Method and apparatus for transmitting and receiving random access preamble in wireless cellular communication system

Abstract

A communication method for combining a 5G communication system supporting a higher data transmission rate than a 4G system with IoT technology and a system using the same are disclosed. Based on 5G communication technology and IoT-related technology, the disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety-related services, etc.). A method and apparatus for supporting a reserved resource are disclosed, and according to the present invention, a method for a base station in a communication system includes the steps of transmitting reserved resource-related information to a terminal; determining whether to map a first signal to the reserved resource and a resource overlapping the first signal to be transmitted to the terminal based on the reserved resource-related information; and transmitting the first signal to the terminal based on the result of the determination.

Description

TECHNICAL FIELD

[0001] The present application relates to a wireless communication system, and more particularly, to a method and apparatus for allowing a terminal to initially access a network in a next-generation mobile communication system. BACKGROUND

[0002] To meet increasing demand with respect to wireless data traffic since the deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a "beyond 4G network" or a "post LTE system." 5G communication systems are considered to be implemented not only to'upgrade existing legacy technologies but also to be implemented to use a new air interface and a new radio network architecture that can be compatible with 4G LTE systems. For example, 5G communication systems are considered to be implemented not only in lower frequency bands (e.g., several GHz bands) but also in higher frequency bands (e.g., several tens of GHz bands), to enable implementation of a mobile broadband service that supports higher data rates beyond those of 4G communication systems. To this end, 5G communication systems are considered to be implemented using technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimension MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas. In addition, 5G communication systems are considered to be implemented using technologies such as advanced small cells, cloud radio access networks (RANs), ultra-dense networks, a high-level network of base stations (BSs), a network of network (NN), cooperative communication, coordinated multi-points (CoMP), interference mitigation, mobile networks, and device-to-device (D2D) communication. Furthermore, 5G communication systems are considered to be implemented not only to support voice and packet data calls but also to support machine type communication (MTC), which is also called the Internet of Things (IoT), a vehicle-to-everything (V2X) service, a vehicle-to-vehicle (V2V) service, a vehicle-to-network (V2N) service, and the like.

[0003] The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of Things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE), which is a combination of the IoT technology and the Big Data processing technology through connection with a cloud server, has emerged as a new paradigm. As technology elements, such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology", and "security technology" have been demanded for IoT implementation, a sensor network, a Machine-to-Machine (M2M) communication, Machine Type Communication (MTC), and the like have been researched. Such an IoT environment can provide intelligent Internet technology services that create a new value through collection and analysis of data generated from connected things. The IoT can be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances, and advanced medical services.

[0004] According to these developments, various efforts have been made to apply 5G communication systems to IoT networks. For example, technologies, such as beamforming, MIMO, and array antennas can be implemented to sensor networks, machine type communication (MTC), and machine-to-machine (M2M) communication. Big data processing technology can also be considered an example of convergence between the 5G technology and the IoT technology by applying cloud radio access network (RAN) as described above.

[0005] To meet various user and service quality requirements in a new radio (NR) communication system (which is interchangeably referred to as an NR system and a 5G system), it is important to design a system for supporting different transmission / reception schemes and services having various transmission / reception parameters and to eliminate the limitations of the current system that can limit services to be added in the future in consideration of forward compatibility. To increase a data rate in the NR system, it is considered to transmit a signal in a wider frequency band higher than 6 GHz, and for this, a method and an apparatus for efficiently performing a directional beam-based random access operation are required. In addition, a resource allocation method and an apparatus that support forward compatibility of 5G and super 5G services in the NR system are required. Further, in consideration of the NR system operating in both a high frequency band and a low frequency band, a new reference signal for estimating phase noise is required. SUMMARY

[0006] TECHNICAL PROBLEM

[0007] The present application aims to provide a directional beam-based random access method and apparatus for use in a frequency band higher than 6 GHz.

[0008] The present application also aims to provide a data transmission / reception method for a 5G-oriented communication service, and in particular, to provide a data transmission / reception method and apparatus for a terminal for use on resources allocated in consideration of forward compatibility of 5G and super 5G services in the future.

[0009] The present application also aims to provide a method for transmitting a time-continuous reference signal.

