WO2018012833A1

WO2018012833A1 - Method for effectively transmitting control message for random access

Info

Publication number: WO2018012833A1
Application number: PCT/KR2017/007367
Authority: WO
Inventors: 김요한; 김재원; 설대영
Original assignee: 삼성전자 주식회사
Priority date: 2016-07-11
Filing date: 2017-07-10
Publication date: 2018-01-18

Abstract

The present disclosure relates to a communication technique for convergence of a 5G communication system for supporting a higher data transmission rate beyond a 4G system with an IoT technology, and a system therefor. The present disclosure may be applied to an intelligent service (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety-related service, etc.) on the basis of a 5G communication technology and an IoT-related technology. The present invention relates to a method and device for effectively transmitting or receiving control information for random access in a communication system. According to various embodiments of the present invention, information related to initial random access can be effectively transmitted or received.

Description

Control Message Transmission Method for Effective Random Access

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for effectively transmitting and receiving control information for random access in a communication system.

In order to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems, efforts are being made to develop improved 5G communication systems or pre-5G communication systems. For this reason, a 5G communication system or a pre-5G communication system is called a system after a 4G network (Beyond 4G Network) or a system after an LTE system (Post LTE). In order to achieve high data rates, 5G communication systems are being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Gigabit (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the propagation distance of radio waves, beamforming, massive array multiple input / output (FD-MIMO), and FD-MIMO are used in 5G communication systems. Array antenna, analog beam-forming, and large scale antenna techniques are discussed. In addition, in order to improve the network of the system, 5G communication systems have advanced small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation The development of such technology is being done. In addition, in 5G systems, Hybrid FSK and QAM Modulation (FQAM) and Slide Window Superposition Coding (SWSC), Advanced Coding Modulation (ACM), and FBMC (Filter Bank Multi Carrier) and NOMA are advanced access technologies. (non orthogonal multiple access), and sparse code multiple access (SCMA), and the like are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, and an Internet of Things (IoT) network that exchanges and processes information between distributed components such as things. The Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers and the like, is emerging. In order to implement the IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between things, a machine to machine , M2M), Machine Type Communication (MTC), etc. are being studied. In an IoT environment, intelligent Internet technology (IT) services can be provided that collect and analyze data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliances, advanced medical services, etc. through convergence and complex of existing information technology (IT) technology and various industries. It can be applied to.

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M) and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. will be. Application of cloud radio access network (cloud RAN) as the big data processing technology described above may be an example of convergence of 5G technology and IoT technology.

On the other hand, the random access operation of the terminal in the mobile communication system has a problem that can cause ambiguity in the operation of the random access message transmission.

Various embodiments of the present invention have been made to solve at least some of the above problems, and propose a method and apparatus for effectively transmitting a control message for random access in a wireless communication system.

More specifically, mobile communication such as absence of a DL grant without hybrid automatic repeat and request (HARQ) transmission information, absence of an indication supporting asynchronous UL HARQ, and asymmetric UL grant contents between RAR and general uplink data in a mobile communication system The present invention proposes a method and apparatus for transmitting a message for random access, which can remove ambiguity of a random access related standard.

In a base station of a wireless communication system according to an embodiment of the present invention, a communication method includes: receiving a random access message from a terminal; Determining a response message and downlink control information associated with the response message in response to the random access message; And transmitting the determined response message and the downlink control information, and specific information included in the downlink control information may be set to a preset value.

In a wireless communication system according to an embodiment of the present invention, a communication method of a terminal includes: transmitting a message for random access to a base station; Receiving downlink control information corresponding to the message for random access from the base station; Receiving a response message by analyzing the downlink control information without considering a value of specific information included in the downlink control information; And transmitting a terminal identification message to the base station based on the response message, and specific information included in the terminal identification message may be set to a preset value.

A base station for communicating in a wireless communication system according to an embodiment of the present invention, the transceiver for transmitting and receiving a signal; And receiving a random access message from the terminal, determining a response message and downlink control information associated with the response message in response to the random access message, and transmitting the determined response message and downlink control information to the terminal. The controller may include a controller, and specific information included in the downlink control information may be set to a preset value.

Terminal for communication in a wireless communication system according to an embodiment of the present invention, the transceiver for transmitting and receiving a signal; And transmitting a message for random access to the base station, receiving downlink control information corresponding to the message for random access from the base station, and not considering a value of specific information included in the downlink control information. And a controller configured to interpret the downlink control information, receive a response message, and transmit a terminal identification message to the base station based on the response message, wherein the specific information included in the terminal identification message is It may be set to a preset value.

