KR102102095B1 - Apparatus and Method for Transmitting Reference Signal, Channel Estimation Apparatus and Method using the same - Google Patents

Abstract

The present invention relates to a reference signal (RS) transmission apparatus and method in a wireless communication system, and a channel estimation method and apparatus using the same.
According to a communication environment such as CoMP and MU-MIMO, one of the same reference signal sequences and different reference signal sequences are selectively used for each UE or transmission point (TP) for each UE. Step of generating a reference signal and transmitting it to the terminal, and a selection instruction on whether the reference signal sequence for the transmitted reference signal is the same reference signal sequence or a different reference signal sequence for each UE or transmission point (TP) And generating and transmitting the information to the corresponding terminal.
In a communication system in which CoMP and / or MU-MIMO is supported, a channel may be estimated by transmitting a reference signal from the same or different reference signal sequence for each UE or transmission point (TP) according to the environment in which the terminal is placed.

Description

Reference signal transmission method and device, and channel estimation method and device using same {Apparatus and Method for Transmitting Reference Signal, Channel Estimation Apparatus and Method using the same}

The present invention relates to wireless communication, and more particularly, to a method and apparatus for transmitting a reference signal in a wireless communication system, and a channel estimation method and apparatus using the same.

With the development of communication systems, consumers such as businesses and individuals have used a wide variety of wireless terminals.

In the current mobile communication system, as a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data beyond voice-oriented services, the development of a technology capable of transmitting large-capacity data equivalent to a wired communication network is only required. Rather, it is essential to have an appropriate error detection method that can improve system performance by minimizing reduction of information loss and improving system transmission efficiency.

In addition, various reference signals are used in various communication systems to provide information on a communication environment to an external device through uplink or downlink.

In addition, multi-cell (or point) cooperation has been introduced to increase the performance and communication capacity of a wireless communication system. Multi-cell (or point) cooperation is also referred to as cooperative multiple point transmission and reception (CoMP). CoMP includes a beam avoidance technique in which adjacent cells (or points) cooperate to mitigate interference to a user at a cell (or point) boundary, and a joint transmission technique in which adjacent cells cooperate and transmit the same data. .

In the next generation wireless communication system such as Institute of Electrical and Electronics Engineers (IEEE) 802.16m or 3rd Generation Partnership Project (3GPP) long term evolution (LTE) -Advanced, performance of users located at the cell boundary and receiving severe interference from adjacent cells To improve this, one of the main requirements is emerging, and CoMP can be considered to solve this problem. Various scenarios are possible for this CoMP.

In addition, as the wireless mobile communication system is considered as development, multi-user multi-input multi-output (MU-MIMO) technology is discussed as well as CoMP, and reference signals are properly distinguished in various communication environments. Or need to be unified.

Accordingly, in the present invention, a specific terminal (User Equipment; hereinafter referred to as 'UE') in various communication environments dynamically switches a reference signal used for channel estimation to be different or the same for each UE or transmission point (TP). In order to do so, I would like to propose a method for signaling necessary information.

An object of the present invention is to provide a method for generating a reference signal and a signal signaling method therefor.

Another object of the present invention is to provide an apparatus and method for generating a reference signal sequence specific to a terminal in a CoMP system.

Another object of the present invention is to provide a method for generating and indicating the same sequence initialization value or generating different sequence initialization values according to a communication environment when generating a downlink reference signal sequence.

Another object of the present invention is to set an initialization value for generating the same sequence for each terminal and an initialization value for generating a different sequence when generating a downlink reference signal in the CoMP system, and then set one of them according to the environment of each terminal. It provides a method of selecting and generating a reference signal.

Another object of the present invention is to set an initialization value for generating the same sequence for each terminal and an initialization value for generating a different sequence when generating a downlink reference signal in the CoMP system, and then set one of them according to the environment of each terminal. It is to provide a method of signaling the indication information (selection indication information) for the selected sequence initialization value to each terminal by generating and transmitting the selected sequence.

In order to achieve the above object, an embodiment of the present invention is a method of transmitting a reference signal to each terminal using a transmission point linked with one or more terminals, wherein the transmission point generates reference signals to be transmitted to each terminal. According to the communication environment of the terminal, generating a reference signal by selectively using one of the same reference signal sequence and a different reference signal sequence for each terminal or transmission point, and transmitting it to the terminal, and the transmitted reference signal is the terminal or It provides a reference signal transmission method comprising the step of generating a selection indication information on whether the generated from the same reference signal sequence or the different reference signal sequence for each transmission point.

According to another embodiment of the present invention, as a method for estimating a channel of a terminal linked with one or more transmission points, the terminal selects selection information and selection instructions for an initialization value of a reference signal sequence for a reference signal transmitted by the transmission point. A method of receiving a reference signal generated and transmitted according to the information, and confirming initialization value generation information for generating a reference signal sequence, and using the identified initialization value generation information, the method indicated by the received selection indication information It provides a method for estimating a channel comprising the step of generating a reference signal and estimating a channel by comparing the generated reference signal with a reference signal received from the transmission point.

According to another embodiment of the present invention, as an apparatus for transmitting a reference signal in association with one or more terminals, an initialization value of a reference signal sequence for a reference signal to be transmitted is different from that of the same reference signal sequence for each UE or transmission point. A selection instruction information generator for generating selection instruction information selectively indicating which of the initialization values of the reference signal sequence, a reference signal generator for generating a downlink reference signal according to the selection instruction information, and the selection instruction information And it provides a reference signal transmission apparatus including a transmission unit for transmitting the generated reference signal to the terminal.

Another embodiment of the present invention, an apparatus for estimating a channel state in association with one or more transmission points, the reference signal receiving unit for receiving a reference signal from the transmission point;

The selection instruction information for selectively indicating whether the initialization value of the reference signal sequence for the reference signal sequence to be transmitted or generated is the initialization value of the same reference signal sequence for each UE or transmission point and initialization of different reference signal sequences are selectively transmitted. A selection instruction information receiving unit received from a point, an initialization value generation information confirmation unit for confirming initialization value generation information for generating or changing an initialization value used for generating a reference signal, and the received selection instruction information and the confirmed initialization value Provided is a channel state estimation apparatus including a reference signal generator for generating a reference signal based on the generated information, and a channel estimator for estimating a channel state by comparing the generated reference signal with the received reference signal.

1 is a block diagram showing a wireless communication system to which the present invention is applied.
FIG. 2 shows an example of cells and / or RRHs forming a CoMP set and UEs transmitting and receiving the cells and / or RRHs.
FIG. 3 shows an environment in which reference signals from respective transmission points TP in FIG. 2 are transmitted to various terminals.
Figure 4 shows the overall flow of the reference signal transmission method according to an embodiment of the present invention.
5 is a flowchart of a method for transmitting a reference signal of a transmission point according to an embodiment of the present invention.
6 shows a flow of a channel estimation method of a terminal according to an embodiment of the present invention.
7 is an internal configuration diagram of an apparatus for generating and transmitting reference signals and information related to reference signal generation according to an embodiment of the present invention.
8 is an internal configuration diagram of a channel estimation apparatus according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the present invention, when it is determined that detailed descriptions of related well-known structures or functions may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to the other component, but another component between each component It should be understood that elements may be "connected", "coupled" or "connected".

The wireless communication system provides various communication services such as voice and packet data.

The wireless communication system includes a user equipment (UE) and a base station (eNodeB; Evolved-Node-B).

In the present specification, the terminal is a term including a mobile station (MS), a user terminal (UT), a subscriber station (SS), and a wireless device.

A base station or eNodeB or cell is a fixed station that performs communication with a terminal, Node-B, Sector, Site, BTS (Base Transceiver System), It may be referred to in other terms, such as an access point (Access Point), a relay node (Relay Node).

The eNodeB should be interpreted in a comprehensive sense indicating some areas or functions covered by a base station controller (BSC) in CDMA and a radio network controller (RNC) in WCDMA. In addition, it may include a coverage area of various cells such as a megacell, macrocell, microcell, picocell, femtocell, and relay node communication range.

Referring to FIG. 1, the wireless communication system 10 is widely deployed to provide various communication services such as voice and packet data. The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service for a specific geographic area or frequency domain, and may be called a site. A site may be divided into a number of areas 15a, 15b, and 15c, which may be called sectors, and each sector may have a different cell ID.

The terminal 12 (mobile station, MS) or UE may be fixed or mobile, and user equipment (UE), mobile terminal (MT), user terminal (UT), subscriber station (SS), wireless device (wireless device) , PDA (personal digital assistant), wireless modem (wireless modem), can be called in other terms, such as handheld devices (handheld device).

Base station 11 generally refers to a station (station) that communicates with the terminal 12, eNodeB (evolved-NodeB), BTS (Base Transceiver System), access point (Access Point), femto base station (Femto eNodeB), home The base station (Home eNodeB: HeNodeB), relay (relay), remote radio head (Remote Radio Head: RRH) can be called in other terms. Cells (15a, 15b, 15c) should be interpreted in a comprehensive sense indicating some areas covered by the base station 11, meaning to cover all the various coverage areas such as megacell, macrocell, microcell, picocell, femtocell to be.

