normal CP, the resource element to which the CSI-RS is transmitted from Table 1 and Equation 1 is (8,5) , (8,6), (2,5), (2,6). In this case, the resource elements through which the CSI-RSs are transmitted from the plurality of transmission terminals 520 and 530 are (9,5), (9,6), (3,5), (3,6), and (8,5). ), (8,6), (2,5), and (2,6), which is the same as the case of transmitting CSI-RS with pattern information 0 through 8 antenna ports in a normal CP.

The wide area transmitter 520 transmits configuration information of the CSI-RS to be transmitted from the RRH 530, that is, information about a period and offset, the number of antenna ports, and a pattern to the RRH 530 through the optical fiber (S920). .

The wide area transmitter 520 and / or the RRH 530 may configure configuration information of the CSI-RS to be transmitted from the plurality of transmitters 520 and 530 to transmit downlink data to the terminal 510, that is, the period and offset, and the antenna port. Information on the number of patterns and the pattern is transmitted to the terminal 510 through higher layer signaling such as RRC (S930). The number of antenna ports may be the sum of the number of antenna ports in each transmission terminal 520 and 530. The CSI-RS pattern information may be information on a combination of CSI-RS patterns transmitted from each of the transmitting terminals 520 and 530.

Each transmitting terminal 520 and 530 transmits the CSI-RS specific to the terminal 510 (S940). Upon receiving the CSI-RS, the terminal 510 estimates the channel state information using the same (S950). The terminal 510 transmits the estimated channel state information (S960). When downlink scheduling is performed by the wide area transmitter 520, the wide area transmitter 520 receives channel state information transmitted by the terminal 510, or the channel state transmitted by the terminal 510 by the RRH 530. The information may be received and transmitted to the wide area transmitter 520.

Meanwhile, as described above, when the plurality of transmission terminals 520 and 530 all use five or six antenna ports (for example, the wide area transmission terminal 520 uses four antenna ports and the RRH 530 is used). 1 or 2 antenna ports), the information on the antenna pattern for configuring the six resource elements for CSI-RS transmission can not be defined from Table 1 or Table 2 and equation (1).

In one embodiment, a CSI-RS pattern using six antenna ports and having a non-zero transmit power is 2 in 8 resource elements for a CSI-RS pattern using eight antenna ports and having a nonzero transmit power. It can be expressed by removing two resource elements. In the case of removing two resource elements from eight resource elements, all four cases may be possible.

10A to 10D illustrate a case where two resource elements are removed from eight resource elements for eight antenna ports in the case of a normal CP. 10A to 10D, the horizontal axis represents a symbol (time), the vertical axis represents a subcarrier (frequency), "1002" shows a control area, "1004" shows an area where the CRS is transmitted, and "1006". "Shows the area where the DM-RS is transmitted.

As an example, FIGS. 10A to 10D illustrate a case in which eight antenna ports are used in a normal CP, and CSI-RS pattern information in Table 1 is one. If the CSI-RS pattern information is 1,

= (11,2) and n _s mod2 = 1 (second slot), so in the subframe ( k , l ) = (11,9), (11,10), (5,9), (5,10 ), (10,9), (10,10), (4,9), and (4,10) resource elements 1008 are set for CSI-RS for eight antenna ports.

FIG. 10A shows that two resource elements ((4,9) and (4,10) having the lowest k values among the eight resource elements 1008 are omitted so that ( k , l ) = (11,9) in the subframe. In this case, six resource elements 1010a, which are (11, 10), (5, 9), (5, 10), (10, 9), and (10, 10), are used. This is the case when the transmitter having four antenna ports transmits CSI-RS through ( k , l ) = (11,9), (11,10), (5,9), (5,10). In addition, a transmission terminal having one or two antenna ports corresponds to a case of transmitting CSI-RS through ( k , l ) = (10,9) and (10,10). Based on k ´ = 11, k = k ´-0 for p = 15,16, k = k ´-6 for p = 17,18, and k = k ´- for p = 19,20 1, which is the same as Equation 1 described above. This pattern will be referred to as an A pattern.

