WO2020032735A1

WO2020032735A1 - Method and device for transmitting/receiving physical broadcast channel (pbch) in wireless communication system

Info

Publication number: WO2020032735A1
Application number: PCT/KR2019/010153
Authority: WO
Inventors: 김재형; 김선욱; 박창환; 신석민; 안준기; 양석철; 황승계
Original assignee: 엘지전자 주식회사
Priority date: 2018-08-09
Filing date: 2019-08-09
Publication date: 2020-02-13

Abstract

The present specification provides a method for transmitting a PBCH by a base station in a wireless communication system, the method comprising: mapping a PBCH to a plurality of resource elements (REs); and transmitting the PBCH to a terminal on the plurality of REs, wherein the PBCH mapping comprises copying PBCH orthogonal frequency division multiplexing (OFDM) symbols included in PBCH repetition into an LTE control region, in consideration of a frame structure type.

Description

Method and apparatus for transmitting / receiving physical broadcast channel (PBCH) in wireless communication system

The present disclosure relates to a wireless communication system, and more particularly, to a PBCH transmission / reception method for supporting standalone operation of LTE-MTC (Machine Type Communication) and an apparatus supporting the same.

Mobile communication systems have been developed to provide voice services while ensuring user activity. However, the mobile communication system has expanded not only voice but also data service, and the explosive increase in traffic causes resource shortages and users require faster services. Therefore, a more advanced mobile communication system is required. .

The requirements of the next generation of mobile communication systems can support the massive explosive data traffic, the dramatic increase in transmission rate per user, the large increase in the number of connected devices, the very low end-to-end latency, and the high energy efficiency. It should be possible. For this purpose, Dual Connectivity, Massive Multiple Input Multiple Output (MIMO), In-band Full Duplex, Non-Orthogonal Multiple Access (NOMA), Super Wide Various technologies such as wideband support and device networking have been studied.

An object of the present specification is to provide a method for transmitting / receiving a PBCH in a wireless communication system.

Technical problems to be achieved in the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

The present specification provides a method for transmitting a physical broadcast channel (PBCH) by a base station supporting machine type communication (MTC) in a wireless communication system.

Specifically, a method for transmitting a physical broadcast channel (PBCH) performed by a base station includes: mapping a PBCH to a plurality of resource elements (REs); And transmitting the PBCH to the UE on the plurality of REs, wherein the PBCH mapping includes PBCH orthogonal frequency division included in a PBCH repetition in consideration of a frame structure type. Copying multiplexing symbols into an LTE control region.

In the present specification, all or part of the PBCH OFDM symbols are copied to the LTE control region according to a PBCH repetition pattern determined according to the frame structure type.

In addition, in the present specification, the PBCH OFDM symbols are characterized by consisting of four OFDM symbols.

Also, in the present specification, the PBCH repetition is performed in a first subframe and a second subframe.

Also, in the present specification, when the frame structure type is frame structure type 1, the first subframe is subframe 0, the second subframe is subframe 9, and the frame structure type is frame structure type 2 In this case, the first subframe is subframe 0, and the second subframe is subframe five.

Also, in the present specification, when the frame structure type is frame structure type 1, all of the PBCH OFDM symbols are copied to the LTE control region, and when the frame structure type is frame structure type 2, the PBCH OFDM symbol Some of them are copied to the LTE control region.

In the present specification, the PBCH OFDM symbols are copied to at least one of the LTE control region of the first subframe or the LTE control region of the second subframe.

Also, in the present specification, the PBCH OFDM symbols included in the repeated PBCH repetition after the LTE control region may be the same interval as the PBCH OFDM symbols copied to the LTE control region.

In this specification, the reference signal RS may be used to improve MPDCCH / PDSCH channel estimation performance, or may be used for improving measurement accuracy such as RSRP / RSRQ.

In addition, the present specification may use the LTE control region for the purpose of transmitting the MPDCCH / PDSCH data resource element (data RE).

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

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide embodiments of the present invention and together with the description, describe the technical features of the present invention.

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

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

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

4 is a diagram illustrating an example of an LTE radio frame structure.

5 illustrates an example of a resource grid for a downlink slot.

6 shows an example of a downlink subframe structure.

7 shows an example of an uplink subframe structure.

8 shows an example of frame structure type 1. FIG.

9 illustrates another example of the frame structure type 2. FIG.

10 shows an example of a random access symbol group.

11 is an example of an initial access procedure of an NB-IoT.

12 is an example of a random access procedure of the NB-IoT.

13 shows a structure of a random access symbol group.

14 shows an example of a DRX scheme in an idle state and / or an inactive state.

15 shows an example of a DRX configuration and indication procedure for an NB-IoT terminal.

16 shows one example of a cycle of DRX.

FIG. 17A illustrates an example of a narrowband operation, and FIG. 17B illustrates an example of repetition having RF retuning.

18 illustrates physical channels that can be used for MTC and a general signal transmission method using the same.

FIG. 19 (a) shows an example of a frequency error estimation method for the repetition pattern, general CP, and repeated symbols for subframe # 0 in FDD, and FIG. An example of transmission is shown.

20 is a diagram illustrating an example of scheduling for each of MTC and legacy LTE.

21 shows a general system for a system information acquisition procedure.

22 illustrates a contention based random access procedure.

23 shows an example of a DRX scheme in an idle state and / or an inactive state.

24 shows an example of a DRX configuration and indication procedure for an MTC terminal.

25 shows one example of a DRX cycle.

FIG. 26 shows a diagram in which 4 PBCH repetitions are applied in eMTC. FIG.

FIG. 27 shows a first example (example 1) of a method for extending a PBCH to an LTE control region for an sMTC UE proposed in the present invention.

28 shows a second example (example 2) of a method of extending a PBCH to an LTE control region for an sMTC UE proposed in the present invention.

29 shows a third example (example 3) of a method of extending a PBCH to an LTE control region for an sMTC UE proposed in the present invention.

30 illustrates a wireless communication device according to some embodiments of the present disclosure.

31 is another example of a block diagram of a wireless communication device according to some embodiments of the present disclosure.

32 shows another example of a wireless device to which the present invention is applied.

33 illustrates a signal processing circuit for a transmission signal.

34 illustrates a portable device applied to the present invention.

35 illustrates an XR device to which the present invention is applied.

36 is a flowchart illustrating a method of receiving an MPDCCH by a terminal.

37 is a flowchart illustrating a method of transmitting an MPDCCH by a base station.

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. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention.

In this specification, a base station has a meaning as a terminal node of a network that directly communicates with a terminal. 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, it is apparent that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station (BS)' may be replaced by terms such as a fixed station, a Node B, an evolved-NodeB (eNB), a base transceiver system (BTS), an access point (AP), and the like. . In addition, a 'terminal' may be fixed or mobile, and may include a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), and an AMS ( Advanced Mobile Station (WT), Wireless Terminal (WT), Machine-Type Communication (MTC) device, Machine-to-Machine (M2M) device, Device-to-Device (D2D) device, etc. may be replaced.

Hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station.

Specific terms used in the following description 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.

The following techniques are 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 NOMA It can be used in various radio access systems such as non-orthogonal multiple access. CDMA may be implemented by a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented in a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), or the like. UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of an evolved UMTS (E-UMTS) using E-UTRA, and employs OFDMA in downlink and SC-FDMA in uplink. LTE-A (advanced) is an evolution of 3GPP LTE.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802, 3GPP and 3GPP2. That is, steps or parts which are not described to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the above documents. In addition, all terms disclosed in the present document can be described by the above standard document.

For clarity, the following description focuses on 3GPP LTE / LTE-A, but the technical features of the present invention are not limited thereto.

<5G 시나리오><5G scenario>

The three key requirements areas for 5G are: (1) Enhanced Mobile Broadband (eMBB) area, (2) massive Machine Type Communication (mMTC) area, and (3) ultra-reliability and It includes the area of Ultra-reliable and Low Latency Communications (URLLC).

Some use cases may require multiple areas for optimization, and other use cases may be focused on only one key performance indicator (KPI). 5G supports these various use cases in a flexible and reliable way.

eMBB goes far beyond basic mobile Internet access and covers media and entertainment applications in rich interactive work, cloud or augmented reality. Data is one of the key drivers of 5G and may not see dedicated voice services for the first time in the 5G era. In 5G, voice is expected to be treated as an application simply using the data connection provided by the communication system. The main reasons for the increased traffic volume are the increase in content size and the increase in the number of applications requiring high data rates. Streaming services (audio and video), interactive video and mobile Internet connections will become more popular as more devices connect to the Internet. Many of these applications require always-on connectivity to push real-time information and notifications to the user. Cloud storage and applications are growing rapidly in mobile communication platforms, which can be applied to both work and entertainment. And, cloud storage is a special use case that drives the growth of uplink data rates. 5G is also used for remote work in the cloud and requires much lower end-to-end delays to maintain a good user experience when tactile interfaces are used. Entertainment For example, cloud gaming and video streaming are another key factor in increasing the need for mobile broadband capabilities. Entertainment is essential in smartphones and tablets anywhere, including in high mobility environments such as trains, cars and airplanes. Another use case is augmented reality and information retrieval for entertainment. Here, augmented reality requires very low latency and instantaneous amount of data.

In addition, one of the most anticipated 5G use cases relates to the ability to seamlessly connect embedded sensors in all applications, namely mMTC. By 2020, potential IoT devices are expected to reach 20 billion. Industrial IoT is one of the areas where 5G plays a major role in enabling smart cities, asset tracking, smart utilities, agriculture and security infrastructure.

URLLC includes new services that will transform the industry through ultra-reliable / low latency available links such as remote control of key infrastructure and self-driving vehicles. The level of reliability and latency is essential for smart grid control, industrial automation, robotics, drone control and coordination.

Next, a number of use cases will be described in more detail.

5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) as a means of providing streams that are rated at hundreds of megabits per second to gigabits per second. This high speed is required to deliver TVs in 4K and higher resolutions (6K, 8K and higher) as well as virtual and augmented reality. Virtual Reality (AVR) and Augmented Reality (AR) applications include nearly immersive sporting events. Certain applications may require special network settings. For example, for VR games, game companies may need to integrate core servers with network operator's edge network servers to minimize latency.

Automotive is expected to be an important new driver for 5G, with many use cases for mobile communications to vehicles. For example, entertainment for passengers requires simultaneous high capacity and high mobility mobile broadband. This is because future users will continue to expect high quality connections regardless of their location and speed. Another use case in the automotive sector is augmented reality dashboards. It identifies objects in the dark above what the driver sees through the front window and overlays information that tells the driver about the distance and movement of the object. In the future, wireless modules enable communication between vehicles, information exchange between the vehicle and the supporting infrastructure, and information exchange between the vehicle and other connected devices (eg, devices carried by pedestrians). The safety system guides alternative courses of action to help drivers drive safer, reducing the risk of an accident. The next step will be a remotely controlled or self-driven vehicle. This is very reliable and requires very fast communication between different self-driving vehicles and between automobiles and infrastructure. In the future, self-driving vehicles will perform all driving activities, and drivers will focus on traffic anomalies that the vehicle itself cannot identify. The technical requirements of self-driving vehicles require ultra-low latency and ultra-fast reliability to increase traffic safety to an unachievable level.

Smart cities and smart homes, referred to as smart societies, will be embedded in high-density wireless sensor networks. The distributed network of intelligent sensors will identify the conditions for cost and energy-efficient maintenance of the city or home. Similar settings can be made for each hypothesis. Temperature sensors, window and heating controllers, burglar alarms and appliances are all connected wirelessly. Many of these sensors are typically low data rates, low power and low cost. However, for example, real time HD video may be required in certain types of devices for surveillance.

The consumption and distribution of energy, including heat or gas, is highly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect information and act accordingly. This information can include the behavior of suppliers and consumers, allowing smart grids to improve the distribution of fuels such as electricity in efficiency, reliability, economics, sustainability of production and in an automated manner. Smart Grid can be viewed as another sensor network with low latency.

The health sector has many applications that can benefit from mobile communications. The communication system can support telemedicine, providing clinical care at a distance. This can help reduce barriers to distance and improve access to health care services that are not consistently available in remote rural areas. It is also used to save lives in critical care and emergencies. A mobile communication based wireless sensor network can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Thus, the possibility of replacing the cables with reconfigurable wireless links is an attractive opportunity in many industries. However, achieving this requires that the wireless connection operates with similar cable delay, reliability, and capacity, and that management is simplified. Low latency and very low error probability are new requirements that need to be connected in 5G.

Logistics and freight tracking are important examples of mobile communications that enable the tracking of inventory and packages from anywhere using a location-based information system. The use of logistics and freight tracking typically requires low data rates but requires wide range and reliable location information.

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.

<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.

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.

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.

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 ™, Radio Frequency Identification (RFID), Infrared Data Association (IrDA), ZigBee, and Near Field Communication (NFC).

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.

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.

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.

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 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.

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.

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.

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.

<LTE 시스템 일반><LTE System General>

4 is a diagram illustrating an example of an LTE radio frame structure.

In FIG. 4, a radio frame includes 10 subframes. The subframe includes two slots in the time domain. The time for transmitting one subframe is defined as a transmission time interval (TTI). For example, one subframe may have a length of 1 millisecond (ms), and one slot may have a length of 0.5 ms. One slot includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols in the time domain. Since 3GPP LTE uses OFDMA in downlink, an OFDM symbol is for indicating one symbol period. An OFDM symbol may also be referred to as an SC-FDMA symbol or symbol period. A resource block (RB) is a resource allocation unit and includes a plurality of consecutive subcarriers in one slot. The structure of the radio frame is exemplary. Accordingly, the number of subframes included in the radio frame, the number of slots included in the subframe, or the number of OFDM symbols included in the slot may be modified in various ways.

5 illustrates an example of a resource grid for a downlink slot.

In FIG. 5, the downlink slot includes a plurality of OFDM symbols in the time domain. In this specification, as one example, one downlink slot includes seven OFDM symbols, and one resource block RB includes 12 subcarriers in the frequency domain. However, the present invention is not limited only to the above examples. Each element of the resource grid is referred to as a resource element (RE). One RB contains 12x7 REs. The number NDL of RBs included in the downlink slot depends on the downlink transmission bandwidth. The structure of the uplink slot may be the same as that of the downlink slot.

6 shows an example of a downlink subframe structure.

In FIG. 6, up to three OFDM symbols located in the first half of the first slot in the subframe are control regions (control regions) to which control channels are allocated. The remaining OFDM symbols correspond to data regions to which PDSCHs are allocated. Examples of downlink control channels used in 3GPP LTE include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), and the like. The PCFICH is transmitted in the first OFDM symbol of a subframe and carries information on OFDM symbols used for transmission of control channels within the subframe. The PHICH is a response to uplink transmission and carries an HARQ acknowledgment (ACK) / negative-acknowledgment (NACK) signal. Control information transmitted on the PDCCH is referred to as downlink control information (DCI). The DCI includes uplink or downlink scheduling information or uplink transmission (Tx) power control command for certain UE groups.

The PDCCH includes a transport format and resource allocation of a downlink shared channel (DL-SCH), resource allocation information of an uplink shared channel (UL-SCH), paging information for a paging channel (PCH), and a system for a DL-SCH. Information, resource allocation of upper layer control messages such as random access response transmitted on PDSCH, set of Tx power control commands for individual UEs in an arbitrary UE group, voice over IP (VoIP) Can carry Tx power control commands, activations, etc. A plurality of PDCCHs may be transmitted in the control region. The UE may monitor the plurality of PDCCHs. The PDCCH is transmitted on the aggregation of one or several consecutive CCEs (control channel elements). The CCE is a logical allocation unit used to provide a PDCCH with a coding rate based on the state of a radio channel. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH and the number of bits of available PDCCH are determined according to the correlation between the number of CCEs and the coding rate provided by the CCEs. The BS determines the PDCCH format according to the DCI to be transmitted to the UE, and attaches a cyclic redundancy check (CRC) to the control information. The CRC is masked with a unique identifier (referred to as a radio network temporary identifier (RNTI)) depending on the owner or use of the PDCCH. If the PDCCH is for a particular UE, a unique identifier (eg, C-RNTI (Cell-RNTI)) for that UE may be masked in the CRC. As another example, if the PDCCH is for a paging message, a paging indicator identifier (eg, paging-RNTI) may be masked to the CRC. If the PDCCH is for system information (more specifically, a system information block (SIB) to be described later), the system information identifier and the system information RNTI (SI-RNTI) may be masked to the CRC. To indicate a random access response that is a response to the transmission of the preamble, a random access-RNTI (RA-RNTI) may be masked to the CRC.

7 shows an example of an uplink subframe structure.

In FIG. 7, an uplink subframe may be divided into a control region and a data region in the frequency domain. A physical uplink control channel (PUCCH) for carrying uplink control information is allocated to the control region. In the data area, a physical uplink shared channel (PUSCH) for carrying user data is allocated. In order to maintain a single carrier characteristic, one UE does not simultaneously transmit a PUCCH and a PUSCH. PUCCH for one UE is allocated to an RB pair in a subframe. RBs belonging to an RB pair occupy different subcarriers in each of two slots. This is called that the RB pair assigned to the PUCCH is frequency-hopped at the slot boundary.

Hereinafter, the LTE frame structure will be described in more detail.

Through the LTE specification, unless otherwise stated throughout, the size of the various fields in the time domain

Expressed as the number of time units in seconds.

Downlink and uplink transmissions

It is organized into radio frames with a duration of. Two radio frame structures are supported.

Type 1: applicable to FDD

Type 2, applicable to TDD

Frame structure type 1

Frame structure type 1 is applicable to both full duplex and half duplex FDD. Each wireless frame

Length,

It consists of 20 slots, numbered from 0 to 19. A subframe is defined by two consecutive slots, and subframe i consists of slots 2i and 2i + 1.

In the case of FDD, 10 subframes are available for downlink transmission, and 10 subframes are available for uplink transmission every 10 ms.

Uplink and downlink transmissions are separated in the frequency domain. In half-duplex FDD operation, the UE cannot transmit and receive at the same time while there is no such restriction in full-duplex FDD.

8 shows an example of frame structure type 1. FIG.

Frame structure type 2

Frame structure type 2 is applicable to FDD. Length

The length of each radio frame is

Consists of two half-frames. Each half-frame is long

It consists of five subframes. Supported uplink-downlink configurations are listed in Table 2, where for each subframe in a radio frame, "D" indicates that the subframe is reserved for downlink transmission, and "U" indicates sub A frame is reserved for uplink transmission and "S" indicates downlink pilot time slot (DwPTS), guard period (GP) and uplink pilot time slot (UpPTS). Represents a special subframe having three fields of. Total length

The lengths of DwPTS and UpPTS under the same DwPTS, GP and UpPTS premises are given by Table 1. Each subframe i has a length in each subframe

Are defined as two slots, 2i and 2i + 1.

An uplink-downlink configuration with switch-point periodicity from downlink to uplink of both 5 ms and 10 ms is supported. In case of 5 ms downlink to uplink switching point periodicity, the special subframe exists in both half-frames. In the case of periodicity of the switch point periodicity from 10 ms downlink to uplink, the special subframe exists only in the first half frame. Subframes 0 and 5 and DwPTS are always reserved for downlink transmission. Subframes immediately following the UpPTS and the special subframe are always reserved for uplink transmission.

9 illustrates another example of the frame structure type 2. FIG.

Table 1 shows an example of the configuration of the special subframe.

Table 2 shows an example of an uplink-downlink configuration.

<NB-IoT><NB-IoT>

NB-IoT (narrowband-internet of things) is a standard for supporting low complexity and low cost devices, and is defined to perform only relatively simple operations compared to existing LTE devices. NB-IoT follows the basic structure of LTE but operates based on the contents defined below. If the NB-IoT reuses the channel or signal of the LTE, it can follow the standard defined in the existing LTE.

Uplink

The following narrowband physical channels are defined.

Narrowband Physical Uplink Shared Channel (NPUSCH)

Narrowband Physical Random Access Channel (NPRACH)

The following uplink narrowband physical signal is defined.

Narrowband demodulation reference signal

Subcarrier

In terms of uplink bandwidth, and slot duration T _slot are given in Table 3 below.

Table 3 shows an example of NB-IoT parameters.

Single antenna port p = 0 is used for all uplink transmissions.

Resource unit

Resource units are used to describe the mapping of NPUSCHs to resource elements. Resource units are in the time domain

Is defined as successive symbols of, in the frequency domain

Are defined as successive subcarriers of

And

Is given in Table 4.

Table 4

,

And

An example of the supported combinations of

Narrowband uplink shared channel (NPUSCH: Narrowband uplink shared channel)

Narrowband physical uplink shared channels are supported in two formats:

NPUSCH format 1 used to carry the UL-SCH

NPUSCH format 2 used to carry uplink control information

Scrambling is performed in accordance with Section 5.3.1 of TS36.211. The scrambling sequence generator

Is initialized to where n _s is the first slot of the codeword transmission. For NPUSCH repetition, the scrambling sequence is used for n _s and n _f set to the first slot and frame, respectively, used for repetitive transmission.

After the codeword is transmitted, it is reinitialized according to the above equation. quantity

Is provided by clause 10.1.3.6 of TS36.211.

Table 5 specifies the modulation mappings applicable for the narrowband physical uplink shared channel.

The NPUSCH may be mapped to one or more resource units N _RUs , as provided by the section of 3GPP TS 36.213, each of which may be

Is sent once.

Block of complex-valued symbols, in order to comply with the transmit power P _NPUSCH specified in 3GPP TS _36.213

This size scaling factor

It is multiplied by and mapped to subcarriers allocated for transmission of the NPUSCH in a sequence starting with z (0). The mapping to the resource element (k, l) corresponding to subcarriers allocated for transmission and not used for transmission of reference signals is in increasing order of index k and then index l starting from the first slot of the allocated resource unit. .

After N _slots slot mapping,

Before continuing with the mapping to the slot below, slots N _slots

It is repeated an additional number of times, where Equation 1 is

If the mapping to or repetition of the mapping to N _slots slots includes a resource element that overlaps with any configured NPRACH resource according to NPRACH-ConfigSIB-NB, then NPUSCH transmission of nested N _slots slots may result in the next N _slots slots of any configured NPRACH. Defer until no overlap with the resource.

) Mapping

It is repeated until slots are transmitted.

