WO2020032477A1

WO2020032477A1 - Method for transmitting/receiving downlink signal between terminal and base station in wireless communication system, and device for supporting same

Info

Publication number: WO2020032477A1
Application number: PCT/KR2019/009612
Authority: WO
Inventors: 이길봄; 김규석; 강지원
Original assignee: 엘지전자 주식회사
Priority date: 2018-08-10
Filing date: 2019-08-01
Publication date: 2020-02-13

Abstract

Disclosed are a method for transmitting/receiving a downlink signal between a terminal and a base station in a wireless communication system, and a device for supporting same. According to one embodiment applicable to the present invention, when the terminal receives, from the base station, downlink control information (DCI) including a plurality of transmission configuration indication (TCI) states, the terminal can receive a first physical downlink shared channel (PDSCH) on the basis of the assumption that the position of an additional demodulation reference signal (DMRS) for the first PDSCH and the position of an additional DMRS for a second PDSCH, both of which are scheduled by the DCI, are the same.

Description

Method for transmitting and receiving a downlink signal between a terminal and a base station in a wireless communication system and an apparatus supporting the same

The following description relates to a wireless communication system, and a method for transmitting and receiving a downlink signal between a terminal and a base station in a wireless communication system and an apparatus supporting the same.

Wireless access systems are widely deployed to provide various kinds of communication services such as voice and data. In general, a wireless access system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency (SC-FDMA). division multiple access) system.

In addition, as more communication devices require larger communication capacities, an improved mobile broadband communication technology is introduced as compared to the existing radio access technology (RAT). In addition, a communication system considering a service / UE that is sensitive to reliability and latency as well as Massive MTC (Machine Type Communications), which provides various services anytime and anywhere by connecting a plurality of devices and objects, is introduced.

As such, mobile broadband communication, massive MTC, and ultra-reliable and low latency communication (URLLC) are introduced. In particular, as a method of transmitting and receiving signals through various frequency bands is considered, various configurations of a phase tracking reference signal (PT-RS) for estimating phase noise between a terminal and a base station in various frequency bands are discussed. It is becoming.

In addition, the present invention may be related to the following technical configurations.

<인공 지능(AI: Artificial Intelligence)>Artificial Intelligence (AI)

Artificial intelligence refers to the field of researching artificial intelligence or the methodology that can produce it, and machine learning refers to the field of researching methodologies to define and solve various problems dealt with in the field of artificial intelligence. do. Machine learning is defined as an algorithm that improves the performance of a task through a consistent experience with a task.

Artificial Neural Network (ANN) is a model used in machine learning, and may refer to an overall problem-solving model composed of artificial neurons (nodes) networked by synapses. The artificial neural network may be defined by a connection pattern between neurons of different layers, a learning process of updating model parameters, and an activation function generating an output value.

The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer contains one or more neurons, and the artificial neural network may include synapses that connect neurons to neurons. In an artificial neural network, each neuron may output a function value of an active function for input signals, weights, and deflections input through a synapse.

The model parameter refers to a parameter determined through learning and includes weights of synaptic connections and deflection of neurons. In addition, the hyperparameter means a parameter to be set before learning in the machine learning algorithm, and includes a learning rate, the number of iterations, a mini batch size, an initialization function, and the like.

The purpose of learning artificial neural networks can be seen as determining model parameters that minimize the loss function. The loss function can be used as an index for determining an optimal model parameter in the learning process of an artificial neural network.

Machine learning can be categorized into supervised learning, unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of learning artificial neural networks with a given label for training data, and a label indicates a correct answer (or result value) that the artificial neural network must infer when the training data is input to the artificial neural network. Can mean. Unsupervised learning may refer to a method of training artificial neural networks in a state where a label for training data is not given. Reinforcement learning can mean a learning method that allows an agent defined in an environment to learn to choose an action or sequence of actions that maximizes cumulative reward in each state.

Machine learning, which is implemented as a deep neural network (DNN) including a plurality of hidden layers among artificial neural networks, is called deep learning (Deep Learning), which is part of machine learning. Hereinafter, machine learning is used to mean deep learning.

<로봇(Robot)><Robot>

A robot can mean a machine that automatically handles or operates a given task by its own ability. In particular, a robot having a function of recognizing the environment, judging itself, and performing an operation may be referred to as an intelligent robot.

Robots can be classified into industrial, medical, household, military, etc. according to the purpose or field of use.

The robot may include a driving unit including an actuator or a motor to perform various physical operations such as moving a robot joint. In addition, the movable robot includes a wheel, a brake, a propeller, and the like in the driving unit, and can travel on the ground or fly in the air through the driving unit.

<자율 주행(Self-Driving, Autonomous-Driving)>Self-Driving, Autonomous-Driving

Autonomous driving means a technology that drives by itself, and an autonomous vehicle means a vehicle that runs without a user's manipulation or with minimal manipulation of a user.

For example, for autonomous driving, the technology of maintaining a driving lane, the technology of automatically adjusting speed such as adaptive cruise control, the technology of automatically driving along a predetermined route, the technology of automatically setting a route when a destination is set, etc. All of these may be included.

The vehicle includes a vehicle having only an internal combustion engine, a hybrid vehicle having both an internal combustion engine and an electric motor together, and an electric vehicle having only an electric motor, and may include not only automobiles but also trains and motorcycles.

In this case, the autonomous vehicle may be viewed as a robot having an autonomous driving function.

<확장 현실(XR: eXtended Reality)>EXtended Reality (XR)

Extended reality collectively refers to virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology provides real world objects and backgrounds only in CG images, AR technology provides virtual CG images on real objects images, and MR technology mixes and combines virtual objects in the real world. Graphic technology.

MR technology is similar to AR technology in that it shows both real and virtual objects. However, in AR technology, virtual objects are used as complementary objects to real objects, whereas in MR technology, virtual objects and real objects are used in an equivalent nature.

XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phone, tablet PC, laptop, desktop, TV, digital signage, etc. It can be called.

1 illustrates an AI device 100 according to an embodiment of the present invention.

The AI device 100 includes a TV, a projector, a mobile phone, a smartphone, a desktop computer, a notebook computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a tablet PC, a wearable device, and a set-top box (STB). ), A DMB receiver, a radio, a washing machine, a refrigerator, a desktop computer, a digital signage, a robot, a vehicle, or the like.

Referring to FIG. 1, the terminal 100 includes a communication unit 110, an input unit 120, a running processor 130, a sensing unit 140, an output unit 150, a memory 170, a processor 180, and the like. It may include.

The communicator 110 may transmit / receive data to / from external devices such as the other AI devices 100a to 100e or the AI server 200 using wired or wireless communication technology. For example, the communicator 110 may transmit / receive sensor information, a user input, a learning model, a control signal, and the like with external devices.

In this case, the communication technology used by the communication unit 110 may include Global System for Mobile Communication (GSM), Code Division Multi Access (CDMA), Long Term Evolution (LTE), 5G, Wireless LAN (WLAN), and Wireless-Fidelity (Wi-Fi). ), Bluetooth (Bluetooth®), RFID (Radio Frequency Identification), Infrared Data Association (IrDA), ZigBee, Near Field Communication (NFC), and the like.

The input unit 120 may acquire various types of data.

In this case, the input unit 120 may include a camera for inputting an image signal, a microphone for receiving an audio signal, a user input unit for receiving information from a user, and the like. Here, a signal obtained from the camera or microphone may be referred to as sensing data or sensor information by treating the camera or microphone as a sensor.

The input unit 120 may acquire input data to be used when acquiring an output using training data and a training model for model training. The input unit 120 may obtain raw input data, and in this case, the processor 180 or the running processor 130 may extract input feature points as preprocessing on the input data.

The running processor 130 may train a model composed of artificial neural networks using the training data. Here, the learned artificial neural network may be referred to as a learning model. The learning model may be used to infer result values for new input data other than the training data, and the inferred values may be used as a basis for judgment to perform an operation.

In this case, the running processor 130 may perform AI processing together with the running processor 240 of the AI server 200.

In this case, the running processor 130 may include a memory integrated with or implemented in the AI device 100. Alternatively, the running processor 130 may be implemented using the memory 170, an external memory directly coupled to the AI device 100, or a memory held in the external device.

The sensing unit 140 may acquire at least one of internal information of the AI device 100, surrounding environment information of the AI device 100, and user information using various sensors.

In this case, the sensors included in the sensing unit 140 include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint sensor, an ultrasonic sensor, an optical sensor, a microphone, and a li. , Radar and so on.

The output unit 150 may generate an output related to visual, auditory, or tactile.

In this case, the output unit 150 may include a display unit for outputting visual information, a speaker for outputting auditory information, and a haptic module for outputting tactile information.

The memory 170 may store data supporting various functions of the AI device 100. For example, the memory 170 may store input data, training data, training model, training history, and the like acquired by the input unit 120.

The processor 180 may determine at least one executable operation of the AI device 100 based on the information determined or generated using the data analysis algorithm or the machine learning algorithm. In addition, the processor 180 may control the components of the AI device 100 to perform a determined operation.

To this end, the processor 180 may request, search, receive, or utilize data of the running processor 130 or the memory 170, and may perform an operation predicted or determined to be preferable among the at least one executable operation. The components of the AI device 100 may be controlled to execute.

In this case, when the external device needs to be linked to perform the determined operation, the processor 180 may generate a control signal for controlling the corresponding external device and transmit the generated control signal to the corresponding external device.

The processor 180 may obtain intention information about the user input, and determine the user's requirements based on the obtained intention information.

In this case, the processor 180 uses at least one of a speech to text (STT) engine for converting a voice input into a string or a natural language processing (NLP) engine for obtaining intention information of a natural language. Intent information corresponding to the input can be obtained.

In this case, at least one or more of the STT engine or the NLP engine may be configured as an artificial neural network, at least partly learned according to a machine learning algorithm. At least one of the STT engine or the NLP engine may be learned by the running processor 130, may be learned by the running processor 240 of the AI server 200, or may be learned by distributed processing thereof. It may be.

The processor 180 collects history information including operation contents of the AI device 100 or feedback of a user about the operation, and stores the information in the memory 170 or the running processor 130, or the AI server 200. Can transmit to external device. The collected historical information can be used to update the learning model.

The processor 180 may control at least some of the components of the AI device 100 to drive an application program stored in the memory 170. In addition, the processor 180 may operate by combining two or more of the components included in the AI device 100 to drive the application program.

2 illustrates an AI server 200 according to an embodiment of the present invention.

Referring to FIG. 2, the AI server 200 may refer to an apparatus for learning an artificial neural network using a machine learning algorithm or using an learned artificial neural network. Here, the AI server 200 may be composed of a plurality of servers to perform distributed processing, or may be defined as a 5G network. In this case, the AI server 200 may be included as a part of the AI device 100 to perform at least some of the AI processing together.

The AI server 200 may include a communication unit 210, a memory 230, a running processor 240, a processor 260, and the like.

The communication unit 210 may transmit / receive data with an external device such as the AI device 100.

The memory 230 may include a model storage unit 231. The model storage unit 231 may store a trained model or a trained model (or artificial neural network 231a) through the running processor 240.

The running processor 240 may train the artificial neural network 231a using the training data. The learning model may be used while mounted in the AI server 200 of the artificial neural network, or may be mounted and used in an external device such as the AI device 100.

The learning model can be implemented in hardware, software or a combination of hardware and software. When some or all of the learning model is implemented in software, one or more instructions constituting the learning model may be stored in the memory 230.

The processor 260 may infer a result value with respect to the new input data using the learning model, and generate a response or control command based on the inferred result value.

3 shows an AI system 1 according to an embodiment of the present invention.

Referring to FIG. 3, the AI system 1 may include at least one of an AI server 200, a robot 100a, an autonomous vehicle 100b, an XR device 100c, a smartphone 100d, or a home appliance 100e. This cloud network 10 is connected. Here, the robot 100a to which the AI technology is applied, the autonomous vehicle 100b, the XR device 100c, the smartphone 100d or the home appliance 100e may be referred to as the AI devices 100a to 100e.

The cloud network 10 may refer to a network that forms part of the cloud computing infrastructure or exists in the cloud computing infrastructure. Here, the cloud network 10 may be configured using a 3G network, 4G or Long Term Evolution (LTE) network or a 5G network.

That is, the devices 100a to 100e and 200 constituting the AI system 1 may be connected to each other through the cloud network 10. In particular, the devices 100a to 100e and 200 may communicate with each other through the base station, but may communicate with each other directly without passing through the base station.

The AI server 200 may include a server that performs AI processing and a server that performs operations on big data.

The AI server 200 includes at least one or more of the AI devices constituting the AI system 1, such as a robot 100a, an autonomous vehicle 100b, an XR device 100c, a smartphone 100d, or a home appliance 100e. Connected via the cloud network 10, the AI processing of the connected AI devices 100a to 100e may help at least a part.

In this case, the AI server 200 may train the artificial neural network according to the machine learning algorithm on behalf of the AI devices 100a to 100e and directly store the learning model or transmit the training model to the AI devices 100a to 100e.

At this time, the AI server 200 receives input data from the AI devices 100a to 100e, infers a result value with respect to the received input data using a learning model, and generates a response or control command based on the inferred result value. Can be generated and transmitted to the AI device (100a to 100e).

Alternatively, the AI devices 100a to 100e may infer a result value from input data using a direct learning model and generate a response or control command based on the inferred result value.

Hereinafter, various embodiments of the AI devices 100a to 100e to which the above-described technology is applied will be described. Here, the AI devices 100a to 100e illustrated in FIG. 3 may be viewed as specific embodiments of the AI device 100 illustrated in FIG. 1.

<AI+로봇><AI + robot>

The robot 100a may be applied to an AI technology, and may be implemented as a guide robot, a transport robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, or the like.

The robot 100a may include a robot control module for controlling an operation, and the robot control module may refer to a software module or a chip implemented in hardware.

The robot 100a acquires state information of the robot 100a by using sensor information obtained from various kinds of sensors, detects (recognizes) the surrounding environment and an object, generates map data, moves paths and travels. You can decide on a plan, determine a response to a user interaction, or determine an action.

Here, the robot 100a may use sensor information obtained from at least one sensor among a rider, a radar, and a camera to determine a movement route and a travel plan.

The robot 100a may perform the above operations by using a learning model composed of at least one artificial neural network. For example, the robot 100a may recognize the surrounding environment and the object using the learning model, and determine the operation using the recognized surrounding environment information or the object information. Here, the learning model may be directly learned by the robot 100a or may be learned by an external device such as the AI server 200.

In this case, the robot 100a may perform an operation by generating a result using a direct learning model, but transmits sensor information to an external device such as the AI server 200 and receives the result generated accordingly to perform an operation. You may.