Hereinafter, downlink means a communication or communication path from the base station 11 to the terminal 12, and uplink means a communication or communication path from the terminal 12 to the base station 11. . In the downlink, the transmitter may be part of the base station 11, and the receiver may be part of the terminal 12. In the uplink, the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11. There is no limitation in the multiple access technique applied to the wireless communication system 10. Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA (SC-FDMA), OFDM-FDMA, OFDM-TDMA , OFDM-CDMA can use various multiple access techniques. These modulation techniques demodulate signals received from multiple users of the communication system to increase the capacity of the communication system. For uplink transmission and downlink transmission, a time division duplex (TDD) method that is transmitted using different times or a frequency division duplex (FDD) method that is transmitted using different frequencies may be used.

The wireless communication system 10 may be a CoMP (Coordinated Multi Point) system. CoMP system refers to a communication system supporting CoMP or a communication system to which CoMP is applied. CoMP is a technique for adjusting or combining signals transmitted or received by multi transmission / reception (Tx / Rx) points. CoMP can increase data throughput and provide high quality.

The transmission / reception point may be defined as either a component carrier, a cell, or a base station (macro cell, pico base station (Pico eNodeB), femto base station (Femto eNodeB), etc.), or a remote radio head (RRH). Alternatively, the transmission / reception point may be defined as a set of antenna ports. In addition, the transmission / reception point may transmit information regarding the set of antenna ports to the terminal through radio resource control (RRC) signaling. Therefore, multiple transmission points (TPs) in one cell can be defined as a set of antenna ports. The intersection between the set of antenna ports is always empty.

Each base station or cells can configure multiple transmission / reception points. For example, the multiple transmission / reception points may be macro cells forming a homogeneous network. Further, the multiple transmission / reception points may be macro cells and RRHs having high transmission power. Also, the multiple transmission / reception points may be macro cells and RRHs having low transmission power in the macro cell region.

CoMP system can selectively apply CoMP. The mode in which the CoMP system performs communication using CoMP is referred to as a CoMP mode, and a mode not otherwise referred to as a normal mode or a non-CoMP mode.

The terminal 12 may be a CoMP terminal. The CoMP terminal is a component constituting the CoMP system and performs communication with a CoMP Cooperating Set. The CoMP terminal may operate in the CoMP mode as in the CoMP system or in the normal mode. And the CoMP cooperative set is a set of transmission / reception points that directly or indirectly participates in data transmission in a certain time-frequency resource for the CoMP terminal.

Direct participation in data transmission or reception means that transmission / reception points actually transmit data to or from a CoMP terminal in a corresponding time-frequency resource. Indirect participation in data transmission or reception means that transmission / reception points do not actually transmit data to or receive data from a CoMP terminal in a corresponding time-frequency resource, but contribute to making a decision regarding user scheduling / beamforming. .

The CoMP terminal may simultaneously receive signals from the CoMP cooperation set or simultaneously transmit signals to the CoMP set. At this time, the CoMP system minimizes the interference effect between CoMP cooperation sets by considering the channel environment of each cell constituting the CoMP cooperation set.

When operating the CoMP system, various scenarios are possible. The first CoMP scenario is a CoMP composed of a homogeneous network among a plurality of cells in one base station, and may be referred to as an intra-site CoMP. The second CoMP scenario is a CoMP consisting of a macro cell and a homogeneous network for one or more high-power RRHs. The third CoMP scenario and the fourth CoMP scenario are CoMPs composed of one macro cell and a heterogeneous network for one or more low-power RRHs within a macro cell region. At this time, when the physical cell ID of the RRHs is not the same as the physical cell ID of the macro cell, it corresponds to the third CoMP scenario, and the same case corresponds to the fourth CoMP scenario.

CoMP's scope includes joint processing (JP, hereinafter referred to as 'JP') and cooperative scheduling / beam forming (CS / CB, hereinafter referred to as 'CS / CB'), and JP It is also possible to mix CS / CB with.

In the case of JP, data for the terminal is available at at least one transmission / reception point of the CoMP cooperative set in a certain time-frequency resource. JP includes joint transmission (Joint Transmission: JT, hereinafter referred to as 'JT') and dynamic transmission and reception point selection (DPS, hereinafter referred to as 'DPS').

JT means that data transmission is simultaneously performed from multiple transmission / reception points (multi-points) belonging to a CoMP cooperative set to a terminal or a plurality of terminals in a time-frequency resource. In the case of JT, multiple cells (multiple transmission / reception points) transmitting data for one terminal perform transmission using the same time / frequency resource.

In the case of DPS, data transmission is performed from one transmission / reception point of a CoMP cooperative set in a time-frequency resource. The transmission and reception points may be changed for each subframe in consideration of interference. The transmitted data can be used simultaneously in a plurality of transmission / reception points. DPS includes Dynamic Cell Selection (DCS).

In the case of CS, data is transmitted from one transmission / reception point in a CoMP collaboration set for time-frequency resources, and user scheduling is determined by coordination between points in the corresponding CoMP collaboration set.

In the case of CB, it is also determined by cooperation between transmission / reception points of the corresponding CoMP cooperation set. CB (Coordinated Beamforming) prevents interference that occurs between terminals of a neighboring cell.

The CS / CB may include a semi-static point selection (SSPS) that can be selected and changed by selecting a semi-static point.

As described above, it is also possible to mix JP and CS / CB. For example, some transmission / reception points in the CoMP cooperation set may transmit data to a target terminal according to JP, and other transmission / reception points in the CoMP cooperation set may perform CS / CB.

The transmission / reception point to which the present invention is applied may include a base station, a cell, or an RRH. That is, the base station or RRH may be a transmission / reception point. Meanwhile, a plurality of base stations may be multiple transmission / reception points, or a plurality of RRHs may be multiple transmission / reception points. Of course, the operation of all base stations or RRHs described in the present invention can be equally applied to other types of transmission / reception points.

Meanwhile, control information of a physical layer mapped to a physical downlink control channel (PDCCH) used in the physical layer is referred to as downlink control information (DCI). That is, DCI is transmitted on the PDCCH. The DCI may include an uplink or downlink resource allocation field, an uplink transmission power control command field, a control field for paging, and a control field for indicating a random access response (RA response).

DCI has different uses for different formats, and fields defined in DCI are different. Table 1 shows DCI according to various formats.

[Table 1]

Referring to Table 1, DCI format 0 is uplink scheduling information, format 1 for scheduling of one PDSCH codeword, format 1A for compact scheduling of one PDSCH codeword, and very simple for DL-SCH Format 1C for scheduling, format 2 for PDSCH scheduling in closed-loop spatial multiplexing mode, format 2A for PDSCH scheduling in open-loop spatial multiplexing mode, uplink channel There are formats 3 and 3A for transmission of Transmission Power Control (TPC) commands.

Each field of DCI is sequentially mapped to _n information bits a ₀ to a _n-1 . For example, if DCI is mapped to information bits having a total length of 44 bits, each DCI field is sequentially mapped to a ₀ to a ₄₃ . DCI formats 0, 1A, 3, and 3A may all have the same payload size. DCI format 0 may be referred to as an uplink grant.

In a wireless communication system, it is necessary to estimate an uplink channel or a downlink channel for data transmission / reception, system synchronization acquisition, and channel information feedback. The process of restoring a transmission signal by compensating for distortion of a signal caused by a sudden change in a channel environment is called channel estimation. Also, it is necessary to measure a channel state of a cell (or point) to which the UE belongs or another cell (or point). In general, a reference signal (RS) that is known between a UE and a transmission / reception point is used for channel estimation or channel state measurement.

Since the terminal knows the information of the reference signal, it can estimate the channel based on the received reference signal and compensate the channel value to accurately obtain data transmitted from the transmission / reception point.

The reference signal is generally generated and transmitted from a sequence of reference signals. As a reference signal sequence, one or more of various sequences having excellent correlation characteristics may be used. For example, Constant Amplitude Zero Auto-Correlation (CAZAC) sequences such as Zad (Zadoff-Chu) sequences, or pseudo-noise (PN) sequences such as m-sequences, gold sequences, and Kasami sequences. It can be used as a sequence of the reference signal, in addition, various other sequences with excellent correlation characteristics may be used depending on the system situation. In addition, the reference signal sequence may be used as a cyclic extension or truncation to adjust the length of the sequence, and various such as binary phase shift keying (BPSK) or quadrature phase shift keying (QPSK) It may be modulated in a form and mapped to a resource element (RE).

As a downlink reference signal, a cell-specific reference signal (CRS), a multimedia broadcast and multicast single frequency network (MBSFN) reference signal, and a terminal-specific reference signal (UE-specific RS, or demodulation depending on the use purpose) Signal (also called Demodulation RS), Positioning Reference Signal (PRS), and Channel State Information (CSI) reference signal (CSI-RS).

CRS is a reference signal transmitted to all terminals in a cell and is used for channel estimation. CRS may be transmitted in all downlink subframes in a cell supporting PDSCH transmission.

The terminal-specific reference signal is a reference signal received by a specific terminal or a specific terminal group in a cell. Since the terminal-specific reference signal is mainly used for data demodulation of a specific terminal or a specific terminal group, it may be called a demodulation RS (DMRS).

The MBSFN reference signal is a reference signal for providing a Multimedia Broadcast Multicast Service (MBMS), and the PRS can be used as a reference signal for measuring the position of the terminal.

CSI-RS can be used for estimation of channel state information. CSI-RS is deployed in the frequency domain or time domain. Channel quality information such as a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI) when necessary through estimation of the channel status using CSI-RS As can be reported from the terminal. CSI-RS may be transmitted on one or more antenna ports.

In a CoMP system, multiple cells or transmission / reception points can transmit a reference signal to a terminal.

