WO2012150788A2 - Method and device for transmitting and receiving reference signals in wireless communication system - Google Patents

Abstract

The present invention relates to a method and device for transmitting and receiving a reference signals in a wireless communication system. When a reference signals for a particular terminal are transmitted, the present invention provides a feature of transmitting reference signal information, which indicates the number of layers allocated to said particular terminal, antenna ports and scrambling IDs for said layers, and the total number of whole layers allocated to said particular terminal or terminals using the same resource area by including the particular terminal. Thus, when a reference signal is decoded in a particular terminal (UE) in MU-MIMO, interference is removed by identifying interference caused by other terminals (UE) whereby the overall performance of a system is improved.

Description

Method and apparatus for transmitting and receiving reference signal in wireless communication system

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for constructing and transmitting a reference signal.

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

Current wireless communication system is a high-speed large-capacity communication system capable of transmitting and receiving various data such as video, wireless data, etc., away from voice-oriented services, and it is required to develop a technology capable of transmitting large-capacity data corresponding to a wired communication network.

However, there is a problem in that a performance degradation of a wireless communication system occurs due to interference caused by other UEs sharing resources in a multiple input multiple output mode. Therefore, there is a need for a request for solving the performance degradation of a wireless communication system.

The present specification provides an apparatus and method for configuring a reference signal in a wireless communication system.

The present specification provides an apparatus and method for transmitting and receiving a reference signal in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for transmitting and receiving configuration information for configuring a reference signal in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for extracting a reference signal and configuration information of the reference signal in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for transmitting and receiving reference signals and reference signal configuration information for configuring a reference signal for a specific terminal in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for transmitting and receiving reference signal and reference signal configuration information for another terminal using a resource region such as a specific terminal in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for transmitting an index having a variable number of layers, an antenna port number, and a scrambling code in response to a set codeword in a wireless communication system.

In addition, the present specification, by using the index defined for the reference signal in the wireless communication system, receiving the number of extracting the reference signal by checking the number of the variable layer, the antenna port number, and the scrambling code corresponding to the set codeword An apparatus and method are provided.

In addition, the present disclosure provides an apparatus and method for transmitting and receiving a reference signal for removing interference by other UEs sharing resources in a multiple input multiple output mode in a wireless communication system.

In one aspect, the present invention provides a method for transmitting a reference signal of a base station in a wireless communication system, comprising: generating and transmitting a reference signal for a specific terminal; And a number of layers allocated for transmitting a reference signal to the specific terminal, an antenna port number and a scrambling ID for the layer, and a reference signal to terminals using the same resource region, including the specific terminal or the specific terminal. Transmitting reference signal information indicative of the total number of allotted layers in transmission, wherein the antenna port number and the scrambling ID for the allotted layer are predetermined according to the total number of allotted layers. It provides a method characterized in that.

In another aspect, the present invention provides a method for receiving a reference signal of a terminal in a wireless communication system, the number of layers allocated in transmitting a reference signal from a base station to the specific terminal, the antenna port number and scrambling ID for the layer, And receiving reference signal information indicating the total number of all layers allocated for transmitting a reference signal to terminals using the same resource region including the specific terminal or the specific terminal. Receiving a reference signal from the base station; And extracting the reference signal sequence by using the reference signal information, wherein the antenna port number and the scrambling ID for the allocated all layers are predetermined according to the total number of all allocated layers. Provide a method.

 In still another aspect, the present invention provides an apparatus for transmitting a reference signal to a terminal in a wireless communication system, the apparatus comprising: a reference signal sequence generator for generating a reference signal sequence; And a Resource Element (RE) mapper for allocating the generated reference signal sequence to a time-frequency resource region, wherein the reference signal sequence generator and the resource element mapper are based on reference signal information transmitted to the UE. Generating a reference signal sequence and assigning the same to a time-frequency resource region, wherein the reference signal information includes the number of layers allocated for transmitting a reference signal to a specific terminal, an antenna port number and a scrambling ID for the layer, and And indicating the total number of all layers allocated in transmitting a reference signal to a specific terminal or terminals using the same resource region including the specific terminal, and the antenna port number and the scrambling for the allocated all layers. The ID may be predetermined according to the total number of all assigned layers. It provides an apparatus as set.

In still another aspect, the present invention provides an apparatus for receiving a reference signal from a base station in a wireless communication system, the apparatus comprising: a receiving processor receiving a signal; A resource element (RE) demapper for demapping a resource element (RE) of the received signal; And a reference signal sequence extracting unit for extracting a reference signal sequence from the resource element including the reference signal among the de-mapped resource elements, wherein the resource element (RE) demapper and the reference signal sequence extracting unit are received from the base station. A reference signal sequence is extracted from a resource element (RE) to which a reference signal sequence is mapped using one or more pieces of information, and the reference signal information is used to transmit a reference signal to a specific UE and the number of layers allocated to the reference signal. And an antenna port number, a scrambling ID, and a total number of all layers allocated for transmitting a reference signal to terminals using the same resource region including the specific terminal or the specific terminal. The antenna port number and the scrambling ID for the entire layer are An apparatus is provided which is predetermined according to the total number of sieve layers.

1 is a system configuration diagram of a wireless communication system to which the present invention is applied.

2 is a diagram illustrating the format of control information according to an embodiment of the present invention.

3 is a block diagram of a transmitter according to an embodiment of the present invention.

4 shows a resource element (k, l) used for DM-RS for a normal CP for antenna ports 7 to 14 to which the present invention is applied.

FIG. 5 shows a resource element (k, l) used for DM-RS for extended CP for antenna ports 7 and 8 to which the present invention is applied.

6 is a block diagram of a receiving apparatus according to an embodiment of the present invention.

7 is a signal flowchart for transmitting a reference signal according to an embodiment of the present invention.

8 is a signal flowchart for receiving a reference signal according to an embodiment of the present invention.

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 addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a system configuration diagram of a wireless communication system to which the present invention is applied.

Wireless communication system 100 according to an embodiment for providing various communication services such as voice, packet data, etc. is eNodeB 110 and two or more UEs (120-1, ..., 120-n, n is a natural number of two or more) It includes.

UEs 120-1,..., 120-n in the present specification are generic concepts meaning user terminals in wireless communication, and of course, user equipment (UE) in WCDMA and Long Term Evolution (LTE), HSPA, and the like. It should be interpreted as a concept that includes a mobile station (MS), a user terminal (UT), a subscriber station (SS), and a wireless device in GSM.

The eNodeB 110 or cell generally refers to any device or function or specific area that communicates with the UEs 120-1,..., 120-n and includes a Node-B, a sector ( Other terms may be referred to as a sector, a site, a base transceiver system (BTS), an access point, a relay node, and the like.

That is, in the present specification, the eNodeB 110 or a cell is a part covered by a base station controller (BSC) in CDMA, a NodeB in WCDMA, an eNodeB (or a site) or a sector in LTE. It should be interpreted as a comprehensive meaning of an area or function, and encompasses various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node communication range.

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 This 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.

The wireless communication system 100 to which 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. For example, downlink uses Orthogonal Frequency Division Multiple Access (OFDMA), and uplink uses a single carrier-frequency division multiple (SC-FDMA). Access can be used.

In the LTE communication system, in case of downlink, a cell-specific reference signal (CRS), a MBSFN reference signal (Multicast / Broadcast over Single Frequency Network Reference Signal (MBSFN-RS), a UE-specific reference signal (UE) Reference signals (or reference signals, RS) such as -specific reference signals are defined. The UE-specific reference signal is also called a demodulation reference signal (DM-RS) according to its purpose.

In the present specification, a layer refers to a data layer that is mapped to each antenna port in an eNodeB or a UE and can be transmitted simultaneously logically. However, data transmitted through each layer may be the same or different. Therefore, the number of layers may be equal to or smaller than the number of antenna ports.

On the other hand, the antenna port (antenna port) is used to represent the time-frequency resource region that is divided into each spatial (spatial). Therefore, when the antenna port number is different in the antenna port used for the same purpose, this means a time-frequency resource region that is spatially distinguished as different antennas.

For example, CRS with up to 4 antennas has an antenna port number of 0 to 3, and MBSFN-RS and LTE Rel-8 UE-specific RS (for example, Demodulation Reference DM-RS) using up to 1 antenna each. In the case of Signal (PRS) and Positioning Reference Signal (PRS), the antenna port numbers are 4, 5, and 6. Also, the antenna port numbers of LTE Rel-9 / 10 DM-RS using up to 8 antennas are 7 to 14. In the case of CSI-RS, the maximum number of antennas is 8, so the antenna port number is 15 to 22. In this case, if the antenna port number is different within each specific RS, the antenna port numbers are spatially distinguished from each other. This means that the antennas have a time-frequency resource region.

The wireless communication system 100 according to an embodiment is a multiple input multiple output (MIMO) wireless communication system. There are two types of multi-input multi-output wireless communication systems: single-user MIMO (SU-MIMO) and multi-user MIMO (MU-MIMO).

The eNodeB 110 sends specific related downlink control signals 130-1,..., 130-n to the UEs 120-1,..., 120-n to support transmission of downlink and uplink transport channels. send. The downlink control signals 130-1, ..., 130-n are reference signals and data 140-1, ..., 140- that the eNodeB 110 transmits to the UEs 120-1, ..., 120-n. n) downlink scheduling assignment information including information necessary for receiving and demodulating / decoding, and uplink scheduling grant information indicating resources and transmission formats used by the UE for uplink transmission; And HARQ ACK / NACK information for uplink transmission.

The physical downlink control channel (PDCCH) carries downlink control signals 130-1, ..., 130-n. This physical downlink control channel (PDCCH) is transmitted in an aggregation of one or more consecutive control channel elements (CCEs). The PDCCH carrying control information 130-1,..., 130-n supports various PDCCH formats as shown in Table 1 below.

Table 1

The downlink control information 130-1,..., 130-n are classified into downlink control information (DCI) formats having a defined format. These DCI formats are classified according to specific message size and purpose.