The robot 100a determines a movement route and a travel plan by using at least one of map data, object information detected from sensor information, or object information obtained from an external device, and controls the driving unit to determine the movement path and the travel plan. Accordingly, the robot 100a may be driven.

The map data may include object identification information for various objects arranged in a space in which the robot 100a moves. For example, the map data may include object identification information about fixed objects such as walls and doors and movable objects such as flower pots and desks. The object identification information may include a name, type, distance, location, and the like.

In addition, the robot 100a may control the driving unit based on the control / interaction of the user, thereby performing an operation or driving. In this case, the robot 100a may acquire the intention information of the interaction according to the user's motion or voice utterance, and determine the response based on the obtained intention information to perform the operation.

<AI+자율주행><AI + autonomous driving>

The autonomous vehicle 100b may be implemented by an AI technology and implemented as a mobile robot, a vehicle, an unmanned aerial vehicle, or the like.

The autonomous vehicle 100b may include an autonomous driving control module for controlling the autonomous driving function, and the autonomous driving control module may refer to a software module or a chip implemented in hardware. The autonomous driving control module may be included inside as a configuration of the autonomous driving vehicle 100b, but may be configured as a separate hardware and connected to the outside of the autonomous driving vehicle 100b.

The autonomous vehicle 100b obtains state information of the autonomous vehicle 100b by using sensor information obtained from various types of sensors, detects (recognizes) an environment and an object, generates map data, A travel route and a travel plan can be determined, or an action can be determined.

Here, the autonomous vehicle 100b may use sensor information acquired from at least one sensor among a lidar, a radar, and a camera, similarly to the robot 100a, to determine a movement route and a travel plan.

In particular, the autonomous vehicle 100b may receive or recognize sensor information from external devices or receive information directly recognized from external devices. .

The autonomous vehicle 100b may perform the above operations by using a learning model composed of at least one artificial neural network. For example, the autonomous vehicle 100b may recognize a surrounding environment and an object using a learning model, and determine a driving line using the recognized surrounding environment information or object information. Here, the learning model may be learned directly from the autonomous vehicle 100b or may be learned from an external device such as the AI server 200.

In this case, the autonomous vehicle 100b may perform an operation by generating a result using a direct learning model, but transmits sensor information to an external device such as the AI server 200 and receives the result generated accordingly. You can also do

The autonomous vehicle 100b determines a moving route and a driving plan by using at least one of map data, object information detected from sensor information, or object information obtained from an external device, and controls the driving unit to determine the moving route and the driving plan. According to the plan, the autonomous vehicle 100b can be driven.

The map data may include object identification information for various objects arranged in a space (eg, a road) on which the autonomous vehicle 100b travels. For example, the map data may include object identification information about fixed objects such as street lights, rocks, buildings, and movable objects such as vehicles and pedestrians. The object identification information may include a name, type, distance, location, and the like.

In addition, the autonomous vehicle 100b may perform an operation or drive by controlling the driving unit based on the user's control / interaction. In this case, the autonomous vehicle 100b may acquire the intention information of the interaction according to the user's motion or voice utterance, and determine the response based on the obtained intention information to perform the operation.

<AI+XR><AI + XR>

AI technology is applied to the XR device 100c, and a head-mount display (HMD), a head-up display (HUD) provided in a vehicle, a television, a mobile phone, a smartphone, a computer, a wearable device, a home appliance, and a digital signage It may be implemented as a vehicle, a fixed robot or a mobile robot.

The XR apparatus 100c analyzes three-dimensional point cloud data or image data acquired through various sensors or from an external device to generate location data and attribute data for three-dimensional points, thereby providing information on the surrounding space or reality object. It can obtain and render XR object to output. For example, the XR apparatus 100c may output an XR object including additional information about the recognized object in correspondence with the recognized object.

The XR apparatus 100c may perform the above-described operations using a learning model composed of at least one artificial neural network. For example, the XR apparatus 100c may recognize a reality object in 3D point cloud data or image data using a learning model, and may provide information corresponding to the recognized reality object. Here, the learning model may be learned directly from the XR device 100c or learned from an external device such as the AI server 200.

In this case, the XR apparatus 100c may perform an operation by generating a result using a direct learning model, but transmits sensor information to an external device such as the AI server 200 and receives the result generated accordingly. It can also be done.

<AI+로봇+자율주행><AI + Robot + Autonomous Driving>

The robot 100a may be implemented using an AI technology and an autonomous driving technology, such as a guide robot, a transport robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, or the like.

The robot 100a to which the AI technology and the autonomous driving technology are applied may mean a robot itself having an autonomous driving function, a robot 100a interacting with the autonomous vehicle 100b, and the like.

The robot 100a having an autonomous driving function may collectively move devices according to a given copper line or determine a copper line by itself without controlling the user.

The robot 100a and the autonomous vehicle 100b having the autonomous driving function may use a common sensing method to determine one or more of a movement route or a driving plan. For example, the robot 100a and the autonomous vehicle 100b having the autonomous driving function may determine one or more of the movement route or the driving plan by using information sensed through the lidar, the radar, and the camera.

The robot 100a, which interacts with the autonomous vehicle 100b, is present separately from the autonomous vehicle 100b and is linked to the autonomous driving function inside or outside the autonomous vehicle 100b, or the autonomous vehicle 100b. ) May perform an operation associated with the user who boarded.

At this time, the robot 100a interacting with the autonomous vehicle 100b acquires sensor information on behalf of the autonomous vehicle 100b and provides the sensor information to the autonomous vehicle 100b or obtains sensor information, By generating object information and providing the object information to the autonomous vehicle 100b, the autonomous vehicle function of the autonomous vehicle 100b can be controlled or assisted.

Alternatively, the robot 100a interacting with the autonomous vehicle 100b may monitor a user in the autonomous vehicle 100b or control a function of the autonomous vehicle 100b through interaction with the user. . For example, when it is determined that the driver is in a drowsy state, the robot 100a may activate the autonomous driving function of the autonomous vehicle 100b or assist the control of the driver of the autonomous vehicle 100b. Here, the function of the autonomous vehicle 100b controlled by the robot 100a may include not only an autonomous vehicle function but also a function provided by a navigation system or an audio system provided inside the autonomous vehicle 100b.

Alternatively, the robot 100a interacting with the autonomous vehicle 100b may provide information or assist a function to the autonomous vehicle 100b outside the autonomous vehicle 100b. For example, the robot 100a may provide traffic information including signal information to the autonomous vehicle 100b, such as a smart signal light, or may interact with the autonomous vehicle 100b, such as an automatic electric charger of an electric vehicle. You can also automatically connect an electric charger to the charging port.

<AI+로봇+XR><AI + robot + XR>

The robot 100a may be applied to an AI technology and an XR technology, and may be implemented as a guide robot, a transport robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, a drone, or the like.

The robot 100a to which the XR technology is applied may mean a robot that is the object of control / interaction in the XR image. In this case, the robot 100a may be distinguished from the XR apparatus 100c and interlocked with each other.

When the robot 100a that is the object of control / interaction in the XR image acquires sensor information from sensors including a camera, the robot 100a or the XR apparatus 100c generates an XR image based on the sensor information. In addition, the XR apparatus 100c may output the generated XR image. The robot 100a may operate based on a control signal input through the XR apparatus 100c or user interaction.

For example, the user may check an XR image corresponding to the viewpoint of the robot 100a that is remotely linked through an external device such as the XR device 100c, and may adjust the autonomous driving path of the robot 100a through interaction. You can control the movement or driving, or check the information of the surrounding objects.

<AI+자율주행+XR><AI + Autonomous driving + XR>

The autonomous vehicle 100b may be implemented by an AI technology and an XR technology, such as a mobile robot, a vehicle, an unmanned aerial vehicle, and the like.

The autonomous vehicle 100b to which the XR technology is applied may mean an autonomous vehicle having a means for providing an XR image, or an autonomous vehicle that is the object of control / interaction in the XR image. In particular, the autonomous vehicle 100b, which is the object of control / interaction in the XR image, is distinguished from the XR apparatus 100c and may be linked with each other.

The autonomous vehicle 100b having means for providing an XR image may acquire sensor information from sensors including a camera and output an XR image generated based on the obtained sensor information. For example, the autonomous vehicle 100b may provide a passenger with an XR object corresponding to a real object or an object in a screen by outputting an XR image with a HUD.

In this case, when the XR object is output to the HUD, at least a part of the XR object may be output to overlap the actual object to which the occupant's eyes are directed. On the other hand, when the XR object is output on the display provided inside the autonomous vehicle 100b, at least a portion of the XR object may be output to overlap the object in the screen. For example, the autonomous vehicle 100b may output XR objects corresponding to objects such as a road, another vehicle, a traffic light, a traffic sign, a motorcycle, a pedestrian, a building, and the like.

When the autonomous vehicle 100b that is the object of control / interaction in the XR image acquires sensor information from sensors including a camera, the autonomous vehicle 100b or the XR apparatus 100c may be based on the sensor information. The XR image may be generated, and the XR apparatus 100c may output the generated XR image. In addition, the autonomous vehicle 100b may operate based on a user's interaction or a control signal input through an external device such as the XR apparatus 100c.

An object of the present invention is to provide a method for transmitting and receiving a downlink signal between a terminal and a base station in a wireless communication system and apparatuses for supporting the same.

Technical objects to be achieved in the present invention are not limited to the above-mentioned matters, and other technical problems not mentioned above are provided to those skilled in the art from the embodiments of the present invention to be described below. May be considered.

The present invention provides a method and apparatus for transmitting and receiving a downlink signal between a terminal and a base station in a wireless communication system.

In one aspect of the present invention, a method for receiving a downlink signal by a terminal in a wireless communication system, comprising: (i) scheduling at least one physical downlink shared channel (PDSCH), and (ii) a plurality of transmission setup instructions Receive Downlink Control Information (DCI) including Configuration Indication (TCI) states, wherein one TCI state is associated with one reference signal (RS) set; And assuming that an additional demodulation reference signal (DMRS) location for a first PDSCH scheduled by the DCI and an additional DMRS location for a second PDSCH are the same. A method for receiving a downlink signal of a terminal is included.

In the present invention, the additional DMRS location for the first PDSCH may include one or more DMRS symbols except for the front-loaded DMRS symbol during the symbol period of the first PDSCH.

In this case, the front-loaded DMRS symbol during the symbol period of the first PDSCH may include one or two DMRS symbols.

In addition, the method for receiving a downlink signal of the terminal according to the present invention may further include receiving the second PDSCH. In this case, the second PDSCH may be scheduled by the DCI or another DCI.

In the present invention, based on the DCI including the plurality of TCI states, the terminal may recognize that the first PDSCH and the second PDSCH are scheduled for the terminal. In this case, the first PDSCH and the second PDSCH may overlap all or part of the time domain.

Or, based on the DCI includes the plurality of TCI states, the UE is based on the non-coherent joint transmission (NC-JT) mode the first PDSCH and the second PDSCH Can be recognized.

Based on the DCI including the plurality of TCI states, DMRS port information related to the DCI may be obtained based on a table configured for the NC-JT mode. In other words, the terminal according to the present invention may obtain DMRS port information related to the DCI based on a table configured for the NC-JT mode, based on the DCI including the plurality of TCI states.

In the present invention, the DCI may include (i) DMRS information for the first PDSCH, and (2) DMRS information for the second PDSCH.

In this case, the DMRS information may include at least one of the following information.

Number of Code Division Multiplexing (CDM) groups for the corresponding PDSCH.

A rank for the corresponding PDSCH

A combination of DMRS port numbers for the corresponding PDSCH

Number of front-loaded DMRS symbols for the corresponding PDSCH

RS set associated with DMRS for the corresponding PDSCH

In the present invention, the terminal is based on a combination of (i) a combination of DMRS port numbers for the first PDSCH and (ii) a maximum DMRS port number for the second PDSCH, obtained from the DCI. The PDSCH may be received.

In this case, the combination of the maximum DMRS port numbers for the second PDSCH may be configured in a nested structure (eg, the combination of the first maximum DMRS port numbers corresponding to the rank M is the rank M). Is set to include a combination of a second maximum DMRS port number corresponding to a smaller rank N, where M and N are natural numbers).

In this case, the combination of the maximum DMRS port number for the second PDSCH is such that the combination of the third maximum DMRS port number corresponding to rank 1 is the smallest DMRS in the corresponding Code Division Multiplexing (CDM) group. It may be set to include a port number.

In the present invention, based on one or more DMRS port numbers for the first PDSCH indicated by the DCI included in a specific Code Division Multiplexing (CDM) group, the terminal is configured to receive the plurality of TCI states. The first PDSCH may be received using quasi co located (QCL) information derived from an RS set associated with one TCI state.

In the above-described configurations, the first PDSCH and the second PDSCH may overlap all or part of the time domain.

In another aspect of the present invention, a terminal for receiving a downlink signal in a wireless communication system, the terminal comprising: at least one radio frequency (RF) module; At least one processor; And at least one memory operatively coupled to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a particular operation, the specific operation comprising: (i ) Schedule one or more physical downlink shared channel (PDSCH), and (ii) receive downlink control information (DCI) including a plurality of Transmission Configuration Indication (TCI) states, wherein one TCI state Associated with one reference signal (RS) set; And assuming that an additional demodulation reference signal (DMRS) location for a first PDSCH scheduled by the DCI and an additional DMRS location for a second PDSCH are the same. It proposes a terminal that includes.

The terminal may communicate with at least one of a mobile terminal, a network, and an autonomous vehicle other than the vehicle including the terminal.

In still another aspect of the present invention, a base station for transmitting a downlink signal in a wireless communication system, the base station comprising: at least one radio frequency (RF) module; At least one processor; And at least one memory operatively coupled to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a particular operation, the specific operation comprising: (i) scheduling one or more physical downlink shared channel (PDSCH), and (ii) transmitting downlink control information (DCI) including a plurality of Transmission Configuration Indication (TCI) states, wherein The TCI state is associated with one reference signal (RS) set; And one or more terminals including the terminal on the basis of an additional demodulation reference signal (DMRS) position for a first PDSCH scheduled by the DCI and an additional DMRS position for a second PDSCH. The present invention proposes a base station comprising transmitting the first PDSCH and the second PDSCH.

Here, based on the first PDSCH is transmitted through a first TRP (Transmission and Reception Point), the second PDSCH is transmitted through a second TRP, at least one first DMRS port number for the first PDSCH and One or more second DMRS port numbers for the second PDSCH may be included in different Code Division Multiplexing (CDM) group numbers.

The above-described aspects of the present invention are merely some of the preferred embodiments of the present invention, and various embodiments reflecting the technical features of the present invention will be described in detail by those skilled in the art. Based on the description, it can be derived and understood.

According to embodiments of the present invention has the following effects.