NPUSCH transmissions are postponed after transmissions and / or postponements by NPRACH in time units

Time gaps are inserted. The delay portion due to the NPRACH that matches the gap is counted as part of the gap.

If the upper layer parameter npusch-AllSymbols is set to false, the resource elements of SC-FDMA symbols that overlap with symbols composed of SRS according to srs-SubframeConfig are calculated with NPUSCH mapping but are not used for transmission of NPUSCH. . If the upper layer parameter npusch-AllSymbols is set to true, all symbols are sent.

Uplink control information on NPUSCH without UL-SCH data

HARQ-ACK

1 bit information of is encoded according to Table 6, where, for a positive response

For negative responses

to be.

Table 6 shows an example of HARQ-ACK code words.

Power control

UE transmit power for NPUSCH transmission in the NB-IoT UL slot i for the serving cell is given by

Equations

2 and 3 below.

If the number of repetitions of allocated NPUSCH RUs is greater than two,

Otherwise,

here,

Is the configured UE transmit power defined in 3GPP TS36.101 in NB-IoT UL slot i for serving cell c.

Is {1/4} for the 3.75 kHz subcarrier spacing and {1,3,6,12} for the 15 kHz subcarrier spacing.

Is a component provided from upper layers for serving cell c

Component provided by higher layers for and j = 1

Is the sum of the components, where

to be. J = 1 for NPUSCH (re) transmissions corresponding to a dynamically scheduled grant and j = 2 for NPUSCH (re) transmissions corresponding to a random access response grant.

And

Where the parameter preambleInitialReceivedTargetPower

And

Is signaled from higher layers for serving cell c.

for j = 1, for NPUSCH format 2,

; For NPUSCH format 1

Is provided by higher layers for serving cell c. for j = 2,

to be.

Downlink path loss estimate calculated in dB at the UE for PL _C serving cell c, PL _C = nrs-Power + nrs-PowerOffsetNonAnchor-upper layer filtered NRSRP, where nrs-Power is the higher layer and lower of 3GPP 36.213 Provided by clause 16.2.2, nrs-powerOffsetNonAnchor is set to zero if not provided by higher layers, the NRSRP is defined in 3GPP TS 36.214 for serving cell c, and the higher layer filter configuration for serving cell c Defined in 3GPP TS 36.331.

If the UE transmits NPUSCH in NB-IoT UL slot i for serving cell c, power headroom is calculated using Equation 4 below

UE procedure for transmitting format 1 NPUSCH

Upon detection at a given serving cell of NPDCCH with DCI format N0 ending in NB-IoT DL subframe n for the UE, the UE, at the end of n + k ₀ DL subframe, according to the NPDCCH information

In N consecutive NB-IoT UL slots n _i , performing corresponding NPUSCH transmission using NPUSCH format 1, wherein

Subframe n is the last subframe in which the NPDCCH is transmitted, determined from the start subframe of the NPDCCH transmission and the DCI subframe repetition number field of the corresponding DCI, and

Wherein the value of N _Rep is determined by the repetition number field of the corresponding DCI, and the value of N _RU is determined by the resource allocation field of the corresponding DCI,

Is a number of NB-IoT UL slots of a resource unit corresponding to the number of subcarriers allocated in the corresponding DCI.

n ₀ is the first NB-IoT UL slot starting after the end of subframe n + k ₀ .

The value of k ₀ is determined by a scheduling delay field ( l _Delay ) of the corresponding DCI according to Table 7.

Table 7 shows an example of k0 for DCI format N0.

Resource allocation information of the uplink DCI format N0 for NPUSCH transmission is indicated to the scheduled UE.

A set of consecutively allocated subcarriers n _sc of the resource unit determined by the subcarrier indication field of the corresponding DCI

Multiple resource units (N _RU ) determined by the resource allocation field of the corresponding DCI according to Table 9

The number of repetitions (N _Rep ) determined by the repetition number field of the corresponding DCI according to Table 10.

The subcarrier spacing Δf of the NPUSCH transmission is determined by an uplink subcarrier spacing field of a narrowband random access response grant according to subclause 16.3.3 of 3GPP TS36.213.

For NPUSCH transmission with subcarrier spacing Δf = 3.75 kHz, n _sc = l _sc , where l _sc is the subcarrier indication field of DCI.

For NPUSCH transmission with subcarrier spacing Δf = 15 kHz, the subcarrier indication field l _sc of DCI) determines the set of continuously allocated subcarriers n _sc according to Table 8.

Table 8

An example of subcarriers allocated for an NPUSCH with

Table 9 shows an example of the number of resource units for the NPUSCH.

Table 10 shows an example of the number of repetitions for the NPUSCH.

Demodulation reference signal (DMRS)

Reference signal sequence for

Is defined by Equation 5 below.

Here, the binary sequence c (n) is defined by 7.2 of TS36.211 and must be initialized to c _init = 35 at the start of NPUSCH transmission. The value w (n) is provided by Table 1-11, where group hopping is not enabled for NPUSCH format 1 and for NPUSCH format 2

If group hopping is enabled for NPUSCH format 1, it is provided by 10.1.4.1.3 of 3GPP TS36.211.

Table 11 shows an example of w (n).

The reference signal sequence for NPUSCH format 1 is provided by Equation 6 below.

The reference signal sequence for NPUSCH format 2 is provided by Equation 7 below.

here,

Is

with

Is defined in Table 5.5.2.2.1-2 of 3GPP TS36.211 with the selected sequence index.

Reference Signal Sequences for

Is defined by the cyclic shift α of the base sequence according to Equation 8 below.

here,

Is

Is provided by Table 10.1.4.1.2-1 for

Provided by Table 12 for

Is provided by Table 13.

If group hopping is not enabled, the base sequence index u is

,

, And

For each is provided by higher layer parameters threeTone-BaseSequence, sixTone-BaseSequence, and twelveTone-BaseSequence. If not signaled by higher layers, the base sequence is provided by Equation 9 below.

If group hopping is enabled, the base index u is provided by section 10.1.4.1.3 of 3GPP TS36.211.

And

The cyclic shift for is derived from the upper layer parameters threeTone-CyclicShift and sixTone-CyclicShift, respectively, as defined in Table 14.

For α, α = 0.

Table 12 shows

For

The table which shows an example of the following.

Table 13

For

Table showing another example of the.

Table 14 is a table which shows an example of (alpha).

For the reference signal for NPUSCH format 1, sequence-group hopping may be enabled, where the sequence-group number u of slot n _s is the group hopping pattern f _gh (n _s ) and sequence- according to Equation 10 below. Defined by the transition pattern f _ss .

Where the number of reference signal sequences available for each resource unit size,

Is provided by Table 15.

Table 15

An example is shown.

Sequence-group hopping is enabled or disabled by cell-specific parameters groupHoppingEnabled provided by higher layers. Sequence group hopping for NPUSCH is higher, even though NPUSCH transmission is enabled on a cell basis unless the NPUSCH transmission corresponds to retransmission or random access response acknowledgment of the same transport block as part of a contention based random access procedure. It may be disabled for a particular UE through the layer parameter groupHoppingDisabled.

Group hopping pattern

Is given by Equation 11 below.

here,

About

ego,

Is the slot number of the first slot of the resource unit for. The pseudo-random sequence c (i) is defined by section 7.2. A pseudo-random sequence generator is

At the beginning of the resource unit for and

In every even slot for

Is initialized to

The sequence-transition pattern f _ss is given by Equation 12 below.

here,

Is provided by the higher-layer parameter groupAssignmentNPUSCH. If no value is signaled,

to be.

sequence

Is the size scaling factor

It must be multiplied by and mapped to sub-carriers in a sequence starting with r (0).

The set of sub-carriers used in the mapping process shall be identical to the corresponding NPUSCH transmissions defined in section 10.1.3.6 of 3GPP 36.211.

The mapping to resource elements ( k , l ) should be in increasing order of the first k , then l , and finally the slot number. The values of symbol index l in the slot are provided in Table 16.

Table 16 shows an example of demodulation reference signal positions for NPUSCH.

SF-FDMA Baseband Signal Generation

For, the time-continuous signal of the SC-FDMA symbol l in the slot

end

The value replaced by

As defined by Section 5.6.

For, the time-continuous signal for sub-carrier index k of SC-FDMA symbol l in uplink slot

Is defined by equation (13).

[Revision 28.11.2019 under Rule 91]

[Revision 28.11.2019 under Rule 91]

, Where

And

The parameters for are provided in Table 17,

Is the modulation value of symbol l , and the phase rotation

Is defined by Equation 14 below.

[Revision 28.11.2019 under Rule 91]

here,

Is a symbol counter that is reset at the beginning of transmission and incremented for each symbol during transmission.

Table 17 shows

An example of SC-FDMA parameters for is shown.

SC-FDMA symbols in a slot must be sent in increasing order of l starting with l = 0, where SC-FDMA symbol l > 0 is the time in the slot

Start at

For, the remaining 2304 T _s in the T _slot are not transmitted and are used for the guard period.

Narrowband physical random access channel (NPRACH)

The physical layer random access preamble is based on a single-carrier frequency-hopping symbol group. The symbol group is shown in FIG. 1-8 random access symbol group and consists of a cyclic prefix of length T _CP and a _sequence of five identical symbols of total length T _SEQ . The parameter values are listed in Table 18. Parameter values are listed in Table 18 Random Access Preamble Parameters.

10 shows an example of a random access symbol group.

Table 18 shows an example of random access preamble parameters.

A preamble consisting of four symbol groups transmitted without gaps

Is sent once.

When triggered by the MAC layer, the transmission of the random access preamble is limited to specific time and frequency domains.

The NPRACH configuration provided by higher layers includes the following.

NPRACH Resource Cycle

(nprach-Periodicity),

Frequency location of the first subcarrier assigned to the NPRACH

(nprach-SubcarrierOffset),

Number of subcarriers allocated to NPRACH

(nprach-NumSubcarriers),

Number of starting subcarriers allocated for contention based NPRACH random access

(nprach-NumCBRA-StartSubcarriers),

NPRACH Iterations Per Attempt

(nprach-StartTime),

NPRACH start time

(nprach-StartTime),

Fraction to calculate starting subcarrier index for NPRACH subcarrier range reserved for indication of UE support for multi-tone msg3 transmission

(nprach-SubcarrierMSG3-RangeStart).

NPRACH transmission

Just after the start of the radio frame to meet

The time unit can be started.

After the transmission of time units,

The gap of the time unit is inserted.

NPRACH configurations are not valid.

NPRACH starting subcarriers assigned to contention based random access are divided into two sets of subcarriers,

And

And if present, the second set indicates UE support for multi-tone msg3 transmission.

The frequency position of the NPRACH transmission is

Are constrained within the sub-carrier. Frequency hopping is used within 12 subcarriers, where the frequency position of the i ^th symbol group is

Provided by, where

Equation 15 is

here,

Having

Is

Subcarrier selected by the MAC layer, and the pseudo random sequence c (n) is provided by section 7.2 of GPP TS36.211. Pseudo Random Sequence Generator

Is initialized to

The time-continuous random access signal _sl (t) for symbol group i is defined by Equation 16 below.

here,

ego.

Is the transmit power specified in 16.3.1 of 3GPP TS 36.213.

Is the size scaling factor for

,

Describes the difference in subcarrier spacing between a random access preamble and uplink data transmission, and

The location of the frequency domain controlled by is derived from section 10.1.6.1 of 3GPP TS36.211. variable

Is provided by Table 19.

Table 19 shows an example of random access baseband parameters.

Downlink

The downlink narrowband physical channel corresponds to a set of resource elements carrying information originating from higher layers and is an interface defined between 3GPP TS 36.212 and 3GPP TS 36.211.

The following downlink physical channels are defined

Narrowband Physical Downlink Shared Channel, Narrowband Physical Downlink Shared Channel (NPDSCH)

Narrowband Physical Broadcast Channel, NPBCH (Narrowband Physical Broadcast Channel)

Narrowband Physical Downlink Control Channel, Narrowband Physical Downlink Control Channel (NPDCCH)

The downlink narrowband physical signal corresponds to the set of resource elements used by the physical layer but does not carry information originating from higher layers. The following downlink physical signals are defined:

Narrowband reference signal, narrowband reference signal (NRS)

Narrowband synchronization signal

Narrowband physical downlink shared channel (NPDSCH)

The scrambling sequence generator

Is initialized to, where n _s is the first slot of the codeword transmission. For NPDSCH carrying NPDSCH repetitions and BCCH, the scrambling sequence generator is re-initialized according to the representation described above for each iteration. For NPDSCH repetitions, if the NPDSCH does not carry a BCCH, the scrambling sequence generator uses every _{s of the} codeword with n _s and n _f set to the first slot and frame, respectively, used for repetitive transmission.

After transmission, it is reinitialized according to the above-described representation.

Modulation is performed using the QPSK modulation scheme.

NPDSCH may be mapped to one or more subframes, N _SF , as provided by section 16.4.1.5 of 3GPP TS 36.213, each of which is an NPDSCH

Must be sent once.

For each antenna port used for transmission of the physical channel, a block of complex-valued symbols

Must be mapped to resource elements (k, l) that satisfy all of the following criteria in the current subframe.

Subframes are not used for transmission of NPBCH, NPSS or NSSS, and they are assumed by the UE not to be used for NRS, and

They do not overlap the resource elements used for the CRS (if any), and

The index l of the first slot in the subframe is l

, Where

Is provided by section 16.4.1.4 of 3GPP TS 36.213.

In a sequence starting with

The mapping to resource elements (k, l) through antenna port p that satisfies the above criterion is in increasing order of first index k and index l, starting from the first slot of the subframe and ending with the second slot. For NPDSCH not carrying BCCH, after mapping to subframe,

Before continuing to mapping to the next subframe of,

The subframe is repeated for the additional subframes. after,

Until subframes are transmitted

The mapping of is repeated. For NPDSCH carrying BCCH,

Is mapped in sequence to N _SF subframes, and then

It is repeated until subframes are transmitted.

NPDSCH transmission may be configured by higher layers with transmission gaps in which NPSDCH transmission is deferred.

If there is no gap in the NPDSCH transmission, where

Is provided by the upper layer parameter dl-GapThreshold, and R _max is provided by 3GPP TS 36.213. The gap start frame and subframe

Provided by Gap periodicity,

Is provided by the upper layer parameter dl-GapPeriodicity. The gap duration of a plurality of subframes is

Provided by, where

Is provided by the upper layer parameter dl-GapDurationCoeff. For NPDSCH carrying BCCH, there are no transmission gaps.

If it is not an NB-IoT downlink subframe, except for transmission of the NPDSCH carrying the SystemInformationBlockType1-NB in subframe 4, the UE does not expect the NPDSCH in subframe i. For NPDSCH transmissions, in subframes other than NB-IoT downlink subframes, NPDSCH transmission is delayed until the next NB-IoT downlink subframe.

UE procedure for receiving the NPDSCH

The NB-IoT UE should assume a subframe as an NB-IoT DL subframe in the following case.

The UE determines that the subframe does not include NPSS / NSSS / NPBCH / NB-SIB1 transmission, and

For NB-IoT carriers where the UE receives higher layer parameter operationModeInfo, the subframe consists of NB-IoT DL subframes after the UE acquires SystemInformationBlockType1-NB.

-In case of NB-IoT carrier in which DL-CarrierConfigCommon-NB exists, a subframe is composed of NB-IoT DL subframes by an upper layer parameter downlinkBitmapNonAnchor.

In case of an NB-IoT UE supporting twoHARQ-Processes-r14, there must be a maximum of two downlink HARQ processes.

Upon detection for a given serving cell of NPDCCH with DCI formats N1, N2 ending in subframe n intended for the UE, the UE starts at n + 5 DL subframe and according to NPDCCH information.

Decode corresponding NPDSCH transmissions of N consecutive NB-IoT DL subframe (s) n _i with

Subframe n is the last subframe in which the NPDCCH is transmitted, and is determined from the start subframe of the NPDCCH transmission and the DCI subframe repetition number field of the corresponding DCI;

subframe (s) ni with i = 0,1, ..., N-1 are N consecutive NB-IoT DL subframe (s) excluding subframes used for SI messages, where n0 <n1 <..., nN-1,

Wherein the value of N _Rep is determined by the repetition number field of the corresponding DCI, the value of N _SF is determined by the resource allocation field of the corresponding DCI, and

k ₀ is the number of NB-IoT DL subframe (s) starting from DL subframe n + 5 to DL subframe n ₀ , where k ₀ is determined by a scheduling delay field (I _Delay ) for DCI format N1, K ₀ = 0 for DCI format N2. For DCI CRC scrambled by G-RNTI, k ₀ is determined by the scheduling delay field (I _Delay ) according to Table 21; otherwise k ₀ is determined by the scheduling delay field (I _Delay ) according to Table 20. do. The value of R _{m, ax} is in accordance with subclause 16.6 of 3GPP 36.213 for the corresponding DCI format N1.

Table 20 shows an example of k ₀ for DCI format N1.

Table 21 shows an example of k ₀ for DCI format N1 with DCI CRC scrambled by G-RNTI.

After the end of the NPUSCH transmission by the UE, the UE is not expected to receive transmissions in three DL subframes.

Resource allocation information of DCI formats N1 and N2 (paging) for the NPSICH is indicated to the scheduled UE.

Table 22 shows an example of the number of subframes for the NPDSCH. The number of subframes (N _SF ) determined by the resource allocation field (I _SF ) in the corresponding DCI according to Table 22.

The number of repetitions (N _Rep ) determined by the number of repetitions field (I _Rep ) in the corresponding DCI according to Table 23.

Table 23 shows an example of the number of repetitions for the NPDSCH.

The number of repetitions for the NPDSCH carrying SystemInformationBlockType1-NB is determined based on the parameter schedulingInfoSIB1 configured by higher-layers, and is in accordance with Table 24.

Table 24 shows an example of the number of repetitions for SIB1-NB.

The starting radio frame for the first transmission of the NPDSCH carrying SystemInformationBlockType1-NB is determined according to Table 125.

Table 25 shows an example of a starting radio frame for the first transmission of the NPDSCH carrying SIB1-NB.

Start OFDM symbol for NPDSCH is the index of the first slot of subframe k.

Provided by, and determined as follows:

If subframe k is a subframe used to receive SIB1-NB,

If the value of the upper layer parameter operationModeInfo is set to '00' or '01'

Otherwise

-Otherwise,

If the value of the upper layer parameter eutraControlRegionSize exists

Is provided by the upper layer parameter eutraControlRegionSize

Otherwise

UE procedure for reporting ACK / NACK

Upon detection of an NPDSCH transmission intended for the UE and ending in the NB-IoT subframe n for which ACK / NACK should be provided, the UE is responsible for using NPUSCH format 2 in N consecutive NB-IoT UL slots. Of the NPUSCH carrying the response

At the end of the DL subframe transmission, it should be provided and started, where

ego,

The value of is provided by the upper layer parameter ack-NACK-NumRepetitions-Msg4 and the higher layer parameter ack-NACK-NumRepetitions configured for the associated NPRACH resource for Msg4 NPDSCH transmission,

Is the number of slots in the resource unit,

The subcarriers allocated for ACK / NACK and the value of k0 are determined by the ACK / NACK resource field of the DCI format of the corresponding NPDCCH according to Table 16.4.2-1 and Table 16.4.2-2 of 3GPP TS36.213. .

Narrowband physical broadcast channel (NPBCH)

The processing structure for the BCH transport channel is according to 5.3.1 of 3GPP TS 36.212, and has the following differences.

The transmission time interval (TTI) is 640 ms.

The size of the BCH transport block is set to 34 bits.

The CRC mask for NPBCH is selected according to one or two transmit antenna ports in the eNodeB according to Table 5.3.1.1-1 of 3GPP TS 36.212, where the transmit antenna ports are defined in section 10.2.6 of 3GPP TS 36.211. have.

The number of rate matching bits is defined in section 10.2.4.1 of 3GPP TS 36.211.

Scrambling is performed according to section 6.6.1 of 3GPP TS 36.211 using M _bits indicating the number of bits to be transmitted on the NPBCH. M _bit is equal to 1600 for a normal cyclic prefix. The scrambling sequence

In wireless frames satisfying

Is initialized to

Modulation is performed using the QPSK modulation scheme for each antenna port,

Is transmitted in subframe 0 for 64 consecutive radio frames starting from each radio frame that satisfies.

Layer mapping and precoding are performed according to section 6.6.3 of 3GPP TS 36.211, which is P∈ {1,2}. The UE assumes that antenna ports R ₂₀₀₀ and R ₂₀₀₁ are used for transmission of the narrowband physical broadcast channel.

Block of complex-valued symbols for each antenna port

silver

Resource not transmitted for transmission of reference signals starting with consecutive radio frames starting with y (0) and transmitted in subframe 0 for 64 consecutive radio frames starting at each radio frame satisfying It must be mapped to a sequence of elements (k, l), followed by the first index k, followed by the increment of index l. After mapping to subframe, in subsequent radio frames

Before continuing to subframe 0 of the subframe, the subframe is repeated to subframe 0 in the next seven radio frames. The first three OFDM symbols of the subframe are not used in the mapping process. For mapping purposes, the UE assumes narrowband reference signals for antenna ports 2000 and 2001 and cell-specific reference signals for antenna ports 0-3 that are present regardless of the actual configuration. The frequency shift of cell-specific reference signals is determined by the cell in the calculation of V _shift in section 6.10.1.2 of 3GPP TS 36.211.

of

Replace with.

Narrowband physical downlink control channel (NPDCCH)

The narrowband physical downlink control channel carries control information. The narrowband physical control channel is transmitted through the aggregation of one or two consecutive narrowband control channel elements (NCCEs), where the narrowband control channel elements are six consecutive in a subframe. Corresponding to subcarriers, where NCCE 0 occupies subcarriers 0-5 and NCCE 1 occupies subcarriers 6-11. NPDCCH supports several formats listed in Table 1-26. In the case of NPDCCH format 1, all NCCEs belong to the same subframe. One or two NPDCCHs may be transmitted in a subframe.

Table 26 shows an example of supported NPDCCH formats.

Scrambling shall be performed in accordance with Section 6.8.2 of TS36.211. The scrambling sequence

After every fourth NPDCCH subframe with N shall be initialized at the beginning of subframe k ₀ according to clause 16.6 of TS36.213, where scrambling is the first slot of the NPDCCH subframe (re-) initialized.

Modulation is performed using the QPSK modulation scheme in accordance with section 6.8.3 of TS36.211.

