WO2019070094A1 - Method for channel or interference measurement in wireless communication system and apparatus therefor - Google Patents

Abstract

A method for channel measurement using a port-wise channel and interference measurement resource and reporting in a wireless communication system according to one embodiment of the present invention is performed by a terminal and may comprise the steps of: receiving a configuration related to a port-wise channel and interference measurement resource, wherein the port-wise channel and interference measurement resource corresponds to a port-specific independent interference assumption and comprises a terminal-group-specific channel and interference measurement resource; and measuring port-specific channel and interference in the port-wise channel and interference measurement resource, and reporting a measurement result.

Description

Method and apparatus for channel or interference measurement in a wireless communication system

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for channel or interference measurement.

As more and more communication devices require greater communication capacity, there is a need for improved mobile broadband communication over existing radio access technology (RAT). In addition, massive MTC (Machine Type Communications), which provides various services by connecting many devices and objects, is one of the major issues to be considered in next generation communication. In addition, a communication system design considering reliability / latency sensitive services is being discussed. In this way, the introduction of the next generation RAT considering eMBB, massive MTC (mMTC), URLLC (ultra-reliable and low latency communication) is being discussed. In the present invention, (New RAT).

The present invention proposes a method for channel or interference measurement.

The technical problems to be solved by the present invention are not limited to the technical problems and other technical problems which are not mentioned can be understood by those skilled in the art from the following description.

A method of measuring and reporting a channel using a port-wise channel and an interference measurement resource in a wireless communication system according to an embodiment of the present invention, the method comprising: performing a port-wise channel and interference Receiving a setting associated with the measurement resource; Wherein the port-wide channel and interference measurement resources correspond to independent interference assumptions for each port and include terminal-group specific channel and interference measurement resources, and wherein the port-wide channel and the interference measurement resource Measuring channel and interference, and reporting measurement results.

Additionally or alternatively, the UE-group specific channel and interference measurement resources may be for calibrating a previously reported channel quality indicator (CQI).

Additionally or alternatively, the UE-group specific channel and interference measurement resources may be set semi-persistently and may be enabled or disabled by signaling from the network.

Additionally or alternatively, if the UE is not scheduled for UL transmission or DL reception, the method assumes that all the ports of the UE-group specific channel and the interference measurement resource are ports through which the interfering signal is transmitted, And < / RTI >

Additionally or alternatively, the settings related to the UE-group specific channel and interference measurement resources may include a port for channel measurement and an index or number of ports for interference measurement, and the UE- The resource-related settings may be included in an aperiodic reference signal indication for the resource.

Additionally or alternatively, the port of the terminal-group specific channel and the interference measurement resource corresponds one-to-one with the demodulation reference signal port, the demodulation reference signal port for the terminal corresponds to the port for channel measurement, It can be used as a port for interference measurement.

Additionally or alternatively, the settings related to the UE-group specific channel and interference measurement resources may include information on the number of co-scheduled multi-user (MU) layers or the total number of MU layers.

A terminal for performing channel measurement in a wireless communication system according to another embodiment of the present invention, the terminal comprising: a transmitter and a receiver; And a processor configured to control the transmitter and the receiver, the processor receiving a setting related to a port-wise channel and an interference measurement resource, the port-wise channel and the interference measurement resource being independent of each port And includes terminal-group specific channel and interference measurement resources, and can measure the channel and interference for each port in the port-wise channel and the interference measurement resource, and report the measurement result.

Additionally or alternatively, the UE-group specific channel and interference measurement resources may be for calibrating a previously reported channel quality indicator (CQI).

Additionally or alternatively, the UE-group specific channel and interference measurement resources may be set semi-persistently and may be enabled or disabled by signaling from the network.

Additionally or alternatively, if the UE is not scheduled for UL transmission or DL reception, the processor assumes all ports of the UE-group specific channel and interfering measurement resources as the port through which the interfering signal is transmitted, Can be performed.

Additionally or alternatively, the settings related to the UE-group specific channel and interference measurement resources may include a port for channel measurement and an index or number of ports for interference measurement, and the UE- The resource-related settings may be included in an aperiodic reference signal indication for the resource.

Additionally or alternatively, the port of the terminal-group specific channel and the interference measurement resource corresponds one-to-one with the demodulation reference signal port, the demodulation reference signal port for the terminal corresponds to the port for channel measurement, It can be used as a port for interference measurement.

Additionally or alternatively, the settings related to the UE-group specific channel and interference measurement resources may include information on the number of co-scheduled multi-user (MU) layers or the total number of MU layers.

A computer-readable storage medium storing computer program code according to another embodiment of the present invention, wherein the computer program code is executable by a processor of a communications device, wherein: the communications device comprises: a port-wise channel and an interference measurement resource And wherein the port-wise channel and the interference measurement resources correspond to independent interference assumptions for each port, and include terminal-group specific channel and interference measurement resources, and wherein the port-wise channel and interference measurement resources It is possible to measure channels and interference for each port in the measurement resource and report the measurement result.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the present invention by those skilled in the art. And can be understood and understood.

Embodiments of the present invention can efficiently process channel and interference measurements.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

1 shows an example of a radio frame structure used in a wireless communication system.

2 illustrates an example of a downlink / uplink (DL / UL) slot structure in a wireless communication system.

FIG. 3 illustrates a downlink (DL) subframe structure used in a 3GPP LTE / LTE-A system.

FIG. 4 shows an example of an uplink (UL) subframe structure used in the 3GPP LTE / LTE-A system.

5 is a reference diagram for explaining a self-contained slot structure in an NR system.

FIGS. 6 and 7 are reference views for explaining a connection method of a TXRU (Transceiver Unit) and an antenna element.

8 is a reference diagram for explaining the hybrid beam forming.

Fig. 9 shows a situation in which a plurality of different resources and a reporting band do not coincide.

Figure 10 shows a block diagram of an apparatus for implementing an embodiment (s) of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or may be shown in block diagram form, centering on the core functionality of each structure and device, to avoid obscuring the concepts of the present invention. In the following description, the same components are denoted by the same reference numerals throughout the specification.

In the present invention, a user equipment (UE) may be fixed or mobile and various devices communicating with a base station (BS) to transmit and receive user data and / or various control information. The UE may be a terminal equipment, a mobile station, a mobile terminal, a user terminal, a subscriber station, a wireless device, a personal digital assistant (PDA) modem, a handheld device, and the like. Also, in the present invention, a BS is generally a fixed station that communicates with a UE and / or another BS, and exchanges various data and control information by communicating with a UE and another BS. The BS includes an Advanced Base Station (ABS), a Node-B, an evolved-NodeB, an ng-eNB, a next Generation NodeB, a Base Transceiver System (BTS) Point, a Processing Server (PS), and a transmission point (TP). In the following description of the present invention, a BS is referred to as an eNB.

In the present invention, a node refers to a fixed point that can communicate with a user equipment and transmit / receive a wireless signal. Various types of eNBs can be used as nodes regardless of its name. For example, BS, NB, eNB, pico-cell eNB (PeNB), home eNB (HeNB), relay, repeater, and the like can be nodes. Also, the node may not be an eNB. For example, a radio remote head (RRH), a radio remote unit (RRU). RRH, RRU, etc. generally have a power level lower than the power level of the eNB. RRH / RRU and RRH / RRU) are generally connected to the eNB as a dedicated line such as an optical cable. Therefore, compared with cooperative communication by eNBs connected by radio lines in general, the RRH / RRU and the eNB Can be performed smoothly. At least one antenna is installed in one node. The antenna may be a physical antenna, an antenna port, a virtual antenna, or an antenna group. A node is also called a point. Unlike a conventional centralized antenna system (CAS) (i.e., a single-node system) in which antennas are centrally located in a base station and controlled by one eNB controller, The plurality of nodes are usually spaced apart by a predetermined distance or more. The plurality of nodes may be managed by at least one eNB or eNB controller that controls operation of each node or that schedules data to be transmitted / received through each node. Each node can be connected to an eNB or an eNB controller that manages the node through a cable or a dedicated line. In a multi-node system, the same cell identifier (ID) may be used or a different cell ID may be used for signal transmission / reception to / from a plurality of nodes. When a plurality of nodes have the same cell ID, each of the plurality of nodes operates as a certain antenna group of one cell. In a multi-node system, if the nodes have different cell IDs, then this multi-node system can be viewed as a multi-cell (e.g., macro-cell / femto-cell / pico-cell) system. If multiple cells formed by a plurality of nodes are configured to be overlaid according to coverage, the network formed by the multiple cells is called a multi-tier network in particular. The cell ID of the RRH / RRU and the cell ID of the eNB may be the same or different. When the RRH / RRU uses different cell IDs, the RRH / RRU and the eNB both operate as independent base stations.

In the multi-node system of the present invention to be described below, one or more eNBs or eNB controllers connected to a plurality of nodes may control the plurality of nodes to transmit or receive signals simultaneously to the UE through some or all of the plurality of nodes . There is a difference between the multi-node systems depending on the entity of each node, the implementation type of each node, etc. However, in that a plurality of nodes participate in providing communication services to UEs on a predetermined time-frequency resource together, Systems differ from single node systems (e.g., CAS, conventional MIMO systems, conventional relay systems, conventional repeater systems, etc.). Accordingly, embodiments of the present invention relating to a method for performing data cooperative transmission using some or all of a plurality of nodes can be applied to various kinds of multi-node systems. For example, although a node usually refers to an antenna group located apart from another node by a predetermined distance or more, embodiments of the present invention described below may be applied to a case where a node means an arbitrary antenna group regardless of an interval. For example, in the case of an eNB having an X-pol (cross polarized) antenna, the eNB may control a node composed of a H-pol antenna and a node composed of a V-pol antenna, and embodiments of the present invention may be applied .

A node that transmits / receives a signal through a plurality of transmission (Tx) / reception (Rx) nodes, transmits / receives a signal through at least one node selected from a plurality of transmission / reception nodes, ENB MIMO or CoMP (Coordinated Multi-Point TX / RX) is a communication scheme capable of differentiating nodes receiving uplink signals. Cooperative transmission schemes among the inter-node cooperative communication can be roughly divided into JP (joint processing) and scheduling coordination. The former can be divided into JT (joint transmission) / JR (joint reception) and DPS (dynamic point selection), and the latter can be divided into coordinated scheduling (CS) and coordinated beamforming (CB). DPS is also called DCS (dynamic cell selection). As compared to other cooperative communication schemes, when a JP among the inter-node cooperative communication schemes is performed, a wider variety of communication environments can be formed. In JP, JT refers to a communication technique in which a plurality of nodes transmit the same stream to a UE, and JR refers to a communication technique in which a plurality of nodes receive the same stream from a UE. The UE / eNB combines signals received from the plurality of nodes to recover the stream. In the case of JT / JR, since the same stream is transmitted to / from a plurality of nodes, the reliability of signal transmission can be improved by transmission diversity. JP DPS refers to a communication scheme in which a signal is transmitted / received through a node selected according to a specific rule among a plurality of nodes. In the case of DPS, the reliability of signal transmission can be improved since a node with a good channel condition between the UE and the node will typically be selected as the communication node.