According to the present invention, based on the fact that the additional DMRS position for the first PDSCH scheduled to the terminal and the additional DMRS position for the second PDSCH (scheduled to the terminal or another terminal) are the same, the terminal selects the first PDSCH. Receive / acquire with high reliability.

In addition, according to the present invention, the base station may provide DMRS information associated with a plurality of PDSCHs to the terminal, the terminal can reduce the complexity due to the blind detection for the DMRS port, etc. based on the information and due to the wrong detection The decrease in performance can be prevented.

The effects obtainable in the embodiments of the present invention are not limited to the above-mentioned effects, and other effects not mentioned above are common knowledge in the technical field to which the present invention pertains from the following description of the embodiments of the present invention. Can be clearly derived and understood by those who have In other words, unintended effects of practicing the present invention may also be derived by those skilled in the art from the embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are provided to facilitate understanding of the present invention, and provide embodiments of the present invention together with the detailed description. However, the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment. Reference numerals in each drawing refer to structural elements.

1 illustrates an AI device according to an embodiment of the present invention.

2 illustrates an AI server according to an embodiment of the present invention.

3 illustrates an AI system according to an embodiment of the present invention.

4 is a diagram illustrating a physical channel and a signal transmission method using the same.

5 is a diagram illustrating a structure of a radio frame based on an NR system to which embodiments of the present invention are applicable.

6 illustrates a slot structure based on an NR system to which embodiments of the present invention are applicable.

FIG. 7 is a diagram illustrating a self-contained slot structure based on an NR system to which embodiments of the present invention are applicable.

8 is a diagram illustrating one REG structure based on an NR system to which embodiments of the present invention are applicable.

9 and 10 illustrate exemplary connection schemes of a TXRU and an antenna element.

FIG. 11 is a diagram schematically illustrating a hybrid beamforming structure from a TXRU and a physical antenna perspective according to an embodiment of the present invention.

FIG. 12 is a diagram briefly illustrating a beam sweeping operation for a synchronization signal and system information in a downlink (DL) transmission process according to an embodiment of the present invention.

FIG. 13 is a diagram schematically illustrating an example of a front loaded DMRS of a first DMRS setting type applicable to the present invention.

14 is a view showing a time-domain pattern of the PT-RS applicable to the present invention.

15 illustrates an example of a case where time and / or frequency resources of two PDSCHs applicable to the present invention overlap.

16 is a view showing the operation of the terminal and the base station applicable to the present invention, Figure 17 is a flowchart of the operation of the terminal according to the present invention, Figure 18 is a flowchart of the operation of the base station according to the present invention.

19 is a diagram illustrating a configuration of a terminal and a base station in which the proposed embodiments can be implemented.

20 is a block diagram of a communication device in which proposed embodiments can be implemented.

The following embodiments combine the components and features of the present invention in a predetermined form. Each component or feature may be considered to be optional unless otherwise stated. Each component or feature may be embodied in a form that is not combined with other components or features. In addition, some of the components and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment.

In the description of the drawings, procedures or steps, which may obscure the gist of the present invention, have not been described, and procedures or steps that can be understood by those skilled in the art are not described.

Throughout the specification, when a portion is said to "comprising" (or including) a component, this means that it may further include other components, except to exclude other components unless otherwise stated. do. In addition, the terms "... unit", "... group", "module", etc. described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. It can be implemented as. Also, "a" or "an", "one", "the", and the like shall not be construed herein in the context of describing the present invention (particularly in the context of the following claims). Unless otherwise indicated or clearly contradicted by context, it may be used in the sense including both the singular and the plural.

In the present specification, embodiments of the present invention have been described based on data transmission / reception relations between a base station and a mobile station. Here, the base station is meant as a terminal node of a network that directly communicates with a mobile station. Certain operations described as performed by the base station in this document may be performed by an upper node of the base station in some cases.

That is, various operations performed for communication with a mobile station in a network consisting of a plurality of network nodes including a base station may be performed by the base station or network nodes other than the base station. In this case, the 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), a gNode B (gNB), an advanced base station (ABS), or an access point. Can be.

In addition, in the embodiments of the present invention, a terminal may be a user equipment (UE), a mobile station (MS), a subscriber station (SS), or a mobile subscriber station (MSS). It may be replaced with terms such as a mobile terminal or an advanced mobile station (AMS).

In addition, the transmitting end refers to a fixed and / or mobile node that provides a data service or a voice service, and the receiving end refers to a fixed and / or mobile node that receives a data service or a voice service. Therefore, in uplink, a mobile station may be a transmitting end and a base station may be a receiving end. Similarly, in downlink, a mobile station may be a receiving end and a base station may be a transmitting end.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of wireless access systems IEEE 802.xx system, 3rd Generation Partnership Project (3GPP) system, 3GPP LTE system, 3GPP 5G NR system and 3GPP2 system In particular, embodiments of the present invention may be supported by 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331 documents. That is, obvious steps or portions not described among the embodiments of the present invention may be described with reference to the above documents. In addition, all terms disclosed in the present document can be described by the above standard document.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.

In addition, specific terms used in the embodiments of the present invention are provided to help the understanding of the present invention, and the use of the specific terms may be changed to other forms without departing from the technical spirit of the present invention. .

Hereinafter, a 3GPP NR system will be described as an example of a wireless access system in which embodiments of the present invention can be used.

The following techniques include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and the like. It can be applied to various radio access systems.

In order to clarify the description of the technical features of the present invention, embodiments of the present invention will be described based on the 3GPP NR system. However, the embodiment proposed in the present invention may be equally applied to other wireless systems (eg, 3GPP LTE, IEEE 802.16, IEEE 802.11, etc.).

1. NR 시스템1. NR system

1.1. 물리 채널들 및 일반적인 신호 전송1.1. Physical channels and general signal transmission

In a wireless access system, a terminal receives information from a base station through downlink (DL) and transmits information to the base station through uplink (UL). The information transmitted and received by the base station and the terminal includes general data information and various control information, and various physical channels exist according to the type / use of the information they transmit and receive.

4 is a diagram for explaining physical channels that can be used in embodiments of the present invention and a signal transmission method using the same.

When the power is turned off again or the new terminal enters the cell, the initial cell search operation such as synchronizing with the base station is performed in step S11. To this end, the terminal receives a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the base station, synchronizes with the base station, and obtains information such as a cell ID.

Thereafter, the terminal may receive a physical broadcast channel (PBCH) signal from the base station to obtain broadcast information in a cell.

On the other hand, the terminal may receive a downlink reference signal (DL RS) in the initial cell search step to confirm the downlink channel state.

After completing the initial cell search, the UE receives a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to the physical downlink control channel information in step S12. Specific system information can be obtained.

Subsequently, the terminal may perform a random access procedure such as steps S13 to S16 to complete the access to the base station. To this end, the UE transmits a preamble through a physical random access channel (PRACH) (S13), and a RAR (preamble) for the preamble through a physical downlink control channel and a corresponding physical downlink shared channel. Random Access Response) may be received (S14). The UE transmits a Physical Uplink Shared Channel (PUSCH) using scheduling information in the RAR (S15), and a contention resolution procedure such as receiving a physical downlink control channel signal and a corresponding physical downlink shared channel signal (S16).

After performing the above-described procedure, the UE subsequently receives a physical downlink control channel signal and / or a physical downlink shared channel signal (S17) and a physical uplink shared channel (PUSCH) as a general uplink / downlink signal transmission procedure. A transmission (Uplink Shared Channel) signal and / or a Physical Uplink Control Channel (PUCCH) signal may be transmitted (S18).

The control information transmitted from the terminal to the base station is collectively referred to as uplink control information (UCI). UCI supports Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK (HARQ-ACK / NACK), Scheduling Request (SR), Channel Quality Indication (CQI), Precoding Matrix Indication (PMI), Rank Indication (RI), and Beam Indication (BI). ) Information and the like.

In the NR system, the UCI is generally transmitted periodically through the PUCCH, but may be transmitted through the PUSCH according to an embodiment (eg, when control information and traffic data should be transmitted at the same time). In addition, the UE may transmit UCI aperiodically through the PUSCH by request / instruction of the network.

1.2. 무선 프레임 (Radio Frame) 구조1.2. Radio Frame Structure

Uplink and downlink transmission based on the NR system are based on a frame as shown in FIG. 5. One radio frame has a length of 10 ms and is defined as two 5 ms half-frames (HFs). One half-frame is defined as five 1 ms subframes (SFs). One subframe is divided into one or more slots, and the number of slots in the subframe depends on subcarrier spacing (SCS). Each slot includes 12 or 14 OFDM (A) symbols according to a cyclic prefix (CP). Usually when CP is used, each slot contains 14 symbols. If extended CP is used, each slot includes 12 symbols. Here, the symbol may include an OFDM symbol (or a CP-OFDM symbol) and an SC-FDMA symbol (or a DFT-s-OFDM symbol).

Table 1 shows the number of symbols for each slot according to the SCS, the number of slots for each frame and the number of slots for each subframe when the general CP is used, and Table 2 shows the number of slots for each SCS according to the extended CSP. It indicates the number of symbols, the number of slots per frame, and the number of slots per subframe.

In the table, N ^slot _symb represents the number of symbols in a slot, N ^{frame, μ} _slot represents the number of _slots in a frame ^, and N ^{subframe, μ} _slot represents the number of slots in a ^subframe .

In the NR system to which the present invention is applicable, OFDM (A) numerology (eg, SCS, CP length, etc.) may be set differently between a plurality of cells merged into one UE. Accordingly, the (absolute time) section of a time resource (eg, SF, slot, or TTI) (commonly referred to as a time unit (TU) for convenience) composed of the same number of symbols may be set differently between merged cells.

One slot includes a plurality of symbols in the time domain. For example, one slot includes seven symbols in the case of a normal CP, but one slot includes six symbols in the case of an extended CP.

A carrier includes a plurality of subcarriers in the frequency domain. Resource block (RB) is defined as a plurality of consecutive subcarriers (eg, 12) in the frequency domain.

A bandwidth part (BWP) is defined as a plurality of consecutive (P) RBs in the frequency domain and may correspond to one numerology (eg, SCS, CP length, etc.).

The carrier may include up to N (eg 5) BWPs. Data communication is performed through an activated BWP, and only one BWP may be activated by one UE. Each element in the resource grid is referred to as a resource element (RE), one complex symbol may be mapped.

In FIG. 7, a hatched area (eg, symbol index = 0) represents a downlink control area, and a black area (eg, symbol index = 13) represents an uplink control area. The other region (eg, symbol index = 1 to 12) may be used for downlink data transmission or may be used for uplink data transmission.

According to this structure, the base station and the UE may sequentially perform DL transmission and UL transmission in one slot, and may transmit and receive DL data and transmit and receive UL ACK / NACK for the DL data in the one slot. As a result, this structure reduces the time taken to retransmit data in the event of a data transmission error, thereby minimizing the delay of the final data transfer.

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

In the above detailed description, the case in which the independent slot structure includes both the DL control region and the UL control region has been described. However, the control regions may be selectively included in the independent slot structure. In other words, the independent slot structure according to the present invention may include not only the case of including both the DL control region and the UL control region as shown in FIG. 7 but also the case of including only the DL control region or the UL control region.

In addition, the order of the regions constituting one slot may vary according to embodiments. For example, one slot may be configured in the order of a DL control area / DL data area / UL control area / UL data area, or may be configured in the order of a UL control area / UL data area / DL control area / DL data area.

The PDCCH may be transmitted in the DL control region, and the PDSCH may be transmitted in the DL data region. PUCCH may be transmitted in the UL control region, and PUSCH may be transmitted in the UL data region.

Downlink Control Information (DCI), for example, DL data scheduling information, UL data scheduling information, and the like may be transmitted in the PDCCH. In PUCCH, uplink control information (UCI), for example, positive acknowledgment / negative acknowledgment (ACK / NACK) information, channel state information (CSI) information, and scheduling request (SR) for DL data may be transmitted.

The PDSCH carries downlink data (eg, DL-shared channel transport block, DL-SCH TB), and modulation methods such as Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64 QAM, and 256 QAM are used. Apply. A codeword is generated by encoding the TB. The PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and modulation symbols generated from each codeword are mapped to one or more layers. Each layer is mapped to a resource together with a DMRS (Demodulation Reference Signal) to generate an OFDM symbol signal, and is transmitted through a corresponding antenna port.

The PDCCH carries downlink control information (DCI) and a QPSK modulation method is applied. One PDCCH is composed of 1, 2, 4, 8, 16 CCEs (Control Channel Elements) according to an aggregation level (AL). One CCE consists of six Resource Element Groups (REGs). One REG is defined by one OFDM symbol and one (P) RB.

In FIG. 8, D represents a resource element (RE) to which DCI is mapped, and R represents an RE to which DMRS is mapped. DMRS is mapped to the 1st, 5th, 9th RE in the frequency domain direction in one symbol.

The PDCCH is transmitted through a control resource set (CORESET). CORESET is defined as a REG set with a given pneumonology (eg SCS, CP length, etc.). A plurality of CORESET for one terminal may be overlapped in the time / frequency domain. CORESET may be set through system information (eg, MIB) or UE-specific higher layer (eg, Radio Resource Control, RRC, layer) signaling. In detail, the number of RBs and the number of symbols (up to three) constituting the CORESET may be set by higher layer signaling.

PUSCH carries uplink data (eg, UL-shared channel transport block, UL-SCH TB) and / or uplink control information (UCI), and uses a Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) waveform. Or based on a Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) waveform. When the PUSCH is transmitted based on the DFT-s-OFDM waveform, the terminal transmits the PUSCH by applying transform precoding. For example, when transform precoding is not possible (eg, transform precoding is disabled), the UE transmits a PUSCH based on a CP-OFDM waveform, and when conversion precoding is possible (eg, transform precoding is enabled), the UE is CP-OFDM. PUSCH may be transmitted based on the waveform or the DFT-s-OFDM waveform. PUSCH transmissions are dynamically scheduled by UL grants in DCI or semi-static based on higher layer (eg RRC) signaling (and / or Layer 1 (L1) signaling (eg PDCCH)). Can be scheduled (configured grant). PUSCH transmission may be performed based on codebook or non-codebook.

The PUCCH carries uplink control information, HARQ-ACK and / or scheduling request (SR), and is divided into Short PUCCH and Long PUCCH according to the PUCCH transmission length. Table 3 illustrates the PUCCH formats.

PUCCH format 0 carries a maximum of 2 bits of UCI, and is mapped and transmitted based on a sequence. Specifically, the terminal transmits one sequence of the plurality of sequences through the PUCCH of PUCCH format 0 to transmit a specific UCI to the base station. The UE transmits the PUCCH having PUCCH format 0 in the PUCCH resource for the SR configuration only when transmitting the positive SR.