Layer mapping and precoding are performed according to section 6.6.3 of TS36.211 using the same antenna port as the NPBCH.

Block of complex-valued symbols

Is mapped to resource elements (k, l) in a sequence starting with y (0) through an associated antenna port that meets all of the following criteria:

These are part of the NCCE (s) allocated for NPDCCH transmission, and

These are assumed not to be used for transmission of NPBCH, NPSS, or NSSS, and

These are assumed not to be used by the UE for NRS, and

They do not overlap (if any) the resource elements used for PBCH, PSS, SSS, or CRS as defined in clause 6 of TS36.211, and

The index l of the first slot of the subframe is

Satisfying where

Is provided by section 16.6.1 of 3GPP TS 36.213.

The mapping to the resource elements (k, l) through the antenna port p satisfying the above criteria is the order of index k first, then index l, starting from the first slot of the subframe and ending with the second slot.

NPDCCH transmission may be configured by higher layers having transmission gaps in which NPDCCH transmission is delayed. The configuration is the same as that described for the NPDSCH in Section 10.2.3.4 of TS36.211.

If it is not an NB-IoT downlink subframe, the UE does not expect the NPDCCH in subframe i. For NPDCCH transmissions, in subframes other than NB-IoT downlink subframes, NPDCCH transmissions are deferred until the next NB-IoT downlink subframe.

DCI format

DCI format N0

DCI format N0 is used for scheduling of NPUSCH in one UL cell. The following information is transmitted by DCI format N0.

Format N0 / Format N1 Classification (1 bit), subcarrier indication (6 bits), resource allocation (3 bits), scheduling delay (2 bits), modulation and coding scheme (4 bits), redundancy version (1 bit), number of repetitions (3 bits), new data indicator (1 bit), flag for DCI subframe repeat count (2 bits)

DCI format N1

DCI format N1 is used for the random access procedure initiated by scheduling and NPDCCH order of one NPDSCH codeword in one cell. The DCI corresponding to the NPDCCH order is carried by the NPDCCH. The following information is transmitted by DCI format N1:

Format N0 / format N1 distinction (1 bit), flag for NPDCCH order indicator (1 bit)

The format N1 is used for the random access procedure initiated by the NPDCCH order only when the NPDCCH order indicator is set to "1", the format N1 CRC is scrambled to C-RNTI, and all remaining fields are set as follows:

Start number of NPRACH repetitions (2 bits), subcarrier indication (6 bits) of NPRACH, all remaining bits of format N1 are set to 1

Otherwise,

-Scheduling delay (3 bits), resource allocation (3 bits), modulation and coding scheme (4 bits), number of repetitions (4 bits), new data indicator (1 bit), HARQ-ACK resource (4 bits), DCI sub Frame repeat count (2 bits)

If the format N1 CRC is scrambled to RA-RNTI, the next field of the above fields is reserved.

New data indicator, HARQ-ACK resource

If the number of information bits of the format N1 is smaller than the number of information bits of the format N0, zero is appended to the format N1 until the payload size becomes equal to the format N0.

DCI format N2

DCI format N2 is used for paging and direct indication. The following information is transmitted by DCI format N2.

Flag to distinguish paging / direct indication (1 bit)

If flag = 0:

Direct indication information (8 bits), reserved information bits are added until the size is the same size as the size of format N2 with flag = 1

If flag = 1:

Resource allocation (3 bits), modulation and coding scheme (4 bits), number of repetitions (4 bits), number of DCI subframe repetitions (3 bits)

NPDCCH related procedures

The UE should monitor the NPDCCH candidate set configured by higher layer signaling for control information, where monitoring means attempting to decode each NPDCCH in the set according to all monitored DCI formats.

Aggregation level

And repeat level

NPDCCH search space in

Is defined by a set of NPFCCH candidates, where each candidate is repeated with a set of R consecutive NB-IoT downlink subframes except subframes used for transmission of SI messages starting with subframe k.

Position of the starting subframe k is provided by a k = k _b, where a k = k _b is NB-IoT DL subframes excluding subframes used for transmission of the SI message, and b the second consecutive sub-frames k0,

, ego

And subframe k0 is a condition

Is a subframe satisfying

,

to be. G and

Is provided by a higher layer parameter.

For type 1-NPDCCH common search space, k = k0 and is determined from the locations of NB-IoT paging opportunity subframes.

If the UE is configured by a higher layer with an NB-IoT carrier to monitor the NPDCCH UE-specific search space,

The UE monitors the NPDCCH UE-specific discovery space through a higher layer configured NB-IoT carrier,

The UE is not expected to receive NPSS, NSSS, NPBCH on the higher layer configured NB-IoT carrier.

Otherwise,

The UE monitors the NPDCCH UE-specific search space through the same NB-IoT carrier from which NPSS / NSSS / NPBCH is detected.

Index in first slot of subframe k

The starting OFDM symbol for the NPDCCH provided by is determined as follows:

The upper layer parameter eutraControlRegionSize exists

Is provided by the upper layer parameter eutraControlRegionSize.

Otherwise,

Narrowband reference signal (NRS)

Before the UE obtains operationModeInfo, the UE may assume that narrowband reference signals are transmitted in subframe # 9 and in subframes # 0 and # 4 that do not include NSSS.

When the UE receives the upper layer parameter operationModeInfo indicating guardband or standalone,

Before the UE acquires SystemInformationBlockType1-NB, the UE may assume that narrowband reference signals are transmitted in subframe # 9 that does not include NSSS and in subframes # 0, # 1, # 3, # 4.

After the UE acquires SystemInformationBlockType1-NB, the UE receives narrowband reference signals in subframes # 9, subframes # 0, # 1, # 3, and # 4 that do not include NSSS and in NB-IoT downlink subframes. It can be assumed to be transmitted and does not expect narrowband reference signals in other downlink subframes.

If the UE receives the higher layer parameter operationModeInfo indicating in-band-SamePCI or in-band-DifferentPCI,

Before the UE acquires the SystemInformationBlockType1-NB, the UE may assume that narrowband reference signals are transmitted in subframe # 9 that does not include NSSS and in subframes # 0 and # 4.

After the UE acquires SystemInformationBlockType1-NB, it is assumed that the narrowband reference signals are transmitted in subframe # 9, subframes # 0, # 4 and in the NB-IoT downlink subframe, which do not include NSSS. And do not expect narrowband reference signals in other downlink subframes.

Narrowband primary synchronization signal (NPSS)

The sequence d _l (n) used for the narrowband primary synchronization signal is generated from the Zadoff-Chu sequence in the frequency domain according to Equation 17 below.

Here, Zadoff-Chu root sequence index u = 5 and S (l) for different symbol indices l are provided in Table 27.

Table 27 shows an example of S (l).

The same antenna port should be used for all symbols of the narrowband primary sync signal in the subframe.

The UE should not assume that the narrowband primary sync signal is transmitted through the same antenna port as any downlink reference signal. The UE should not assume that transmissions of the narrowband primary sync signal in a given subframe use the same antenna port or ports, such as the narrowband primary sync signal in any other subframe.

The sequences d _l (n) are the first index in subframe 5 within every radio frame.

And subsequent indexes

Should be mapped to resource elements (k, l) in increasing order of. For resource elements (k, l) that overlap with the resource elements over which cell specific reference signals are transmitted, the corresponding sequence element d (n) is not used for NPSS but is counted in the mapping process.

Narrowband secondary synchronization signals (NSSS)

The sequence d (n) used for the narrowband secondary synchronization signal is generated from the frequency domain Zadoff-Chu sequence according to Equation 18 below.

here,

The binary sequence b _q (n) is provided by Table 28. Circular transition of frame number n _f

Is

Provided by

Table 28 shows an example of b _q (n).

The same antenna port should be used for all symbols of the narrowband secondary sync signal in the subframe.

The UE should not assume that the narrowband secondary synchronization signal is transmitted through the same antenna port as any downlink reference signal. The UE shall not assume that transmissions of the narrowband secondary synchronization signal in a given subframe use the same antenna port, or ports as the narrowband secondary synchronization signal of any other subframe.

The sequence d (n) is the last allocated in radio frames satisfying the first index k and then n _f mod 2 = 0 on 12 assigned subcarriers.

Symbols must be mapped to resource elements (k, l) in a sequence starting with d (0) in increasing order of index l, where

Is provided in Table 29.

Table 29 shows an example of the number of NSSS symbols.

OFDM baseband signal generation

If the upper layer parameter operationModeInfo does not indicate 'in-band-SamePCI' and samePCI-Indicator does not indicate 'samePCI', the time-continuous signal through the antenna port p of the OFDM symbol l in the downlink slot

Is defined by Equation 19 below.

, Where

, N = 2048,

ego,

Is the content of the resource element (k, l) through the antenna port.

If the higher layer parameter operationModeInfo indicates' in-band-SamePCI 'or samePCI-Indicator indicates'samePCI', time-continuous signal through antenna port p of OFDM symbol l '

Where

Is an OFDM symbol index at the start of the last even subframe and is defined by Equation 20 below.

, Where

And

If the resource element (k, l ') is used for narrowband IoT

, Otherwise 0,

Is the frequency position of the carrier of the narrowband IoT PRB minus the center frequency position of the LTE signal.

In certain 3GPP specs, only normal CP is supported for narrowband IoT downlink.

Hereinafter, the physical layer process of the narrowband physical broadcast channel (NPBCH) will be described in more detail.

Scrambling

In wireless frames satisfying

Is initialized to

Modulation

Modulation is carried out using the modulation schemes in table 10.2.4.2-1 according to clause 6.6.2 of TS36.211.

Table 30 shows an example of a modulation scheme for NPBCH.

Layer mapping and precoding

Mapping to Resource Elements

Block of complex-value symbols for each antenna port

Is transmitted in subframe 0 for 64 consecutive radio frames starting at each radio frame that satisfies n _f mod64 =, and starts transmission of reference signals starting with successive radio frames starting with y (0). Must be mapped to a sequence of unreserved resource elements (k, l), followed by increasing order of index l after the first index k. After mapping to subframe, in subsequent radio frames

Before continuing to subframe 0 of the subframe, the subframe is repeated to subframe 0 in the next seven radio frames. The first three OFDM symbols of the subframe are not used in the mapping process.

For mapping purposes, the UE assumes narrowband reference signals for antenna ports 2000 and 2001 and cell-specific reference signals for antenna ports 0-3 that are present regardless of the actual configuration. The frequency shift of cell-specific reference signals is determined by the cell in the calculation of v _shift in section 6.10.1.2 of 3GPP TS 36.211.

of

Replace with.

Next, the information related to MIB-NB and SIBN1-NB will be described in more detail.

Master Information Block (NB) -NB

The MasterInformationBlock-NB contains system information transmitted over the BCH.

Signaling radio bearer: N / A

RLC-SAP: TM

Logical Channel: BCCH

Direction: E-UTRAN to UE

Table 31 shows an example of the MasterInformationBlock-NB format.

Table 32 shows a description of the MasterInformationBlock-NB field.

System Information Block Type 1-NB

The SystemInformationBlockType1-NB message contains relevant information when evaluating whether a UE is allowed to access a cell and defines the scheduling of other system information.

Signaling radio bearer: N / A

RLC-SAP: TM

Logical Channel: BCCH

Direction: E-UTRAN to UE

Table 33 shows an example of a SystemInformationBlockType1 (SIB1) -NB message.

Table 34 shows a description of the SystemInformationBlockType1-NB field.

Initial Access Procedure of NB-IoT

In the general signal transmission / reception procedure of the NB-IoT, a procedure of initially accessing the NB-IoT terminal to the base station has been briefly described. In detail, the procedure for initial access by the NB-IoT terminal to the base station may include a procedure for searching for an initial cell and a procedure for acquiring system information by the NB-IoT terminal.

In this regard, a detailed signaling procedure between the UE (UE) and the base station (eg, NodeB, eNodeB, eNB, gNB, etc.) related to the initial access of the NB-IoT may be illustrated in FIG. 11. Hereinafter, detailed description of the initial access procedure of the general NB-IoT, configuration of NPSS / NSSS, acquisition of system information (eg, MIB, SIB, etc.) will be described with reference to FIG. 11.

FIG. 11 is an example of an initial access procedure of an NB-IoT, and names of each physical channel and / or physical signal may be set or referred to according to a wireless communication system to which the NB-IoT is applied. For example, although FIG. 11 is basically described in consideration of the NB-IoT based on the LTE system, this is only for convenience of description, and the content thereof may be extended to the NB-IoT based on the NR system. .

FIG. 15 is an example of an initial access procedure of an NB-IoT, and names of each physical channel and / or physical signal may be set or referred to according to a wireless communication system to which the NB-IoT is applied. For example, although FIG. 15 is basically described in consideration of the NB-IoT based on the LTE system, this is for convenience of description only, and the content thereof may be extended to the NB-IoT based on the NR system. .

As shown in FIG. 11, the NB-IoT is based on the following signals transmitted in the downlink: primary and secondary narrowband synchronization signals (NPSS and NSSS). NPSS is transmitted on 11 subcarriers from the first subcarrier to the 11th subcarrier in the 6th subframe of each frame (S110), and NSSS is the first of every even frame for TDD in the 10th subframe for FDD In the first subframe, it is transmitted on 12 subcarriers on the NB-IoT carrier (S120).

The NB-IoT UE may receive a Master Information Block-NB (MIB-NB) on a NB Physical Broadcast Channel (NPBCH) (S130).

The MIB-NB uses a fixed schedule with periods of 640 ms and iterations made within 640 ms. The first transmission of the MIB-NB is scheduled in subframe # 0 of radio frames with SFN mod 64 = 0, and repetitions are all scheduled in subframe # 0 of another radio frame. These transmissions are arranged in eight independently decodable blocks of 80 ms duration.

Thereafter, the NB-IoT UE may receive a SIB1-NB (SystemInformationBlockType1-NB) on the PDSCH (S140).

SIB1-NB uses a fixed schedule with a period of 2560 ms. SIB1-NB transmission occurs in subframe # 4 of all other frames in 16 consecutive frames. The start frame for the first transmission of SIB1-NB is derived by the cell PCID and the number of iterations in the 2560 ms period. Iterations are made at equal intervals within a 2560 ms period. The repetition made within TBS and 2560ms for SystemInformationBlockType1-NB is indicated by the scheduleInfoSIB1 field of the MIB-NB.

The SI message is transmitted in time domain windows (referred to as SI-windows) that occur periodically using the scheduling information provided in SystemInformationBlockType1-NB. Each SI message is associated with an SI window, and the SI windows of other SI messages do not overlap. That is, only SI corresponding to one SI window is transmitted. If set, the length of the SI window is common to all SI messages.

Within the SI window, the corresponding SI message may be sent multiple times on two or eight consecutive NB-IoT downlink subframes according to the TBS. The UE uses detailed time / frequency domain scheduling information and other information. The other information may be, for example, a transmission format for an SI message in a schedulingInfoList field of SystemInformationBlockType1-NB. The UE does not need to accumulate several SI messages in parallel, but may need to accumulate SI messages over multiple SI windows depending on coverage conditions.

SystemInformationBlockType1-NB sets the length and transmission period of the SI window for all SI messages.

In addition, the NB-IoT UE may receive a SystemInformationBlockType2-NB (SIB2-NB) on the PDSCH for additional information (S150).

On the other hand, as shown in Figure 11 NRS means a narrowband reference signal.

Random Access Procedure of NB-IoT

In the general signal transmission and reception procedure of the NB-IoT, a procedure of random access of the NB-IoT terminal to the base station has been briefly described. In detail, a procedure in which the NB-IoT terminal randomly accesses the base station may be performed through a procedure in which the NB-IoT terminal transmits a preamble to the base station and receives a response thereto.

In this regard, a detailed signaling procedure between a UE (eg, a UE and a base station (eg, NodeB, eNodeB, eNB, gNB, etc.) related to random access of the NB-IoT) may be illustrated as shown in FIG. 12. The following describes the random access procedure based on the messages (eg, msg1, msg2, msg3, msg4) used in the general NB-IoT random access procedure.

FIG. 12 is an example of a random access procedure of an NB-IoT, and names of respective physical channels, physical signals, and / or messages may be set or referred to according to a wireless communication system to which the NB-IoT is applied. For example, although FIG. 12 is basically described in consideration of NB-IoT based on an LTE system, this is only for convenience of description, and the content thereof may be extended to NB-IoT based on NR system. .

12 is an example of a random access procedure of the NB-IoT, the name of each physical channel, physical signal, and / or message may be set or referred to differently depending on the wireless communication system to which the NB-IoT is applied. For example, although FIG. 16 is basically described in consideration of NB-IoT based on an LTE system, this is only for convenience of description, and the content thereof may be extended to NB-IoT based on NR system. .

As shown in FIG. 12, for NB-IoT, the RACH procedure has the same message flow as LTE with different parameters.

Hereinafter, the NPRACH transmitted by the NB-IoT terminal to the base station in relation to the random access procedure of the NB-IoT will be described in detail.

13 shows a structure of a random access symbol group.

As shown in FIG. 13, a random access symbol group is composed of a cyclic prefix of length and a sequence of identical symbols having a total length. The total number of symbol groups in the preamble repeating unit is denoted by P. The number of time-continuous symbol groups is given by G.

The parameter values of

frame structures

1 and 2 are shown in Table 36 and Table 37, respectively.

Transmission of the random access preamble is limited to specific time and frequency resources when triggered by the MAC layer. Up to three NPRACH resource configurations may be configured in a cell where each NPRACH resource configuration corresponds to a different coverage level. NPRACH resource configuration is given by periodicity, number of repetitions, start time, frequency location, and subcarrier number.

NB-IoT's Discontinous Reception Procedure

While performing the above-described general signal transmission / reception procedure of the NB-IoT, the NB-IoT terminal is in an idle state (eg, an RRC_IDLE state) and / or an inactive state in order to reduce power consumption. ) (Eg, RRC_INACTIVE state). In this case, the NB-IoT terminal switched to the valid state and / or inactive state may be configured to use the DRX scheme. For example, the NB-IoT terminal switched to the idle state and / or inactive state may monitor the NPDCCH related to paging only in a specific subframe (or frame or slot) according to the DRX cycle set by the base station or the like. It can be set to perform. Here, the NPDCCH related to paging may refer to an NPDCCH scrambled with P-RNTI (Paging Access-RNTI).

As shown in FIG. 14, an NB-IoT UE in an RRC_IDLE state only has some subframes (SF) in relation to paging (ie, paging, if PO) within a subset of radio frames (ie, paging frame, PF). Monitor. Paging is used to trigger an RRC connection and indicate a change in system information for the UE in RRC_IDLE mode.

That is, DRX configuration and indication for the NB-IoT terminal may be performed as shown in FIG. 15. In addition, FIG. 15 is merely for convenience of description and does not limit the method proposed herein.

Referring to FIG. 15, the NB-IoT terminal may receive DRX configuration information from a base station (eg, NodeB, eNodeB, eNB, gNB, etc.) (S210). In this case, the terminal may receive such information from the base station through higher layer signaling (eg, RRC signaling). Here, the DRX configuration information may include DRX cycle information, DRX offset, setting information on timers related to DRX, and the like.

Thereafter, the NB-IoT terminal may receive a DRX command (DRX command) from the base station (S220). In this case, the terminal may receive such a DRX command from the base station through higher layer signaling (eg, MAC-CE signaling).

The NB-IoT terminal receiving the aforementioned DRX command may monitor the NPDCCH in a specific time unit (eg, subframe, slot) according to a DRX cycle (S230). Here, monitoring the NPDCCH, after decoding a specific area of the NPDCCH according to the DCI format (DCI format) to be received through the corresponding search area (scrambling) scrambling the CRC to a predetermined predetermined RNTI value This can mean checking whether it matches (i.e. matches) the desired value.

When the corresponding NMB-IoT terminal receives information indicating a change in its paging ID and / or system information through the procedure as shown in FIG. 15 described above, initializes a connection (eg, RRC connection) with the base station. (Or reset) or receive (or obtain) new system information from the base station.

If the NB-IoT UE detects the NPDCCH using Paging Access Radio Network Temporary Identifier (P-RNTI) in the PO, the NB-IoT UE decodes the corresponding NPDSCH. The paging message is transmitted through the NPDSCH and may include information including a list of NB-IoT UEs to be paged and whether paging is for connection establishment or whether system information has been changed. Each NB-IoT UE finding its ID in this list may receive a command to forward it to the paged upper layer, which in turn initiates an RRC connection. If the system information is changed, the NB-IoT UE may start reading the SIB1-NB and obtain information in the SIB1-NB that should read the SIB again.

16 shows one example of a cycle of DRX.

As shown in FIG. 16, the DRX cycle designates a periodic repetition within the interval that precedes the period of inactivity. The MAC entity may be configured by the RRC with a DRX function that controls the UE's PDCCH monitoring activity for the RNTI of the MAC entity (eg, C-RNTI). Thus, the NB-IoT UE may monitor the PDCCH for a short period (eg, on duration) and stop monitoring the PDCCH for a long period (eg, an opportunity for DRX). If DRX is configured when in RRC_CONNECTED (ie connected mode DRX, CDRX), the MAC entity can discontinuously monitor the PDCCH using the DRX operation specified below. Otherwise, the MAC entity constantly monitors the PDCCH. For NB-IoT, PDCCH may refer to NPDCCH. For NB-IoT, an extended DRX cycle of 10.24 s is supported in RRC Connected.

RRC includes timers for DurationTimer, drx-InactivityTimer, drx-RetransmissionTimer (one HARQ process scheduled using 1ms TTI, one per DL HARQ process except broadcast process), drx-RetransmissionTimerShortTTI (HARQ process scheduled using short TTI) Configure DRX to control DRX operation. 1 per DL HARQ process), drx-ULRetransmissionTimer (for HARQ processes scheduled using 1ms TTI, 1 per asynchronous UL HARQ process), drx-ULRetransmissionTimerShortTTI (for HARQ processes scheduled using short TTI, asynchronous UL HARQ 1 per process), repeating the value of longDRX-drxStartOffset and optionally the values of drxShortCycleTimer and shortDRX-Cycle. HARQ RTT timers per DL HARQ process (except for broadcast processes) and UL HARQ RTT timers per asynchronous UL HARQ process are also defined.