According to various embodiments of the present disclosure, it is possible to effectively transmit and receive information related to initial random access.

1 is a view showing a schematic structure of a communication system according to an embodiment of the present disclosure.

2 is a diagram illustrating message transmission between a terminal and a base station for random access in an LTE system.

3 is a flowchart illustrating a random access operation of a base station according to an embodiment of the present invention.

4 is a flowchart illustrating a random access operation of a terminal according to an embodiment of the present invention.

5 is a diagram illustrating message transmission between a terminal and a base station for random access according to an embodiment of the present invention.

FIG. 6 illustrates operations of a base station and a terminal when the terminal does not specify that the terminal does not expect content not transmitted in the UL grant of the RAR according to an embodiment of the present invention.

FIG. 7 illustrates operations of a base station and a terminal when the terminal specifies that content not transmitted in the UL grant of the RAR is not expected according to an embodiment of the present disclosure.

8 is a diagram illustrating a terminal according to an embodiment of the present invention.

9 is a diagram illustrating a base station according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it should be noted that the same components in the accompanying drawings are represented by the same reference numerals as possible. In addition, detailed descriptions of well-known functions and configurations that may blur the gist of the present invention will be omitted.

In describing the embodiments herein, descriptions of technical contents that are well known in the technical field to which the present invention belongs and are not directly related to the present invention will be omitted. This is to more clearly communicate without obscure the subject matter of the present invention by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same or corresponding components in each drawing are given the same reference numerals.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments of the present invention make the disclosure of the present invention complete and the general knowledge in the technical field to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

In this case, the term '~ part' used in the present embodiment refers to software or a hardware component such as an FPGA or an ASIC, and '~ part' performs certain roles. However, '~' is not meant to be limited to software or hardware. '~ Portion' may be configured to be in an addressable storage medium or may be configured to play one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and the 'parts' may be combined into a smaller number of components and the 'parts' or further separated into additional components and the 'parts'. In addition, the components and '~' may be implemented to play one or more CPUs in the device or secure multimedia card.

1 is a diagram illustrating a schematic structure of a mobile communication system according to an embodiment of the present disclosure.

Referring to FIG. 1, a mobile communication system includes

gNBs

100, 110, 120, 130, hereinafter referred to as base stations for operating a network. In an embodiment of the present invention, the mobile communication system may be 5G. The

base stations

100, 110, 120, and 130 have

coverages

105, 115, 125, and 135 that can each provide services. The

base stations

100, 110, 120, and 130 are connected to the

terminals

140, 145, 150, and 155 through a wireless channel, and the

terminals

140, 145 within the

respective coverages

105, 115, 125, and 135. , 150, 155 may provide a wireless communication service.

Since all user traffic, including real-time services such as Voice over IP (VoIP) services over the mobile communication Internet protocol, is serviced through a shared channel, the buffer status and availability of the

terminals

140, 145, 150, and 155 are available. An apparatus for collecting and scheduling state information such as a transmission power state and a channel state is required, and the

base stations

100, 110, 120, and 130 are in charge of this. One base station typically controls a number of cells. The S-GW 170 is a device that provides a data bearer, and creates or releases a data bearer under the control of the MME 160. The MME 160 is a device in charge of various control functions as well as mobility management functions for the

terminals

140, 145, 150, and 155 and is connected to a plurality of

base stations

100, 110, 120, and 130.

Referring to FIG. 2, a signal may be transmitted and received between the terminal 200 and the base station 210, and the terminal 200 may perform a procedure for random access as described below to access the base station 210. Can be.

In operation 215, the terminal 200 may transmit a signal including a random access preamble to the base station 210 to access the base station 210.

In step 220, the base station 210 may transmit a random access response to the terminal 210 in response to the received random access preamble. More specifically, the base station 210 indexes the random access preamble sequence detected by the network in response to the detected random access attempt, and temporary cell radio-network temporary TC-RNTI (temporary cell radio-network) to be used temporarily between the terminal 200 and the network. a random access response (RAR) including at least one of an identifier, a timing correction value calculated using a random access preamble, and scheduling information of a resource to be used for message transmission by the terminal 200 in a later step. 'RAR' message may be transmitted to the terminal 200. The RAR may be transmitted with down link control information (DCI) for receiving the RAR, and the DCI may be scrambled with the RA-RNTI.