PUCCH format 1 carries a UCI of up to two bits in size, and modulation symbols are spread by an orthogonal cover code (OCC) (set differently depending on whether frequency hopping) in the time domain. The DMRS is transmitted in a symbol in which a modulation symbol is not transmitted (that is, transmitted by time division multiplexing (TDM)).

PUCCH format 2 carries a UCI having a bit size larger than 2 bits, and modulation symbols are transmitted by DMRS and Frequency Division Multiplexing (FDM). The DM-RS is located at symbol indexes # 1, # 4, # 7 and # 10 in a given resource block with a density of 1/3. PN (Pseudo Noise) sequence is used for the DM_RS sequence. Frequency hopping may be activated for two symbol PUCCH format 2.

PUCCH format 3 is not UE multiplexed in the same physical resource blocks and carries a UCI of a bit size larger than 2 bits. In other words, the PUCCH resource of PUCCH format 3 does not include an orthogonal cover code. The modulation symbol is transmitted after being time division multiplexed (DMD) with DMRS.

PUCCH format 4 supports multiplexing up to 4 terminals in the same physical resource block, and carries UCI of a bit size larger than 2 bits. In other words, the PUCCH resource in PUCCH format 3 includes an orthogonal cover code. The modulation symbol is transmitted after being time division multiplexed (DMD) with DMRS.

1.3. 아날로그 빔포밍 (Analog beamforming)1.3. Analog beamforming

In millimeter wave (mmW), the short wavelength allows the installation of multiple 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 installed in a 2-dimension array at 0.5 lambda intervals on a 5 * 5 cm panel. Accordingly, in millimeter wave (mmW), a plurality of antenna elements may be used to increase beamforming (BF) gain to increase coverage or to increase throughput.

In this case, each antenna element may include a TXRU (Transceiver Unit) to enable transmission power and phase adjustment for each antenna element. Through this, each antenna element may perform independent beamforming for each frequency resource.

However, in order to install TXRU in all 100 antenna elements, there is a problem in terms of cost effectiveness. Therefore, a method of mapping a plurality of antenna elements to one TXRU and adjusting the direction of the 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 made in the entire band.

As a solution to this problem, a hybrid BF having a number of B TXRUs smaller than Q antenna elements may be considered as an intermediate form between digital beamforming and analog beamforming. In this case, although there are differences depending on the connection scheme of the B TXRU and the Q antenna elements, the direction of the beam that can be transmitted simultaneously may be limited to B or less.

9 and 10 illustrate exemplary connection schemes of a TXRU and an antenna element. Here, the TXRU virtualization model represents the relationship between the output signal of the TXRU and the output signal of the antenna element.

FIG. 9 is a diagram illustrating how a TXRU is connected to a sub-array. In the case of FIG. 9, the antenna element is connected to only one TXRU.

10 shows how TXRU is connected to all antenna elements. In the case of FIG. 10, the antenna element is connected to all TXRUs. At this time, the antenna element requires a separate adder as shown in FIG. 10 to be connected to all TXRUs.

9 and 10, W denotes a phase vector multiplied by an analog phase shifter. That is, W is the main parameter that determines the direction of analog beamforming. Here, the mapping between the CSI-RS antenna port and the TXRUs may be 1: 1 or 1: 1-to-many.

According to the configuration of FIG. 9, although focusing of beamforming is difficult, there is an advantage that the entire antenna configuration can be configured at a low cost.

According to the configuration of FIG. 10, there is an advantage in that focusing of beamforming is easy. However, since the TXRU is connected to all antenna elements, the overall 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 may be applied. In this case, analog beamforming (or RF (Radio Frequency) beamforming) refers to an operation of performing precoding (or combining) in the RF stage. In the hybrid beamforming, the baseband stage and the RF stage respectively perform precoding (or combining). This reduces the number of RF chains and the number of digital-to-analog (D / A) (or analog-to-digital) converters while providing near-digital beamforming performance.

For convenience of description, the hybrid beamforming structure may be represented by N transceiver units (TXRUs) and M physical antennas. In this case, the digital beamforming for the L data layers to be transmitted by the transmitter may be represented by an N * L (N by L) matrix. Thereafter, the converted N digital signals are converted into analog signals through TXRU, and analog beamforming is applied to the converted signals represented by an M * N (M by N) matrix.

FIG. 11 is a diagram schematically illustrating a hybrid beamforming structure from a TXRU and a physical antenna perspective according to an embodiment of the present invention. In this case, in FIG. 11, the number of digital beams is L and the number of analog beams is N.

In addition, in the NR system to which the present invention is applicable, the base station is designed to change the analog beamforming in units of symbols to consider a method for supporting more efficient beamforming for a terminal located in a specific region. Furthermore, when defining specific N TXRU and M RF antennas as one antenna panel as shown in FIG. 11, in the NR system according to the present invention, a plurality of antenna panels to which hybrid beamforming independent of each other are applicable may be defined. It is also considered to adopt.

As described above, when the base station uses a plurality of analog beams, the analog beams advantageous for signal reception may be different for each terminal. Accordingly, in the NR system to which the present invention is applicable, the base station transmits a signal (at least a synchronization signal, system information, paging, etc.) by applying a different analog beam for each symbol within a specific subframe (SF) or slot. Beam sweeping operation that allows the UE to have a reception opportunity is being considered.

In FIG. 12, a physical resource (or physical channel) through which system information of an NR system to which the present invention is applicable is transmitted in a broadcasting manner is referred to as a physical broadcast channel (xPBCH). In this case, analog beams belonging to different antenna panels in one symbol may be transmitted simultaneously.

In addition, as shown in FIG. 12, in the NR system to which the present invention is applicable, as a configuration for measuring channels for analog beams, a reference signal transmitted by applying a single analog beam (corresponding to a specific antenna panel) is transmitted. A beam reference signal (Beam RS, BRS), which is RS, may be introduced. The BRS may be defined for a plurality of antenna ports, and each antenna port of the BRS may correspond to a single analog beam. At this time, unlike the BRS, the synchronization signal or the xPBCH may be transmitted by applying all the analog beams in the analog beam group so that any terminal can receive well.

1.4. DMRS (Demodulation Reference Signal)1.4. DMRS (Demodulation Reference Signal)

In the NR system to which the present invention is applicable, the DMRS may be transmitted and received in a first load structure. Alternatively, an additional DMRS (Additional DMRS) other than the first DMRS may be additionally transmitted and received.

Front loaded DMRS can support fast decoding. The first OFDM symbol carrying the front loaded DMRS may be determined as a third (eg l = 2) or a fourth OFDM symbol (eg l = 3). The first FODM symbol location may be indicated by a physical broadcast channel (PBCH).

The number of OFDM symbols occupied by the front loaded DMRS may be indicated by a combination of downlink control information (DCI) and radio resource control (RRC) signaling.

Additional DMRS may be set for a high speed terminal. Additional DMRS may be located in the middle / last symbol (s) in the slot. When one Front loaded DMRS symbol is set, Additional DMRS may be allocated to 0 to 3 OFDM symbols. When two front loaded DMRS symbols are set, additional DMRS may be allocated to 0 to 2 OFDM symbols.

Front loaded DMRS is composed of two types, and one of the two types may be indicated through higher layer signaling (eg, RRC signaling).

In the present invention, two DMRS configuration types may be applied. The DMRS configuration type substantially configured for the UE among the two DMRS configuration types may be indicated by higher layer signaling (eg, RRC).

In the case of the first DMRS configuration type (DMRS configuration type 1), it may be classified as follows according to the number of OFDM symbols to which the front loaded DMRS is allocated.

Number of OFDM symbols to which the first DMRS configuration type (DMRS configuration type 1) and the front loaded DMRS are allocated = 1

Up to four ports (eg, P0 to P3) can be multiplexed based on the length-2 F-CDM (Frequency-Code Division Multiplexing) and FDM (Frequency Division Multiplexing) methods. RS density may be set to 6 RE per port in RB (Resource Block).

Number of OFDM symbols to which the first DMRS configuration type 1 and the front loaded DMRS are allocated = 2

Up to eight ports (eg, P0 to P7) can be multiplexed based on length-2 F-CDM, length-2 time-code division multiplexing (T-CDM), and FDM methods. Here, when the existence of the PT-RS is set by higher layer signaling, the T-CDM may be fixed to [1 1]. RS density can be set to 12 REs per port in the RB.

In the case of the second DMRS configuration type (DMRS configuration type 2), it may be classified as follows according to the number of OFDM symbols to which the front loaded DMRS is allocated.

The number of OFDM symbols to which the second DMRS configuration type (DMRS configuration type 2) and the front loaded DMRS are allocated = 1

Up to six ports (eg, P0 through P5) can be multiplexed based on the length-2 F-CDM and FDM methods. RS density may be set to 4 RE per port in RB (Resource Block).

The number of OFDM symbols to which the second DMRS configuration type (DMRS configuration type 2) and the front loaded DMRS are allocated = 2

Up to twelve ports (eg P0-P11) can be multiplexed based on the length-2 F-CDM, length-2 T-CDM and FDM methods. Here, when the existence of the PT-RS is set by higher layer signaling, the T-CDM may be fixed to [1 1]. RS density may be set to 8 REs per port in the RB.

More specifically, FIG. 13 (a) shows a structure in which a DMRS is loaded on one symbol first, and FIG. 13 (b) shows a structure in which the DMRS is loaded on two symbols first. DMRS with two symbols).

In Fig. 13, Δ means a DMRS offset value on the frequency axis. In this case, DMRS ports having the same Δ may be code division multiplexing in frequency domain (CDM-F) or code division multiplexing in time domain (CDM-T) in the frequency domain. . In addition, DMRS ports having different Δ may be CDM-F.

According to the invention, CDM-F is obtained according to the

And CDM-T can be applied based on the

Can be applied on the basis of In this case, k 'and l' are parameter values that determine the subcarrier index to which the corresponding DMRS is mapped, and may have a value of 0 or 1. The DMRS corresponding to each DMRS port may be divided into CDM groups as shown in the following table according to the DMRS configuration type.

Table 4 below shows parameters for a first DMRS configuration type for PDSCH, and Table 5 shows parameters for a second DMRS configuration type for PDSCH.

The terminal may acquire DMRS port configuration information set by the base station through the DCI. For example, the DMRS configuration type (eg, first DMRS configuration type (dmrs-Type = 1), the second DMRS configuration type (dmrs-Type = 2)) configured for the UE, the maximum number of OFDM symbols for the DL front loaded DMRS ( For example, based on maxLength = 1 or maxLength = 2), the UE may obtain DMRS port configuration information through an antenna ports field of DCI format 1_1. More specifically, Table 6 shows DMRS port configuration information according to the value of the antenna port field when (dmrs-Type = 1 and maxLength = 1) is set for the terminal, and Table 7 shows (dmrs-Type = 1 and maxLength for the terminal). = 2) is set, this indicates DMRS port configuration information according to the value of the antenna port field. Table 8 shows DMRS port configuration information according to the value of the antenna port field when (dmrs-Type = 2 and maxLength = 1) is set for the UE. Table 9 shows (dmrs-Type = 2 and maxLength = 2) for the UE. When set, this indicates DMRS port configuration information according to the value of the antenna port field.

In this case, the terminal may perform DMRS reception according to the condition as follows.

In DMRS setup type 1,

One codeword is scheduled for the terminal and indicates one of {2, 9, 10, 11, 30} as an index value related to antenna port mapping (for example, the index value of Table 6 or Table 7). To be assigned a DCI,

When two codewords are scheduled to the terminal,

The terminal may receive DMRS under the assumption that all remaining orthogonal antenna ports are not associated with PDSCH transmission to other terminals.

In DMRS setup type 2,

One codeword is scheduled for the terminal, and the terminal is assigned a DCI indicating one of {2, 10, 23} as an index value related to antenna port mapping (for example, an index value of Table 8 or Table 9). Or

When two codewords are scheduled to the terminal,

1.5. PT-RS (Phase Tracking Reference Signal)1.5. PT-RS (Phase Tracking Reference Signal)

Phase noise related to the present invention will be described. Jitter occurring on the time axis appears as phase noise on the frequency axis. This phase noise randomly changes the phase of the received signal on the time axis as in the following equation.

In Equation 1,

The parameters represent the phase rotation values due to the received signal, time axis signal, frequency axis signal and phase noise, respectively. When the received signal in Equation 1 undergoes a Discrete Fourier Transform (DFT) process, Equation 2 below is derived.

In Equation 2,

The parameters represent Common Phase Error (CPE) and Inter Cell Interference (ICI), respectively. In this case, as the correlation between phase noises increases, the CPE of Equation 2 has a larger value. The CPE is a type of carrier frequency offset (CFO) in a WLAN system, but from the viewpoint of the terminal, the CPE and the CFO can be similarly interpreted.

The UE removes the CPE / CFO, which is the phase noise on the frequency axis by estimating the CPE / CFO, and the process of estimating the CPE / CFO for the received signal is a process that must be preceded for accurate decoding of the received signal. Accordingly, the base station may transmit a predetermined signal to the terminal so that the terminal can accurately estimate the CPE / CFO, the signal may be a pilot signal shared in advance between the terminal and the base station as a signal for estimating the phase noise. And the data signal may be a changed or duplicated signal. Hereinafter, a series of signals for estimating phase noise will be called PT-RS (Phase Tracking Reference Signal).

Basically, when the upper layer parameter DMRS-DownlinkConfig (or higher layer parameters DMRS-UplinkConfig) within the upper layer parameter phaseTrackingRS set, the UE can receive the PT-RS assuming that PT-RS are present. However, (i) if the layer parameter phaseTrackingRS is not set, or (ii) if a higher layer parameter phaseTrackingRS is set but satisfies a predetermined condition (eg, i) a scheduled MCS (Modulation and Coding Scheme) is less than a certain value, or ii The number of scheduled RBs is less than a certain number, or iii) the associated Random Network Temporary Identifier (RNTI) is a Random Access RNTI (RA-RNTI), a System Information RNTI (SI-RNTI), a Paging RNTI (P-RNTI), etc. ), The terminal may assume that there is no PT-RS.

In the UL PT-RS, a specific method of transmitting a UL PT-RS of a UE may be different according to whether to enable / disable transform precoding. However, in common, the UL PT-RS may be transmitted only within a resource block for PUSCH. Characteristically, when transform precoding is disabled, the UL PT-RS may be mapped to subcarriers for the DMRS port associated with that PT-RS port, and resources allocated for PUSCH transmission based on the frequency density described below. Some of the blocks may be mapped to resource blocks.

For the DL PT-RS, the DL PT-RS can be transmitted only within a resource block for the PDSCH, can be mapped to subcarriers for the DMRS port associated with that PT-RS port, and based on the frequency density described below It may be mapped to some resource blocks of the resource blocks allocated for PDSCH transmission.