Machine Type Communication (MTC) is an application that does not require much throughput that can be applied to machine-to-machine (M2M) or Internet-of-Things (IoT), and is an IoT service in the 3rd Generation Partnership Project (3GPP). A communication technology adopted to meet the requirements of

MTC can be implemented to meet the criteria of (i) low cost & low complexity, (ii) enhanced coverage, and (iii) low power consumption.

In 3GPP, MTC has been applied since release 10, and the features of MTC added for each release of 3GPP are briefly described.

First, the MTC described in 3GPP release 10 and release 11 relates to a load control method.

The load control method is to prevent IoT (or M2M) devices from suddenly loading the base station.

More specifically, in the case of release 10, the base station relates to a method of controlling the load by disconnecting the connected IoT devices in case of a load, and in the case of release 11, the base station performs a broadcasting such as SIB14. The present invention relates to a method of blocking access to a terminal in advance by notifying the terminal in advance of a later access.

In Release 12, features for low cost MTC were added, and UE category 0 was newly defined. The UE category is an index indicating how much data the terminal can process in the communication modem.

That is, a UE of category 0 uses a half duplex operation having a reduced peak data rate, relaxed RF requirements, and a single receive antenna, thereby reducing baseband and RF complexity of the UE.

In Release 13, a new technology called eMTC (enhanced MTC) was introduced, and it was designed to operate only at 1.08MHz, the minimum frequency bandwidth supported by legacy LTE.

The contents described below are mainly related to features related to eMTC, but may also be applied to MTC to be applied to MTC, eMTC, 5G (or NR) unless otherwise specified. Hereinafter, for convenience of description, the description will be collectively referred to as MTC.

Therefore, MTC to be described later is eMTC (enhanced MTC), LTE-M1 / M2, BL (Bandwidth reduced low complexity) / CE (coverage enhanced), non-BL UE (in enhanced coverage), NR MTC, enhanced BL / CE and the like May be referred to as other terms. That is, the term MTC may be replaced with a term to be defined in a future 3GPP standard.

MTC General Features

(1) MTC operates only on a specific system bandwidth (or channel bandwidth).

The specific system bandwidth may use 6RB of legacy LTE as shown in Table 38 below, and may be defined in consideration of the frequency range and subcarrier spacing of the NR defined in Tables 39 to 41. The specific system bandwidth may be represented by a narrowband (NB). For reference, Legacy LTE means a part described in the 3GPP standard other than MTC. Preferably, the MTC in NR may operate using RBs corresponding to the lowest system bandwidth of Tables 40 and 41 below, as in legacy LTE. Alternatively, in NR, the MTC may operate in at least one bandwidth part (BWP) or in a specific band of BWP.

Table 39 is a table showing a frequency range (FR) defined in NR.

Table 40 shows an example of the maximum transmission bandwidth configuration (NRB) for channel bandwidth and SCS at FR 1 of NR.

Table 41 is a table showing an example of the maximum transmission bandwidth configuration (NRB) for channel bandwidth and SCS in FR 2 of the NR.

The MTC narrowband (NB) will be described in more detail.

MTC follows a narrowband operation to transmit and receive physical channels and signals, and the maximum channel bandwidth is reduced to 1.08 MHz or 6 (LTE) RBs.

The narrowband may be used as a reference unit for resource allocation units of some channels of downlink and uplink, and the physical location of each narrowband in the frequency domain may be defined differently according to system bandwidth.

The bandwidth of 1.08 MHz defined in the MTC is defined so that the MTC terminal follows the same cell search and random access procedure as the legacy terminal.

MTC can be supported by a cell with a bandwidth much larger than 1.08 MHz (eg, 10 MHz), but the physical channels and signals transmitted and received by the MTC are always limited to 1.08 MHz.

The system with much higher bandwidth may be legacy LTE, NR system, 5G system and the like.

Narrowband is defined as six non-overlapping contiguous physical resource blocks in the frequency domain.

if

If, wideband is defined as four non-overlapping narrowbands in the frequency domain. if

If is

And a single wideband

It consists of non-overlapping narrowband (s).

For example, in the case of 10 MHz channels (50 RBs), eight non-overlapping narrowbands are defined.

Referring to FIG. 17B, frequency diversity by RF retuning will be described.

Due to narrowband RF, single antenna and limited mobility, MTC supports limited frequency, space and time diversity. To reduce the effects of fading and outage, frequency hopping is supported between different narrowbands by RF retuning.

This frequency hopping is applied to different uplink and downlink physical channels when repetition is possible.

For example, when 32 subframes are used for PDSCH transmission, the first 16 subframes may be transmitted on the first narrowband. At this time, the RF front-end is retuned to another narrowband, and the remaining 16 subframes are transmitted on the second narrowband.

The narrowband of the MTC may be configured by system information or downlink control information (DCI).

(2) MTC operates in half duplex mode and uses a limited (or reduced) maximum transmit power.

(3) MTC does not use a channel (defined in legacy LTE or NR) that must be distributed over the entire system bandwidth of legacy LTE or NR.

For example, legacy LTE channels not used for MTC are PCFICH, PHICH, PDCCH.

Therefore, the MTC cannot monitor the above channels and defines a new control channel, MPDCCH (MTC PDCCH).

The MPDCCH spans up to 6RBs in the frequency domain and one subframe in the time domain.

MPDCCH is similar to EPDCCH and additionally supports common search space for paging and random access.

The MPDCCH is similar to the concept of E-PDCCH used in legacy LTE.

(4) The MTC uses a newly defined DCI format, and may be, for example, DCI formats 6-0A, 6-0B, 6-1A, 6-1B, 6-2, and the like.

(5) MTC includes a physical broadcast channel (PBCH), a physical random access channel (PRACH), an MTC physical downlink control channel (M-PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), and a physical PUSCH (PUSCH). uplink shared channel) can be transmitted repeatedly. This MTC repetitive transmission can decode the MTC channel even when signal quality or power is very poor, such as in a basement environment, resulting in an increase in cell radius and signal penetration. The MTC may support only a limited number of transmission modes (TM) that can operate in a single layer (or single antenna), or support a channel or reference signal (RS) that can operate in a single layer. . In one example, the transmission mode in which the MTC can operate may be

TM

1, 2, 6, or 9.

(6) HARQ retransmission of MTC is adaptive and asynchronous, and is based on a new scheduling assignment received in MPDCCH.

(7) PDSCH scheduling (DCI) and PDSCH transmission in MTC occur in different subframes (cross subframe scheduling).

(8) All resource allocation information (subframe, transport block size (TBS), subband index) for SIB1 decoding is determined by a parameter of the MIB, and no control channel is used for SIB1 decoding of MTC.

(9) All resource allocation information (subframe, TBS, subband index) for SIB2 decoding is determined by various SIB1 parameters, and no control channel for SIB2 decoding of MTC is used.

(10) MTC supports extended paging (DRX) cycle.

(11) The MTC may use the same PSS (primary synchronization signal) / SSS (secondary synchronization signal) / CRS (common reference signal) used in legacy LTE or NR. In the case of NR, PSS / SSS is transmitted in units of SS blocks (or SS / PBCH block or SSB), TRS (tracking RS) can be used for the same purpose as CRS. That is, TRS is a cell-specific RS and may be used for frequency / time tracking.

MTC operation mode and level

Next, the MTC operation mode and level will be described. MTC is classified into two operation modes (first mode and second mode) and four different levels to improve coverage, and may be as shown in Table 42 below.

The MTC operation mode may be referred to as a CE mode, in which case the first mode may be referred to as CE Mode A and the second mode may be referred to as CE Mode B.

The first mode is defined for small coverage enhancement in which full mobility and channel state information (CSI) feedback is supported, and is a mode in which there is no repetition or fewer repetitions. The operation of the first mode may be the same as the operation range of UE category 1. The second mode is defined for UEs in extremely poor coverage conditions that support CSI feedback and limited mobility, and a large number of repetitive transmissions are defined. The second mode provides up to 15 dB coverage enhancement based on the UE category 1 range. Each level of MTC is defined differently in RACH and paging procedure.

Let's take a look at MTC operation mode and how each level is determined.

The MTC operation mode is determined by the base station, and each level is determined by the MTC terminal. Specifically, the base station transmits RRC signaling including information on the MTC operation mode to the terminal. Here, the RRC signaling may be an RRC connection setup message, an RRC connection reconfiguration message or an RRC connection reestablishment message. Herein, the term of the message may be expressed as an information element (IE).

Thereafter, the MTC terminal determines the level in each operation mode and transmits the determined level to the base station. Specifically, the MTC terminal determines the level in the operation mode based on the measured channel quality (eg, RSRP, RSRQ, or SINR), and determines the base station using the PRACH resources (frequency, time, preamble) corresponding to the determined level. Inform level.

MTC guard period

As you can see, MTC operates in narrowband. The location of the narrowband may be different for each specific time unit (eg, subframe or slot). The MTC terminal tunes to a different frequency in every time unit. Therefore, all frequency retuning requires a certain time, which is defined as the guard period of the MTC. That is, the guard period is required when transitioning from one time unit to the next time unit, and transmission and reception do not occur during the corresponding time period.

The guard period is defined differently depending on whether it is downlink or uplink, and is defined differently according to the situation of downlink or uplink. First, the guard period defined in the uplink is defined differently according to the characteristics of data carried by the first time unit (time unit N) and the second time unit (time unit N + 1). Next, the guard period of the downlink requires (1) that the first downlink narrowband center frequency and the second narrowband center frequency are different, and (2) in TDD, that the first uplink narrowband center frequency and the second downlink center frequency are different.

Looking at the MTC guard period defined in Legacy LTE, at most for Tx-Tx frequency retuning between two consecutive subframes

A guard period of SC-FDMA symbols is generated. If the higher layer parameter ce-RetuningSymbols is set,

Is the same as ce-RetuningSymbols, otherwise

= 2. In addition, for the MTC terminal configured with the upper layer parameter srs-UpPtsAdd, a guard period of a maximum SC-FDMA symbol is generated for Tx-Tx frequency retuning between the first special subframe for the frame structure type 2 and the second uplink subframe. .

The MTC terminal that is powered on again or enters a new cell while the power is turned off performs an initial cell search operation such as synchronizing with the base station in step S1101. To this end, the MTC terminal receives a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station, synchronizes with the base station, and acquires information such as a cell ID. The PSS / SSS used for the initial cell search operation of the MTC may be a PSS / SSS of legacy LTE, a resynchronization signal (RSS), and the like.

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

Meanwhile, the MTC terminal may receive a downlink reference signal (DL RS) in an initial cell search step to check the downlink channel state. The broadcast information transmitted through the PBCH is a MIB (Master Information Block). In the MTC, the MIB is a subframe different from the first slot of subframe # 0 of the radio frame (subframe # 9 for FDD and subframe # 5 for TDD). Is repeated.

PBCH repetition is performed by repeating exactly the same constellation points in different OFDM symbols so that they can be used for initial frequency error estimation even before attempting PBCH decoding.

Five reserved bits in the MIB are used in the MTC to transmit scheduling information for a new system information block for bandwidth reduced device (SIB1-BR) including time / frequency location and transport block size.

SIB-BR is transmitted directly on the PDSCH without any control channel associated with it.

SIB-BR remains unchanged in 512 radio frames (5120 ms) to allow multiple subframes to be combined.

Table 43 is a table which shows an example of MIB.

In Table 43, the schedulingInfoSIB1-BR field represents an index of a table defining SystemInformationBlockType1-BR scheduling information, and a value of 0 indicates that SystemInformationBlockType1-BR is not scheduled. The overall functionality and information carried by SystemInformationBlockType1-BR (or SIB1-BR) is similar to SIB1 of legacy LTE. The contents of SIB1-BR may be classified into (1) PLMN, (2) cell selection criteria, and (3) scheduling information about SIB2 and other SIBs.

After completing the initial cell search, the MTC terminal may receive PDSCH according to the MPDCCH and the MPDCCH information in step S1102 to obtain more specific system information. MPDCCH is very similar to (1) EPDCCH, carries common and UE specific signaling, (2) can be transmitted only once or repeatedly (the number of repetitions is set by higher layer signaling), (3) Multiple MPDCCHs are supported and the UE monitors a set of MPDCCHs, (4) formed by a combination of enhanced control channel elements (eCCEs), each eCCE comprising a set of resource elements, and (5) RA-RNTI ( Radio Network Temporary Identifier (SI), SI-RNTI, P-RNTI, C-RNTI, temporary C-RNTI, and semi-persistent scheduling (SPS) C-RNTI are supported.

Thereafter, the MTC terminal may perform a random access procedure such as step S1103 to step S1106 to complete the access to the base station. The basic configuration related to the RACH procedure is transmitted by SIB2. In addition, SIB2 includes parameters related to paging. Paging Occasion (PO) is a subframe in which P-RNTI can be transmitted on the MPCCH. When the P-RNTI PDCCH is transmitted repeatedly, PO refers to the starting subframe of the MPDCCH repetition. The paging frame PF is one radio frame and may include one or multiple POs. When DRX is used, the MTC terminal monitors only one PO per DRX cycle. Paging NarrowBand (PNB) is one narrowband, the MTC terminal performs the paging message reception.

To this end, the MTC terminal may transmit a preamble through a physical random access channel (PRACH) (S1103) and receive a response message (RAR) for the preamble through the MPDCCH and the corresponding PDSCH ( S1104). In case of contention-based random access, the MTC terminal may perform a contention resolution procedure such as transmitting an additional PRACH signal (S1105) and receiving an MPDCCH signal and a corresponding PDSCH signal (S1106). The signal and / or messages (Msg 1, Msg 2, Msg 3, Msg 4) transmitted in the RACH procedure in the MTC may be repeatedly transmitted, and this repetition pattern is set differently according to the CE level. Msg 1 means PRACH preamble, Msg 2 means random access response (RAR), Msg 3 means UL transmission of the MTC terminal for the RAR, Msg 4 means DL transmission of the base station for Msg 3 can do.

For random access, signaling for different PRACH resources and different CE levels is supported. This provides the same control of the near-far effect on the PRACH by grouping together the UEs experiencing similar path loss. Up to four different PRACH resources may be signaled to the MTC terminal.

The MTC terminal estimates RSRP using downlink RS (eg, CRS, CSI-RS, TRS, etc.) and selects one of resources for random access based on the measurement result. Each of the resources for the four random accesses is related to the number of repetitions for the PRACH and the number of repetitions for the random access response (RAR).

Therefore, a bad coverage MTC terminal needs a large number of repetitions to be successfully detected by the base station, and needs to receive an RAR having a corresponding repetition number to satisfy their coverage level.

Search spaces for RAR and contention resolution messages are also defined in the system information and are independent for each coverage level.

In addition, the PRACH waveform used in the MTC is the same as the PRACH waveform used in legacy LTE (eg, OFDM and Zadof-Chu sequence).

After performing the above-described procedure, the MTC terminal receives a MPDCCH signal and / or a PDSCH signal (S1107) and a physical uplink shared channel (PUSCH) signal and / or physical uplink control as a general uplink / downlink signal transmission procedure. Transmission of a channel PUCCH signal may be performed (S1108). The control information transmitted from the MTC terminal to the base station is collectively referred to as uplink control information (UCI). The UCI may include HARQ-ACK / NACK, scheduling request (SR), channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI) information, and the like. have.

When the RRC connection to the MTC terminal is established, the MTC terminal blindly decodes the MPDCCH in a search space configured for obtaining uplink and downlink data allocation.

The MTC uses all of the OFDM symbols available in the subframe to transmit the DCI. Thus, time domain multiplexing between the control channel and the data channel in the same subframe is not possible. That is, as previously described, cross-subframe scheduling between the control channel and the data channel is possible.

The MPDCCH having the last repetition in subframe #N schedules PDSCH allocation in subframe # N + 2.

The DCI transmitted by the MPDCCH provides information on how repeated the MPDCCH is so that the MTC UE knows when the PDSCH transmission starts.

PDSCH allocation may be performed in different narrowbands. Therefore, the MTC terminal needs to retune before decoding the PDSCH assignment.

For uplink data transmission, scheduling follows the same timing as legacy LTE. Here, the last MPDCCH in subframe #N schedules PUSCH transmission starting at subframe # N + 4.

Legacy LTE allocation is scheduled using the PDCCH, which uses the first OFDM symbols in each subframe, and the PDSCH is scheduled in the same subframe as the subframe in which the PDCCH is received.

In contrast, the MTC PDSCH is cross-subframe scheduled and one subframe is defined between the MPDCCH and the PDSCH to allow MPDCCH decoding and RF retuning.

The MTC control channel and data channels may be repeated through a large number of subframes having up to 256 subframes for the MPDCCH and up to 2048 subframes for the PDSCH to be decoded under extreme coverage conditions.

MTC Cell Search

Hereinafter, the (initial) cell search procedure of the salping MTC in step S1001 of FIG. 18 will be described in more detail.

Cell search is a procedure by which a UE obtains time and frequency synchronization with a cell and detects a cell ID of that cell. E-UTRA cell discovery supports scalable total transmission bandwidth corresponding to 6 RB or more. PSS and SSS are sent on the downlink to facilitate cell search. If a resynchronization signal is sent on the downlink, it can be used to regain time and frequency synchronization with the cell. The physical layer uses synchronous signals to provide 504 unique cell IDs.

The UE searches for PSS / SSS in Center 6 PRB to obtain cell ID, subframe timing information, duplexing mode (time division duplex (TDD) or frequency division duplex (FDD)) and cyclic prefix (CP) length. PSS may use a ZCoff (Zadoff-Chu) sequence. For frame structure type 1 (ie, FDD), the PSS may be mapped to the last orthogonal frequency division multiplexing (OFDM) symbol of

slots

0 and 10. For frame structure type 2 (ie, TDD), the PSS may be associated with OFDM symbols in

subframes

1 and 6. SSS uses an interleaved concatenation of two length -31 binary sequences. The concatenated sequence is scrambled with the scrambling sequence given by the PSS. For FDD, SSS can be mapped to OFDM symbol number NsymbDL-2 in

slots

0 and 10, where NsymbDL is the number of OFDM symbols in the downlink slot. For TDD, the SSS can be mapped to OFDM symbol number NsymbDL-1 in

slots

1 and 11, where NsymbDL is the number of OFDM symbols in the downlink slot.

MTC's System Information Acquisition

Hereinafter, the procedure of obtaining system information of the salping MTC in step S1002 of FIG. 18 will be described in more detail.

21 shows a general system for a system information acquisition procedure.

When searching for a cell using PSS / SSS, the UE obtains system information (SI).

The UE applies a system information acquisition procedure to obtain access layer (AS) and non-access layer (NAS) system information broadcasted by the E-UTRAN. This procedure applies to the UE of RRC_IDLE and the UE of RRC_CONNECTED.

System information may be classified into a master information block (MIB) and various system information blocks (SIB). The MIB defines the most essential physical layer information of the cell needed to receive additional system information. The MIB is transmitted on the PBCH. SIBs other than System Information Block Type -1 (SIB1; SystemInformationBlockType1) are delivered in SI messages, and mapping SI information to SI messages can be flexibly configured by SchedulingInfoList included in SystemInformationBlockType1. Each SIB is included only in a single SI message. And at most once in that message; Only SIBs with the same scheduling requirements (periods) can be mapped to the same SI message; The system information block type -1 (SIB2; SystemInformationBlockType2) is always mapped to the SI message corresponding to the first item of the SI message list in the scheduling information list. Multiple SI messages can be sent in the same period. SystemInformationBlockType1 and all SI messages are sent on the DL-SCH. The BL UE and the UE of the CE apply the BR version of the SIB or SI message, for example.

The MIB uses a fixed schedule with a period of 40ms and an iteration within 40ms. The first transmission of the MIB is scheduled in subframe # 0 of the radio frame with SFN mod 4 = 0, and the repetition is scheduled in subframe # 0 of all other radio frames. For a TDD / FDD system with a bandwidth greater than 1.4 MHz that supports a BL UE or UE in CE, it is scheduled in subframe # 0 of the same radio frame and in subframe # 5 of the same radio frame for FDD and TDD.

SystemInformationBlockType1 contains relevant information when evaluating whether a UE can access a cell and defines the scheduling of other system information blocks. SystemInformationBlockType1 uses a fixed schedule with a period of 80 ms and an iteration within 80 ms. The first transmission of SystemInformationBlockType1 is scheduled in subframe # 5 of the radio frame with SFN mod 8 = 0, and repetition is scheduled in subframe # 5 of all other radio frames with SFN mod 2 = 0.

In the case of a BL UE or UE in the CE, a MIB to which additional repetition may be provided is applied, whereas for SIB1 and other SI messages, separate messages are used that are scheduled individually and with different content. Individual instances of SIB1 are named SystemInformationBlockType1-BR. SystemInformationBlockType1-BR includes information such as valid downlink and uplink subframes, maximum support for coverage enhancement, and scheduling information for other SIBs. SystemInformationBlockType1-BR is sent directly over the PDSCH without an associated control channel. SystemInformationBlockType1-BR uses a schedule with a period of 80ms. The transport block size (TBS) and repetition within 80 ms for SystemInformationBlockType1-BR are indicated in the MIRC through the scheduling information SIB1-BR or optionally in an RRCConnectionReconfiguration message that includes MobilityControlInfo. In particular, five reserved bits of the MIB are used to convey the reservation information for SystemInformationBlockType1-BR including time and frequency location and transport block size in the eMTC. The SIB-BR remains unchanged in 512 radio frames (5120 ms) to combine a large number of subframes.

The SI message is transmitted within a time domain window (called an SI window) that occurs periodically using dynamic scheduling. Each SI message is associated with an SI window and the SI windows of other SI messages do not overlap. That is, only the corresponding SI is transmitted within one SI- window. The length of the SI window is common to all SI messages and can be configured. Within the SI window, the corresponding SI message is a sub-channel # 5 of the multimedia broadcast multicast service single frequency network (MBSFN) subframe, the uplink subframe in TDD, and subframe # 5 of the radio frame with SFN mode. Can be sent multiple times in a frame. The UE obtains detailed time domain scheduling (and other information, eg, frequency domain scheduling, transmission format used) from the decoding system information radio network temporary identifier (SI-RNTI) on the PDCCH. In the case of a BL UE or a UE of CE, detailed time / frequency domain scheduling information for the SI message is provided in SystemInformationBlockType1-BR.

SystemInformationBlockType2 contains common and shared channel information.

MTC's Random Access Procedure

Hereinafter, a random access procedure of the salping MTC in steps S1003 to S1006 of FIG. 18 will be described in more detail.