In the present invention, a cell refers to a geographical area in which one or more nodes provide communication services. Accordingly, in the present invention, communication with a specific cell may mean communicating with an eNB or a node providing a communication service to the specific cell. Also, the downlink / uplink signals of a particular cell are downlink / uplink signals to / from an eNB or a node that provides communication services to the particular cell. A cell providing an uplink / downlink communication service to a UE is called a serving cell. The channel state / quality of a specific cell means the channel state / quality of a channel or a communication link formed between an eNB or a node providing the communication service to the particular cell and the UE. In a 3GPP LTE-A based system, a UE transmits a downlink channel state from a specific node to an antenna port (s) of the particular node on a channel CSI-RS (Channel State Information Reference Signal) resource allocated to the particular node (CSI-RS). ≪ / RTI > In general, neighboring nodes transmit corresponding CSI-RS resources on mutually orthogonal CSI-RS resources. The fact that the CSI-RS resources are orthogonal can be determined by the CSI-RS by assigning a CSI-RS resource configuration, a subframe offset, and a transmission period specifying a symbol carrying a CSI-RS and a subcarrier. A subframe configuration for specifying the subframes, and a CSI-RS sequence are different from each other.

In the present invention, the Physical Downlink Control Channel (PDCCH) / Physical Control Format Indicator CHannel / Physical Uplink Shared CHannel (PHICH) / Physical Downlink Shared CHannel (PDSCH) A Physical Uplink Control CHannel (PUCCH), a Physical Uplink Control Channel (PUSCH), a Physical Uplink Control Channel (PUSCH), and a Physical Uplink Control Channel (PUSCH) (Uplink Shared CHannel) / PRACH (Physical Random Access CHannel) refers to a set of time-frequency resources or a set of resource elements each carrying Uplink Control Information (UCI) / uplink data / random access signals. , A PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH RE or a time-frequency resource or resource element RE allocated to or belonging to the PDCCH / PCFICH / PHICH / PDSCH / Hereinafter, the expression that the user equipment transmits a PUCCH / PUSCH / PRACH is referred to as a PUCCH / PUCCH / PRACH or a PUCCH / PUCCH / PRACH through an uplink control information / uplink The expression that the eNB transmits PDCCH / PCFICH / PHICH / PDSCH is used to transmit downlink data / control information on the PDCCH / PCFICH / PHICH / PDSCH, Is used in the same sense.

1 shows an example of a radio frame structure used in a wireless communication system. Particularly, FIG. 1 (a) shows a frame structure for a frequency division duplex (FDD) used in a 3GPP LTE / LTE-A system and FIG. 1 Time division duplex (TDD) frame structure.

Referring to FIG. 1, the radio frame used in the 3GPP LTE / LTE-A system has a length of 10 ms (307200 Ts) and consists of 10 equal sized subframes (SF). 10 subframes within one radio frame may be assigned respective numbers. Here, Ts represents the sampling time, and is represented by Ts = 1 / (2048 * 15 kHz). Each subframe is 1 ms long and consists of two slots. 20 slots in one radio frame can be sequentially numbered from 0 to 19. [ Each slot has a length of 0.5 ms. The time for transmitting one subframe is defined as a transmission time interval (TTI). The time resource may be classified by a radio frame number (or a radio frame index), a subframe number (also referred to as a subframe number), a slot number (or a slot index), and the like.

The wireless frame may be configured differently according to the duplex mode. For example, in the FDD mode, since the downlink transmission and the uplink transmission are divided by frequency, the radio frame includes only one of the downlink subframe and the uplink subframe for a specific frequency band. In the TDD mode, since the downlink transmission and the uplink transmission are divided by time, the radio frame includes both the downlink subframe and the uplink subframe for a specific frequency band.

Table 1 illustrates the DL-UL configuration of subframes in a radio frame in TDD mode.

DL-UL configuration

Downlink-to-Uplink Switch-point periodicity

Subframe number

0

One

2

3

4

5

6

7

8

9

0

5ms

D

S

U

U

U

D

S

U

U

U

One

5ms

D

S

U

U

D

D

S

U

U

D

2

5ms

D

S

U

D

D

D

S

U

D

D

3

10ms

D

S

U

U

U

D

D

D

D

D

4

10ms

D

S

U

U

D

D

D

D

D

D

5

10ms

D

S

U

D

D

D

D

D

D

D

6

5ms

D

S

U

U

U

D

S

U

U

D

In Table 1, D denotes a downlink subframe, U denotes an uplink subframe, and S denotes a special subframe. The specific subframe includes three fields of Downlink Pilot Time Slot (DwPTS), Guard Period (GP), and UpPTS (Uplink Pilot Time Slot). DwPTS is a time interval reserved for downlink transmission, and UpPTS is a time interval reserved for uplink transmission. Table 2 illustrates the configuration of the singular frames.

Special subframe configuration	Normal cyclic prefix in downlink			Extended cyclic prefix in downlink
	DwPTS	UpPTS		DwPTS	UpPTS
		Normal cyclic prefix in uplink	Extended cyclic prefix in uplink		Normal cyclic prefix in uplink	Extended cyclic prefix in uplink
0	6592 · T s	2192 · T s	2560 · T s	7680 · T s	2192 · T s	2560 · T s
One	19760 · T s			20480 · T s
2	21952 · T s			23040 · T s
3	24144 · T s			25600 · T s
4	26336 · T s			7680 · T s	4384 · T s	5120 · T s
5	6592 · T s	4384 · T s	5120 · T s	20480 · T s
6	19760 · T s			23040 · T s
7	21952 · T s			12800 · T s
8	24144 · T s			-	-	-
9	13168 · T s			-	-	-

2 illustrates an example of a downlink / uplink (DL / UL) slot structure in a wireless communication system. In particular, Figure 2 shows the structure of the resource grid of the 3GPP LTE / LTE-A system. There is one resource grid per antenna port.

Referring to FIG. 2, a slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time domain and a plurality of resource blocks (RBs) in a frequency domain. The OFDM symbol also means one symbol period. Referring to FIG. 2, the signals transmitted in each slot are

*

Subcarriers < RTI ID = 0.0 >

And can be represented by a resource grid composed of OFDM symbols. here,

Denotes the number of resource blocks (RBs) in the downlink slot,

Represents the number of RBs in the UL slot.

Wow

Depends on the DL transmission bandwidth and the UL transmission bandwidth, respectively.

Denotes the number of OFDM symbols in the downlink slot,

Denotes the number of OFDM symbols in the UL slot.

Represents the number of sub-carriers constituting one RB.

The OFDM symbol may be referred to as an OFDM symbol, an SC-FDM (Single Carrier Frequency Division Multiplexing) symbol, or the like according to a multiple access scheme. The number of OFDM symbols included in one slot can be variously changed according to the channel bandwidth and the length of the cyclic prefix (CP). For example, one slot includes seven OFDM symbols in the case of a normal CP, whereas one slot includes six OFDM symbols in the case of an extended CP. Although FIG. 2 illustrates a subframe in which one slot is composed of seven OFDM symbols for convenience of description, embodiments of the present invention may be applied to subframes having a different number of OFDM symbols in a similar manner. Referring to FIG. 2, each OFDM symbol includes, in the frequency domain,

*

Lt; / RTI > subcarriers. The types of subcarriers can be divided into data subcarriers for data transmission, reference signal subcarriers for transmission of reference signals, guard bands, and null subcarriers for direct current (DC) components . The null subcarrier for the DC component is a subcarrier that is left unused and is mapped to a carrier frequency (f0) in an OFDM signal generation process or a frequency up conversion process. The carrier frequency is also referred to as the center frequency.

Day RB is in the time domain

(E. G., 7) consecutive OFDM symbols and is defined by c (e. G., Twelve) consecutive subcarriers in the frequency domain. For reference, a resource composed of one OFDM symbol and one subcarrier is referred to as a resource element (RE) or a tone. Therefore, one RB

*

Resource elements. Each resource element in the resource grid can be uniquely defined by an index pair (k, 1) in one slot. k is in the frequency domain from 0

*

-1, and l is an index given from 0 to

-1.

In one subframe

Two RBs, one in each of two slots of the subframe occupying consecutive identical subcarriers, are called a physical resource block (PRB) pair. The two RBs constituting the PRB pair have the same PRB number (or PRB index (index)). VRB is a kind of logical resource allocation unit introduced for resource allocation. VRB has the same size as PRB. According to the method of mapping the VRB to the PRB, the VRB is divided into a localized type VRB and a distributed type VRB. Localized type VRBs are directly mapped to PRBs so that VRB numbers (also referred to as VRB indexes) correspond directly to PRB numbers. That is, n _PRB = n _VRB . VRBs of localized type include 0 to

-1, < / RTI >

=

to be. Therefore, according to the localization mapping method, VRBs having the same VRB number are mapped to PRBs of the same PRB number in the first slot and the second slot. On the other hand, distributed type VRBs are interleaved and mapped to PRBs. Therefore, the distributed type VRB having the same VRB number can be mapped to different numbers of PRBs in the first slot and the second slot. Two PRBs, which are located in two slots of a subframe and have the same VRB number, are called a VRB pair.

FIG. 3 illustrates a downlink (DL) subframe structure used in a 3GPP LTE / LTE-A system.

Referring to FIG. 3, a DL subframe is divided into a control region and a data region in the time domain. Referring to FIG. 3, a maximum of 3 (or 4) OFDM symbols located at a first position in a first slot of a subframe corresponds to a control region to which a control channel is allocated. Hereinafter, a resource region available for PDCCH transmission in a DL subframe is referred to as a PDCCH region. The remaining OFDM symbols other than the OFDM symbol (s) used as a control region correspond to a data region to which PDSCH (Physical Downlink Shared CHannel) is allocated. Hereinafter, a resource region usable for PDSCH transmission in a DL subframe is referred to as a PDSCH region. Examples of the DL control channel used in the 3GPP LTE include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), and the like. The PCFICH carries information about the number of OFDM symbols transmitted in the first OFDM symbol of the subframe and used for transmission of the control channel in the subframe. The PHICH carries an HARQ (Hybrid Automatic Repeat Request) ACK / NACK (acknowledgment / negative-acknowledgment) signal in response to the UL transmission.

The control information transmitted through the PDCCH is referred to as downlink control information (DCI). The DCI includes resource allocation information and other control information for the UE or UE group. For example, the DCI may include a transport format and resource allocation information of a downlink shared channel (DL-SCH), a transport format and resource allocation information of an uplink shared channel (UL-SCH), a paging channel channel assignment information, upper layer control message resource allocation information, such as paging information on the channel, PCH, system information on the DL-SCH, random access response transmitted on the PDSCH, A Transmit Control Command Set, a Transmit Power Control command, an activation indication information of a Voice over IP (VoIP), and a Downlink Assignment Index (DAI). A transmission format and resource allocation information of a downlink shared channel (DL-SCH), which is also referred to as DL scheduling information or a DL grant, may be a UL shared channel (UL-SCH) The transmission format and resource allocation information are also referred to as UL scheduling information or UL grant. The DCI carried by one PDCCH differs in size and usage according to the DCI format, and its size may vary according to the coding rate. In the current 3GPP LTE system, various formats such as formats 0 and 4 for the uplink and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, 3 and 3A for the downlink are defined. (RB allocation), a modulation coding scheme (MCS), a redundancy version (RV), a new data indicator (NDI), a transmit power control (TPC), a cyclic shift DMRS control information such as a downlink index, a shift demodulation reference signal, an UL index, a channel quality information (CQI) request, a DL assignment index, a HARQ process number, a transmitted precoding matrix indicator (TPMI) The selected combination is transmitted to the UE as downlink control information.

Generally, the DCI format that can be transmitted to the UE depends on the transmission mode (TM) configured for the UE. In other words, not all DCI formats may be used for UEs configured in a particular transport mode, but only certain DCI format (s) corresponding to the particular transport mode may be used.

