KR20120015977A - Apparatus and method for transmitting muting information, and channel state acquisition apparatus and method using the same - Google Patents

Abstract

PURPOSE: An apparatus and method for transmitting muting information and an apparatus and method for acquiring a channel state using the same are provided to check a channel state by performing decoding in consideration of a muting area based on muting information. CONSTITUTION: Adjacent cell information, which includes one or more of a CSI-RS(Channel State Information Reference Signal) pattern, a CSI-RS antenna port count, a CSI-RS transfer period, and a CSI-RS transmission subframe offset information, is received from an adjacent cell(S1505). A muting area, which is a time/frequency domain of needing muting, is determined based on the adjacent cell information received(S1510). Muting information, which includes a first data field and a second data field, is generated(S1515). Generated muting information is transmitted to a terminal(S1520). Resource mapping is performed in consideration of the muting domain determined(S1525).

Description

Apparatus and Method for Transmitting Muting Information, and Channel State Acquisition Apparatus and Method using the same

An embodiment of the present invention relates to a wireless communication system, and more particularly, in a wireless communication system, when a channel state information-reference signal (CSI-RS) is allocated, In the method and apparatus for muting the entire or partial resource region of the physical space (PDSCH, Physical Downlink Shared Channel) for data transmission of the serving cell to avoid interference, It is about.

As communication systems have evolved, consumers, such as businesses and individuals, have used a wide variety of wireless terminals.

In the current mobile communication systems such as 3GPP, Long Term Evolution (LTE), LTE-A (LTE Advanced), etc., it is a high-speed large-capacity communication system that can transmit and receive various data such as video, wireless data, etc. Not only is the development of technology capable of transmitting large amounts of data comparable to wired communication networks, but also the proper error detection method to improve system performance by minimizing the reduction of information loss and increasing system transmission efficiency has become an essential element. .

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

For example, in an LTE system, which is one of mobile communication methods, a cell-specific reference signal (CRS), which is a reference signal or a reference signal, is received every subframe in order to identify channel information during downlink transmission. each subframe).

In this case, the CRS is differently allocated in time / frequency for each of four antennas according to the maximum number of antenna ports supported by downlink of the LTE system and transmitted.

In the next-generation communication technology such as LTE-A, which is currently under development, uplink can support up to 8 antennas. Accordingly, in order to grasp channel information during downlink transmission, it is limited to CRS defined only for the existing 4 antennas. For this purpose, the CSI-RS (CSI-RS) (hereinafter referred to as "CSI-RS") is newly defined to determine the channel state information for up to eight antennas.

In other words, a communication system using up to 8 × 8 multiple input multiple output antennas (MIMO) in both transmitting and receiving terminals has been discussed. An antenna port for receiving or transmitting a signal by a user equipment (UE) or Different CSI-RSs should be transmitted for each antenna layer. Although the basic definition and overhead of the current CSI-RS have been determined, specifically, the corresponding CSI-RS pattern is allocated to each antenna / base station (cell). There is no way to assign and transfer an area.

In particular, in a communication environment in which one terminal needs to receive CSI-RSs from several base stations or cells, there is a possibility that interference between CSI-RSs from other neighboring cells may occur, so consideration of this is also required.

One embodiment of the present invention is to provide an apparatus and method for allocating a channel state information reference signal (CSI-RS) to a time-frequency resource region for each antenna port for transmission or reception.

Another embodiment of the present invention is to provide a technique for muting not transmitting data in the CSI-RS allocation resource region of another cell in resource allocation of each cell (CSI-RS).

Another embodiment of the present invention is to provide a technique for generating, transmitting and receiving muting information indicating a data muting area when transmitting a CSI-RS.

Another embodiment of the present invention considers one or more of the CSI-RS pattern, the number of CSI-RS antenna ports, the CSI-RS transmission duty cycle, and the CSI-RS transmission subframe offset information of a neighbor cell, The present invention provides a technique for generating, transmitting and receiving muting information indicating a muting area in which data is not allocated when a resource is allocated.

Another embodiment of the present invention is to provide a technique for transmitting and receiving muting information, and resource allocation of the CSI-RS so as not to send data to the muting area based on the muting information.

Another embodiment of the present invention is to provide a technique for estimating or obtaining a channel state by receiving muting information and then decoding it in consideration of the muting region based thereon.

According to an embodiment of the present invention, in a multi-cell environment, a specific cell transmits muting information considering the CSI-RS interference of a neighbor cell, wherein the specific cell includes a CSI-RS pattern and a CSI-RS antenna from the neighbor cell. Receiving CSI-RS information of a neighbor cell including at least one of port number, CSI-RS transmission duty cycle, and CSI-RS transmission subframe offset information; and receiving CSI-RS information of the neighbor cell. Determining a muting region, which is a time / frequency region requiring muting by overlapping with the CSI-RS of the neighboring cell, based on a first data field indicating a muting period and a muting offset of a muting subframe included in the muting region; Generating muting information including a second data field representing at least one of a muting pattern group in the muting subframe and a specific muting pattern in the muting pattern group; It provides a muting information transmission method comprising the step of transmitting the muting information to the terminal.

In addition, an embodiment of the present invention is a method for acquiring a channel state of each cell after a receiver receives a CSI-RS from two or more cells, wherein the receiver is a muting subframe from a serving cell among two or more cells. Receiving muting information including a first data field indicating a muting period and a muting offset of the second data field, and a second data field indicating at least one of a muting pattern group and a specific muting pattern in the muting subframe, and CSI of a serving cell; Receiving a CSI-RS of a neighbor cell transmitted from a resource region of a neighboring cell corresponding to a partial region muted by the muting information in a resource space for data transmission of an RS and a serving cell; and using the muting information Identifying a muting area in a resource space for data transmission of the serving cell and identifying a CSI-RS transmission area of a neighboring cell corresponding thereto; and Consider the group muting area to provide the obtained channel state comprises: obtaining channel state by decoding the CSI-RS of the serving cell and neighboring cells.

Another embodiment of the present invention, one of the CSI-RS pattern, the number of CSI-RS antenna ports, the CSI-RS Transmission Duty Cycle, CSI-RS transmission subframe offset information from one or more adjacent cells in a multi-cell environment The neighbor cell information receiver for receiving CSI-RS information of the neighbor cell including the above, and overlaps with the CSI-RS of the neighbor cell in the resource space for data transmission of the serving cell based on the CSI-RS information of the neighbor cell. A muting region determiner configured to determine a muting region, which is a time / frequency region requiring muting, a first data field indicating the muting region, a muting period and a muting offset of the muting subframe, and a muting in the muting subframe Muting information generator for generating muting information including a second data field representing at least one of a pattern group and a specific muting pattern in the muting pattern group and the generated muting Provided is a CSI-RS muting information transmitting apparatus including a muting information transmitting unit for transmitting information to a UE.

In another embodiment of the present invention, a first data field indicating a muting period and a muting offset of a muting subframe from a serving cell among two or more cells, a first muting pattern group and at least one of a specific muting pattern in the muting subframe. A muting information receiver for receiving muting information including a data field, and a resource region of a neighboring cell corresponding to a partial region muted by the muting information in a CSI-RS of a serving cell and a resource space for data transmission of a serving cell A CSI-RS receiver for receiving a CSI-RS signal of a neighboring cell transmitted from the CSI-RS receiver, and confirming a muting area in a resource space for data transmission of the serving cell using the muting information, and corresponding CSI-RS of the neighboring cell; Muting area checking unit for identifying an RS transmission resource region and the CSI-RS signal of the serving cell and the neighboring cell in consideration of the muting region Provided is a channel state obtaining apparatus including a channel state obtaining unit for decoding and obtaining a channel state.

1 is a diagram schematically illustrating a wireless communication system to which an embodiment of the present invention is applied.
2 to 13 illustrate representative examples of CSI-RS mapping in one subframe, and FIGS. 2 to 5 generally apply to both FS1 (FDD) and FS2 (TDD), and are normal CPs. 6 to 9 are generally applied to both FS1 (FDD) and FS2 (TDD), and are extended CP, and FIGS. 10 to 13 are additional options for FS2 (TDD). As an example of a CSI-RS pattern, FIGS. 10 and 11 show normal CPs, and FIGS. 12 and 13 show extended CPs.
14 illustrates a multi-cell environment to which the present embodiment is applied.
15 shows a flow of a CSI-RS muting information transmission method according to the present embodiment,
16 is a flowchart of a detailed configuration of generating muting information in the present embodiment;
17 is a flowchart illustrating a method of obtaining channel information in a terminal using muting information according to the present embodiment;
18 is a configuration diagram of a CSI-RS muting information transmitting apparatus according to the present embodiment,
19 shows an example of a data format of muting information according to the present embodiment,
20 is a diagram illustrating a frame and resource space configuration indicating a state in which a CSI-RS of an actual serving cell is muted by the muting information of FIG. 19.
21 is a configuration diagram of a channel state obtaining apparatus using muting information according to the present embodiment.

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

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

1 illustrates a wireless communication system to which embodiments of the present invention are applied.

Wireless communication systems are widely deployed to provide various communication services such as voice and packet data.

Referring to FIG. 1, a wireless communication system includes a user equipment (UE) 10 and a base station 20 (BS). The terminal 10 and the base station 20 are applied with the muting information generation technique and the channel state acquisition technique using the same as the embodiment to be described below, which will be described in detail with reference to FIG.

Terminal 10 in the present specification is a generic concept that means a user terminal in wireless communication, WCDMA, UE (User Equipment) in LTE, HSPA, etc., as well as MS (Mobile Station), UT (User Terminal) in GSM ), SS (Subscriber Station), wireless device (wireless device), etc. should be interpreted as including the concept.

A base station 20 or a cell generally refers to a fixed station communicating with the terminal 10 and includes a Node-B, an evolved Node-B, and a Base Transceiver. May be called other terms such as System, Access Point, Relay Node

That is, in the present specification, the base station 20 or the cell should be interpreted in a comprehensive sense indicating some areas covered by the base station controller (BSC) in the CDMA, the NodeB of the WCDMA, and the like. It is meant to cover various coverage areas such as microcell, picocell, femtocell and relay node communication range.

In the present specification, the terminal 10 and the base station 20 are two transmitting and receiving entities used to implement the technology or the technical idea described in the present specification and are used in a comprehensive sense and are not limited by the terms or words specifically referred to.

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA Can be used.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.

One embodiment of the present invention is resource allocation in the fields of asynchronous wireless communication evolving into Long Term Evolution (LTE) and LTE-advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving into CDMA, CDMA-2000 and UMB. Can be applied to The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

A wireless communication system to which an embodiment of the present invention is applied may support uplink and / or downlink HARQ, and may use a channel quality indicator (CQI) for link adaptation. In addition, multiple access schemes for downlink and uplink transmission may be different from each other. For example, downlink uses Orthogonal Frequency Division Multiple Access (OFDMA), and uplink uses Single Carrier-Frequency Division Multiple Access (SC-FDMA). ) Is the same as can be used.

The layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) model, which are well known in communication systems. The physical layer may be divided into a second layer (L2) and a third layer (L3), and the physical layer belonging to the first layer provides an information transfer service using a physical channel.

Meanwhile, in an example of a wireless communication system to which an embodiment of the present invention is applied, one radio or radio frame includes 10 subframes and one subframe includes two slots. ) May be included.

The basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed on a subframe basis. One slot may include a plurality of OFDM symbols in the time domain and at least one subcarrier in the frequency domain, and one slot may include 7 or 6 OFDM symbols.

For example, if a subframe consists of two time slots, each time slot may include seven symbols in the time domain and twelve subcarriers or subcarriers in the frequency domain, such that time is defined as one slot. The frequency domain may be referred to as a resource block or a resource block (RB), but is not limited thereto.

Referring to the general subframe and time slot structure of the transmission data that can be applied to an embodiment of the present invention.