2 is a format configuration diagram of downlink control information (DCI) according to an embodiment of the present invention. In this case, although the format of the DCI format is exemplarily illustrated in FIG. 2, it may be a format of any DCI formats present or future.

Referring to FIG. 2, the DCI format 200 may include a Carrier Indicator Field (CIF) 210, resource allocation information 220, and reference signal information 230.

A Carrier Indicator Field (CIF) may be 0 or 3 bits. The component carrier identifier 210 may indicate a component carrier including a PDCCH carrying control information of a DCI format in a carrier aggregation environment in which a plurality of component carriers (CC) of up to 20 MHz may be bundled and used. Can be.

Each of the M downlink CCs (M is one or more natural numbers) includes a physical downlink shared channel (PDSCH). Meanwhile, each downlink component carrier (CC) may or may not include a physical downlink control channel (PDCCH). That is, a control channel may be included in all downlink component carriers (CCs) among all the downlink component carriers (CCs), and a control channel may be included only in some downlink component carriers (CCs).

As such, an element carrier identifier (CIF) 210, which is CC identification information when one PDCCH is scheduling one or more CCs, may indicate two or more CCs.

The resource allocation information 220 may include downlink scheduling allocation information or uplink scheduling grant information.

The reference signal information 230 may include reference signal configuration information such as an antenna port (s) number, a scrambling identity, a number of layers, and the like.

The reference signal is a cell-specific reference signal (CRS) for identifying channel information in downlink and a UE for demodulating a physical channel, for example, a physical downlink shared channel (PDSCH). It may be one of a UE-Specific Reference Signal (DM-RS) and a Channel State Information Reference Signal (CSI-RS) for estimating channel state information. Hereinafter, the reference signal will be described using DM-RS as an example, but the present disclosure is not limited thereto.

The reference signal information 230 includes a number of layers assigned to transmit a reference signal to a specific UE, an antenna port (s) number for the layer (s), and a scrambling ID. Along with the reference signal configuration information, the total number of layers allocated for transmitting the reference signal to the UE and other UE (s) connected to the corresponding UE and MU-MIMO and using the same resource region is added. It can be included as.

For example, the reference signal information 230 transmitted by the eNodeB to a specific UE is the number of layers allocated to transmit the reference signal to the specific UE and the antenna port (s) of the layer (s). And a total number of layers allocated for transmitting the reference signal to the UE and other UE (s) using the same resource region by being connected to the UE and MU-MIMO together with the reference signal configuration information including the scrambling ID. of layers). Here the total number of layers is added in the embodiment of the present invention to improve the MU-MIMO operation.

At this time, the number of layers allocated to transmit a reference signal to the specific UE, the antenna port (Antenna port (s)) number and scrambling ID for the layer (s), and the eNodeB are connected to the corresponding UE and MU-MIMO. Representing the reference signal information 230 in the control information 220 as an index or indicator indicating the total number of layers allocated for transmitting the reference signal to other UE (s) using the resource region. The method can vary.

For example, in SU-MIMO or MU-MIMO, the total number of layers allocated for transmitting a reference signal to the UE and other UE (s) connected to the UE and MU-MIMO using the same resource zone. ) And all possible cases for the configurable number of layer (s) allocated for transmitting a reference signal to the specific UE may be shown in Table 2.

In (x, y) of Table 2, x means antenna port number and y means scrambling ID. In Table 2, the scrambling ID may be 0 or 1 for the antenna ports 7 and 8, and the scrambling ID may be 0 for the antenna ports 9 to 14.

TABLE 2

Total number of layers (number of UEs)	All possible cases	Pre-defined case
1 layer, SU-MIMO (1UE; 1layer)	4 cases-(7,0) / (7,1) / (8,0) / (8,1)	(7,0)
2 layers, SU-MIMO (1UE; 2layers)	2 cases-(7-8,0) / (7-8,1)	(7-8,0)
2 layers, MU-MIMO (2UEs; (1 + 1) layers)	6 cases-(7,0) + (7,1) / (7,0) + (8,0) / (7,0) + (8,1) / (7,1) + (8,0) / (7,1) + (8,1) / (8,0) + (8,1)	(7,0) + (8,0)
3 layers, SU-MIMO (1UE; 3layers)	1 case-(7 ~ 9,0)	(7-9,0)
3 layers, MU-MIMO (2UEs; (2 + 1) layers)	4 cases-(7-8,0) + (7,1) / (7-8,0) + (8,1) / (7-8,1) + (7,0) / (7-8, 1) + (8,0)	(7-8,0) + (7,1)
3 layers, MU-MIMO (3UEs; (1 + 1 + 1) layers)	4 cases-(7,0) + (7,1) + (8,0) / (7,0) + (7,1) + (8,1) / (7,0) + (8,0) + (8,1) / (7,1) + (8,0) + (8,1)	(7,0) + (7,1) + (8,0)
4 layers, SU-MIMO (1UE; 4layers)	1 case-(7 ~ 10,0)	(7-10,0)
4 layers, MU-MIMO (2UEs; (2 + 2) layers)	1 case-(7 ~ 8,0) + (7 ~ 8,1)	(7-8,0) + (7-8,1)
4 layers, MU-MIMO (3UEs; (2 + 1 + 1) layers)	2 cases-(7 ~ 8,0) + (7,1) + (8,1) / (7 ~ 8,1) + (7,0) + (8,0)	(7 ~ 8,0) + (7,1) + (8,1)
4 layers, MU-MIMO (4UEs; (1 + 1 + 1 + 1) layers)	1 case-(7,0) + (7,1) + (8,0) + (8,1)	(7,0) + (7,1) + (8,0) + (8,1)
5 layers, SU-MIMO (1UE; 5layers)	1 case-(7 ~ 11,0)	(7 ~ 11,0)
6 layers, SU-MIMO (1UE; 6layers)	1 case-(7 ~ 12,0)	(7-12,0)
7 layers, SU-MIMO (1UE; 7layers)	1 case-(7 ~ 13,0)	(7-13,0)
8 layers, SU-MIMO (1UE; 8layers)	1 case-(7 ~ 14,0)	(7-14,0)

In this case, the eNodeB is connected to the UE and MU-MIMO for MU-MIMO, and the maximum number of layers allocated to transmit a reference signal to other UE (s) using the same resource region is 4, and the specific UE is referred to. Limit the maximum number of layers per UE allocated for transmitting signals to 2 and for each layer, set the antenna port number and the pair of scrambling IDs, namely (antenna port number, scrambling ID) in a specific order, e.g. (antenna Port number, scrambling ID) = (7,0) → (8,0) → (7,1) → (8,1) (pre-defined case), the eNodeB sends the UE and MU-MIMO Configurable or applicable to the total number of layers allocated for transmitting a reference signal to other UE (s) connected and using the same resource region and the number of layers allocated for transmitting a reference signal to a specific UE. All possible cases are shown in Table 3. Can. In Table 3, the same as Table 2, the scrambling ID may be 0 or 1 for the antenna ports 7 and 8, and the scrambling ID may be 0 for the antenna ports 9 to 14.

TABLE 3

The maximum number of layers allocated for transmitting a reference signal to the UE and other UE (s) connected to the UE and the MU-MIMO using the same resource region is 4, and is allocated for transmitting the reference signal to the specific UE. Limit the maximum number of layers per UE to 2 and pair the antenna port number and the scrambling ID in order for each layer (antenna port number, scrambling ID) = (7,0) → (8,0) → (7 , 1) → As previously determined by (8,1), all possible cases of configurable or applicable in Table 3 are configured with some of all possible cases of Table 2 excluded.

For example, in Table 3, the total number of layers allocated for transmitting the reference signal to the UE and other UE (s) using the same resource region by connecting to the UE and MU-MIMO is 1, and the reference signal is transmitted to the specific UE. When the number of layers allocated for transmission is 1 (SU-MIMO) All four possible cases in Table 2 ((7,0) / (7,1) / (8,0) / (8,1)) The remaining three cases other than (7,0) are excluded ((7,1) / (8,0) / (8,1)).

Similarly, the total number of layers allocated for transmitting a reference signal to the UE and other UE (s) using the same resource region by connecting with the UE and MU-MIMO is 2, and the eNodeB is connected with MU-MIMO to access the same resource region. If the reference signal is transmitted to the corresponding UE and one other UE (the total number of UEs connected by MU-MIMO = 2), all possible cases are six ((7,0) as shown in Table 2. + (7,1) / (7,0) + (8,0) / (7,0) + (8,1) / (7,1) + (8,0) / (7,1) + ( 8,1) / (8,0) + (8,1)), but as shown in Table 3, one possible case is (7,0) + (8,0). Because for each layer, the pairs of antenna port number and scrambling ID are specified in a specific order, i.e. (antenna port number, scrambling) = (7,0) → (8,0) → (7,1) → (8,1) Of the six cases mentioned in Table 2, in addition to (7,0) + (8,0), the remaining five cases ((7,0) + (7,1) / (7,0) This is because) + (8,1) / (7,1) + (8,0) / (7,1) + (8,1) / (8,0) + (8,1)) are excluded.

In summary, the maximum number of layers allocated to transmit a reference signal to the UE and the MU-MIMO connected to the other UE (s) using the same resource region is 4, and the reference signal is transmitted to the specific UE. Limit the maximum number of layers per UE allocated to 2 to 2, and set the antenna port number and the scrambling ID pair for each layer (antenna port number, scrambling ID) = (7,0) → (8,0) → ( 7,1) → (8,1), there are 13 possible cases that can be configured or applied for one codeword in Table 3, and configurable or applied for two codewords. There are a total of 10 possible cases you can do. As described above, the scrambling ID is 0 or 1 for antenna ports 7 and 8 and the scrambling ID is 0 for antenna ports 9 to 14.

Therefore, the number of layers allocated to transmit a reference signal to a specific UE for one codeword and two codewords, the antenna port number and the scrambling ID for the layer (s), and the eNodeB determines the corresponding UE and MU-MIMO. For all possible cases that are configurable or applicable to the total number of layers allocated to transmit a reference signal to other UE (s) using the same resource region connected to a network, indicating these cases A table of indices or indicators might look like Table 4. In Table 4, the table on the left is for using one codeword (CW), and the table on the right is for using two codewords (CW).