The PDCCH is transmitted on an aggregation of one or more contiguous control channel elements (CCEs). The CCE is a logical allocation unit used to provide the PDCCH with a coding rate based on radio channel conditions. The CCE corresponds to a plurality of resource element groups (REG). For example, one CCE corresponds to nine REGs, and one REG corresponds to four REs. In the 3GPP LTE system, a set of CCEs in which a PDCCH can be located for each UE is defined. A set of CCEs in which a UE can discover its PDCCH is referred to as a PDCCH search space, simply a Search Space (SS). Individual resources to which the PDCCH can be transmitted within the search space are referred to as PDCCH candidates. The collection of PDCCH candidates to be monitored by the UE is defined as a search space. In the 3GPP LTE / LTE-A system, the search space for each DCI format can have different sizes, and a dedicated search space and a common search space are defined. The dedicated search space is a UE-specific search space and is configured for each individual UE. The common search space is configured for a plurality of UEs. The aggregation level that defines the search space is as follows.

Search Space S K (L)			Number of PDCCH candidates M (L)
Type	Aggregation Level L	Size [in CCEs]
UE-specific	One	6	6
	2	12	6
	4	8	2
	8	16	2
Common	4	16	4
	8	16	2

One PDCCH candidate corresponds to 1, 2, 4 or 8 CCEs depending on the CCE aggregation level. The eNB transmits the actual PDCCH (DCI) on any PDCCH candidate in the search space, and the UE monitors the search space to find the PDCCH (DCI). Here, the monitoring means to attempt decoding of each PDCCH in the search space according to all the monitored DCI formats. The UE may monitor the plurality of PDCCHs and detect its own PDCCH. Basically, since the UE does not know the location where its PDCCH is transmitted, it tries to decode all PDCCHs of the corresponding DCI format every PDCCH until it detects a PDCCH with its own identifier. This process is called blind detection blind decoding " (BD)).

The eNB may transmit data for the UE or the UE group through the data area. Data transmitted through the data area is also referred to as user data. For transmission of user data, a PDSCH (Physical Downlink Shared CHannel) may be allocated to the data area. A paging channel (PCH) and a downlink-shared channel (DL-SCH) are transmitted through the PDSCH. The UE may decode the control information transmitted through the PDCCH and read the data transmitted through the PDSCH. Information indicating to which UE or UE group the data of the PDSCH is transmitted, how the UE or UE group should receive and decode the PDSCH data, and the like are included in the PDCCH and transmitted. For example, if a particular PDCCH is masked with a cyclic redundancy check (CRC) with an RNTI (Radio Network Temporary Identity) of "A" and a radio resource (e.g., frequency location) Assume that information on data to be transmitted using format information (e.g., transport block size, modulation scheme, coding information, etc.) is transmitted through a specific DL sub-frame. The UE monitors the PDCCH using the RNTI information it owns, and the UE having the RNTI of " A " detects the PDCCH and transmits the PDSCH indicated by " B " .

In order to demodulate the signal received from the eNB, a reference signal (RS) to be compared with the data signal is needed. Reference signal refers to a signal of a predetermined special waveform that the eNB transmits to the UE or to the eNB by the eNB and the UE, and is also called a pilot. The reference signals are divided into cell-specific RSs shared by all UEs in the cell and demodulation RSs (DM RS) dedicated to specific UEs. The DM RS transmitted by the eNB for demodulating the downlink data for a specific UE is also referred to as a UE-specific RS. In the downlink, the DM RS and the CRS may be transmitted together, but only one of them may be transmitted. However, when only the DM RS is transmitted without the CRS in the downlink, the DM RS transmitted using the same precoder as the data can be used only for demodulation purposes, and therefore, a channel measurement RS must be separately provided. For example, in 3GPP LTE (-A), an additional measurement RS, CSI-RS, is transmitted to the UE so that the UE can measure channel state information. The CSI-RS is transmitted every predetermined transmission period consisting of a plurality of subframes, unlike the CRS transmitted for each subframe, based on the fact that the channel state is not relatively varied with time.

FIG. 4 shows an example of an uplink (UL) subframe structure used in the 3GPP LTE / LTE-A system.

Referring to FIG. 4, the UL subframe may be divided into a control domain and a data domain in the frequency domain. One or several physical uplink control channels (PUCCHs) may be assigned to the control region to carry uplink control information (UCI). One or several physical uplink shared channels (PUSCHs) may be allocated to the data area of the UL subframe to carry user data.

In the UL subframe, subcarriers far away from the direct current (DC) subcarrier are used as a control region. In other words, subcarriers located at both ends of the UL transmission bandwidth are allocated for transmission of uplink control information. The DC subcarrier is a component that is left unused for signal transmission and is mapped to the carrier frequency f0 in the frequency up conversion process. In one subframe, a PUCCH for one UE is allocated to an RB pair belonging to resources operating at a single carrier frequency, and RBs belonging to the RB pair occupy different subcarriers in two slots. The PUCCH allocated as described above is expressed as the RB pair allocated to the PUCCH is frequency-hopped at the slot boundary. However, when frequency hopping is not applied, the RB pairs occupy the same subcarrier.

The PUCCH may be used to transmit the following control information.

- SR (Scheduling Request): Information used for requesting uplink UL-SCH resources. OOK (On-Off Keying) method.

- HARQ-ACK: A response to the PDCCH and / or a response to a downlink data packet (e.g., codeword) on the PDSCH. Indicates whether PDCCH or PDSCH has been successfully received. In response to a single downlink codeword, one bit of HARQ-ACK is transmitted and two bits of HARQ-ACK are transmitted in response to two downlink codewords. The HARQ-ACK response includes positive ACK (simply ACK), negative ACK (NACK), DTX (Discontinuous Transmission) or NACK / DTX. Here, the term HARQ-ACK is mixed with HARQ ACK / NACK and ACK / NACK.

- CSI (Channel State Information): Feedback information for the downlink channel. Multiple Input Multiple Output (MIMO) -related feedback information includes RI (Rank Indicator) and PMI (Precoding Matrix Indicator).

The amount of uplink control information (UCI) that the UE can transmit in the subframe depends on the number of SC-FDMAs available for control information transmission. The SC-FDMA available for the UCI means the remaining SC-FDMA symbol except for the SC-FDMA symbol for the reference signal transmission in the subframe, and in the case of the subframe configured with the SRS (Sounding Reference Signal) -FDMA symbols are excluded. The reference signal is used for coherent detection of the PUCCH. PUCCH supports various formats depending on the information to be transmitted.

Table 4 shows the mapping relationship between the PUCCH format and the UCI in the LTE / LTE-A system.

PUCCH format	Modulation scheme	Number of bits per subframe	Usage	Etc.
One	N / A	N / A (exist or absent)	SR (Scheduling Request)
1a	BPSK	One	ACK / NACK orSR + ACK / NACK	One codeword
1b
QPSK	2	ACK / NACK orSR + ACK / NACK		Two codeword
2	QPSK	20	CQI / PMI / RI	Joint coding ACK / NACK (extended CP)
2a	QPSK + BPSK	21	CQI / PMI / RI + ACK / NACK	Normal CP only
2b	QPSK + QPSK	22	CQI / PMI / RI + ACK / NACK	Normal CP only
3	QPSK	48	ACK / NACK or SR + ACK / NACK orCQI / PMI / RI + ACK / NACK

Referring to Table 4, the PUCCH format 1 sequence is mainly used for transmitting ACK / NACK information, and the PUCCH format 2 sequence is mainly used for carrying channel state information (CSI) such as CQI / PMI / RI , The PUCCH format 3 sequence is mainly used to transmit ACK / NACK information.

A reference signal (RS)

When a packet is transmitted in a wireless communication system, since the transmitted packet is transmitted through a wireless channel, signal distortion may occur in the transmission process. In order to properly receive the distorted signal at the receiving side, the distortion should be corrected in the received signal using the channel information. In order to determine the channel information, a method is used in which a signal known to both the transmitting side and the receiving side is transmitted, and channel information is detected with a degree of distortion when the signal is received through the channel. The signal is referred to as a pilot signal or a reference signal.

When transmitting and receiving data using multiple antennas, it is necessary to know the channel condition between each transmitting antenna and the receiving antenna so that a correct signal can be received. Therefore, there is a separate reference signal for each transmission antenna, more specifically, for each antenna port (antenna port).

The reference signal may be divided into an uplink reference signal and a downlink reference signal. In the current LTE system, as an uplink reference signal,

i) a demodulation reference signal (DM-RS) for channel estimation for coherent demodulation of information transmitted via PUSCH and PUCCH,

ii) The base station has a Sounding Reference Signal (SRS) for the network to measure the uplink channel quality at different frequencies.

On the other hand, in the downlink reference signal,

i) a cell-specific reference signal (CRS) shared by all terminals in a cell,

ii) a UE-specific reference signal for a specific UE only;

iii) a DeModulation-Reference Signal (DM-RS) transmitted for coherent demodulation when the PDSCH is transmitted;

iv) Channel State Information-Reference Signal (CSI-RS) for transmitting channel state information (CSI) when the downlink DMRS is transmitted.

v) MBSFN Reference Signal (MBSFN Reference Signal) transmitted for coherent demodulation on a signal transmitted in MBSFN (Multimedia Broadcast Single Frequency Network) mode,

vi) There is a positioning reference signal used to estimate the geographical location information of the terminal.

The reference signal can be roughly classified into two types according to its purpose. There are a target reference signal for channel information acquisition and a reference signal used for data demodulation. The former can acquire channel information on the downlink because the UE can acquire the channel information. Therefore, the former must receive the reference signal even if the terminal does not receive the downlink data in a specific subframe. It is also used in situations such as handover. The latter is a reference signal sent together with a corresponding resource when a base station transmits a downlink, and the terminal can demodulate data by performing channel measurement by receiving the reference signal. This reference signal should be transmitted in the area where data is transmitted.

CSI Reporting

In the 3GPP LTE (-A) system, a user equipment (UE) is defined to report channel state information (CSI) to a base station (BS), and channel state information (CSI) Refers to information that can indicate the quality of a channel (or a link). For example, a rank indicator (RI), a precoding matrix indicator (PMI), a channel quality indicator (CQI), and the like. Here, RI denotes rank information of a channel, which means the number of streams that the UE receives through the same time-frequency resource. Since this value is determined by being dependent on the long term fading of the channel, it is fed back from the UE to the BS with a period longer than the PMI, CQI, usually longer. The PMI is a value reflecting the channel space characteristic and indicates a preferred precoding index of the UE based on a metric such as SINR. The CQI is a value representing the strength of a channel, and generally refers to a reception SINR that can be obtained when the BS uses the PMI.

Based on the measurement of the radio channel, the UE computes the preferred PMI and RI that can derive an optimal or maximum transmission rate if used by the BS under the current channel conditions, and feeds the calculated PMI and RI back to the BS do. Here, the CQI refers to a modulation and coding scheme that provides an acceptable packet error probability for the feedback PMI / RI.

On the other hand, in LTE-A systems that are expected to include more precise MU-MIMO and explicit CoMP operations, the current CSI feedback is defined in LTE and therefore does not adequately support such newly introduced operations. As the requirements for CSI feedback accuracy become increasingly difficult to obtain sufficient MU-MIMO or CoMP throughput gains, PMI can be used for long term / wideband PMI (W ₁ ) and short term short term / subband PMI (W ₂ ). In other words, the final PMI is expressed as a function of W ₁ and W ₂ . For example, the final PMI W can be defined as: W = W ₁ * W ₂ or W = W ₂ * W ₁ . Therefore, in LTE-A, CSI will be composed of RI, W ₁ , W ₂ and CQI.