In this CoMP environment, a method and apparatus for guaranteeing orthogonality of an existing reference signal (RS) defined in a single cell in a plurality of cells or transmission points (TPs) Is being considered. That is, in addition to the existing MIMO environment, considering the above-described CoMP environment, a method / device for generating an integrated reference signal sequence and a signaling method / device for information related to generation of the reference signal sequence are being considered.

FIG. 2 shows an example of cells and / or RRHs forming a CoMP set and UEs transmitting and receiving the cells and / or RRHs.

As illustrated in FIG. 2, UE 0, UE1, UE 2, and UE 3 belong to TP 0, TP 1, TP 2, and TP 3, respectively, and have this as a serving cell or point It may be. For convenience, as illustrated in FIG. 2, TP 0 is a macro cell, TP 1 is RRH 1, TP 2 is RRH 2, and TP 3 is RRH3. In addition, the bandwidth allocated for each UE in the UE 0, UE1, UE 2, and UE 3 is a case where some or all of the bandwidth allocated for other UEs are shared with each other on a frequency.

Meanwhile, in a wireless communication system such as LTE, when a reference signal such as DM-RS is transmitted from each cell to the UE, a sequence of reference signals is generated as shown in Equation 1 below, and this is a RE (resource element) mapping ( mapping) and generate a signal to transmit to each UE.

[Equation 1]

은 복소 평면상에서 실수 축과 허수 축 각각에서 PN 시퀀스(

및

)로부터 생성되며, 상기 PN 시퀀스의 초기화 값인

는 슬롯 넘버(

), 셀 아이디(

), 스크램블링 코드 식별자(Scrambling Code Identity,

또는 SCID) 값에 따라 서로 다른 값을 가질 수 있다.Reference signal sequence of Equation 1

Is the PN sequence on the real and imaginary axes on the complex plane (

And

), Which is the initialization value of the PN sequence.

Is the slot number (

), Cell ID (

), Scrambling Code Identity,

Or, it may have different values depending on the SCID) value.

)는 안테나 포트 7 및/또는 8을 사용할 수 있는 DCI 포맷 2B의 경우, 스크램블링 식별자(Scrambling identity)에 관한 1비트 정보를 이용하여 지시된다. 또한 안테나 포트 7, 8, 9, 10, 11, 12, 13 및/또는 14를 사용할 수 있는 DCI 포맷 2C의 경우, DCI 포맷 2C에 포함되는 안테나 포트, 스크램블링 식별자 및 레이어 개수(Antenna port(s), scrambling identity and number of layers)에 관한 아래 표 2와 같은 3비트 정보를 이용하여 지시된다. 즉 표 2에서 보는 것과 같이, DCI 포맷 2C에서는 안테나 포트 7 및/또는 8에 대해서는 SCID가 0 또는 1이며, 나머지 안테나 포트들에 대해서는 항상 0이다.In Equation 1, SCID (Scrambling Code Identity,

) Is indicated using 1-bit information regarding a scrambling identity in case of DCI format 2B in which antenna ports 7 and / or 8 can be used. In addition, in the case of DCI format 2C that can use antenna ports 7, 8, 9, 10, 11, 12, 13, and / or 14, the antenna port, scrambling identifier, and number of layers included in DCI format 2C (Antenna port (s) , scrambling identity and number of layers). That is, as shown in Table 2, in DCI format 2C, SCID is 0 or 1 for antenna ports 7 and / or 8, and is always 0 for the remaining antenna ports.

[Table 2]

At this time, since the current method of generating a reference signal sequence as in Equation 1 is defined in a specific manner for a single cell, orthogonality between reference signals in an environment in which multiple cells or points such as a CoMP environment are considered. Problems may arise.

FIG. 3 shows an environment in which reference signals from respective transmission points TP in FIG. 2 are transmitted to various terminals.

As shown in FIG. 3, the macro cell TP0 transmits a reference signal to UE 0 and UE 1 on the same time-frequency resource (thus, it can be seen as an example of MU-MIMO), and simultaneously transmits to UE0 and UE1 on time-frequency resource. In order to distinguish the two reference signals ⓜ-ⓞ and ⓜ-①, the two reference signals ⓜ-ⓞ and ⓜ-① use the same reference signal sequence, orthogonal sequence such as orthogonal cover code (OCC). Can be divided into.

In addition, RRH 1 (TP 1) transmits a reference signal to UE 1, and if UE 1 is a CoMP UE as shown in FIG. 3, not only RRH 1 but also TP 0 corresponding to a macro cell is transmitted as JT (Joint Transmission) CoMP. Reference signals ⓜ-① and ① are simultaneously received on the time-frequency resource. To this end, the two reference signals ⓜ-① and ① also need to use the same reference signal sequence. In summary, the reference signals ⓜ-ⓞ, ⓜ-① and ① illustrated in FIG. 3 need to use the same reference signal sequence.

If MU-MIMO and CoMP are not simultaneously supported in the same time-frequency resource, the three reference signal sequences illustrated in FIG. 3 need not be the same. That is, when only MU-MIMO is supported, only ⓜ-ⓞ and ⓜ-① need to use the same reference signal sequence. When only CoMP is supported, only ⓜ-① and ① need to use the same reference signal sequence.

Meanwhile, as shown in FIG. 3, RRH 2 (TP 2) transmits a reference signal to UE 3 to RRH 3 (TP 3) (in a CoMP environment, signals to UE 2 and UE 3 in RRH 2 and RRH 3, respectively) An example of a method of transmitting DPS or CS / CB may be, but is not limited to). At this time, RRH 2 transmits a reference signal ② to UE 2, but in reality, the reference signal ② may act as interference (②-ⓘ) when viewed from the UE 0 perspective. Similarly, RRH 3 transmits a reference signal ③ to UE 3, but in reality, the reference signal ③ may act as interference (③-ⓘ) when viewed from the perspective of UE 2.

That is, in order to solve the problem of interference (specifically, for example through FIG. 3, interference between ⓜ-ⓞ and ②-ⓘ in UE 0, and interference between ② and ③-ⓘ in UE 2), different reference signal sequences You need to use

Therefore, in a CoMP environment in which not only a single cell but also a plurality of cells or points are considered, transmission points (TPs) (in FIG. 3) that transmit a signal to a specific UE (eg, UE 1 in FIG. 3) For example, TP 0 and TP 1) which simultaneously transmit signals to UE 1 on a time-frequency resource transmit the same reference signal to each other, but signal the specific UE (UE 1 in the example in FIG. 3). The transmission points that do not transmit (in this case, the transmission point transmits a signal to other UEs, for example in FIG. 3, TP 2 and TP 3, respectively, transmitting signals to UE 2 and UE 3) It is necessary to generate different reference signal sequences to generate and transmit reference signals different from the reference signal transmitted to the UE.

That is, in a CoMP environment in which not only a single cell but also multiple cells or points are considered, when transmitting reference signals to each UE in each cell or transmission point (TP), in order to give pseudo orthogonality between the reference signals , It is necessary to generate a different reference signal sequence between the reference signal transmitted from TP 2 (RRH 2) to UE 2 and the reference signal transmitted from TP 3 (RRH 3) to UE 3.

To solve this case, reference signals transmitted from TP 0 (Macro cell) to UE 0 (ⓜ-ⓞ) and reference signals transmitted from TP 0 (Macro cell) and TP 1 (RRH 1) to UE 1 (Ⓜ-① and ①) have the same reference signal sequence, but the reference signals (ⓜ-ⓞ, ⓜ-① and ①) and the reference signal transmitted from TP 2 (RRH 2) to UE 2 (②) And between TP 3 (RRH 3) and the reference signal (3) transmitted to UE 3, it is necessary to have different reference signal sequences in order to give pseudo orthogonality between the reference signals.

As described above, a method for generating a reference signal sequence for transmitting the same or different reference signal sequences to each other in multiple CoMP scenarios is required, which will be described in detail below.

1. When each cell or transmission point (TP) has a different cell ID (for example, CoMP scenario 1/2/3)

1) Algorithm for generating the same sequence of reference signals

Unlike Equation 1, in order to generate the same reference signal sequence even though cell IDs between transmission points are different in consideration of inter-cell orthogonality between reference signals, unlike Equation 1, common cell ID ). For example, in FIG. 3, reference signals transmitted from TP 0 (Macro cell) to UE 0 (ⓜ-ⓞ), TP 0 (Macro cell) and TP 1 (RRH 1) are reference signals transmitted to UE 1 ( Ⓜ-① and ①) must generate a reference signal sequence based on the same cell ID.

If CoMP and MU-MIMO are not supported on the same time-frequency resource at the same time, there is no change from the UE perspective. That is, since it is enough to follow the cell ID of the cell or transmission / reception point to which each UE belongs, it is necessary to separately instruct the UE about the common cell ID. none. Only eNodeB needs to know and generate a sequence based on a common cell ID. That is, the method of generating the reference signal sequence differs only from the viewpoint of the eNodeB.

If CoMP and MU-MIMO are simultaneously supported on the same time-frequency resource, the cell ID of each cell or transmission / reception point to which the UE belongs and the common cell ID are Since it may be different, it is necessary to separately indicate information on a common cell ID to the UE. In this case, the eNodeB may also generate a sequence based on the common cell ID. That is, the situation related to the reference signal sequence from the standpoint of the eNodeB and the UE should be different from the existing one.

2) Algorithm for generating different reference signal sequences

Since the cell IDs between the transmission points are different, it is possible to generate sufficiently different reference signal sequences only by using a cell-specific reference signal sequence generation method such as Equation (1). That is, the situation related to the reference signal sequence does not need to be different from the existing point of view of eNodeB and UE.