FIG. 10B shows that two resource elements ((5,9), (5,10)) having the second lowest k value among the eight resource elements 1008 are omitted so that ( k , l ) = (11 in the subframe. This is the case in which six resource elements 1010b are used, which are (9, 9), (11, 10), (10, 9), (10, 10), (4, 9), and (4, 10). This is the case when the transmitting end having four antenna ports transmits CSI-RS through ( k , l ) = (10,9), (10,10), (4,9), (4,10). In addition, a transmission terminal having one or two antenna ports corresponds to a case where CSI-RS is transmitted through ( k , l ) = (11,9) and (11,10). Based on k ´ = 10, k = k ´-0 for p = 15,16, k = k ´-6 for p = 17,18, and k = k ´ + for p = 19,20 It becomes 1 This pattern will be referred to as a B pattern.

10C shows that two resource elements ((10,9) and (10,10)) having the second highest k value among the eight resource elements are omitted so that ( k , l ) = (11,9) in the subframe. In this case, six resource elements 1010c, which are (11, 10), (5, 9), (5, 10), (4, 9), and (4, 10), are used. This is the case when the transmitter having four antenna ports transmits CSI-RS through ( k , l ) = (11,9), (11,10), (5,9), (5,10). In addition, a transmission terminal having one or two antenna ports corresponds to a case of transmitting CSI-RS through ( k , l ) = (4,9) and (4,10). Based on k ´ = 11, if p = 15,16 k = k ´-0, if p = 17,18 k = k ´-6, if p = 19,20 k = k ´ Is -7. This pattern is called a C pattern.

10D shows that two resource elements ((11,9) and (11,10) having the highest k values among the eight resource elements are omitted so that ( k , l ) = (10,9), ( This is the case in which six resource elements 1010d, which are 10, 10, (4, 9), (4, 10), (5, 9), and (5, 10), are used. This means that a transmitter with four antenna ports has one or two antenna ports through ( k , l ) = (10,9), (10,10), (4,9), (4,10). The transmitting end corresponds to the case of transmitting the CSI-RS through ( k , l ) = (5,9) and (5,10). Based on k ´ = 10, k = k ´-0 for p = 15,16, k = k ´-6 for p = 17,18 and k = k ´- for p = 19,20 It becomes five. This pattern will be referred to as a D pattern.

For the normal CP, referring to Table 1, eight CSI-RS patterns are possible for eight antenna ports, and referring to FIGS. 10A to 10D, six for each of the CSI-RS patterns of eight antenna ports. Since four CSI-RS patterns for the antenna ports are A to D, 32 (= 8 * 4) CSI-RS patterns may be possible for all six antenna ports.

11A to 11D illustrate a case in which two resource elements are removed from eight resource elements for eight antenna ports in the case of an extended CP. 11A to 11D, the horizontal axis represents a symbol (time), the vertical axis represents a subcarrier (frequency), "1102" shows a control region, "1104" shows a region where the CRS is transmitted, and "1106". "Shows the area where the DM-RS is transmitted.

As an example, FIGS. 11A through 11D illustrate a case in which eight antenna ports are used in an extended CP, and the CSI-RS pattern information in Table 2 is zero. If the CSI-RS pattern information is 0,

= (11,4) and n _s mod2 = 0 (first slot), so in the subframe ( k , l ) = (11,4), (11,5), (8,4), (8,5) Resource element 1108, which is (5,4), (5,5), (2,4), (2,5), is set for CSI-RS for eight antenna ports.

11A shows that two resource elements ((2,4), (2,5)) having the lowest k values among the eight resource elements 1108 are omitted so that ( k , l ) = (11,4) in the subframe. In this case, six resource elements 1110a, which are (11,5), (8,4), (8,5), (5,4), and (5,5), are used. This is the case when the transmitter having four antenna ports transmits CSI-RS through ( k , l ) = (11,4), (11,5), (8,4), (8,5) In addition, a transmission terminal having one or two antenna ports corresponds to a case of transmitting CSI-RS through ( k , l ) = (5,4) and (5,5). 'when based on a = 11, p = 15,16 days if k = k' k-0, p = 17,18 days if k = k '-3, p = 19, 20, if one k = k'- 6, which is the same as Equation 1 above. This pattern will be referred to as an A pattern.

11B shows that two resource elements ((8,4), (8,5)) having the second highest k value among the eight resource elements 1108 are omitted so that ( k , l ) = (11 in the subframe. It is the case that six resource elements 1110b are used, which are (4), (11,5), (5,4), (5,5), (2,4), and (2,5). This is the case when the transmitter having four antenna ports transmits CSI-RS through ( k , l ) = (5,4), (5,5), (2,4), (2,5) In addition, a transmission terminal having one or two antenna ports corresponds to a case of transmitting the CSI-RS through ( k , l ) = (11,4) and (11,5). Based on k ´ = 5, for p = 15,16 k = k ´-0, for p = 17,18 k = k ´-3 and for p = 19,20 k = k ´ + 6 becomes. This pattern will be referred to as a B pattern.