Table 5 shows the uplink channels used for CSI transmission in the 3GPP LTE (-A) system.

Scheduling method	Periodic CSI transmission	Aperiodic CSI transmission
Frequency non-selective	PUCCH	-
Frequency selective	PUCCH	PUSCH

Referring to Table 5, the CSI can be transmitted using a physical uplink control channel (PUCCH) at a predetermined period in an upper layer, and can be periodically transmitted to a physical uplink shared channel Shared Channel, PUSCH). When the CSI is transmitted on the PUSCH, it is possible only in a frequency selective scheduling scheme and an aperiodic CSI transmission. Hereinafter, a CSI transmission scheme according to a scheduling scheme and periodicity will be described.

1) CQI / PMI / RI transmission through PUSCH after receiving CSI transmission request control signal (CSI request)

A control signal requesting transmission of CSI to a PUSCH scheduling control signal (UL Grant) transmitted in a PDCCH signal may be included. The following table shows the UE mode when transmitting CQI, PMI, and RI through PUSCH.

		PMI Feedback Type
		No PMI	Single PMI	Multiple PMIs
PUSCH CQI Feedback Type	Wideband (Wideband CQI)			Mode 1 - 2 RI 1st wideband CQI (4 bits) 2nd wideband CQI (4 bits) if RI > 1 N * Subband PMI (4 bits) (if 8Tx Ant, N * subband W2 + wideband W1)
	UE selected (Subband CQI)	Mode 2-0 RI (Best-M CQI: Average CQI for M SBs selected from a total of N SBs) Best-M CQI (4 bits) + Best-M CQI index (L bit)		Mode 2-2 RI 1st wideband CQI (4bit) + Best-M CQI (2bit) 2nd wideband CQI (4bit) + Best-M CQI (2bit) ) + Best-M PMI (4bit) (if 8Tx Ant, wideband W2 + Best-M W2 + wideband W1)
	Higher Layer-configured (Subband CQI)	Mode 3-0 RI (only for Open-loop SM) 1st wideband CQI (4bit) + N * subbandCQI (2bit)	Mode 3-1 RI 1st wideband CQI (4bit) + N * subband CQI (2bit) 2nd wideband CQI (4bit) + N * subbandCQI (2bit) if RI> 1 Wideband PMI (4bit) (if 8Tx Ant, wideband W2 + wideband W1 )	Mode 3-2 RI 1st wideband CQI (4 bits) + N * subband CQI (2 bits) 2nd wideband CQI (4 bits) + N * subband CQI (2 bits) (if 8Tx Ant, N * subband W2 + wideband W1)

The transmission mode in Table 6 is selected in the upper layer, and CQI / PMI / RI are all transmitted in the same PUSCH subframe. Hereinafter, an uplink transmission method of the UE according to each mode will be described.

Mode 1-2 (Mode 1-2) shows a case where a precoding matrix is selected on the assumption that data is transmitted only through subbands for each subband. The UE generates the CQI by assuming a selected precoding matrix for the entire band (set S) designated by the system band or an upper layer. In Mode 1-2, the UE can transmit the CQI and the PMI value of each subband. At this time, the size of each subband may vary depending on the size of the system band.

The UE in mode 2-0 (Mode 2-0) can select M subbands preferred for the designated band (set S) designated by the system band or the upper layer. The UE may generate one CQI value on the assumption that it transmits data for the selected M subbands. The UE further preferably reports one CQI (wideband CQI) value for the system band or set S. When there are a plurality of codewords for the selected M subbands, the UE defines a CQI value for each codeword in a differential format.

At this time, the difference CQI value is determined by a difference between the index corresponding to the C sub-band for the selected M subbands and the wideband CQI (Wideband CQI) index.

In the mode 2-0, the UE transmits information on the positions of the selected M subbands, one CQI value for the selected M subbands, and the CQI value generated for the entire band or the designated band (set S) to the BS . At this time, the size and the M value of the subband can be changed according to the size of the system band.

A mode 2-2 (Mode 2-2) UE selects a single precoding matrix for M preferred subbands and M preferred subbands at the same time, assuming that the data is transmitted through M preferred subbands . At this time, the CQI values for the M preferred subbands are defined for each codeword. In addition, the UE further generates a wideband CQI value for the system band or the designated band (set S).

The UE in mode 2-2 receives information on the location of M preferred subbands, one CQI value for selected M subbands, a single PMI for M preferred subbands, a wideband PMI, and a wideband CQI value BS. At this time, the size and the M value of the subband can be changed according to the size of the system band.

The UE in mode 3-0 (Mode 3-0) generates a wideband CQI value. The UE generates a CQI value for each subband on the assumption that data is transmitted through each subband. At this time, even if RI> 1, the CQI value represents only the CQI value for the first codeword.

A UE in mode 3-1 (Mode 3-1) generates a single precoding matrix for a system band or a designated band (set S). The UE assumes a single precoding matrix generated for each subband, and generates a subband CQI for each codeword. In addition, the UE may assume a single precoding matrix and generate a wideband CQI. The CQI value of each subband can be expressed in a differential format. The subband CQI value is calculated as the difference between the subband CQI index and the wideband CQI index. At this time, the size of the sub-band may vary depending on the size of the system band.

The UE in mode 3-2 (mode 3-2) generates a precoding matrix for each subband, instead of a single precoding matrix for the entire band, as compared with mode 3-1.

2) Periodic CQI / PMI / RI transmission through PUCCH

The UE may periodically transmit CSI (e.g., precoding type indicator (CQI) / precoding indicator (PTI) and / or RI information) to the BS via the PUCCH. If the UE receives a control signal to transmit user data, the UE may transmit the CQI via the PUCCH. The CQI / PMI / PTI / RI can be transmitted by one of the modes defined in the following table, even if the control signal is transmitted through the PUSCH.

		PMI feedback type
		No PMI	Single PMI
PUCCH CQI feedback type	Broadband (broadband CQI)	Mode 1-0	Mode 1-1
	UE selection (subband CQI)	Mode 2-0	Mode 2-1

The UE may have a transmission mode as shown in Table 7. < tb > < TABLE > Referring to Table 7, in the case of Mode 2-0 (Mode 2-0) and Mode 2-1 (Mode 2-1), a Bandwidth Part (BP) is a set of subbands located consecutively in the frequency domain System band or the designated band (set S). In Table 7, the size of each subband, the size of BP, and the number of BPs may vary depending on the size of the system band. Also, the UE transmits the CQIs in the frequency domain in the ascending order so as to cover the system band or the designated band (set S).

Depending on the combination of CQI / PMI / PTI / RI transmissions, the UE may have the following PUCCH transmission types.

i) Type 1: Transmits the subband CQI (SB-CQI) of Mode 2-0 (Mode 2-0) and Mode 2-1 (Mode 2-1).

ii) Type 1a: transmits subband CQI and second PMI

iii) Type 2, Type 2b, Type 2c: Broadband CQI and PMI (WB-CQI / PMI) are transmitted.

iv) Type 2a: Broadband PMI is transmitted.

v) Type 3: Transmit the RI.

vi) Type 4: Broadband CQI is transmitted.

vii) Type 5: transmit RI and wideband PMI.

viii) Type 6: transmits RI and PTI.

ix) Type 7: CSI-RS resource indicator (CRI) and RI are transmitted.

x) Type 8: CRI, RI and broadband PMI are transmitted.

xi) Type 9: CRI, RI and PTI (precode type indication) are transmitted.

xii) Type 10: transmits CRI.

When the UE transmits a wideband CQI / PMI to the RI, the CQI / PMI is transmitted in a subframe having different periods and offsets. In addition, when RI and the wideband CQI / PMI are to be transmitted in the same subframe, the CQI / PMI is not transmitted.

Non-Periodic CSI Request

The current LTE standard uses the 2-bit CSI request field in DCI format 0 or 4 to operate acyclic CSI feedback when considering a carrier aggregation (CA) environment. The UE interprets the CSI request field as two bits when a plurality of serving cells are set in the CA environment. If one of the TMs 1 to 9 is set for all CCs (Component Carriers), the aperiodic CSI feedback is triggered according to the values in Table 8 below, and TM 10 for at least one of the CCs If set, aperiodic CSI feedback is triggered according to the values in Table 9 below.

CSI Request Field Value	detailed description
'00'	Non-periodic CSI reporting is not triggered
'01'	Non-periodic CSI reporting is triggered on the serving cell
'10'	Aperiodic CSI reporting is triggered on the first set of serving cells set by the upper layer
'11'	Non-periodic CSI reporting is triggered on the second set of serving cells set by the upper layer

CSI Request Field Value	detailed description
'00'	Non-periodic CSI reporting is not triggered
'01'	Non-periodic CSI reporting is triggered for the set of CSI processes set by the upper layer for the serving cell
'10'	Non-periodic CSI reporting is triggered for the first set of CSI processes set by the upper layer
'11'	Non-periodic CSI reporting is triggered for the second set of CSI processes set by the upper layer

Newt (new radio technology; NR )

Hereinafter, a new radio access technology system will be described. As more and more communication devices require greater communication capacity, there is a need for improved mobile broadband communication over existing radio access technology (RAT). Massive Machine Type Communications (MTC), which provides a variety of services at any time and place by connecting multiple devices and objects, is also required. In addition, a design of a communication system considering a service / UE sensitive to reliability and latency has been proposed.

A new wireless access technology system has been proposed as a new wireless access technology considering enhanced mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication). Hereinafter, the present invention is referred to as New RAT or NR (New Radio) for the sake of convenience.

The NR system to which the present invention is applicable supports various OFDM Numerologies as shown in the following table. At this time, mu and cyclic prefix information for each carrier bandwidth part can be signaled for each of a downlink (DL) or uplink (UL). For example, mu and cyclic prefix information for the downlink carrier bandwidth part may be signaled via higher layer signaling DL-BWP-mu and DL-MWP-cp. As another example, the μ and cyclic prefix information for the uplink carrier bandwidth part may be signaled via higher layer signaling UL-BWP-mu and UL-MWP-cp.

Referring to the frame structure in NR, downlink and uplink transmission are composed of 10 ms long frames. The frame may be composed of 10 sub-frames each having a length of 1 ms. At this time, the number of consecutive OFDM symbols for each subframe is

to be.

Each frame may be composed of two half frames having the same size. At this time, each half-frame may be composed of sub-frames 0 - 4 and 5 - 9, respectively.

For subcarrier spacing [mu], the slots are arranged in ascending order within one subframe

Are numbered in ascending order within one frame

As shown in FIG. At this time, the number of consecutive OFDM symbols in one slot (

) Can be determined according to the cyclic prefix as shown in the following table. A starting slot in one subframe (

) Is the starting OFDM symbol (

) And the time dimension. Table 4 shows the number of OFDM symbols per slot / per frame / subframe for a normal cyclic prefix, and Table 5 shows the number of OFDM symbols per slot / frame / subframe for an extended cyclic prefix. Represents the number of OFDM symbols per subframe.

In the NR system to which the present invention can be applied, a self-contained slot structure can be applied with the slot structure as described above.

5 is a view showing a self-contained slot structure applicable to the present invention.

In FIG. 5, a hatched region (for example, symbol index = 0) represents a downlink control region, and a black region (for example, symbol index = 13) represents an uplink control region. Other areas (eg, symbol index = 1 to 12) may be used for downlink data transmission or for uplink data transmission.