Table 4

One codeword: Codeword 0 enabled, Codeword 1 disabled		Two codewords: Codeword 0 enabled, Codeword 1 enabled
Value	Message	Value	Message
0	1 layer, port 7, n SCID = 0, L total = 1	0	2 layers, ports 7 ~ 8, n SCID = 0, L total = 2
One	1 layer, port 7, n SCID = 0, L total = 2	One	2 layers, ports 7 ~ 8, n SCID = 0, L total = 3
2	1 layer, port 8, n SCID = 0, L total = 2	2	2 layers, ports 7 ~ 8, n SCID = 0, L total = 4
3	1 layer, port 7, n SCID = 0, L total = 3	3	2 layers, ports 7 ~ 8, n SCID = 1, L total = 4
4	1 layer, port 7, n SCID = 1, L total = 3	4	3 layers, ports 7-9
5	1 layer, port 8, n SCID = 0, L total = 3	5	4 layers, ports 7 ~ 10
6	1 layer, port 7, n SCID = 0, L total = 4	6	5 layers, ports 7 ~ 11
7	1 layer, port 7, n SCID = 1, L total = 4	7	6 layers, ports 7 ~ 12
8	1 layer, port 8, n SCID = 0, L total = 4	8	7 layers, ports 7 ~ 13
9	1 layer, port 8, n SCID = 1, L total = 4	9	8 layers, ports 7 ~ 14
10	2 layers, ports 7 ~ 8	10	Reserved
11	3 layers, ports 7-9	11	Reserved
12	4 layers, ports 7 ~ 10	12	Reserved
13	Reserved	13	Reserved
14	Reserved	14	Reserved
15	Reserved	15	Reserved

As shown in Table 4, the reference signal information 230 includes the number of layers allocated for transmitting the reference signal to the specific UE, the antenna port number and the scrambling ID for the layer (s), and the eNodeB to the corresponding UE and MU-MIMO. The control information 200 is included in an index indicating the total number of layers allocated for transmitting a reference signal to other UE (s) connected to and using the same resource region. In Table 4, the number of layers allocated to transmit a reference signal to the specific UE, the antenna port number and the scrambling ID for the layer (s), and the eNodeB are connected to the corresponding UE and MU-MIMO to use the same resource region. The number of branches of all possible cases that are configurable or applicable to the total number of layers allocated for transmitting a reference signal to other UE (s) is a total of 13 for one codeword and a total for two codewords. 10.

Therefore, when the reference signal information 230 is configured with a total of 16 indexes including reserved indexes that are not used as shown in Table 4 to represent a maximum of 13 indexes, the reference signal information 230 ) Can be represented using 4 bits.

In addition, as shown in Table 4 or Table 5 below, the order of each index value expressed in total of 13 for one codeword and 10 for two codewords may be reversed. For example, the positions of index "4" and index "5" can be interchanged. However, even if the order of the indexes is reversed, the total number of branches (13 for one codeword and 10 for two codewords) for each codeword will be the same.

For example, if the reference signal information 230 includes the index “5” for one codeword, the UE that has received the reference signal information 230 has a total number of layers of 3 and the number of layers allocated to it. It can be seen that 1, the antenna port number for the layer is 8, and the scrambling ID n _scid is 0.

As such, the reference signal information 230 transmitted by the eNodeB 110 to a specific UE is not only the reference signal configuration information of the specific UE, but also the eNodeB 110 is connected to the specific UE and MU-MIMO to use the same resource region. Since the total number of layers allocated for transmitting the reference signal to the other UE (s), the specific UE, for example, the UE 120-1 receiving the control information of the DCI format shown in FIG. The total number of layers of the information 230 and the number of layers of the information 230 may be compared to determine whether the layer is in the SU-MIMO mode or the MU-MIMO mode. In addition, when the UE 120-1 is in the MU-MIMO mode, the UE 120-1 may be connected to the MU-MIMO to know the total number of layers of other UE (s) using the same resource region, the associated antenna port number, and the scrambling ID. .

In more detail, the total number of layers allocated by the eNodeB 110 for transmitting a reference signal in a specific resource region is greater than the number of layers allocated for transmitting the reference signal to a specific UE. In this case, the UE 120-1 may know whether the MU-MIMO mode is present. In addition, the eNodeB is connected to the corresponding UE and MU-MIMO to transmit the reference signal to the specific UE with a maximum number of four layers allocated to transmit the reference signal to other UE (s) using the same resource region. Limit the maximum number of layers per UE to 2 and assign pairs of antenna port numbers and scrambling IDs for each layer in that order: (antenna port number, scrambling ID) = (7,0)-> (8,0 As previously determined as)-> (7,1)-> (8,1), the UE 120-1 transmits a reference signal to other UE (s) connected with MU-MIMO and using the same resource region. It is possible to know the antenna port number and the scrambling ID for the layers allocated in order to accurately know the interference on the UE 120-1 through this.

As shown in Table 5, one UE 120-1 receiving the control information of the DCI format shown in FIG. 2 knows not only its own reference signal configuration information but also other UE (s) reference signal configuration information. I can arrange it. In Table 5, L _total is a layer allocated by the eNodeB 110 in SU-MIMO or MU-MIMO to transmit a reference signal to the specific UE and other UE (s) connected to the MU-MIMO and using the same resource region. N _UE means the total number of _UEs connected to the specific UE and MU-MIMO in SU-MIMO or MU-MIMO and uses the same resource area. AP means antenna port and SCID means scrambling ID. Means.

Table 5

value		Message	Implicit information
			L total	N UE	AP and SCID of other layers
OneCodeword	0	1 layer, port 7, n SCID = 0, L total = 1	One	One	N / A
	One	1 layer, port 7, n SCID = 0, L total = 2	2	2	Total 1 other layer; -port 8, n SCID = 0 (from UE X)
	2	1 layer, port 8, n SCID = 0, L total = 2	2	2	Total 1 other layer; port 7, n SCID = 0 (from UE X)
	3	1 layer, port 7, n SCID = 0, L total = 3	3	3	Total 2 other layers; -port 7, n SCID = 1 (from UE X) -port 8, n SCID = 0 (from UE Y)
	4	1 layer, port 7, n SCID = 1, L total = 3	3	2 or 3	Total 2 other layers; ports 7-8, n SCID = 0 (from UE X or UE X + Y)
	5	1 layer, port 8, n SCID = 0, L total = 3	3	3	Total 2 other layers; - port 7, n SCID = 0 (from UE X) - port 7, n SCID = 1 (from UE Y)
	6	1 layer, port 7, n SCID = 0, L total = 4	4	4	Total 3 other layers; -port 7, n SCID = 1 (from UE X) -port 8, n SCID = 0 (from UE Y) -port 8, n SCID = 1 (from UE Z)
	7	1 layer, port 7, n SCID = 1, L total = 4	4	3 or 4	Total 3 other layers;-ports 7 ~ 8, n SCID = 0 / port 8, n SCID = 1 (from UE X + Y or UE X + Y + Z)
	8	1 layer, port 8, n SCID = 0, L total = 4	4	4	Total 3 other layers; port 7, n SCID = 0 (from UE X) -port 7, n SCID = 1 (from UE Y) -port 8, n SCID = 1 (from UE Z)
	9	1 layer, port 8, n SCID = 1, L total = 4	4	3 or 4	Total 3 other layers; ports 7-8, n SCID = 0 / port 7, n SCID = 1 (from UE X + Y or UE X + Y + Z)
	10	2 layers, ports 7 ~ 8	2	One	N / A
	11	3 layers, ports 7-9	3	One	N / A
	12	4 layers, ports 7 ~ 10	4	One	N / A
Twocodeword	0	2 layers, ports 7 ~ 8, n SCID = 0, L total = 2	2	One	N / A
	One	2 layers, ports 7 ~ 8, n SCID = 0, L total = 3	3	2	Total 1 other layer; port 7, n SCID = 1 (from UE X)
	2	2 layers, ports 7 ~ 8, n SCID = 0, L total = 4	4	2 or 3	Total 2 other layers;-ports 7 ~ 8, n SCID = 1 (from UE X or UE X + Y)
	3	2 layers, ports 7 ~ 8, n SCID = 1, L total = 4	4	2	Total 2 other layers;-ports 7-8, n SCID = 0 (from UE X)
	4	3 layers, ports 7-9	3	One	N / A
	5	4 layers, ports 7 ~ 10	4	One	N / A
	6	5 layers, ports 7 ~ 11	5	One	N / A
	7	6 layers, ports 7 ~ 12	6	One	N / A
	8	7 layers, ports 7 ~ 13	7	One	N / A
	9	8 layers, ports 7 ~ 14	8	One	N / A

For example, in the above-described example in which the reference signal information 230 includes the index "5" for one codeword, the UE that has received the reference signal information 230 has its own reference signal configuration information and MU-MIMO mode. In addition, the total number of layers allocated to other UEs (UE X, Y, or Z in Table 5) connected to the MU-MIMO with the corresponding UE and transmitting the reference signal using the same resource region It can be seen that 2.

Also, for the layer, the pair of antenna port number and scrambling ID (antenna port number, scrambling ID) is (antenna port number, scrambling ID) = (7,0) → (8,0) → (7,1) → (8 The number of other UEs is 2 and the pair of the antenna port number and the scrambling ID of the two UEs is (7,0), and the other antenna port number of the other UEs is It can be seen that the pair of scrambling IDs is (7,1). Because the number of layers allocated by the eNodeB 110 to transmit the reference signal to the UE that has received the RS information 230 is 1, and the antenna port number and the scrambling ID pair for this layer are (8,0). Since the total number of layers allocated to transmit a reference signal to the specific UE and other UE (s) connected to the MU-MIMO and using the same resource area is 3, the eNodeB 110 is connected to the MU-MIMO and is connected to the same UE. The total number of layers allocated for transmitting the reference signal to other UEs using the resource region is 2, where the pairs of antenna port number and scrambling ID are (7,0) and (7,1) according to a predetermined rule. It can be seen that. In other words, if you use (antenna port number, scrambling ID) = (7,0) → (8,0) → (7,1) → (8,1), each layer is assigned The antenna port number and the scrambling ID pair used for the (7,0), (7,1), (8,0) are the antenna port number and the scrambling ID pair used for the layer assigned to the specific UE. Since it is (8,0), it can be seen that the pairs of the antenna port number and the scrambling ID used for the layer assigned to the other UE (s) are automatically (7,0) and (7,1).