The random access procedure is performed for the next event.

Initial access in RRC_IDLE;

-RRC connection reestablishment procedure;

Handover

DL data arrives during RRC_CONNECTED requiring a random access procedure;

UL data arrival during RRC_CONNECTED requiring a random access procedure;

-Positioning purpose of RRC_CONNECTED, which requires a random access procedure.

22 illustrates a contention based random access procedure.

The random access preamble (also called "Msg1") is transmitted on the PRACH. The UE randomly selects one random access preamble among the random access preamble set indicated by the system information or the handover command, and selects and transmits a PRACH resource capable of transmitting the random access preamble.

The physical layer random access preamble consists of a cyclic prefix of length TCP and a sequence portion of length TSEQ. The parameter values are listed in Table 44 below and may vary depending on the frame structure and random access configuration. The higher layer controls the preamble format.

MTC's DRX Procedure (Discontinous Reception Procedure)

While performing the above-described general signal transmission / reception procedure of the MTC, the MTC terminal is in an idle state (eg, RRC_IDLE state) and / or inactive state (eg, in order to reduce power consumption). RRC_INACTIVE state) may be switched to the state. In this case, the MTC terminal switched to the valid state and / or inactive state may be configured to use the DRX scheme. For example, the MTC terminal switched to the idle state and / or inactive state may perform monitoring of the MPDCCH related to paging only in a specific subframe (or frame, slot) according to the DRX cycle set by the base station or the like. Can be set. Here, the MPDCCH associated with paging may refer to the MPDCCH scrambled with P-RNTI (Paging Access-RNTI).

As shown in FIG. 23, the MTC UE in the RRC_IDLE state monitors only some subframes SF in relation to paging (ie paging, PO) in a subset of radio frames (ie, paging frame, PF). Paging is used to trigger an RRC connection and indicate a change in system information for the UE in RRC_IDLE mode.

In addition, DRX setting and indication for the MTC terminal may be performed as shown in FIG. 24.

24 shows an example of a DRX configuration and indication procedure for an MTC terminal. In addition, FIG. 24 is merely for convenience of description and does not limit the method proposed herein.

Referring to FIG. 24, the MTC terminal may receive DRX configuration information (DRX configuration information) from a base station (eg, NodeB, eNodeB, eNB, gNB, etc.) (S210). In this case, the MTC terminal may receive such information from the base station through higher layer signaling (eg, RRC signaling). Here, the DRX configuration information may include DRX cycle information, DRX offset, setting information on timers related to DRX, and the like.

Thereafter, the MTC terminal may receive a DRX command (DRX command) from the base station (S220). In this case, the terminal may receive such a DRX command from the base station through higher layer signaling (eg, MAC-CE signaling).

The MTC terminal receiving the above DRX command may monitor the MPDCCH in a specific time unit (eg, subframe, slot) according to the DRX cycle (S230). In this case, monitoring the MPDCCH may decode the MPDCCH for a specific region according to a DCI format (DCI format) to be received through the corresponding search region, and then scrambling the CRC to a predetermined RNTI value in advance. This can mean checking whether it matches (i.e. matches) the desired value.

When the corresponding MTC terminal receives the information indicating the change of its paging ID and / or system information in the MPDCCH through the procedure of FIG. 23 described above, initialize the connection (eg, RRC connection) with the base station ( Or reset) or receive (or obtain) new system information from the base station.

25 shows one example of a DRX cycle.

In FIG. 25, the DRX cycle specifies the period of inactivity and periodic repetition within the duration. The MAC entity may be configured by the RRC with DRX function to control the PDCCH monitoring activity of the UE for the RNTI (eg, C-RNTI) of the MAC entity. Thus, the MTC UE may monitor the PDCCH for a short period (eg, on duration) and stop monitoring the PDCCH for a long period (eg, an opportunity for DRX). If DRX is configured when in RRC_CONNECTED (ie, connected mode DRX, CDRX), the MAC entity may discontinuously monitor the PDCCH using the DRX operation specified below. Otherwise, the MAC entity may continuously monitor the PDCCH. In the case of MTC, PDCCH may refer to MPDCCH. For MTC, an extended DRX cycle of 10.24 seconds is supported on the RRC connection.

Abbreviation

Before looking at the method proposed in this specification, an abbreviation and definition of terms to be described later are summarized.

MIB-NB: masterinformationblock-narrowband

SIB1-NB: systeminformationblock1-narrowband

CRS: cell specific reference signal or common reference signal

ARFCN: absolute radio-frequency channel number

PRB: physical resource block

PRG: precoding resource block group

PCI: physical cell identifier

N / A: non-applicable

EARFCN: E-UTRA absolute radio frequency channel number

RRM: radio resource management

RSRP: reference signal received power

RSRQ: reference signal received quality

TBS: transport block size

TDD / FDD: time division duplex / frequency division duplex

Definition

NB-IoT: The NB-IoT provides access to network services via E-UTRA with a channel bandwidth limited to 200 kHz.

NB-IoT In-Band Operation: The NB-IoT operates in-band when using resource block (s) within a normal E-UTRA carrier.

NB-IoT guard band operation: The NB-IoT operates in guard band when using resource block (s) not used within the guard band of the E-UTRA carrier.

NB-IoT standalone operation: NB-IoT operates standalone when using its spectrum. For example, the spectrum currently used by the GERAN system on behalf of one or more GSM carriers and the spectrum scattered for potential IoT deployment.

Anchor carrier: In NB-IoT, a carrier assumes that NPSS / NSSS / NPBCH / SIB-NB or NPSS / NSSS / NPBCH is transmitted for TDD.

Non-anchor carrier: In NB-IoT, a carrier that does not assume that the terminal transmits NPSS / NSSS / NPBCH / SIB-NB or TSS for TDD or NPSS / NSSS / NPBCH.

Channel raster: The minimum unit from which a terminal reads a resource. In the case of an LTE system, the channel raster has a value of 100 kHz.

Also, '/' described herein may be interpreted as 'and / or', and 'A and / or B' may have the same meaning as 'including at least one of A or (and / or) B'. Can be interpreted.

<본 발명의 실시예><Example of the present invention>

The present invention relates to a method of utilizing a legacy LTE control area that was not used in the conventional LTE-MTC when the standalone operation of MTC.

In the present invention, LTE-MTC supporting only conventional LTE in-band operation is referred to as eMTC, MTC supporting standalone operation is referred to as sMTC, and legacy LTE is referred to as LTE. Since the sMTC cell has no obligation to support the control region for the conventional LTE UE, this part can be used for the following purposes for the sMTC service. The present invention proposes a method of utilizing the LTE control region in the sMTC system for the above purpose.

1. First Embodiment: Method of Using LTE Control Region for Improving Performance

According to the first embodiment, the RS is transmitted to the LTE control region to improve channel estimation and / or synchronization or measurement performance or to further improve MPDCCH / PDSCH performance by lowering the code rate by additionally transmitting MPDCCH / PDSCH data. Can be.

(1) Embodiment 1-1: Method of Transmitting RS

Embodiment 1-1 may refer to a method in which a base station transmits a cell-specific RS such as a CRS (in addition to a CRS understood by an LTE or eMTC terminal) to an LTE control region.

The added RS can be used for improving MPDCCH / PDSCH channel estimation performance or for improving measurement accuracy such as RSRP / RSRQ.

The base station may transmit UE specific DMRS. DMRS is basically scheduled for the purpose of improving channel estimation and / or synchronization performance of the MPDCCH / PDSCH used for a specific purpose by using the LTE control region configured to transmit the MPDCCH / PDSCH in the time / frequency region to which the MPDCCH / PDSCH is transmitted. The DMRS corresponding to the corresponding MPDCCH / PDSCH subframe (n) may be transmitted in the LTE control region of the preceding subframe (s) (for example, subframe (n-1), (n-2), ...).

The base station may transmit a burst sync signal such as a resynchronization signal (RSS) to the LTE control region or a wake-up signal (WUS) at this location.

The UE checks both the WUS and the MPDCCH in the corresponding subframe. If the WUS is detected and the MPDCCH has not been detected yet, the UE continuously monitors the MPDCCH. If the WUS is not detected until the max duration, the MPDCCH monitoring can be stopped.

(2) Embodiment 1-2: Method of Lowering Code Rate of MPDCCH / PDSCH Data

In terms of data, the base station may use the LTE control region for the purpose of transmitting MPDCCH / PDSCH data RE. Data RE is rate matching the data RE to the part except for the above RS (including all the above-described additional RS as well as the RS which the LTE or eMTC terminal can understand), or the RS puncturing the data RE. It is possible to map data RE.

The base station may be a part of the MPDCCH / PDSCH OFDM symbols (in the same slot or subframe or adjacent subframe) so that the base station can be used in the receiver for coherent combining between original and frequency tracking and and / or OFDM symbols. CRS (as understood by LTE or eMTC terminal) or a symbol containing a minimum of RE that can be duplicated in the above-described additional RS position, or may preferentially select a symbol that does not include RS. In addition, the selected 'some' symbols may vary according to the number of symbols included in the control region).

At this time, even if the base station transmits the CRS to the LTE control region even though it is not LTE in-band so as not to affect the eMTC operation, the base station can copy data to the LTE control region and puncturing with the CRS. In order to ensure that the data REs in the copied OFDM symbol all obtain a similar combining (SNR) gain, that is, to avoid the case where some data REs do not obtain the combining (SNR) gain by CRS puncturing, the base station of the LTE control region is It is possible to preferentially copy OFDM symbols in which a CRS exists at the same position as the CRS position.

The above method may be referred to as a "CRS transmission symbol first copy method." The above method may be a method of first copying the CRS transmission symbol (s) having the same CRS RE position as the CRS RE position transmitted to the LTE control region. This has the advantage of minimizing puncturing.

In the above method, if the base station is normal CP, the symbol index in the subframe is l.

And, if the number of symbols in the LTE control region is L, it may be to copy as follows according to the number of control region.

(1) for normal CP: l

If L = 1, l = {7} → l = {0} (A → B indicates to copy A to B)

If L = 2, l = {7,8} → l = {0,1}

If L = 3, l = {7,8,9} or {7,8,6} → l = {0,1,2}

Both methods are possible, but l = {7,8,6} → l = {0,1,2} is advantageous in terms of latency.

If L = 4, l = {7,8,9,10} or {7,8,9,6} or {7,8,5,6} → l = {0,1,2,3}

All three methods are possible, but l = {7,8,5,6} → l = {0,1,2,3} is most advantageous in terms of latency.

(2) for extended CP:

If L = 1, l = {6} → l = {0}

If L = 2, l = {6,7} → l = {0,1}

If L = 3, l = {6,7,8} or {5,6,7} → l = {0,1,2}

Both methods are possible, but l = {5,6,7} → l = {0,1,2} is advantageous in terms of latency.

(3) For MBSFN subframe:

In the case of the MBSFN subframe, the CRS cannot be expected in the MBSFN region, but the base station applies a similar method to the above, in which the SFSFN RS or DMRS overlapping the CRS is present in chronological order or in the MBSFN RS overlapping the CRS. Alternatively, DMRSs may be preferentially copied and transmitted to the LTE control region in order of increasing number of DMRSs.

In the former case, for example, two OFDM symbols having l = {2} and l = {10} satisfy the above condition and are copied in the form l = {2,10} → l = {0,1}. In this situation, if L = 1, l = {2} → l = {0} or l = {10} → l = {0}.

Both methods are possible, but the former has an advantage in terms of latency compared to the latter.

The above methods are not limited to the same subframe or slot, but apply equally to adjacent subframes or slots. That is, the base station may copy (or RE mapping) the MPDCCH / PDSCH of the subframe #N or a part thereof to the LTE control region of the subframe # N + 1 or # N-1.

In addition, in the above method, when MPDCCH / PDSCH is not transmitted to a corresponding subframe (subframe #N) as in the case of a TDD special subframe configuration 0/5 or an MBSFN subframe, a DL subframe (subframe #N) immediately before the adjacent MPDCCH / PDSCH is transmitted. MPDCCH / PDSCH of -1) or a part thereof may be applied by copying (or RE mapping) to the LTE control region of TDD special subframe configuration 0/5 (subframe #N) which cannot transmit MPDCCH / PDSCH.

Also for the LTE control region of the MBSFN subframe in which the MPDCCH / PDSCH is not transmitted, similar to the above method, the base station may copy or REmap the MPDCCH / PDSCH of an adjacent MPDCCH / PDSCH transmission DL subframe or a part thereof to be transmitted. .

The base station is separate from, or additionally, methods considering the use of frequency tracking and coherent combining between and / or OFDM symbols, in order to minimize latency or for services such as URLLC where latency is important, to be closest to the LTE control region. OFDM symbols can be copied.

The base station may consider a method of first copying the RS transmission symbol. In the RS-first transmission method, the base station copies RS instead of random data, so that more samples (ie, RE) can be used for frequency tracking for frequency tracking, or the channel estimation accuracy can be improved using additional RS. You can get it.

For example, the RS may be a CRS. In this case, the base station may additionally expect the gain described in the CRS transmission symbol priority copy method. The RS may also be, for example, DMRS, which is referred to as DMRS transmission symbol first copy method. The channel estimation DMRS transmission symbol priority copy method may consider a method in which an RS transmission base station first copies a symbol. In the RS-first transmission method, the base station copies RS instead of random data, so that more samples (ie, RE) can be used for frequency tracking for frequency tracking, or the channel estimation accuracy can be improved using additional RS. You can get it.

RS may be, for example, CRS. In this case, the base station may additionally expect the gain described in the CRS transmission symbol priority copy method. The RS may also be, for example, DMRS, which is called a method in which the base station first copies the DMRS transmission symbol. DMRS transmission symbol first copy method has an advantage that the base station can additionally obtain channel estimation by using the DMRS signal copied to the LTE control region. In addition, if the DMRS is power boosted, the gain in terms of sync due to the increased SNR of the DMRS RE can be expected additionally.

In case of copying RE mapping part of MPDCCH to LTE control region, part of MPDCCH copying and RE mapping may be defined by one or a plurality of OFDM symbol (s) on the time axis, and one or more on the frequency axis. It may be defined or defined by multiple PRB (s).

Here, the OFDM symbol (s) defined on the time axis may be defined by a combination of OFDM symbol indexes. For example, in the CRS transmission symbol priority copy method, the OFDM symbol index (s) defined on the time axis includes a CRS transmission RE having the same subcarrier index as the subcarrier indexes of the CRS transmission REs in the LTE control region. It may be an OFDM symbol index (es) of an MPDCCH OFDM symbol (s) (OFDM symbols containing CRS REs of the same subcarrier indexes as those of CRS REs in the LTE control region).

It may be an OFDM symbol index (s) of an OFDM symbol (s) including DMRS transmission REs. MPDCCH REs mapped to the LTE control region may be limited to one or a plurality of PRB (s) regions defined or defined in the frequency axis, and may be REs satisfying the following conditions.

-REs used for MPDCCH transmission

-REs containing reference signals (e.g., CRS, DMRS) in the PRBs used for MPDCCH transmission

-REs not colliding with CRS REs in the LTE Control Area after they are mapped into the LTE Control Area

i.e., REs not having the same subcarrier indexes as those of CRS REs in the LTE control area.

-REs puncturing MPDCCH transmission REs (e.g., PSS, SSS, PBCH, CSI-RS)

REs defined to puncturing MPDCCH transmission REs as described above may be included in MPDCCH REs mapped to the LTE control region. In this case, since the REs defined to puncturing MPDCCH transmission REs are known signals, the signals can be used for sync or channel estimation.

As described above, the base station may exclude the REs defined to puncturing MPDCCH transmission REs from the MPDCCH REs mapped to the LTE control region. In this case, instead of the REs puncturing the MPDCCH transmission RE, the puncturing MPDCCH transmission REs are copied to the LTE control region and mapped to the RE.

In this case, the number of identical REs between the LTE control region and the MPDCCH in the same subframe may be reduced, which may have a disadvantage in terms of sync. Using the same point in the LTE control region can be expected to improve performance through averaging or combing gain.

The base station copies some OFDM symbol (s) of the MPDCCH or PDSCH symbol (s) to the LTE control region for the frequency tracking, or some OFDM symbol (s) of the MPDCCH or PDSCH symbol (s). In order to obtain an advantage in terms of frequency tracking from the copying method to the LTE control region, the corresponding MPDCCH or PDSCH transmission should be predictable from the terminal.

That is, the terminal can obtain the frequency tracking gain by repetition of the OFDM symbol (s) only when the terminal can know the MPDCCH or PDSCH transmission time deterministically. Otherwise, if the terminal does not know when to transmit the MPDCCH or PDSCH, or if the terminal needs to be blind detection and / or decoding in order to confirm the transmission of the MPDCCH or PDSCH only with information on the transmission time, (actual transmission is made If not supported or the above method is not applied), the wrong estimate may make reception impossible.

For the above reason, a method of copying some OFDM symbol (s) of the MPDCCH or PDSCH symbol (s) to the LTE control region for frequency tracking purposes, such as the MPDCCH and / or PDSCH for broadcast transmission, in terms of UE If the transmission time can be determined deterministically (deterministic transmission or deterministic scheduling) can be applied.

In order to obtain an advantage in terms of frequency tracking from the method of copying some OFDM symbol (s) of the MPDCCH or PDSCH symbol (s) to the LTE control region, the above method may be used as MPDCCH and / or PDSCH for broadcast transmission. The base station may be applied to the case where the transmission time can be deterministically determined from the UE's point of view (deterministic transmission or deterministic scheduling). In the case where the transmission time can be determined deterministically from the UE's point of view (deterministic transmission or deterministic scheduling), for example, the UE can periodically know, for example, MPDCCH and / or PDSCH for PBCH or SIB and / or SI messages transmission. It may include a channel transmitted (repeatedly) at a point in time.

For the above reason, the method of copying some OFDM symbol (s) of the MPDCCH or PDSCH symbol (s) to the LTE control region is limited to the case where the transmission time can be determined deterministically from the UE perspective (deterministic transmission or deterministic scheduling). In other cases, that is, in case of transmission that cannot be deterministically determined from the UE's point of view, the following MPDCCH or PDSCH rate matching method is applied, or a MPDCCH or PDSCH symbol designed for a purpose other than frequency tracking ( To copy some OFDM symbol (s) to the LTE control region (eg, to first copy OFDM symbols having CRS at the same position as the CRS position of the LTE control region to the LTE control region). Can be.

The MPDCCH or PDSCH rate matching method is a method in which a base station sequentially maps coded bits from an LTE control region (R1) to frequency first RE (R1-> R2 RE mapping method), or coded bits for backward compatibility with legacy or data sharing. In this case, the frequency first RE mapping may be sequentially performed on the MPDCCH or PDSCH transmission region, and the remaining coded bits (which may be additional parity bits) may be sequentially performed on the LTE control region (R2 → R1). RE mapping method).

The part copied or mapped to the LTE control region may be part of coded bits or modulation symbols of MPDCCH / PDSCH or MPDCCH / PDSCH transmission REs.

In addition, when MPDCCH / PDSCH is repetition, in order to maximize coherent combining between subframes, the base station equally repetitions up to the LTE control region or when OFDM symbols copied from the MPDCCH / PDSCH to the LTE control region consider the total number of repetitions. In order to be as even as possible, the OFDM symbol may be changed every repetition or every repetition unit. The set of OFDM symbol (s) that is copied and repeated in the LTE control region may be determined in conjunction with MPDCCH / PDSCH repetition number and / or repetition index (i_rep).

For example, the LTE control region is composed of the first three OFDM symbols (i = 0,1,2) of the subframe, and the MPDCCH / PDSCH OFDM symbols are then 11 OFDM symbols (i = 3,4,5,6). When configured as (7,8,9,10,11,12,13), the OFDM symbol index in the MPDCCH / PDSCH copied to the LTE control region according to the MPDCCH / PDSCH repetition number may be determined as follows.

Example 1) Repetition number = 4 (i_rep = 0,1,2,3)

i_rep = 0: {3,4,5}; i_rep = 1: {6,7,8}; i_rep = 2: {9,10,11}; i_rep = 3: {12,13,3}

Example 2) Repetition number = 8 (i_rep = 0,1,2,3,4,5,6,7)

i_rep = 0: {3,4,5}; i_rep = 1: {3,4,5}; i_rep = 2: {6,7,8}; i_rep = 3: {6,7,8}

i_rep = 4: {9,10,11}; i_rep = 5: {9,10,11}; i_rep = 6: {12,13,3}; i_rep = 7: {12,13,3}

In example 1), the set of OFDM symbol (s) copied and repeated to the LTE control region is configured to include MPDCCH / PDSCH OFDM symbols as uniformly as possible within the repetition number, and when the repetition number is sufficient as in Example 2) In addition, a set of OFDM symbol (s) is configured to enable (OFDM) symbol level combining between adjacent subframe (s).

The above example may be a different value depending on the number of symbols and the number of repetitive transmissions included in the control region, and may be similarly applied as a value for maximally avoiding symbols overlapping between repetitive transmissions.

The LTE control region using methods may be differently applied according to 1) repetition number and / or CE mode, 2) frequency hopping, and 3) RV cycling.

The LTE control region RE mapping method according to repetition number and / or CE mode will be described. As described above, since the effects may vary depending on the repetition number as described above, it may be determined in conjunction with the repetition number.

Since the range of supported repetition numbers differs according to the CE mode, the above methods may be applied differently according to the CE mode. For example, since CE mode B mainly includes coverage expansion through repetition gain, example 2) above is applied only to a terminal operating in CE mode B, and a terminal operating in coverage mode A is described in Example 1 above. ) Can be used.

When the example 2) is applied to a terminal operating in CE mode B, the base station can perform (OFDM) symbol level combining so that the interval X in which the set of OFDM symbol (s) copied to the LTE control region remains the same is the channel. This can be determined by taking into account the coherence time. X may be a subframe unit or a slot unit.

An LTE control region RE mapping method according to frequency / narrowband hopping will be described below. (OFDM) Symbol level combining is possible, so that the interval X where the set of OFDM symbol (s) copied to the LTE control region remains the same is meaningful only in the same frequency / narrowband hop. It can be determined according to whether or not. For example, when the frequency hopping is 'on', the base station determines that gain due to symbol level combining is small, and applies a method of copying different parts without repetition as in Example 1) above, or (frequency / The size of the interval X can be determined according to the hop length. At this time, the range of the value of the interval X is from 1 to the number of subframes or slots in the hop, and X = 1 may mean a case of copying different parts without repetition as in Example 1).