According to this structure, the base station and the UE can sequentially perform DL transmission and UL transmission within one slot, and transmit and receive DL data within the one slot and transmit / receive UL ACK / NACK thereto. As a result, this structure reduces the time it takes to retransmit data when a data transmission error occurs, thereby minimizing the delay in final data transmission.

In such an autonomous slot structure, a time gap of a certain time length is required for the base station and the UE to switch from the transmission mode to the reception mode or to switch from the reception mode to the transmission mode. For this, some OFDM symbols at the time of switching from DL to UL in the self-supporting slot structure may be set as a guard period (GP).

In the above description, the case where the self-supporting slot structure includes both the DL control region and the UL control region has been described, but the control regions may be selectively included in the self-supporting slot structure. In other words, the self-supporting slot structure according to the present invention may include not only the DL control region and the UL control region but also the DL control region or the UL control region as shown in FIG.

As an example, a slot may have various slot formats. At this time, the OFDM symbol of each slot can be classified into a downlink (denoted by 'D'), a flexible (denoted by 'X'), and an uplink (denoted by 'U').

Therefore, it can be assumed that in the downlink slot, the UE generates downlink transmission only in 'D' and 'X' symbols. Similarly, in the uplink slot, the UE can assume that the uplink transmission occurs only in the 'U' and 'X' symbols.

Hereinafter, analog beamforming will be described.

In the millimeter wave (mmW), the wavelength is short, and it is possible to install a plurality of antenna elements in the same area. That is, since the wavelength is 1 cm in the 30 GHz band, a total of 100 antenna elements can be provided when a 2-dimensional array is arranged at intervals of 0.5 lambda (wavelength) on a panel of 5 * 5 cm. Accordingly, in a millimeter wave (mmW), a plurality of antenna elements can be used to increase the beamforming (BF) gain to increase the coverage or increase the throughput.

At this time, each antenna element may include TXRU (Transceiver Unit) so that transmission power and phase can be adjusted for each antenna element. Thus, each antenna element can perform independent beamforming for each frequency resource.

However, installing a TXRU in all 100 antenna elements has a problem in terms of cost effectiveness. Therefore, a scheme of mapping a plurality of antenna elements to one TXRU and adjusting the direction of a beam with an analog phase shifter is considered. Such an analog beamforming method has a disadvantage in that frequency selective beamforming is difficult because only one beam direction can be generated in all bands.

As a solution to this, a hybrid beamforming (hybrid BF) having B TXRUs that are fewer than Q antenna elements as an intermediate form of digital beamforming and analog beamforming can be considered. In this case, although there is a difference depending on a connection method of B TXRU and Q antenna elements, the direction of a beam that can be transmitted at the same time may be limited to B or less.

FIGS. 6 and 7 are views showing typical connection methods of the TXRU and the antenna element. Here, the TXRU virtualization model shows the relationship between the output signal of the TXRU and the output signal of the antenna element.

6 is a diagram illustrating a manner in which a TXRU is connected to a sub-array. In the case of FIG. 6, the antenna element is connected to only one TXRU.

7 is a diagram illustrating a manner in which TXRU is connected to all antenna elements. In the case of FIG. 7, the antenna element is connected to all TXRUs. At this time, the antenna element requires a separate adder as shown in FIG. 8 to be connected to all TXRUs.

In Figures 6 and 7, W represents a phase vector multiplied by an analog phase shifter. That is, W is a main parameter for determining the direction of the analog beamforming. Here, the mapping between the CSI-RS antenna port and the TXRUs may be 1: 1 or 1: to-many.

According to the configuration shown in FIG. 6, there is a disadvantage that beam focusing is difficult to focus, but the entire antenna configuration can be configured with a small cost.

According to the configuration of FIG. 7, there is an advantage that focusing of beam forming is easy. However, since TXRU is connected to all antenna elements, there is a disadvantage that the total cost increases.

When a plurality of antennas are used in the NR system to which the present invention is applicable, a hybrid beamforming technique combining digital beamforming and analog beamforming can be applied. At this time, the analog beamforming (or RF (Radio Frequency) beamforming) means an operation of performing precoding (or combining) in the RF stage. In the hybrid beamforming, the baseband stage and the RF stage perform precoding (or combining), respectively. This has the advantage of achieving performance close to digital beamforming while reducing the number of RF chains and the number of digital-to-analog (or analog-to-digital) converters.

For convenience of explanation, the hybrid beamforming structure may be represented by N transceiver units (TXRU) and M physical antennas. At this time, the digital beamforming for the L data layers to be transmitted by the transmitting end may be represented by an N * L (N by L) matrix. The converted N digital signals are then converted to an analog signal through a TXRU, and an analog beamforming represented by an M * N (M by N) matrix is applied to the converted signal.

Figure 8 is a simplified representation of a hybrid beamforming structure in terms of TXRU and physical antennas. In this case, the number of digital beams is L and the number of analog beams is N in FIG.

In addition, in the NR system, the base station is designed to change the analog beamforming on a symbol-by-symbol basis, thereby considering a method of supporting more efficient beamforming to a terminal located in a specific area. 8, when a specific N TXRU and M RF antennas are defined as one antenna panel, in the NR system according to the present invention, a plurality of antenna panels, to which independent hybrid beamforming is applicable, To be introduced.

As described above, when the base station utilizes a plurality of analog beams, an analog beam advantageous for signal reception may be different for each terminal. Accordingly, in the NR system to which the present invention can be applied, a base station applies a different analog beam for each symbol in a specific sub-frame SF (at least a synchronization signal, system information, paging, etc.) Beam sweeping operations are being considered to allow reception opportunities.

In New R. MIMO, resource settings, reporting settings, and measurement settings are defined for calculation and reporting of CSI. The resource settings include the setting of channel measurement resources (CMR) and interference measurement resources (IMR) such as CSI-RS. The reporting settings include settings (e.g., subband settings, reporting parameters such as RI / PMI / CQI, reporting timing, etc.) for the calculation and reporting of the CSI. The measurement settings select measurement resources within the resource settings to calculate / report the CSI of each reporting setting.

A representative example of the CMR is a non-zero power (NZP) CSI-RS, and a representative example of the IMR is a zero-power (ZP) CSI-RS based IMR. Both resources are supported in New Rat. In addition, the following port-wise NZP CSI-RS based IMR is defined in Newt MIMO.

The UE can be set up with a set of NZP CSI-RS ports for interference measurement.

- Whether to use a single CSI-RS resource for both channel and interference measurements, and whether to use individually configured CSI-RS resources for channel and interference measurements will be determined later

- The UE shall assume that each port of each set corresponds to an interference layer.

The choice of precoder to be applied on the NZP CSI-RS for interference measurement depends on the gNB implementation.

Port-Wise NZP CSI-RS based IMR emulates and transmits different interference for each port using NZP CSI-RS precoded by base station, unlike the existing ZP CSI-RS based IMR, Different interference is measured for each port and reflected in CSI calculation. Such an NZP CSI-RS based IMR is introduced to avoid setting too many ZP CSI-RS based IMRs in situations where the number of interference hypothesis to consider is too high, such as MU interference. In order to use this more efficiently, this specification proposes a method of defining and using two types of NZP CSI-RS based IMR as follows.

- RS type I and II

RS Type I: Terminal-dedicated P-IMR or CIMR

RS Type II: Terminal-Group-Specific CIMR

Each RS type includes an RS type I-terminal-dedicated P-IMR or CIMR for measuring / reporting a CSI reflecting UE's different interference assumptions regardless of scheduling, and a scheduling unit for measuring / reporting MU CSI, And an RS type II-UE-group-specific CIMR for reporting. For convenience, the following terminology is defined and used in this patent.

● P-IMR: Port-Wise NZP CSI-RS based IMR. Different interferences are transmitted through precoded NZP CSI-RS for each port (resource unit corresponding to each port). This does not include the required channel port.

● CIMR: P-IMR contains ports reflecting the required channels as some ports.

● C-port: port for channel measurement

● I-port: Port for interference measurement. NZP CSI-RS based IMR port.

● ZP-Port: Port for interference measurement. ZP CSI-RS based IMR port.

If the number of ports for the required channel measurement can be set within the range from 0 to the "maximum number of ports", the P-IMR in the configuration side can be freely set, The CIMR may be the same.

● RS Type I: Terminal - dedicated port group setting / instruction for P-IMR or CIMR

RS Type I is set UE-specific as an IMR for general CSI calculation / reporting (i.e., RI, PMI, CQI). RS Type I is set up with NZP CSI-RS for channel measurement and ZP CSI-RS-based IMR for interference measurement. This can be defined to measure at each port a general interference hypothesis, such as coordinated multiple transmission and reception (CoMP) interference, inter-beam interference, as well as MU interference. In this case, the UE regards the sum of the interference transmitted from each I-port of the corresponding NZP CSI-RS-based IMR as one interference and calculates / reports CSI or, if there is a separate setting / indication, It is possible to report the reflected CQI or to calculate / report a plurality of CQIs reflecting the interference of each port. This type of RS type I may include both cases with and without a C-port, and regardless of whether the CIMR / P-IMR is present, at least a separate CMR for the determination of the PMI may be included in the same reporting setting Respectively.

Such an aperiodic RS indication for RS Type I is triggered by the UL DCI, and the measurement result therefor, i.e. CSI, can be reported via UL resources.

● RS Type II: Terminal - Group - Set / Instruction of Port Group for Specific CIMR

RS Type II is defined for the calculation of MU CQI and is based on the previously reported SU CQI or preliminary MU CQI based on measured channel and interference measurements from the designated C-port and I- (CQI reflecting cross-layer interference from a co-scheduled terminal set assumed by the base station instead of the actual co-scheduled terminal). The RS type II can be shared by terminal groups scheduled or scheduled to be scheduled, thereby reducing RS overhead in terms of cells. In this case, a separate CMR or IMR is not additionally set in the report setting in which the corresponding RS type II is set, and it is possible to operate with only a single RS.

Such RS type II can be used as a semi-persistent CIMR. This can be activated / deactivated by a separate MAC CE or DCI, or the corresponding RS type II is activated at the moment the UE is scheduled, and the corresponding RS type II is deactivated at the same time as the UE finishes the scheduling It can be used without any signaling.

An unscheduled UE can also measure the corresponding RS type II in preparation for scheduling, which can be accomplished by instructing the UE to measure the corresponding RS type II through aperiodic RS indication or signaling including it. In this case, even if the corresponding resource setting is CIMR, the terminal can calculate / report the CSI by considering all ports as I-ports at that time. Such an aperiodic RS indication for RS Type II can be triggered with DL DCI. Particularly in such cases, other aperiodic CSI trigger / aperiodic CSI-RS triggers can be separated from those sent to the UL DCI.

The RS type II can presume that the interferences change every moment according to the co-scheduled UE, so that MR on (i.e. measurement at different timings The interference measurement result is regarded as a different interference, and the post-processing such as the averaging is not performed).

- base station / terminal operations associated with RS types I and II

The above-mentioned RS Type I and RS Type II can operate in the following manner.

1. The base station sets the following reporting settings to the terminal.

A. Set report setting 1 including RI / PMI / CQI report. The reporting settings use ZP CSI-RS based IMR or / and RS Type I with NZP CSI-RS for channel measurement.

B. Set reporting setting 2 including only CQI report. The reporting settings use RS Type II.

2. The base station requests CSI for reporting setting 1. (In case of periodic / semi-persistent CSI, a separate CSI request is not needed.) The UE measures the NZP CSI-RS, ZP CSI-RS based IMR and RS type I for the set channel measurement, / Report the CQI.