11C shows that two resource elements ((5,4), (5,5)) having the second lowest k value among the eight resource elements 1108 are omitted so that ( k , l ) = (11) in the subframe. In this case, six resource elements 1110c are used, i.e., (4), (11,5), (8,4), (8,5), (2,4), and (2,5). This means that a transmitter with four antenna ports has one or two antenna ports through ( k , l ) = (11,4), (11,5), (8,4), (8,5). The transmitting end corresponds to the case of transmitting the CSI-RS through ( k , l ) = (2, 4) and (2, 5). 'when based on a = 11, p = 15,16 days if k = k' k-0, p = 17,18 days if k = k '-3, p = 19, 20, if one k = k'- 9 becomes. This pattern is called a C pattern.

11D shows that two resource elements ((11,4) and (11,5) having the highest k values among the eight resource elements 1108 are omitted so that ( k , l ) = (8,4) in the subframe. In this case, six resource elements 1110d are used. This means that a transmitter with four antenna ports has one or two antenna ports through ( k , l ) = (5,4), (5,5), (2,4), (2,5) The transmitting end corresponds to the case of transmitting the CSI-RS through ( k , l ) = (8, 4) and (8, 5). Based on k ´ = 5, for p = 15,16 k = k ´-0, for p = 17,18 k = k ´-3 and for p = 19,20 k = k ´ + 9 becomes. This pattern will be referred to as a D pattern.

For the extended CP, with reference to Table 2, seven CSI-RS patterns are possible for eight antenna ports, and with reference to FIGS. 11A through 11D, six for each of the CSI-RS patterns of eight antenna ports. Since four CSI-RS patterns for the antenna ports may be A to D, 28 (= 7 * 4) CSI-RS patterns may be possible for all six antenna ports.

10A to 10D and 11A to 11D described above are examples, and various methods capable of setting six resource elements are applicable.

For the case where the CSI-RS is transmitted through 6 resource elements, the case where the number of CSI-RS antenna ports of one transmitting end is 4 and the number of CSI-RS antenna ports of the other transmitting end is 1 or 2 Although described, the number of CSI-RS antenna ports of three transmission stages may be one or two.

Meanwhile, in Table 1 and Table 2, empty spaces remain when there are four or eight antenna ports. In Table 1, out of the 32 values indicated by the 5-bit bit value for 4 antenna ports, only 16 are allocated for the CSI-RS pattern, 16 are empty, and 5 bit values for 8 antenna ports. Of these 32 values, only eight are allocated for the CSI-RS pattern and 24 are empty. Thus, in Table 1 as a whole, 40 empty spaces remain unused in the case of four antenna ports and eight antenna ports. In Table 2, as in Table 1, some values are not used when the number of antenna ports is four and eight among the 32 values indicated by the 5-bit bit value.

According to an embodiment of the present invention, the information on the CSI-RS pattern in case of using six antenna ports in the remaining space not used in Table 1 and Table 2 is allocated. Tables 3 and 4 are examples of tables that map the settings for the CSI-RS pattern in the case of six antenna ports to Table 1 (normal CP) and Table 2 (extended CP), respectively.

[Table 3]

[Table 4]

In Table 3 and Table 4

Is information about the location of one specific resource element of the CSI-RS pattern. In a subframe in which the CSI-RS is set to be transmitted, the CSI-RS sequence (

) Is an orthogonal sequence (

And then complex-valued symbols (

).

&Quot; (2) "

where

Tables 3, 4, and Equation 2 are just examples, and various methods may be used.

Referring to Table 3, in the case of normal CP, A, B, C, and D patterns corresponding to the CSI-RS pattern of the 6 antenna ports that can be expressed from the CSI-RS patterns of the 8 antenna ports are respectively CSI reference. signal configuration 10 ~ 14 & 26 ~ 28 (4 or 6 CSI reference signals), CSI reference signal configuration 15 ~ 19 & 29 ~ 31 (4 or 6 CSI reference signals), CSI reference signal configuration 5 ~ 9 & 23 ~ 25 (6 or 8 CSI reference signals ), And CSI reference signal configuration 10-14 & 26-28 (6 or 8 CSI reference signals).