On the other hand, when analyzing the reference signal configuration information of another UE connected to MU-MIMO and using the same resource region, the index included in the reference signal information 230 is shown in Table 4 or Table 5 for one codeword. In the case of 4 ”,“ 7 ”, or“ 9 ”and“ 2 ”for two codewords, the number of other UEs connected with MU-MIMO and using the same resource region and the cases of the reference signal configuration information You can see that there are two numbers each.

For example, if the index included in the reference signal information 230 for one codeword is “4”, the number of layers allocated to transmit the reference signal to the specific UE is 1 and the antenna port number for the layer is 1. Is 7 and the scrambling ID is 1. In addition, since the total number of layers allocated for transmitting a reference signal to the UE and other UE (s) using the same resource region by being connected to the corresponding UE and MU-MIMO is 3, the same node is used by being connected to MU-MIMO. It can be seen that the total number of layers of other UE (s) is 2 and the pairs of antenna port number and scrambling ID of other UE (s) are (7,0) and (8,0) according to a predetermined rule. Therefore, the pairs (7,0) and (8,0) of the antenna port number and the scrambling ID may have two cases in which two layers are allocated to one UE or one layer is allocated to each of the two UEs. have.

The reference signal information 230 includes reference signal configuration information including the number of layers allocated to transmit a reference signal to a specific UE, an antenna port number, and a scrambling ID for the layer as shown in Table 6, and the eNodeB includes the corresponding UE and In the SU-MIMO or MU-MIMO, the eNodeB uses the same resource region as well as the total number of layers allocated for transmitting the reference signal to other UE (s) connected to the MU-MIMO and using the same resource region. It may also include the total number of UE (s) allocated for transmission.

Table 6

One Codeword: Codeword 0 enabled, Codeword 1 disabled		Two Codewords: Codeword 0 enabled, Codeword 1 enabled
Value	Message	Value	Message
0	1 layer, port 7, n SCID = 0, L total = 1, N UE = 1	0	2 layers, ports 7 ~ 8, n SCID = 0, L total = 2, N UE = 1
One	1 layer, port 7, n SCID = 0, L total = 2, N UE = 2	One	2 layers, ports 7 ~ 8, n SCID = 0, L total = 3, N UE = 2
2	1 layer, port 8, n SCID = 0, L total = 2, N UE = 2	2	2 layers, ports 7 ~ 8, n SCID = 0, L total = 4, N UE = 2
3	1 layer, port 7, n SCID = 0, L total = 3, N UE = 3	3	2 layers, ports 7 ~ 8, n SCID = 0, L total = 4, N UE = 3
4	1 layer, port 7, n SCID = 1, L total = 3, N UE = 2	4	2 layers, ports 7 ~ 8, n SCID = 1, L total = 4, N UE = 2
5	1 layer, port 7, n SCID = 1, L total = 3, N UE = 3	5	3 layers, ports 7-9
6	1 layer, port 8, n SCID = 0, L total = 3, N UE = 3	6	4 layers, ports 7 ~ 10
7	1 layer, port 7, n SCID = 0, L total = 4, N UE = 4	7	5 layers, ports 7 ~ 11
8	1 layer, port 7, n SCID = 1, L total = 4, N UE = 3	8	6 layers, ports 7 ~ 12
9	1 layer, port 7, n SCID = 1, L total = 4, N UE = 4	9	7 layers, ports 7 ~ 13
10	1 layer, port 8, n SCID = 0, L total = 4, N UE = 4	10	8 layers, ports 7 ~ 14
11	1 layer, port 8, n SCID = 1, L total = 4, N UE = 3	11	Reserved
12	1 layer, port 8, n SCID = 1, L total = 4, N UE = 4	12	Reserved
13	2 layers, ports 7 ~ 8	13	Reserved
14	3 layers, ports 7-9	14	Reserved
15	4 layers, ports 7 ~ 10	15	Reserved

Since the reference signal information 230 is configured as shown in Table 6, the UE having received the reference signal information 230 as well as the reference signal configuration information of the other UE when there is another UE using the same resource region as shown in Table 7 In the SU-MIMO or MU-MIMO, the total number of UE (s) allocated by the eNodeB to transmit a reference signal using the same resource region can be known. In Table 7, the upper table is for the case of using one codeword (CW), and the lower table is for the case of using two codewords (CW). In Table 7, as in Table 5, L _total indicates that the eNodeB 110 is connected to the specific UE and MU-MIMO in SU-MIMO or MU-MIMO to transmit a reference signal to other UE (s) using the same resource area. N _UE means the total number of UE (s) using the same resource area in SU-MIMO or MU-MIMO, AP means antenna port, and SCID means scrambling ID.

TABLE 7

In addition, as shown in Table 6 or Table 7, the order of each index value represented by a total of 16 for one codeword and 11 for two codewords may be reversed. For example, the positions of index "4" and index "5" can be interchanged. However, although the order of the indexes is reversed, as mentioned in Tables 4 and 5, the total number of branches shown for each codeword in Table 6 or Table 7 (16 for one codeword, two for each codeword). Total 11) and its contents will be the same.

When the reference signal information 230 is configured as shown in Table 2, the reference signal information 230 may be represented using 5 bits, whereas when the reference signal information 230 is configured as shown in Table 4 or Table 6, the reference signal Since the information 230 may be represented using 4 bits, the reference signal information 230 configured as shown in Table 4 or Table 6 may be represented using 4 bits. In addition, when the reference signal information 230 is configured as shown in Table 4 or Table 6, the UE receiving the reference signal information 230 is connected to MU-MIMO as well as its reference signal configuration information to use the same resource region. Reference signal configuration information of other UE (s) or the total number of UE (s) using the same resource region in SU-MIMO or MU-MIMO may also be known.

As such, the reference signal information 230 transmitted by the eNodeB 110 to a specific UE is not only the reference signal configuration information of the specific UE, but also the eNodeB 110 is connected to the specific UE and MU-MIMO to use the same resource region. Since the total number of layers allocated for transmitting the reference signal to the other UE (s), the specific UE, for example, the UE 120-1 receiving the control information of the DCI format shown in FIG. The total number of layers of the information 230 and the number of layers of the information 230 may be compared to determine whether the layer is in the SU-MIMO mode or the MU-MIMO mode. In addition, when the UE 120-1 is in the MU-MIMO mode, the total number of layers of other UE (s) connected to the MU-MIMO and using the same resource region, the associated antenna port number and the scrambling ID, or the SU-MIMO or The total number of other UE (s) using the same resource region in MU-MIMO can also be known.

In more detail, the total number of layers allocated by the eNodeB 110 for transmitting a reference signal in a specific resource region is greater than the number of layers allocated for transmitting the reference signal to a specific UE. In this case, the UE 120-1 may know whether the MU-MIMO mode is present. In addition, UE 120-1 is connected to MU-MIMO and has an antenna port number and scrambling ID or a SU-MIMO or MU- for layers allocated to transmit reference signals to other UE (s) using the same resource region. In the MIMO, the total number of other UEs using the same resource region can be known, and through this, the interference on the UE 120-1 can be accurately known.

Meanwhile, in Table 4, when MU-MIMO classifies up to four layers allocated by the eNodeB 110 to transmit a reference signal in a specific resource region, it is divided into two scrambling IDs (0 or 1) for antenna ports 7 and 8. do. At this time, orthogonal cover code (OCC) or orthogonal sequence is used to distinguish antenna ports 7 and 8, so orthogonality is guaranteed, but the scrambling ID uses a quasi-orthogonal sequence. Use does not guarantee perfect orthogonality. Therefore, in order to more perfectly orthogonality, instead of the scrambling ID, as shown in FIGS. 4 and 5, the same pattern among the antenna ports 7 to 14 (DM-RS sequence is mapped according to each antenna port number. {7,8,11,13} or {9,10,12,14}, which is a set of four antenna ports separated by OCCs using resource elements (RE) locations) You can use either.

ENodeB 110 in MU-MIMO using a set of antenna ports {7,8,11,13} or a set of antenna ports {7,8,11,13} below Describes the configuration of reference signal information 230 to distinguish up to four layers allocated for transmitting a reference signal in a specific resource region, but the set {9, 10, 12, 14} of other antenna ports has the same technical meaning. Has

Also, for the current LTE system, the set of antenna ports using the same pattern and separated by OCC is {7,8,11,13} or {9,10,12,14}, but if the DM-RS sequence is later In order to reduce the overhead of a Resource Element (RE) to which is mapped, the same pattern is used, and a set of antenna ports separated by OCC is determined as {7,8,9,10} or {11, 12,13,14}, the set of antenna ports {7,8,9,10} or {11,12,13,14} using the eNodeB 110 in MU-MIMO Reference signal information 230 may be configured to distinguish up to four layers allocated for transmitting the reference signal. Any other set of antenna ports that use the same pattern and are classified as OCC may be used for this purpose.

In addition, in the current LTE system, the set of antenna ports using the same pattern and separated by OCC is {7,8,11,13} or {9,10,12,14}. In addition, in the current LTE system, a mapping rule for an antenna port in a layer is mapped to a v + 6th antenna port number in a v th layer in one UE. For example, the first layer maps to antenna port 7 (strictly speaking antenna ports 7 or 8), the second layer to antenna port 8, the third layer to antenna port 9, and the fourth layer to antenna port 10. will be. In this case, when three or four layers are used for one UE, two different antenna port sets (that is, {7,8,11,13} and {9,10,12,14}) are used.