A. At this time, the terminal can report the MU CQI based on the interference of each port of the designated RS type I.

3. Based on the reported RI / PMI / CQI, the base station selects the MU terminal to be scheduled together and the rank / PMI to use for each terminal.

4. The BS determines the DMRS port to be used by each MS and performs initial PDSCH scheduling to each MS.

5. The base station requests CSI for reporting setting 2. (In case of periodic / semi-persistent CSI, there is no need for a separate CSI request.) The terminal assumes that the RS type II connected to the DMRS port assigned to itself is a C-port, and assumes that the remaining ports are I-ports To measure / report MU CQI.

6. The base station corrects the MCS of each terminal using the reported MU CQI.

Port setting method

The base station can set the same parameters as those set in the NZP CSI-RS, which are common to RS types I and II. For example, the following parameters can be set in common.

● Type of RS, for example, NZP CSI-RS, ZP CSI-RS based IMR, NZP CSI-RS based IMR (RS Type I, RS Type II)

● The total number of ports for this resource

● Code division multiplexing (CDM) length

• Timing behavior, eg, acyclic / semi-persistent / periodic

- If periodic / semi-persistent, also includes period and slot offset information.

Bandwidth part (BWP) index

● Frequency position / range in BWP

● RB-level density

● MR on / off

- Time / frequency MR can be signaled separately.

Power indicator (e.g., p_c)

- The power indicator here can be set differently for each port. In addition, the configuration of the C-port, I-port and ZP-port can be informed. The port configuration settings for each RS type can be as follows.

1.1 RS  Type I

The base station can set the port index of the RS type I ZP-port, C-port, I-port, or / and each port number to the UE through upper-layer signaling such as RRC. In this case, if only the port number is set without a separate port index, it can be mapped in order of ZP port-> C- port-> I- port. Alternatively, in order to dynamically set the corresponding port setting, the above-mentioned parameters may be set in the DCI by the DCI included in the aperiodic RS indication.

If it can be assumed that all of the ports of the resource are used (for example, zero power is transmitted to an unused port), one of the parameters described above may be excluded. For example, if the ZP-port is not included, only one of the number of C-ports or I-ports may be additionally set to set the number of C-ports and I-ports of the corresponding RS type I.

Or may be determined according to predetermined rules and / or external parameters, without port setting for explicit RS type I. For example, it can be mapped in order of ZP port-> C- port-> I- port for the set port numbers.

● Includes one ZP-port at the lowest indexed port

If the ZP-port is included in the same resource, the ZP-port must be defined on one of the ports that takes up CDM [1, 1, 1]. Since such a port typically uses the lowest indexed port, the ZP-port can be mapped to the lowest index.

● (after ZP-port) Set the port with the lowest index to the C-port

- The number of C-ports is assumed to be equal to the rank (or CW (codeword) number corresponding to the most recently reported RI).

- if the number of codewords is used as the number of C-ports and if the maximum rank that the terminal using MU scheduling can use from the SU point of view is equal to or less than the maximum number of layers in one codeword (e.g., 4 layers) The number of C-ports can also be fixed to one.

● The remaining ports after ZP-port and C-port are set to I-port

- If the C-port is not set, the number of I-ports can be determined in the same way. In other words, it can be assumed that the I-port is set for the remaining ports except the number of ports corresponding to the most recently reported RI.

- At this time, the same port mapping can be assumed even if the port on which the I-port of the P-IMR starts does not have the C-port.

This is especially useful when a plurality of terminals share a P-IMR. In this case, the signaling for the mapping between the C-port and the I-port needs to be transmitted to the UE, which can transmit the dynamic signaling such as DCI to the UE by including it in the corresponding RS indication.

1.2 RS  Type II

The base station can set the port index and / or the port number of the corresponding RS type II C-port, I-port, and ZP-port to the UE through upper-layer signaling such as RRC.

Characteristically, the ZP-port may not be included for RS type II. In this case, the UE can only feed back the CQI. In other words, the CQI only feedback is set in the corresponding reporting setting, and can be limited to the case set by the RS type II.

If there is a separate resource configuration other than RS type II, the resource may not be measured by the UE. Alternatively, in order to dynamically set the corresponding port setting, the above-mentioned parameters may be set in the DCI by the DCI included in the aperiodic RS indication.

The total number of RS type II ports can be limited to the maximum number of MU layers considering the number of antenna ports of the base station and the terminal and the maximum number of ports of the DMRS. In this case, each port of the RS type II is mapped to the DMRS port one to one . The terminal regards the RS type II port corresponding to the DMRS port used by itself as the C-port and the rest as the I-port. That is, the number of C-ports is set by the rank (or the number of CWs corresponding thereto) scheduled by itself.

In addition, the base station can inform the DCI of the total co-scheduled MU-layer number M, in which case M ports are considered as I-ports since the C-port, and the measurement results of the remaining ports can be ignored. Similarly, the base station can inform the UE of the total number of MU layers M_tot. In this case, since the C-port (M_tot - the number of C-ports) ports are regarded as I-ports, .

If the UE has not been scheduled for PDSCH reception even though the UE is instructed to measure the RS type II, the UE can regard the RS type II as having no C-port. In this case, a separate NZP CSI-RS for channel measurement or separate reporting settings is required.

A similar operation can be performed without setting the C-port, which needs to be set up for measurement of a channel requiring a separate resource. To this end, a separate NZP CSI-RS or a DMRS reflecting the precoding determined at the transmission and reception point (TRP) side may be designated as a resource for channel measurement. In this NZP CSI-RS, instead of the general NZP CSI-RS, an NZP CSI-RS configured with ports representing a channel in which a precoded NZP CSI-RS is required is configured similarly to the NZP CSI-RS-based IMR .

For RS types I and II, the C-port and I-port can be used differently at the RB-level. For example, an even-numbered-RB may be configured with a C-port, i.e., ports for channel measurement, and an odd-RB may comprise an I-port, i.e., ports for interference measurement. In this case, only port number setting for each port type is required without signaling / setting related to a separate port index.

For RS types I and II, the PRB bundling size can be informed to the terminal. This refers to a unit of resource in which the base station equally uses precoding in the frequency direction, which can be used by the UE to determine the unit of frequency direction resources that can assume the same interference. This can be assigned to the terminal via RRC / MAC / DCI signaling.

NZP  CSI- RS  base IMR  For port settings Signaling  And settings

The main use case of NZP CSI-RS based IMR is for more accurate MU CQI estimation. The ZP CSI-RS based IMR seems to be sufficient for interference measurements from other use cases, for example other TRP / beams. The previous agreement should be that the beam of the interfering terminal must be determined before the IM NZP CSI-RS transmission, since the terminal should assume that each port of each set corresponds to an interference layer. Since each of the MU terminals considers the required channel of the other terminal as interference, the interference beam as well as the required beam must be determined before the channel measurement NZP CSI-RS transmission. Otherwise, the reported MU-CQI is not accurate because some of the MU terminals report an MU-CQI assuming an outdated MU interference beam. Therefore, the UE must assume that the channel measurement NZP CSI-RS ports correspond to the required layer, which means that it assumes an identity precoder when calculating the MU-CQI. This principle is also applied to channel measurement NZP CSI-RS ports corresponding to the interference layer.

Next, we talk about which alternatives can make MU CQI improvements more efficient. For CIMR, one NZP CSI-RS may be shared with the MU terminals, and the port groups representing the channel and interference may be exchanged in a terminal-specific manner. For example, four CSI-RS ports are commonly set for terminal 0 and terminal 1, ports 0 and 1 are beamformed to the required beam of terminal 0, and ports 2 and 3 are beam- Shaped. Terminal 0 may be instructed to calculate CSI assuming that ports 0 and 1 are channels and ports 2 and 3 are interferers and UE1 may be instructed to intercept ports 2 and 3 as channels and ports 0 and 1 as interfering, Lt; / RTI > The set of ports for channel and interference measurements may be explicitly indicated or implicitly determined based on the previously reported RI.

In addition, while the above has been described for CIMR, the same signaling and configuration may be applied to P-IMR.

Explicit Without setting  Occation RS  Select type

If there is no explicit port configuration and / or explicit settings for RS type I and II in the configured IMR, you can decide whether to use any RS type I / II port configuration, as below.

- It can be regarded as RS type I if the corresponding terminal is not scheduled and RS type II when it is scheduled.

- Non-periodic resources can be regarded as RS type I, and semi-persistent resources can be regarded as RS type II.

- It can be regarded as RS type II if it includes C-port and RS type I if it does not include C-port.

> In this case, it is advantageous to set RS for separate channel measurement to calculate / report PMI / RI because it is difficult to calculate RI / PMI accurately with C-port in case of RS type I.

- If the same report setting includes a separate RS, especially RS for channel measurement, it can be regarded as RS Type I, other RS, especially if RS for channel measurement is not included.

- If the reporting setting includes CQI / PMI / RI feedback, it can be regarded as RS type II if it reports only RS type I and CQI.

- RS type I if the dynamic signaling that specifies the type I or II and parameters for it is sent to the UL DCI, or RS type II if it is sent to the DL DCI.

This considers reporting via PUSCH / PUCCH, respectively.

Similarly, if RS type I and RS type II are set simultaneously in the corresponding reporting settings, then you can select which RS type to use for actual CSI calculation / reporting in the same way.

RS  Base configuration for Type II RS  type)

A report using RS Type II can assume the following behavior (in the absence of a separate setting) as compared to RS Type I.

- Reporting CSI

In the case of RS type II, CQI only feedback is possible. In case of RS type II, since a separate channel measurement resource may not be set, the UE can report only the CQI without PMI / RI.

- Reporting frequency granularity

>> In the case of RS type II, it can be limited to broadband reporting.

- reporting timing

>> For RS type II, the reporting timing can be limited to 0 or 1 slots (from DCI trigger point). In the case of the above-described CQI only feedback, since there is no need to calculate the PMI / RI, the time required for calculating the CSI is small. Therefore, in case of non-periodic CSI reporting for RS type II, the CSI can use the PUSCH resource in the same slot if it is the next slot immediately after the measurement time or the self-contained slot even if there is no separate timing signaling As shown in FIG. In particular, this case can be limited to CSI only cases without PUSCH data. This applies equally to periodic / semi-persistent reporting, so that CSI can be reported using the PUCCH resource of the slot or the next slot.

- Reporting Container

In the case of RS type II, feedback via the PUCCH may limit transmission or reporting resources. This can perform feedback through the PUCCH resource without additional scheduling, especially when operating as the semi-persistent IMR described above.

Plural NZP  CSI- RS  Channel or interference measurement when a subset of resources is set

The following agreements were made at the 3GPP # 90bis meeting.

- NZP CSI-RS resources are set to the UE for channel and interference measurements,

The subset of the set of NZP CSI-RS resources is for channel measurements, and the other subset is for interference measurements.

The network indicates a subset of the NZP CSI-RS resource (s) for channel measurements via the DCI and a subset of the CSI-RS resource (s) for interference measurements.

Whether the DCI indication is dynamic triggering of one or more CSI reporting settings (s) will be discussed, determined,

Whether some CSI-RS resource (s) of the two NZP CSI-RS resource subsets are overlapped will be discussed and determined later.

- If the UE does not have PMI and RI feedback, it is assumed that each port of the channel measurement NZP CSI-RS resource (s) corresponds to the required layer.