Referring to Table 4, in the case of the extended CP, A, B, C, and D patterns corresponding to the CSI-RS pattern of the 6 antenna ports that can be expressed from the CSI-RS pattern of each 8 antenna ports are the CSI reference, respectively. signal configuration 8 ~ 11 & 22 ~ 24 (4 or 6 CSI reference signals), CSI reference signal configuration 12 ~ 15 & 25 ~ 27 (4 or 6 CSI reference signals), CSI reference signal configuration 4 ~ 7 & 19 ~ 21 (6 or 8 CSI reference signals ), And CSI reference signal configuration 8-11 & 22-24 (6 or 8 reference signals).

Here, '4 or 6 CSI reference signal' corresponds to '4 CSI reference signal' in Table 1 and Table 2, and '6 or 8 reference signal' corresponds to '8 CSI reference signal' in Table 1 and Table 2. . That is, in Table 1 and Table 2, when the 2-bit value indicating the number of CSI-RS antenna ports is 00, the number of antenna ports is 1, when 01 is 2, and the number of antenna ports is 10. Is 4 and 11, when the number of antenna ports is 8, in Tables 3 and 4, when the 2-bit value for indicating the number of CSI-RS antenna ports is 00, the number of antenna ports is 1 and when it is 01, When the number of antenna ports is two, the number of antenna ports is four or six when 10, and the number of antenna ports is six or eight when eleven.

Therefore, if it was possible to know whether the number of antenna ports directly used is 1, 2, 4 or 8 through the 2-bit bit value of the number of antenna ports, the above-described method using Table 3 or Table 4 is used. In the embodiment, whether the number of antenna ports used is one or two can be known as a 2-bit bit value as before, but whether it is four, eight, or six additionally configured two bits Along with the value, it can be known from the 5-bit bit value associated with the CSI-RS pattern information (this is the CSI reference signal configuration of Tables 3 and 4).

In Equation 2, 'CSI reference signal configuration 15 ~ 19 & 29 ~ 31, 4 or 6 CSI reference signals, and normal cyclic prefix' is B pattern of normal CP at 6 antenna ports, 'CSI reference signal configuration 5 ~ 9 & 23 ~ 25 , 6 or 8 CSI reference signals, and normal cyclic prefix 'is the C pattern of the normal CP at the six antenna ports, and' CSI reference signal configuration 10 ~ 14 & 26 ~ 28, 6 or 8 CSI reference signals, and normal cyclic prefix 'is 6 The D pattern of the normal CP at the four antenna ports, 'CSI reference signal configuration 12 ~ 15 & 25 ~ 37, 4 or 6 CSI reference signals, and extended cyclic prefix' is the B pattern of the extended CP at the six antenna ports, 'CSI reference signal configuration 4 ~ 7 & 19 ~ 21, 6 or 8 CSI reference signals, and extended cyclic prefix 'is the C pattern of the extended CP at 6 antenna ports,' CSI reference signal configuration 8 ~ 11 & 22 ~ 24, 6 or 8 CSI reference signals, and extended cyclic prefix 'is the D pattern of the extended CP on all six antenna ports, and all other CSI re The ference signal configurations apply for the 1, 2, 4, 8 antenna ports and for the A pattern at the 6 antenna ports.

Equations 2, Tables 3, and 4 described above are not limited within the limits of maintaining the meanings, and may be expressed in other ways. That is, the positions of each CSI-RS configuration in Tables 3 and 4 may be arranged in various ways.

On the other hand, Tables 3 and 4 above include all possible cases (A to D patterns) for the number of six antenna ports, but generate a table containing only fewer patterns (for example, A patterns only). It would also be possible.

In other words, if all possible cases (A to D patterns) are included for the number of 6 antenna ports, the normal CP uses a table in which 32 cases are added in Table 1 (for example, Table 3). In CP, 28 cases are added in Table 2 (for example, Table 4). In addition, in Equation 1, some equations are added to use Equation (for example, Equation 2).