[0010] TECHNICAL SOLUTION

[0011] According to an aspect of the present application, a method of a base station in a communication system includes transmitting information about a reserved resource to a terminal, determining whether to map a first signal to be transmitted to the terminal to a location where the reserved resource overlaps with a resource for transmitting the first signal to the terminal based on the information about the reserved resource, and transmitting the first signal to the terminal based on the determination result. Preferably, the first signal is at least one of data or a reference signal. Preferably, the reserved resource information includes information indicating at least one of a time resource and a frequency resource of the reserved resource and information indicating that rate matching or puncturing is applied on the overlapping resource, and the method of the base station further includes transmitting information indicating whether to use the reserved resource to the terminal.

[0012] According to another aspect of the present application, a method of a terminal in a communication system includes receiving information about a reserved resource from a base station, and receiving a first signal from the base station on a resource other than a resource overlapping with the reserved resource based on the information about the reserved resource.

[0013] According to another aspect of the present application, a base station of a communication system includes a transceiver configured to transmit and receive a signal, and a controller connected to the transceiver and configured to control transmitting information about a reserved resource to a terminal, determining whether to map a first signal to be transmitted to the terminal to a location where the reserved resource overlaps with a resource for transmitting the first signal to the terminal based on the information about the reserved resource, and transmitting the first signal to the terminal based on the determination result.

[0014] According to yet another aspect of the present application, a terminal of a communication system includes a transceiver configured to transmit and receive a signal, and a controller connected to the transceiver and configured to control receiving information about a reserved resource from a base station, and receiving a first signal from the base station on a resource other than a resource overlapping with the reserved resource based on the information about the reserved resource.

[0015] Technical Effects

[0016] The random access method for use in a communication system supporting a dynamic TDD operation according to the present application is advantageous in improving frequency utilization efficiency through the dynamic TDD operation and at the same time allowing a terminal to effectively perform a random access procedure in an idle mode. As described above, the present application is also advantageous in allowing a terminal not knowing its own state to perform a beam-based random access procedure in a system supporting beam-based data transmission / reception to secure coverage (such as a frequency band higher than 6 GHz).

[0017] The data transmission / reception method and apparatus of the present application are advantageous in that a 5G-oriented communication service is supported. In particular, the data transmission / reception method and apparatus of the present application are advantageous in that a terminal can operate on resources allocated in consideration of future forward compatibility for 5G and beyond 5G services.

[0018] The time-continuous reference signal transmission method of the present application is advantageous in that channel estimation is effectively performed in a 5G wireless communication capable of operating in both a high frequency band and a low frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a diagram illustrating a basic time-frequency resource structure for transmitting a downlink data or control channel in an LTE and LTE-A system;

[0020] Figure 2 is a diagram illustrating a basic time-frequency resource structure for transmitting an uplink data or control channel in an LTE and LTE-A system;

[0021] Figure 3 is a diagram illustrating a radio resource of 1 RB which is a minimum downlink scheduling unit in an LTE and LTE-A system;

[0022] Figure 4 is a diagram illustrating a structure of a TCRS;

[0023] Figure 5 is a diagram illustrating a position of a DMRS and a TCRS proposed in the present application in a time-frequency domain;

[0024] Figure 6 is a diagram illustrating a method for allocating transmission layers to a UE;

[0025] Figure 7 is a diagram illustrating an exemplary method for configuring 4 different TCRSs;

[0026] Figure 8 is a diagram illustrating an exemplary TCRS allocation;

[0027] Figure 9 and Figure 10 is a block diagram illustrating a configuration of a UE and a base station according to an embodiment of the present application;

[0028] Figure 11 is a signal flow diagram illustrating a random access procedure between a UE and a base station in a legacy LTE system;

[0029] Figure 12 is a diagram illustrating a time-domain transmission resource structure considered in an NR system;

[0030] Figure 13 is a diagram illustrating a random access preamble transmission resource configuration method for a base station used by a terminal in an LTE system;

[0031] Figure 14 is a diagram illustrating an exemplary directional beam-based transmission considered in an NR system;

[0032] Figure 15 is a diagram of an exemplary beam sweeping scheme for a base station to sweep transmission beams to transmit a synchronization and broadcast channel in a downlink subframe;