If it is necessary to reduce the overhead of the resource element (RE) to which the DM-RS sequence is mapped in the future, the following three methods can be considered.

1) A set of antenna ports using the same pattern and separated by OCC is selected from {7,8,11,13} and {9,10,12,14} to {7,8,9,10} or {11,12 , 13,14}

2) Change the mapping rule for antenna ports in the layers when the total number of layers is 3 and 4 as follows:

The total number of layers is three: {7,8,9}-> {7,8,11}, i.e. the antenna port number for the third layer is 11 rather than 9

The total number of layers is four: {7,8,9,10}-> {7,8,11,13}, i.e. the antenna port numbers for the third and fourth layers are 11 and not 9 and 10. 13

3) Change the mapping rule for antenna ports in the layers when the total number of layers is 3 and 4 as follows.

3 total layers: {(7,0), (8,0), (9,0)}-> {(7,0), (8,0), (7,1)}, That is, the antenna port number for the third layer uses 7, not 9, and SCID is 1.

4 total layers: {(7,0), (8,0), (9,0), (10,0)}

-> {(7,0), (8,0), (7,1), (8,1)}, i.e. the antenna port numbers for the 3rd and 4th layers are 7 and 8 rather than 9 and 10 SCID is set to 1.

Therefore, in view of the above, the set of antenna ports using the same pattern and separated by OCC may be varied as well as {7,8,11,13} as an example of the present invention. Any set of antenna ports separated by OCC may be used for the present invention.

For example, in Tables 3, 4, and 5, the scrambling ID for all antenna ports is set to 0, and the pair of antenna port number and scrambling ID (7,1) is changed to (11,0) and (8,1). ) Is changed to (13,0) as shown in Table 8, Table 9 and Table 10.

Table 8

Total number of layers	All configurable cases for given total number of layers
	Case	SU- or MU-MIMO	UE (s) in MIMO	Pre-define case
One	Case 1-1	SU-MIMO (1UE)	UE A: 1 layer	(7,0)
2	Case 2-1	SU-MIMO (1UE)	UE A: 2 layers	(7-8,0)
	Case 2-2	MU-MIMO (2UEs)	UE A: 1 layer	(7,0)
			UE B: 1 layer	(8,0)
3	Case 3-1	SU-MIMO (1UE)	UE A: 3 layers	(7-9,0)
	Case 3-2	MU-MIMO (2UEs)	UE A: 2 layers	(7-8,0)
			UE B: 1 layer	(11,0)
	Case 3-3	MU-MIMO (3UEs)	UE A: 1 layer	(7,0)
			UE B: 1 layer	(8,0)
			UE C: 1 layer	(11,0)
4	Case 4-1	SU-MIMO (1UE)	UE A: 4 layers	(7-10,0)
	Case 4-2	MU-MIMO (2UEs)	UE A: 2 layers	(7-8,0)
			UE B: 2 layers	(11 & 13,0)
	Case 4-3	MU-MIMO (3UEs)	UE A: 2 layers	(7-8,0)
			UE B: 1 layer	(11,0)
			UE C: 1 layer	(13,0)
	Case 4-4	MU-MIMO (4UEs)	UE A: 1 layer	(7,0)
			UE B: 1 layer	(8,0)
			UE C: 1 layer	(11,0)
			UE D: 1 layer	(13,0)
5	Case 5-1	SU-MIMO (1UE)	UE A: 5 layers	(7 ~ 11,0)
6	Case 6-1	SU-MIMO (1UE)	UE A: 6 layers	(7-12,0)
7	Case 7-1	SU-MIMO (1UE)	UE A: 7 layers	(7-13,0)
8	Case 8-1	SU-MIMO (1UE)	UE A: 8 layers	(7-14,0)

Table 9

One codeword: Codeword 0 enabled, Codeword 1 disabled		Two codewords: Codeword 0 enabled, Codeword 1 enabled
Value	Message	Value	Message
0	1 layer, port 7, L total = 1	0	2 layers, ports 7 ~ 8, L total = 2
One	1 layer, port 7, L total = 2	One	2 layers, ports 7 ~ 8, L total = 3
2	1 layer, port 8, L total = 2	2	2 layers, ports 7 ~ 8, L total = 4
3	1 layer, port 7, L total = 3	3	2 layers, ports 11 & 13, L total = 4
4	1 layer, port 8, L total = 3	4	3 layers, ports 7-9
5	1 layer, port 11, L total = 3	5	4 layers, ports 7 ~ 10
6	1 layer, port 7, L total = 4	6	5 layers, ports 7 ~ 11
7	1 layer, port 8, L total = 4	7	6 layers, ports 7 ~ 12
8	1 layer, port 11, L total = 4	8	7 layers, ports 7 ~ 13
9	1 layer, port 13, L total = 4	9	8 layers, ports 7 ~ 14
10	2 layers, ports 7 ~ 8	10	Reserved
11	3 layers, ports 7-9	11	Reserved
12	4 layers, ports 7 ~ 10	12	Reserved
13	Reserved	13	Reserved
14	Reserved	14	Reserved
15	Reserved	15	Reserved

Table 10

value		Message	Implicit information
			L total	N UE	AP and SCID of other layers
OneCodeword	0	1 layer, port 7, L total = 1	One	One	N / A
	One	1 layer, port 7, L total = 2	2	2	Total 1 other layer;-port 8 (from UE X)
	2	1 layer, port 8, L total = 2	2	2	Total 1 other layer; port 7 (from UE X)
	3	1 layer, port 7, L total = 3	3	3	Total 2 other layers;-port 8 (from UE X)-port 11 (from UE Y)
	4	1 layer, port 8, L total = 3	3	3	Total 2 other layers;-port 7 (from UE X)-port 11 (from UE Y)
	5	1 layer, port 11, L total = 3	3	2or 3	Total 2 other layers; ports 7-8 (from UE X or UE X + Y)
	6	1 layer, port 7, L total = 4	4	4	Total 3 other layers; -port 8 (from UE X)-port 11 (from UE Y)-port 13 (from UE Z)
	7	1 layer, port 8, L total = 4	4	4	Total 3 other layers; -port 7 (from UE X)-port 11 (from UE Y)-port 13 (from UE Z)
	8	1 layer, port 11, L total = 4	4	3 or 4	Total 3 other layers; ports 7 ~ 8 / port 13 (from UE X + Y or UE X + Y + Z)
	9	1 layer, port 13, L total = 4	4	3 or 4	Total 3 other layers; ports 7 ~ 8 / port 11 (from UE X + Y or UE X + Y + Z)
	10	2 layers, ports 7 ~ 8	2	One	N / A
	11	3 layers, ports 7-9	3	One	N / A
	12	4 layers, ports 7 ~ 10	4	One	N / A
Twocodeword	0	2 layers, ports 7 ~ 8, L total = 2	2	One	N / A
	One	2 layers, ports 7 ~ 8, L total = 3	3	2	Total 1 other layer; port 11 (from UE X)
	2	2 layers, ports 7 ~ 8, L total = 4	4	2 or 3	Total 2 other layers;-ports 11 & 13 (from UE X or UE X + Y)
	3	2 layers, ports 11 & 13, L total = 4	4	2	Total 2 other layers;-ports 7 ~ 8 (from UE X)
	4	3 layers, ports 7-9	3	One	N / A
	5	4 layers, ports 7 ~ 10	4	One	N / A
	6	5 layers, ports 7 ~ 11	5	One	N / A
	7	6 layers, ports 7 ~ 12	6	One	N / A
	8	7 layers, ports 7 ~ 13	7	One	N / A
	9	8 layers, ports 7 ~ 14	8	One	N / A

As shown in Table 9 or Table 10, the order of each index value expressed in total of 13 for one codeword and 10 for two codewords may be reversed. For example, the positions of index "4" and index "5" can be interchanged. However, although the order of the indexes is reversed, as mentioned in Tables 4 and 5, the total number of branches shown in Table 9 or Table 10 for each codeword (13 for one codeword and two for each codeword). Total 10) and its contents will be the same.

An antenna port number and a scrambling ID may be configured as follows to distinguish up to four layers allocated by the eNodeB 110 to transmit a reference signal in a specific resource region of the MU-MIMO environment.

Method 1) A set of four antenna ports using the same pattern of antenna ports 7 to 14 and separated by OCC as shown in Tables 8 to 10 (eg {7,8 used in Tables 8 to 10) , 11,13}) to distinguish up to four layers

Method 2) As shown in Tables 3 to 5, for the antenna ports 7 and 8, the scrambling ID is added to 1 in addition to 0 to use it to distinguish up to 4 layers.

Since the current LTE system uses Method 2, backward compatability with an existing communication system (ex. LTE) may be a problem when only Method 1 as described in Tables 8 to 10 is used. . Therefore, in consideration of backward compatability with the existing communication system, Method 1 (Table 8 to Table 10, which are included in the control information and actually signaled are the index values of Table 9) and Method 2 (Tables 3 to 5, What is actually signaled by being included in the control information may set both index values of Table 4) and use only one of them. This will require 1 bit of additional signaling to inform the UE whether Method 1 is used or Method 2 is used. This signaling may be included in the existing control information and may be transmitted to each UE through RRC (Radio Resource Control) signaling.

Also, as mentioned above, instead of setting both Method 1 and Method 2 and using one of them through additional signaling, a table may be constructed considering Method 1 and Method 2 simultaneously. Tables 11 to 13 below illustrate a configuration for this, and may configure the reference signal information 230 of the control information 200 through this.

Using the same pattern of antenna ports 7-14 and using a set of four antenna ports separated by OCC (eg {7,8,11,13} used in Tables 8-10), In the case of configuring the reference signal information 230 of the control information 200 simultaneously considering the use of the case 1 in addition to the case of the scrambling ID is 0 for the antenna ports 7 and 8, Table 3 is replaced with Table 11. Table 4 may be replaced by Table 12 and Table 6 may be replaced by Table 13.