If a specific pattern (for example, A pattern only) is included for the number of 6 antenna ports, the normal CP uses a table in which 8 additional cases are added (for example, Table 5). In the extended CP, seven additional cases in Table 2 are used (for example, Table 6). Equation 1 can be used as it is. In this case, if the number of antenna ports directly used is 1, 2, 4, or 8, the number of antenna ports used in the case is known through the 2-bit bit value of the number of antenna ports. Is 1, 2, or 4, it can be known as a bit value of 2 bits as in the past, but 8 or 6 additionally configured CSI-RS pattern information with a bit value of 2 bits This can be seen from the 5-bit bit value associated with. For example, in Table 5, if 11 is received as a 2-bit bit value for the number of antenna ports, the number of antenna ports used is 6 or 8, wherein 5 bits related to CSI-RS pattern information are used. If the decimal value of the bit value (this is the CSI-RS configuration in Table 5) is 0 to 4 or 20 to 22, the number of antennas is 8, and the value is 5 to 9 or 23 to 25. In this case, the number of antennas is six.

[Table 5]

TABLE 6

According to another embodiment of the present invention, the CSI-RS configuration may transmit a maximum of one configuration to each terminal 510 of a corresponding cell, and the configured information is a period of CSI-RS transmission. And 8-bit information about offset, 2-bit information about whether the number of CSI-RS antenna ports is 1, 2, 4, 8, and CSI-RS configurable for each CSI-RS antenna port number as shown in Table 1 and Table 2 It may include 5-bit information about the pattern.

In addition, in the present embodiment, the CSI-RS configuration transmitted to the terminal 510 is 2-bit information indicating four patterns A, B, C, and D as described with reference to FIGS. 10A to 10D and 11A to 10D. It may further include. In the six antenna ports, the CSI-RS pattern may be represented as two resource elements missing from the eight resource elements for the conventional CSI-RS pattern of each of the eight antenna ports (Table 1 or Table 2). In this case, the number of cases is 4 (A to D) and may be composed of 2 bits.

That is, 8-bit information on the period and offset of the CSI-RS transmission, 2-bit information on whether the number of CSI-RS antenna ports is 1, 2, 4, 8 ('11' is transmitted for 8 antenna ports), In addition to 5-bit information on the CSI-RS pattern configurable for each CSI-RS antenna port number shown in Table 1 and Table 2, a 2-bit signal designating one of the A to D patterns is transmitted.

On the other hand, when the 2-bit signal designating one of the A to D pattern is not transmitted, the number of antenna ports may be set to 8.

Alternatively, a 1-bit signal indicating whether the number of antenna ports is 6 or 8 may be added. When the number of antenna ports is 6, which of the A to D patterns may be used in advance. When the 2-bit information on the number of CSI-RS antenna ports is set to '11' which designates 8 antenna ports, the number of antenna ports is 6 or 8 according to the 1-bit information indicating whether the number of antenna ports is 6 or 8. It is determined as 8, and if the number of antenna ports is 6, it is promised in advance which pattern to follow.

Alternatively, the CSI-RS pattern in the six antenna ports may be configured in such a manner that two resource elements are added to four resource elements for the CSI-RS pattern of each of the existing four antenna ports (of Table 1 or Table 2). And the number of cases for this may consist of 2 bits.

That is, 8 bits of information about the period and offset of the CSI-RS transmission, 2 bits of information about whether the number of CSI-RS antenna ports is 1, 2, 4, 8 ('10' is transmitted in case of 4 antenna ports), In addition to 5-bit information on the CSI-RS pattern configurable for each CSI-RS antenna port number as shown in Table 1 and Table 2, a 2-bit signal designating a pattern is transmitted.

For example, in a normal CP, when the 2-bit signal designating a pattern is "00", when k = k ´-1 (corresponding to the A pattern of FIG. 10A) when p = 19,20, and when "01" When p = 19,20 k = k ´ + 1 (corresponds to the B pattern in FIG. 10B), and when “10”, k = k ”-7 when p = 19,20 (in the C pattern of FIG. 10C). It corresponds), and when "11", the day p = 19,20 may be a k = k '-5 (corresponding to D pattern in FIG. 10d).

For example, in the extended CP, when the 2-bit signal designating the pattern is "00", when k = k ´-6 (corresponding to the A pattern of FIG. 11A) when p = 19,20, and when “01” When p = 19,20 k = k ´ + 6 (corresponds to the B pattern in FIG. 11B), and when “10”, k = k ´-9 when p = 19,20 (with C pattern in FIG. 11C). In the case of “11”, k = k ′ + 3 when p = 19,20 (corresponding to D pattern of FIG. 11D).

On the other hand, when the 2-bit signal designating the pattern is not transmitted, the number of antenna ports may be set to 4.