In 3GPP LTE and the like, the transmission time of a frame is divided into TTIs (transmission time intervals) of 1.0 ms duration. The terms "TTI" and "sub-frame" may be used in the same sense, and the frame is 10 ms long and includes 10 TTIs.

As described above, the TTI is a basic transmission unit, where one TTI includes two time slots of equal length, each time slot having a duration of 0.5 ms. The time-slot includes seven long blocks (LB) for the symbol. LBs are separated by cyclic prefixes (CP). Collectively, one TTI or subframe may include 14 LB symbols, but the present specification is not limited to such a frame, subframe or time-slot structure.

Each TTI or subframe is divided into 14 symbols (axis) in the time domain. Each symbol (axis) may carry one symbol.

In addition, the overall system bandwidth of 20 MHz is divided or divided into subcarriers of different frequencies. In the example shown, it consists of 12 consecutive subcarriers within one TTI. Thus, an area consisting of 14 symbols in the time domain and 12 subcarriers in the frequency domain is called a resource block or resource block (RB). Can be called

For example, a bandwidth of 10 MHz within 1 TTI may include 50 RBs in the frequency domain.

Each of the lattice spaces constituting the resource block RB may be referred to as a resource element (hereinafter, referred to as a “RE”). A total of 14 × 12 = 168 pieces of subframes or resource blocks having the above structure are referred to. RE may be present.

Meanwhile, in the LTE communication system, three reference signals (Reference Signal RS) are defined in downlink, a cell-specific reference signal (CRS), and an MBSFN reference signal (Multicast / Broadcast over Single Frequency Network). Reference Signal (MBSFN-RS) and UE-specific Reference Signal (UE-specific Reference Signal).

Among these, CRS is a reference signal for unicast transmission, not MBSFN transmission, and should be included in all downlink subframes in a cell that does not support MBSFN transmission. In addition, it must be transmitted on one or multiple of antenna ports 0-3.

In addition, one reference signal is transmitted for each downlink antenna port, and an RE used for CRS transmission of one of the antenna ports in the slot cannot be used for another antenna port in the same slot.

When CRSs are mapped to REs of different time-frequency domains for each of four antenna ports, REs to which CRSs for each antenna port are allocated have a period of 6 for subcarriers, which are expressed as follows.

On the other hand, as described above, in some next-generation communication technology, up to eight antennas are supported in the downlink, therefore, in order to grasp channel information during downlink transmission, there is a limit to the CRS defined only for the existing four antennas. To this end, a reference signal called a channel state information reference signal (CSI-RS) may be newly defined to identify channel state information of up to eight antennas.

The CSI-RS, which is currently discussed in LTE-A, has 12 subs corresponding to one resource block (RB) on a frequency axis for each cell in a duty cycle on a time axis for each cell. In an area of a subcarrier, one resource element (RE) is allocated for each antenna port.

That is, up to eight REs are allocated and transmitted for a total of eight antenna ports. At this time, the predetermined period corresponds to a multiple of 5ms of time consisting of five subframes (that is, 5ms or 10ms may be the predetermined period).

If the duty cycle is 5ms, the CSI-RS is transmitted in a total of two subframes out of 10 subframes in one radio frame corresponding to 10ms. Therefore, if only the CSI-RS pattern for one subframe is defined, the other subframe needs to be allocated with a certain cycle.

In this specification, a duty cycle for the transmission of the CSI-RS is defined as a CSI-RS transmission duty cycle.

Meanwhile, a communication system using up to 8 × 8 multiple input multiple output antennas (MIMO) has been discussed in both transmitting and receiving terminals, and since a different CSI-RS must be transmitted for each antenna port or antenna layer, a transmitter is used. Needs to allocate CSI-RS for a total of eight antenna ports to be distinguished in the time-frequency domain, and in particular, it is necessary to allocate CSI-RS to distinguish between cells in a multi-cell environment.

In the present specification, the antenna layer refers to a data layer that can be logically simultaneously transmitted to multiple antenna ports in a base station or a mobile communication terminal. However, data of each antenna layer may be the same or different. Therefore, the number of antenna layers may be equal to or smaller than the number of antenna ports. On the other hand, the antenna port refers to an antenna physically configured in the base station or the mobile communication terminal.

Hereinafter, although described with reference to the antenna port, it may be applied to the antenna layer unit.

At this time, although the overhead of each antenna port for one subframe is defined as the basic definition of the current CSI-RS and the above description, specifically CSI for each antenna / base station (cell) -RS allocation and transmission method is not determined.

2 to 13 illustrate a representative example of CSI-RS mapping to one subframe, and includes a structure of a subframe (hereinafter referred to as FS) and a cyclic shift (CP). It illustrates a CSI-RS pattern that can be defined according to the normal or extended ('), and the number of antenna ports (one of two, four, eight).

First, FIGS. 2 to 5 are applied to both FS1 (Frame Structure 1, FDD) and FS2 (Frame Structure 2, TDD (except DwPTS of Special Subframe)) as basic (mandatory), and are normal CPs. The CSI-RS pattern in the case is shown.

As shown in FIG. 2, for one subframe, in the case of a normal subframe, a cell-specific reference signal (CRS) and a control region (CRS), which are conventionally used among a total of 14 symbols, are used. In addition, the CSI-RS may be allocated to the resource so as not to overlap with the Demodulation Reference Signal (DM-RS) Rel-9 / 10 region location, and the unshaded RE in FIG. 2 may allocate the CSI-RS. It is an area that can be.

3 to 5 illustrate all possible CSI-RS patterns according to the number of antenna ports in the resource region as shown in FIG. 2, and each CSI-RS pattern is divided into alphabet subscripts.

As shown in FIG. 3, when eight antenna ports (antenna port numbers 0 to 7) may have a total of five CSI-RS patterns up to a patterns to e patterns.

In FIG. 3 and below, numbers are numbers of respective antenna ports or antenna layers, and alphabet subscripts are identifiers indicating CSI-RS patterns or muting patterns.

Meanwhile, the CSI-RS patterns in the case of two or four CSI-RS antenna ports instead of eight have a nested structure when the number of CSI-RS antenna ports is eight.

That is, the pattern when the number of CSI-RS antenna ports is four is composed of patterns divided within each specific pattern when the number of CSI-RS antenna ports is eight, so the total number of patterns is CSI-RS This is doubled when the number of antenna ports is eight. The pattern when the number of CSI-RS antenna ports is two is also composed of the divided patterns within each specific pattern when the number of CSI-RS antenna ports is four, so the total number of patterns is the number of CSI-RS antenna ports. It is twice as many as four.

For example, as shown in FIGS. 3 to 5, five CSI-RS patterns that are basically applied to the normal CP case in one subframe are five when the number of CSI-RS antenna ports is eight (see FIG. 3. a to e), and 10 times that of twice the number of CSI-RS antenna ports (a to j of FIG. 4) when the number of CSI-RS antenna ports is 4, and 20 kinds to which the number of CSI-RS antenna ports is 2 (a to t of FIG. 5). )

6 to 9 are identically applied to both FS1 (Frame Structure 1, FDD) and FS2 (Frame Structure 2, TDD (except DwPTS of a special subframe)), and are essentially the same. ) Shows a CSI-RS pattern in the case of CP.

As shown in FIG. 6, in the case of an extended CP, a cell-specific reference signal (CRS), a control region, and a DM-RS (Demodulation) used previously among a total of 12 symbols used for downlink Reference Signal) In consideration of the location of the Rel-9 / 10 region, the CSI-RS may be allocated so that the CSI-RS is not overlapped with each other. In FIG. 7, the unshaded RE may allocate the CSI-RS.

7 to 9 illustrate all possible CSI-RS patterns according to the number of antenna ports in the resource region as shown in FIG. 6, and each CSI-RS pattern is divided into alphabet subscripts.

As shown in FIG. 7, when eight antenna ports are provided (antenna port numbers 0 to 7), the antenna ports may have a total of four CSI-RS patterns up to a patterns to d patterns.

In addition, when there are two and four antenna ports, the same principle as in FIGS. 3 to 5 may be applied.

That is, as shown in FIGS. 7 to 9, four CSI-RS patterns applied to the extended CP case in one subframe are four when the number of CSI-RS antenna ports is eight (a to FIG. 7). d), which is twice that of the number of four CSI-RS antenna ports (eight a to h in FIG. 4), and sixteen (a to p of FIG. 5) when the number of CSI-RS antenna ports is two; do.

10 to 13 illustrate examples of CSI-RS patterns applied as additional options in case of FS2 (Frame Structure 2, TDD (except DwPTS of Special Subframe)). This is the case of normal CP, and FIGS. 12 and 13 are cases of extended CP.

FIG. 10 illustrates a resource region capable of allocating a CSI-RS in case of an additional option of FS2. In the case of a normal subframe, FIG. 10 is a cell-specific CRS (cell-specific) used in the existing 14 symbols. Reference signals, control regions, DM-RS (Demodulation Reference Signal) Rel-9 / 10 areas, and DM-RS (UE-sepcific RS) areas of Rel-8 are considered so as not to overlap them. The CSI-RS may be allocated to resources, and an unshaded RE is an area in which the CSI-RS may be allocated in FIG. 10.

FIG. 11 illustrates all CSI-RS patterns that can be used when the number of antenna ports is 8 in the resource region as shown in FIG. 10 and may have a total of three CSI-RS patterns, ranging from a to c patterns.

In addition, although not shown, two and four antenna ports, according to the same principle as described above, when the number of CSI-RS antenna ports is four, six times that is twice, when the number of CSI-RS antenna ports is two It may have 12 CSI-RS patterns.

FIG. 12 illustrates a resource area capable of allocating CSI-RS in case of an additional option of FS2. In case of normal subframe by extended CP, FIG. (CSI-RS) can be allocated to the CSI-RS so as not to overlap with the cell-specific reference signal, control region, DM-RS (Demodulation Reference Signal) Rel-9 / 10 region location. In 12, an unshaded RE is an area where CSI-RS can be allocated.

FIG. 13 illustrates all possible CSI-RS patterns when the number of antenna ports is 8 in the resource region as shown in FIG. 12 and may have a total of seven CSI-RS patterns ranging from a to g patterns. . In addition, although not shown, two and four antenna ports, according to the same principle as described above, when the number of four CSI-RS antenna ports is four times 14, and the number of two CSI-RS antenna ports two There can be a total of 28 CSI-RS patterns.

For convenience of description, in the present specification, whether essential or optional, normal or extended cyclic shift (hereinafter referred to as 'CP'), and the number of antenna ports (2, 4, 8) A set of a plurality of CSI-RS patterns that can be defined according to one) is defined as a CSI-RS Pattern Group or Muting Pattern Group, and is one that is actually adopted within the group. The specific CSI-RS pattern of is defined as a CSI-RS pattern or a muting pattern.

However, it is not limited to these terms, and other expressions or terms may be used as long as they have the same or equivalent concepts.

For example, the case is applied to a normal subframe basically (required), and the pattern a to e in the case of eight CSI-RS antenna ports (antenna port numbers 0 to 7) (that is, in case of FIG. 3). Each of the five CSI-RS patterns up to the pattern may be a CSI-RS pattern group or a muting pattern group, and the number of each CSI-RS antenna port is According to two, four, or eight, one pattern specified for actual CSI-RS allocation or muting may be defined as a CSI-RS pattern or a muting pattern.

 FIG. 14 illustrates a multi-cell environment, such as a Cooperative MultiPoint Tx / Rx System (hereinafter referred to as CoMP).

The multi-cell environment to which the present invention may be applied includes, but is not limited to, CoMP, and it should be understood that a single terminal includes all cases in which a CSI-RS should be received from two or more cells or base stations.

In a CoMP wireless communication system, which is one of a multi-cell environment, a UE receives information simultaneously from one or more base stations or cells, and a neighboring cell as well as a serving cell in which a corresponding user is currently transmitting and receiving. In a communication system that also needs to transmit and receive a reference signal with a neighbor cell, since the CSI-RS of the neighbor cell has a weaker reception power than the serving cell, the serving cell and the neighbor cell simultaneously transmit the CSI-RS on the same time / frequency resource. In the case where the serving cell transmits data and the neighbor cell transmits CSI-RS, it is difficult for the user to properly detect the CSI-RS from the neighbor cell.