Table 11

Total number of layers	All configurable cases for given total number of layers
	Case	SU- or MU-MIMO	UE (s) in MIMO	Pre-define case
One	Case 1-1	SU-MIMO (1UE)	UE A: 1 layer	(7,0)
2	Case 2-1	SU-MIMO (1UE)	UE A: 2 layers	(7-8,0)
	Case 2-2	MU-MIMO (2UEs)	UE A: 1 layer	(7,0)
			UE B: 1 layer	(8,0)
3	Case 3-1	SU-MIMO (1UE)	UE A: 3 layers	(7-9,0)
	Case 3-2	MU-MIMO (2UEs)	UE A: 2 layers	(7-8,0)
			UE B: 1 layer	(7,1) or (11,0)
	Case 3-3	MU-MIMO (3UEs)	UE A: 1 layer	(7,0)
			UE B: 1 layer	(8,0)
			UE C: 1 layer	(7,1) or (11,0)
4	Case 4-1	SU-MIMO (1UE)	UE A: 4 layers	(7-10,0)
	Case 4-2	MU-MIMO (2UEs)	UE A: 2 layers	(7-8,0)
			UE B: 2 layers	(7 ~ 8,1) or (11 & 13,0)
	Case 4-3	MU-MIMO (3UEs)	UE A: 2 layers	(7-8,0)
			UE B: 1 layer	(7,1) or (11,0)
			UE C: 1 layer	(8,1) or (13,0)
	Case 4-4	MU-MIMO (4UEs)	UE A: 1 layer	(7,0)
			UE B: 1 layer	(8,0)
			UE C: 1 layer	(7,1) or (11,0)
			UE D: 1 layer	(8,1) or (13,0)
5	Case 5-1	SU-MIMO (1UE)	UE A: 5 layers	(7 ~ 11,0)
6	Case 6-1	SU-MIMO (1UE)	UE A: 6 layers	(7-12,0)
7	Case 7-1	SU-MIMO (1UE)	UE A: 7 layers	(7-13,0)
8	Case 8-1	SU-MIMO (1UE)	UE A: 8 layers	(7-14,0)

Compared to Table 4, Table 11 shows (11,0) or (13,) for the seven pairs of antenna port number and scrambling ID (7,1) and (8,1), as indicated by underlined and bold text. Seven cases of 0) were added.

On the other hand, in comparison with Table 5, Table 12 shows four cases (indices = 6, 11, 12 and two codewords when using one codeword) as indicated by underline and bold text. ) Was added. In Table 12, the table on the left is for using one codeword (CW), and the table on the right is for using two codewords (CW).

Table 12

One codeword: Codeword 0 enabled, Codeword 1 disabled		Two codewords: Codeword 0 enabled, Codeword 1 enabled
Value	Message	Value	Message
0	1 layer, port 7, n SCID = 0, L total = 1	0	2 layers, ports 7 ~ 8, n SCID = 0, L total = 2
One	1 layer, port 7, n SCID = 0, L total = 2	One	2 layers, ports 7 ~ 8, n SCID = 0, L total = 3
2	1 layer, port 8, n SCID = 0, L total = 2	2	2 layers, ports 7 ~ 8, n SCID = 0, L total = 4
3	1 layer, port 7, n SCID = 0, L total = 3	3	2 layers, ports 7 ~ 8, n SCID = 1, L total = 4
4	1 layer, port 7, n SCID = 1, L total = 3	4	2 layers, ports 11 & 13, L total = 4
5	1 layer, port 8, n SCID = 0, L total = 3	5	3 layers, ports 7-9
6	1 layer, port 11, L total = 3	6	4 layers, ports 7 ~ 10
7	1 layer, port 7, n SCID = 0, L total = 4	7	5 layers, ports 7 ~ 11
8	1 layer, port 7, n SCID = 1, L total = 4	8	6 layers, ports 7 ~ 12
9	1 layer, port 8, n SCID = 0, L total = 4	9	7 layers, ports 7 ~ 13
10	1 layer, port 8, n SCID = 1, L total = 4	10	8 layers, ports 7 ~ 14
11	1 layer, port 11, L total = 4	11	Reserved
12	1 layer, port 13, L total = 4	12	Reserved
13	2 layers, ports 7 ~ 8	13	Reserved
14	3 layers, ports 7-9	14	Reserved
15	4 layers, ports 7 ~ 10	15	Reserved

Table 13

Since the reference signal information 230 of the control information 200 is configured using Tables 11 to 13, the eNodeB is connected to the corresponding UE and MU-MIMO by the antenna port number and the scrambling ID and uses other UE (s) using the same resource region. Backward compatibility with a communication system that separates up to four layers allocated for transmitting a reference signal to the C-link. In addition, this enables orthogonality that distinguishes up to four layers allocated for transmitting a reference signal to the UE and other UE (s) using the same resource region in MU-MIMO. I can guarantee more. In addition, even if the reference signal information 230 is configured as shown in Tables 11 to 13, the reference signal information 230 may be expressed using only 4 bits like other methods.

As shown in Table 12 or Table 13, the order of each index value expressed in total of 16 for one codeword and 11 for two codewords may be reversed. For example, the positions of index "4" and index "5" can be interchanged. However, even though the order of the indexes is reversed, as mentioned in Tables 4 and 5, the total number of branches shown for each codeword in Table 12 or Table 13 (16 for one codeword, two for each codeword). Total 11) and its contents will be the same.

Meanwhile, in Table 13, the case where the pair of the antenna port number and the scrambling ID is (7,1) and (11,0) is not distinguished, and a blind search may be required to distinguish them. Similarly, if the pairs of antenna port number and scrambling ID are (8,1) and (13,0), blind search may be required to distinguish them.

For example, if the number of layers of another UE is 2 for index “3” for one codeword, there are two cases: (antenna port number, scramble ID) = (8,0) / (7,1) Or blind search for (8,0) / (11,0) may be needed.

In addition, in the case where the number of layers of other UEs connected with MU-MIMO using the same resource region by MU-MIMO for the index “5” for one codeword is two, that is, (antenna port number, scramble ID) = ( A blind search may be needed to distinguish between 7,0) / (7,1) or (7,0) / (11,0).

In addition, in the case where the number of layers of other UEs connected with MU-MIMO for the index “7” for one codeword and using the same resource region is 3, two cases, (antenna port number, scramble ID) = ( A blind search may be needed to distinguish 8,0) / (7,1) / (8,1) or (8,0) / (11,0) / (13,0).

In addition, in the case where the number of layers of other UEs connected with MU-MIMO for the index “9” for one codeword and using the same resource region is 3, two cases, (antenna port number, scramble ID) = ( A blind search may be needed to distinguish between 7,0) / (7,1) / (8,1) or (7,0) / (11,0) / (13,0).

In addition, in the case where the number of layers of other UEs connected to MU-MIMO and using the same resource region for the index “1” for two codewords is 1, two cases, namely (antenna port number and scramble ID) = A blind search may be needed to distinguish between (7,1) or (11,0).

In addition, in the case where the number of layers of other UEs connected to MU-MIMO using the same resource region by MU-MIMO for the index “2” of two codewords is two, that is, two cases (antenna port number and scramble ID) A blind search may be needed to distinguish between (7,1) / (8,1) or (11,0) / (13,0).

Referring again to FIG. 1, for example, a particular UE 120-1 of the UEs 120-1,..., 120-n included in the wireless communication system 100 is shown in FIG. 2 from the eNodeB 110. The control information 200 of the DCI format may be received. The specific UE 120-1 may know which resource of which component carrier the eNodeB 110 has allocated to itself through the component carrier identifier 210 and the resource allocation information 220 included in the control information 200. . In addition, the UE 120-1 may include reference signal configuration information, SU-MIMO, or MU of another UE sharing the same resource together with its reference signal configuration information through the reference signal information 230 included in the control information 200. In MIMO, the total number of UEs connected to a specific UE and MU-MIMO and using the same resource region can be known.

In this case, the eNodeB 110 and the UEs 120-1,..., 120-n store at least one of Tables 4 and 5, 6, 7, 9, 10, 12, and 13, respectively, as the control information 200. When configuring the reference signal configuration information or extracting the reference signal configuration information, the reference signal configuration information corresponding to the index for the reference signal configuration information is stored from one of Tables 4 and 5, 6, 7, 9, 10, 12, and 13 stored. Able to know.

The eNodeB 110 transmits control signals 130-1, ..., 130-n, and transmits reference signals and data 140-1, ..., 140-n to the UEs 120-1, ..., 120-n. ) Can be sent.

3 is a diagram illustrating a structure of a transmitter for transmitting a reference signal in a MIMO environment according to an embodiment of the present invention.

Referring to FIG. 3, the transmitter 300 includes a reference signal (RS) sequence generator 310 and a resource element (RE) mapper 320. The transmitter 300 may be the eNodeB or the base station apparatus 110 shown in FIG. 1. In this case, the reference signal sequence generator 310 and the RE mapper 320 may be implemented by hardware or software integration.

The transmitter 300 of FIG. 3 may transmit signals through v layers.

The reference signal sequence generator 310 receives external information such as system information related to the reference signal sequence generation and a scrambling ID known from the reference signal information 230 and receives a reference signal sequence, for example, a DM-RS. Create a sequence. In this case, the reference signal information 230 may be configured through one of Table 4, Table 6, Table 9, and Table 12. The system information related to the generation of the reference signal sequence may include a cell ID, a slot number, the number of maximum resource blocks (RBs) used for downlink, a type of a cyclic prefix (CP), and the like. .

For example, antenna ports

In reference signal sequence r (m) generated by the reference signal sequence generator 310 may be defined by Equation 1.

Equation 1

In Equation 1

Is the maximum number of resource blocks (RB) used for downlink, and the pseudo-random sequence c (i) is a gold sequence based on a 31-stage linear feedback shift resistor (LFSR). Gold sequence) can be defined. m is an index value of the reference signal sequence generated from the reference signal sequence generator 310 and is a maximum value depending on the type of CP (ie, normal CP or extended CP). This may be defined differently.