Of course, in order to generate different reference signal sequences, it may be further subdivided to generate different reference signal sequences for each UE or transmission point (TP).

2. When each cell or transmission point (TP) has the same cell ID (for example, CoMP scenario 4)

1) Algorithm for generating the same sequence of reference signals

When cell IDs between transmission points are different, in order to generate the same reference signal sequence, the sequence must be generated based on a common cell ID, unlike Equation 1, but CoMP scenario 4 Since the point is a CoMP environment having the same cell ID, the cell ID is a case where a common one is used. Therefore, the cell-specific reference signal sequence generation method as in Equation 1 is sufficient to generate the same reference signal sequence. That is, the situation related to the reference signal sequence does not need to be different from the existing point of view of eNodeB and UE.

2) Algorithm for generating different reference signal sequences

)을 UE 또는 TP 별로 서로 다르게 설정할 수 있으며, 이를 위해 필요한 정보를 초기화 값 생성정보라 정의한다.Since the cell IDs between the transmission points are the same, it is impossible to generate different reference signal sequences only by using the cell-specific reference signal sequence generation method as in Equation (1). Therefore, it is necessary to generate a different reference signal sequence for each UE or TP by modifying the method for generating a reference signal sequence such as Equation (1). At this time, in order to generate different reference signal sequences, the initialization value defined in Equation (1)

) Can be set differently for each UE or TP, and information necessary for this is defined as initialization value generation information.

That is, the initialization value generation information for generating a different reference signal sequence for each UE or TP must be directed to the UE in the TP, and therefore, the situation related to the reference signal sequence in the TP (or eNodeB) and UE needs to be different from the existing one. .

In this way, when generating the reference signal sequence in the above manner and signaling this information to the UE, the reference signal may be generated and signaled to the UE by considering each CoMP scenario environment and the existing single cell environment separately. It would be more effective to use an integrated one generation method and a signaling method.

In consideration of this point in an embodiment of the present invention, a first initialization value (hereinafter referred to as a first initialization value or initialization value A) for generating sequences identical to each other as an initialization value of a sequence used when generating a downlink reference signal sequence ) And a second initialization value (hereinafter referred to as a second initialization value or initialization value B) for generating a different sequence, select one of them according to the situation of each UE, and generate a sequence. It is to propose a method for signaling the indication information related to this selection to the terminal.

Hereinafter, a method for generating an initialization value A (first initialization value) and an initialization value B (second initialization value), and initialization value generation information required for the same will be described.

Initialization values for generating the same sequence (initialization value A or first initialization value)

In general, a cell-specific initialization value used in Equation 1 may be used. In this case, there is no information to be additionally signaled to the UE. That is, in the general communication environment, in which the cell IDs of multiple TPs are not different, such as in CoMP scenario 1/2/3, there is no need for additional initialization value generation information to make the reference signal sequence the same. Therefore, it is initialized to the UE. There is no need to signal value generation information.

)을 구하기 위한 셀 아이디(cell ID;

) 대신에 사용되어야 한다. On the other hand, among the cases in which cell IDs among a plurality of TPs are different, such as CoMP scenario 1/2/3, among others, when MU-MIMO and CoMP are considered at the same time, it is common to represent the entire CoMP set. Cell ID (common cell ID) is the initial value of the equation (1) (

Cell ID to obtain)

) Should be used instead.

At this time, the common cell ID (common cell ID) may be transmitted to the UE in advance through high layer signaling such as RRC. This common cell ID (common cell ID) information may be 9 bits, but is not limited thereto. However, even when a common cell ID is used, in a CoMP scenario 4 or a non-CoMP environment, the common cell ID is a cell or a point to which the UE belongs. Since it is the same as the cell ID, it will be the cell ID of the cell or point to which the UE belongs, even if signaling is not performed separately or signaling is performed.

That is, for the initialization value A, the cell-specific initialization value used in Equation 1 may be used, or a CoMP set-specific initialization value may be used. When a cell-specific initialization value is used, there is no signaling information to be indicated separately, and when a unique initialization value of a CoMP set is used, common cell ID information is used as the initialization value generation information to the UE. It is necessary to signal, and high-layer signaling such as RRC may be used for the signaling.

Initialization values for generating different sequences (initialization value B or second initialization value)

When the cell IDs between the plurality of TPs are the same as in CoMP scenario 4 or the like, since the cell IDs between the transmission points are the same, the initial value of the cell-specific reference signal sequence as in Equation 1 is the same. It is not possible to generate different reference signal sequences. Therefore, it is necessary to generate an initialization value of a different reference signal sequence for each UE or TP by modifying the method for generating a reference signal sequence such as Equation (1). The initialization value generation information capable of generating the changed initialization value should be indicated to the UE.

At this time, when the cell IDs between the plurality of TPs are different, such as CoMP scenario 1/2/3, etc., and in a non-CoMP (non-CoMP) environment, the initial value for generating different sequences is the same as in Equation (1). The initial value of the cell-specific reference signal sequence is sufficient. However, even if a reference signal sequence generation method such as Equation 1 is modified to generate initialization values of different reference signal sequences for each UE or TP, the original purpose is for generating a different sequence, and thus the same can be applied.

)을 생성하기 위한 초기화 값 생성정보로서 수학식 1의 nSCID는 nRNTI 또는 n`SCID로 대체된다.The method of generating an initialization value of a different reference signal sequence for each UE or TP may be one of the following methods, and the initialization value generation information for this is either pre-defined or pre-defined to the UE so that the UE can know it. It may be transmitted by high layer signaling such as RRC. As described below, different initialization values (

As the initialization value generation information for generating), nSCID of Equation 1 is replaced with nRNTI or n`SCID.

Method 1: Using RNTI

An RNTI value can be used by substituting nSCID in Equation 1 (for example, the parameter nSCID in Equation 1 is changed to nRNTI), whereby the sequence initialization value of the reference signal can be set differently for each UE. Based on this, a reference signal sequence is generated, and a RE (resource element) is mapped and a signal is generated and transmitted to each UE.

At this time, since the RNTI may be known by each UE, the initialization value generation information to be signaled is 0 bits.

That is, in the first method, RNTI of each UE is used as initialization value generation information (ie, nSCID is replaced with nRNTI in Equation 1) to generate a different reference signal sequence for each UE, but the UE's RNTI is already It is known that the initialization value generation information does not need to be signaled separately to the UE.

Method 2: Using separate UE-specific information

In the second scheme, UE-specific information that is separately defined as initialization value generation information may be used, and such UE-specific information will be displayed as n` _SCID .

That is, in the second method, a parameter transmitted by high layer signaling such as UE-specific RRC by coping with n _SCID in Equation 1 may be used. For example, the parameter n _SCID is changed to n` <sub>SCID</sub> . At this time, as the UE-specific information set by n` _SCID , bit number N bits (N is a natural number of 1 or more) information may be used, and through this, each of up to 2 ^N UEs simultaneously transmitting a reference signal on a time-frequency can be used. By generating and assigning different reference signal sequences, it is possible to give pseudo orthogonality between the reference signals.

In summary, in the second scheme, N-bit separate UE-specific information is used as initialization value generation information, and the UE-specific information may be transmitted to the UE using RRC signaling or the like.

Method 3: Use separate TP-specific information

In the third method, TP unique information that is separately defined as initialization value generation information may be used, and this TP unique information will be displayed as n` _SCID .

That is, in the third method, a parameter transmitted by high layer signaling such as RRC, which is unique to TP by replacing n _SCID in Equation 1, may be used. For example, the parameter n _SCID is changed to n` <sub>SCID</sub> . At this time, as the TP specific information set by n` _SCID , bit number N bits (N is a natural number of 1 or more) information can be used, and through this, between TPs of up to 2 ^N transmitting reference signals simultaneously on time-frequency. By generating and assigning different reference signal sequences, it is possible to give pseudo orthogonality between the reference signals.

In summary, the third method uses N-bit separate TP-specific information as initialization value generation information, and this TP-specific information can be transmitted to the UE using RRC signaling or the like.

4th method: using CSI-RS antenna port and / or CSI-RS configuration information

In the fourth method, a parameter determined in association with the CSI-RS antenna port and / or CSI-RS configuration information by coping with n _SCID in Equation 1 may be used. That is, the parameter (n` <sub>SCID</sub> ) determined in association with the CSI-RS antenna port and / or CSI-RS configuration information may be used as the initialization value generation information, and the parameter n <sub>SCID</sub> of Equation 1 is changed to n` _SCID Express it as being.

At this time, for example, CSI-RS antenna port information having a value of 15 to 22 or CSI-RS configuration information having a value of 0 to 31 or a parameter derived therefrom may be used as initialization value generation information (n` _SCID ) The example is as follows.

),(or

),

or

)(or

)

Based on this, a sequence of reference signals is generated, mapped to REs, and signals are generated and transmitted to each UE. At this time, since the CSI-RS antenna port and / or CSI-RS configuration information may be already known to each UE through different signaling for CSI-RS, the signaled bit is 0 bits.

That is, in the fourth method, CSI-RS antenna port information or CSI-RS configuration information having a value of 0 to 31 or a parameter derived therefrom is used as initialization value generation information to generate a different reference signal sequence for each UE or TP ( That is, in Equation 1, n _SCID is replaced with n` _SCID ), but since this information is already known by the UE through other signaling, it is not necessary to separately signal initialization value generation information to the UE.