For example, in FIG. 14, three cells, Cell A, Cell B, and Cell C, form a CoMP set, and a specific UE in Cell A, which is a serving cell, is connected with Cell B as well as CSI-RS from Cell A. The CSI-RS from Cell C is also received to measure channel state information. At this time, each cell has one of the patterns defined in FIGS. 2 to 13 as a CSI-RS pattern.

For example, if each cell configures eight CSI-RS antenna ports in the general CSI-RS pattern of the normal CP, each cell transmits the CSI-RS in one of five patterns as shown in FIG. Done. That is, Cell A is the first of five patterns, Cell B is the second of five patterns, and Cell C is the fourth of five patterns. Information about this pattern may be determined implicitly based on Cell ID, and may be determined explicitly by scheduling and signaling of an upper end for each base station.

Here, from the standpoint of Cell A, the serving cell, Cell A transmits CSI-RS in the region corresponding to the first pattern, which is the CSI-RS pattern for Cell A, out of five patterns, and CSI-RS for other cells. Data is transmitted for the second, third, fourth, and fifth patterns, which are patterns. From the perspective of the UE of Cell A, the UE knows that the CSI-RS for Cell A is transmitted in the region corresponding to the first pattern of information received from Cell A, which is the base station, and decodes the other 2, 3, 4, When the data corresponding to the fifth pattern is transmitted, the data is decoded.

However, in a multi-cell environment such as CoMP, the resource region corresponding to the second pattern receives not only data but also CSI-RS from Cell B. Even though CSI-RS is transmitted at higher transmission power than Cell A, Cell A is closer to UE. CSI-RS information from Cell B, which is farther away, may be subject to severe interference due to data information coming from it. Therefore, in order for the UE in Cell A to properly receive CSI-RS information from Cell B without interference, Cell A transmits at zero power without transmitting data for the resource region where Cell B transmits CSI-RS. (muting) can be performed.

In this case, the UE in Cell A does not receive data from Cell A but the information muted at zero power for the resource region where Cell B transmits CSI-RS. It knows the RS is coming and decodes it.

That is, when a CSI-RS pattern is configured for each cell in consideration of a multi-cell environment such as CoMP, CSI according to the CSI-RS pattern in neighboring cells forming a CoMP set to reduce the influence of interference with neighboring cells. For the part where -RS is to be configured, it is possible to perform muting that transmits at zero power without sending data.

As seen from the perspective of Cell A, the serving cell, as shown in FIG. 14, previously known information of Cell A to the UE in Cell A includes the CSI-RS pattern of the corresponding Cell A, the number of CSI-RS antenna ports, and the CSI-RS transmission period ( transmission duty cycle) and a transmission offset.

However, the UE in Cell A, which is the serving cell, does not know about the information related to the CSI-RS of neighbor cells. In this situation, when muting is performed in order to reduce the influence of interference with neighbor cells in a multi-cell environment, the UE in Cell A, which is a serving cell, may select Cell A for a resource region including a CSI-RS pattern in the neighbor cell. This can cause problems when decoding because it doesn't know whether it's transmitting data or muting at zero power.

In order to solve this problem, in the present embodiment, a technique for transmitting information on whether or not to mute the CSI-RS resource region in which the CSI-RS pattern of a neighboring cell capable of each cell is configured, that is, a technique for transmitting the muting information to the UE Apply.

To this end, in the simplest method, muting is performed on all parts of the CSI-RS pattern of neighboring cells, which are possible through 1-bit signaling (may be higher level signaling through RRC or PDCCH signaling). It tells you whether or not to send the data without muting.

That is, for example, if each cell configures eight CSI-RS antenna ports in the general CSI-RS pattern of the normal CP, each cell will be configured in one of the five patterns shown in FIG. In case of Cell A, Cell A mutes all of the UEs through 1 bit signaling for the region where CSI-RS for all remaining cells will be transmitted except for the region where CSI-RS for Cell A will be transmitted. It tells you whether or not to send the data without muting.

However, when muting all together, there are many areas where data is not sent in order to reduce interference with neighboring cells in a multi-cell environment, which is a waste of resources. When all data is transmitted without muting, interference problems with neighboring cells exist. Therefore, it is efficient to mute only the necessary partial region rather than muting all possible CSI-RS patterns, and the base station (Serving Cell) Needs to signal to the UE.

That is, the base station signals each terminal (UE) of which part to perform muting for transmitting zero power without transmitting data among the parts to be configured in the CSI-RS in the neighbor cell. In this case, the muting area to be signaled may be all or part of a part of the CSI-RS of all possible neighboring cells, CSI-RS pattern of neighboring cells constituting a CoMP set, and CSI of each neighboring cell. RS is configured in consideration of the number of antenna ports, a muting period (period or cycle), and an offset in time / frequency.

Specifically, in the muting information transmission method according to the present embodiment, among the CSI-RS pattern, the number of CSI-RS antenna ports, the CSI-RS transmission duty cycle, and the CSI-RS transmission subframe offset information from adjacent cells. Receiving a neighboring cell information including one or more, determining a muting region that is a time / frequency region that needs to be muted by overlapping the CSI-RS of the neighboring cell based on the neighboring cell information; Generating muting information including a first data field, the first data field indicating a muting period and a muting offset of the muting subframe, and a second data field indicating at least one of a muting pattern group and a specific muting pattern in the muting subframe; The method may include transmitting the generated muting information to the terminal.

Generating the muting information may further include a first step of determining a muting duty cycle and a muting offset and generating a first data field indicating the muting pattern cycle, a muting pattern group and a specific muting pattern in one muting subframe. And a second step of generating a second data field representing one or more of the fields.

The first step may be determined according to a relationship between the position of the muting subframe requiring muting and the CSI-RS transmission period and the CSI-RS transmission offset of the specific cell or the neighboring cell. It demonstrates in detail.

Accordingly, the muting information according to the present embodiment may have a separate value for each adjacent cell or have a single unified value, a first data field indicating a muting duty cycle and a muting offset, and one muting. It may include a second data field indicating at least one of a muting pattern group and a specific muting pattern in the subframe.

15 is a flowchart illustrating a method of transmitting CSI-RS muting information according to the present embodiment.

The CSI-RS muting information transmission method according to the present embodiment is performed by a serving cell or a serving base station currently providing a service to a terminal in a multi-cell environment, but is not limited thereto.

In the CSI-RS muting information transmission method according to the present embodiment, one of the CSI-RS pattern, the number of CSI-RS antenna ports, the CSI-RS transmission duty cycle, and the CSI-RS transmission subframe offset information from adjacent cells. Receiving neighboring cell information including the above (S1505) and determining a muting region that is a time / frequency region that requires muting by overlapping with the CSI-RS of the neighboring cell based on the received neighbor cell information (S1510). ), A first data field indicating the muting region and a muting duty cycle and a muting offset of the muting subframe, a muting pattern group and one or more muting patterns in one muting subframe. And generating the muting information including the two data fields (S1515) and transmitting the generated muting information to the terminal (S1520).

In addition, the CSI-RS transmission method according to the present embodiment considers the determined muting area when resource element mapping is performed on a physical downlink resource channel (PDSCH) for data transmission, and transmits data to the muting area. The method may further include performing a resource mapping including a muting process of transmitting zero power without transmitting and transmitting the resource mapping to the terminal (S1525). The step S1525 may be configured after the step S1520 for transmitting the muting information to the terminal, or may be configured after the step S1510 for determining the muting area or after step S1515 for generating the muting information.

In step S1505, the CSI-RS pattern, the number of CSI-RS antenna ports, and CSI-RS in one subframe configured in each neighboring base station cell from the neighboring base station cell to which the corresponding serving cell is the muting target. Adjacent cell information including information on one or more of a transmission subframe offset and a CSI-RS transmission duty cycle is received. In this case, the neighboring base station (cell) to be muted may be a neighboring base station (cell) having all other CSI-RS patterns, and as shown in FIG. 14, a CoMP set excluding a serving cell (Cell A in FIG. 14). Some neighboring base stations (Cell B and Cell C in FIG. 14) may be formed, or one or more neighboring base stations (Cells) to be subjected to other muting.

In step S1505, information is transmitted between the base station cell and the base station cell, and information transmission through the X2 interface may be an example, but is not limited thereto.

In the muting area, when a serving cell allocates a physical downlink resource channel (PDSCH) for data transmission, interference may occur in an area where a CSI-RS of an adjacent cell is allocated, so that zero power is transmitted without transmitting data. It means an area to be transmitted to, and the muting information means information used to specify the area.

16 is a flowchart of a detailed configuration of generating muting information in the present embodiment.

The muting information generation step S1515 of FIG. 15 includes a first step S1605 of determining a muting duty cycle and a muting offset and generating a first data field indicating the muting duty cycle, and muting in one muting subframe. And a second step S1610 of generating a second data field representing at least one of the pattern group and the specific muting pattern.

The base station corresponding to the serving cell configures muting information indicating a muting area for transmitting zero power without transmitting data in two stages, and the first stage of the two stages may be performed for the first time, but the second stage It may be configured after the last step, the information configured through the first step and the second step is signaled to the UE (UE), the corresponding cell based on the muting information (muting duty cycle) In each subframe corresponding to the muting offset, muting is performed at zero power without transmitting data for the muting pattern from each adjacent cell.

In this case, the muting-related information to be transmitted or signaled to the terminal may be transmitted through higher level signaling such as RRC or may be transmitted dynamically through the PDCCH.

The terminal in the serving cell decodes in consideration of the muting region (ie, the muted portion transmitted with zero power without transmitting data) found through the signaling muting information. If the UE does not know whether data is coming into the PDSCH region, or if muting is transmitted with zero power without data (in this time / frequency resource region, whether the CSI-RS from the adjacent cell is transmitted without data). If not, errors or quality deterioration may occur during decoding, but this problem does not occur when decoding in consideration of the above-described muting information.

Hereinafter, a detailed configuration of the first and second steps constituting the muting information, that is, the process of configuring the muting information, the type of information and the number of bits, will be described in detail.

● First step

Hereinafter, each case of the first step of determining a muting duty cycle and a muting offset and generating a first data field indicating the muting duty cycle will be described.

The first step is to specify the subframe to be muted in consideration of the CSI-RS related information of each corresponding neighboring cell to be muted, and the muting duty cycle and muting offset are determined. The information is configured through the base station, and the base station performs muting in a subframe represented by a corresponding muting offset at every muting duty cycle.

This information may be transmitted as the same for each corresponding neighboring cell that is the subject of all muting (in this case, only one is transmitted because the muting information is the same for the neighboring cells that are the subject of all muting), and for each muting target A plurality of neighbor cells may be transmitted. (In this case, since the muting information may be different with respect to neighbor cells which are all the muting targets, the number of neighboring cells that are the muting targets may be transmitted.)

This first step may be further divided into five cases according to how the muting period and the muting offset are related to the CSI-RS transmission period and the CSI-RS transmission offset of the serving cell. To 5).

That is, the first step is a CSI-RS transmission period and a CSI-RS of a serving cell or a neighboring cell in which a subframe (that is, a muting subframe) requiring muting among the CSI-RSs of the serving cell is considered in consideration of interference with the neighboring cell. Depending on the relationship with the transmission offset can be differently implemented differently.

In the following, the terms' muting 'and' Muting 'are used interchangeably, and the terms'offset' and 'offset', 'serving cell' and 'serving cell', 'cycle' and 'duty cycle', 'bit' and ' The terms 'bit', 'pattern group' and 'pattern group', 'antenna port' and 'antenna port', 'data' and 'data' are used interchangeably.