1.5.1. Time domain pattern (or time density)

As shown in FIG. 14, the PT-RS may have a different (time) pattern according to the Modulation and Coding Scheme (MCS) level applied.

In this case, the time density 1 may correspond to Pattern # 1 of FIG. 14, the time density 2 may correspond to Pattern # 2 of FIG. 14, and the time density 4 may correspond to Pattern # 3 of FIG. 14.

Parameters ptrs-MCS1, ptrs-MCS2, ptrs-MCS3, and ptrs-MCS4 constituting Table 10 may be defined by higher layer signaling.

1.5.2. Frequency Domain Pattern (or Frequency Density)

The PT-RS according to the present invention may be transmitted by being mapped to one subcarrier for each RB (Resource Block), one subcarrier for every two RBs, or one subcarrier for every four RBs. In this case, the frequency domain pattern (or frequency density) of the PT-RS may be set according to the size of the scheduled bandwidth.

In this case, frequency density 2 corresponds to a frequency domain pattern in which PT-RSs are mapped to one subcarrier every two RBs, and frequency density 4 corresponds to frequency in which PT-RSs are mapped to one subcarrier every four RBs. It may correspond to an area pattern.

In the above configuration, N _RB0 and N _{RB1, which} are reference values of the scheduled bandwidth for determining the frequency density, may be defined by higher layer signaling.

1.6. DCI 포맷1.6. DCI format

In the NR system to which the present invention is applicable, the following DCI formats can be supported. First, the NR system may support DCI format 0_0 and DCI format 0_1 as a DCI format for PUSCH scheduling, and support DCI format 1_0 and DCI format 1_1 as a DCI format for PDSCH scheduling. In addition, as a DCI format usable for other purposes, the NR system may additionally support DCI format 2_0, DCI format 2_1, DCI format 2_2, and DCI format 2_3.

Here, DCI format 0_0 is used for scheduling TB (Transmission Block) based (or TB-level) PUSCH, and DCI format 0_1 is used for TB (Transmission Block) based (or TB-level) PUSCH or (CBG (Code Block Group) Base signal transmission / reception may be used to schedule a CBG-based (or CBG-level) PUSCH.

In addition, DCI format 1_0 is used for scheduling TB-based (or TB-level) PDSCH, DCI format 1_1 is used for TB-based (or TB-level) PDSCH or CBG-based (or CBG-based signal transmission and reception). level) may be used to schedule the PDSCH.

In addition, DCI format 2_0 is used for notifying the slot format (used for notifying the slot format), and DCI format 2_1 is used for notifying PRB and OFDM symbols assuming that a specific UE has no intended signal transmission ( used for notifying the PRB (s) and OFDM symbol (s) where UE may assume no transmission is intended for the UE), DCI format 2_2 is used for the transmission of Transmission Power Control (TPC) commands of PUCCH and PUSCH. The DCI format 2_3 may be used for transmission of a TPC command group for SRS transmission by one or more UEs (used for the transmission of a group of TPC commands for SRS transmissions by one or more UEs).

More specifically, DCI format 1_1 includes an MCS / NDI (New Data Indicator) / RV (Redundancy Version) field for transport block (TB) 1, and the upper layer parameter maxNrofCodeWordsScheduledByDCI in the upper layer parameter PDSCH-Config is n2 (that is, 2), may further include an MCS / NDI / RV field for transport block 2.

In particular, when the upper layer parameter maxNrofCodeWordsScheduledByDCI is set to n2 (that is, 2), substantially whether the transport block is enabled (disable / disable) may be determined by a combination of the MCS field and the RV field. More specifically, when the MCS field for a specific transport block has a value of 26 and the RV field has a value of 1, the specific transport block may be disabled.

Specific features for the DCI format may be supported by the 3GPP TS 38.212 document. That is, obvious steps or parts which are not described among DCI format-related features may be described with reference to the above document. In addition, all terms disclosed in the present document can be described by the above standard document.

1.7. CORESET (Control resource set)1.7. CORESET (Control resource set)

One CORESET includes N ^CORESET _RB RBs in the frequency domain, and includes N ^CORESET _symb symbols (

times

1, 2, and 3 values) in the time domain.

One control channel element (CCE) includes 6 resource element groups (REGs), and one REG is equal to one RB on one OFDM symbol. REGs in CORESET are numbered in order according to a time-first manner. Specifically, the numbering starts from '0' for the first OFDM symbol and the lowest-numbered RB in CORESET.

A plurality of CORESETs may be set for one terminal. Each CORESET is related to only one CCE-to-REG mapping.

CCE-to-REG mapping for one CORESET may be interleaved or non-interleaved.

Configuration information for the CORESET may be set by the upper layer parameter ControlResourceSet IE.

In addition, the configuration information for CORESET 0 (eg common CORESET) may be set by the upper layer parameter ControlResourceSetZero IE.

1.8. 안테나 포트 의사 코-로케이션 (antenna ports quasi co-location)1.8. Antenna ports quasi co-location

A list of the maximum M Transmission Configuration Indicator (M TCI) state configuration may be configured for one UE. The maximum M TCI state setting may be set by a higher layer parameter PDSCH-Config so that (the UE) can decode PDSCH upon detection of a PDCCH including an (intended) DCI intended for the UE and a given serving cell. have. Here, the M value may be determined depending on the capability of the terminal.

Each TCI-state includes a parameter for configuring a quasi co-location (QCL) relationship between one or two downlink reference signals and DMRS ports of the PDSCH. The QCL relationship is established based on the upper layer parameter qcl-Type1 for the first downlink reference signal (DL RS) and the upper layer parameter qcl-Type2 (if set) for the second DL RS. For the case of two DL RSs, the QCL types should not be the same regardless of whether the reference signals are the same DL RS or different DL RS. The QCL types correspond to each DL RS given by the higher layer parameter qcl-Type in the higher layer parameter QCL-Info , and the QCL types may have one of the following values.

'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

-'QCL-TypeB': {Doppler shift, Doppler spread}

-'QCL-TypeC': {Doppler shift, average delay}

'QCL-TypeD': {Spatial Rx parameter}

The terminal receives an activation command used to map the maximum 8 TCI states with a codepoint of a Transmission Configuration Indication (TCI) field in DCI. When the HARQ-ACK signal corresponding to the PDSCH including the activation command is transmitted in slot #n, the mapping between the code points of the TCI states and the TCI field in the DCI is slot # (n + 3 * N ^{subframe, μ} _slot + Applicable from 1). Here, N ^{subframe, μ} _slot is determined based on Table 1 or Table 2 described above. After the UE receives an initial higher layer configuration of TCI states and before the UE receives an activation command, the UE determines that the DMRS port (s) of the PDSCH of the serving cell is 'QCL-TypeA'. From the point of view, it is assumed that the SS / PBCH block and the QCL determined in the initial access procedure. In addition, at this time, the UE may assume that the DMRS port (s) of the PDSCH of the serving cell are QCLed with the SS / PBCH block determined in the initial access procedure in terms of 'QCL-TypeD'.

When the upper layer parameter tci-PresentInDCI is set to 'enabled' for CORESET scheduling PDSCH, the UE assumes that the TCI field exists in the PDCCH of DCI format 1_1 transmitted on the CORESET. The upper layer parameter tci-PresentInDCI is not set for CORESET scheduling the PDSCH or the PDSCH is scheduled by DCI format 1_0, and the time offset between the reception time of the DL DCI and the reception time of the PDSCH corresponding to the threshold Threshold-Sched If greater than or equal to -Offset (the threshold value is determined based on the reported UE capability ), to determine the PDSCH antenna port QCL, the UE determines that the TCI state or QCL assumption for the PDSCH is used for PDCCH transmission. It is assumed to be the same as the TCI state or QCL assumption applied to.

If the upper layer parameter tci-PresentInDCI is set to 'enabled' and the TCI field in DCI scheduling a CC (component carrier) indicates an activated TCI states in the scheduled CC or DL BW (point to), the PDSCH Is scheduled by DCI format 1_1, the UE uses the TCI-State based on the TCI field included in the DCI in the detected PDCCH to determine the PDSCH antenna port QCL. If the time offset between the reception time of the DL DCI and the reception time of the corresponding PDSCH is greater than or equal to a threshold Threshold-Sched-Offset (the threshold value is determined based on the reported UE capability), the UE may determine the PDSCH of the serving cell. Assume that the DMRS port (s) are QCLed with RS (s) in the TCI state for the QCL type parameter (s) given by the indicated TCI stated. When a single slot PDSCH is configured for the terminal, the indicated TCI state should be based on activated TCI states in a slot of the scheduled PDSCH. When a CORESET associated with a search space set for cross-carrier scheduling is configured for the terminal, the terminal assumes that a higher layer parameter tci-PresentInDC I is set to 'enabled' for the CORESET. When one or more TCI states configured for the serving cell scheduled by the search region set include 'QCL-TypeD', the UE may determine the time between the reception time of the detected PDCCH in the search region set and the reception time of the corresponding PDSCH. The offset is expected to be greater than or equal to the threshold Threshold-Sched-Offset .

If both the upper layer parameter tci-PresentInDC I is set to 'enabled' or the upper layer parameter tci-PresentInDC I is not set in RRC connected mode, offset between the reception time of the DL DCI and the reception time of the corresponding PDSCH. If the threshold is smaller than Threshold-Sched-Offset , the terminal assumes the following. (i) The DMRS port (s) of the PDSCH of the serving cell have a QCL relationship with respect to the QCL parameter (s) and RS (s) of the TCI state. (ii) In this case, the QCL parameter (s) is for the PDCCH QCL indication of the CORESET associated with the search area monitored to the lowest CORESET-ID in the last slot in one or more CORESET in the active BWP of the serving cell monitored by the terminal. (For both the cases when higher layer parameter tci-PresentInDCI is set to 'enabled' and the higher layer parameter tci-PresentInDCI is not configured in RRC connected mode, if the offset between the reception of the DL DCI and the corresponding PDSCH is less than the threshold Threshold-Sched-Offset, the UE may assume that the DM-RS ports of PDSCH of a serving cell are quasi co-located with the RS (s) in the TCI state with respect to the QCL parameter (s) used for PDCCH quasi co-location indication of the CORESET associated with a monitored search space with the lowest CORESET-ID in the latest slot in which one or more CORESETs within the active BWP of the serving cell are monitored by the UE.)

In this case, when the 'QCL-TypeD' of the PDSCH DMRS is different from the 'QCL-TypeD' of the PDCCH DMRS overlapping on at least one symbol, the UE expects to prioritize the reception of the PDCCH associated with the corresponding CORESET. The operation may also apply equally to intra band CA cases (when PDSCH and CORESET are on different CCs). If there is no TCI state including 'QCL-TypeD' among the configured TCI states, the UE indicates a TCI indicated for the scheduled PDSCH regardless of a time offset between a reception time of a DL DCI and a reception time of a corresponding PDSCH. Get different QCL assumptions from state.

For the periodic CSI-RS resource in the higher layer parameter NZP-CSI-RS-ResourceSet with the higher layer parameter trs-Info set, the terminal should assume that the TCI state indicates one of the following QCL type (s):

'QCL-TypeC' for an SS / PBCH block, 'QCL-TypeD' for the same SS / PBCH block (when applicable), or

'QCL-TypeC' for the SS / PBCH block and, if applicable (QCL-TypeD), 'QCL for periodic CSI-RS resources in the upper layer parameter NZP-CSI-RS-ResourceSet with higher layer parameter repetition set -TypeD '

For the CSI-RS resource in the higher layer parameter NZP-CSI-RS-ResourceSet configured without the higher layer parameter trs-Info and the higher layer parameter repetition , the terminal should assume that the TCI state indicates one of the following QCL type (s). :

'QCL-TypeA' for the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet in which the upper layer parameter trs-Info is set, and (QCL-TypeD), if applicable, for the same CSI-RS resource. 'QCL-TypeD', or

'QCL-TypeA' for the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet in which the upper layer parameter trs-Info is set, and 'QCL-TypeD' for the SS / PBCH block, if applicable. QCL-TypeD ', or

-'QCL-TypeA' for the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet in which the upper layer parameter trs-Info is set, and the upper layer parameter repetition is set if (QCL-TypeD) is applicable. 'QCL-TypeD' for periodic CSI-RS resources in layer parameter NZP-CSI-RS-ResourceSet , or

-'QCL-TypeB', 'QCL-TypeD' for CSI-RS resource in upper layer parameter NZP-CSI-RS-ResourceSet where upper layer parameter trs-Info is set is not applicable

For the CSI-RS resource in the higher layer parameter NZP-CSI-RS-ResourceSet in which the higher layer parameter repetition is configured, the terminal should assume that the TCI state indicates one of the following QCL type (s):

-'QCL-TypeA' for the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet in which the upper layer parameter trs-Info is set, and the upper layer parameter repetition is set if (QCL-TypeD) is applicable. 'QCL-TypeD' for CSI-RS resource in layer parameter NZP-CSI-RS-ResourceSet , or

'QCL-TypeC' for the SS / PBCH block and 'QCL-TypeD' for the same SS / PBCH block, if applicable (QCL-TypeD)

For DMRS of PDCCH, the UE should assume that the TCI status indicates one of the following QCL type (s):

'QCL-TypeA' for the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet set without the upper layer parameter trs-Info and the upper layer parameter repetition and, if applicable (QCL-TypeD), the same CSI 'QCL-TypeD' for -RS resource

For DMRS of PDSCH, the UE should assume that the TCI status indicates one of the following QCL type (s):

2. 제안하는 실시예2. Proposed Example

Hereinafter, the configuration proposed by the present invention will be described in more detail based on the technical spirit as described above.

In the following description, the T / F resource may refer to a time and / or frequency resource.

In the following description, assume a case where the T / F resources of each PDSCH (eg, PDSCH # 0 and PDSCH # 1) that are transmitted in different transmission and reception points (TRPs) (or beams or panels) overlap. In this case, the case where the T / F resources overlap may include all five cases shown in FIG. 15. In addition, according to an embodiment in the following description, “TRP” may be extended to “beam” or “signal (spatial) resources”.

As shown in FIG. 15, two PDSCHs may partially overlap (eg, case # 1 through # 3) or may overlap on one of the time domain or frequency domain of the two PDSCHs (eg case # 4). , # 5). In Case # 1 / # 2 / # 3 of FIG. 15, two PDSCHs overlap (partially) in both time and frequency. In Case # 4 of FIG. 15, two PDSCHs do not overlap only on a time axis. In Case # 5 of FIG. 15, two PDSCHs overlap in the time axis but do not overlap in the frequency axis.

In the following description, time axis resources of PDSCHs transmitting on different TRPs (or beams) respectively overlap (partially) or overlap (partially) in the time and frequency axis (e.g. case # 5). In case # 1, # 2, # 3, the transmission of the two PDSCHs is referred to as non-coherent joint transmission (NC-JT).