The reference signal sequence generator 310 is an initial value of a gold sequence based on 31 LFSRs in each subframe.

Initialize Where n _s is the slot number in the subframe,

Is the physical cell ID. The scrambling ID n _SCID for antenna ports 7 and 8 may be 0 or 1 as shown in Table 14 below, and the scrambling ID n _SCID may be 0 for antenna ports 9 to 14. Table 14 below shows the scrambling ID field of the DCI format 200. At this time, the scrambling ID used by the eNodeB 110 when generating the reference signal sequence is included in the reference signal information 230 and transmitted to the UE as described above.

Table 14

Scrambling ID Field	n	SCID
0	0
One	One

The resource element (RE) mapper 320 knows from the system information and the reference signal information 230 related to mapping the reference signal sequence generated through the reference signal sequence generator 310 to the resource element RE. A reference signal sequence generated by receiving external information such as antenna port information, for example, a DM-RS sequence, is allocated to a time-frequency resource region. Subsequently, data symbols mapped to the resource elements RE and a reference signal such as a DM-RS are generated as OFDM signals and transmitted to each UE through an eNodeB.

In other words, data symbols mapped to resource elements (REs) and reference signals such as DM-RSs are transmitted to a plurality of UEs through Nt transmit antennas through inverse fast fourier transform (IFFT) and cyclic prefix (CP) insertion, respectively. Can be sent. In this case, a total of v layers may be allocated to n UEs, where n UEs 120-1,..., 120n share the same time / frequency resource region at the same time.

4 shows a resource element (k, l) used in DM-RS for a normal CP for antenna ports 7 to 10 to which the present invention is applied, and FIG. 5 is an antenna to which the present invention is applied. The resource element (k, l) used for DM-RS for extended CP for ports 7 and 8 is shown.

In the case of a normal CP, up to eight antenna ports (antenna ports 7 to 14) may be used, and antenna ports 7, 8, 11, and 13 are mapped to the same resource region as antenna port 7. Orthogonal sequences such as orthogonal cover codes (OCCs). In addition, antenna ports 9, 10, 12, and 14 are mapped to a resource region such as antenna port 9, and are divided into orthogonal sequences such as orthogonal cover codes (OCCs). The OCC may be configured differently according to each antenna port as shown in Table 17 below.

Table 17

Therefore, when the antenna port number is known, the resource region to which the automatically generated reference signal sequence is mapped and the orthogonal sequence used by Table 17 can be known. At this time, the antenna port number used by the eNodeB 110 when generating the reference signal sequence is included in the reference signal information 230 and transmitted to the UE as described above.

For example, in a normal CP, the resource element (RE) mapper 320 is assigned a frequency domain index n _PRB for antenna ports p = 7,8, ..., v + 6 corresponding to PDSCH transmission. As shown in FIG. 4, a portion of the reference signal sequence r ( m ) generated as in Equation 1 in the physical resource block RB having a complex-valued modulation symbols is shown.

(The value of the resource element ( k , l ) for antenna port p ). In the extended CP, the resource element (RE) mapper 320 also has an equation in the physical resource block (RB) having the frequency domain index n _PRB assigned for the PDSCH transmission for antenna ports 7 and 8. A portion of the reference signal sequence r ( m ) generated as in 1 is shown in FIG. 5 as a complex modulation symbol.

Can be mapped to In this case, DM-RS, which is a reference signal in an extended CP, may not be supported for antenna ports 9 to 14.

Although not shown, the resource element RE mapper 330 may allocate not only a reference signal sequence but also control information including data and reference signal information described above with reference to FIG. 2 to the time-frequency resource region.

6 is a block diagram of a receiving apparatus according to an embodiment of the present invention.

Referring to FIG. 6, in a wireless communication system, the receiver 600 may include a receiver processor 610, a resource element demapper 620, and a reference signal sequence extractor 630. The receiver 600 may be included in one of the UEs 120-1,..., 120-n described with reference to FIG. 1.

The reception processor 610 receives a signal through each antenna of the reception device.

The resource element demapper 620 is described with reference to FIGS. 4 and 5 using system information related to demapping a reference signal sequence from the resource element RE and antenna port information known from the reference signal information 230. De-mapping the reference signal sequence for each antenna port in the reverse order of the resource element allocation scheme by one of the schemes.

Although not shown, the resource element RE demapper 620 may demap not only a reference signal sequence but also control information including data and the aforementioned reference signal information.

The reference signal sequence extractor 630 extracts the reference signal sequence using system information related to the generation of the reference signal sequence and a scrambling ID known from the reference signal information 230.

Specifically, the reference signal information 230 of the received control information 200 is connected to MU-MIMO through one or more of Tables 4, 5, 6, 7, 9, 10, 12, and 13 to use the same resource area. The antenna port number and the scrambling ID, the SU-MIMO or MU-MIMO for the allocated layers to transmit the reference signal to the other UE (s) of the specific UE and the other UEs connected to the MU-MIMO using the same resource region. Since the total number, etc., the RS sequence extractor 630 removes interference from other UE (s) and extracts the RS sequence, thereby demodulating information for each antenna port in a multi-antenna system including a plurality of antennas. Demodulation information) can be obtained.

The demodulator not shown may demodulate data from the decoded data symbols using demodulation information for each antenna port obtained by the reference signal sequence extractor 630.

For example, if the _total number of layers allocated by the eNodeB 110 to transmit a reference signal in a specific resource region is R _total , and the number of UEs connected to MU-MIMO and using the same resource region is N,

( R _j is the number of layers of UE j). Since UE i knows the _total number of layers R _total and its number R _i , UE i is the number of interfering layers

To

This can be seen from

In addition, Tables 4 and 5, 6, 7, 9, 10, 12, and 13 may be connected to MU-MIMO through one or more of the layers allocated for transmitting a reference signal to other UE (s) using the same resource region. Since the antenna port number, the scrambling ID, the SU-MIMO or the MU-MIMO are connected to a specific UE and the MU-MIMO and the total number of other UEs using the same resource region can be known, interference cancellation can be performed.

7 is a signal flowchart for transmitting a reference signal according to an embodiment of the present invention.

Referring to FIG. 7, first, the eNodeB determines reference signal information (S710).

In this case, the reference signal information includes reference signal configuration information of a specific UE, such as the number of layers allocated to transmit a reference signal to a specific UE and antenna port number and scrambling ID for the layer, as shown in Tables 4, 6, 9, and 12. And eNodeB 110 may include a total number of UEs connected to a specific UE and MU-MIMO in SU-MIMO or MU-MIMO and using the same resource region.

The UE receiving the RS information may be assigned to the UE through one of Tables 4, 6, 9, and 12, and the number of layers allocated for transmitting the RS to the specific UE, an antenna port number, and a scrambling ID for the layer. Reference signal configuration information and the eNodeB 110 is connected to a specific UE and MU-MIMO in SU-MIMO or MU-MIMO, so that the total number of other UEs using the same resource region can be known. MU-MIMO as shown in Table 5 in conjunction with Table 4, Table 6, Table 10 in conjunction with Table 7, and Table 13 in conjunction with Table 12 by pre-defined rules. Also, reference signal configuration information of another UE, such as an antenna port number and a scrambling ID, for a layer allocated for transmitting a reference signal to other UE (s) using the same resource region can be obtained.

As described above, the reference signal includes a cell-specific reference signal (CRS), a UE-specific reference signal (DM-RS), and a channel state information reference signal (Channel State Information-). Reference Signal (CSI-RS), but will be described below using the DM-RS as a reference signal.

Next, the eNodeB generates control information represented by an index or indicator indicating the reference signal information determined in step S710 from one of Tables 4 and 6, 9, and 12 stored in advance (S720). In this case, as described with reference to FIG. 2, the control information may include other information, for example, an element carrier identifier (CIF) or resource allocation information.

Next, the eNodeB transmits downlink control information generated in step S720 to UEs through a physical downlink control channel (PDCCH) (S730).

As described above, a physical downlink control channel (PDCCH) carrying this control information is transmitted in an aggregation of one or more consecutive control channel elements (CCEs), and various PDCCHs as shown in Table 1 below. Format support

The eNodeB generates a reference signal related to the RS information and transmits it to UEs (S740). Since the process of generating and transmitting the DM-RS has been described with reference to FIGS. 3 to 5, a detailed description thereof will be omitted. In this case, the eNodeB may transmit data to the UEs together with the reference signal.

In FIG. 7, reference signal information is first determined, and an index indicating the same is included in the control information and transmitted, and the reference signal is generated and transmitted accordingly. However, first, the reference signal may be generated and transmitted, the reference signal information may be determined from the information on the reference signal, and an index indicating this may be included in the control information and transmitted. That is, the specific order in FIG. 7 may be reversed. However, the important order here is that the generated reference signal is transmitted and the reference signal information included in the control information as an index that can be determined and indicated is associated with each other.

8 is a signal flowchart for receiving a reference signal according to an embodiment of the present invention.

Referring to FIG. 8, a specific UE (user terminal) first receives control information including reference signal information expressed as an index from the eNodeB (S810).

Next, the specific UE (user terminal), using one of Tables 4, 6, 9, and 12 stored in advance, the specific UE corresponding to the index representing the reference signal information included in the control information received in step S810 Reference signal configuration information and eNodeB of the specific UE including the number of layers allocated to transmit the reference signal to the antenna, the antenna port number of the layer, and the scrambling ID for the layer The total number of layers allocated for transmitting a reference signal to other UE (s) connected to the UE and the MU-MIMO and using the same resource region is checked (S815).

Next, the specific UE receives a signal such as a reference signal through each antenna of the eNodeB (S820).

Next, the specific UE is connected to the corresponding UE and MU-MIMO, and the total number of layer (s) allocated to transmit the reference signal to other UE (s) using the same resource region transmits the reference signal to the specific UE. It is determined whether the number is greater than the number of layers allocated (S830). In operation S830, the specific UE may know that the former operates in the MU-MIMO mode when the former is larger than the latter, and operates in the SU-MIMO mode when the former and the latter are the same. In this case, step S830 may be performed before step S820.