As described above, according to an embodiment of the present invention, one of the same reference signal and different reference signals for each transmission point is selectively selected for each UE or transmission point to be suitable for each terminal according to a communication environment such as CoMP and MU-MIMO. It may include generating and transmitting to the terminal, and generating selection instruction information on whether the transmitted reference signals are the same reference signals or different reference signals for each UE or transmission point, and transmitting the generated reference information to the corresponding terminal. .

 Further, the method may further include generating initialization value generation information capable of changing the sequence initialization value of the generated and transmitted reference signal, and transmitting the generated initialization value to the corresponding terminal. As the initialization value generation information, common cell ID (common) cell ID), RNTI, UE-specific information, TP-specific information, CSI-RS-related parameters, and one or more of these initialization value generation information may be transmitted through higher layer signaling such as RRC.

Meanwhile, the initialization value generation information may not be separately signaled to the UE according to the type of communication system.

In addition, selection indication information on whether the transmitted reference signals are the same reference signals or different reference signals for each UE or transmission point may be implicitly indicated from information included in the DCI format, and DCI information. It may be indicated explicitly by using a separate bit included in.

또는 SCID) 정보가 이용되거나, DCI 포맷 2C에 포함된 안테나 포트, 스크램블링 식별자 및 레이어 개수(Antenna port(s), scrambling identity and number of layers) 정보를 이용하여 지시될 수 있다.When the selection indication information is implicitly indicated, a 1-bit scrambling code identifier included in DCI format 2B (Scrambling Code Identity,

Alternatively, SCID) information may be used, or may be indicated using antenna port (s), scrambling identity and number of layers information included in DCI format 2C.

In addition, when the selection indication information is explicitly indicated, an additional 1-bit additional indication bit may be used in the DCI format, and the antenna port, scrambling identifier, and number of layers newly configured or defined as 4 bits of the DCI format (Antenna port) (s), scrambling identity and number of layers) can be used.

As described above, in one embodiment of the present invention, among the initialization values A and B (initialization values A and B), it is dynamically determined which initialization value to select according to the situation of each UE, and information related to this determination (Selection indication information) may be transmitted to the UE, and at this time, the method of configuring the selection indication information may be one of the following four, but is not limited thereto.

Method 1 for generating selection instruction information: implicit method (use the instruction information related to the existing DM-RS as shown in Table 2)

As shown in Table 2, the method 1 for generating selection instruction information is a method in which the previously defined reference signal instruction information is used as it is, but is implicitly indicated using the reference instruction information.

More specifically, through the SCID value indicated and included in the antenna port, scrambling identifier and layer number (Antenna port (s), scrambling identity and number of layers) information that is 3-bit information of DCI format 2C as shown in Table 2 above. If SCID = 0, 'Initialization value A (initialization value for generating the same reference signal sequence)' is generated, and if SCID = 1, 'Initialization value B (initialization value for generating different reference signal sequences)' is generated. do. Conversely, if SCID = 1, 'initialization value A (initialization value for generating the same reference signal sequence)' is generated, and if SCID = 0, 'initialization value B (initialization value for generating different reference signal sequences)' is generated. You can also create

If Equation 1 is modified by expressing this, Equation 2 is obtained. (Information for transmitting an existing SCID, that is, Table 2, for example, is used as it is)

[Equation 2]

  or

)를 결정하는 값으로는 셀 아이디(

) 및

등이 있으며, 수학식 1과 비교하여, 수학식 2에서 셀 아이디(

)는 앞서 설명한 바와 같이 공통 셀 아이디(common cell ID)가 될 수도 있고 기존 수학식1 과 동일하게 UE가 속한 셀 또는 포인트(point)의 셀 아이디(cell ID)일 수도 있다. 또한 수학식 1의

는 본 발명의 일 실시예에 의한 초기화 값 생성정보인

로 대체될 수 있으며, 기존 시그널링 되는 SCID 값에 따라 초기화 값 A 또는 초기화 값 B를 생성하는 경우에 따라 달리 설정될 수 있다.Sequence initialization value (2)

) Is the value that determines the cell ID (

) And

Etc., and compared to Equation 1, the cell ID in Equation 2 (

) May be a common cell ID as described above, or a cell ID of a cell or a point to which the UE belongs, as in the previous equation (1). Also, Equation 1

Is the initialization value generation information according to an embodiment of the present invention

It may be replaced with, and may be set differently depending on the case of generating an initialization value A or an initialization value B according to an existing signaled SCID value.

는

를 대체하는 파라미터를 의미하나, 동일한 의미와 용도를 가지는 한도 내에서 상기와 같은 방식의 표기에 한정되는 것이 아니라 다른 방식으로 표기할 수도 있을 것이다. (예를 들어,

가 본 발명의 내용을 포함하여서 동일하게 파라미터로 사용될 수도 있을 것이다.)here

The

It means a parameter that replaces, but is not limited to the above-described notation in the same manner and within the limits having the same meaning and use, it may be indicated in other ways. (E.g,

It may also be used as a parameter, including the contents of the present invention.)

), 공통 셀 아이디(common cell ID), RNTI 정보, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등이 될 수 있으며, 그 중에서 단말이 모르고 있는 정보라면 eNodeB가 미리 RRC 시그널링 등을 이용하여 해당 초기화 값 생성정보를 UE에게 전송해 두어야 한다. 본 명세서에서는 초기화 값 생성정보 중에서 RNTI 정보를

로, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등과 같이

와 상이한 값을

로 표현하기로 한다.Meanwhile, as the initialization value generation information used to change to the same initialization value A for each UE or TP or to a different initialization value B to correspond to the selection indication information, the cell ID (

), Common cell ID (common cell ID), RNTI information, UE-specific information defined separately, TP-specific information defined separately, CSI-RS-related parameters, and the like, eNodeB can be used in advance if the UE does not know the information. The corresponding initialization value generation information should be transmitted to the UE using RRC signaling or the like. In this specification, RNTI information among initialization value generation information is used.

With UE-specific information defined separately, TP-specific information defined separately, CSI-RS-related parameters, etc.

And different values

It will be expressed as

Method 2 for generating selection instruction information: explicit method (instruction information related to existing DM-RS shown in Table 2 is used as it is)

As shown in Table 2, in the method 2 for generating selection indication information, the previously defined reference signal indication information is used as it is, but a separate explicit indication bit is used.

In other words, the DCI format includes a separate 1-bit selection indication information. (I.e., in Method 1, if there was no information added to DCI, 1 bit is included in this case). In the case of Method 2, an equation for obtaining the initialization value of Equation 1 may be expressed by Equation 3 and Equation 4 below. Since the formula for r (m), which is the entire sequence, is the same as in Equation 1, expression is omitted.

For reference, Equation 3 indicates that when the 1-bit information additionally included in the DCI format is 0, it is indicated to generate the initialization value A (initialization value for generating the same reference signal sequence) (for example, the bit value). This is 0 (or vice versa 1)), and Equation 4 indicates that 1-bit information additionally included in the DCI format generates an initialization value B (initialization value for generating different reference signal sequences) (eg For example, the bit value corresponds to 1 (or vice versa 0).

[Equation 3]

[Equation 4]

)는 DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 A 또는 제1 초기화 값(서로 동일한 참조신호 시퀀스의 생성을 위한 초기화 값)를 생성하는 것을 지시하는 경우에는 앞서 설명한 바와 같이 공통 셀 아이디(common cell ID)가 될 수도 있고 기존 수학식 1과 동일하게 UE가 속한 셀 또는 포인트(point)의 셀 아이디(cell ID)일 수도 있다. 하지만, DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 B 또는 제2 초기화 값(서로 다른 참조신호 시퀀스의 생성을 위한 초기화 값)를 생성하는 것을 지시하는 경우에는 기존 수학식 1과 동일하게 UE가 속한 셀 또는 포인트(point)의 셀 아이디(cell ID)이다.Compared to Equation 1, the cell ID in Equation 3 and Equation 4 (

) Indicates that the 1-bit information additionally included in the DCI format generates an initialization value A or a first initialization value (initialization value for generating the same reference signal sequence), as described above. It may be a common cell ID) or may be a cell ID of a cell or a point to which the UE belongs, as in Equation 1 above. However, when the 1-bit information additionally included in the DCI format indicates to generate an initialization value B or a second initialization value (initialization value for generating different reference signal sequences), the UE is the same as the existing equation (1). The cell ID of the cell or point to which it belongs.

는 DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 A 또는 제1 초기화 값(서로 동일한 참조신호 시퀀스의 생성을 위한 초기화 값)를 생성하는 것을 지시하는 경우에는 기존 수학식 1과 동일한 방식으로 값이 지정되며, DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 B 또는 제2 초기화 값(서로 다른 참조신호 시퀀스의 생성을 위한 초기화 값)을 생성하는 것을 지시하는 경우에는

로 대체되며 이 값으로는 앞서 설명한 바와 같이 UE 고유 또는 TP 고유 정보 또는 RNTI 값인

또는

등이 될 수 있다.In addition, among the parameters for determining the initialization value as shown in Equation (3)

In the case of indicating that 1-bit information additionally included in the DCI format generates an initialization value A or a first initialization value (initialization value for generating the same reference signal sequence from each other), the value is obtained in the same manner as in the previous equation (1). When this is specified and 1-bit information additionally included in the DCI format indicates to generate an initialization value B or a second initialization value (initialization value for generating different reference signal sequences),

Replaced with this value, the UE specific or TP specific information or RNTI value as described above.

or

It can be back.