[0033] Figure 16 is a diagram of an exemplary beam sweeping scheme for a base station to sweep reception beams to receive a random access preamble transmitted by a UE in an uplink subframe;

[0034] Figure 17 is a signal flow diagram illustrating a random access preamble transmission procedure of a terminal in an NR system according to an embodiment of the present application;

[0035] Figure 18 is a signal flow diagram illustrating a random access preamble transmission procedure of a terminal in an NR system according to another embodiment of the present application;

[0036] Figure 19 is a signal flow diagram illustrating a random access preamble transmission procedure between a base station and a UE using directional beams to communicate with each other in an NR system according to an embodiment of the present application;

[0037] Figure 20 and Figure 21 is a diagram illustrating a UE and a base station configured to implement an embodiment of the present application;

[0038] Figure 22 is a basic time-frequency resource structure for transmitting a downlink data or control channel in an LTE system;

[0039] Figure 23 is a diagram illustrating an example of multiplexing services supported in a 5G system into the system;

[0040] Figure 24 and Figure 25 is a diagram illustrating a communication system according to embodiments 3-1 and 3-2 of the present application; Figure 26 is a diagram illustrating a problem situation to be addressed by the present application;

[0041] Figure 27 is a diagram illustrating embodiment 2-1 of the present application;

[0042] Figure 28a and Figure 28bis a flow diagram illustrating operations of a base station and a UE according to Embodiment 3-1 of the present application;

[0043] Figure 29 is a diagram illustrating Embodiment 3-2 of the present application;

[0044] Figure 30a and Figure 30b is a flow diagram illustrating operations of a base station and a UE according to Embodiment 3-2 of the present application;

[0045] Figure 31a and Figure 31b is a flow diagram illustrating operations of a base station and a UE according to Embodiment 3-3 of the present application;

[0046] Figure 32 is a diagram illustrating Embodiment 3-4 of the present application;

[0047] Figure 33 is a diagram illustrating Embodiment 3-5 of the present application;

[0048] Figure 34 is a block diagram of a base station according to an embodiment of the present application; and

[0049] Figure 35 is a block diagram of a UE according to an embodiment of the present application. DETAILED DESCRIPTION

[0050] Exemplary embodiments of the present application are described in detail with reference to the attached drawings.

[0051] Detailed descriptions of technical specifications well known in the art and not directly related to the present application can be omitted to avoid obscuring the subject matter of the present application. This is intended to omit unnecessary descriptions in order to clarify the subject matter of the present application.

[0052] For the same reason, some elements are enlarged, omitted, or simplified in the drawings, and in practice, the elements can have different sizes and / or shapes from those shown in the drawings. Throughout the drawings, the same or equivalent parts are indicated by the same reference numerals.

[0053] The features and advantages of the present application, as well as the method of achieving the same, can be understood by reference to the following detailed description of exemplary embodiments and the accompanying drawings. The present application may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these exemplary embodiments are provided so that the disclosure of the present application will be thorough and complete, and will fully convey the concept of the present application to those skilled in the art, and the present application will only be defined by the appended claims. Identical reference numerals refer to the same elements throughout the specification.

[0054] It should be understood that each block of the flowchart and / or block diagram illustrations, and combinations of blocks in the flowchart and / or block diagram illustrations, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. These computer program instructions can also be stored in a non-transitory computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the non-transitory computer-readable medium produce an article of manufacture including instructions which implement the functions / acts specified in the flowchart and / or block diagram block or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0055] Furthermore, the respective blocks can illustrate portions of a module, segment, or code that includes at least one or more executable instructions for performing the specified logical function(s). Moreover, it should be noted that the functions of the blocks can be performed in serial, in parallel, or in some other order as can be desirable.

[0056] According to various embodiments of the present application, the term "module" means, but is not limited to, a software or hardware component, such as a field programmable gate array (FPGA) or application specific integrated circuit (ASIC), which performs certain tasks. A module can advantageously be configured to reside on the addressable storage medium and configured to execute on one or more processors. Thus, a module can include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality of the components and modules can be combined into fewer components and modules or further separated into additional components and modules. In addition, the components and modules can be implemented such that they execute one or more CPUs in a device or a secure multimedia card. A module can include one or more processors.

[0057] <Embodiment 1>

[0058] The present application relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting time-continuous reference signals.