When the former and the latter are the same in step S830 to operate in the SU-MIMO mode, a specific UE is determined from system information and reference signal information related to demapping the reference signal sequence from the resource element RE of the signal received in step S820. Demapping resource elements (REs) including a reference signal sequence for each antenna port in the reverse order of the resource element allocation scheme according to one of the methods described with reference to FIGS. A reference signal sequence is extracted using the scrambling ID known from the system information related to the sequence generation and the reference signal information 230 (S840).

On the other hand, when the former is greater than the latter in step S830 to operate in the MU-MIMO mode, the specific UE receiving the reference signal information to transmit the reference signal to a specific UE through one of Tables 4, 6, 9, 12 Reference signal configuration information of a specific UE such as the number of allocated layers, the antenna port number and the scrambling ID for the layer, and the eNodeB 110 are connected to the specific UE and the MU-MIMO in SU-MIMO or MU-MIMO, and the same resource region. In addition to knowing the total number of other UEs that use the Table 5, Table 10, Table 10, Table 10, Table 10, Table 9, and the interworking with Table 4, Table 6, and interworking with Table 6, according to a pre-defined rule Reference to other UEs, such as the antenna port number and the scrambling ID, for the layer allocated for transmitting reference signals to other UE (s) connected to MU-MIMO and using the same resource region as shown in Table 13 in conjunction with 12. signal You can also see the configuration information. Therefore, by using this to remove interference from other UE (s) from the received signal, de-mapping the resource element (RE) including the reference signal sequence from the entire resource element (RE) of the received signal, and generates the reference signal sequence and The interference is extracted from other UE (s) by using the related system information and the scrambling ID known from the reference signal information 230, and the reference signal sequence is extracted (S850).

In operation S850, a specific UE may remove interference from other UE (s) from the received signal and extract a reference signal sequence by a minimum mean sequence error (MMSE) detection method, but is not limited thereto. In other words, a specific UE is connected to MU-MIMO, and antenna port number and scrambling ID for layers allocated to transmit a reference signal to another UE using the same resource region, and a specific UE and MU in SU-MIMO or MU-MIMO. Interference cancellation may be performed from the MMSE scheme through the total number of other UEs connected to the MIMO and using the same resource region.

Next, a specific UE obtains demodulation information for each antenna port in a multi-antenna system including a plurality of antennas through a reference signal sequence extracted by one of steps S840 and S850 (S860). The specific UE may demodulate data from the decoded data symbol using demodulation information for each antenna port obtained in step S860.

In the above-described embodiments, the eNodeB 110 transmits a reference signal such as DM-RS to the UE (s) in a MIMO environment, and the number of layers used to transmit the reference signal to a specific UE and antennas for the layer. Reference signal including port and scrambling ID and the total number of layers allocated for transmitting a reference signal to UE (s) using the same resource region, including specific UE or specific UE in SU-MIMO or MU-MIMO, etc. Disclosed are a method and apparatus for signaling configuration information in downlink control information in a PDCCH DCI format, a method for receiving the control information, and an apparatus thereof.

In the above-described embodiments, when the reference signal is decoded in a specific terminal (UE) in MU-MIMO, the interference is detected by the other terminal (UE), thereby eliminating the interference, thereby improving the operation performance in the MU-MIMO mode. have.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes 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.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority under No. 119 (a) (35 USC § 119 (a)) of the US Patent Act No. 10-2011-0042183, filed with Korea on 3 May 2011. All content is incorporated by reference in this patent application. In addition, if this patent application claims priority to a country other than the United States for the same reason, all its contents are incorporated into this patent application by reference.

Claims (14)

1. In a method for transmitting a reference signal by a base station in a wireless communication system,

   Generating and transmitting a reference signal for a specific terminal; And

   The number of layers allocated for transmitting a reference signal to the specific terminal, the antenna port number and the scrambling ID for the layer, and the reference signal to terminals using the same resource region, including the specific terminal or the specific terminal. Transmitting reference signal information indicating the total number of all the layers allocated in the transmission;

   And the antenna port number and the scrambling ID for the all assigned layers are predetermined according to the total number of all allocated layers.
2. The method of claim 1,

   The total number of all layers allocated for transmitting a reference signal to the specific terminal or terminals using the same resource region including the specific terminal and the number of layers allocated for transmitting the reference signal to the specific terminal are limited. How to feature.
3. The method of claim 1,

   The reference signal information may further include a total number of terminals using the same resource region.
4. The method of claim 1,

   The antenna port number and the scrambling ID for the allocated all layers are predetermined as follows.

   In the SU-MIMO (Single User Multiple Input Multiple Output), (antenna port number, scrambling ID) for the all-allocated layers is the total number of all-allocated layers v = (7,0),... , using (v + 6,0),

   (Antenna port number, scrambling ID) for the allocated all layers in MU-MIMO (Multi User-MIMO) uses (7,0) when the total number of all allocated layers is 1 → (7,0). When the total number of all layers is 2 → (7,0), (8,0) is used, and when the total number of all allocated layers is 3 → (7,0), (8,0), (7 , 1), and the total number of all allocated layers is 4 → (7,0), (8,0), (7,1), (8,1).
5. The method of claim 1,

   The antenna port number and the scrambling ID for the allocated all layers are predetermined as follows.

   (Antenna port number, scrambling ID) for the all-allocated layers in SU-MIMO is the total number of the all-allocated layers v = (7,0),... , using (v + 6,0),

   (Antenna port number, scrambling ID) for the all allocated layers in MU-MIMO is used when the total number of all allocated layers is 1 → (7,0), and the total number of all allocated layers is 2 If (7,0), (8,0) is used, and the total number of all allocated layers is 3 → (7,0), (8,0), (11,0) is used If the total number of all allocated layers is 4 → (7,0), (8,0), (11,0), (13,0) are used.
6. The method of claim 1,

   The reference signal is characterized in that the DM-RS (Demodulation Reference Signal).
7. In a method for receiving a reference signal by the terminal in a wireless communication system,

   The number of layers allocated by the base station to transmit the reference signal to the terminal, the antenna port number and the scrambling ID for the layer, and the reference signal is transmitted to the terminals using the same resource region, including the terminal or the terminal Receiving reference signal information from the base station indicating the total number of allotted layers;

   Receiving a reference signal from the base station; And

   Extracting the reference signal sequence using the reference signal information,

   And an antenna port number and a scrambling ID for all layers allocated by the base station are predetermined according to the total number of all assigned layers.
8. The method of claim 7, wherein

   That the base station is limited to the total number of all layers allocated in transmitting the reference signal to the terminal or the terminal using the same resource region including the terminal and the number of layers allocated in transmitting the reference signal to the terminal How to feature.
9. The method of claim 7, wherein

   The reference signal information may further include a total number of terminals using the same resource region.
10. The method of claim 7, wherein

    The antenna port number and the scrambling ID for the entire layer allocated by the base station is characterized in that predetermined as follows.

    (Antenna port number, scrambling ID) for the all-allocated layers in SU-MIMO is the total number of the all-allocated layers v = (7,0),... , using (v + 6,0),

    (Antenna port number, scrambling ID) for the all allocated layers in MU-MIMO is used when the total number of all allocated layers is 1 → (7,0), and the total number of all allocated layers is 2 If (7,0), (8,0) is used, and the total number of all assigned layers is 3 → (7,0), (8,0), (7,1) is used When the total number of all the allocated layers is 4 → (7,0), (8,0), (7,1), (8,1) are used.
11. The method of claim 7, wherein

    The antenna port number and the scrambling ID for the entire layer allocated by the base station is characterized in that predetermined as follows.

    (Antenna port number, scrambling ID) for the all-allocated layers in SU-MIMO is the total number of the all-allocated layers v = (7,0),... , using (v + 6,0),

    (Antenna port number, scrambling ID) for the all allocated layers in MU-MIMO is used when the total number of all allocated layers is 1 → (7,0), and the total number of all allocated layers is 2 If (7,0), (8,0) is used, and the total number of all allocated layers is 3 → (7,0), (8,0), (11,0) is used If the total number of all allocated layers is 4 → (7,0), (8,0), (11,0), (13,0) are used.
12. The method of claim 7, wherein

    The reference signal is characterized in that the DM-RS (Demodulation Reference Signal).
13. An apparatus for transmitting a reference signal to a terminal in a wireless communication system,

    A reference signal sequence generator for generating a reference signal sequence; And

    A resource element (RE) mapper for allocating the generated RS sequence to a time-frequency resource region;

    The reference signal sequence generator and the resource element mapper generate a reference signal sequence based on the reference signal information transmitted to the UE and allocate it to the time-frequency resource region.

    The reference signal information refers to the number of layers allocated for transmitting a reference signal to the terminal, an antenna port number and a scrambling ID for the layer, and terminals using the same resource region including the terminal or the terminal. It is characterized by indicating the total number of all layers allocated in the signal transmission,

    And an antenna port number and a scrambling ID for the all assigned layers are predetermined according to the total number of all allocated layers.
14. A terminal for receiving a reference signal from a base station in a wireless communication system,

    A reception processor for receiving a signal from the base station;

    A resource element (RE) demapper for demapping a resource element (RE) of the received signal; And

    A reference signal sequence extracting unit for extracting a reference signal sequence from a resource element including a reference signal among the de-mapped resource elements,

    The resource element (RE) demapper and the reference signal sequence extractor extract the reference signal sequence from the resource element (RE) to which the reference signal sequence is mapped using the reference signal information received from the base station.

    The reference signal information refers to the number of layers allocated for transmitting a reference signal to the terminal, an antenna port number and a scrambling ID for the layer, and terminals using the same resource region including the terminal or the terminal. It indicates that the total number of all layers allocated in the signal transmission,

    And an antenna port number and a scrambling ID for the all assigned layers are predetermined according to the total number of all allocated layers.

Images