At this time, when the DL grant is transmitted in the DCI format for RAR transmission, the terminal 200 that transmits the random access preamble is not identified. Therefore, in order not to perform a hybrid automatic repeat request (HARQ) request requiring an explicit identity of the UE, DCI can be transmitted using a DCI format without HARQ-related information. For example, RAR can be transmitted using DCI format 1C. Can transmit DCI format 1C is a simplified DCI format, has no information related to HARQ, contains only the minimum resource allocation information necessary to receive the RAR, and the terminal 200 corresponds to the corresponding RA-RNTI in a common search space. The scrambled DCI may be received. .

Meanwhile, LTE uses a synchronous HARQ process for uplink transmission. That is, after the UL grant is transmitted, FDD performs uplink data transmission after 8 TTI (Transmission Time Interval), and in TDD, a subframe that performs uplink data transmission after UL grant according to TDD configuration is defined in the standard. It is decided. Accordingly, in all uplink data transmissions, for example, FDD, HARQ IDs are automatically assigned in units of 8TTIs, and in the case of the terminal 200 having synchronization with the base station 210, the UL 200 is implicit according to the TTI assigned to the UL grant. Recognizes the HARQ ID. That is, the TTI received the UL grant will soon indicate the HARQ ID that can be allocated in the corresponding TTI. Therefore, the UL grant of LTE does not explicitly inform the HARQ ID. This also applies to message transmission for random access, and does not specify a HARQ ID value even when assigning a UL grant of message (Msg) 3 transmitted by the RAR.

In step 225, the terminal 200 may transmit Msg3 to the base station 210 based on the received RAR. More specifically, when the terminal 200 receives the RAR from the base station 210, the terminal 200 may transmit a necessary message to the base station 210 using the uplink resources allocated in the RAR. The message may include identification information of the terminal. When performing message transmission using the uplink resource, HARQ may be performed through exchange of feedback information with a base station.

In step 230, the base station 210 may transmit Msg4 to the terminal 200 based on the Msg3. More specifically, Msg4 may include information for contention-resolution, and Msg 4 may be transmitted on a downlink shared channel. As a result, contention of a plurality of terminals attempting to access the system using the same random access resource may be eliminated, and the terminal 200 may exchange information with the base station 210 by connecting to the base station 210.

In the mobile communication system according to an embodiment of the present invention, the terminal may access the network using

random access procedures

215, 220, 225, and 230 similar to those of the conventional LTE as illustrated in FIG. 2. However, in the DCI format of the mobile communication standard, DL grant without HARQ transmission information may not exist as in DCI format 1C of LTE, and may be divided into B1 / B2 only. Since the DCI format B1 / B2 is a DL grant for data transmission, there is always HARQ ID and NDI (New Data Indicator) information for indicating the transmission / retransmission for HARQ support. Therefore, in the above mobile communication standard, when a UE having the same physical random access channel (PRACH) preamble ID is simultaneously received for a grant for RAR, the UE attempts to retransmit the HARQ without knowing which UE is the HARQ. Call setup may not work properly.

Referring to FIG. 3, in an embodiment, the base station may perform a random access operation through signal transmission and reception with a terminal.

In step 300, the base station may receive a message including a random access preamble for random access from the terminal. In an embodiment of the present invention, the random access preamble may be transmitted on the PRACH, and for this purpose, the base station may determine which time-frequency resource may be used for the random access preamble transmission to the UE in the cell (that is, Information about PRACH).

In step 305, the base station may determine the information to be included in the RAR to be transmitted to the terminal and the DCI information for RAR transmission based on the random access preamble received from the terminal. In this case, the RAR is an index of the random access preamble sequence detected by the network, a TC-RNTI to be temporarily used between the UE and the network, a timing correction value calculated based on the random access preamble, and a terminal for transmitting a message in a later step. It may include at least one of scheduling information of a resource to be used. The DCI for transmitting the RAR may be DCI format B1 or DCI format B2, but is not limited thereto. It is apparent that a downlink DCI for RAR reception may be used.

In step 310, the base station may set information related to HARQ included in the DCI to a specific value. The information related to HARQ included in the DCI may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. In one embodiment of the present invention, the specific value may be zero.

In step 315, the base station may transmit DCI and RAR in which the information related to the HARQ is set to a specific value to the terminal. In one embodiment, the DCI format for the RAR may be transmitted by scrambling with a random access radio-network temporary identifier (RA-RNTI), and the terminal that receives the DCI format scrambled with the RA-RNTI may be transmitted. RAR may be obtained by interpreting DCI without considering information related to HARQ included in DCI. According to an embodiment of the present disclosure, since the UE does not consider HARQ-related information set to a specific value included in the DCI, the HARQ-related operation may not be performed in an RAR transmission step in which the identity of the UE is uncertain. According to an embodiment, when the received DCI format is scrambled with RA-RNTI, the terminal may interpret the DCI without considering information related to HARQ included in the received DCI.