This means that the above-mentioned CIMR / PIMR is set as a resource unit. That is, for a set of NZP CSI-RS resources, a subset of one or more NZP CSI-RS resources is set up / signaled and the base station receives a subset of resources actually measured through dynamic signaling, such as DCI, and / It may inform the UE whether each subset of RS resources is for channel measurement or for interference measurement.

A subset of the resources of the consensus set up port-wise channel measurements and port-wise interference measurements for different resources in terms of resources used for actual channel measurement / interference measurements, And so it is obvious that the same technique as the CIMR described in this specification is technically identical. However, since the configuration of each resource is independently set for each resource, the corresponding port-wide NZP CSI-RS-based IMR is set in a (partial) set of resources (for example, a subset of resources is CMR or IMR or DCI (Eg, CSI-RS power, timing behavior (periodic / semi-persistent / non-periodic), period / offset, etc.) that can be independently set for each resource configuration Can be set differently, and ambiguity can occur in channel / interference measurement of the aggregated resources. Therefore, we propose the following method to solve this problem.

The set of parameters for that resource configuration may contain one or more of the following parameters. The parameter list to be applied may be defined in advance or may be set to upper-layer signaling such as RRC.

Timing behavior: eg, acyclic / semi-continuous / periodic

- Periodic / semi-continuous, including period and slot offset

• Bandwidth Part (BWP) index and CSI-RS transmission bandwidth in BWP

● RB-level density

● MR on / off

- Independent setting for time / frequency domain MR

Power indicator (e.g., p_c)

The following is based on a subset of the resources mentioned in the consensus for convenience, but the technique is not limited to NZP CSI-RS based IMR setup / signaling based on a subset of resources. In other words, in the practical application of this technology, it is possible to use setting / signaling for a subset of resources, a set of resources, a resource set, a resource or a port (group) unit. Also, for convenience, a subset of each resource is set for C-port / I-port to be set for port-wise channel measurement / port-wise interference measurement.

Alt 1. Fixed value

When a (sub) set of specific resources is used as a C-port and / or an I-port, the settings that are actually used for each resource are set for some or all of the set of parameters set for each resource configuration Or ignoring the value given in the resource configuration). This scheme is easier to implement because there is no setup overhead, no misalignment on both sides of the base station-terminal, and the UE performs measurements on a particular scheme, since there is no need to provide a separate setup.

The timing behavior of the above parameters can be assumed to be aperiodic. This is because the IMR of the NZP CSI-RS is defined for the MU situation and the channel / interference shown to the UE in the resource is changed dynamically according to time. For similar reasons, the terminal may operate assuming MR on.

The BWP index can be assumed to be the same as the currently active BWP of the UE. This is because, similar to the above, the resource is created taking into account the MU situation, and thus it is desirable that the CSI for the current scheduled or scheduled BWP is reported.

If the NZP CSI-RS resource does not support a large number of ports, reducing the density to reduce the overhead may also be inefficient in terms of channel / interference measurement performance, such as density. Therefore, in such a case, it can be assumed that the density = 1.

For the CSI-RS power, since the resource assumes a manner in which the UE measures the power of the beamformed CSI-RS transmitted by the base station, it is assumed that the corresponding resource has the same power as the data, that is, It can be assumed that it has a power difference.

Alt 2. Configuration-reference resource

When a (sub) set of specific resources is used as a C-port or / and an I-port, the settings that are actually used by each resource are set for some or all of the set of parameters set for each resource configuration Setting is ignored), a subset of resources or set of parameters in the set of resources specified in the set-reference resource in the set of resources. This method can solve the ambiguity described above with a very small number of settings, 1, it provides more flexibility.

The resource to be defined as a configuration-reference resource within a subset of resources or a collection of resources may be defined in advance or may be set to higher-layer signaling such as RRC. In particular, when defined in advance, a resource with the lowest index (within a subset of resources or a set of resources) may be a configuration-based resource. In particular, a set-reference resource is set for a subset of the resources to be actually used, and the set-reference resource can be applied to a set of resources or a subset of selected resources.

Or a setting-reference resource can be determined based on a specific parameter. For example, a resource having the smallest number of ports may be determined as a configuration-reference resource.

Alternatively, the method can be understood as a method of using a specific representative value among a plurality of set values. For example, the smallest value, the largest value, or the median / average value may be used for a plurality of power offset values for a set plurality of resources.

Alt 3. Separated configuration for C-port / I-port case (Separated configuration for C-port / I-port case)

When a (sub) set of specific resources is used as a C-port and / or an I-port, separate settings are defined for some or all of the parameter lists set for each resource configuration, for the settings actually used for each resource. In other words, if the UE is instructed to measure a subset of resources and a subset of each resource is set to C-port or / and I-port, the resources contained in the subset of that resource are set Port / I-port in a subset of resources instead of some or all of the listed parameter lists (ignoring those settings if there are separate settings). This provides greater configuration flexibility than Alt 1, 2 described above.

This setting is given to the terminal in the RRC setting. The CSI report selects one or more subsets, assigns channel / interference measurements for each subset, measures a subset of that resource and calculates / reports the specified CSI.

Similarly, a parameter list for the corresponding C-port and / or I-port may be set as a collection of resources or resource units.

Such a scheme may be implemented in a manner that sets / defines different setting parameter values, in particular a lower / upper limit, between the NZP CSI-RS based IMR and a value that can be set for different types of channel / . In this case, the parameter value set in the NZP CSI-RS based IMR can be interpreted as min (maximum value, set value).

Alt. 4 Individual Signaling

In order to reduce the configuration latency of the parameter list, which is set to upper-layer signaling such as RRC, the BS may perform a signaling such as L2 CE signaling such as MAC CE or a DCI Through L1 signaling, you can set the terminal to actually use the parameter value (ignoring the parameter (s) set in the resource configuration). At this time, the DCI signaling can be transmitted together with the above-mentioned aperiodic RS indication.

If a subset of resources is set / defined / signaled to measure as a generic channel measurement instead of a port-wise channel measurement, then the subset of that resource is not aggregated and only one resource (e.g., the first resource) have. Otherwise, if the same aggregation is used, the above method can be applied equally. However, in this case, general channel measurement and setting / signaling used for port-wise channel measurement can be separated and set / defined.

Alt 5. Do not expect to set different value (s) for multiple resource settings (s)

The terminal may not expect different settings (s) to be set for some or all of the above parameters for resources that are aggregated into a (sub) set of one resource. The base station gives the same settings to all resources for some or all of the parameters for the resources in the (partial) set of corresponding resources, and the terminal also expects the base station to do so. For example, for power offset, RB-level density, and band setting, the terminal may not expect the settings of each resource to be set differently.

In the case of band setting in the above parameter list, a mismatch may occur with the CSI reporting band (i. E., A subset of the subbands of the bandwidth part for CSI reporting). For example, the situation shown in FIG. 9 may be considered.

In particular, if there is no RS to be measured / reported for the band set as the reporting band, CSI can not be measured / reported in that band. Therefore, the following method is further proposed for band setting.

Alt 6. The CSI shall have a common set of reporting bands set in the reporting settings and band settings set for the multiple (aggregated) NZP CSI-RS resource settings (for channel and / or interference measurement) It can be measured / reported for the band to which it belongs.

That is, the UE can measure / report CSI for a band corresponding to the common band in the example of FIG.

With a special case of a subset of the above-mentioned resources, a case containing only a single resource can also be considered. In addition, a configuration unit such as the above-described set of resources, a subset of resources, and the like may be the same as the resource set in the CSI framework set for the CSI report.

The above-described technique can be applied to a plurality of parameter sets in different ways. More specifically, parameter groups may be set and different alternatives may be applied for each parameter group, such as setting some parameters to default values and specifying remaining resources to be reference resources.

The (partial) set of the above-mentioned resources may be given different setting / signaling depending on the DMRS type. More specifically, the number of aggregated ports in a subset of the resources set according to the DMRS type can be set differently. Two types of DMRS can be configured in the NewRat, each of which has the following characteristics.

	DMRS type 1	DMRS type 2
Maximum number of ports	8	12
Maximum number of terminals in MU case	4	4
FDM DMRS resources	2	3
REs in the CDRS-DMRS port group	3	2

Therefore, the maximum number of MU layers depends on the DMRS type set for the UE, and thus, determining the maximum number of C-ports (I-ports) by assuming CIMR / PIMR is used to simulate the actual interference situation It is advantageous. Therefore, the maximum number of ports can be determined as follows.

• The total number of C-ports of aggregated resources in CIMR is 4 ports maximum.

If the subset of resources is set / defined / signaled to be measured as a generic channel measurement instead of a port-wise channel measurement, the port-number limitations described above may not apply. To this end, the base station can separately set up a (partial) set of resources to be used when a (partial) set of specific resources is used for the measurement of the port-wise channel and when it is used for general channel measurement. At this time, the following method can be used.

Alt 1. If the total number of ports of resources contained in a subset of specific resources exceeds 4, the terminal does not expect the subset of resources to be set to C-port.

Alt 2. When the total number of ports of a resource contained in a subset of resources exceeds 4 and a subset of those resources is set as a C-port, only up to 4 ports of the subset of the resources are used as C-ports The rest is not measured.

A. To this end, the aggregated resources of a subset of each resource can be configured to be broken up into 4-port units. For example, a subset of resources with a total of six ports can be configured as a two-port resource, a two-port resource, and a two-port resource, The same setting is not possible.

Alt 3. The total number of ports of a resource contained in a subset of each resource is limited to a maximum of four.

A. This can be applied to a subset of resources to be used as a C-port, even if only the resources to be used as the C-port are set as a subset of the resources in the entire set of resources and the remaining resources are used as the I-port .

B. However, in this case, if the general channel measurement is set instead of the C-port, the operation may be limited due to the maximum number of ports defined.

The total number of aggregated ports (number of C-ports + number of I-ports) in the (partial) set of resources in CIMR is 8 for DMRS type 1 and 12 for DMRS type 2.

For this purpose, the BS can set a subset of different resources according to the DMRS type. To do this, you can use the following method.

Alt 1. Set (partial) set of separate resources according to DMRS type

There is no need to define additional configuration methods in a way that uses the existing configuration methods in a similar way.

Alt 2. Depending on the type of DMRS, only the (maximum) total number of ports mentioned above is used in the (partial) set of established resources and the remainder is not measured.

In this case, since only one setting is set, the setting is simple.

Alt 3. A set of up to 8-total port resources / subset of resources / resource group to be used in common for DMRS type 1 and DMRS type 2, a subset or resource of additional resources used only for DMRS type 2 Set the group separately. The total number of ports in a subset or resource group of these resources may be set to be equal to or less than four.

A. As a subset or resource group configuration of additional resources for each DMRS type 2 configuration, the configuration for DMRS type 1 can be reused as much as possible.

B. In this case, the subset or resource group of the corresponding resource operates in the same manner as the case where the DMRS type 1 is set and the IMR is not set for the corresponding resource.

For the current consensus, a given set of resources can be set to C-port if PMI and RI feedback are not used. For similar situations, the following approach can be considered.

• If the CSI report for that measurement trigger is set to PUCCH reporting, the (partial) set of resources specified by that measurement trigger shall be considered an NZP CSI-RS based IMR.

In this case, only CSIs that require a small amount of computation can be calculated / reported to reduce the CSI overhead. Thus, even if there is no separate configuration / signaling as described above, the measurement is a C-port, i.e., a subset of resources set with channel measurements, and a precoded CSI-RS It is regarded as corresponding to and measured.