In the following description, a single DCI based NC-JT (hereinafter referred to as Single DCI based NC-JT for convenience of description) means that PDSCHs transmitted in the different TRPs (or beams) are scheduled by one DCI, respectively. do. For example, Single DCI based NC-JT may include a configuration in which DCI # 1 simultaneously schedules PDSCH # 1 / # 2 for different TRPs.

In the following description, a multi-DCI based NC-JT (hereinafter referred to as Multi DCI based NC-JT for convenience of description) means that PDSCHs transmitted in the different TRPs (or beams) in each DCI are scheduled. . For example, the Multi DCI based NC-JT may include a configuration in which DCI # 1 / # 2 simultaneously schedules PDSCH # 1 / # 2.

In the present invention, NC-JT can be classified into two types depending on whether the layers transmitted by different TRPs are independent or common.

For example, if the layers are independent, the UE may expect a total of seven layers if TRP # A transmits three layers and TRP # B transmits four layers. On the other hand, if the layers are common, if TRP # A transmits three layers and TRP # B transmits three layers, the UE can expect a total of three layers.

In order to distinguish the two, the preceding NC-JT may be named NC-JT with IL (Independent Layer), and the subsequent NC-JT may be named NC-JT with CL (Common Layer).

The technical configurations proposed in the present invention are basically based on NC-JT with IL, but the configuration of the present invention is not limited thereto and may be extended to NC-JT with CL.

Hereinafter, a signaling method applicable to a case where an NC-JT situation is configured for a specific terminal will be described in detail.

The base station may use two DCIs to schedule different PDSCHs (partially or wholly) overlaid on a specific UE to T / F resources that overlap each other. This may be similar to multiplexing the specific UE with other UEs. This is because a PDSCH scheduled by one DCI acts as an interference to a PDSCH scheduled by another DCI. (Weight lifting)

Therefore, in this case, the UE can design a reception filter or define a reception beam differently so as to minimize interference between different PDSCHs (for example, two PDSCHs are received through different reception beams).

However, in some cases, the UE may miss one of the two DCIs. In this case, the missing of the signal may mean that the signal itself is not transmitted or that the signal is transmitted, but the signal is not normally detected / decoded. Accordingly, the UE may not know (ie, may not recognize) the transmission of the PDSCH itself scheduled by the missed DCI. Accordingly, the UE must recognize the presence of the PDSCH scheduled by the missed DCI through blind detection. That is, this may increase the complexity of the terminal.

Looking at the configuration from the receiver implementation point of view of the terminal, the terminal may use an IRC (Interference Rejection Combining) filter to remove the interference between PDSCH. To this end, the terminal may recognize the DMRS port (s) corresponding to each of the PDSCH based on the received DCI, and then calculate the IRC receiver filter through channel estimation.

However, when the terminal misses one of the DCIs, the terminal may not recognize the DMRS port (s) of the PDSCH scheduled by the missed DCI. Accordingly, the terminal should perform blind detection to detect the DMRS port (s). In other words, this increases the complexity of the terminal. In addition, when the terminal detects a wrong DMRS port (s) (that is, when the base station does not detect the intended DMRS port (s)), rather, the performance is reduced.

Therefore, in order to prevent the complexity reduction due to the blind detection of the terminal and the performance decrease due to the false detection, the base station may not only perform other than the DMRS port (s) of the PDSCH scheduled by the DCIs through DCIs used for NC-JT mode / transmission. DCIs need to inform the DMRS port (s) of the PDSCH scheduling.

As described above, Table 7 shows various DMRS port combinations that can be allocated to the terminal when the first DMRS configuration type is set in the terminal (ie, when the upper layer parameter DMRS type configuration = 1 is set). In this case, Table 7 shows DMRS port combinations designed based on a single TRP.

Therefore, some DMRS port combinations may not be suitable for CoMP (Coordinated Multiple Point) transmission.

For example, when

DMRS port

0,1 is indicated as a combination of DMRS ports, the two ports of

DMRS port

0, 1 should be QCLed. Therefore, in this case, it may be impossible for the DMRS port 0 and the DMRS port 1 to be transmitted in different TRPs.

Therefore, according to the present invention, the terminal which is instructed / set according to the NC-JT state / mode transmission is deleted and some rows not supporting the new table (eg, NC-JT state / mode) other than Table 7 are deleted. Instead, the DMRS port combination based on a row in which a row for the NC-JT state / mode is further defined) may be indicated / configured from the base station.

According to the 5G NR standard of 3GPP Rel-15, only one reference signal (RS) set is defined for one transmission configuration indicator (TCI) state, and only one TCI state is configured for one UE. Is defined to be. Based on the above, the present invention provides a method of signaling two or more RS sets for the TCI state or by setting two or more TCI states to a specific UE so that the specific UE can recognize that it is an NC-JT situation. Suggest.

In this case, two RS sets are provided for the UE, the UE having ambiguity as to which RS set provides QCL information (eg, spatial QCL) of the DMRS associated with the PDSCH scheduled by the corresponding DCI. May have Therefore, the present invention will be described in detail with respect to a signaling method for informing an appropriate or implicit method of which RS set should be applied to a corresponding UE.

In the present invention, the base station may indicate to the terminal a single or multi-DCI based NC-JT by defining / configuring a plurality of RS sets in one TCI state. Subsequently, the base station can provide additional information to the terminal so that the terminal can select the RS set related to the QCL information of the PDSCH scheduled by the DCI among a plurality of configured RS sets. For example, the base station may provide the additional information to the terminal by utilizing CWI and / or DMRS port related field information of the DCI.

Alternatively, in the present invention, the base station may define one RS set in one TCI state and indicate / set a plurality of TCI states to the terminal through a specific DCI. Through this, the base station may indicate to the terminal that the single or multi-DCI based NC-JT. In this case, as a method for selecting a RS set related to the QCL information of the PDSCH scheduled by DCI among the plurality of RS sets configured by the terminal, the existing method of searching for one RS set from the plurality of RS sets described above is applied. Can be.

Therefore, in all the methods proposed below, "the terminal is indicated by one TCI state in which two or more RS sets are defined" is "the terminal is indicated by two or more TCI states through one DCI." Is changed to “selecting one RS set from multiple RS sets” can be extended to “selecting one TCI state from multiple TCI states”.

In all the following methods, at least one of the following signaling methods may be applied to the BS instructing the UE that NC-JT is applied / configured. However, the following example is only one example applicable to the present invention, and the configuration proposed in all the following methods may be equally applied even when the NC-JT is applied / configured according to a signaling method other than the following examples. have.

(1) The base station may indicate a single or multi-DCI based NC-JT to the terminal by defining a plurality of RS sets in one TCI state.

(2) The base station may define one RS set in one TCI state and indicate the terminal to a plurality of TCI states through one DCI, thereby instructing the terminal to be single or multi-DCI based NC-JT.

(3) Random Network Temporary Identifier (RNTI) and C-RNTI (Cell RNTI) for NC-JT are defined differently. Accordingly, the base station may instruct the terminal that the NC-JT is applied / configured by transmitting the scrambled DCI to the terminal using the RNTI for NC-JT instead of the C-RNTI. Correspondingly, when the terminal successfully decodes the received DCI using the RNTI for NC-JT, based on this, the terminal may recognize that the base station has instructed the terminal to NC-JT.

In all the following methods, the DCI (s) paired with the NC-JT may mean a case where each PDSCH scheduled by the DCI (s) overlaps (partially) on T / F resources. .

In the present invention, DMRS port combinations included in the CDM group for each DMRS configuration type may be defined as shown in the following table.

In addition, in the present invention, a table related to the newly proposed DMRS port combination may be defined as shown in the following table. In the following description, unless explicitly stated, the signaling method proposed by the present invention may be implemented based on Table 13 below.

In Table 13, FL and LD may refer to Front Load and Large Delay, respectively. “For single FL DMRS” in a comment item may mean that a corresponding DMRS port combination is applicable when the number of FL DMRS symbols is one. In addition, “CDM group # 1 for LD” in the comment item may mean that the corresponding DMRS ports in the CDM group # 1 are not CDM-F for large delay.

2.1. 제1 방법2.1. First method

When the base station instructs the terminal in the NC-JT state / mode, the terminal corresponds to the DMRS port (s) information of the PDSCH corresponding to the DCI received and successfully decoded and other DCI paired in the NC-JT state / mode It can be expected / assumed to include DMRS port (s) information of the PDSCH.

On the contrary, when the base station instructs the terminal to transmit a single TRP (for example, includes only one RS set in the TCI state) and sets the DMRS configuration type to 1, the terminal expects the above-described Table 6 or Table 7 It is assumed that DMRS port information can be obtained from DCI.

In the present invention, the DMRS port information may include at least one of {CDM group number, rank, DMRS port combination, front-load DMRS symbol number, RS set indicating QCL information of the DMRS port}.

Therefore, when the base station instructs the terminal NC-JT state / mode, the terminal can obtain the DMRS port information from the DCI by expecting / assuming Table 13 above.

In particular, in Table 13, DMRS port (s) for the desired PDSCH represents the DMRS port information of the PDSCH scheduled by the DCI that the current UE successfully decoded. In Table 13, DMRS port (s) for interfering PDSCH indicates DMRS port information of a PDSCH scheduled by a DCI paired with a DCI successfully decoded by the UE and an NC-JT state / mode.

2.2. 제2 방법2.2. 2nd method

When the base station instructs the terminal in the NC-JT state / mode, the terminal may expect / assume that the DMRS port (s) combinations indicated by the DCIs paired in the NC-JT state / mode are symmetric with each other.

More specifically, in Table 13, two DMRS ports combinations are defined by being switched to each other in DMRS port (s) for desired PDSCH and DMRS port (s) for interfering PDSCH. For example, in the case of value = 22 and value = 23, DMRS port combinations (0, 1, 4) and (2, 6) are switched to each other so that DMRS port (s) for desired PDSCH and DMRS port (s) for interfering, respectively. Each defined as PDSCH. Accordingly, when two DCIs paired in the NC-JT state / mode indicate value = 22 and 23, respectively, even if the terminal misses any one of the two DCIs, the terminal succeeds in decoding. From the DCI, the DMRS port (s) of the PDSCH scheduled by the DCI as well as the DMRS port (s) of the PDSCH scheduled by the other DCI can be obtained. As a result, it is not necessary to perform blind detection on the DMRS port (s) scheduled by the DCI missed by the terminal. Therefore, the problem that the performance of the terminal is degraded due to the blind detection of the terminal is also solved.

2.3. 제3 방법2.3. 3rd way

When the base station instructs / sets one TCI state in which two or more RS sets are defined to the terminal and the DMRS port indicated by the DCI transmitted by the base station is included in only one specific CDM group, the terminal may be configured as the CDM group. Based on the information, the RS set providing the QCL information of the DMRS of the PDSCH scheduled by the DCI may be selected.

Here, the CDM group information may be defined as shown in Table 12. In addition, in the present method, it is assumed that CDM groups # 1 / # 2 / # 3 are mapped in order of 1: 1 with RS set #A, #B, and #C set in the TCI state. Accordingly, when the DMRS port indicated to the UE belongs to a specific CDM group, the UE may assume / expect that QCL information of the DMRS port is derived from an RS set mapped to the specific CDM group according to the third method. .

More specifically, in Table 13, #A and #B in RS sets may correspond to two RS sets included in the TCI state, respectively, in order. That is, the base station may set / instruct TCI state = {RS set #A, RS set #B} to the terminal and provide related DMRS port combination information to the terminal through signaling based on Table 13.

In this case, “RS sets” in Table 13 may not be explicitly displayed. In other words, “RS sets” in Table 13 are merely disclosed as separate items for better understanding of the present invention, and the same configuration may be applied even if the corresponding items are not explicitly defined.

In this case, the terminal may determine the RS set to derive the QCL information of the DMRS of the PDSCH scheduled by the DCI based on the CDM group information to which the DMRS ports for the desired PDSCH indicated by the DCI belong. For example, when the DCI indicates value = 4, the UE may acquire QCL information on the assumption that QCL information of DMRS port # 0 of the PDSCH scheduled by the DCI is derived from RS set #A. The UE may acquire QCL information related to the assumption that QCL information of DMRS ports # 2 and # 3 of another PDSCH serving as interference is derived from RS set #B.

As a result, a first DCI of the paired first / second DCIs indicates value = 5 based on the NC-JT mode / state, and the terminal misses the first DCI and only the second DCI. In case of receipt, the UE not only knows that the DMRS port = {2, 3} of the interfering PDSCH from the second DCI, but also knows that the DMRS port is QCLed with the RS set #B. In this case, the UE can improve the interference channel estimation performance by acquiring QCL information for interference channel estimation using DMRS port = {2, 3} and performing channel estimation using the information.

2.4. 제4 방법2.4. 4th method

In the above-described first method, the UE may expect / assuming “DMRS port combination of the maximum applicable interference PDSCH” as the DMRS port (s) of the PDSCH scheduled by another DCI paired in the NC-JT mode / state. Can be. Here, the DMRS port combination of the maximum applicable interference PDSCH may mean a combination with the highest number of ports among the DMRS port combinations to be used by the interference PDSCH. And, the DMRS port combination of the interfering PDSCH may be selected only within the indicated applicable maximum interfering PDSCH DMRS port combination.

In order to implement the above-described first to third methods, coordination between different TRPs should be implemented dynamically. This is because rank information of PDSCHs transmitted by different TRPs is determined dynamically. Therefore, when the coordination between different TRP is not dynamic, the following configuration may be applied.

For example, the maximum possible interference DMRS port combinations between semi-static TRPs are preset, and each TRP dynamically selects a DMRS port subcombination within the combinations to provide PDSCH and DMRS to the UE. Can transmit As a specific example, when the DCI received by the UE indicates value = 20 in Table 13, TRP #A (associated with RS set #A) may transmit PDSCH with DMRS ports # 0 and # 4 to the UE. In addition, the UE may expect / assume that TRP #B (associated with RS set #B) transmits a PDSCH using DMRS ports # 2, # 3, and # 6.

At this time, unlike the expectation / assumption of the terminal, the actual TRP #B may be allowed to transmit the PDSCH using only the DMRS port # 2, # 6. Thus, TRP #B allows to adjust rank without dynamic coordination with TRP #A. In this case, when the UE successfully decodes another DCI related to the PDSCH of TRP #B, the UE does not have (# 2, # 3, # 6) the DMRS port of the PDSCH of the TRP #B (# 2). , # 6).

On the other hand, even if the terminal misses the other DCI, the terminal can find the DMRS port used by the actual TRP #B among the DMRS port # 2, # 3, # 6. Even in this case, the terminal can be sure that the signal is not transmitted using DMRS port # 7, even if the terminal performs blind detection can reduce the complexity of the terminal.