An LTE control region RE mapping method according to RV cycling will now be described. (OFDM) The interval X in which the set of OFDM symbol (s) copied to the LTE control region is maintained to be the same because the symbol level combining is possible, may be a value limited by the RV cycling period when RV cycling is applied.

In addition, the LTE control region RE mapping method according to RV cycling may be a method determined in conjunction with the CE mode. For example, when a terminal operating in CE mode A is configured to cause RV cycling at every repetition, the repetition gain cannot be obtained, and thus the base station can operate by applying the above example 1).

The terminal operating in CE mode B may be configured to have the same RV for a certain period Z. The interval X value is calculated by configure or the terminal to have a value equal to or less than the Z value, or by referring to the Z value as an X value. Can be calculated.

Methods using the LTE control region in the above repetition (e.g., copy or map a different part for every repetition or a specific repetition unit, or copy or map the same part for all repetitions) are UE-specific Or it may be set semi-statically through cell-specific RRC signaling. For example, in the case of the method of copying or mapping the OFDM symbol (s) including the CRS, when the CRS transmission port is 2 or more, the positions of the CRS transmission REs having the OFDM symbol index 0 and the 3 are the same. (eg, different CRS transmission symbols) to allow the base station to copy different parts according to the number of CRS transmission ports (that is, 2 or more), or higher layer signaling as described above. Can be set through

When re-mapping the LTE-MTC MPDCCH / PDSCH to the LTE control region in frame structure type 2 (TDD), the base station includes the PSS in order to protect the PSS located at symbol index l = 2 of the TDD special subframe. Even if the MPDCCH / PDSCH start symbol lstartsymbol> 2, the MPDCCH / PDSCH may not be copied or RE mapped to the position of the PSS (ie, the position of the symbol index l = 2).

Example) Special subframe capable of transmitting MPDCCH / PDSCH (e.g., special subframe configuration # 4)

In the case of lstartsymbol = 3 and normal CP, when the OFDM symbols corresponding to the

OFDM symbol indexes

7,8, and 9 are copied or RE mapped to the

OFDM symbol indexes

0, 1, and 2, respectively, they collide with the PSS. In this case, the base station may apply the above method to copy or RE map OFDM symbols corresponding to the

OFDM symbol index

7, 8 to the

OFDM symbol index

0, 1 except for the OFDM symbol index 9. In the case of PDSCH, the base station may exclude from rate-matching.

In the case of lstartsymbol = 3 and extended CP, when the OFDM symbols corresponding to the

OFDM symbol indexes

6, 7, 8 are copied or RE mapped to the

OFDM symbol indexes

0, 1, and 2, respectively, the collision occurs with the PSS. In this case, by applying the above method, the base station may copy or RE map OFDM symbols corresponding to

OFDM symbol indexes

6 and 7 to

OFDM symbol indexes

0 and 1, except for OFDM symbol index 8. In the case of PDSCH, the base station may exclude from rate-matching.

More generally, when the TB scheduling unit is not a subframe or a slot, for example, when the minimum unit of scheduling is N subframes or slots in time by applying an uplink sub-PRB, the above operation is a unit of a subframe or slot. It may be in units of N subframes or slots. In the above operation, when 1 TB is divided into a plurality of M RUs and a temporal length of one RU is K subframes or slots, since 1 TB is transmitted over M * K subframes or slots, a unit of M * K subframes or slots is used. This includes operating with

(3) Embodiment 1-3: PBCH Expansion Method

The base station may extend or copy all or part of the OFDM symbol (s) of the PBCH (composed of 4 OFDM symbols) to the LTE control region to improve performance of the PBCH.

Here, the base station may determine the pattern of the PBCH (or the copy pattern of the PBCH) or the number of repetitions of the PBCH based on the method of transmitting / receiving the PBCH. That is, the base station may configure the pattern for copying some OFDM symbol (s) of the PBCH, for example, for correcting a performance difference due to a difference in the PBCH pattern between TDD / FDD. For example, in the case of FDD, the base station may copy all four OFDM symbols constituting the PBCH included in the 4 PBCH repetitions in the same manner. On the other hand, in TDD, the base station may repeatedly copy two OFDM symbols out of four OFDM symbols constituting the PBCH five times and copy the other two OFDM symbols three times.

If it is not necessary to assume the CRS in the LTE control region in the sMTC, the base station can be configured more freely.

FIG. 26 shows a diagram in which 4 PBCH repetitions are applied in eMTC. FIG.

As illustrated in FIG. 26, an OFDM symbol mapped with four PBCHs may be included in at least one symbol of a slot of a second subframe.

As shown in FIG. 27, the LTE control region may be a control region for the terminal. In this case, the base station includes first at least one first REs used for the first PBCH in at least one first symbol included in a second slot of a first subframe among the plurality of REs. It may be copied to at least one second symbol included in the first slot of the subframe.

In addition, the method of extending the PBCH by the base station in the LTE control region may be used to reinforce that the frequency estimation performance may be relatively weak compared to the FDD when the PBCH is used in TDD in the eMTC.

Specifically, in eMTC, frequency tracking performance can be improved by repetition between OFDM symbols while PBCH repetition is placed in subframes # 0 and # 9 in FDD, but TDD supports PBCH repetition in all TDD U / D configurations. In order to do this, we had to place PBCH repetition in subframes # 0 and # 5, so we could not gain in terms of frequency tracking performance as much as FDD.

FIG. 28 shows a second example (example 2) of a method for extending a PBCH to an LTE control region for an sMTC UE proposed in the present invention, and FIG. 29 to extend a PBCH to an LTE control region for an sMTC UE proposed in the present invention. The third example of the method (Example 3) is shown.

As shown in FIG. 28 and FIG. 29, the base station configures the BPCH configuration symbols extended from the TDD to the control region to be equally spaced from the same repeated PBCH OFDM symbols, thereby being most advantageous in terms of frequency tracking performance. Can be placed. The above examples are arrangements satisfying two applications, one for correcting a performance difference due to a difference in PBCH pattern between TDD / FDD and one for reinforcing frequency estimation performance in TDD.

Alternatively, in order to reduce the BPCH detection delay time of the terminal, the base station may transmit some of the encoded bits to be included in the next PBCH transmission subframe or some of the PBCH OFDM symbols, that is, in the control region of the nth PBCH transmission subframe The base station may transmit a part of information of the (n + 1) to (n + 3) th PBCH transmission subframe. This is to allow the terminal to try to detect at the lowest PBCH code rate in one subframe. In addition, the base station may be configured to transmit a portion of the encoded bits to be included in the PBCH transmission subframe or some of the PBCH OFDM symbols to the LTE control region of the subframe (s) following the PBCH transmission subframe.

2. Second Embodiment: Method of Using LTE Control Region to Improve Data Transmission Speed

The base station may use the LTE control region for MPDCCH / PDSCH data transmission to improve the data transmission rate. In this section, for convenience, the LTE control region is referred to as R1 and the MPDCCH / PDSCH region is referred to as R2. As a method for improving the data transmission speed, a method of encoding (channel coding) the data transmitted to R1 and the data transmitted to R2 into a single part and a method of encoding into two parts may be considered. In addition, the methods proposed below are not limited to applications for improving data transmission speed, and may be used as methods for improving performance. For example, when additional parity information for error correction is transmitted to R2, the methods proposed below may be classified as LTE control region utilization methods for performance improvement.

(1) Embodiment 2-1: Single part encoding for sMTC data rate enhancement

In the single part encoding method, the base station configures the channel coding input into a single part based on the REs in the region including R1 and R2 for sMTC data rate enhancement, and generates the coded bits by rate matching in the channel coding step. Rate-matched coded bits are RE mapped to R1 and R2 through modulation (e.g., QPSK, 16QAM, etc.).

In the RE mapping of the single part encoding method, the base station may perform frequency-first time-second RE mapping in the order of R1 → R2 without considering data sharing with the eMTC. In the above method, since RE mapping is performed in the input order, the buffer required for changing the order at the RE mapping input stage is unnecessary, or the required buffer size is small.

Alternatively, the base station may first map systematic bits among the coded bits to R2 in consideration of data sharing with the eMTC, and then remap the remaining coded bits to R1. Through the above RE mapping method, decoding can be performed independently using only R2. However, when both R1 and R2 are used, the code rate is lowered and reception can be performed at a relatively low SNR. In addition, the sMTC and the eMTC receive essential data through R2, but in the case of sMTC, additional information is received by receiving some kind of auxiliary data through R1 or additional redundancy data through R1, so that the terminal is lowered. Essential data can also be received in the SNR region.

In order to enable the sMTC UE to receive data of R2 or R1 and R2 by the single part encoding method, the base station receives corresponding information (for example, whether to receive both R1 and R2, RE mapping method, etc.) Signaling through higher layer configuration or scheduling DCI.

(2) Embodiment 2-2: Two part encoding for sMTC data rate enhancement

The two part encoding method independently encodes data to be transmitted through R2 and data to be transmitted through R1. If the part that is RE mapped to R1 is part 1 and the part that is RE mapped to R2 is part 2, and each code rate is C1 and C2, the base station bases on the number of (available) REs of C1 and R1 for part 1 Rate matching is performed, and rate matching is performed on part 2 based on the number of available REs of C2 and R2. C1 and C2 may be data of different characteristics, and thus may be independently configured. For example, the eMTC and the sMTC may commonly receive common data having a code rate C2 through R2, and the sMTC may receive sMTC dedicated data having an independently encoded code rate C1. In such a case, the UE may not receive an HARQ process ID or support HARQ-ACK feedback for independent data of R1. In addition, resource allocation information (eg, MCS, TBS, etc.) of R1 may be indirectly derived from scheduling information of the R2 part. If the R2 part also supports HARQ retransmission, it may be dependent on the R2 part. The HARQ ID may be set to the same value, or the detection result of the R1 and R2 parts may be combined to be HARQ-ACK feedback, or may be an R2 part in a corresponding subframe or slot using one HARQ ID and an additional 1 bit indication. It may be used to distinguish whether it is an R1 part, and may be transmitted to DCI.In addition, when frequency retuning is required, the R1 interval may be allowed to be used as a guard time.

The payload bits transmitted through R2 and the payload bits transmitted through R1 may be encoded by different channel coding methods due to the difference in payload size (or code block size thereof) between the two. For example, the base station encodes payload bits transmitted to R2 by LDPC or turbo coding method optimized for large payload size or code block size, and payload bits transmitted to R1 are more suitable for small payload size or code block size. It can be encoded by muller code or polar coding method.

Whether two-part encoding (including same or different channel coding) can be received may be defined and reported in the form of UE capability. The two part encoding for sMTC data rate enhancement method may be a method of applying to a capable UE according to the reported UE capability. The Capable UE may perform simultaneous decoding using two decoders in order to reduce latency in the case of two part ending.

The data transmitted to R1 may be common information to sMTC UEs, or may be information such as broadcast information, SC-PTM information, paging, Msg2 / 4 during random access, and the like. In addition to the MPDCCH / PDSCH data transmitted to R2, the data transmitted to R1 may be simultaneously received.

If the LTE control region is used for MPDCCH / PDSCH data transmission (or the LTE control region is extended to rate-matching), if the maximum code rate of the MPDCCH / PDSCH data is maintained, the base station theoretically increases due to the increase in the number of REs. Higher TBS allocation is possible. In this regard, when a TBS is newly defined or an additional TBS size is defined and supported, a terminal configured to expect MPDCCH / PDSCH transmission in an LTE control region may calculate TBS differently.

When the area in which DL or UL transmission is possible increases or decreases in the LTE subframe, the base station / terminal may use the TBS value calculated through the number of MCS and PRBs. For example, when the area capable of transmitting DL or UL increases or decreases, the base station / terminal determines the scaling factor X according to the increase or decrease rate, and the scaling factor X is determined through the TBS table lookup using the number of MCSs and PRBs. The TBS value obtained by multiplying the obtained TBS may be used as the TBS value, or the value on the TBS table closest to the new TBS may be applied when the TBS value is processed. The purification process may be operations such as round / floor / ceiling. If the value on the nearest TBS table is greater than 1, a larger TBS value may be selected or, conversely, a smaller value may be selected. When the TBS value after multiplying the scaling factor X is TBS ', when the TBS' value is larger than the TBS size (e.g., 1000 bits) allowed by the LTE MTC, 1000 bits are selected. That is, min (1000, TBS ') may be selected. For example, the method may be effective when the number of OFDM symbols capable of PDSCH transmission is small (e.g., special subframes). In this case, since the number of OFDM symbols capable of PDSCH transmission of a special subframe is smaller than that of a normal subframe, if Y is a parameter for scaling TBS, Y may be multiplied by X.

Alternatively, a terminal configured to expect MPDCCH / PDSCH transmission in the LTE control region may calculate a repetition differently or receive a repetition value different from eMTC. For example, when the LTE control region is used for performance improvement, when the LTE control region is used as a method of transmitting 3.1.1 RS and / or lowering the code rate of 3.1.2 MPDCCH / PDSCH data. The base station may allow the terminal to apply as few repetitions as performance is improved. As a method of applying a new repetition, the base station sets a new value different from the existing eMTC, or calculates a repetition value to be actually applied from the terminal configured to expect MPDCCH / PDSCH transmission in the LTE control region equal to the eMTC You can do that. As a method of calculating, for example, the base station may multiply a specific value (e.g., a scaling factor inversely proportional to the degree of performance improvement) from a value set in the same manner as the eMTC and integerize it through an operation such as floor / round / ceil. In addition, in order to enable the sMTC UE to receive data of R2 or R1 and R2 by the two part encoding method, the base station receives corresponding information (eg, receiving both R1 and R2 above, RE mapping method, encoding). Information, etc.) to the terminal through higher layer configuration or scheduling DCI.

As in the single part encoding method, the base station allows the sMTC UE to receive a single data unit only through R2 or through R1 and R2 (or only through R1). Whether data is transmitted using R2 or both R1 and R2) is signaled through higher layer configuration or scheduling DCI.

When the base station uses the LTE control region (using single-part encoding or two-part encoding) for PDSCH data transmission (or extends the LTE control region to rate-matching), the base station and the sMTC UE (legacy) In case of supporting data sharing with the eMTC UE, the redundancy version (RV) value according to the repetition of the sMTC UE and the starting position in the circular buffer corresponding to the RV may always have the same value as the eMTC UE. In this method, the base station configures one or a plurality of circular buffers based on the entire coded bits transmitted to R1 and R2 for the sMTC UE and determines the starting position in the circular buffer at a predetermined ratio of each configured circular buffer size. Rather, one or a plurality of circular buffers may be configured based on coded bits transmitted to R2, and a starting position of the circular buffer may be determined at a predetermined ratio of each configured circular buffer size.

When the LTE control region is used for PDSCH data transmission (using single-part encoding or two-part encoding) (or when the LTE control region is extended to rate-matching), the sMTC UE and the (legacy) eMTC UE In case of not supporting data sharing with, the starting position in the redundancy version (RV) value according to the repetition of the sMTC UE and the circular buffer corresponding to the corresponding RV may have a value different from that of the eMTC UE. For example, in this method, the base station / terminal configures one or a plurality of circular buffers based on the entire coded bits transmitted to R1 and R2 for the sMTC UE and starts at the circular buffer at a ratio of each configured circular buffer size. May be to determine a location.

In the above method, when the LTE control region is used to transmit PDSCH data, the base station / terminal may independently operate a circular buffer for R1 and R2. At this time, if each circular buffer corresponding to R1 and R2 are CB1 and CB2, CB2 has the same size as the circular buffer of eMTC. If the circular buffer of the eMTC consists of a Nrow X Ncolumn matrix, for example fixed at Ncolumn = 32, and Nrow is determined by Ncolumn and channel coding output bit stream size, then sMTC CB2 has the same Nrow X Ncolumn size as eMTC. Fill the dummy bit (if necessary) in the same way as eMTC. The circular buffer corresponding to PDSCH data added by using the LTE control region has the same Ncolumn value as CB2, and the Nrow value is determined according to the amount of data added. When the base station / terminal configures the circular buffer as Nrow X Ncolumn matrix, the read-out start column value of the circular buffer matrix is determined according to the RV value (eg, read-out start corresponding to RV0, RV1, RV2, and RV3). The column value is 2, 26, 50, 74), and the read-out start column value on the circular buffer according to the RV value of CB1 may have the same value as CB2.

When independent retransmission of PDSCH data is supported in R1 and R2, HARQ-ID and / or RV values for R1 and R2 data may be operated independently in the same subframe or slot. At this time, in order to reduce DCI signaling overhead, initial transmission of R1 data applies RV values (HARQ-ID and RV) of R2 of the same subframe, but when retransmission, the same RV value as initial transmission is applied or a specific value (eg, RV0) may be assumed.

The base station / terminal is a sMTC UE or an eMTC UE for two methods relating to a redundancy version (RV) value according to the repetition of the sMTC UE and a starting position in a circular buffer corresponding to the RV. Depending on whether the control region is used), or whether the sMTC UE supports data sharing between the sMTC UE and the eMTC UE (or refer to the corresponding signaling), depending on the redundancy version (RV) value according to repetition and the corresponding RV. It is possible to determine the starting position in the corresponding circular buffer.

The definition of EREG and ECCE of MPDCCH in eMTC is defined for symbol index l = 0 to 13 (in case of normal CP) in a subframe. However, the base station performs the actual MPDCCH transmission using only the REs belonging to the OFDM symbol after that including the starting symbol (startSymbolBR) (that is, satisfying the condition of l ≧ startSymbolBR). When the sMTC UE is configured to use the LTE control region, the base station may transmit MPDCCH even for OFDM symbol (s) before l = startSymbolBR. At this time, the following methods may be considered as the MPDCCH RE mapping method of the sMTC UE.

First, the base station may transmit the MPDCCH in the frequency-first-time-second manner from the first OFDM symbol capable of transmitting the MPDCCH by l = 0 or configured sMTC UE. This method may mean that when the MPDCCH transmission RE of the eMTC is determined, the base station replaces startSymbolBR with '0' or the configured sMTC UE with the first OFDM symbol value capable of MPDCCH transmission under the condition of l≥startSymbolBR. have. The above method has a simple advantage of RE mapping from the standpoint of supporting only the sMTC UE, but does not efficiently support MPDCCH data sharing with the eMTC UE as the RE mapping order is changed with the eMTC UE.

Second, the base station proceeds with RE mapping in the same manner as eMTC starting from l = startSymbolBR, and then the first OFDM symbol capable of transmitting MPDCCH by the sMTC UE having l = 0 or configured for RE added by using LTE control region. RE mapping may be performed in a frequency-first-time-second manner. The above method has the advantage of enabling efficient MPDCCH data sharing because OFDM symbols satisfying l ≧ startSymbolBR have the same understanding of RE mapping positions and order of sMTC and eMTC. This method may be useful when the base station transmits a control signal applied to both the existing eMTC and sMTC (or applied regardless of the eMTC and sMTC). At this time, the MPDCCH transmission REs that are available only to the sMTC UE (s) by the base station may be used for redundancy transmission or additional control data transmission only for the additional sMTC UE (s). The base station may copy and transmit some of OFDM symbols (or REs) belonging to OFDM symbols satisfying l ≧ startSymbolBR.

The above methods may be determined according to the type of control data or the search space (SS) type transmitted through the MPDCCH. For example, when control data transmitted through MPDCCH is transmitted through UE-specific or UE-specific search space (UESS), sMTC may apply the first method as it may not be necessary to consider data sharing with eMTC. Can be. Or, if control data transmitted through the MPDCCH is common to the sMTC UE (s) and eMTC UE (s), or transmitted through a common search space (CSS), the second method has an advantage in terms of data sharing with the eMTC Can be determined for use.

In the conventional eMTC, in the case of MPDCCH transmission, if the code rate of control data is more than a certain value (eg, code rate> ~ 0.8), it is difficult to receive from the terminal side, so that the size of a specific DCI format is assumed or overall. In consideration of the size of the DCI format, when the number of MPDCCH transmission REs (nRE, eMTC) of the eMTC is smaller than a specific value, the ECDC aggregation level (AL) is doubled, that is, the MPDCCH format in which the ECCE AL is doubled is selected. For example, if the code rate is less than nRE, eMTC = 104 corresponding to about 0.8, the ECCE AL is increased. However, in the case of sMTC UE, RE (nRE, sMTC) which can be used for MPDCCH transmission in the same subframe or slot is larger than or equal to eMTC. In other words, nRE, sMTC> = nRE, eMTC is established. At this time, ECCE AL determination for the sMTC UE can be determined in the following way.

First, the base station determines the ECCE AL of the sMTC based on the number of MPDCCH transmission REs (nRE, eMTC) of the eMTC. For example, if nRE, eMTC <104, the base station increases the ECCE AL of the sMTC. Since the relationship of nRE, sMTC> = nRE, eMTC is always established with respect to the number of MPDCCH transmission REs, in certain cases, for example, nRE, eMTC <104 <= nRE, sMTC, ECCE from the sMTC UE perspective. Although it is not necessary to increase the AL, in the above method, both the sMTC UE and the eMTC UE determine the ECCE AL based on nRE and eMTC, and the nRE, sMTC-nRE, eMTC REs are determined as sMTC UE in the determined ECCE AL. The performance improvement of MPDCCH for (s) or the use of additional control data for transmission is advantageous in terms of performance compared to the second method. In this method, nRE and eMTC, which are the criteria for ECCE AL determination, satisfy the condition l ≥ startSymbolBR even if the MPDCCH for the actual eMTC UE is not the transmission RE, for example, the MPDCCH transmission RE for the sMTC UE, that is, the LTE control region. Except for, it may mean the number of MPDCCH transmission REs.

Second, the base station determines the ECCE AL of the sMTC based on the number of MPDCCH transmission REs (nRE, sMTC) of the sMTC. For example, if nRE, sMTC <104, increase ECCE AL of sMTC. In the case of the present method, under certain conditions, the sMTC may have an ECCE AL different from the eMTC. For example, if nRE, eMTC <104 <= nRE, sMTC, in case of eMTC, the base station doubles the ECCE AL according to the condition nRE, eMTC <104, and in case of sMTC, 104 <= nRE, sMTC The ECCE AL may not be doubled. In this case, in consideration of the fact that the sMTC is inferior to the eMTC control data, the eNB determines that the above conditions occur, that is, when nRE, eMTC <104 <= nRE, sMTC. The base station may double the ECCE AL for the sMTC UE.