[0059] In a wireless communication system, a base station must transmit a reference signal to be used by a terminal for estimating a channel. The terminal performs demodulation on a signal received through a channel estimated based on the reference signal. The terminal can check a channel state based on the reference signal and report the channel state to the base station. Generally, a reference signal is transmitted in a frequency-time resource interval determined in consideration of a maximum delay spread and a maximum Doppler spread of a channel. If the frequency-time resource interval for transmitting a reference signal is narrowed, this can improve channel estimation performance and thereby improve signal demodulation performance, but can also negatively increase reference signal overhead, thereby limiting data rate.

[0060] A conventional 4G LTE system operating in a frequency band of 2 GHz uses a reference signal such as a cell-specific reference signal (CRS) and a demodulation reference signal (DMRS). If a reference signal is transmitted with an interval of m subcarriers in each orthogonal frequency-division multiplexing (OFDM) symbol in a frequency domain with an interval of n OFDM symbols in a time domain, assuming use of a normal cyclic prefix (CP), a frequency-time resource interval of a CRS of antenna ports 1 and 2 can be expressed as (m, n) = (3, 4). Assuming use of a normal CP, a frequency-time resource interval of a DMRS can be expressed as (m, n) = (5, 7).

[0061] For a 5G wireless communication system, unlike an LTE system, a system operating in a frequency band higher than 6 GHz is being considered in addition to a system operating below 6 GHz. A 5G system should be designed in consideration of channel characteristics varying with a frequency band. 5G wireless communication also has to meet stringent requirements such as low latency and high mobility. Minimizing interference and overhead caused by a reference signal in a 5G system is also important; thus, a method for minimizing always-on transmission of a reference signal is needed. To achieve the above-described goal, the present invention proposes a method for a terminal to efficiently perform channel estimation by employing a time-continuous reference signal (TCRS).

[0062] Mobile communication systems have evolved into high-speed high-quality packet data communication systems capable of providing data and multimedia services in addition to early voice-oriented services (such as High Speed Packet Access (HSPA) defined in the 3rd Generation Partnership Project (3GPP), LTE (or Evolved Universal Terrestrial Radio Access (E-UTRA) and LTE-Advanced (LTE-A); High Rate Packet Data (HRPD) defined in the 3rd Generation Partnership Project-2 (3GPP2); and 802.16e defined in IEEE). At the same time, 5G or NR standardization is being developed for a 5G wireless communication system.

[0063] An LTE system, which is one of representative broadband wireless communication systems, uses orthogonal frequency division multiplexing (OFDM) in a downlink (DL) and uses single carrier frequency division multiple access (SC-FDMA) in an uplink (UL). The term "uplink" refers to a radio link for transmitting data or control signals from a terminal interchangeably called a user equipment (UE) and a mobile station (MS) to a radio base station (BS) interchangeably called an evolved node B (eNB) base station (BS), and the term "downlink" refers to a radio link for transmitting data or control signals from a base station to a terminal. Such a multiple access scheme is characterized in that time-frequency resources for transmitting user-specific data and control information are allocated without overlapping each other, i.e., orthogonality is maintained in order to distinguish user-specific data and control information.

[0064] Figure 1 is a diagram showing a basic time-frequency resource structure for transmitting a downlink data or control channel in an LTE and LTE-A system.

[0065] In Figure 1 , the horizontal axis represents time and the vertical axis represents frequency. The minimum transmission unit in the time domain is an OFDM symbol, and N symb OFDM symbols 102 form a slot 106, and 2 slots form a subframe 105. Each slot spans 0.5 ms, and each subframe spans 1.0 ms. A radio frame 114 is a time unit consisting of 10 subframes. In the frequency domain, the minimum transmission unit is a subcarrier, and the total system transmission bandwidth consists of N BW subcarriers 104.

[0066] In the time-frequency resource structure, a basic resource unit is a resource element (RE) indicated by an OFDM symbol index and a subcarrier index. A resource block (RB) (or a physical resource block (PRB)) 108 is defined by N symb consecutive OFDM symbols 102 in the time domain and N RB consecutive subcarriers 110 in the frequency domain. That is, one RB 108 consists of N symb × N RB REs 112. In general, an RB is the minimum data transmission unit. In general, in an LTE system, N symb = 7, N RB = 12 and N BW and N RB are proportional to the system transmission bandwidth. A data rate increases in proportion to the number of RBs scheduled for a terminal.