In step 320, the base station may receive Msg3 transmitted by the terminal based on the RAR. In an embodiment, the HARQ related information included in the Msg3 may be set to a specific value, and the specific value may be zero. The Msg3 may include information on the identity of the terminal.

In an embodiment, the base station may transmit Msg4 to the terminal based on Msg3 received from the terminal. More specifically, the Msg4 may include information for contention-resolving, and the Msg 4 may be transmitted on a downlink shared channel. As a result, contention of a plurality of terminals attempting to access the system using the same random access resource may be eliminated, and the terminal may exchange information by connecting to the base station.

Meanwhile, in the mobile communication standard, when the UL grant of the Msg3 transmitted by the RAR is allocated in the initial access process of the terminal, similar to LTE, the HARQ ID value may not be specified. However, unlike LTE, uplink transmission can operate as asynchronous HARQ like downlink transmission.

Therefore, the UL Grant transmitted to the UE in DCI format A1 / A2 for uplink data transmission may be assigned a HARQ ID, and may also include NDI (New data indicator) related information indicating that new data is transmitted. This indicates that any HARQ ID may be assigned in the TTI in which the UL grant is received. When the HARQ ID and the NDI are not specified according to the existing LTE structure in the UL transmission structure of the mobile communication requiring the HARQ ID and the NDI, the terminal receiving the UL grant through Msg3 may acquire information related to the HARQ ID. It is not possible to define the operation accordingly.

4 is a flowchart illustrating a random access operation of a terminal according to an exemplary embodiment of the present invention.

In step 400, the UE may transmit a message including the random access preamble to the base station. More specifically, the signal including the random access preamble may be transmitted for a predetermined reason, and in one embodiment, the predetermined reason may be, for example, forming a radio link through an initial connection and resuming the radio link after a radio link failure. At least one of a location measurement based on uplink synchronization and a new cell and uplink measurement through shaping and handover. According to an embodiment of the present invention, the random access preamble may be transmitted on the PRACH, and for this purpose, the base station may determine which time-frequency resources may be used for the random access preamble transmission to the UE in the cell (ie, what resources). Information about whether or not this is a PRACH.

In step 405, the terminal may receive a DCI from the base station in response to the message transmission including the random access preamble from the base station.

In step 410, the UE may acquire the corresponding RAR in the downlink data channel by analyzing the DCI without considering information related to HARQ included in the DCI received from the base station. According to an embodiment, when the UE receives the scrambled DCI with the RA-RNTI, the UE may acquire the corresponding RAR in the downlink data channel by analyzing the DCI without considering information related to HARQ included in the received DCI. . For example, the information related to HARQ included in the DCI scrambled with the RA-RNTI may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. . By analyzing the DCI without considering information related to the HARQ of the DCI, the HARQ-related operation may not be performed on the downlink data channel corresponding to the DCI.

In step 415, the UE acquires the RAR based on the DCI received from the base station, and interprets the HARQ-related information as a specific value in the UL grant related information for the transmission of Msg3 included in the obtained RAR. In one embodiment, the specific value may be zero. According to this, even if HARQ-related information is not specified in the RAR in a mobile communication system operating with asynchronous HARQ, HARQ-related operation can be smoothly performed on Msg3 transmitted by the UE by considering the value of the information as a specific value. Can be. For example, even if the HARQ process ID is not displayed in the UL grant for Msg3 of the RAR, the UE can remove the uncertainty of the operation by operating the HARQ ID = 0 and the NDI = 0.

In step 420, the UE may transmit Msg3 by setting information related to HARQ included in Msg3 to a specific value based on the obtained RAR. For example, the terminal may transmit the Msg3 to the base station using the uplink resource allocated in the RAR, where Msg3 may include information about the identity of the terminal. When Msg4 is received from the base station in response to the transmission of Msg3, contention of a plurality of terminals attempting to access the system using the same random access resource may be eliminated, and the terminal may perform connection with the base station to exchange information thereafter. Can be.

Referring to FIG. 5, the terminal 510 and the base station 500 may transmit and receive signals, and the terminal 510 may perform a procedure for random access as described below to access the base station 500. have.