1) Muting cycle ( duty cycle ) and Muting offset is Serving CSI-RS transmission period of the Cell (BS) (duty cycle ) and the same as the CSI - RS transmission offset (the duty cycle and the muting offset are the same for all neighboring cells targeted for muting. The information configured below is applied to all neighboring cells targeted for muting. Is sent to the same one)

In this case, the number of information bits constituting the first data field may be 0 bits.

In this case, the serving cell (base station) determines that the subframe transmitting the CSI-RS is a subframe to be muted.

For example, if the CSI-RS transmission duty cycle of the Serving Cell is 10ms and the offset is 3, the CSI-RS is transmitted in the fourth subframe (subframe number 3), and this fourth subframe is the target of muting. Since this becomes a subframe, no additional information is needed to designate the subframe in which the CSI-RS of the neighbor cell is transmitted.

2) Muting offset is Serving CSI of the Cell (base station) - the same as the RS transmission offset and, Muting period (duty cycle ) is Serving Cell (BS) of the CSI - if a multiple of (duty cycle) RS transmission period (Muting cycle (and duty cycle), and Muting offset is equal with respect to all adjacent cells of interest into a Muting, information consisting of the following is in Muting The default is to transmit the same one for all neighboring cells, but for more accurate muting, the muting offset is the same for all neighboring cells targeted for muting, but the duty cycle is the same for each neighboring cell. It may be different from each other, and the information configured below may be configured and transmitted separately for each corresponding neighboring cell targeted for all muting.)

In this case, it can be divided into three detailed configurations, which will be described by dividing them into methods 2-1, 2-2, and 2-3.

2-1) Method 2-1

Instead of mutating all CSI-RS configuration subframes of the neighboring cells, only some of the CSI-RS configuration subframes of the neighboring cells are mutated in order to reduce an area where data cannot be transmitted due to the mutation.

bit가 필요할 수도 있지만,

bit는 전송되지 않을 수도 있다. 여기서, M은 자연수이되, 2^M 은 CSI-RS 전송 주기(duty cycle)에 대한 뮤팅 주기 (duty cycle)의 최대 배수 값보다 같거나 크게 되도록 M이 결정될 수 있다. At this time, the number of information bits constituting the first data field is 2 bits, 4 bits, 8 bits,... , 2 ^M bit (M is a natural number). Also in addition

bit may be required,

The bit may not be transmitted. Here, M may be a natural number, and ^M may be determined to be equal to or greater than a maximum multiple of a muting cycle for a CSI-RS transmission cycle.

bit가 필요할 수 있다.For example, when the maximum multiple value is 16, M = 4. In this case, the first data field may consist of one of 2, 4, 8, and 16 bits, and indicates the number of configuration bits. To further

bit may be required.

Here, when M = 4, a bitmap may be 0 or 1 for each bit of information bits consisting of 2 bits, 4 bits, 8 bits, or 16 bits, and each bit is one CSI of the serving cell. -RS corresponds to the duty cycle.

That is, for the subframe corresponding to the CSI-RS transmission offset in each CSI-RS transmission cycle, if the bit value is 0, muting and if 1, data may be transmitted (of course, 0 days). Data transmission when 1, Muting when 1).

bit로 따로 시그널링을 해줄 수도 있게 된다. 만약 M=4일 경우, 따로 시그널링 해 주거나 추가로 포함되는 비트 수는 2bit가 되며, 그 비트 값이 ‘00’이면 상기 구성되는 정보 비트 수는 2bit, ‘01’이면 4bit, ‘10’이면 8bit, ‘11’이면 16bit가 된다.Also, how many bits of information bits constituted the first data field are?

Signaling can be done separately by bit. If M = 4, the number of bits separately signaled or additionally included is 2 bits. If the bit value is '00', the configured number of information bits is 2 bits, 4 bits if '01', and 8 bits if '10'. '11' means 16 bits.

In this case, only when the bit value is 0 for each bit value of the information bit constituting the first data field, it corresponds to the CSI-RS transmission offset in the CSI-RS transmission cycle of the serving cell. The subframe is determined to be a subframe to be muted.

For example, if the CSI-RS transmission duty cycle of the Serving Cell is 10 ms and the offset is 3, the CSI-RS is transmitted in a fourth subframe (subframe number 3), wherein the number of configured information bits is 4 bits. If 0101, muting is performed only within the first and third duty cycles of four duty cycles of 40ms in total, and the fourth subframe in each duty cycle is the subframe to be muted. .

2-2) Method 2-2

비트 일 수 있다.In this case, instead of muting all the CSI-RS configuration subframes of the neighboring cells, only some of the CSI-RS configuration subframes of the neighboring cells are mutated in order to reduce an area where data cannot be transmitted due to the mutation. When the number of bits constituting the first data field is

It can be a bit.

It defines a specific period that is a multiple of the CSI-RS transmission period of the Serving Cell and an offset within a specific period. Muting is performed only for the CSI-RS transmission cycle of the Serving Cell corresponding to the offset within this period.

For example, when M = 4, the specific period is determined as a value corresponding to 2 times, 4 times, 8 times, and 16 times the CSI-RS transmission cycle of the serving cell. It is composed of 30 cases, 4 kinds of 2, 4 times, 8 kinds of 8 times, 16 kinds of 16 times, and the total number of bits is 5 bits.

For example, when the bit value of 5 bits is 0 to 1, two offsets are provided when the CSI-RS transmission cycle of the serving cell is twice, and when the bit is 2 to 5, the CSI-RS transmission of the serving cell is performed. 4 offsets for 4 times the duty cycle, 8 offsets for the CSI-RS duty cycle of the Serving Cell for 6 to 13, and 8 offsets for the 14 to 29 Serving 16 offsets are expressed when the CSI-RS duty cycle of the cell is 16 times.

Muting is performed only for the CSI-RS transmission cycle of the serving cell corresponding to the offset within the specific period, and the rest is not performed. That is, the subframe corresponding to the CSI-RS transmission offset within the CSI-RS transmission cycle of the serving cell represented by the specific period and the offset is determined as the subframe to be muted.

For example, if the CSI-RS transmission duty cycle of the Serving Cell is 10ms and the offset is 3, the CSI-RS is transmitted in the fourth subframe (subframe number 3), wherein the number of configured information bits is 5 bits. In case of 01010 (bit value is 10, which is 8 times a certain period and offset is 5), the fifth of 8 duty cycles that make 80ms, CSI-RS transmission duty cycle of Serving Cell is 8 times 10ms Muting is performed only in the duty cycle, and the fourth subframe in the duty cycle is the same as the subframe to be muted.

2-3) Method 2-3

Muting offset is not transmitted because it is same as CSI-RS transmission offset of Serving Cell (base station), and this is only because the duty cycle is a multiple of CSI-RS transmission cycle of Serving Cell (base station). It is a separate transmission method. For example, if the muting cycle is 1, 2, 4, 8, or 16 times the CSI-RS duty cycle of the Serving Cell (base station), these five cases consist of 3 bits. To transmit. (In the above, five types of multiple values are given, but the configuration and number of the multiple values may vary. For example, 1, 2, 4, and 8 times can be configured as 2 bits. It is possible to configure up to 8 multiples more than the above five values in each type and transmit them in 3 bits.) For example, the CSI-RS transmission duty cycle of the Serving Cell is 10ms and offset. In this case, the CSI-RS is transmitted in the fourth subframe (subframe number 3), wherein the configured number of information bits is 3 bits and 010 (bit value is 2, 000 is 1 times, 001 is 2 times, If 010 is configured as 4 times, ... this means that 4 times the duty cycle of the Serving Cell is the duty cycle), and 10ms which is the CSI-RS transmission duty cycle of the Serving Cell. 4 times 40ms becomes the duty cycle, and the muting subframe offset is 3 with the same subframe offset of Serving. It is.

3) Muting offset is Serving Cell (BS) of the CSI - RS transmission offset and the same, but, Muting period (duty cycle ) is Serving If not necessarily the RS transmission period (duty cycle) (Muting offset is the same for all neighboring cells of interest into a Muting However, Muting cycle (and duty cycle) is the case, which can be different from each other, - Cell (BS) of the CSI The information configured below is basically transmitted separately for each corresponding neighboring cell that is subject to all muting, but in order to reduce the total number of bits for muting signaling, the muting cycle and the muting offset are assigned to muting. It may be the same for all neighboring cells of interest, and the information configured below may be transmitted as the same for all neighboring cells of interest for muting.)

In this case, it can be divided into two detailed configurations, which will be described by dividing them into methods 3-1 and 3-2.

3-1) Method 3-1

In this case, the number of information bits configured as the first data field is' the number of neighboring cells (N) of each muting ing 2 bits or 3 bits (duty cycle) determined according to the number of types of muting periods. If there are four or less types, it is 2 bits, and if there are more types of duty cycles, and if there are eight or less types, it may be 3 bits). 'The duty cycle is determined according to the configured information bit value.

The CSI-RS of the Serving Cell (base station) is determined by the muting offset based on the modular value of the muting cycle (duty cycle), and corresponds to the muting offset in the muting cycle for each adjacent cell targeted for each muting. The subframe to be muted is determined from the subframe.

In addition, the information bits may be configured separately for each corresponding neighboring cell to be muted.

For example, if the number of information bits constituting the characteristic cell for muting is 2 bits, if the number '00' is 5ms, the duty cycle (duty cycle) is 5ms, if it is' 01 ', the muting cycle (duty cycle) is 10ms,' In case of 10 ', the muting cycle (duty cycle) is 20ms, and in case of' 11 ', the muting cycle (duty cycle) is 40ms.

If a 80ms or longer duty cycle is configured, the number of bits can be 3 bits.

At this time, if the configured bit value is '10', the muting cycle (duty cycle) is 20ms. In addition, if the CSI-RS transmission offset of the Serving Cell is 3, the fourth subframe (subframe number 3) every 20ms is the same as the subframe to be muted.

3-2) Method 3-2

bit)’이며, 선택적으로 ‘N ⅹ

bit’가 추가적으로 포함될 수 있다. 단, ‘N ⅹ

bit’는 전송되지 않을 수도 있다.In this case, the number of information bits composed of the first data field is' the number N of neighboring cells to be subjected to each muting ⅹ 2 bits (or 4 bits, 8 bits, ...,

bit) ', optionally' N ⅹ '

bit 'may be additionally included. However, 'N ⅹ

bit 'may not be transmitted.

For example, when M = 4, a bit map is 0 or 1 for each bit of information bits consisting of 2 bits, 4 bits, 8 bits, or 16 bits. Accordingly, each bit corresponds to 5ms (or 10ms), which is the smallest value of the duty cycle. That is, for a subframe corresponding to the value of Modular 5 (or 10) of the CSI-RS transmission offset of the Serving Cell (base station) every 5ms (or 10ms), if the bit value is 0, the data is muted. It is a method of transmitting a (of course, it can be configured to transmit data when 0 and muting when 1).

bit로 따로 시그널링을 해줄 수도 있다. 만약 M=4이며, 따로 시그널링 해 줄 수도 있는 비트 수는 2bit가 되며, 그 비트 값이 ‘00’이면 상기 구성되는 정보 비트 수는 2bit, ‘01’이면 4bit, ‘10’이면 8bit, ‘11’이면 16bit가 되는 것과 같다. 이 경우 제1데이터 필드로 구성되는 정보 bit는 Muting의 대상이 되는 각각의 해당 인접 셀에 대해서 각각 따로 구성이 될 수 있다.Also, how many bits of information bits are constructed

Signaling can also be done separately. If M = 4, the number of bits that can be signaled separately is 2 bits. If the bit value is '00', the configured information bits are 2 bits, '01' is 4 bits, '10' is 8 bits, and '11'. 'Is equivalent to 16 bits. In this case, the information bit configured as the first data field may be configured separately for each corresponding neighboring cell to be muted.

For each bit value of the configured information bit, the CSI-RS transmission offset of the Serving Cell (base station) is modulated every Muting cycle corresponding to 5ms (or 10ms) only when the bit value is 0. The subframe corresponding to the value 5 (or 10) is determined as the subframe to be muted.