[0067] Six transmission bandwidths are defined for the LTE system. In the case of an FDD system in which the downlink and the uplink are separated in frequency, the downlink transmission bandwidth and the uplink transmission bandwidth can be different from each other. The channel bandwidth indicates an RF bandwidth compared to the system transmission bandwidth. Table 1 shows the relationship between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system having a 10 MHz channel bandwidth uses a transmission bandwidth of 50 RBs.

[0068] [Table 1]

[0069]

[0070] Figure 2 is a diagram illustrating a basic time-frequency resource structure for transmitting uplink data or a control channel in the LTE and LTE-A systems.

[0071] In Figure 2 , the horizontal axis indicates time, and the vertical axis indicates frequency. The minimum transmission unit in the time domain is an SC-FDMA symbol, and N symb SC-FDMA symbols 202 form a slot 206. Two slots 204 form a subframe 205. The minimum transmission unit in the frequency domain is a subcarrier, and the total system transmission bandwidth is composed of N BW subcarriers 204. N BW is proportional to the system transmission bandwidth.

[0072] In the time-frequency domain, the basic resource unit is an RE 212, and each RE is defined by one SC-FDMA symbol index and one subcarrier index. An RB 208 is defined by N symb consecutive SC-FDMA symbols in the time domain and N symb consecutive subcarriers in the frequency domain. Accordingly, one RB is composed of N symb × N symb REs. Generally, the minimum data or control information transmission unit is an RB. A physical uplink control channel is mapped to a frequency region corresponding to one RB and is transmitted during the time period of one subframe.

[0073] Figure 3 is a diagram illustrating a radio resource of 1 RB which is the minimum downlink scheduling unit in the LTE and LTE-A systems. As Figure 3 indicated, different types of signals can be transmitted on the radio resource, which are as follows.

[0074] 1. Cell-specific reference signal (CRS): This is a periodically broadcasted reference signal commonly used by all UEs within one cell.

[0075] 2. Demodulation Reference Signal (DMRS): This is a reference signal transmitted for a specific terminal and used only for transmitting data to the corresponding UE. Up to 8 DMRS antenna ports can be supported. In LTE-A, antenna ports 7 to 14 are allocated for DMRS, and these ports maintain orthogonality with code division multiplexing (CDM) or frequency division multiplexing (FDM) to avoid interference with each other.

[0076] 3. Physical Downlink Shared Channel (PDSCH): This is a downlink channel for transmitting traffic from an eNB to a UE using REs in the data region to which a reference signal is not mapped.

[0077] 4. Channel State Information Reference Signal (CSI-RS): This is a reference signal transmitted for UEs in a cell to use for channel state measurement. Multiple CSI-RSs can be transmitted within a cell.

[0078] 5. Other control channels: These include a Physical Hybrid-ARQ Indicator Channel (PHICH), a Physical Control Format Indicator Channel (PCFICH), and a Physical Downlink Control Channel (PDCCH); an eNB can provide control information to a UE for receiving data on a PDSCH or transmitting a HARQ ACK / NACK corresponding to data transmitted in an uplink.

[0079] Considering that the CRS and DMRS among the above signals are reference signals for demodulating a received signal through channel estimation and that channel estimation performance directly affects demodulation performance, a frequency-time resource interval for transmitting a reference signal is maintained.

[0080] For a 5G wireless communication system, unlike an LTE system, a system operating in a frequency band higher than 6 GHz is being considered in addition to a system operating below 6 GHz. The 5G system should be designed considering channel characteristics that vary with a frequency band. 5G wireless communication also has to meet stringent requirements such as low latency and high mobility. Minimizing interference and overhead caused by a reference signal in a 5G system is also important; thus, a method for minimizing a transmission duration of a reference signal is required. To achieve this goal, the present invention provides a method for a terminal to efficiently perform channel estimation by employing a time-continuous reference signal (TCRS).