는 본 발명이 적용되는 경우

를 대체하는 파라미터를 의미하나, 동일한 의미와 용도를 가지는 한도 내에서 상기와 같은 방식의 표기에 한정되는 것이 아니라 다른 방식으로 표기할 수도 있을 것이다. (예를 들어,

가 본 발명의 내용을 포함하여서 동일하게 파라미터로 사용될 수도 있을 것이다.)here

When the present invention is applied

It means a parameter that replaces, but is not limited to the above-described notation in the same manner and within the limits having the same meaning and use, it may be indicated in other ways. (E.g,

It may also be used as a parameter, including the contents of the present invention.)

), 공통 셀 아이디(common cell ID), RNTI 정보, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등이 될 수 있으며, 그 중에서 단말이 모르고 있는 정보라면 eNodeB가 미리 RRC 시그널링 등을 이용하여 해당 초기화 값 생성정보를 UE에게 전송해 두어야 한다.Also, in method 2, the cell ID (

), Common cell ID (common cell ID), RNTI information, UE-specific information defined separately, TP-specific information defined separately, CSI-RS-related parameters, and the like, eNodeB can be used in advance if the UE does not know the information. The corresponding initialization value generation information should be transmitted to the UE using RRC signaling or the like.

Method 3 for generating selection instruction information: mixing method (instead of Table 2, the instruction information related to the changed DM-RS is configured, and additional 1 bit of information is used)

The selection instruction information generation method 3 defines changed reference signal instruction information, unlike the previously defined reference signal instruction information, as shown in Table 2, but additionally expresses 1 bit of additional information to designate the same / different initialization value. It is the method to use.

That is, as shown in Table 3 or Table 4 below, a table corresponding to antenna port, scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers), which is 3 bits of information included in the existing DCI format 2C, is , SCID defines an information table of antenna port (s) and number of layers of 3 bits that does not include, but additionally defines 1 additional bit for designating initialization value A or B separately. Therefore, in method 3, the selection indication information is a total of 4 bits of information.

In the conventional method shown in Table 2, antenna ports 7, 8 are used for MU-MIMO, and SCID = 0 and 1 are used for 7, 8, respectively, to enable MU-MIMO for a total of up to 4 layers. Did. However, in this case, orthogonality is perfectly guaranteed between antenna ports, but when the SCID is different, only quasi-orthogonal is guaranteed, not perfect orthogonality.

Therefore, it is more preferable to ensure complete orthogonality of all reference signals by classifying only the antenna port rather than classifying the layers of the MU-MIMO by SCID. Table 3 or Table 4 below of Method 3 is the antenna ports and layers in this case. It becomes the number (Antenna port (s) and number of layers) information table.

In the table shown in Table 3 or Table 4, in addition to the existing antenna ports 7, 8, two additional antenna ports may be used, for example, antenna ports 9 and 10 are added or antenna ports 11 and 13 are added. Therefore, in Method 3, Table 3 or Table 4 may be used instead of Table 2. In this case, the SCID value is included in DCI and is not specified.

[Table 3]

[Table 4]

Accordingly, if the present invention is applied based on Table 3 or Table 4, the equation for obtaining the initial value of Equation 1 may be replaced by Equation 5 or Equation 6 below. Here, since the formula for r (m), which is the entire sequence, is the same as Equation 1, the expression is omitted.

That is, when the 1-bit information additionally included in the DCI format indicates to generate the initialization value A (initialization value for generating the same reference signal sequence) (for example, the bit value is 0 (or vice versa 1)) ), The initialization value may be calculated by Equation 5 below.

[Equation 5]

Meanwhile, when 1-bit information additionally included in the DCI format indicates to generate an initialization value B (initialization value for generating different reference signal sequences) (for example, a bit value is 1 (or vice versa, 0)) , Initialization value may be calculated by Equation 6 below.

[Equation 6]

)는 DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 A(서로 동일한 참조신호 시퀀스의 생성을 위한 초기화 값)를 생성하는 것을 지시하는 경우에는 새로이 정의되는 공통 셀 아이디(common cell ID)가 될 수도 있고 기존 수학식1과 동일하게 UE가 속한 셀 또는 포인트(point)의 셀 아이디(cell ID)일 수도 있다. Compared to Equation 1, the cell ID in Equation 5 and Equation 6 (

) Indicates that the newly defined common cell ID is used when 1-bit information included in the DCI format indicates to generate an initialization value A (initialization value for generation of the same reference signal sequence). Or it may be the cell ID (cell ID) of the cell or point to which the UE belongs, as in Equation 1 above.

However, when the 1-bit information additionally included in the DCI format indicates to generate an initialization value B (initialization value for generating different reference signal sequences), the cell or point to which the UE belongs is the same as in Equation 1 above. Only the cell ID of (point) can be used.

에 대응되는 nA값의 경우에는, DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 A(서로 동일한 참조신호 시퀀스의 생성을 위한 초기화 값)를 생성하는 경우에는 특정한 디폴트 값(예를 들어 수학식 5에서 표기한 것과 같이 0, 물론 다른 특정한 값을 가질 수도 있다)을 가지며, DCI 포맷에 추가로 포함되는 1비트 정보가 초기화 값 B(서로 다른 참조신호 시퀀스의 생성을 위한 초기화 값)를 생성하는 것을 지시하는 경우에서는

값은 앞서 설명한 바와 같이 UE 고유 또는 TP 고유의 값, 예를 들면, RNTI 정보, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등이 될 수 있다.Also, Equation 1

In the case of the nA value corresponding to, when the 1-bit information additionally included in the DCI format generates the initialization value A (initialization value for generating the same reference signal sequence to each other), a specific default value (for example, an equation) As indicated in 5, 1 bit information additionally included in the DCI format has 0, of course, may have other specific values, and generates an initialization value B (initialization value for generating different reference signal sequences). In the case of instructing

As described above, UE-specific or TP-specific values may be, for example, RNTI information, UE-specific information defined separately, TP-specific information defined separately, CSI-RS-related parameters, and the like.

는 본 발명의 적용되는

를 대체하는 파라미터를 의미하나, 동일한 의미와 용도를 가지는 한도 내에서 상기와 같은 방식의 표기에 한정되는 것이 아니라 다른 방식으로 표기할 수도 있을 것이다. (예를 들어,

가 본 발명의 내용을 포함하여서 동일하게 파라미터로 사용될 수도 있을 것이다.)In equations 5 and 6,

Is applied to the present invention

Means a parameter that substitutes for, but is not limited to the above-described notation within the limits having the same meaning and use, and may be indicated in another way. (E.g,

It may also be used as a parameter, including the contents of the present invention.)

), 공통 셀 아이디(common cell ID), RNTI 정보, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등이 될 수 있으며, 그 중에서 단말이 모르고 있는 정보라면 eNodeB가 미리 RRC 시그널링 등을 이용하여 해당 초기화 값 생성정보를 UE에게 전송해 두어야 한다.Also, in Method 2, the cell ID (initial value generation information) for generating the reference signal sequence initialization value (A or B) corresponding to the initialization value selection instruction information is

), Common cell ID (common cell ID), RNTI information, UE-specific information defined separately, TP-specific information defined separately, CSI-RS-related parameters, and the like, eNodeB can be used in advance if the UE does not know the information. The corresponding initialization value generation information should be transmitted to the UE using RRC signaling or the like.

Method 4 for generating selection instruction information: an implicit method (defining instruction information related to a new 4-bit DM-RS instead of Table 2)

As shown in Table 2, the method for generating selection instruction information 4 is a method of defining new reference signal instruction information using a total of 4 bits and implicitly using the selection instruction information as shown in Table 2, using a total of 4 bits. .

That is, as shown in Table 5 or Table 6 below, as a table corresponding to antenna port, scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers) that are 3 bits of information included in the existing DCI format 2C, After adding 1 bit, a new antenna port, scrambling identifier and number of layers information table having a total of 4 bits are defined, and then selection instruction information is implicitly indicated using the information table.

More specifically, SCID = through the SCID value indicated by being included in the 4-bit antenna port, scrambling identifier, and scrambling identity and number of layers information shown in Table 5 or Table 6 below. If it is 0, it generates 'initialization value A (initialization value for generating the same reference signal sequence)', and if SCID = 1, it generates 'initialization value B (initialization value for generating different reference signal sequences)'. Conversely, if SCID = 1, 'initialization value A (initialization value for generating the same reference signal sequence)' is generated, and if SCID = 0, 'initialization value B (initialization value for generating different reference signal sequences)' is generated. You can also create

 [Table 5]

or

[Table 6]

or

According to the method 4, the equation for obtaining the initialization value of Equation 1 may be replaced by Equation 7 or Equation 8 below. Here, since the formula for r (m), which is the entire sequence, is the same as Equation 1, the expression is omitted.

[Equation 7]

[Equation 8]

That is, in the method 1, the signaling bit is the same as 3 bits compared to the case of the DCI format of the existing Rel-10, and the method 2 and the method 3 correspond to a case where an additional 1 bit is added to the 3 bits, and the method 4 is the method It is a method of modifying 2 and method 3 to give more flexibility of DM-RS orthogonal port selection.

Table 5 Table 6 includes the case of selecting the orthogonal port of the DM-RS as much as possible (a total of 8 orthogonal ports can be used for MU-MIMO). You can also increase the number of reserved rows.