For example, if the number of information bits constituting the characteristic cell targeted for muting is 4 bits and 0101, muting is performed only within the first and third duty cycles among four muting duty cycles which total 5 ms * 4 = 20 ms. When the CSI-RS transmission offset of the Serving Cell (base station) is 8 (10 ms for the CSI-RS transmission cycle), the fourth subframe corresponding to 3 corresponding to the modular value of 5 subframe number 3) is the same as the subframe to be muted.

4) Muting cycle ( duty cycle ) is Serving Of Cell (BS) CSI - RS transmission period (duty cycle ), but with Muting offset is Serving If the cell (base station) is different from the CSI - RS transmission offset (Muting cycle (duty cycle) is the same for all neighboring cells subject to muting, but the muting offset may be different from each other. Is transmitted separately for each neighboring cell that is subject to all muting)

In this case, the number of information bits included in the first data field is 'the number of adjacent cells (N) ⅹ 2 to 4 bits of each Muting object').

The duty cycle of the CSI-RS of the Serving Cell (base station) is determined by the duty cycle, and the muting offset is determined by the bit value received in each duty cycle. For example, if the duty cycle (duty cycle) is 5ms, the remaining four subframes are represented by 2bit information except for the subframe through which the PSS / SSS is transmitted, and the muting offset is determined from this value. If the muting cycle (duty cycle) is 10ms, the remaining eight subframes are expressed as 3bit information except the subframe through which the PSS / SSS is transmitted, and if the muting cycle (duty cycle) is 20ms, PSS / SSS is transmitted The remaining 16 subframes except the subframe are represented by 4 bit information. Subframes subject to muting are determined from subframes corresponding to the muting offsets within the muting period for each corresponding neighboring cell to be muted.

The information bits may be configured separately for each corresponding neighboring cell to be muted.

For example, the number of information bits constituting the characteristic cell to be muted is 3 bits, and the fifth subframe excluding the PSS / SSS, whose value is '010', is determined as the muting offset. When the duty cycle of the CSI-RS of the serving cell (base station) is 10ms, the fifth subframe (subframe number 4) becomes the subframe to be muted every 10ms.

5) Muting cycle ( duty cycle ) and Muting offset is Serving CSI-RS transmission period of the Cell (BS) (duty cycle ) and the transmission offset may differ from each other (duty cycle and muting offset may be different for each corresponding neighboring cell that is the target of all muting. Are transmitted separately for each corresponding neighboring cell)

’가 되는 구성이다.In this case, the number of information bits consisting of the first data field is' the number of adjacent cells (N) of each muting target.

It becomes a configuration.

In this configuration, the muting cycle and the muting offset are determined according to the configured information bit value. For example, in case of M = 3, each of 3, 5ms, 10ms, and 20ms, consists of 28 cases of 4, 8 and 16 subframe offsets except PSS / SSS. The total number of bits is 5 bits.

For example, if the bit value of 5 bits is 0 to 3, when the duty cycle is 5ms and 4 subframe offsets, and when 4 to 11, the duty cycle is 10ms and the subframe offset In case of 8, 12 ~ 27, when the duty cycle is 20ms and 16 subframe offsets are expressed. In case of M = 4, 4, 8, 16, and 32 subframe offsets, except PSS / SSS, for each of 4 cycles of 5ms, 10ms, 20ms, and 40ms are 60 cases in total. The total number of bits is 6 bits.

For example, if the bit value of 6bit is 0 ~ 3, when the duty cycle is 5ms and 4 subframe offsets, and when 4 ~ 11, the duty cycle is 10ms and 8 subframe offsets In the case of 12 ~ 27, when the duty cycle is 20ms and 16 subframe offsets, in the case of 28 ~ 59, when the duty cycle is 40ms and 32 subframe offsets are expressed. Subframes subject to muting are determined from subframes corresponding to the muting offsets within the muting period for each corresponding neighboring cell to be muted.

In addition, the information bits may be configured separately for each corresponding neighboring cell to be muted.

For example, if the number of information bits constituting the characteristic cell for muting is 5 bits and '01101' (bit value is 13), the muting cycle is 20ms and the muting offset is 1. In the case of ~ 27, 16 subframe offsets are represented when the duty cycle is 20ms, that is, offset 0 when 12 and offset is 1 when 13). Therefore, every 20ms for the corresponding cell. The second subframe excluding PSS / SSS (subframe number 2, subframe number 0 is the subframe to which PSS / SSS is mapped) becomes the subframe to be muted.

The foregoing describes the method of configuring the first data field among the muting information used in the first step of FIG. 15.

Each of these schemes is not individually determined in each case, but only one is selected and applied according to a system configuration and standardized method for CSI-RS, and each case may include a different case (for example, Method 5 can be seen as a generalized case, including other methods).

Various ways that can constitute the first step can be generally summarized again as follows, and one of the following four ways can be applied to the system for the present invention.

A. There is one information to be configured, and the number of bits to be configured is 0 bit

Muting cycle → Same as CSI-RS transmission cycle to Serving Cell

Muting offset → Same as CSI-RS transmission offset to Serving Cell

bit (

bit는 전송되지 않을 수도 있음) (상기 방법 중 2-1번 방법에 해당)B. There is one piece of information, and the number of bits consists of 2 bits, 4 bits, 8 bits,…. Or 2 ^M bit and

bit (

bit may not be transmitted) (corresponding to method 2-1 of the above method)

-Muting cycle (duty cycle) → Same as the CSI-RS transmission cycle (duty cycle) to the Serving Cell, but the Muting will be determined in a cycle that is a multiple of the CSI-RS transmission cycle (duty cycle) to the Serving Cell. Muting is performed only when the bit value is 0 (or 1).

For example, if M = 4, the number of bits configured is one of 2 bits, 4 bits, 8 bits, and 16 bits (an additional 2 bits can be transmitted to indicate whether the number of configured bits is 2 bits, 4 bits, 8 bits, or 16 bits). Each bit is the same as one CSI-RS transmission period in the Serving Cell. That is, if the configured number of bits is 4 bits and '1001', and the CSI-RS transmission period is 10ms in the Serving Cell, only the second and third 10ms intervals of the total 40ms are actually muted.

Muting offset → Same as CSI-RS transmission offset to Serving Cell

bit (

bit는 전송되지 않을 수도 있음) (상기 방법 중 3-2번 방법에 해당)C. A plurality of pieces of information are configured for each neighboring cell (muted and transmitted separately for each neighboring cell), and the number of bits configured for each neighboring cell is 2 bits, 4 bits, 8 bits,... Or 2 ^M bit and

bit (

bit may not be transmitted) (corresponding to method 3-2)

-Muting cycle (duty cycle) → Same as the smaller value (5ms or 10ms) of the CSI-RS duty cycle, but the multiple of the smaller value (5ms or 10ms) of the CSI-RS duty cycle Muting is judged in a cycle that is performed. Muting is performed only when the configured bit value is 0 (or 1).

For example, if M = 4, the number of bits configured is one of 2 bits, 4 bits, 8 bits, and 16 bits (an additional 2 bits can be transmitted to indicate whether the number of configured bits is 2 bits, 4 bits, 8 bits, or 16 bits). Each bit is equal to one small value (5ms or 10ms) of the CSI-RS duty cycle. That is, if the number of bits configured is 4 bits and '1001', and the small value of the CSI-RS duty cycle is 5ms, the muting is substantially performed only in the second and third 5ms intervals of the total 20ms.

Muting offset → The CSI-RS transmission offset of the serving cell is the same as the modular value with a small value (5ms or 10ms) during the CSI-RS transmission cycle. For example, when the CSI-RS transmission offset of the Serving Cell is 8 and the small value of the CSI-RS transmission cycle of the Serving Cell is 5ms, the Muting offset is (8 mod 5) = 3.

(상기 방법 중 5의 일반적인 경우에 해당)D. A plurality of pieces of information are configured for each neighboring cell (muted and transmitted separately for neighboring cells), and the number of bits configured for each neighboring cell

(Corresponds to general case of 5 of the above methods)

Muting cycle (duty cycle) and Muting offset → It is a case of determining the duty cycle (duty cycle) and muting offset according to the configured information bit value. For example, in case of M = 3, each of three cycles of 5ms, 10ms and 20ms consists of 28 cases of 4, 8 and 16 subframe offsets except PSS / SSS. The total number of bits is 5 bits.

For example, if the bit value of 5 bits is 0 to 3, when the duty cycle is 5ms and 4 subframe offsets, and when 4 to 11, the duty cycle is 10ms and the subframe offset In case of 8, 12 ~ 27, when the duty cycle is 20ms and 16 subframe offsets are expressed.

In case of M = 4, 60 cases of 4, 8, 16, and 32 subframe offsets except PSS / SSS for 4 types of duty cycle are 5ms, 10ms, 20ms, and 40ms. The total number of bits is 6 bits. For example, if the bit value of 6bit is 0 ~ 3, when the duty cycle is 5ms and 4 subframe offsets, and when 4 ~ 11, the duty cycle is 10ms and the subframe offset 8 In the case of 12 ~ 27, when the duty cycle is 20ms and 16 subframe offsets, in the case of 28 ~ 59, when the duty cycle is 40ms and 32 subframe offsets are expressed.

In the case of M = 5, 4, 8, 16, 32, 64 types of duty cycles of 5ms, 10ms, 20ms, 40ms and 80ms are excluded except PSS / SSS. The subframe offset consists of 124 cases in total, and the total number of bits is 7 bits in total.

In the case of M = 6, in the same manner, the duty cycle is 5ms, 10ms, 20ms, 40ms, 80ms, 160ms, 4, 8, 16, 32, except PSS / SSS, respectively. A total of 252 cases of 64 and 128 subframe offsets are configured, and the total number of bits is 8 bits.

M may be larger depending on the system configuration. Subframes subject to muting are determined from subframes corresponding to the muting offsets within the muting period for each corresponding neighboring cell to be muted.

In the above method, an offset may be defined for all subframes within one radio frame without excluding subframes including PSS / SSS, and in this case, the number of configured bits may be slightly increased. For example, in the above example, if M = 5, 7bit is configured with a total of 124 cases except for a subframe including PSS / SSS, but the duty cycle is 5ms, 10ms, 20ms, 40ms in the same manner. , 5, 10ms, 5, 10, 20, 40, and 80 subframe offsets for all the subframes within the period can be composed of a total of 155 cases, where the total number of bits is 8 bits.

● Stage 2

Hereinafter, each case of the second step of determining a muting pattern group or a specific specific muting pattern in one subframe and generating a second data field indicating the same will be described.

In the second step, the second-first method of configuring the second data field to directly display information on a specific muting pattern without information on the muting pattern group, and the second data field to indicate only the muting pattern group The 2-1 scheme may be divided into the 2-2 scheme, and the 2-1 scheme to display only a specific muting pattern may be subdivided into one of the A, B, and C schemes.

However, the present invention is not limited to this division scheme, and may include all manners of configuring the second data field to represent one or more of a muting pattern group and a specific muting pattern so as to indicate a muting region in a muting subframe. .

1) Method 2-1: configure the second data field to represent only the muting pattern

In general, when a muting pattern group is identified, even when two or four antenna ports are regarded as having eight antenna ports, the area to be muted becomes larger. That is, resource elements (REs) to be muted become large, but overhead for configuring and signaling muting information is reduced.

As described above, in the 2-1 method, when the muting pattern is directly detected, the muting pattern is immediately identified without identifying the muting pattern group.

The muting pattern group is a pattern group composed of eight REs, such as when the CSI-RS antenna port is eight of the CSI-RS patterns.

In the case of the CSI-RS in the case of normal CP, which is basically applied to both FS1 (FDD) and FS2 (TDD), when the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. Muting pattern group is also one of five because CSI-RS patterns are defined. For extended CP, if the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. Muting pattern group is one of four because it is defined.