[0081] Exemplary embodiments of the present invention are described in detail with reference to the accompanying drawings. Although the description relates to an LTE or LTE-A system, the present invention can be equally applied to other communication systems having a similar technical background and channel format. Examples of such systems can include 5G mobile communication technology (New Radio (NR)). In this case, the basic structure of a time-frequency resource for downlink and uplink transmission can be different from that of the LTE system. Figure 1 and Figure 2those depicted. The signals transmitted in the downlink and uplink can also differ in type from the reference Figure 3 Those skilled in the art will understand that the present application can be applied to other communication systems with slight modifications without departing from the spirit and scope of the present application.

[0082] Detailed descriptions of well-known functions and structures incorporated herein can be omitted to avoid obscuring the subject matter of the present application. Furthermore, the following terms are defined in consideration of the functions in the present application, and they can vary according to the user's or operator's intention, usage, etc. Therefore, the definitions should be made on the basis of the overall content of the present specification. In the following description, the term "base station (BS)" denotes an entity for allocating resources to a terminal, and is intended to include at least one of a node B, an evolved node B (eNB), a radio access unit, a base station controller, and a network node. The term "terminal" is intended to include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, and a multimedia system having a communication function.

[0083] In the following description, for convenience of explanation, the time continuous reference signal is replaced by its acronym TCRS. However, according to the user's intention and the purpose of use of the reference signal, the term TCRS can be expressed by a different term. For example, the term "TCRS" can be replaced by another term such as "channel tracking reference signal (CTRS)", "phase noise reference signal (PNRS)", "phase noise compensation reference signal (PCRS)", and "phase reference signal (PRS)". The description is made with reference to the specific term "TCRS" to help explain and understand the present application, but it does not limit the scope of the present application. It is obvious to those skilled in the art that the reference signal can be practiced based on the technical idea of the present application.

[0084] Embodiment 1-1 of the present application relates to the structure and location of TCRS in the time-frequency domain. Embodiment 1-2 of the present application relates to a method for a base station to configure TCRS. Embodiment 1-3 of the present application relates to UE operation based on the configured TCRS.

[0085] Embodiment 1-1

[0086] Embodiment 1-1 relates to the structure and location of TCRS (as the reference signal proposed in the present application) in the time-frequency domain.

[0087] Figure 4 is a diagram showing the structure of TCRS. As Figure 4As shown, in the time-frequency domain, the TCRS 410 is transmitted on a portion of the data region 400 and is consecutive in the time axis. In detail, the TCRS can be transmitted consecutively (i.e., at all symbols) or in a closely arranged manner in the time axis. The TCRS can be transmitted at a specific frequency region or in an extended manner in the frequency axis, as Figure 4 indicated.

[0088] Figure 5 is a diagram showing the positions of the DMRS and the TCRS proposed in the present application in the time-frequency domain. As described above, in order to quickly perform channel estimation in consideration of the low latency requirement of the 5G wireless communication, the DMRS, which is a reference signal for demodulation, is arranged at the beginning region of the subframe, as Figure 5 indicated, which is different from the case of Figure 3 However, it can be difficult to guarantee channel estimation performance in a low SNR region (-10 to 0 dB) only with the DMRS located at the beginning region of the subframe. This structure also has the disadvantage that it cannot track the channel variation in the time axis in a high mobility situation. This problem can be solved by channel tracking on the symbols to which the TCRS is mapped, as Figure 5 indicated. The TCRS can also be used for the purpose of compensating for phase noise in the 5G system operating in a high frequency band.

[0089] Although the TCRS occupies one subcarrier per 4 RBs in the frequency domain in Figure 5 according to Embodiment 1-1, the present application is not limited to such an arrangement, and it includes embodiments in which the TCRS is arranged at different positions in the frequency domain. For example, the TCRS can be mapped so as to repeat every X RBs (X ≥ 1), as Figure 5 indicated, or mapped to all subcarriers of the RBs located at a predetermined region in the frequency domain, as Figure 4 indicated. Although the TCRS is arranged to follow the DMRS in the time domain in Figure 5 , the present application is not limited to such an arrangement, and it includes embodiments in which the TCRS is arranged at different positions in the time domain. For example, the TCRS can be mapped to the OFDM symbols following the DMRS, as Figure 5 indicated, or to other OFDM symbols in the time domain if the 5G system is different from the LTE and LTE-A systems in the basic time-frequency resource structure. Assuming that an independent subframe (in which both a subframe scheduling data and ACK / NACK corresponding to the data) is used in the 5G system, if the last X (X ≥ 1) OFDM symbols of the subframe are used for uplink transmission, the corresponding region can not be used for TCRS transmission. If the TCRS overlaps with other reference signals, the TCRS can be preferentially configured.