The two methods for determining the sMTC ECCE AL may be differently applied depending on whether the terminal is configured with one of two methods through higher layer signaling or whether (s) C sharing of the sMTC and the eMTC is performed. For example, when the sMTC and the eMTC share (control) data, the first method among the above methods, or when not sharing the (control) data, the terminal may select the first method among the above methods. . The control data sharing between the sMTC and the eMTC may be higher layer configure or may be dynamically indicated through DCI.

The sMTC UE may include the meaning of an LTE MTC UE capable of using an LTE control region. In this case, the first method described above also includes a number of MPDCCH transmission REs, like the legacy LTE MTC UE, using the LTE control region. It may be a method of determining AL (based on R2) only with REs belonging to the R2 region defined in the following. The second method may be a method of determining an AL (based on R1 + R2) for the UE using the LTE control region, including the REs belonging to the R1 region as well as the R2 region. The LTE MTC UE that can use the LTE control region supports only the second method, which is an R1 + R2 based AL decision method or an R1 + R2 based AL, in order to obtain an effect of additional control data transmission within the same max code rate limit. The second method, which is the decision method, can be used as the basic operation, and the first method, which is an R2-based AL decision method, can be applied under certain conditions. A specific condition for applying the first method may be, for example, a case in which the MPDCCH search space is shared with a conventional LTE MTC UE that does not use the LTE control region. That is, the UE may apply the first method to the MPDCCH transmitted through the Type1- / 1A- / 2- / 2A-MPDCCH CSS. In case of Type0-MPDCCH CSS, since it is UE-specifically configured like UESS and shares the search space with UESS, LTE MTC UE that can use LTE control area is not able to use LTE control area. You may not need to consider sharing your search space. Therefore, in this case, the UE may determine the AL by applying the UESS same method, that is, a second method of R1 + R2 based AL determination method for the LTE MTC UE that can use the LTE control region.

In the sMTC ECCE AL determination method, when retuning frequency (or NB), the first subframe or slot of the destination frequency (or NB) can be used as the guard period (GP), so that other subframes or slots of the same frequency (or NB) can be used. And other methods may be applied. If all or part of the LTE control region is used as a GP, the DL reception of the UE cannot be expected during the GP and therefore the eNB is not expected to perform DL scheduling during that interval, so in this case the sMTC ECCE AL decision is higher It may operate differently from layer signaling or dynamic signaling. For example, the base station / terminal is calculated from OFDM symbols excluding the GP interval (eg, the first one or two OFDM symbols) regardless of the signaled method, the first subframe or slot of the destination frequency (or NB). The MPDCCH transmission may be determined based on the RE or the sMTC ECCE AL determination method (first method) based on the nRE and eMTC may be used.

When the MPDCCH is repeatedly transmitted by applying frequency (NB) hopping to an LTE MTC UE that can use the LTE control region, the base station applies the same AL determination method to all subframes in the same NB and can use the LTE control region. The LTE MTC UE may not receive the MPDCCH during the guard period (GP). In this case, the terminal may apply the same AL determination method to the same NB and perform an average operation to obtain a repetition gain in the same NB except for a part of the MPDCCH which has not been received during the GP. Alternatively, the base station may perform an average operation to obtain a repetition gain using only the R2 region. Alternatively, in order to reduce the complexity of the receiver operation, when the base station transmits the MPDCCH through frequency (NB) hopping, the base station may transmit the MPDCCH by applying the first AL determination method (using only the R2 region). In this case, the UE capable of using the LTE control region receives MPDCCH by assuming the first AL determination method when the frequency (NB) hopping is on with reference to a higher layer configured frequency (NB) hopping on / off flag. And a BD operation for reception. The base station, if the frequency (NB) hopping is on, when the hopping interval (number of consecutive subframes used for MPDCCH transmission in the same NB between frequency hopping) is 1 or less than a specific value such as 2, in the R1 interval R1 + R2 based AL determination and RE mapping may be performed except for the OFDM symbol required for frequency retuning of the terminal.

3. Third Embodiment: Method of Using LTE Control Region for Control Signal Transmission

The LTE control region may be used for control signal transmission for the sMTC UE. As listed in the subclause of this section, the control signal for the sMTC UE may be a mode indication indicating whether to inform the sMTC support of the cell, control region indication information for the sMTC UE, and the like.

(1) Embodiment 3-1: Mode indication for sMTC devices

The mode indication method may be mode indication information that can only be understood by the sMTC in the case of PBCH. For example, the base station is an indication indicating whether the cell supports sMTC, or when operating in-band or standalone, whether the corresponding frequency band (including eMTC or sMTC) is LTE band, NR band, GSM band It can indicate whether it is a real standalone situation that does not belong to any band. For example, indication information on whether the cell supports sMTC is helpful in terms of sMTC device power saving. In addition, the information on the RAT of the corresponding or neighboring band may be used for measurement, in-band operation, and the like. Alternatively, when the indication indicates that the cell supports only sMTC, there is an advantage in that the MIB field in the PBCH can be reconfigured or optimized. For example, the base station can improve the reception performance by removing information such as unnecessary phich-config from the current eMTC and using it for other purposes or by removing unnecessary fields. As the signaling method, the following method can be considered.

How to use the Known Sequence

The above method may be signaling by sequence detection (or selection), that is, a signaling method of a base station through hypothesis testing. For example, it may be a method of transmitting 2 bits through four hypothesis testing after designating four sequences in advance.

Alternatively, the method may be a signaling method through a sequence initialization value of a base station. For example, the base station uses the gold sequence and uses signaling information to be transmitted for gold sequence initialization, and the receiver may receive signaling information used for initialization by performing sequence detection on the corresponding gold sequence.

Repeat legacy sync signals (PSS / SSS) with some potential modifications

The base station may use LTE PSS and / or SSS as it is, but may use a form distinguished from the existing LTE FDD / TDD pattern. Alternatively, the base station removes the possibility of detecting the legacy eMTC device false by copying the PSS and / or SSS in a time or frequency reversed form, and the sMTC can receive a corresponding control signal by detecting a pattern between time reversed PSS / SSS. have.

Repeat PBCH signals with some potential modifications

The base station may indicate the standalone mode by repeating the PBCH in a specific pattern. The PBCH repetition unit may be the entire PBCH (comprised of 4 OFDM symbols) or may be part of a PBCH (ie, some of the four OFDM symbols that make up the PBCH). For example, when the base station forms a pattern by copying a part of the PBCH to the LTE control region, the base station may copy the different parts of the PBCH to distinguish the pattern. Alternatively, the base station may transmit as much information as the corresponding state by configuring as many patterns as the number of cases in which three of the four OFDM symbols constituting the PBCH are arranged in order. Alternatively, the base station may distinguish patterns by multiplying orthogonal sequences by the same OFDM symbol.

Information transmission in coded bits with separate channel coding

This method is a method for transmitting additional information not included in MIB and / or SIB1-BR to the LTE control region by applying separate coding. For example, in the case of 1.4 MHz BW, only 4 SIB1-BR repetition can be supported, and can be used to convey information for notifying an additional repetition (if there is additional NB) to the sMTC UE. Or, eMTC terminal X (X is required to be indicated by one of the existing LTE system bandwidth that can be interpreted by the eMTC or LTE terminal, for example, if 1.4MHz is indicated, eMTC and LTE terminal is the corresponding cell eMTC If you want to set the additional BW to sMTC, the MIB indicates only X-MHz, and in the control area before the MIB (to extend the system bandwidth of sMTC). It can be used to further inform sMTC BW. In this case, initial access BW is X-MHz (CRS needs to be transmitted in RBs supported by at least X-MHz LTE system bandwidth), and CRS is present in BW that only sees sMTC indicated through LTE control region signaling. May be omitted. In this case, the sMTC may view the extended BW as the entire system BW and may also expect additional repetition of SIB1-BR according to the LTE control region signaling. However, rate-matching (for coherent combining with NB where CRS exists) can follow initial access BW as CRS exists. This extended BW need not be symmetrical with respect to the initial access BW, and there is no need to add RB gaps between the NBs. That is, the X-MHz indicated in the MIB can be used as a time / frequency resource used for coexistence with LTE and eMTC terminals, and the bandwidth allocated additionally to sMTC can be used to extend the bandwidth of sMTC while minimizing coexistence considerations. have. The method can be used to transmit information necessary for coexistence with NR. The system bandwidth extension information for the sMTC of the above purpose may be indicated using spare / reserved bits (bits not understood by the eMTC terminal) of the MIB, rather than the method indicated in the control region proposed above.

The sMTC UE performs a PBCH extension of the LTE control region (which may be filled with other information that is separately coded instead of PBCH repetition) before or simultaneously with PBCH decoding, or in consideration of the terminal complexity, decodes the PBCH in the same manner as the eMTC. Thereafter, the PBCH extension may be received after checking whether or not the PBCH extension is supported or not through a predefined MIB field (eg, MIB 1 spare bit).

(2) Embodiment 3-2: LTE control region indication

In the sMTC, the base station / terminal can more dynamically configure the MPDCCH / PDSCH region (that is, the start point of the OFDM symbol or the number of OFDM symbols used for MPDCCH / PDSCH transmission) or the LTE control region. As a method of utilizing this, for example, when the base station / terminal shares the eMTC and R2, the startSymbolBR of the SIB1-BR is set to the maximum value, and the sMTC UE is provided through the above dynamic control region indication method that only the sMTC UEs can receive. The control area for can be dynamically set or changed. In this manner, the sMTC UE may use a part of the LTE control region or all except the RE required for signaling and / or RS transmission through the dynamic configuration for the sMTC UE.

The LTE control region information may be repeated, for example, using the PCFICH of LTE as it is or in the frequency domain or in the OFDM symbol unit in the LTE control region (ie, according to CE mode / level) for coverage extension (ie, according to CE mode / level). Or it may be repeated over the LTE control region of a plurality of subframes.

In relation to the above, the LTE control region information for the conventional eMTC is transmitted in the broadcast form (e.g., SIB) or specified in the spec as a fixed value if inevitable. At this time, the starting symbol value (startSymbolBR) of the MPDCCH / PDSCH allowed to the eMTC is 1/2/3/4, but the starting symbol value of the MPDCCH / PDSCH allowed to the sMTC may include 0 (eg, startSymbolBR = 0/1/2/3/4). The base station may indicate to the eMTC UE and the sMTC UE in the SIB as follows. For example, the base station informs the sMTC UE of one of startSymbolBR = 0/1/2/3/4 in a separate SIB field (a separate startSymbolBR maximum value that only the sMTC terminal can understand is indicated by the startSymbolBR indicated to the eMTC). It may be set to be smaller), the sMTC UE can always be recognized as startSymbolBR = 0 regardless of the SIB, or whether or not startSymbolBR = 0 may be informed to the UE-specific RRC.

(3) Embodiment 3-3: 3.3.3 UL HARQ-ACK feedback signaling

In the conventional eMTC, only asynchronous HARQ is supported for UL transmission. In sMTC, the base station may support synchronous HARQ for UL transmission by transmitting an HARQ-ACK feedback signal in the LTE control region. Here, the definition of synchronous may be more extensive than synchronous HARQ in LTE. For example, a UL HARQ-ACK feedback time point after a UL transmission has a specific period (eg, configured by higher layer or by UL scheduling DCI). The first UL HARQ-ACK feedback transmission opportunity can be defined as an opportunity type, starting at a point in time (eg, configured by higher layer or by UL scheduling DCI) from the last or first subframe criterion of the (repeated) UL transmission. (synchronous) Can be repeated with a certain period.

Through the UL HARQ-ACK feedback signal, the eNB may perform an early UL HARQ-ACK feedback signal when the sMTC succeeds in 'early' decoding at the time when the sMTC does not repeat the UL data repeatedly transmitted by the UE. . The sMTC UE may reduce power consumption by early stopping UL transmission by using an early UL HARQ-ACK feedback signal. The sMTC UE may need to monitor the UL HARQ-ACK feedback signal in the above-mentioned periodic UL HARQ-ACK feedback signal transmission opportunity during UL repeated transmission to determine the UL transmission termination time.

(4) Embodiment 3-4: DL control search space (SS) for sMTC UE

The base station may configure a new DL control SS in the LTE control region and use it for sMTC DL control channel transmission. For example, the base station may configure a USS for the sMTC UE in the LTE control region, and the USS may be allowed only to the sMTC UE or limited to only UEs configured to use the LTE control region. Alternatively, the base station may use the USS to support self-subframe scheduling to the high capability UE. Alternatively, the base station may configure CSS for the sMTC UE, and perform CSS monitoring at R1 and USS monitoring (LTE EPDCCH operation) at R2.

The base station may define a new ECCE in the LTE control region to transmit a control channel for the sMTC UE in the LTE control region. As for the sMTC UE, the base station may configure the AL by combining the ECCE defined in the LTE control region and the ECCE of the conventional MPDCCH region. Alternatively, the base station may follow the CCE configuration of the LTE CCE of the LTE control region.

In the method of lowering the code rate of the MPDCCH / PDSCH data, a method of copying a part of the MPDCCH OFDM symbol to the LTE control region has been proposed to improve the performance of the MPDCCH. In this case, the common search space (CSS) is common to the eMTC. In case of reception, the base station may assume that there is a CRS and extend the MPDCCH. In the US-specific search space (USS), in case of a control channel for an sMTC UE, the base station may differently select whether to view the CRS according to the BL / CE DL subframe and the MBSFN subframe configuration. Even in the case of extending the assumption that there is no CRS, when the repetitive transmission is set and the section to which the CRS should be transmitted is included in the repetitive transmission section, the base station may assume that the CRS is present.

(5) Embodiment 3-5: time resource for coexistence with another system

All the above proposals utilize a LTE control region to transmit a specific signal or channel, but do not transmit a signal for sMTC for coexistence with another system (eg, a service requiring NR or low latency). There may also be a method of emptying. This is possible in the case of not supporting eMTC or LTE, and sMTC terminals may be configured to expect a signal / channel in the LTE control region periodically or aperiodically in a specific subframe. That is, when coexistence with a third system is required, the LTE control region can be used for sMTC terminals in an opportunistic manner, and this is whether the sMTC terminal can expect a signal / channel for each subframe in the form of signaling (eg, bitmap). It can be implemented by setting the method.

4. Fourth Embodiment: sMTC system operation

This section proposes actions, controls, etc. to be considered for sMTC system support.

(1) Embodiment 4-1: Use of LTE Control Region

The LTE control region is not used in the idle mode channel or signal, but may be used only in the connected mode. For example, the base station may use the LTE control region only when the UE specific RRC is instructed to use the LTE control region in the connected mode. The LTE control region usage indication may be in the form of a subframe bitmap for a subframe that can use a kind of LTE control region. Alternatively, whether to use the LTE control region may be set for each frequency. For example, the sMTC operates over the NR frequency region and the LTE frequency region, or over the RAT region or the empty spectrum, which is different from the NR frequency region where the first few OFDM symbol (s) of a subframe or slot are used for specific purposes such as control. Alternatively, when the first few OFDM symbol (s) of a specific bandwidth part or a subframe or slot of some frequency region in NR are used for a specific purpose such as control, the use of the LTE control region may be set for each frequency.

Alternatively, the base station may apply the LTE control channel only when the data channel is scheduled. For example, the base station may not use the LTE control region in the MPDCCH transmission subframe but may use the LTE control region only in the PDSCH transmission subframe. In the PDSCH transmission subframe, the base station may dynamically indicate whether to use the LTE control region and related detailed parameters (e.g., RE mapping method, channel coding related option, etc.) in the scheduling DCI.

In addition, related options including whether to use the LTE control region may be configured to be cell-specific and / or UE-specific higher layer.

(2) Embodiment 4-2: GP (guard period) for NB retuning when using LTE control region

In eMTC, in case of Tx-to-Rx or Rx-to-Rx NB retuning, the DL subframe on the Rx side always absorbs the switching gap. The reason is that in case of BL / CE subframe, in order to protect the LTE control region, DL transmission is not performed to the eMTC UE for the first L symbol (L is fixed to 3 or 4 or higher layer configured at a value in the range of 1-4). Because. However, in sMTC, since the base station does not need to protect the LTE control region, the LTE control region may be used for DL data or DL control signaling as proposed by the present invention. Therefore, it is necessary to consider the GP for Tx-to-Rx or Rx-to-Rx NB retuning.

The base station is configured for the sMTC UE or when the sMTC UE is configured to receive DL data or control signals (eg, (M) PDCCH) through the LTE control region, according to the data type or the priority of the data type. The location of the GP may be determined as a source NB or a destination NB. The data type may be classified into payload data and a control signal downloaded from an upper layer. For example, the control signal has a higher priority than data. Thus, for example, in A-to-B NB retuning, whether GP is set to A or B is a control signal and if B is data (transmitted by PDSCH), then GP is the first of B (i.e. destination NB). If set to OFDM symbol (s) and vice versa is set to the last OFDM symbol (s) of A (i.e. source NB), if equal priority, i.e. both data or all control signals, GP is in OFDM units for A and B. Divided into evenly. As an example of the equal division method, when the GP length corresponds to two OFDM symbols, one OFDM symbol is arranged in each of A and B to form a GP. Alternatively, if even division is not possible because the length of the GP is odd in units of OFDM symbols, GP is always set so that the A side, that is, the source NB side is one more OFDM units than the destination NB. If both control signal monitoring and data reception are attempted in a specific subframe, the subframe can be regarded as a subframe for monitoring the control signal and a GP can be created. In this case, the GP section is a section in which the base station does not perform MPDCCH / PDSCH scheduling or does not actually transmit a signal to the section, but considers the section as a GP according to the capability of the terminal and does not attempt to receive the section. Can be. In the case of Tx-to-Rx, if the last symbol in the subframe immediately before Rx is set as an interval for SRS transmission, the terminal regards the interval as part of the GP, and the first partial time of the Rx interval after Tx ( Only the GP request time-SRS transmission interval) can be used as the interval for the remaining GP. Here, when the SRS transmission is not set for the terminal expecting Rx or the terminal does not transmit the actual SRS and other UL signals in the set SRS interval, the SRS interval is regarded as a partial interval of the GP, as proposed above. can do. Alternatively, a new signal or message may be defined for the purpose of generating such a GP, and the base station may inform the terminal of this.

Alternatively, there is a method in which the base station directly indicates a section that can be used as a GP in the Rx section. Unlike the above proposal, since the signal transmitted by the base station in the Rx interval can be resource mapping in a rate-matching manner, there may be a gain in terms of code rate. To this end, the terminal may separately report the required GP section. However, when receiving a channel (for example, paging, common DCI, etc.) that can be expected to be received at the same time with eMTC terminals or other sMTC terminals, it is generated based on the GP (which may be determined as a control region value) of the eMTC. Only GPs can assume terminals.

The proposed methods can be applied / analyzed differently in RRC connected mode and idle mode.

The LTE control region may be used as a GP for frequency (or narrowband) retuning. In this case, like the eMTC, the UE may not perform DL reception during the LTE control region, and the eNB may secure the GP by not performing MPDCCH / PDSCH scheduling during the corresponding interval. The enable / disable signal for using the LTE control region as a GP may be UE-specifically configured through higher layer signaling or dynamically configured through DCI, and may be automatically used as a GP in a specific subframe or slot. The specific subframe or slot may be the first subframe or slot of the destination frequency (or narrowband) in the above description. When applied as the method of using the LTE control region (proposed in 3.1, 3.2, 3.3), it is used as a GP only for the specific subframe or slot, and for the remaining subframes or slots, the above-described 3.1, 3.2, 3.3 The method of utilizing the LTE control region (higher layer configured) proposed in the section may be applied. In order to support the LTE control region utilization method more dynamically, the base station can use the LTE control region utilization method of the corresponding subframe or slot through scheduling DCI (eg, whether it is used as one of the methods proposed in Sections 3.1, 3.2, and 3.3 above). Can be used as a GP).

The number of OFDM symbols that an sMTC can expect to receive in the LTE control region may vary depending on the UE. For example, the number of usable LTE control regions may vary according to the frequency retuning time of the UL. In this case, all of the above may be applied to each UE as well. On the other hand, since the first symbol in which the CRS is transmitted is advantageous in terms of reception performance, sMTC terminals expect DL transmission for all OFDM symbols in the LTE control region, and the eNB can schedule the MPDCCH / PDSCH during the interval. . At this time, the necessary retuning gap is secured to the last OFDM symbol (s) of the previous subframe or slot. In this case, the eNB performs rate-matching assuming GP for the last OFDM symbol (s) of the subframe or slot. The sMTC terminal may assume rate-matching with respect to the GP.

5. Embodiment 5: Support Method

This section proposes a method for supporting sMTC system in TDD.

(1) Embodiment 5-1: Mode indication for sMTC devices

Even in CE mode B, the sMTC terminal can expect to receive MPDCCH in DwPTS, and the required number of OFDM symbols is a special subframe secured by the number of OFDM symbols that can be secured in DwPTS when CE mode A excludes the control region in the existing eMTC. It may be limited to a configuration.

In the case of the CE mode A, as described above, when the number of OFDM symbols including all the symbols of the control region is secured by the number of symbols required for the eMTC to utilize the DwPTS, MPDCCH reception can be expected in the corresponding DwPTS.

Even in CE mode B, the sMTC terminal can expect PDSCH reception in DwPTS, and the required number of OFDM symbols is a special subframe secured by the number of OFDM symbols that can be secured in DwPTS when CE mode A is excluded from the control region in the existing eMTC. It may be limited to a configuration.

In the case of the CE mode A, as described above, when the number of OFDM symbols including all the symbols of the control region is secured by the number of symbols required for the eMTC to utilize the DwPTS, PDSCH reception can be expected in the corresponding DwPTS.

When the A / B / C / D is shared with the eMTC, the use of the DwPTS is interpreted in the same manner as the eMTC.

<본 발명이 적용되는 통신 시스템 예><Communication system example to which the present invention is applied>

Referring to FIG. 30, a wireless communication system may include a first device 3010 and a second device 3020.

The first device 3010 includes a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV, artificial intelligence module, robot, augmented reality device, virtual reality device, mixed reality device, hologram device, public safety device, MTC device, IoT device, medical device, pin It may be a tech device (or financial device), a security device, a climate / environment device, a device related to 5G service, or another device related to the fourth industrial revolution field.