● If the measurement trigger is specified as a DL DCI, the (partial) set of resources specified by that measurement trigger is considered to be an NZP CSI-RS based IMR.

When the CSI report is designated as PUCCH report, it is considered to transmit it to the DL DCI. Therefore, the corresponding measurement trigger also needs to be transmitted to the same DL DCI. In other words, if a measurement trigger is specified as a DL DCI, the resource specified by that trigger is an NZP CSI-RS-based IMR and is considered a C-port and an I-port on a per-port basis (depending on configuration / signaling) CSI can be measured.

 In other words, the (partial) set of resources and / or resources designated by the DCI field corresponding to the measurement trigger in the above two schemes can be considered as an NZP CSI-RS based IMR.

In actual applications of the techniques described herein, these techniques may be applied alone or in combination.

10 is a block diagram illustrating components of a transmitting apparatus 10 and a receiving apparatus 20 that perform embodiments of the present invention. The transmitting apparatus 10 and the receiving apparatus 20 may include a transmitter / receiver 13, 23 capable of transmitting or receiving radio signals carrying information and / or data, signals, messages and the like, A memory 12, 22 for storing various information, a transmitter / receiver 13, 23 and a memory 12, 22, so as to control the component, (11, 21) configured to control the memory (12, 22) and / or the transmitter / receiver (13, 23) to perform at least one of the embodiments of the present invention.

The memories 12 and 22 may store a program for processing and controlling the processors 11 and 21, and may temporarily store the input / output information. The memories 12 and 22 can be utilized as buffers. Processors 11 and 21 typically control the overall operation of the various modules within the transmitting or receiving device. In particular, the processors 11 and 21 may perform various control functions to perform the present invention. The processors 11 and 21 may also be referred to as a controller, a microcontroller, a microprocessor, a microcomputer, or the like. The processors 11 and 21 may be implemented by hardware or firmware, software, or a combination thereof. When implementing the present invention using hardware, application specific integrated circuits (ASICs) or digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs field programmable gate arrays) may be provided in the processors 11 and 21. Meanwhile, when the present invention is implemented using firmware or software, firmware or software may be configured to include a module, a procedure, or a function for performing the functions or operations of the present invention. The firmware or software may be contained within the processors 11, 21 or may be stored in the memories 12, 22 and driven by the processors 11,

The processor 11 of the transmission apparatus 10 performs predetermined coding and modulation on signals and / or data scheduled to be transmitted from the scheduler connected to the processor 11 or the processor 11, And transmits it to the transmitter / receiver 13. For example, the processor 11 converts a data stream to be transmitted into K layers through demultiplexing, channel coding, scrambling, modulation, and the like. The encoded data stream is also referred to as a code word and is equivalent to a transport block that is a data block provided by the MAC layer. One transport block (TB) is encoded into one codeword, and each codeword is transmitted to the receiving device in the form of one or more layers. For frequency up-conversion, the transmitter / receiver 13 may comprise an oscillator. Transmitter / receiver 13 may include Nt (where Nt is a positive integer greater than one) transmit antennas.

The signal processing procedure of the receiving apparatus 20 is configured in reverse to the signal processing procedure of the transmitting apparatus 10. [ Under the control of the processor 21, the transmitter / receiver 23 of the receiving device 20 receives the radio signal transmitted by the transmitting device 10. The transmitter / receiver 23 may include Nr receive antennas, and the transmitter / receiver 23 may frequency down-convert each of the signals received through the receive antenna to reconstruct the baseband signal do. Transmitter / receiver 23 may include an oscillator for frequency downconversion. The processor 21 may perform decoding and demodulation of the radio signal received through the reception antenna to recover data that the transmission apparatus 10 originally intended to transmit.

The transmitter / receivers 13, 23 have one or more antennas. The antenna may transmit signals processed by the transmitters / receivers 13 and 23 to the outside, receive radio signals from the outside, and transmit the processed signals to the transmitter / receiver 13 and 23 under the control of the processors 11 and 21 in accordance with an embodiment of the present invention. (13, 23). Antennas are sometimes referred to as antenna ports. Each antenna may correspond to one physical antenna or may be composed of a combination of more than one physical antenna element. The signal transmitted from each antenna can not be further decomposed by the receiving apparatus 20. [ A reference signal (RS) transmitted in response to the antenna defines the antenna viewed from the perspective of the receiving apparatus 20 and indicates whether the channel is a single radio channel from one physical antenna, Enables the receiving device 20 to channel estimate for the antenna regardless of whether it is a composite channel from a plurality of physical antenna elements. That is, the antenna is defined such that a channel carrying a symbol on the antenna can be derived from the channel through which another symbol on the same antenna is transmitted. In the case of a transmitter / receiver supporting a multi-input multi-output (MIMO) function for transmitting and receiving data using a plurality of antennas, it can be connected to two or more antennas.

Although the operation of the above-described proposal or invention has been described in terms of a "terminal" or a "base station", it is to be understood that the invention may be implemented or implemented by a transmitting or receiving device, a (digital signal) processor, .

In addition, as another aspect of the present invention, the operation of the above-described proposal or invention may be achieved by a computer (a generic concept including a system on chip (SoC) or (micro) processor, etc.) Or may be provided in the form of a computer-readable storage medium or a computer program product storing or containing the code, and the scope of the present invention is not limited to storing or storing the code or the code, Readable storage medium or computer program product.

The term " terminal " is a generic term used interchangeably with a device having mobility such as a mobile station (MS), a user equipment (UE) , eNB (evolved NodeB), ng-eNB (next generation eNode B), gNB (next generation NodeB), and the like.

In the embodiments of the present invention, the UE or the UE operates as the transmitting apparatus 10 in the uplink and operates as the receiving apparatus 20 in the downlink. In the embodiments of the present invention, the base station, the eNB, the ng-eNB, or the gNB operate as the receiving apparatus 20 in the uplink and the transmitting apparatus 10 in the downlink.

The transmitting apparatus and / or the receiving apparatus may perform at least one of the embodiments of the present invention described above or a combination of two or more embodiments.

As one of the combinations of these proposals, in an interference measurement in a wireless communication system according to another embodiment of the present invention, there is provided a terminal comprising: a transmitter and a receiver; And a processor configured to control the transmitter and the receiver, wherein the port-wide channel and the interference measurement resource correspond to independent interference assumptions for each port, And a terminal-group specific channel and interference measurement resources, and to measure channel and interference for each port in the port-wise channel and the interference measurement resource, and report the measurement result.

In addition, the UE-group specific channel and interference measurement resources may be used to correct a previously reported channel quality indicator (CQI).

Also, the UE-group specific channel and interference measurement resources may be set semi-persistently and may be enabled or disabled by signaling from the network.

In addition, if the UE is not scheduled for UL transmission or DL reception, the processor can perform the measurement by assuming that all the ports of the UE-group specific channel and the interference measurement resource are ports through which the interference signal is transmitted .

In addition, the settings related to the UE-group specific channel and interference measurement resources may include a port for channel measurement and an index or number of ports for interference measurement and may be associated with the UE- The setting may be included in an aperiodic reference signal indication for the resource.

In addition, the port of the UE-group specific channel and the interference measurement resource corresponds one-to-one with the demodulation reference signal port, the demodulation reference signal port for the UE corresponds to a port for channel measurement, It can be used as a port.

In addition, the settings related to the UE-group specific channel and interference measurement resources may include information on the number of co-scheduled multi-user (MU) layers or the total number of MU layers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing description of the preferred embodiments of the invention disclosed herein has been presented to enable any person skilled in the art to make and use the present invention. While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims. Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The present invention can be used in a wireless communication device such as a terminal, a relay, a base station, and the like.

Claims (15)

1. A method of channel measurement and reporting using a port-wise channel and an interference measurement resource in a wireless communication system, the method comprising:

   Receiving a setting related to a port-wise channel and an interference measurement resource;

   The port-wise channel and interference measurement resources correspond to independent interference assumptions for each port, and include terminal-group specific channel and interference measurement resources, and

   Measuring the channel and interference for each port in the port-wise channel and the interference measurement resource, and reporting the measurement result.
2. The method according to claim 1,

   Wherein the terminal-group specific channel and interference measurement resources are for correcting a previously reported channel quality indicator (CQI).
3. The method according to claim 1,

   Wherein the terminal-group specific channel and interference measurement resources are semi-persistently set and activated or deactivated by signaling from the network.
4. The method of claim 1, wherein if the UE is not scheduled for UL transmission or DL reception,

   And performing the measurement by assuming that all the ports of the UE-group specific channel and the interference measurement resource are ports through which the interference signal is transmitted.
5. The method according to claim 1,

   The settings related to the UE-group specific channel and interference measurement resources include a port for channel measurement and an index or number of ports for interference measurement,

   Wherein settings relating to the UE-group specific channel and interference measurement resources are included in an aperiodic reference signal indication for the resource.
6. The method according to claim 1,

   The port of the UE-group specific channel and the interference measurement resource correspond to the demodulation reference signal port on a one-to-one basis, the demodulation reference signal port for the UE corresponds to a port for channel measurement and the other port corresponds to a port for interference measurement ≪ / RTI >
7. The method according to claim 1,

   Wherein the setting related to the UE-group specific channel and interference measurement resources includes information on a co-scheduled multi-user (MU) layer number or an entire MU layer number.
8. A terminal for performing channel measurement in a wireless communication system,

   Transmitter and receiver; And

   And a processor configured to control the transmitter and the receiver,

   The processor comprising:

   Receiving a setting related to the port-wise channel and the interference measurement resource,

   Wherein the port-wise channel and interference measurement resources correspond to independent interference assumptions for each port and include terminal-group specific channel and interference measurement resources,

   And measures the channel and interference for each port in the port-wise channel and the interference measurement resource, and reports the measurement result.
9. 9. The method of claim 8,

   Wherein the terminal-group specific channel and interference measurement resources are for correcting a previously reported channel quality indicator (CQI).
10. 9. The method of claim 8,

    Wherein the terminal-group specific channel and interference measurement resources are semi-persistently set and activated or deactivated by signaling from the network.
11. 9. The method of claim 8, wherein if the UE is not scheduled for UL transmission or DL reception, the processor assumes all ports of the UE-group specific channel and interference measurement resources as the port through which the interfering signal is transmitted, The terminal being capable of performing a predetermined function.
12. 9. The method of claim 8,

    The settings related to the UE-group specific channel and interference measurement resources include a port for channel measurement and an index or number of ports for interference measurement,

    Wherein settings relating to the UE-group specific channel and interference measurement resources are included in an aperiodic reference signal indication for the resource.
13. 9. The method of claim 8,

    The port of the UE-group specific channel and the interference measurement resource correspond to the demodulation reference signal port on a one-to-one basis, the demodulation reference signal port for the UE corresponds to a port for channel measurement and the other port corresponds to a port for interference measurement Characterized in that the terminal is used.
14. 9. The method of claim 8,

    Wherein the setting related to the UE-group specific channel and the interference measurement resource includes information on the number of co-scheduled multi-user (MU) layers or the total number of MU layers.
15. 22. A computer program code for a computer program code, the computer program code being executable by a processor of a communication device, the communication device comprising:

    Receiving a setting related to the port-wise channel and the interference measurement resource,

    Wherein the port-wise channel and interference measurement resources correspond to independent interference assumptions for each port and include terminal-group specific channel and interference measurement resources,

    And to measure channel and interference for each port in the port-wise channel and the interference measurement resource, and to report the measurement result.

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