[0090] Although Embodiment 1-1 relates to the structure and location of TCRS for downlink in time-frequency domain, if the 5G system also uses OFDMA in uplink, the structure and location of TCRS already described in Embodiment 1-1 can be identically used for downlink and uplink in time-frequency domain.

[0091] Embodiment 1-2

[0092] Embodiment 1-2 relates to a method for a base station to configure TCRS of a reference signal as proposed in the present invention. The TCRS can be configured commonly for all UEs within a cell (sector or transmission / reception point (TRP)) or configured on a UE basis (in a UE-specific manner). Configuring common TCRS is similar to configuring CRS in the LTE system to transmit a reference signal without applying any UE-specific precoding, and configuring UE-specific TCRS is similar to configuring DMRS in the LTE system to transmit a reference signal with applying UE-specific precoding. Since both TCRS operation methods have advantages and disadvantages, the present invention proposes both methods.

[0093] If common TCRS is configured, all UEs located within a cell (sector or TRP) can obtain additional information with a common reference signal, similar to the case where LTE CRS is used and channel tracking is performed based on TCRS. The additional information that can be obtained with the configuration of common TCRS can vary with the location of TCRS in time-frequency domain. For example, assuming that TCRS occupies one subcarrier per 4 RBs in the frequency domain at every subframe across the entire band, as shown in Figure 5 a UE can perform various measurements (e.g., radio resource measurement (RRM), Doppler spread measurement, and delay spread measurement) based on TCRS. Frequency offset can also be measured based on the characteristics of TCRS transmitted consecutively on the time axis as time elapses.

[0094] However, the common TCRS proposed in the present invention is different from the conventional LTE CRS in that TCRS overhead is less than CRS overhead. Unlike LTE CRS transmitted on every RB across the entire band, as shown in Figure 3 TCRS of a reference Figure 5 signal proposed in the present invention can be configured to be transmitted during a predetermined period of time without RRC configuration or dynamic signaling. The method for turning off the proposed TCRS configuration is described in detail later. However, the disadvantage of configuring common TCRS is that channel tracking performance on a UE-specific beamforming signal is degraded.

[0095] In case of configuring UE-specific TCRS, channel tracking can be performed more accurately on UE-specific beamforming signals compared to the case of configuring common TCRS. However, the UE-specific TCRS configuration has the following disadvantage: if orthogonal transmission layers are allocated to respective UEs in a multi-user (MU) transmission environment, resolution on a time axis (in this case, resolution can be interpreted as a ratio of resources of TCRS to overall resources) is reduced.

[0096] Figure 6 is a diagram illustrating a method for allocating transmission layers to UEs. Figure 6 The diagram 600 of illustrates that resolution of TCRS is reduced on a time axis in case of using time division multiplexing (TDM) as a multiplexing mode for allocating 4 transmission layers to respective UEs (among various multiplexing modes such as CDM and FDN). The diagram 610 illustrates that resolution of TCRS is reduced on a time axis in case of using CDM as a multiplexing mode for allocating 4 transmission layers to respective UEs. In order to overcome the disadvantage that resolution of TCRS is reduced when orthogonal transmission layers are allocated to respective UEs, a method of allocating TCRS in time series can be used on the assumption that phase drifts on all transmission layers are the same, as indicated by reference numeral 620. That is, the last method is to configure only one antenna port to TCRS.

[0097] In the foregoing, the advantages and disadvantages of the common TCRS and UE-specific TCRS configurations have been compared with each other. In the following, a method for configuring multiple TCRS and a function for turning off TCRS configuration as proposed in the present invention are described.

[0098] The multiple TCRS configuration method aims to minimize inter-cell (inter-sector or inter-TRP) interference. Different TCRSs can be configured to a UE using the multiple TCRS configuration method. Figure 7 A method for configuring 4 different TCRSs is illustrated by way of example. However, the multiple TCRS configuration method of the present invention is not limited to Figure 7 the exemplary case of. In detail, the multiple TCRS configuration method of the present invention can perform as follows.