In operation 515, the terminal 510 may transmit a signal including the random access preamble to the base station 500. More specifically, the signal including the random access preamble may be transmitted for a predetermined reason, and the predetermined reason may be, for example, to form a radio link through an initial connection, to form a radio link after a radio link failure, or to perform handover. It may be at least one of position measurement based on uplink synchronization and uplink measurement with a new cell.

In an embodiment of the present invention, a signal including the random access preamble may be transmitted on a PRACH. For this, the base station 500 transmits a random access preamble to a terminal 510 in a cell. Broadcasts information about which resources may be used (i.e., what resources are PRACH).

In operation 520, the base station 500 may receive a random access preamble from the terminal 510 and determine information to be included in the RAR to be transmitted to the terminal and DCI information for RAR transmission based on the received random access preamble. In this case, the RAR is an index of the random access preamble sequence detected by the network, a TC-RNTI to be temporarily used between the terminal 510 and the network, a timing correction value calculated based on the random access preamble, and the terminal 510 at a later stage. ) May include at least one of scheduling information of resources to be used for message transmission. The DCI format for transmitting the RAR may be DCI format B1 or DCI format B2, but is not limited thereto, and it is apparent that downlink DCI for RAR reception may be used.

When the DCI to be transmitted to the terminal 510 is determined, the base station 500 may set information related to HARQ included in the DCI to a specific value. The information related to HARQ included in the DCI may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. In one embodiment of the present invention, the specific value may be zero.

In step 525, the base station 500 may transmit a DCI format in which information related to HARQ is set to a specific value to the terminal 510 on the downlink control channel.

In step 535, the base station 500 may transmit the RAR determined by the terminal 510 on the downlink data channel using the DCI format. In an embodiment of the present invention, the DCI format for transmitting the RAR may be scrambled with a random access radio-network temporary identifier (RA-RNTI) and transmitted.

In step 530, the terminal 510 may not perform the HARQ-related operation on the corresponding downlink data channel by interpreting the DCI without considering the HARQ-related information included in the received DCI. In an embodiment, when the terminal 510 receives the DCI scrambled with the RA-RNTI, the terminal 510 analyzes the DCI without considering information related to HARQ included in the received DCI and acquires a corresponding RAR in the downlink data channel. can do. According to an embodiment of the present invention, the HARQ-related operation in the RAR transmission step in which the identity of the UE is uncertain because the UE 510 does not consider the HARQ-related information included in the DCI transmitted by being fixed to a specific value and scrambled with RA-RNTI. May not be performed.

In step 540, the UE 510 analyzes the DCI format to obtain a corresponding RAR in a downlink data channel, and sets information related to HARQ included in an UL grant for transmission of Msg3 included in the obtained RAR to a specific value. Consider and interpret. For example, the specific value may be zero. According to this, even if HARQ-related information is not specified in the RAR in a mobile communication system operating in asynchronous HARQ, HARQ-related operation is smoothly performed for Msg3 transmitted by the terminal by the terminal 510 considering the value of the information as a specific value. This can be done. For example, even if the HARQ process ID is not displayed in the UL grant for Msg3 explicitly included in the RAR, the UE 510 may remove HARQ ID = 0 and NDI = 0, thereby removing the uncertainty of operation. .

In step 545, the terminal 510 may transmit Msg3 by setting information related to HARQ to a specific value based on the UL grant included in the RAR received from the base station. The Msg3 may be transmitted to a base station using an uplink resource allocated in the RAR, and in this case, the Msg3 may include information on the identity of the terminal. When receiving the Msg4 from the base station in response to the transmission of the Msg3, the contention of a plurality of terminals attempting to access the system using the same random access resources can be eliminated, the terminal 510 is connected to the base station 500 Information can then be exchanged.

Meanwhile, according to an embodiment of the present invention, the RAR transmitted by the base station corresponding to the signal including the random access preamble received from the terminal is required for the DCI format as an UL grant for general uplink data, but is not included in the RAR. There may be unnecessary information. For example, the unnecessary information may include at least one of a beam switch indication, an uplink dual PCRS, an HARQ ID, and an NDI. In the existing LTE, the unnecessary information may be deleted and transmitted in DCI format 1C, but in the mobile communication system according to an embodiment of the present invention, unnecessary information may be transmitted to the terminal without deleting the unnecessary information in the RAR.

Referring to FIG. 6, in an embodiment, the base station 600 may perform a random access operation through signal transmission and reception with the terminal 610.

In operation 615, the terminal 610 may transmit a signal including the random access preamble to the base station 600. More specifically, the signal including the random access preamble may be transmitted for a predetermined reason, and the predetermined reason may be, for example, to form a radio link through an initial connection, to form a radio link after a radio link failure, or to perform handover. It may be at least one of position measurement based on uplink synchronization and uplink measurement with a new cell.