Figure 4 shows the overall flow of the reference signal transmission method according to an embodiment of the present invention.

First, each reference signal transmission point (TP) in generating a reference signal to be transmitted to each UE, considering the communication environment of a specific UE, the same reference signal sequence initialization value A (or first initialization value) for all UEs or all TPs And selecting a reference signal sequence initialization value B (or a second initialization value) different from each other to generate a reference signal sequence based on the corresponding initialization value (S420).

The eNodeB and / or the transmission point (TP) generates selection indication information, which is information about the selected initialization value among the first initialization value and the second initialization value, and transmits the selected indication information to the UE in DCI format (S425). As described above, the selection indication information includes 3 bits of antenna port, scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers) included in DCI format 2C, or newly defined antenna ports of 4 bits. , Scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers) may be indicated implicitly from the information, or may be generated by additionally using an additional 1-bit explicit indication bit. will be.

For the method of generating the selection indication information, methods 1 to 4 described above in relation to Equations 2 to 8 may be used, and detailed descriptions are omitted to avoid duplication.

In addition, the transmission point maps the reference signal sequence generated in step S420 to RE (S430), generates a reference signal and transmits it to the corresponding terminal (S435).

On the other hand, the UE (UE) selects the selection information, which is information on the selected initialization value among the first initialization value and the second initialization value, and the corresponding reference signal generated and transmitted according to the selection indication information from the eNodeB and / or the transmission point It is received (S440).

), 공통 셀 아이디(common cell ID), RNTI 정보, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등이 될 수 있으나 그에 한정되는 것은 아니다.In addition, the transmission point may further include the step (S410) of transmitting the initialization value generation information necessary for generating or changing the first initialization value or the second initialization value to the corresponding terminal, and the initialization value generation information is the cell ID (

), Common cell ID, RNTI information, UE-specific information separately defined, TP-specific information separately defined, CSI-RS-related parameters, and the like, but are not limited thereto.

When the transmission point transmits the initialization value generation information to the terminal, higher layer signaling such as RRC may be used, but is not limited thereto.

The terminal may receive the initialization value generation information transmitted by the transmission point (S415).

Meanwhile, RNTI information, cell ID of a cell or a point to which a UE belongs, and CSI-RS-related information among the initialization value generation information required to generate or change the first initialization value or the second initialization value are the terminals. This may be recognized in advance, and in the case of such initialization value generation information, the transmission point will not need to be transmitted to the terminal separately. In this case, the steps S410 and S415 may be omitted.

Which of the initialization value generation information will be used may be determined according to the environment of the communication system, that is, CoMP scenario type, CoMP method, and whether MU-MIMO is supported.

The terminal receives the selection instruction information for the reference signal sequence initialization value (A or B) from the transmission point, and the terminal generates a reference signal in the manner indicated by the selection instruction information using previously received or known initialization value generation information. (S445)

Then, the channel is estimated by comparing the reference signal generated in step S445 with the reference signal received from the transmission point in step S440. (S450)

Accordingly, in a communication system supporting CoMP and / or MU-MIMO, a channel may be estimated by transmitting the same or different reference signals for each UE or each TP according to the environment in which the UE is in a situation.

5 is a flowchart of a method for transmitting a reference signal of a transmission point according to an embodiment of the present invention.

Here, the subject transmitting the reference signal may be each transmission point, and the subject transmitting the reference signal and the indication information related to generation may be a transmission point receiving the indication information from the eNodeB and / or the eNodeB. Therefore, strictly speaking, a method and an apparatus may be distinguished from an eNodeB and a transmission point, but since the eNodeB may correspond to a single transmission point, the present invention will be described by integrating the method and apparatus in the transmission point.

In generating a reference signal to be transmitted to each UE, the transmission point (TP) considers a communication environment of a specific UE, and the same reference signal sequence initialization value A (or first initialization value) for each UE or all TPs and different reference signals One sequence initialization value B (or second initialization value) is selected to generate a reference signal sequence based on the initialization value (S510).

Next, the transmission point generates selection indication information, which is information on the selected initialization value among the first initialization value and the second initialization value, and transmits the selected indication information to the terminal in a DCI format (S520).

The selection indication information in one embodiment of the present invention is the antenna port of 3 bits included in the existing DCI format 2C, scrambling identifier and layer number (Antenna port (s), scrambling identity and number of layers) information or newly defined It may be indicated implicitly from a 4-bit antenna port, scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers information, etc.), and indication information related to DM-RS as described above. It may be indicated explicitly, including a 1-bit indication bit defined separately with.

For the method of generating the selection indication information, methods 1 to 4 described above in relation to Equations 2 to 8 may be used, and detailed descriptions are omitted to avoid duplication.

Next, the transmission point maps the reference signal sequence generated in step S520 to RE (S530), generates a reference signal and transmits it to the corresponding terminal (S540).

), 공통 셀 아이디(common cell ID), RNTI 정보, 별도로 정의되는 UE 고유 정보, 별도로 정의되는 TP 고유 정보, CSI-RS 관련 파라미터 등이 될 수 있으나 그에 한정되는 것은 아니다.In addition, the transmission point may further include a step (S505) of generating and transmitting initialization value generation information necessary for generating or changing a first initialization value or a second initialization value before performing the step S510, , The initial value creation information is the cell ID (

), Common cell ID, RNTI information, UE-specific information separately defined, TP-specific information separately defined, CSI-RS-related parameters, and the like, but are not limited thereto.

When the transmission point transmits the initialization value generation information to the terminal, higher layer signaling such as RRC may be used, but is not limited thereto.

Meanwhile, RNTI information, cell ID of a cell or a point to which a UE belongs, and CSI-RS-related information among the initialization value generation information required to generate or change the first initialization value or the second initialization value are the terminals. This may be recognized in advance, and in the case of such initialization value generation information, the transmission point will not need to be transmitted to the terminal separately. In this case, step S505 may be omitted.

6 shows a flow of a channel estimation method of a terminal according to an embodiment of the present invention.

According to an embodiment of the present invention, the terminal receives selection indication information for a reference signal sequence initialization value transmitted by a transmission point such as an eNodeB (S610).

The selection indication information includes a reference signal sequence initialization value A (or a first initialization value) and a reference signal sequence initialization value B (or a second initialization) different from each other or all TPs having a sequence initialization value of a reference signal to be transmitted by a transmission point. Value), which may be transmitted in DCI format.

As described above, the selection indication information includes 3 bits of antenna port, scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers) included in DCI format 2C, or newly defined antenna ports of 4 bits. , Scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers) may be indicated implicitly from the information, or may be generated by additionally using an additional 1-bit explicit indication bit. will be. For the method of generating the selection indication information, methods 1 to 4 described above in relation to Equations 2 to 8 may be used, and detailed descriptions are omitted to avoid duplication.

In addition, the terminal receives a reference signal that the transmission point generates and transmits according to the selection instruction information (S620).

Then, the terminal confirms the initialization value generation information for generating the reference signal sequence (S630), and then generates the reference signal in the manner indicated by the selection indication information using the verified initialization value generation information (S640).

Then, the channel is estimated by comparing the reference signal generated in step S640 with the reference signal received from the transmission point in step S620. (S650)

Meanwhile, the terminal may further include a step (S605) of receiving initialization value generation information necessary for generating or changing a first initialization value or a second initialization value from a transmission point from a transmission point, such as RRC (S605). The generated information may be cell ID, common cell ID, RNTI information, UE-specific information defined separately, TP-specific information defined separately, CSI-RS-related parameters, etc., but is not limited thereto. no.

Meanwhile, among the initialization value generation information required to generate or change the first initialization value or the second initialization value, RNTI information, a cell ID of a cell or a point to which the UE belongs, or a cell ID, CSI-RS related information, etc. This may be recognized in advance, and in the case of such initialization value generation information, the transmission point will not need to be transmitted to the terminal separately. In this case, the step S605 may be omitted.

7 is an internal configuration diagram of an apparatus for generating and transmitting reference signals and information related to reference signal generation according to an embodiment of the present invention.

The apparatus for generating and transmitting reference signals and information related to reference signal generation according to the present embodiment may be implemented as an internal node or a part of an eNodeB and / or a transmission point, but is not limited thereto.

The apparatus 700 for generating and transmitting reference signals and information related to reference signal generation according to the present invention includes a selection instruction information generator 710 for generating selection instruction information for an initialization value of a reference signal sequence, and a determined method. And a reference signal generator 720 for generating a downlink reference signal, and a transmitter 730 for transmitting the selection indication information and the generated reference signal to the terminal, optionally changing the initialization value of the reference signal sequence or The initialization value generation information processing unit 740 which generates initialization value generation information for generation and transmits the generated information to the terminal may be further included.

In generating the reference signal to be transmitted to each UE, the selection indication information generating unit 710 considers the communication environment of a specific UE, and the same reference signal sequence initialization value A (or first initialization value) for each UE or all TPs and each other The selection indication information indicating one of the different reference signal sequence initialization values B (or the second initialization values) is generated.

The selection indication information is the antenna port, scrambling identifier and layer number (Antenna port (s), scrambling identity and number of layers) information included in DCI format 2C as described above with respect to Equations 2 to 8 or It may be indicated implicitly from the newly defined antenna port of 4 bits, scrambling identifier and number of layers (Antenna port (s), scrambling identity and number of layers), or may include a 1-bit indication bit separately. It may be indicated explicitly.

The generated selection indication information may be transmitted to the terminal in DCI format or the like through the transmitter 730.