Alternatively, a 1-bit signal indicating whether the number of antenna ports is 4 or 6 may be added. When the number of antenna ports is 6, which two resource elements are added to four resource elements may be limited in advance. When the 2-bit information on the number of CSI-RS antenna ports is set to '10' which designates four antenna ports, the number of antenna ports is 4 or 6 according to the 1-bit information indicating whether the number of antenna ports is 4 or 6. It is determined as 6, and if the number of antenna ports is 6, what pattern to follow is promised in advance.

Although one or two bit information is described as being added for the case of six antenna ports, the present invention is not limited thereto, and other sizes of information may be added as necessary. For example, 1 bit is added to indicate the case of using 6 antenna ports, and the above-mentioned for specifying what pattern is actually used when instructed to use 6 antenna ports by the additional 1 bit. A total of three bits of information may be added by adding two bits of information as described above.

According to another embodiment of the present invention, one transmitting end transmits CSI-RS through four antenna ports, and the other transmitting end transmits CSI-RS through one or two antenna ports, so that all six When two resource elements are used for CSI-RS transmission, two CSI-RS antenna port number information and two CSI-RS pattern information may be transmitted to the terminal to signal this.

That is, two bits indicating the number of CSI-RS antenna ports and CSI-RS for each transmitting end transmitting CSI-RS through four antenna ports and transmitting end transmitting CSI-RS through one or two antenna ports. Transmit 5 bits representing the RS pattern.

This method has the advantage of maintaining the configuration method and the signaling method for the CSI-RS pattern, such as Table 1, Table 2 and Equation (1).

However, each UE may violate the existing rule that at most one CSI-RS configuration may be transmitted.

In addition, compared to the system shown in FIG. 1 (when a terminal receives downlink data from one transmitter, that is, when one transmitter transmits CSI-RS), 7 bits (antenna) for CSI-RS configuration 2 bits for indicating the number of ports, and 5 bits for indicating the CSI-RS pattern that can be configured for each antenna port number).

In addition, an additional bit may need to be configured to indicate how many CSI-RS configuration information the UE should receive. For example, if the additional bit is 1 bit, and the bit value is 0, the CSI-RS configuration may be one CSI-RS configuration as before, and the bit value of 1 may indicate that the CSI-RS configuration is two. .

If up to N CSI-RS configurations can be indicated, each 7 bits (2 bits for indicating the number of antenna ports, each antenna port for (N-1) CSI-RS configurations to the existing 7 bits 5 bits for indicating a CSI-RS pattern that can be configured for the number), that is, (N-1) * 7 bits as a whole may be added. In addition, separately to indicate how many CSI-RS configurations

Bits can be added. In this case, the maximum number N may be predefined in the system.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims

A CSI-RS setting unit which transmits a downlink signal to a terminal and sets configuration information of a channel status information reference signal (CSI-RS) transmitted from a plurality of transmitting terminals having the same cell ID;
An interface for transmitting CSI-RS configuration information transmitted from another transmitting end among the CSI-RS configuration information set by the CSI-RS setting unit to the other transmitting end; And
It includes a transmitter for transmitting the CSI-RS configuration information set by the CSI-RS configuration unit to the terminal,
The CSI-RS configuration information includes information on resource elements through which the CSI-RS is transmitted when the number of CSI-RS antenna ports is five or six.

The method of claim 1,
When the number of the CSI-RS antenna ports is 6, the resource elements in which the CSI-RSs are transmitted include one subframe in the time domain and one resource block in the frequency domain. And if the number of CSI-RS antenna ports is 8 in the made time-frequency resource region, two resource elements are removed from the resource element to which the CSI-RS is transmitted.

The method of claim 1,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. If the number of ports is four, characterized in that two resource elements are added to the resource element to which the CSI-RS is transmitted.

The method of claim 1,
The CSI-RS configuration information includes CSI-RS configurations for a case where the number of CSI-RS antenna ports is six in a table that maps CSI-RS configuration to resource elements.

The method of claim 4, wherein
The CSI-RS configuration for the case where the number of the CSI-RS antenna ports is six in the table is included in the group of four or eight CSI-RS antenna ports.

The method of claim 1,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to eight. And a information indicating whether or not it is six or eight.

The method according to claim 6,
The information indicating whether the number of CSI-RS antenna ports is 6 or 8 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. In the case of 8, the transmission end, characterized in that it includes information indicating which of the six resource elements of the eight resource elements to which the CSI-RS is transmitted when the number of the CSI-RS antenna port is six.