Meanwhile, the above-described technical configuration according to the fourth method may be extended even when the base station instructs the terminal in the NC-JT mode / state but the TRP #B does not transmit the PDSCH to the terminal.

In addition, in the above-described embodiment, TRP #B may allocate DMRS port # 2 and # 6 to the terminal indicated by the NC-JT mode / status, and allocate DMRS port # 3 to the other terminal. In this case, the terminal indicated the NC-JT mode / state may recognize that the DMRS port {# 2, # 6} is utilized from the DCI associated with the PDSCH transmitted in TRP #B. In this case, based on the above operation, the terminal ignores the existence of DMRS port # 3 itself.

Therefore, the following two alternative solutions (alternative solution) can be considered as a solution to the problems that may arise due to this.

-TRP #B does not service DMRS port # 3 to other terminals

-Although the terminal configured with the NC-JT mode / state can recognize that the DMRS port {# 2, # 6} is utilized from the paired DCI, it is expected / assumed that the DMRS port # 3 can also be set to another terminal.

According to the first solution described above, the terminal complexity can be reduced. However, scheduling restriction may be applied from the base station perspective.

On the other hand, according to the second solution, although the limitation is not applied to the scheduling of the base station, there is a disadvantage that the terminal complexity may be increased. However, when considering that the terminal may miss the paired DCI, the operation of the terminal is identical to the operation of the terminal according to the second solution, and the second solution may be more preferable. However, even in this case, the terminal can still assume / expect that the DMRS port # 7 is not used.

In the above-mentioned fourth method, one or more of the following additional modifications may additionally be applied.

2.4.1. 4-1 method

In the same CDM group, a DMRS port combination with a higher rank may be set to always include a DMRS port combination with a lower rank. That is, the combination of DMRS ports in the same CDM group may be configured as a nested structure.

Unlike the above-described example, the TRP # B may transmit the PDSCH based on the DMRS port (# 2, # 6) or the DMRS port # 2 rather than the DMRS ports (# 2, # 3, # 6). To this end, the DMRS table defining the DMRS port combination must support DMRS port (# 2, # 6) or DMRS port # 2. Accordingly, as shown in value = 8 and 12 of Table 13, DMRS port # 2 and DMRS port (# 2, # 6) may be supported, respectively.

The above-described DMRS table of Table 13 may have a nested structure as shown in Tables 14 and 15 below. Table 14 shows a nested structure when the number of front loaded symbols is 1, and Table 15 shows a nested structure when the number of front loaded symbols is 2.

As can be seen from the vertical direction of Table 15, when the rank of CDM group # 1 is fixed to 1, the DMRS ports of CDM group # 2 are (2), (2, 6), (2, 3, 6), As the rank increases to (2, 3, 6, 7), it may be configured to include the DMRS port of the previous rank. The nested structure may be equally applied even when the rank of the CDM group # 1 is 2, 3, or 4.

As can be seen from the horizontal direction in Table 15, when the rank of CDM group # 2 is fixed to 1, the DMRS ports of CDM group # 1 are (0), (0, 4), (0, 1, 4), As the rank increases to (0, 1, 4, 5), it may be configured to include the DMRS port of the previous rank. Such a nested structure may be equally applied even when the rank of the CDM group # 2 is 2, 3, or 4.

As such, when the DMRS port combination has a nested structure, the following effects can be expected.

For example, when the maximum possible DMRS port combination is (2, 3, 6) for the DMRS port (s) for interfering PDSCH, the UE first transmits whether the DMRS port # 3 exists (or is transmitted based on the DMRS port # 3). Whether there is a DMRS or a PDSCH).

In this case, if it is detected that the DMRS port # 3 exists (or if there is a DMRS or PDSCH transmitted based on the DMRS port # 3), the UE always has the DMRS port # 2 and # 6 It can be expected / assumed that there is a (or that there is a DMRS or PDSCH transmitted based on DMRS ports # 2 and # 6). Accordingly, the terminal may not perform blind detection on DMRS ports # 2 and # 6.

On the other hand, if the presence of DMRS port # 3 is not detected (or if the presence of DMRS or PDSCH transmitted based on the DMRS port # 3 is not detected), the UE is in the order of DMRS port # 6 and # 2 Blind detection can be performed. Subsequently, when it is detected that the DMRS port # 6 exists (or when the presence of the DMRS or PDSCH transmitted based on the DMRS port # 6) is detected, the UE always indicates that the DMRS port # 2 is always present (or It can be expected / assumed that there is a DMRS or PDSCH transmitted based on DMRS port # 2. Accordingly, the terminal may not perform blind detection on DMRS port # 2. As a result, according to the present method, the blind detection complexity of the UE with respect to the existence of the DMRS port can be reduced.

2.4.2. 4-2 method

In the same CDM group, according to the number of front load symbols, the DMRS port combination included in the nested structure may be set to change.

For example, if the number of front-loaded symbols is 1, DMRS ports belonging to CDM groups # 1 and # 2 are DMRS port (0), DMRS port (0, 1) / (2), DMRS port ( 2, 3) can be increased in order. This is because, when the number of front-loaded symbols is one, the number of DMRS ports in each CDM group is limited to two.

On the other hand, if the number of front loaded symbols is 2, DMRS ports belonging to CDM groups # 1 and # 2 are DMRS port (0), DMRS port (0, 4), and DMRS port (0, 1, 4), respectively, when the rank increases. DMRS port (0, 1, 4, 5) / (2), DMRS port (2, 6), DMRS port (2, 3, 6), DMRS port (2, 3, 6, 7) Can be. The reason for this is as follows.

In the case of CoMP, different TRPs may simultaneously service one UE. In this case, a specific TRP may be located (physically) far from the terminal point of view. In this case, a delay spread may be set very long by the TRP. Accordingly, when the DMRS port is multiplexed with the CDM-F, performance may be reduced when the DMRS port is separated. In addition, CoMP may be supported when the moving speed of the terminal is less than a certain threshold. Accordingly, in the case of CoMP, the time axis correlation of the channel is very high. That is, CDM-T can provide higher DMRS port separation performance than CDM-F. Therefore, CDM-T may be given priority over CDM-F for the DMRS port.

In addition, if only the DMRS port (0) or DMRS port (0, 4) is instructed to the terminal (that is, the CDM-F is not defined), the terminal is a sample of each DMRS port per one OFDM symbol in one RB As a result, six samples can be obtained. At this time, the interval of the six samples is 2. Therefore, even when frequency selectivity is large due to a very long delay spread (when the channel correlation of the frequency axis is low), the sample interval is small, which may be advantageous in terms of channel estimation performance. On the other hand, in a DMRS port combination including a DMRS port (0, 1), the DMRS port is multiplexed with CDM-F, and the UE can obtain three samples as samples of each DMRS port per OFDM symbol in one RB. have. At this time, the interval of the three samples is four. Therefore, when the frequency selectivity (selectivity) is large as described above, the channel estimation performance is relatively reduced.

2.4.3. 4-3 method

In the above-described method 4-1, when the rank is 1, the DMRS port number may be set to a DMRS port having the smallest index for each CDM group.

The subcarrier index to which the PTRS in one RB is mapped may be determined based on Table 16. Here, the PTRS includes at least one subcarrier on which a DMRS port having the smallest index is mapped based on a DMRS port having the smallest index among the DMRS ports indicated by DCI, a DMRS configuration type, and an upper layer parameter resource elementOffset . Can be defined.

Accordingly, as shown in Table 13, when rank is 1 and DMRS port # 0 and DMRS port # 2 are defined for each CDM group, and a DMRS port having a higher rank has a nested structure including the DMRS port, PTRS is always It may be mapped to DMRS port # 0 or DMRS port # 2. Accordingly, even if the terminal does not detect the DCI paired in the NC-JT mode / state, the PTRS port of the PDSCH scheduled by the missed DCI is limited to correspond to one of DMRS port # 0 or # 2. Can be.

In addition, as in the fourth method described above, even if the DMRS port combination of the interfering PDSCH indicated by the DCI successfully decoded by the UE is different from the DMRS port combination actually transmitted, the DMRS port to which the PTRS port is mapped may not be changed. have.

As a result, the UE can obtain the PTRS port of the interfering PDSCH without additional blind detection. On the other hand, the UE can measure the Common Phase Error (CPE) through the PTRS port of the interfering PDSCH, it can be used to improve the channel estimation performance for the interfering PDSCH.

As a specific example, it is assumed that the DMRS port of the interfering PDSCH indicated by the DCI successfully decoded by the UE is a DMRS port {2, 3, 6}. In this case, the terminal may expect / assume that the PTRS port is always associated with DMRS port # 2 regardless of the actual rank of the interfering PDSCH.

2.5. 제5 방법 2.5. 5th way

When the base station instructs the terminal in the NC-JT mode / state, the terminal is each of the start and length indicator value (SLIV) indicated by the two DCI paired in the NC-JT mode / state or each of the two DCI scheduling It can be expected / assumed that the additional DMRS positions of the PDSCHs are identical.

When the base station instructs the UE in the NC-JT mode / state, PDSCHs transmitted by each TRP may overlap (partially) on T / F resources.

Meanwhile, the number of additional DMRSs (symbols) and a location where the additional DMRSs are mapped may be determined by SLIV. Therefore, if the SLIV indicated by the two DCIs are different, additional DMRS (symbol) numbers and positions may be determined differently from each other.

In this case, as a method for protecting additional DMRSs for each PDSCH, the base station may transmit rate matching or puncturing a PDSCH region overlapping the additional DMRS.

For example, the location of additional DMRS of PDSCH scheduled by DCI # 0 is symbol index (3, 6, 9), while DCI # 1 (DCI paired with DCI # 0 and NC-JT mode / state) is scheduled. Assume that the position of additional DMRS of PDSCH is symbol index (3, 5, 8, 11). In this case, the two PDSCHs may be rate matched (or punctured) with respect to the OFDM symbol indexes (3, 5, 6, 8, 9, 11) and transmitted. Accordingly, throughput may be greatly reduced due to high signaling overhead.

In addition, when the terminal misses another DCI, ambiguity may occur for additional DMRS positions of the PDSCH scheduled by the missed DCI. Accordingly, the terminal cannot perform or consider rate matching (or puncturing).

Accordingly, the terminal has the same number of additional DMRS positions and / or symbols in each SLIV (Start and Length Indicator Value) indicated by two DCIs paired in NC-JT mode / state or in each PDSCH scheduled by the two DCIs. It can be expected / assumed, and accordingly the base station may schedule a PDSCH to the terminal.

In the above-described configuration, the case in which a plurality of DCIs (eg, at least two DCIs scheduling different PDSCHs) is allocated to one UE is mainly described. The same can be extended to (Multi User) case. More specifically, the base station may transmit to each terminal that the MU situation through the DCI transmitted to each terminal, each terminal is scheduled for other terminal (s) other than PDSCH scheduled for each terminal based on the received DCI It can be appreciated that the PDSCH is present. Accordingly, each terminal may receive information on an interference channel and receive a corresponding PDSCH with higher reliability.

The base station may (i) schedule one or more physical downlink shared channel (PDSCH) to the terminal, and (ii) transmit downlink control information (DCI) including a plurality of transmission configuration indication (TCI) states. (S1610, S1810). In this case, one TCI state may be set to be associated with one reference signal (RS) set.

In response, the UE may (i) schedule one or more PDSCHs, and (ii) receive a DCI including a plurality of TCI states from a base station (or a network) (S1610, S1710).

On the basis of the assumption that the additional demodulation reference signal (DMRS) position for the first PDSCH scheduled by the DCI and the additional DMRS position for the second PDSCH are the same (S1620), The first PDSCH may be received from a base station (or a network) (S1630 and S1720). In this case, the terminal may receive the first PDSCH from the first TRP connected to the base station.

Here, the second PDSCH may correspond to a PDSCH which is partially or partially overlapped with the first PDSCH in the time domain.

In particular, according to an embodiment, the second PDSCH may be scheduled to the terminal. In this case, the second PDSCH may be scheduled by the DCI scheduling the first PDSCH or by a separate DCI different from the DCI. In addition, the terminal may receive the second PDSCH from a second TRP connected to the base station.

In response, the base station may transmit a plurality of PDSCHs including the first PDSCH and the second PDSCH (S1630 and S1820). For example, the base station may transmit the plurality of PDSCHs to different terminals or to the same terminal. In this case, the plurality of PDSCHs may be scheduled to overlap all or part of the time domain, and in particular, additional DMRS positions for the plurality of PDSCHs may be identically scheduled to each other.

The terminal may decode the received PDSCHs and thereby obtain related data information (S1640 and S1730).

In the above-described configuration, the additional DMRS location for the first PDSCH may include one or more DMRS symbols except for a front-loaded DMRS symbol during the symbol period of the first PDSCH. For example, the additional DMRS location for the first PDSCH may include the last symbol of the symbol period of the first PDSCH or one or more symbols after the third in the symbol period of the first PDSCH.

In addition, the front-loaded DMRS symbol during the symbol period of the first PDSCH may include one or two DMRS symbols. Accordingly, the front-loaded DMRS symbol for the first PDSCH may include only the first symbol in the symbol period of the first PDSCH, or may include the first symbol and the second symbol.

As described above, the terminal may receive the second PDSCH from the base station. In this case, the second PDSCH may be scheduled by the DCI or another DCI.

The DCI scheduling the first PDSCH may include (i) DMRS information for the first PDSCH and (2) DMRS information for the second PDSCH. Accordingly, the UE may acquire / assume (i) DMRS information for the first PDSCH and (2) DMRS information for the second PDSCH through the DCI.

In the present invention, the DMRS information may include at least one of the following information.

Number of Code Division Multiplexing (CDM) groups for the corresponding PDSCH.

A rank for the corresponding PDSCH

A combination of DMRS port numbers for the corresponding PDSCH

Number of front-loaded DMRS symbols for the corresponding PDSCH

RS set associated with DMRS for corresponding PDSCH

Accordingly, based on the combination of (i) a combination of DMRS port numbers for the first PDSCH and (ii) a maximum DMRS port number for the second PDSCH obtained from the DCI, the terminal selects the first PDSCH. It can receive from the base station. In particular, the terminal can estimate the interference channel for the first PDSCH using the information obtained from the DCI, and can receive the first PDSCH based on the interference channel estimation.

According to the present invention, based on one or more DMRS port numbers for the first PDSCH indicated by the DCI included in a specific Code Division Multiplexing (CDM) group, the terminal is configured to receive the plurality of TCI states. The first PDSCH may be received using quasi co located (QCL) information derived from an RS set associated with one TCI state. Accordingly, the terminal may receive the first PDSCH using (i) the interference channel estimated for the first PDSCH based on the information obtained from the DCI, and (ii) the derived QCL information.