The reference signal generation unit 720 performs a function of generating a downlink reference signal in a manner corresponding to the selection indication information transmitted to the terminal. At this time, it is the same as each UE or TP according to the initialization value (A or B) or Different reference signals can be generated.

In addition, the initialization value generation information processing unit 740 is a cell ID (cell ID), common cell ID (common cell ID), RNTI information, UE defined separately for the generation or change of the first initialization value or the second initialization value After generating initialization value generation information such as information, separately defined TP-specific information, and CSI-RS-related parameters, a function of transmitting to the terminal through RRC signaling may be performed through the transmitter.

8 is an internal configuration diagram of a channel estimation apparatus according to an embodiment of the present invention.

The channel estimation apparatus according to the present embodiment may be implemented inside the terminal or as part of the terminal, but is not limited thereto.

The channel estimation apparatus 800 according to an embodiment of the present invention includes a reference signal receiver 810 for receiving a reference signal from a transmission point, and a selection instruction for receiving selection instruction information that is information about an initialization value of a reference signal from a transmission point The information receiving unit 720, the initialization value generation information checking unit 830 for checking the initialization value generation information for generating or changing the initialization value used for generating the reference signal, and the received selection instruction information and the confirmed initialization value generation A reference signal generator 840 for generating a reference signal based on information and a channel estimator 850 for estimating a channel state by comparing the generated reference signal with the received reference signal may be included. In addition, the initialization value generation information receiving unit 860 received from the initialization value generation information transmission point for selectively changing or generating the initialization value of the reference signal sequence may be further included.

The reference signal receiving unit 810 receives a reference signal transmitted by a transmission point, wherein the reference signal is a reference signal generated and transmitted according to the selection instruction information according to the present invention, and the selection instruction information is transmitted by the transmission point Indicating whether the sequence initialization value of the reference signal is the same as the reference signal sequence initialization value A (or the first initialization value) and the reference signal sequence initialization value B (or the second initialization value) different from each other for all UEs or all TPs. Information.

The selection indication information is information that is explicitly or implicitly known, and is generated and transmitted by the transmission point according to the equations 2 to 8, and the selection indication information receiving unit 820 receives it.

The initialization value generation information confirming unit 830 checks initialization value generation information for generating or changing an initialization value used when generating a terminal reference signal. As the initialization value generation information, the cell or point to which the UE belongs (point) ) Cell ID, common cell ID, RNTI information, UE-specific information separately defined, TP-specific information separately defined, CSI-RS-related parameters, etc., but are not limited thereto. . Further, the initialization value generation information may be recognized by the terminal in advance, but in some cases, the initialization value generation information receiving unit 860 may be grasped by receiving from the transmission point.

The reference signal generation unit 840 performs a function of generating a reference signal in a manner corresponding to the selection indication information received using the confirmation or received initialization value generation information.

The channel estimator 850 compares the reference signal generated by the reference signal generator 840 with the reference signal received by the reference signal receiver 810 to estimate the channel state as a result.

When using one embodiment of the present invention as described above, in generating a downlink reference signal to be transmitted to each terminal in a communication system that supports CoMP and / or MU-MIMO, each terminal according to the environment in which each terminal is located Alternatively, there is an effect of selecting one of the same reference signal sequence initialization value (A) or the different reference signal sequence initialization value (B) for each transmission point to generate a reference signal so that the channel estimation of the terminal can be accurately performed. .

In addition, by dynamically instructing the type of the reference signal initialization value (A or B) to maintain or improve the orthogonality and / or pseudo orthogonality of the downlink reference signal in the communication environment of CoMP or MIMO. It has the effect.

In the above, even if all the components constituting the embodiments of the present invention are described as being combined or operated as one, the present invention is not necessarily limited to these embodiments. That is, if it is within the scope of the present invention, all of the components may be selectively combined and operated. In addition, although all of the components may be implemented as one independent hardware, a part or all of the components are selectively combined to perform a combined function of some or all of the functions in one or a plurality of hardware. It may be implemented as a computer program having a. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art of the present invention. Such a computer program is stored in a computer readable storage medium (Computer Readable Media) and read and executed by a computer, thereby realizing an embodiment of the present invention. The storage medium of the computer program may include a magnetic recording medium, an optical recording medium, a carrier wave medium, and the like.

In addition, the terms "include", "consist" or "have" as described above mean that the corresponding component can be inherent, unless specifically stated otherwise, to exclude other components. It should not be interpreted as being able to further include other components. All terms, including technical or scientific terms, have the same meaning as generally understood by a person skilled in the art to which the present invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted as being consistent with the meaning of the context of the related art, and are not to be interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (20)

As a user terminal (UE),
Radio; And
A processing element operably connected to the radio
And the processing element causes the UE to:
Receiving a first reference signal from a base station (BS);
First initialization value generation information related to a first value of scrambling code identity (SCID) (n _SCID ) information through higher layer signaling, and second initialization value related to a second value of the SCID (n _SCID ) information Generation information is received-the first initialization value generation information and the second initialization value generation information include respective cell identifier (cell ID) information, and the respective cell ID information is the respective SCID (n _SCID ). Selected based on information-;
Receive second information indicating the antenna port (s), scrambling identifier and number of layers;
Determine the selected SCID (n _SCID ) information based on the second information;
And configured to estimate a channel state based on the first reference signal and the selected SCID (n _SCID ) information. 2. The method of claim 1, to estimate the channel state, the processing element causes the UE to:
Generate a second reference signal based on the selected SCID (n _SCID ) information;
And further configured to compare the first reference signal and the second reference signal. The UE of claim 1, wherein the upper layer signaling corresponds to radio resource control (RRC) signaling. The UE of claim 1, wherein the second information is included in downlink control information (DCI). The UE according to claim 4, wherein the second information corresponds to 3 bit information. The method of claim 1, wherein the first reference signal is:
Cell specific reference signal (CRS);
Multimedia broadcast and multicast single frequency network reference signals (MBSFNRS);
UE specific reference signal or demodulation reference signal (DM-RS), positioning reference signal (PRS) according to the use of the signal; or
Channel status information reference signal (CSI-RS)
UE, which is a downlink reference signal corresponding to one of the. The UE of claim 1, wherein the respective cell identifier (cell ID) information has 9 bits. A device for estimating the channel state,
Processor
The processor includes a user terminal device (UE):
Receiving a first reference signal from a base station (BS);
Receives first initialization value generation information related to a first value of scrambling code identifier (SCID) (n _SCID ) information and second initialization value generation information related to a second value of the SCID (n _SCID ) information through higher layer signaling And-the first initialization value generation information and the second initialization value generation information include respective cell identifier (cell ID) information, and the respective cell ID information is based on the respective SCID (n _SCID ) information. Selected-;
Receive second information indicative of antenna port (s), scrambling identifier and number of layers;
Based on the second information, selection information regarding SCID (nSCID) information is determined;
And to estimate a channel condition based on the first reference signal and the selection information. 9. The method of claim 8, to estimate the channel state, the processor causes the UE to:
Generate a second reference signal based on the selected SCID (nSCID) information;
And further configured to compare the first reference signal with the second reference signal. 10. The apparatus of claim 8, wherein the higher layer signaling corresponds to radio resource control (RRC) signaling. The apparatus of claim 8, wherein the second information is included in downlink control information (DCI). 12. The apparatus of claim 11, wherein the second information corresponds to 3 bit information. 9. The method of claim 8, wherein the first reference signal is:
Cell specific reference signal (CRS);
Multimedia broadcast and multicast single frequency network reference signals (MBSFNRS);
UE specific reference signal or demodulation reference signal (DM-RS), positioning reference signal (PRS) according to the use of the signal; or
Channel status information reference signal (CSI-RS)
A downlink reference signal corresponding to one of the devices. The apparatus of claim 8, wherein the respective cell identifier (cell ID) information has 9 bits. A method of transmitting a reference signal,
At the transmitting station:
Configuring first initialization value generation information related to a first value of scrambling code identifier (SCID) (n _SCID ) information and second initialization value generation information related to a second value of the SCID (n _SCID ) information-the first 1 initialization value generation information and the second initialization value generation information include respective cell identifier (cell ID) information, and the respective cell ID information is selected based on the SCID (n _SCID ) information-;
Transmitting the first initialization value generation information and the second initialization value generation information to a user terminal (UE) through higher layer signaling;
Transmitting selection information to the UE-the selection information includes antenna port (s); Scrambling identifier; And number of layers-;
Generating a reference signal for the UE based on one of a first initialization value and a second initialization value associated with the selection information-the first initialization value is determined based on the first initialization value generation information, and the A second initialization value is determined based on the second initialization value generation information-; And
Transmitting the generated reference signal to the UE
How to include. 16. The method of claim 15, wherein the higher layer signaling corresponds to radio resource control (RRC) signaling. 16. The method of claim 15, wherein the selection information is included in downlink control information (DCI). 16. The method of claim 15, wherein the selection information corresponds to 3 bit information. 16. The method of claim 15, wherein the reference signal is:
Cell specific reference signal (CRS);
Multimedia broadcast and multicast single frequency network reference signals (MBSFNRS);
UE specific reference signal or demodulation reference signal (DM-RS), positioning reference signal (PRS) according to the use of the signal; or
Channel status information reference signal (CSI-RS)
A downlink reference signal corresponding to one of the methods. 16. The method of claim 15, wherein the respective cell identifier (cell ID) information has 9 bits.

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