The second device 3020 includes a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV, artificial intelligence module, robot, augmented reality device, virtual reality device, mixed reality device, hologram device, public safety device, MTC device, IoT device, medical device, pin It may be a tech device (or financial device), a security device, a climate / environment device, a device related to 5G service, or another device related to the fourth industrial revolution field.

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, the HMD may be a display device worn on the head. For example, the HMD can be used to implement VR, AR or MR.

For example, a drone may be a vehicle in which humans fly by radio control signals. For example, the VR device may include a device that implements an object or a background of a virtual world. For example, the AR device may include a device that connects and implements an object or a background of the virtual world to an object or a background of the real world. For example, the MR device may include a device that fuses and implements an object or a background of the virtual world to an object or a background of the real world. For example, the hologram device may include a device that records and reproduces stereoscopic information to realize a 360 degree stereoscopic image by utilizing interference of light generated by two laser lights, called holography, to meet each other. For example, the public safety device may include an image relay device or an image device wearable on a human body of a user. For example, the MTC device and the IoT device may be devices that do not require direct human intervention or manipulation. For example, the MTC device and the IoT device may include a smart meter, a bending machine, a thermometer, a smart bulb, a door lock or various sensors. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, treating or preventing a disease. For example, a medical device may be a device used for the purpose of diagnosing, treating, alleviating or correcting an injury or disorder. For example, a medical device may be a device used for the purpose of inspecting, replacing, or modifying a structure or function. For example, the medical device may be a device used for controlling pregnancy. For example, the medical device may include a medical device, a surgical device, an (in vitro) diagnostic device, a hearing aid or a surgical device, and the like. For example, the security device may be a device installed to prevent a risk that may occur and to maintain safety. For example, the security device may be a camera, a CCTV, a recorder or a black box. For example, the fintech device may be a device capable of providing financial services such as mobile payment. For example, the fintech device may include a payment device or a point of sales (POS). For example, the climate / environmental device may include a device for monitoring or predicting the climate / environment.

The first device 3010 may include at least one or more processors, such as a processor 3011, at least one or more memories, such as a memory 3012, and at least one or more transceivers, such as a transceiver 3013. The processor 3011 may perform the functions, procedures, and / or methods described above. The processor 3011 may perform one or more protocols. For example, the processor 3011 may perform one or more layers of a radio interface protocol. The memory 3012 is connected to the processor 3011 and may store various types of information and / or instructions. The transceiver 3013 may be connected to the processor 3011 and controlled to transmit and receive a wireless signal.

The second device 3020 may include at least one processor, such as a processor 3021, at least one or more memory devices, such as a memory 3022, and at least one transceiver, such as a transceiver 3023. The processor 3021 may perform the functions, procedures, and / or methods described above. The processor 3021 may implement one or more protocols. For example, the processor 3021 may implement one or more layers of a radio interface protocol. The memory 3022 may be connected to the processor 3021 and store various types of information and / or instructions. The transceiver 3023 is connected to the processor 3021 and may be controlled to transmit and receive a wireless signal.

The memory 3012 and / or the memory 3022 may be respectively connected inside or outside the processor 3011 and / or the processor 3021, and may be connected to other processors through various technologies such as wired or wireless connection. It may also be connected to.

The first device 3010 and / or the second device 3020 may have one or more antennas. For example, antenna 3014 and / or antenna 3024 may be configured to transmit and receive wireless signals.

Referring to FIG. 31, a wireless communication system includes a base station 3110 and a plurality of terminals 3120 located in a base station area. The base station may be represented by a transmitting device, the terminal may be represented by a receiving device, and vice versa. The base station and the terminal are a processor (processor, 3111, 3121), memory (memory, 3114, 3124), one or more Tx / Rx RF module (radio frequency module, 3115, 3125), Tx processor (3112, 3130), Rx processor ( 3113 and 3123, and

antennas

3116 and 3126. The processor implements the salping functions, processes and / or methods above. More specifically, in the DL (communication from the base station to the terminal), upper layer packets from the core network are provided to the processor 3111. The processor implements the functionality of the L2 layer. In the DL, the processor provides the terminal 3120 with multiplexing and radio resource allocation between the logical channel and the transport channel and is responsible for signaling to the terminal. The transmit (TX) processor 3112 implements various signal processing functions for the L1 layer (ie, the physical layer). The signal processing function facilitates forward error correction (FEC) in the terminal and includes coding and interleaving. The encoded and modulated symbols are divided into parallel streams, each stream mapped to an OFDM subcarrier, multiplexed with a reference signal (RS) in the time and / or frequency domain, and using an Inverse Fast Fourier Transform (IFFT). To be combined together to create a physical channel carrying a time-domain OFDMA symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Each spatial stream may be provided to a different antenna 3116 via a separate Tx / Rx module (or transceiver 3115). Each Tx / Rx module can modulate an RF carrier with each spatial stream for transmission. At the terminal, each Tx / Rx module (or transceiver 3125) receives a signal through each antenna 3126 of each Tx / Rx module. Each Tx / Rx module recovers information modulated onto an RF carrier and provides it to a receive (RX) processor 3122. The RX processor implements the various signal processing functions of layer 1. The RX processor may perform spatial processing on the information to recover any spatial stream destined for the terminal. If multiple spatial streams are directed to the terminal, it may be combined into a single OFDMA symbol stream by multiple RX processors. The RX processor uses fast Fourier transform (FFT) to convert the OFDMA symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDMA symbol stream for each subcarrier of the OFDM signal. The symbols and reference signal on each subcarrier are recovered and demodulated by determining the most likely signal placement points sent by the base station. Such soft decisions may be based on channel estimate values. Soft decisions are decoded and deinterleaved to recover the data and control signals originally sent by the base station on the physical channel. The data and control signals are provided to the processor 3121.

UL (communication from terminal to base station) is processed at base station 3110 in a manner similar to that described with respect to receiver functionality at terminal 3120. Each Tx / Rx module 3125 receives a signal through each antenna 3126. Each Tx / Rx module provides an RF carrier and information to the RX processor 3123. The processor 3121 may be associated with a memory 3124 that stores program code and data. The memory may be referred to as a computer readable medium.

The wireless device may be implemented in various forms depending on the use-example / service.

Referring to FIG. 32, the

wireless devices

100 and 200 correspond to the

wireless devices

3010 and 3020 of FIG. 30, and various elements, components, units / units, and / or modules are described. It can be configured as a module. For example, the

wireless device

100, 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional elements 140. The communication unit may include communication circuitry 112 and transceiver (s) 114. For example, the communication circuit 112 may include one or

more processors

3012, 3022 and / or one or

more memories

3014, 3024 of FIG. 30. For example, the transceiver (s) 114 may include one or more transceivers 3016, 3026 and / or one or more antennas 3018, 3028 of FIG. 30. The controller 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional element 140, and controls various operations of the wireless device. For example, the controller 120 may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit 130. In addition, the control unit 120 transmits the information stored in the memory unit 130 to the outside (eg, other communication devices) through the communication unit 110 through a wireless / wired interface, or externally (eg, through the communication unit 110). Information received through a wireless / wired interface from another communication device) may be stored in the memory unit 130.

The additional element 140 may be configured in various ways depending on the type of wireless device. For example, the additional element 140 may include at least one of a power unit / battery, an I / O unit, a driver, and a computing unit. Although not limited to this, the wireless device may be a robot (FIGS. W1, 100a), a vehicle (FIGS. W1, 100b-1, 100b-2), an XR device (FIGS. W1, 100c), a portable device (FIGS. W1, 100d), a home appliance (Fig. W1, 100e), IoT devices (Fig. W1, 100f), terminals for digital broadcasting, hologram devices, public safety devices, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate / environment devices, It may be implemented in the form of an AI server / device (FIG. W1, 400), a base station (FIG. W1, 200), a network node, or the like. The wireless device may be used in a mobile or fixed location depending on the usage-example / service.

In FIG. 32, various elements, components, units / units, and / or modules in the

wireless devices

100 and 200 may be entirely interconnected through a wired interface, or at least a part thereof may be wirelessly connected through the communication unit 110. For example, the control unit 120 and the communication unit 110 are connected by wire in the

wireless device

100 or 200, and the control unit 120 and the first unit (eg, 130 and 140) are connected through the communication unit 110. It can be connected wirelessly. In addition, each element, component, unit / unit, and / or module in

wireless device

100, 200 may further include one or more elements. For example, the controller 120 may be composed of one or more processor sets. For example, the controller 120 may be configured as a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, and the like. As another example, the memory unit 130 may include random access memory (RAM), dynamic RAM (DRAM), read only memory (ROM), flash memory, volatile memory, and non-volatile memory. volatile memory) and / or combinations thereof.

Hereinafter, the implementation example of FIG. 24 will be described in more detail with reference to the accompanying drawings.

33 illustrates a signal processing circuit for a transmission signal.

Referring to FIG. 33, the signal processing circuit 1000 may include a scrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040, a resource mapper 1050, and a signal generator 1060. have. Although not limited thereto, the operations / functions of FIG. 25 may be performed by the

processors

3012 and 3022 and / or the transceivers 3016 and 3026 of FIG. 30. The hardware elements of FIG. 25 may be implemented in the

processors

3012 and 3022 and / or transceivers 3016 and 3026 of FIG. 30. For example, blocks 1010-1060 may be implemented in the

processors

3012, 3022 of FIG. 30. Also, blocks 1010 to 1050 may be implemented in the

processors

3012 and 3022 of FIG. 30, and block 1060 may be implemented in the transceivers 3016 and 3026 of FIG. 30.

The codeword may be converted into a wireless signal through the signal processing circuit 1000 of FIG. 33. Here, the codeword is an encoded bit sequence of the information block. The information block may include a transport block (eg, a UL-SCH transport block and a DL-SCH transport block). The wireless signal may be transmitted through various physical channels (eg, PUSCH, PDSCH).

In detail, the codeword may be converted into a scrambled bit sequence by the scrambler 1010. The scramble sequence used for scramble is generated based on the initialization value, and the initialization value may include ID information of the wireless device. The scrambled bit sequence may be modulated into a modulation symbol sequence by the modulator 1020. The modulation scheme may include pi / 2-Binary Phase Shift Keying (pi / 2-BPSK), m-Phase Shift Keying (m-PSK), m-Quadrature Amplitude Modulation (m-QAM), and the like. The complex modulation symbol sequence may be mapped to one or more transport layers by the layer mapper 1030. The modulation symbols of each transport layer may be mapped (precoded) by the precoder 1040 to the corresponding antenna port (s). The output z of the precoder 1040 may be obtained by multiplying the output y of the layer mapper 1030 by the precoding matrix W of N * M. Where N is the number of antenna ports and M is the number of transport layers. Here, the precoder 1040 may perform precoding after performing transform precoding (eg, DFT transform) on complex modulation symbols. Also, the precoder 1040 may perform precoding without performing transform precoding.

The resource mapper 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resource may include a plurality of symbols (eg, CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain, and may include a plurality of subcarriers in the frequency domain. The signal generator 1060 generates a radio signal from the mapped modulation symbols, and the generated radio signal may be transmitted to another device through each antenna. To this end, the signal generator 1060 may include an Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, and the like. .

The signal processing procedure for the received signal in the wireless device may be configured in the reverse of the signal processing procedures 1010 ˜ 1060 of FIG. 33. For example, the wireless device (eg, 100 and 200 of FIG. 30) may receive a wireless signal from the outside through an antenna port / transceiver. The received wireless signal may be converted into a baseband signal through a signal recoverer. To this end, the signal recoverer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP canceller, and a fast fourier transform (FFT) module. Thereafter, the baseband signal may be restored to a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scramble process. The codeword may be restored to the original information block through decoding. Thus, a signal processing circuit (not shown) for the received signal may include a signal recoverer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler and a decoder.

34 illustrates a portable device applied to the present invention. The mobile device may include a smart phone, a smart pad, a wearable device (eg, smart watch, smart glasses), a portable computer (eg, a notebook, etc.). The mobile device may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), or a wireless terminal (WT).

Referring to FIG. 34, the portable device 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a memory unit 130, a power supply unit 140a, an interface unit 140b, and an input / output unit 140c. ) May be included. The antenna unit 108 may be configured as part of the communication unit 110. Blocks 110 to 130 / 140a to 140c correspond to blocks 110 to 130/140 of FIG. 25, respectively.

The bride 110 may transmit and receive signals (eg, data, control signals, etc.) with other wireless devices and base stations. The controller 120 may control various components of the mobile device 100 to perform various operations. The control unit 120 may include an application processor (AP). The memory unit 130 may store data / parameters / programs / codes / commands necessary for driving the portable device 100. In addition, the memory unit 130 may store input / output data / information and the like. The power supply unit 140a supplies power to the portable device 100 and may include a wired / wireless charging circuit, a battery, and the like. The interface unit 140b may support the connection of the mobile device 100 to another external device. The interface unit 140b may include various ports (eg, audio input / output port and video input / output port) for connecting to an external device. The input / output unit 140c may receive or output image information / signal, audio information / signal, data, and / or information input from a user. The input / output unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker, and / or a haptic module.

For example, in the case of data communication, the input / output unit 140c obtains information / signals (eg, touch, text, voice, image, and video) input from the user, and the obtained information / signal is stored in the memory unit 130. Can be stored. The communication unit 110 may convert the information / signal stored in the memory into a wireless signal, and directly transmit the converted wireless signal to another wireless device or to the base station. In addition, the communication unit 110 may receive a radio signal from another wireless device or a base station, and then restore the received radio signal to original information / signal. The restored information / signal may be stored in the memory unit 130 and then output in various forms (eg, text, voice, image, video, heptic) through the input / output unit 140c.

35 illustrates an XR device to which the present invention is applied.

The XR device may be implemented as an HMD, a head-up display (HUD) provided in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, and the like.

Referring to FIG. 35, the XR device 100a may include a communication unit 110, a control unit 120, a memory unit 130, an input / output unit 140a, a sensor unit 140b, and a power supply unit 140c. . Here, blocks 110 to 130 / 140a to 140c correspond to blocks 110 to 130/140 of FIG. 25, respectively.

The communication unit 110 may transmit and receive signals (eg, media data, control signals, etc.) with other wireless devices, portable devices, or external devices such as a media server. The media data may include an image, an image, a sound, and the like. The controller 120 may control various components of the XR device 100a to perform various operations. For example, the controller 120 may be configured to control and / or perform a procedure such as video / image acquisition, (video / image) encoding, metadata generation and processing, and the like. The memory unit 130 may store data / parameters / programs / codes / commands necessary for driving the XR device 100a and generating an XR object. The input / output unit 140a may obtain control information, data, and the like from the outside, and output the generated XR object. The input / output unit 140a may include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptic module. The sensor unit 140b may obtain XR device status, surrounding environment information, user information, and the like. The sensor unit 140b may 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 / or a radar. have. The power supply unit 140c supplies power to the XR device 100a and may include a wired / wireless charging circuit and a battery.

For example, the memory unit 130 of the XR device 100a may include information (eg, data, etc.) necessary for generating an XR object (eg, an AR / VR / MR object). The input / output unit 140a may obtain a command for operating the XR device 100a from the user, and the control unit 120 may drive the XR device 100a according to a user's driving command. For example, when a user tries to watch a movie, news, or the like through the XR device 100a, the controller 120 transmits the content request information to another device (eg, the mobile device 100b) or the communication unit 130. Can send to media server. The communication unit 130 may download / stream content such as a movie or news from another device (eg, the mobile device 100b) or a media server to the memory unit 130. The controller 120 controls and / or performs video / image acquisition, (video / image) encoding, metadata generation / processing, etc. with respect to content, and is obtained through the input / output unit 140a / sensor 140b. An XR object may be generated / output based on information about one surrounding space or reality object.

In addition, the XR device 100a is wirelessly connected to the mobile device 100b through the communication unit 110, and the operation of the XR device 100a may be controlled by the mobile device 100b. For example, the mobile device 100b may operate as a controller for the XR device 100a. To this end, the XR device 100a may obtain three-dimensional position information of the mobile device 100b and then generate and output an XR object corresponding to the mobile device 100b.

36 is a flowchart illustrating a method of receiving an MPDCCH by a terminal.

First, the terminal may receive a control region set in the first resource element of the first slot from the base station (S3610).

Subsequently, the terminal may be allocated a cell specific reference signal (CRS) to the second resource element of the second slot after the first slot from the base station (S3620).

Next, the UE may transition (copy) the cell specific reference signal to the control region set in the first resource element of the first slot (S3630).

Finally, the terminal may receive the MPDCCH on the first slot and the second slot (S3640).

First, the base station may set a control region in the first resource element of the first slot (S3710).

Subsequently, the base station may allocate a cell specific reference signal (CRS) to the second resource element of the second slot after the first slot (S3730).

Finally, the base station may transmit the MPDCCH on the first slot and the second slot (S3750).

<본 명세서와 관련된 참고 사항><Notes related to this specification>

In the present specification, the wireless device includes a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, Robots, Augmented Reality (AR) devices, Virtual Reality (VR) devices, MTC devices, IoT devices, medical devices, fintech devices (or financial devices), security devices, climate / environmental devices, or other areas of the fourth industrial revolution, or Device associated with 5G service. For example, a drone may be a vehicle in which humans fly by radio control signals. For example, the MTC device and the IoT device are devices that do not require human intervention or manipulation, and may be smart meters, bending machines, thermometers, smart bulbs, door locks, various sensors, and the like. For example, a medical device is a device used for the purpose of examining, replacing, or modifying a device, structure, or function used for diagnosing, treating, alleviating, treating or preventing a disease. In vitro) diagnostic devices, hearing aids, surgical devices, and the like. For example, the security device is a device installed to prevent a risk that may occur and maintain safety, and may be a camera, a CCTV, a black box, or the like. For example, the fintech device is a device that can provide financial services such as mobile payment, and may be a payment device or a point of sales (POS). For example, the climate / environmental device may mean a device for monitoring and predicting the climate / environment.

Next, a number of use cases will be described in more detail.

In the present specification, a terminal is a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant, a portable multimedia player, a navigation, a slate PC, a tablet PC. (tablet PC), ultrabook, wearable device (e.g., smartwatch, glass glass, head mounted display), foldable device And the like. For example, the HMD is a display device of a head type, and may be used to implement VR or AR.

The embodiments described above are the components and features of the present invention are combined in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be embodied in a form that is not combined with other components or features. In addition, it is also possible to configure the embodiments of the present invention by combining some components and / or features. 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. It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation in the claims, or may be incorporated into new claims by post-application correction.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. For implementation in hardware, an embodiment 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), and FPGAs ( field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code may be stored in memory and driven by the processor. The memory may be located inside or outside the processor, and may exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential features of the present invention. Accordingly, the above detailed description should not be construed as limiting in all respects but 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.

Although the present invention has been described with reference to an example applied to 3GPP LTE / LTE-A / NR system, it is possible to apply to various wireless communication systems in addition to 3GPP LTE / LTE-A / NR system.

Claims

A method for transmitting a physical broadcast channel (PBCH) by a base station supporting machine type communication (MTC) in a wireless communication system,

Mapping a PBCH to a plurality of resource elements (REs); And

And transmitting the PBCH to the UE on the plurality of REs.

The PBCH mapping is

Copying PBCH Orthogonal Frequency Division Multiplexing (OFDM) symbols included in PBCH repetition to an LTE control region in consideration of a frame structure type;

Way.
The method of claim 1,

Characterized in that all or some of the PBCH OFDM symbols are copied to the LTE control region according to a PBCH repetition pattern determined according to the frame structure type.

Way.
The method of claim 2,

The PBCH OFDM symbols are characterized by consisting of four OFDM symbols,

Way.
The method of claim 1,

The PBCH repetition is performed in a first subframe and a second subframe.

Way.
The method of claim 4, wherein

When the frame structure type is frame structure type 1, the first subframe is subframe 0, the second subframe is subframe 9,

When the frame structure type is frame structure type 2, the first subframe is subframe 0, and the second subframe is subframe 5,

Way.
The method of claim 2,

If the frame structure type is frame structure type 1, all of the PBCH OFDM symbols are copied to the LTE control region,

When the frame structure type is frame structure type 2, a part of the PBCH OFDM symbols are copied to the LTE control region,

Way.
The method of claim 4, wherein

The PBCH OFDM symbols are copied to at least one of the LTE control region of the first sub-frame or the LTE control region of the second sub-frame,

Way.
The method of claim 1,

The PBCH OFDM symbols included in the repeated PBCH repetition after the LTE control region may be the same interval as the PBCH OFDM symbols copied to the LTE control region.

Way.
In the base station for supporting the machine type communication (MTC) in a wireless communication system and to transmit a physical broadcast channel (PBCH),

Communication unit for transmitting and receiving a wireless signal;

A processor; And

At least one computer memory operatively connectable to said processor, said at least one computer memory storing instructions for performing operations when executed by said at least one processor,

The operations are

Mapping a PBCH to a plurality of resource elements (REs); And

And transmitting the PBCH to the UE on the plurality of REs.

The PBCH mapping is

Copying PBCH Orthogonal Frequency Division Multiplexing (OFDM) symbols included in PBCH repetition to an LTE control region in consideration of a frame structure type;

Base station.
The method of claim 9,

All or part of the PBCH OFDM symbols are copied to the LTE control region according to a PBCH repetition pattern determined according to the frame structure type.

Base station.
The method of claim 10,

The PBCH OFDM symbols are characterized by consisting of four OFDM symbols,

Base station.
The method of claim 9,

The PBCH repetition is performed in a first subframe and a second subframe.

Base station.
The method of claim 12,

When the frame structure type is frame structure type 1, the first subframe is subframe 0, the second subframe is subframe 9,

When the frame structure type is frame structure type 2, the first subframe is subframe 0, the second subframe is subframe 5,

Base station.
The method of claim 10,

If the frame structure type is frame structure type 1, all of the PBCH OFDM symbols are copied to the LTE control region,

When the frame structure type is frame structure type 2, a part of the PBCH OFDM symbols are copied to the LTE control region,

Base station.
The method of claim 12,

The PBCH OFDM symbols are copied to at least one of the LTE control region of the first sub-frame or the LTE control region of the second sub-frame,

Base station.
The method of claim 9,

The PBCH OFDM symbols included in the repeated PBCH repetition after the LTE control region may be the same interval as the PBCH OFDM symbols copied to the LTE control region.

Base station.