The method of claim 1,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to four. A transmission stage comprising information indicating whether 4 or 6;

The method of claim 8,
The information indicating whether the number of CSI-RS antenna ports is 4 or 6 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. 4, the CSI-RS transmission information comprising the information indicating which two resource elements are added to the four resource elements to be transmitted is used when the number of CSI-RS antenna ports is six.

The method of claim 1,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8 for each transmitting end, and the CSI-RS according to the number of CSI-RS antenna ports for each transmitting end. Transmitting step characterized in that it includes information on the resource element to which the RS is transmitted.

The method of claim 1,
The transmitting end of one of the plurality of transmission stages is characterized in that the number of four CSI-RS antenna ports and the other one is one or two CSI-RS antenna ports.

Transmitting configuration information of a channel status information reference signal (CSI-RS) transmitted from a plurality of transmitting terminals having the same cell ID and transmitting a downlink signal to the terminal;
Transmitting configuration information of the CSI-RS transmitted from another transmitting end of the CSI-RS configuration information to the other transmitting end; And
Transmitting CSI-RS configuration information to the terminal;
The CSI-RS configuration information includes a channel state information reference signal configuration signaling method of a transmitter, characterized in that the information on the resource element to which the CSI-RS is transmitted when the number of CSI-RS antenna ports is 5 or 6.

13. The method of claim 12,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. If the number of ports is 8, the channel state information reference signal configuration signaling method of the transmitting end, characterized in that the two resource elements are removed from the resource element is transmitted CSI-RS.

13. The method of claim 12,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. 4. The method of claim 4, wherein two resource elements are added to a resource element through which the CSI-RS is transmitted when the number of ports is four.

13. The method of claim 12,
The CSI-RS configuration information includes CSI-RS configurations for a case where the number of CSI-RS antenna ports is six in the table for mapping the CSI-RS configuration to resource elements. Signal Configuration Signaling Method.

The method of claim 15,
In the table, the CSI-RS configurations for the case where the number of the CSI-RS antenna ports is six are included in the group when the number of the CSI-RS antenna ports is four or eight. Information reference signal configuration signaling method.

13. The method of claim 12,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to eight. And a channel state information reference signal configuration signaling method of a transmitting end, characterized by including information indicating whether 6 or 8.

The method of claim 17,
The information indicating whether the number of CSI-RS antenna ports is 6 or 8 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. In case of eight, the channel state information of the transmitting end comprises information indicating which six resource elements among the eight resource elements to which the CSI-RS is transmitted are used when the number of CSI-RS antenna ports is six. Reference signal configuration signaling method.

13. The method of claim 12,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to four. And a channel state information reference signal configuration signaling method of a transmitting end, characterized by including information indicating whether 4 or 6.

The method of claim 19,
The information indicating whether the number of CSI-RS antenna ports is 4 or 6 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. In the case of four, the channel of the transmitting end comprising information indicating which two resource elements are added to the four resource elements through which the CSI-RS is transmitted and used when the number of CSI-RS antenna ports is six. State information reference signal configuration signaling method.

13. The method of claim 12,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8 for each transmitting end, and the CSI-RS according to the number of CSI-RS antenna ports for each transmitting end. And a channel state information reference signal configuration signaling method of a transmitting end, comprising information indicating an RS pattern.

13. The method of claim 12,
One of the plurality of transmission stages has one CSI-RS antenna port number of four, and the other one has one or two CSI-RS antenna port numbers. Signal Configuration Signaling Method.

Receives channel status information reference signal (CSI-RS) configuration information transmitted from a plurality of transmitters having the same cell ID, and transmits from the plurality of transmitters based on the CSI-RS configuration information A transceiver for receiving the CSI-RS and transmitting the estimated channel state information based on the received CSI-RS; And
A feedback unit for inferring the channel state information based on the CSI-RS,
The CSI-RS configuration information, the terminal characterized in that it includes information on the resource element to which the CSI-RS is transmitted when the number of CSI-RS antenna ports is 5 or 6.

24. The method of claim 23,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. If the number of ports is 8, characterized in that two resource elements are removed from the resource element to which the CSI-RS is transmitted.

24. The method of claim 23,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. If the number of ports is four, characterized in that two resource elements are added to the resource element to which the CSI-RS is transmitted.