In an embodiment of the present invention, a signal including the random access preamble may be transmitted on a PRACH. For this purpose, the base station 600 transmits a random access preamble to a terminal 610 in a cell. Broadcasts (i.e., what resources are PRACH).

In operation 620, the base station 600 receives a signal including a random access preamble from the terminal 610, and determines information to be included in the RAR to be transmitted to the terminal and DCI information for RAR transmission based on the received random access preamble. Can be. In this case, the RAR is the index of the random access preamble sequence detected by the network, the TC-RNTI temporarily used between the terminal 610 and the network, a timing correction value calculated based on the random access preamble, and the terminal 610 at a later stage. ) May include at least one of scheduling information of resources to be used for message transmission. The DCI format for transmitting the RAR may be DCI format B1 or DCI format B2, but is not limited thereto, and it is apparent that downlink DCI for RAR reception may be used. When the DCI to be transmitted to the terminal 610 is determined, the base station 600 may set information related to HARQ included in the DCI to a specific value. The information related to HARQ included in the DCI may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. In one embodiment of the present invention, the specific value may be zero.

In step 625, the base station 600 may transmit a DCI format in which information related to HARQ is set to a specific value to the terminal 610 on the downlink control channel. In one embodiment, the DCI format for transmitting the RAR may be scrambled to RA-RNTI and transmitted.

In step 635, the base station 600 may transmit the RAR determined by the terminal 610 on the downlink data channel using the DCI format.

In operation 630, the UE may acquire the corresponding RAR on the downlink data channel by analyzing the DCI without considering information related to HARQ included in the received DCI. In an embodiment, when the terminal 610 receives the DCI scrambled with the RA-RNTI from the base station, the terminal 610 interprets the DCI without considering information related to HARQ included in the received DCI and downlinks the corresponding RAR to the downlink data channel. Can be obtained from. In an embodiment, the information related to the HARQ of the DCI scrambled with the RA-RNTI may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. have. By analyzing the DCI without considering information related to the HARQ included in the DCI, the HARQ-related operation may not be performed on the downlink data channel corresponding to the DCI.

Meanwhile, in one embodiment, the RAR is an index of the random access preamble sequence detected by the network, a TC-RNTI temporarily used between the terminal 610 and the network, a timing correction value calculated using a random access preamble, and In a subsequent step, the terminal 610 may include at least one of scheduling information of resources to be used for message transmission. However, the RAR may include information that is necessary for the DCI format as a UL grant for general uplink data but is unnecessary for the RAR. For example, the unnecessary information may include at least one of a beam switch indication, an uplink dual PCRS, an HARQ ID, and an NDI.

According to an embodiment of the present invention, the UE may assume that the operation implicitly exists for information existing in the DCI format but not present in the UL grant of the RAR.

In step 640, the terminal 610 is configured for the beam change (beam change) that may be present when receiving the RAR from the base station 600 for the beam switch indication of the information present in the DCI format but not in the UL grant of the RAR And implicitly prepare necessary actions in hardware. Also, in the embodiment, when the information indicating the beam change is received, the terminal may perform an operation for beam change based on the information, at least one of the obtained beam-related measurement information and the information indicating the beam change It is possible to select a beam to be changed based on.

In step 645, the terminal 610 may reset software and hardware again if there is no beam switch instruction in the RAR.

In operation 650, the terminal 610 may transmit Msg3 by setting information related to HARQ to a specific value based on the UL grant of the RAR received from the base station 600. The terminal may transmit the Msg3 to the base station using the uplink resources allocated in the RAR, where the Msg3 may include the identity of the terminal 610. When the terminal 610 receives the Msg4 from the base station in response to the transmission of the Msg3, the contention of a plurality of terminals attempting to access the system using the same random access resources can be eliminated, the terminal 610 is a base station 600 ) And then exchange information.

FIG. 7 illustrates operations of a base station and a terminal in the case where operation of a terminal as in the embodiment of the present specification is assumed for content not included in a UL grant of an RAR according to an embodiment of the present invention.

Referring to FIG. 7, in an embodiment, the base station 700 may perform a random access operation through signal transmission and reception with the terminal 710.

In operation 715, the terminal 710 may transmit a signal including the random access preamble to the base station 700. More specifically, the signal including the random access preamble may be transmitted for a predetermined reason, and the predetermined reason may be, for example, to form a radio link through an initial connection, to form a radio link after a radio link failure, or to perform handover. It may be one of position measurement based on uplink synchronization and uplink measurement with a new cell.