In this case, the combination of the maximum DMRS port numbers for the second PDSCH may be configured to have a nested structure. More specifically, as described above in Tables 14 to 15, the nested structure according to the present invention corresponds to the rank N in which the combination of the first maximum DMRS port number corresponding to the rank M is smaller than the rank M. It may mean a structure configured to include a combination of the second maximum DMRS port number.

In this case, the combination of the maximum DMRS port number for the second PDSCH, the combination of the third maximum DMRS port number corresponding to rank 1, the smallest DMRS port in the corresponding Code Division Multiplexing (CDM) group It can be set to include a number.

In the present invention, all the above-described examples (in particular, those described above based on Figs. 16 to 18) may be implemented in combination / combination with each other as long as they are not compatible. In other words, the terminal and the base station according to the present invention may perform their combined / combined operation as long as all the examples described above (in particular, the above-described examples based on FIGS. 16 to 18) are not compatible.

It is obvious that examples of the proposed schemes described above may also be regarded as a kind of proposed schemes as they may be included as one of the implementation methods of the present invention. In addition, although the above-described proposed schemes may be independently implemented, some proposed schemes may be implemented in a combination (or merge) form. Information on whether the proposed methods are applied (or information on the rules of the proposed methods) may be defined so that the base station informs the UE through a predefined signal (eg, a physical layer signal or a higher layer signal). have.

3. 장치 구성3. Device Configuration

19 is a diagram illustrating a configuration of a terminal and a base station in which the proposed embodiment can be implemented. The terminal and the base station illustrated in FIG. 19 operate to implement the above-described downlink signal transmission / reception method between the terminal and the base station.

A UE 1001 may operate as a transmitting end in uplink and a receiving end in downlink. In addition, the base station eNB or gNB 1100 may operate as a receiver in uplink and as a transmitter in downlink.

That is, the terminal and the base station may include

transmitters

1010 and 1110 and

receivers

1020 and 1120, respectively, to control transmission and reception of information, data and / or messages. Or

antennas

1030 and 1130 for transmitting and receiving messages.

In addition, the terminal and the base station each include

processors

1040 and 1140 for performing the above-described embodiments of the present invention. The

processor

1040, 1140 may be configured to control the

memory

1050, 1150 and / or the

transmitters

1010, 1110 and / or the

receivers

1020, 1120 to implement the above-described / proposed procedures and / or methods. Can be.

In one example,

processors

1040 and 1140 include communication modems designed to implement wireless communication technology (eg, LTE, NR). The

memories

1050 and 1150 are connected to the

processors

1040 and 1140 and store various information related to the operation of the

processors

1040 and 1140. For example, the

memory

1050, 1150 may include software code that includes instructions for performing some or all of the processes controlled by the

processor

1040, 1140, or for performing the procedures and / or methods described / proposed above. Can be stored. The

transmitters

1010, 1110 and / or

receivers

1020, 1120 are connected with the

processors

1040, 1140 and transmit and / or receive wireless signals. Here, the

processors

1040 and 1140 and the

memories

1050 and 1150 may be part of a processing chip (eg, a System on a Chip, SoC).

The transmitter and the receiver included in the terminal and the base station include a packet modulation and demodulation function, a high speed packet channel coding function, an orthogonal frequency division multiple access (OFDMA) packet scheduling, and a time division duplex (TDD) for data transmission. Packet scheduling and / or channel multiplexing may be performed. In addition, the terminal and the base station of FIG. 19 may further include a low power radio frequency (RF) / intermediate frequency (IF) unit.

The device shown in FIG. 20 may be a user equipment (UE) and / or a base station (eg, eNB or gNB) adapted to perform the above-described mechanism, or any device performing the same task.

As shown in FIG. 20, the apparatus may include a digital signal processor (DSP) / microprocessor 2210 and a radio frequency (RF) module (transceiver) 2235. The DSP / microprocessor 2210 is electrically connected to the transceiver 2235 to control the transceiver 2235. The device may be adapted to a power management module 2205, a battery 2255, a display 2215, a keypad 2220, a SIM card 2225, a memory device 2230, an antenna 2240, and a speaker (depending on the designer's choice). 2245 and input device 2250.

In particular, FIG. 20 may represent a terminal including a receiver 2235 configured to receive a request message from a network and a transmitter 2235 configured to transmit timing transmit / receive timing information to the network. Such a receiver and a transmitter may constitute a transceiver 2235. The terminal may further include a processor 2210 connected to a transceiver (receiver and transmitter) 2235.

20 may also show a network device including a transmitter 2235 configured to transmit a request message to a terminal and a receiver 2235 configured to receive transmission and reception timing information from the terminal. The transmitter and receiver may configure transceiver 2235. The network further includes a processor 2210 coupled to the transmitter and the receiver. The processor 2210 may calculate a latency based on the transmission / reception timing information.

Accordingly, a processor included in a terminal (or a communication device included in the terminal) and a processor included in a base station (or a communication device included in the base station) according to the present invention may control a corresponding memory and operate as follows. have.

In the present invention, the terminal, at least one radio frequency (RF) module; At least one processor; And at least one memory operatively connected to the at least one processor, and storing instructions that, when executed, cause the at least one processor to perform the following operation. In this case, the communication device included in the terminal may be configured to include the at least one processor and the at least one memory, and the communication device includes the at least one RF module or the at least one RF. It may be configured to be connected to the at least one RF module without a module.

At least one processor included in the terminal (or at least one processor of the communication apparatus included in the terminal) controls the at least one RF module to (i) establish one or more physical downlink shared channel (PDSCH). And (ii) receive downlink control information (DCI) including a plurality of Transmission Configuration Indication (TCI) states. At this time, one TCI state may be associated with one reference signal (RS) set. In addition, at least one processor (or at least one processor of a communication device included in the terminal) included in the terminal controls the at least one RF module to add the first PDSCH scheduled by the DCI. (additional) A demodulation reference signal (DMRS) position can be configured to receive the first PDSCH, assuming that the additional DMRS position for the second PDSCH is the same.

The terminal (or a communication device included in the terminal) may be configured to communicate with at least one of a mobile terminal, a network, and an autonomous vehicle other than the vehicle including the terminal.

In the present invention, a base station comprises: at least one radio frequency (RF) module; At least one processor; And at least one memory operatively connected to the at least one processor, and storing instructions that, when executed, cause the at least one processor to perform the following operation. In this case, the communication device included in the base station may be configured to include the at least one processor and the at least one memory, and the communication device includes the at least one RF module or the at least one RF. It may be configured to be connected to the at least one RF module without a module.

At least one processor included in the base station (or at least one processor of the communication apparatus included in the base station) controls the at least one RF module to provide a terminal with (i) one or more physical downlink shared channels ( PDSCH) and (ii) transmit downlink control information (DCI) including a plurality of Transmission Configuration Indication (TCI) states. At this time, one TCI state may be associated with one reference signal (RS) set. In addition, at least one processor (or at least one processor of a communication device included in the base station) included in the base station controls the at least one RF module to add for the first PDSCH scheduled by the DCI. (additional) to transmit the first PDSCH and the second PDSCH to one or more terminals including the terminal based on the same demodulation reference signal (DMRS) position and the additional DMRS position for the second PDSCH; Can be configured.

Meanwhile, in the present invention, the terminal is a personal digital assistant (PDA), a cellular phone, a personal communication service (PCS) phone, a global system for mobile (GSM) phone, a wideband CDMA (WCDMA) phone, and an MBS. A Mobile Broadband System phone, a Hand-Held PC, a Notebook PC, a Smart Phone, or a Multi Mode-Multi Band (MM-MB) terminal may be used.

Here, a smart phone is a terminal that combines the advantages of a mobile communication terminal and a personal portable terminal, and may mean a terminal incorporating data communication functions such as schedule management, fax transmission and reception, etc. which are functions of a personal portable terminal. have. In addition, a multimode multiband terminal can be equipped with a multi-modem chip to operate in both portable Internet systems and other mobile communication systems (e.g., code division multiple access (CDMA) 2000 systems, wideband CDMA (WCDMA) systems, etc.). Speak the terminal.

Embodiments of the invention may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

In the case of a hardware implementation, a method according to embodiments of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors and the like can be implemented.

In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, procedure, or function that performs the functions or operations described above. For example, the software code may be stored in the

memory units

1050 and 1150 and driven by the

processors

1040 and 1140. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

The above-described communication device includes a base station, a network node, a transmission terminal, a reception terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, It may be a robot, an Augmented Reality (AR) device, a Virtual Reality (VR) device, or other device.

For example, the terminal may be a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), navigation, a slate PC, a tablet. It may include a tablet PC, an ultrabook, a wearable device (eg, a smartwatch, a glass glass, a head mounted display), and the like. . For example, a drone may be a vehicle in which humans fly by radio control signals. For example, the HMD may be a display device worn on the head. For example, the HMD can be used to implement VR or AR.

The invention can be embodied in other specific forms without departing from the technical idea and essential features of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention. In addition, the claims may be incorporated into claims that do not have an explicit citation relationship in the claims, or may be incorporated into new claims by amendment after filing.

Embodiments of the present invention can be applied to various wireless access systems. Examples of various radio access systems include 3rd Generation Partnership Project (3GPP) or 3GPP2 systems. Embodiments of the present invention can be applied not only to the various radio access systems, but also to all technical fields to which the various radio access systems are applied. Furthermore, the proposed method can be applied to mmWave communication system using ultra high frequency band.

In addition, embodiments of the present invention may be applied to various applications such as a free running vehicle and a drone.

Claims

In a method for receiving a downlink signal from a terminal in a wireless communication system,

(i) schedule one or more physical downlink shared channel (PDSCH), and (ii) receive downlink control information (DCI) including a plurality of Transmission Configuration Indication (TCI) states,

One TCI state is associated with one reference signal (RS) set; And

Receiving the first PDSCH under the assumption that an additional demodulation reference signal (DMRS) position for a first PDSCH scheduled by the DCI and an additional DMRS position for a second PDSCH are the same The downlink signal receiving method of the terminal.
The method of claim 1,

The additional DMRS location for the first PDSCH is

And at least one DMRS symbol except for a front-loaded DMRS symbol during a symbol period of the first PDSCH.
The method of claim 2,

The front-loaded DMRS symbol during the symbol period of the first PDSCH, one or two DMRS symbols, the downlink signal receiving method of the terminal.
The method of claim 1,

The downlink signal receiving method of the terminal,

Further comprising receiving the second PDSCH,

The second PDSCH is scheduled by the DCI or another DCI, downlink signal receiving method of a terminal.
The method of claim 1,

Based on the DCI including the plurality of TCI states, the terminal recognizes that the first PDSCH and the second PDSCH are scheduled for the terminal,

The first PDSCH and the second PDSCH overlap all or part of the time domain, downlink signal reception method of a terminal.
The method of claim 1,

Based on the DCI including the plurality of TCI states, the UE receives the first PDSCH and the second PDSCH based on a Non-Coherent Joint Transmission (NC-JT) mode. Recognizing the downlink signal reception method of the terminal.
The method of claim 6,

Based on the DCI including the plurality of TCI states, DMRS port information associated with the DCI is obtained based on a table configured for the NC-JT mode.
The method of claim 1,

The DCI is,

(i) DMRS information for the first PDSCH, and

(2) A method for receiving downlink signal from a terminal, including DMRS information for the second PDSCH.
The method of claim 8,

The DMRS information is

Number of Code Division Multiplexing (CDM) groups for the corresponding PDSCH,

A rank for the corresponding PDSCH,

A combination of DMRS port numbers for the corresponding PDSCH,

Number of front-loaded DMRS symbols for the corresponding PDSCH, or

And at least one of an RS set associated with a DMRS for the corresponding PDSCH.
The method of claim 1,

Based on (i) a combination of DMRS port numbers for the first PDSCH and (ii) a maximum DMRS port number for the second PDSCH, obtained from the DCI, the terminal receives the first PDSCH, Downlink signal receiving method of a terminal.
The method of claim 10,

The combination of the maximum DMRS port number for the second PDSCH is

The combination of the first maximum DMRS port number corresponding to rank M is set to include a combination of the second maximum DMRS port number corresponding to rank N smaller than rank M,

M, N is a natural number, the downlink signal receiving method of the terminal.
The method of claim 11,

The combination of the maximum DMRS port number for the second PDSCH is

And a combination of the third maximum DMRS port numbers corresponding to rank 1 is configured to include the smallest DMRS port number in a corresponding Code Division Multiplexing (CDM) group.
The method of claim 1,

Based on one or more DMRS port numbers for the first PDSCH indicated by the DCI included in a specific Code Division Multiplexing (CDM) group, the UE is in a TCI state of one of the plurality of TCI states. And receiving the first PDSCH using QCL (Quasi Co Located) information derived from a set of RSs associated with the downlink signal.
The method of claim 1,

The first PDSCH and the second PDSCH overlap all or part of the time domain, downlink signal reception method of a terminal.
A terminal for receiving a downlink signal in a wireless communication system,

At least one radio frequency (RF) module;

At least one processor; And

At least one memory operatively coupled to the at least one processor, the at least one memory storing instructions that, when executed, cause the at least one processor to perform a particular operation;

The specific action is:

(i) schedule one or more physical downlink shared channel (PDSCH), and (ii) receive downlink control information (DCI) including a plurality of Transmission Configuration Indication (TCI) states,

One TCI state is associated with one reference signal (RS) set; And

Receiving the first PDSCH under the assumption that an additional demodulation reference signal (DMRS) position for a first PDSCH scheduled by the DCI and an additional DMRS position for a second PDSCH are the same Terminal.
The method of claim 15,

The terminal is in communication with at least one of a mobile terminal, a network, and an autonomous vehicle other than the vehicle including the terminal.
In the base station for transmitting a downlink signal in a wireless communication system,

At least one radio frequency (RF) module;

At least one processor; And

At least one memory operatively coupled to the at least one processor, the at least one memory storing instructions that, when executed, cause the at least one processor to perform a particular operation;

The specific action is:

(I) scheduling at least one physical downlink shared channel (PDSCH), and (ii) transmitting downlink control information (DCI) including a plurality of transmission configuration indication (TCI) states to a terminal,

One TCI state is associated with one reference signal (RS) set; And

Based on the fact that an additional demodulation reference signal (DMRS) position for a first PDSCH scheduled by the DCI and an additional DMRS position for a second PDSCH are identical to one or more terminals including the UE. And transmitting the first PDSCH and the second PDSCH.
The method of claim 17,

At least one first DMRS port number and the first number for the first PDSCH based on the first PDSCH being transmitted through a first TRP and the second PDSCH being transmitted through a second TRP One or more second DMRS port numbers for 2 PDSCHs are included in different Code Division Multiplexing (CDM) group numbers.