24. The method of claim 23,
The CSI-RS configuration information includes CSI-RS configurations for a case where the number of CSI-RS antenna ports is 6 in a table for mapping the CSI-RS configuration to resource elements.

The method of claim 26,
The CSI-RS configurations for the case where the number of the CSI-RS antenna ports is 6 in the table are included in the group when the number of the CSI-RS antenna ports is four or eight.

24. The method of claim 23,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to eight. And a terminal indicating information indicating whether 6 or 8.

24. The method of claim 23,
The information indicating whether the number of CSI-RS antenna ports is 6 or 8 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. In case of eight, the terminal comprising information indicating which six resource elements of the eight resource elements to which the CSI-RS is transmitted is used when the number of CSI-RS antenna ports is six.

24. The method of claim 23,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to four. Terminal comprising the information indicating whether 4 or 6.

31. The method of claim 30,
The information indicating whether the number of CSI-RS antenna ports is 4 or 6 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. 4, the terminal comprising information indicating which two resource elements are added to the four resource elements through which the CSI-RS is transmitted and used when the number of CSI-RS antenna ports is six.

24. The method of claim 23,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8 for each transmitting end, and the CSI-RS according to the number of CSI-RS antenna ports for each transmitting end. Terminal characterized in that it contains information on the resource element to which the RS is transmitted.

24. The method of claim 23,
The terminal of one of the plurality of transmission terminals is characterized in that the number of four CSI-RS antenna ports and the other one is one or two CSI-RS antenna ports.

Receiving channel status information reference signal (CSI-RS) configuration information transmitted from a plurality of transmitters having the same cell ID;
Receiving CSI-RSs transmitted from the plurality of transmitters based on the CSI-RS configuration information;
Inferring channel state information based on the CSI-RS; And
Transmitting the channel state information;
The CSI-RS configuration information includes the channel state information reporting method of a terminal when the number of CSI-RS antenna ports is 5 or 6, including information on resource elements through which the CSI-RS is transmitted.

35. The method of claim 34,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. If the number of ports is 8, the channel state information reporting method of the terminal, characterized in that the two resource elements are removed from the resource element is transmitted CSI-RS.

35. The method of claim 34,
When the number of CSI-RS antenna ports is 6, the resource element to which the CSI-RS is transmitted is a CSI-RS antenna in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. If the number of ports is 4, the channel state information reporting method of the terminal, characterized in that two resource elements are added to the resource element to which the CSI-RS is transmitted.

35. The method of claim 34,
The CSI-RS configuration information includes CSI-RS configurations for a case where the number of CSI-RS antenna ports is 6 in a table for mapping the CSI-RS configuration to resource elements. .

39. The method of claim 37,
In the table, the CSI-RS configurations for the case where the number of the CSI-RS antenna ports is six are included in a group in which the number of the CSI-RS antenna ports is four or eight. How to report.

35. The method of claim 34,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to eight. Method for reporting channel state information of a terminal, characterized in that it comprises information indicating whether 6 or 8.

35. The method of claim 34,
The information indicating whether the number of CSI-RS antenna ports is 6 or 8 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. In the case of 8, the channel state information report of the terminal comprising information indicating which 6 resource elements of the 8 resource elements to which the CSI-RS is transmitted are used when the number of CSI-RS antenna ports is 6 Way.

35. The method of claim 34,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8, and the number of CSI-RS antenna ports is set when the number of CSI-RS antenna ports is set to four. Method for reporting channel state information of a terminal, characterized in that it comprises information indicating whether 4 or 6.

42. The method of claim 41,
The information indicating whether the number of CSI-RS antenna ports is 4 or 6 may include the number of CSI-RS antenna ports in a time-frequency resource region including one subframe on a time axis and one resource block on a frequency axis. In the case of four, the channel state of the terminal, characterized in that it includes information indicating which two resource elements are added to the four resource elements to which the CSI-RS is transmitted to be used when the number of CSI-RS antenna ports is six How to report information.

35. The method of claim 34,
The CSI-RS configuration information includes information indicating whether the number of CSI-RS antenna ports is 1, 2, 4, or 8 for each transmitting end, and the CSI-RS according to the number of CSI-RS antenna ports for each transmitting end. Method for reporting channel state information of a terminal, characterized in that it includes information on the resource element to which the RS is transmitted.

35. The method of claim 34,
The method of reporting channel state information of a terminal, characterized in that one of the plurality of transmission terminals has four CSI-RS antenna ports and another one has one or two CSI-RS antenna ports. .