For CSI-RS applied as an additional option in FS2 (TDD) as shown in FIGS. 11 and 13, when the number of CSI-RS antenna ports is 8 for one subframe for a normal CP, a total of 3 Muting pattern group is one of three because CSI-RS patterns are defined, and if CSI-RS antenna port number is 8 for one subframe in extended CP, total 7 CSI-RS patterns are defined. One of seven.

Three detailed schemes A to C for implementing the 2-1 scheme under such conditions are described in detail below.

A. Method of directly displaying the muting pattern 1: Method of configuring 5-6 bits for each adjacent cell to be muted

In the method 2-1, in the method A, the number of information bits constituting the second data field may be the number N of adjacent cells to be subjected to 5-bit or 6-bit ⅹ muting to indicate each of the muting patterns. .

More specifically, the CSI-RS is applied to both FS1 (FDD) and FS2 (TDD) by default, and the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. 3. In this case, since a total of five CSI-RS patterns are defined, the total number of muting patterns is 5 for 8 antenna ports, 10 for 4 antenna ports, and 20 for 2 antenna ports. Accordingly, the second data field may be configured to represent a total of 35 muting patterns in 6 bits.

For example, for the bit values 0 to 63 when expressed as 6 bits, 5 muting patterns for 8 antenna ports when the bit values are 0 to 4, and 4 antenna ports for the bit values 5 to 14 10 muting patterns in the case of a dog, and 15 to 34 bit values represent 20 muting patterns in the case of two antenna ports, and the remaining bit values of 35 to 63 are reserved.

In addition, for the CSI-RS in the case of extended CP, which is basically applied to both FS1 (FDD) and FS2 (TDD), when the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. Since four CSI-RS patterns are defined, the total number of muting patterns is four for eight antenna ports, eight for four antenna ports, and sixteen for two antenna ports. Therefore, the second data field may be configured to represent 28 muting patterns in 5 bits. For example, for the bit values 0 to 31 represented by 5 bits, 4 muting patterns for 8 antenna ports when the bit values are 0 to 3, and 4 antenna ports for 4 to 11 bits. Eight Muting Patterns in case of dogs and 16 Muting Patterns in case of two antenna ports when bit values are 12 to 27, and the remaining bit values 28 to 31 are reserved.

For CSI-RS applied as an additional option in FS2 (TDD) as shown in FIGS. 11 and 13, in case of normal CP, when the number of CSI-RS antenna ports is 8 for one subframe, a total of 3 Since three CSI-RS patterns are defined, the total number of muting patterns is three for eight antenna ports, six for four antenna ports, and twelve for two antenna ports. Accordingly, the second data field may be configured to represent a total of 19 muting patterns with 5 bits by the above method.

In case of the extended CP for the CSI-RS applied as an optional option in the FS2 (TDD), when the number of CSI-RS antenna ports is 8 for one subframe, a total of seven CSI-RS patterns are defined. Therefore, the total number of muting patterns is 7 for 8 antenna ports, 14 for 4 antenna ports, and 28 for 2 antenna ports. Therefore, the second data field may be configured to represent 49 muting patterns in 6 bits in the same manner as described above. These second data fields may be configured differently for each adjacent cell that is subject to muting.

In addition, in the above, the muting information is configured and transmitted by dividing the case where it is basically applied to FS1 and FS2 and the case where it is applied as an option only to FS2. However, for convenience, the two cases can be combined and transmitted at the same time. have. For example, in case of Normal CP, 56 types of 6 bits can be transmitted by combining 35 types when applied to FS1 and FS2 as basic (general) and 21 items when applied to FS2 as an option. In this case, as mentioned in FS2, 56 types are composed of 6 bits, but in FS1, there are only patterns that are applied to the basic (general), so in this case, only 35 can be configured in 6 bits. For FS1, muting information can also be configured with 6 bits in consideration of 56 kinds.

In the case of Extended CP, the pattern when it is already applied as an option only to FS2 includes the pattern when it is applied to FS1 and FS2 by default, so both FS1 and FS2 are the same. In consideration of the branching, the muting information may be configured in 6 bits.

B. Method of Directly Displaying Muting Pattern 2: Method of Composing 5 Bits for Each Adjacent Cell Subject to Muting

In the method B of the method 2-1, the number of information bits constituting the second data field may be 'the number N of adjacent cells to be subjected to 5-bit muting'.

More specifically, when the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. 3 for the CSI-RS in the case of the normal CP is applied to both FS1 (FDD) and FS2 (TDD). Since a total of five CSI-RS patterns are defined, the total number of muting patterns is 5 for 8 antenna ports, 10 for 4 antenna ports, and 20 for 2 antenna ports. Therefore, a total of 35 muting patterns are defined. Since the CSI-RS of the neighboring cell that is the target of muting does not transmit the CSI-RS as a pattern that includes or includes at least the CSI-RS transmitted by the serving cell, Therefore, the muting pattern of the adjacent cell that is the subject of substantial muting can be defined.

For example, if a Serving cell transmits CSI-RS to eight antenna ports, this CSI-RS pattern for eight antenna ports cannot be a CSI-RS pattern of an adjacent cell to be muted. Therefore, among the total 35, 7 types included in the CSI-RS pattern of this Serving cell (the pattern included in the CSI-RS pattern of the corresponding Serving cell when 8 antenna ports are 1 pattern when 8 antenna ports are included, and the antenna 2 patterns for 4 ports and 4 patterns for 2 antenna ports, and the total number of patterns is 7)) cannot be the CSI-RS pattern of an adjacent cell to be subjected to muting. The second data field may be configured to represent the remaining 28 muting patterns in 5 bits.

In addition, when the serving cell transmits the CSI-RS to four antenna ports, the CSI-RS pattern for the four antenna ports cannot be the CSI-RS pattern of the neighboring cell to be muted. Therefore, 4 out of 35 CSI-RS patterns included or included in this Serving cell (CSI-RS pattern included in the corresponding Serving cell in case of 4 antenna ports are 1 pattern in case of 4 antenna ports) And two patterns in the case of two antenna ports, and a pattern including the CSI-RS pattern of the corresponding serving cell in the case of four antenna ports is one pattern including the eight antenna ports. Therefore, the total number of total patterns is 4)) cannot be the CSI-RS pattern of the neighboring cell that is the target of muting, and configures the second data field so that the remaining 31 muting patterns are separated by 5 bits. can do.

In addition, when the Serving cell transmits the CSI-RS to the two antenna ports, the CSI-RS pattern for the two antenna ports cannot be the CSI-RS pattern of the adjacent cell to be muted. Therefore, among the 35 types, three types including the CSI-RS pattern of the Serving cell (the pattern included by the CSI-RS pattern of the corresponding Serving cell when two antenna ports are one is one pattern when two antenna ports are included). In addition, the pattern including the CSI-RS pattern of the corresponding serving cell in the case of two antenna ports is one pattern including the one of eight antenna ports and one pattern including four of the antenna ports. Therefore, the total number of total patterns is 3). The second data field may not be the CSI-RS pattern of the neighboring cell to be muted, and is represented by 5 bits for the remaining 32 muting patterns. Can be configured.

In addition, for the CSI-RS in the case of the extended CP, which is basically applied to both the FS1 (FDD) and the FS2 (TDD), a total of 4 when the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. CSI-RS patterns are defined. In this way, 21 if the Serving cell transmits the CSI-RS to 8 antenna ports except 21 of the total 28, 4 out of 28 if the Serving cell transmits the CSI-RS to 4 antenna ports If the 24 kinds of serving cells except the branches transmit the CSI-RS with 2 antenna ports, the second data field may be configured to represent 25 kinds except the 3 kinds of the total 28 kinds by 5 bits. Likewise, you can organize information using just 28 bits of 5 bits.

This configuration excludes the case of the CSI-RS configuration applied as the additional option of FIGS. 10 to 13.

The second data field is configured for each adjacent cell to be muted.

C. How to Display Muting Patterns Immediately 3: Composed of 12-28 Bit Bitmaps

In the C-1 method of the 2-1 method, the information bit number constituting the second data field may be configured as one bit value of '12 to 28 bits in total '.

The second data field configuration in each case will be described below.

Basically applied to both FS1 (FDD) and FS2 (TDD), and for the CSI-RS in the case of normal CP, as shown in Figure 3 when the total number of CSI-RS antenna ports for a single subframe, as shown in FIG. -RS patterns are defined, in which case there are 20 CSI-RS patterns when there are two antenna ports.

When the bitmap is composed of 20 bits, the information about the RE to be mutated in one subframe can be configured regardless of the number of adjacent cells that are subject to muting.

In other words, for each of the 20 patterns for two antenna ports consisting of two REs, the bitmap information is 0 and the data is transmitted when 1 is transmitted. In case of sending data, in case of 1, it can be muted). If the number of CSI-RS antenna ports of the neighboring cells to be muted is 8, the number of 4 CSI-RS antenna ports is composed of 2, so all of the bitmap values for these 4 should be zero. Expression In addition, if the number of CSI-RS antenna ports of the adjacent cells to be muted is 4, the number of two CSI-RS antenna ports is 2, so the bitmap values for the two are set to 0. Expression

For CSI-RS in the case of extended CP, which is basically applied to both FS1 (FDD) and FS2 (TDD), if the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. The CSI-RS pattern is defined. In this case, since the number of patterns for transmitting the CSI-RS to the two antenna ports is 16 in total, it can be configured as 16-bit bit map information in the same manner as described above.

As shown in FIG. 11, for the CSI-RS applied as an additional option in the FS2 (TDD), when the number of CSI-RS antenna ports is 8 for one subframe in the case of normal CP, a total of three CSI-RS patterns Is defined. At this time, since the total number of patterns for transmitting the CSI-RS to the two antenna ports is 12 kinds, it can be configured as 12-bit bit map information in the same way as described above.

As shown in FIG. 13, for the CSI-RS applied as an additional option in the FS2 (TDD), when the number of CSI-RS antenna ports is 8 for one subframe in the case of the extended CP, a total of 7 CSI-RSs The pattern is defined. At this time, since the number of patterns for transmitting the CSI-RS to two antenna ports is 28 in total, it can be configured as 28-bit bitmap information in the same manner as described above.

In addition, in the above, the muting information is configured and transmitted by dividing the case where it is basically applied to FS1 and FS2 and the case where it is applied as an option only to FS2. However, for convenience, the two cases can be combined and transmitted at the same time. have. In other words, in case of Normal CP, 32 kinds of 32-bit bitmaps can be transmitted by combining 20 kinds of FS1 and FS2 that are applied to FS2 and 12 kinds that are applied only to FS2 as an option. In this case, as mentioned in FS2, 32 types are composed of 32-bit bitmaps, but in FS1, there are only 20 basic bit-maps. In order to apply the same system of FS2, muting information can be configured with 32-bit bitmap considering 32 kinds in FS1.

In the case of Extended CP, the pattern when it is already applied as an option only to FS2 includes the pattern when it is applied to FS1 and FS2 by default, so both FS1 and FS2 are the same as above. In consideration of the branching, the muting information may be configured by a bitmap of 28 bits.

2) Method 2-2: Configure the second data field to represent only the muting pattern group

In the second-2 scheme of configuring the second data field to represent only the muting pattern group, the second data field is basically applied to both '3 to 7 bits' (FS1 (FDD) and FS2 (TDD) and is normal CP. Is 5 bits).

In this 2-2 method, the method does not mute only a specific muting pattern in a muting pattern group according to the number of antenna ports, but mutes all REs in a predetermined muting pattern group.

The second data field configuration in each case will be described below.

Basically applied to both FS1 (FDD) and FS2 (TDD), and for the CSI-RS in the case of normal CP, as shown in Figure 3 when the total number of CSI-RS antenna ports for a single subframe, as shown in FIG. -RS pattern is defined. In this case, since the number of patterns for transmitting the CSI-RS to 8 antenna ports is 5 in total, it is possible to configure the second data field with bitmap information in 5 bits, and the number of neighboring cells to be mutated. Regardless, it is possible to configure information about RE to be mutated in one subframe. That is, it consists of 5bit bitmap for each of 5 patterns of 8 antenna ports composed of 8 REs, muting if 0, and sending data when 1 (in contrast, 0 when data is 0). If it is 1, you can Muting).