In an embodiment of the present invention, a signal including the random access preamble may be transmitted on a PRACH. For this purpose, the base station 700 transmits a random access preamble to a terminal 710 in a cell. Broadcasts information about which resources may be used (i.e., what resources are PRACH).

In operation 720, the base station 700 receives a signal including a random access preamble from the terminal 710, and determines information to be included in the RAR to be transmitted to the terminal and DCI information for RAR transmission based on the received random access preamble. Can be. In this case, the RAR is an index of the random access preamble sequence detected by the network, a TC-RNTI to be used temporarily between the terminal 710 and the network, a timing correction value calculated based on the random access preamble, and the terminal 710 at a later stage. ) May include at least one of scheduling information of resources to be used for message transmission. The DCI format for transmitting the RAR may be DCI format B1 or DCI format B2, but is not limited thereto, and it is apparent that downlink DCI for RAR reception may be used. When the DCI to be transmitted to the terminal 710 is determined, the base station 700 may set information related to HARQ included in the DCI to a specific value. The information related to HARQ included in the DCI may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. In one embodiment of the present invention, the specific value may be zero.

In step 725, the base station 700 may transmit a DCI format in which information related to HARQ is set to a specific value to the terminal 710 on the downlink control channel. In one embodiment, the DCI format for transmitting the RAR may be scrambled to RA-RNTI and transmitted.

In step 735, the base station 700 may transmit the RAR determined by the terminal 710 on the downlink data channel using the DCI format.

In operation 730, the UE may acquire the corresponding RAR on the downlink data channel by analyzing the DCI without considering information related to HARQ included in the received DCI. In an embodiment, when the DCI format received from the base station is scrambled with RA-RNTI, the terminal 710 analyzes the DCI without considering information related to HARQ included in the received DCI and downlinks the corresponding RAR to downlink data. Can be obtained from the channel. In an embodiment, the information related to HARQ of the DCI format may be at least one of a HARQ ID, a new data indication (NDI), or a bit-mapping index for HARQ-ACK multiplexing. By analyzing the DCI without considering information related to the HARQ included in the DCI, the HARQ-related operation may not be performed on the downlink data channel corresponding to the DCI.

Meanwhile, in one embodiment, the RAR is an index of the random access preamble sequence detected by the network, a TC-RNTI temporarily used between the terminal 710 and the network, a timing correction value calculated using a random access preamble, and In a subsequent step, the terminal 710 may include at least one of scheduling information of resources to be used for message transmission. However, the RAR may include information that is necessary for the DCI format as a UL grant for general uplink data but is unnecessary for the RAR. For example, the unnecessary information may include at least one of a beam switch indication, an uplink dual PCRS, an HARQ ID, and an NDI.

According to an embodiment of the present invention, the UE may be explicitly defined as not performing a corresponding operation on information present in the DCI format for the general uplink data but not present in the UL grant of the RAR.

In step 740, the UE may be explicitly defined that the beam switch indication information does not exist in the received RAR with respect to the beam switch indication among information existing in the DCI format but not present in the UL grant of the RAR.

In step 745, the terminal may prepare for transmission of Msg3 without additional setup of software and hardware related to the beam.

In operation 750, the terminal 710 may transmit Msg3 by setting information related to HARQ to a specific value based on the UL grant of the RAR received from the base station 700. The terminal may transmit the Msg3 to the base station using the uplink resources allocated in the RAR, wherein the Msg3 may include the identity of the terminal. When Msg4 is received from the base station in response to the transmission of Msg3, contention of a plurality of terminals attempting to access the system using the same random access resource may be eliminated, and the terminal 710 performs a connection with the base station 700. Information can then be exchanged.

Referring to FIG. 8, the terminal of the embodiment may include a transceiver 810, a terminal controller 815, and a storage 820.

The transceiver 810 may transmit and receive a signal with a base station and another entity. According to an embodiment of the present invention, the transceiver 810 transmits a signal including a random access preamble for random access to the base station and Msg3 corresponding to the RAR transmitted from the base station, and transmits the RAR and Msg4 from the base station. Can be received.

The storage unit 820 may store at least one of information related to a terminal or information transmitted and received through the transceiver 810. According to an embodiment of the present invention, the storage unit 820 may store information necessary for the HARQ operation.

The terminal controller 815 may be connected to the transceiver and the storage, control the operation of the terminal, and control the entire terminal to perform the operation related to the terminal described in the above embodiment. The terminal controller 815 may include at least one processor.