In this case, when the muting region is identified by the muting pattern group, each adjacent cell that is the target of muting is regarded as having 8 antennas even when sending CSI-RS to 2 and 4 antenna ports. Practically, much more is the area to be muted.

That is, there is a problem that the area for transmitting data is reduced because the RE area to be mutated becomes large, but the overhead of configuring and signaling muting information is reduced.

For CSI-RS in the case of extended CP, which is basically applied to both FS1 (FDD) and FS2 (TDD), if the number of CSI-RS antenna ports is 8 for one subframe as shown in FIG. The CSI-RS pattern is defined. In this case, since the total number of patterns for transmitting the CSI-RS to 8 antenna ports is 4 in total, the second data field may be configured with 4 bit bit map information as described above.

As shown in FIG. 11, for the CSI-RS applied as an additional option in the FS2 (TDD), when the number of CSI-RS antenna ports is 8 for one subframe in the case of normal CP, a total of three CSI-RS patterns Is defined. In this case, since the number of patterns for transmitting the CSI-RS to eight antenna ports is three in total, the second data field may be configured with 3 bit bit map information in the same manner as described above.

As shown in FIG. 13, for the CSI-RS applied as an additional option in the FS2 (TDD), in the case of the extended CP, when the number of CSI-RS antenna ports is 8 for one subframe, a total of seven CSI-RS patterns Is defined. In this case, since the number of patterns for transmitting the CSI-RS to 8 antenna ports is 7 in total, the second data field may be configured with 7 bit bit map information in the same manner as described above.

In the above, a method of muting all REs in a predetermined muting pattern group is applied, not a method of muting only a specific muting pattern in a muting pattern group. In this case, the reference muting pattern group is based on eight CSI-RS antenna ports. However, this may be based on four CSI-RS antenna ports.

The generated muting information may be transmitted through higher level signaling such as RRC, may be transmitted dynamically through the PDCCH of the L1 layer, and in some cases, may be signaled through the MAC of the L2 layer. .

The muting area determination and muting information generation of this embodiment may be selectively adopted in one or more of the above-described cases depending on the specification of the communication system to which the present embodiment is applied.

For example, according to the type of communication system, one or more of the various ways of constructing the first and second stages may be combined to form the present invention.

In other words, the present invention does not adopt all the detailed methods of the first and second steps described above, but rather the specification of the communication system, the configuration of the CSI-RS, the CSI-RS pattern, the number of CSI-RS antenna ports, and the CSI. One or more of the various schemes that constitute the first and second stages may be combined according to types such as -RS transmission duty cycle and CSI-RS transmission subframe offset.

17 is a flowchart illustrating a method of obtaining channel information at a terminal using muting information according to the present embodiment.

The method for acquiring channel information according to the present embodiment is to obtain channel information by receiving CSI-RS signals from two or more cells (base stations), which is generally performed in a terminal or a UE, but is not limited thereto.

The channel state acquisition method according to the present embodiment includes a first data field indicating a muting duty cycle and a muting offset from a serving cell among two or more cells, one of a muting pattern group and a specific muting pattern in one muting subframe. Receiving the muting information including the second data field indicating the above (S1705), receiving a CSI-RS in consideration of muting (S1710), and transmitting the data of the serving cell using the muting information Confirming the muting region in the resource space for and identifying the CSI-RS transmission region of the neighboring cell corresponding thereto (S1715), decoding the CSI-RS of the serving cell and the neighboring cell in consideration of the muting region; It may be configured to include a step (S1720) to obtain a channel state by the measurement (estimation).

Receiving the CSI-RS in consideration of muting in step S1710, specifically, the part muted by the muting information in the physical space (PDSCH, Physical Downlink Shared Channel) for data transmission of the CSI-RS of the serving cell and the serving cell This means receiving the CSI-RS of the neighbor cell transmitted from the resource region of the neighbor cell corresponding to the region.

The muting information received from the serving cell in S1705 is information indicating an area in which data should not be superimposed with the CSI-RS of the neighbor cell, and may be composed of the first and second data fields described with reference to FIGS. 2 to 16. have.

The above-described steps S1705 and S1710 may be configured in some cases, or may be implemented in one.

The CSI-RS signal received from the serving cell and the neighboring cell is matched with a reference signal (CSI-RS of the serving cell) generated in the area allocated in the serving cell to transmit the CSI-RS or the serving cell so as to match the aforementioned muting information. Reference signal generated in the resource region of neighboring cells corresponding to the region to which muting is applied in which no data is transmitted or zero power is transmitted in a resource space (PDSCH) for transmitting data of a CSI-RS of a neighboring cell. )to be.

The checking of the muting region in S1715 may include determining a muting period and a muting offset by using the first data field value of the received muting information to determine a subframe in which the muting region exists, and using the second data field value. The method may include determining a muting pattern group or a specific muting pattern in the corresponding muting subframe, and determining a muting region using the determined muting pattern group or muting pattern group, but are not limited thereto.

In operation S1720 of acquiring channel states of the serving cell and the neighboring cell in consideration of a muting region, the terminal decodes the data received from the serving cell in a manner such that the decoding of the RE, which is a muting region, is not taken into consideration when decoding. After decoding the CSI-RS of the neighbor cell received from the region corresponding to the muted resource region and the CSI-RS of the previously received serving cell, the reference signal may be decoded and the channel state may be measured therefrom. This not only improves the efficiency of decoding the CSI-RS, but also accurately decodes the CSI-RS of each cell by eliminating interference with the CSI-RS of adjacent cells, thereby enabling accurate channel estimation. .

18 is a block diagram of a CSI-RS muting information transmission apparatus according to the present embodiment.

The CSI-RS muting information transmission apparatus according to the present embodiment is generally implemented in or coupled with a serving cell or a serving base station in a multi-cell environment, but is not limited thereto.

The CSI-RS muting information transmitting apparatus according to the present embodiment includes a CSI-RS pattern, a number of CSI-RS antenna ports, a CSI-RS transmission duty cycle, and a CSI-RS transmission subframe from one or more adjacent cells in a multi-cell environment. A neighbor cell information receiver 1810 that receives neighbor cell information including one or more of frame offset information, and a time required for muting by overlapping with the CSI-RS of the neighbor cell in its resource space based on the neighbor cell information; A muting region determiner 1820 that determines a muting region that is a frequency / frequency region, a first data field indicating the muting region and a muting duty cycle and a muting offset, and a muting pattern in one muting subframe A muting information generator 1830 for generating muting information including a second data field indicating at least one of a group and a specific muting pattern, and a terminal (UE) for receiving the generated muting information by CSI-RS. It may be configured to include a muting information transmitter 1840 for transmitting.

The neighbor cell information receiving unit 1810 may transmit a CSI-RS pattern and a CSI of each neighbor cell from neighbor cells (Cell B and Cell C of FIG. 14) that should transmit their CSI-RS to a specific UE in a multi-cell environment such as CoMP. -Receives a function of receiving one or more information among the number of RS antenna ports, CSI-RS transmission duty cycle, and CSI-RS transmission subframe offset information.

The muting region determiner 1820 performs a function of determining a muting region, which is a time / frequency region that requires muting by overlapping with the CSI-RS of the neighbor cell in its resource space based on the neighbor cell information received from the neighbor cell. do.

The muting information generator 1830 generates muting information that may indicate the muting area determined by the muting area determiner. More specifically, as described with reference to FIGS. 2 to 16, a muting duty cycle and The final muting information may be generated by generating and combining a first data field indicating a muting offset, and a second data field indicating one or more of a muting pattern group and a specific muting pattern in one muting subframe.

The first and second data fields may be determined according to a combination of one or more of the first and second steps as described with reference to FIG. 16, and detailed descriptions thereof will be omitted to avoid duplication.

As an example of such muting information, it is assumed that the communication system to which the present embodiment is applied has the following conditions.

1) Stage 1 condition: Muting offset is equal to CSI-RS transmission offset of Serving Cell (base station) (assume offset is 3), Muting duty (duty cycle) is CSI-RS transmission cycle of Serving Cell (base station) is a multiple of (duty cycle), M = 4, and how many bits of information bits comprise the first data field If signaling is performed separately with = 2bit (as a result, it corresponds to the 2-1 method of the first step described above, total 6 bits)

2) Stage 2 condition: The second data field is configured to directly indicate a specific muting pattern, and is basically applied to both FS1 (FDD) and FS2 (TDD) and is a normal CP, and the CSI- of the adjacent cell. Suppose that the number of RS antenna ports is 8 and a total of 35 patterns (eight antennas, five antennas, four antennas, and two antennas 20) are represented by 6 bits (as a result, 2-step 2-described above). Corresponds to method A of method 1; assuming that pattern b is a muting pattern with 6 bits in total and 8 antennas, expressed as 000001)

In such a condition, the muting information includes a first data field bit value of 6 bits and a second data field bit value of 6 bits, and may be configured as shown in FIG. 19.

That is, FIG. 19 shows an example of a data format of muting information according to the present embodiment.

Assuming the first and second step conditions described above, the muting information 1900 according to the present embodiment includes a first data field region 1910 consisting of six bits of 101010 and a second data field region consisting of six bits of 000001. And 1920.

To explain the meaning of each data field value in detail, the first data field value, which is 6 bits of 101010, is again a 2-bit value (log ₂ M = 2) of " 10 " representing the configuration bit number (M = 4). It can be divided into a 4-bit region of "1010" indicating the muting period and the muting offset.

As a result, the first data field value 101010 has a muting period of 40 ms, which is four times the CSI-RS transmission period (10 ms) of the serving cell, and there is a muting subframe within the second and fourth CSI-RS transmission periods. Display. (Assuming 0 means muting ON and 1 means muting OFF.) In addition, since the muting offset is 3 according to the first stage condition, the fourth subframe (subframe number within the second and fourth CSI-RS transmission periods). 3) becomes a muting subframe.

In addition, since the second data field value is 000001, it is basically applied to both FS1 (FDD) and FS2 (TDD), and in the case of normal CP, a total of 35 patterns (eight antennas, five antennas, four antennas, and ten antennas) are possible. The number of CSI-RS antenna ports of the neighboring cells corresponds to eight among the two 20 kinds) and represents the pattern b which is the second pattern among the total of five CSI-RS patterns of FIG. 3. (The patterns a to e of the eight antennas according to FIG. 3 are represented as 000000, 000001, 000010, 00011, 000100, and the patterns a to j of the four antennas according to FIG. 4 are designated as 000101, 000110, 000111, ..., etc. Assuming you want to display them in order)

It is assumed that the muting information as shown in FIG. 19 considers only one neighboring cell, and when muting information is separately configured for each of two or more neighboring cells, muting information corresponding to the number N of neighboring cells may be generated.

20 is a diagram illustrating a frame and resource space configuration indicating a state in which a CSI-RS of an actual serving cell is muted by the muting information of FIG. 19.

According to the muting information of FIG. 19, a fourth subframe (subframe number 3) becomes a muting subframe within the second and fourth CSI-RS transmission periods, and the resource space corresponds to pattern b of FIG. 3. The REs (indicated by dark shades in FIG. 20) become muting regions, thereby muting the data without allocating the data to the region. This is shown in FIG.

21 is a configuration diagram of a channel state obtaining apparatus using muting information according to the present embodiment.

The apparatus for acquiring channel information according to the present embodiment obtains channel information by receiving CSI-RS signals from two or more cells (base stations), which is generally implemented in a terminal or a UE or is configured in association with the same, but is limited thereto. It is not.