Referring to FIG. 9, an embodiment of the terminal may include a transceiver 910, a base station controller 915, and a storage 920.

The transceiver 910 may transmit and receive a signal with a terminal and another entity. According to an embodiment of the present disclosure, the transceiver 910 receives Msg3 from the terminal in response to a signal including a random access preamble for random access from the terminal and an RAR transmitted to the terminal, and receives the RAR and Msg4 from the terminal. Can be sent to.

The storage unit 920 may store at least one of information related to a base station or information transmitted and received through the transceiver 910. According to an embodiment of the present invention, the storage unit 920 may store information required for the HARQ operation.

The base station controller 915 may be connected to the transceiver and the storage unit, control the operation of the base station, and control the entire base station so as to perform the operation related to the base station described in the above embodiment. The base station controller 915 may include at least one processor.

On the other hand, the present specification and the drawings have been described with respect to the preferred embodiments of the present invention, although specific terms are used, it is merely used in a general sense to easily explain the technical details of the present invention and help the understanding of the invention, It is not intended to limit the scope of the invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims

A communication method in a base station of a wireless communication system,

Receiving a random access message from a terminal;

Determining a response message and downlink control information associated with the response message in response to the random access message; And

Transmitting the determined response message and the downlink control information;

The specific information included in the downlink control information is set to a preset value.
The method of claim 1,

The specific information is at least one of a HARQ ID, a new data indication (NDI), a bit-mapping index for HARQ-ACK multiplexing, a beam switch indication, or an uplink dual PCRS. ,

And when the downlink control information is scrambled with a random access-radio-network temporary identifier (RA-RNTI), the specific information included in the downlink control information is set to the preset value.
The method of claim 1,

And receiving a message including identification information of the terminal from the terminal without considering the specific information set to the preset value.
The method of claim 1,

The preset value is 0.
In a communication method of a terminal in a wireless communication system,

Transmitting a message for random access to the base station;

Receiving downlink control information corresponding to the message for random access from the base station;

Receiving a response message by analyzing the downlink control information without considering a value of specific information included in the downlink control information; And

Transmitting a terminal identification message to the base station based on the response message;

The specific information included in the terminal identification message is set to a preset value.
The method of claim 5, wherein

When the downlink control information is scrambled with a random access-radio-network temporary identifier (RA-RNTI), the downlink control information is interpreted without considering the value of the specific information included in the downlink control information. Communication method.
The method of claim 5, wherein

The specific information included in the downlink control information and the specific information included in the terminal identification message include a HARQ ID, a new data indication (NDI), a bit-mapping index for HARQ-ACK multiplexing, and a beam switch. At least one of a beam switch indication or an uplink dual PCRS.
The method of claim 5, wherein

The preset value is 0
A base station for communicating in a wireless communication system,

Transmitting and receiving unit for transmitting and receiving a signal; And

A control unit configured to receive a random access message from a terminal, determine a response message and downlink control information related to the response message in response to the random access message, and transmit the determined response message and downlink control information to the terminal. Including,

Specific information included in the downlink control information is set to a preset value.
The method of claim 9,

The specific information is at least one of a HARQ ID, a new data indication (NDI), a bit-mapping index for HARQ-ACK multiplexing, a beam switch indication, or an uplink dual PCRS. ,

And the specific information included in the downlink control information is set to the preset value when the downlink control information is scrambled with a random access-radio-network temporary identifier (RA-RNTI).
The method of claim 9,

The control unit is further configured to receive a message including identification information of the terminal from the terminal without considering the specific information set to the preset value.
The method of claim 9,

The preset value is 0.
A terminal for communicating in a wireless communication system,

Transmitting and receiving unit for transmitting and receiving a signal; And

Transmitting a message for random access to a base station, receiving downlink control information corresponding to the message for random access from the base station, and not considering a value of specific information included in the downlink control information; A control unit configured to interpret downlink control information, receive a response message, and transmit a terminal identification message to the base station based on the response message;

Specific information included in the terminal identification message is set to a preset value.
The method of claim 13,

Specific information included in the downlink control information and specific information included in the terminal identification message include a HARQ ID, a new data indication (NDI), a bit-mapping index for HARQ-ACK multiplexing, and a beam switch indication. at least one of a beam switch indication or an uplink dual PCRS,

When the downlink control information is scrambled with a random access-radio-network temporary identifier (RA-RNTI), the downlink control information is interpreted without considering the value of the specific information included in the downlink control information. Terminal.
The method of claim 13,

The preset value is 0 terminal.