The channel state obtaining apparatus according to the present embodiment includes a first data field indicating a muting duty cycle and a muting offset from a serving cell among two or more cells, one of a muting pattern group and a specific muting pattern in one muting subframe. A muting information receiver 2110 for receiving muting information including a second data field indicating the above, a CSI-RS receiver 2120 for receiving a CSI-RS signal considering muting from the serving cell and an adjacent cell; Muting in which the CSI-RS signal of an adjacent cell is transmitted without being inputted (or receiving data with zero power) in a resource downlink (PDSCH, Physical Downlink Shared Channel) for data transmission in consideration of the muting information A muting area checking unit 2130 for checking an area, and a channel state obtaining unit 2140 for decoding a CSI-RS signal to obtain a channel state in consideration of the muting area; It can be configured to include.

The muting information received from the serving cell is information indicating an area in which data should not be superimposed with the CSI-RS of the neighbor cell and may be composed of the first and second data fields described with reference to FIGS. 2 to 16.

The muting information receiver 2110 receives the muting information generated and transmitted by the serving cell according to a combination of one or more of the above-described first to second steps, and the muting information is illustrated in FIG. 19 and the like. It may have the same form, but is not limited thereto.

The CSI-RS receiver 2120 functions to receive the CSI-RS signal from the serving cell and the neighbor cell, and the CSI-RS signal received from the serving cell and the neighbor cell is already transmitted from the serving cell in order to transmit the CSI-RS. In order to match the reference signal generated in the allocated region (CSI-RS of the serving cell) or the above-mentioned muting information, data is not transmitted or transmitted at zero power in a resource space (PDSCH, Physical Downlink Shared Channel) for data transmission of the serving cell. A reference signal (CSI-RS of a neighboring cell) generated in a resource region of neighboring cells corresponding to a region to which muting is applied.

The muting area checking unit 2130 performs a function of checking a muting area for the serving cell using the muting information received from the serving cell, and more specifically, using the first data field value of the received muting information. Determining a subframe in which the muting region exists by checking the muting period and the muting offset; determining a muting pattern group or a specific muting pattern in the muting subframe using the second data field value; The muting region may be determined using a muting pattern or a muting pattern group. However, the muting region may not be limited thereto. For example, the muting region may be identified according to the principles illustrated in FIGS. 19 and 20.

In consideration of the muting region, the channel state obtaining unit 2140 decodes the RE, which is a muting region, in a manner such as not considering the decoding when decoding the data received from the serving cell, and the muted resource region. The CSI-RS of the neighbor cell received from the resource region of the neighbor cells corresponding to the CSI-RS of the previously received serving cell may be decoded to decode the reference signal, and then the channel state may be measured therefrom.

This not only improves the efficiency of decoding the CSI-RS, but also accurately decodes the CSI-RS of each cell by eliminating interference with the CSI-RS of adjacent cells, thereby enabling accurate channel estimation. .

In addition, in the muting information configuration according to the present embodiment or the channel state acquisition technique using the same, various methods or techniques described with reference to FIGS. 2 to 16 may be used, and detailed descriptions thereof will be omitted in order to avoid duplication of description.

Using the above embodiments, the CSI-RS pattern of adjacent cells forming a multi-cell such as a CoMP set, the number of CSI-RS antenna ports of each adjacent cell, a muting period in time / frequency, or taking into account cycles, offsets, and the like, signaling information about a part to be muted in a resource space of a CSI-RS signal transmitted from a base station to each UE according to each situation, that is, By constructing and transmitting the muting information, there is an effect that it is possible to provide concise methods that are efficient and can reduce overhead as much as possible.

In addition, in the multi-cell environment, the serving cell generates and transmits a CSI-RS muting the region overlapping with the CSI-RS of the adjacent cell, thereby enabling accurate CSI-RS decoding, thereby accurately performing channel state estimation. It can be effective.

In the above description, all elements constituting the embodiments of the present invention are described as being combined or operating in combination, but the present invention is not necessarily limited to the embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented in one independent hardware, each or all of the components may be selectively combined to perform some or all functions combined in one or a plurality of hardware. It may be implemented as a computer program having a. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program may be stored in a computer readable storage medium and read and executed by a computer, thereby implementing embodiments 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 "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

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

Claims (21)

In a multi-cell environment, a specific cell transmits muting information in consideration of CSI-RS interference of an adjacent cell.
Receive CSI-RS information of a neighbor cell including at least one of a CSI-RS pattern, the number of CSI-RS antenna ports, a CSI-RS transmission duty cycle, and CSI-RS transmission subframe offset information from the neighbor cell. Making;
Determining a muting region, which is a time / frequency region where the muting is necessary by overlapping with the CSI-RS of the neighboring cell based on the CSI-RS information of the neighboring cell;
A first data field indicating a muting period and a muting offset of a muting subframe included in the muting region, and a second data field indicating one or more of a muting pattern group in the muting subframe and a specific muting pattern in the muting pattern group. Generating muting information comprising; And
CSI-RS muting information transmission method comprising the step of transmitting the generated muting information to the terminal. The method of claim 1,
Generating the muting information,
Generating a first data field indicating a muting duty cycle and a muting offset of a muting subframe to which muting is applied;
Generating a second data field representing at least one of a muting pattern group in the muting subframe and a specific muting pattern corresponding to a resource region to which substantial muting is applied; CSI-RS muting How to send information. The method of claim 2,
In the first step,
CSI-RS muting information transmission method is determined according to the relationship between the position of the muting sub-frame to which the muting is applied, the CSI-RS transmission period and the CSI-RS transmission offset of the specific cell or neighbor cell . The method of claim 3,
If the muting period and the muting offset is the same for both the neighboring cell and the CSI-RS transmission period and the CSI-RS transmission offset of the serving cell,
CSI-RS muting information transmission method, characterized in that the first data field is composed of 0 bits. The method of claim 3,
If the muting offset is the same as the CSI-RS transmission offset of the serving cell for all of the adjacent cells and the muting period is a multiple of the CSI-RS transmission period of the serving cell,
The first data field is 2 bits, 4 bits, 8 bits,... , 2 ^M bits (M is a natural number, where 2 ^M is determined to be equal to or greater than the maximum multiple of the muting period for the CSI-RS transmission period), each bit being one of the serving cells. CSI-RS muting information transmission method, characterized in that corresponding to the CSI-RS transmission period. The method of claim 5,
The first data field to indicate the number of information bits configured

CSI-RS muting information transmission method characterized in that it further comprises a bit. The method of claim 3,
If the muting offset is the same as the CSI-RS transmission offset of the serving cell for all of the adjacent cells and the muting period is a multiple of the CSI-RS transmission period of the serving cell,
The first data field is

And a bit (M is a natural number, and ^2M is determined to be equal to or greater than a maximum multiple of the muting period for the CSI-RS transmission period). The method of claim 3,
If the muting offset is the same as the CSI-RS transmission offset of the serving cell for all the neighboring cells, but the muting period for each neighboring cell may be different from the CSI-RS transmission period of the serving cell,
The first data field is a CSI-RS muting information transmission method comprising a 2-bit or 3-bit value determined according to the number of types of muting periods for each adjacent cell to be muted. The method of claim 3,
If the muting offset is the same as the CSI-RS transmission offset of the serving cell for all the neighboring cells, but the muting period for each neighboring cell may be different from the CSI-RS transmission period of the serving cell,
The first data field includes 2 bits, 4 bits, 8 bits, ... for each adjacent cell to be muted. And 2 ^M bits (M is a natural number). The method of claim 3,
If the muting period is the same as the CSI-RS transmission period of the serving cell for all the neighboring cells, but the muting offset for each neighboring cell may be different from the CSI-RS transmission offset of the serving cell,
The first data field is a CSI-RS muting information transmission method, characterized in that for each adjacent cell to be muted, a value of one of 2 bits to 4 bits determined according to the size of the muting period. The method of claim 3,
If the muting period and the muting offset for each of the adjacent cells may be different from the CSI-RS transmission period and the CSI-RS transmission offset of the serving cell,
The first data field is for each adjacent cell to be muted.

The CSI-RS muting information transmission method comprising a bit (M is a natural number) value. The method of claim 2,
In the second step, the CSI-RS muting information transmission method comprising configuring a second data field to directly display information on a specific muting pattern without information on the muting pattern group. The method of claim 12,
The second data field is a CSI-RS muting information transmission method comprising a 5- or 6-bit value for each of the possible muting patterns for each adjacent cell to be muted. The method of claim 12,
The second data field has 5 bits for each of the muting patterns except for the pattern including the CSI-RS pattern of the serving cell or the pattern included in the CSI-RS pattern of the serving cell, for each adjacent cell to be muted. CSI-RS muting information transmission method comprising a value. The method of claim 12,
The second data field indicates whether to apply muting in a bitmap format to each of resource element pairs (RE-pairs) corresponding to each of the CSI-RS patterns when transmitted to two antenna ports. CSI-RS muting information transmission method comprising a bit value of one of 12 bits to 28 bits. The method of claim 2,
In the second step, the second data field is configured to represent only the muting pattern group, and all resource regions belonging to the muting pattern group are muted. The method of claim 16,
One bit of 3 to 7 bits indicating whether or not muting is applied to each of the muting pattern groups corresponding to each of the CSI-RS patterns when the second data field is transmitted to 8 antenna ports in bitmap format. CSI-RS muting information transmission method comprising a value. The method of claim 1,
In the muting information transmission step, the muting information transmission method through the upper end signaling (RRC) of the L3 layer, or CSI-RS muting information transmission method characterized in that the dynamic transmission through the PDCCH of the L1 layer (dynamic) . A method for acquiring a channel state of each cell after receiving a CSI-RS from two or more cells, the receiving device comprising:
Muting information including a first data field indicating a muting period and a muting offset of a muting subframe from a serving cell among two or more cells, and a second data field indicating one or more of a muting pattern group and a specific muting pattern in the muting subframe. Receiving;
Receiving a CSI-RS of a neighbor cell transmitted from a resource region of a neighboring cell corresponding to a portion muted by the muting information in a CSI-RS of a serving cell and a resource space for data transmission of the serving cell;
Identifying a muting area in a resource space for data transmission of the serving cell using the muting information and identifying a CSI-RS transmission area of a neighboring cell corresponding thereto;
And decoding the CSI-RSs of the serving cell and the neighbor cell in consideration of the muting region to obtain a channel state. An apparatus for transmitting CSI-RS muting information,
CSI of neighbor cell including one or more of CSI-RS pattern, number of CSI-RS antenna ports, CSI-RS transmission duty cycle, CSI-RS transmission subframe offset information from one or more neighbor cells in a multi-cell environment A neighbor cell information receiver for receiving RS information;
A muting area determiner configured to determine a muting area, which is a time / frequency area that requires muting by overlapping with the CSI-RS of a corresponding cell in a resource space for data transmission of a serving cell based on the CSI-RS information of the neighbor cell;
A first data field indicating the muting area, the muting period and the muting offset of the muting subframe, and a second data field indicating one or more of a muting pattern group in the muting subframe and a specific muting pattern in the muting pattern group Muting information generating unit for generating muting information including a;
CSI-RS muting information transmitting apparatus comprising a muting information transmitting unit for transmitting the generated muting information to the UE. An apparatus for acquiring a channel state of each cell after receiving a CSI-RS from two or more cells, the apparatus comprising:
Muting information including a first data field indicating a muting period and a muting offset of a muting subframe from a serving cell among two or more cells, and a second data field indicating one or more of a muting pattern group and a specific muting pattern in the muting subframe. Muting information receiving unit for receiving;
CSI-RS for receiving a CSI-RS signal of a neighbor cell transmitted from a resource region of a neighboring cell corresponding to a portion muted by the muting information among the CSI-RS of a serving cell and a resource space for data transmission of the serving cell Receiving unit;
A muting area checking unit for checking a muting area in a resource space for data transmission of the serving cell using the muting information and identifying a CSI-RS transmission resource area of a neighboring cell corresponding thereto;
And a channel state obtaining unit for obtaining a channel state by decoding the CSI-RS signals of the serving cell and the adjacent cell in consideration of the muting area.

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