[0099] Table 2 shows a method for configuring TCRS via high layer signaling such as RRC signaling. Here, TCRS-ConfigNZPId denotes a configuration value of TCRS, and maxTCRS-NZP TCRS (maxTCRS-NZP ≥ 0) can be configured. If TCRS-ConfigNZPId = 0, no TCRS is transmitted. Here, the UE can assume that data is transmitted in a TCRS region. If TCRS-ConfigNZPId ≠ 0, the TCRS-ConfigNZPId value indicates a transmission location of TCRS, and the UE can assume that a reference signal is transmitted at the corresponding TCRS location.

[0100] [Table 2]

[0101] -- ASN1START

[0102] TCRS-ConfigNZPId ::= INTEGER (0..maxTCRS-NZP)

[0103] -- ASN1STOP

[0104] Using the TCRS configuration method proposed in Embodiments 1-2 of the present application, a common TCRS or a UE-specific TCRS can be configured. Using a plurality of TCRS configuration methods and a function for turning off TCRS configuration, interference caused by a reference signal and the constant transmission of a reference signal can be minimized.

[0105] Embodiment 1-3

[0106] Embodiment 1-3 relates to UE operation based on the structure and configuration of TCRS, which is a reference signal proposed in the present application. In Embodiment 1-2, common TCRS and UE-specific TCRS configuration have been described. Hereinafter, corresponding UE operation with common TCRS and UE-specific TCRS configuration is described.

[0107] In the case of configuring a UE-specific TCRS, the TCRS can be transmitted only in a band of allocated resources, and the location at which the TCRS is transmitted is determined by the band of allocated resources. In LTE, a PRB bundling size configured for DMRS is determined according to a system bandwidth. In the present application, it is proposed that the bundling size of TCRS be determined as a multiple of the PRB bundling size configured for DMRS. One or more TCRSs can be allocated to PRBs in the bundling size of TCRS. In the case of configuring a UE-specific TCRS, the TCRS transmission start location can be determined in association with the start point of RBs allocated to the UE.

[0108] Figure 8 is a diagram showing exemplary TCRS allocation. In the case of configuring a UE-specific TCRS, referenceFigure 8 Figure 800 illustrates in detail the UE operation using TCRS. In Figure 800, it is assumed that UE-A is allocated 7 RBs, the PRB bundle size configured for DMRS is 4, and the bundle size applied to TCRS is 4, the same as the PRB bundle size. Assuming that the UE's TCRS transmission start position is configured every 4 RBs starting from the first RB in the allocated RBs, channel estimation is performed using the TCRS allocated within the bundle size applied to TCRS. Specifically, UE-A can perform channel estimation using TCRS A 810 included in 4 of the 7 RBs allocated to UE-A and TCRS B 810 included in the remaining 3 of the 7 RBs allocated to UE-A.

[0109] When configuring a public TCRS, TCRS can be transmitted across the entire band, and the TCRS transmission location is determined by the allocated band. In LTE, the PRB bundle size configured for DMRS is determined based on the system bandwidth. In this invention, it is proposed that the TCRS bundle size be determined as a multiple of the PRB bundle size configured for DMRS. One or more TCRS can be allocated to PRBs within the TCRS bundle size. When configuring a public TCRS, refer to... Figure 8 Figure 830 illustrates in detail the UE operation using TCRS. In Figure 830, it is assumed that the PRB bundle size configured for DMRS is 4, the bundle size applied to TCRS is 4, the same as the PRB bundle size, and TCRS is transmitted every 4 RBs across the entire bandwidth. The UE uses the TCRS allocated by the bundle size applied to TCRS to perform channel estimation. Specifically, the UE can use TCRS A840, which is allocated to UE-A for 3 RBs, to perform channel estimation.

[0110] In Examples 1-3, it is proposed that the bundle size applied to TCRS be determined as a multiple of the PRB bundle size configured for DMRS. It is also proposed that one or more TCRSs be allocated to PRBs within the TCRS bundle size. Setting the TCRS bundle size to be larger than the PRB bundle size configured for DMRS is advantageous for the UE to use more TCRSs to perform channel estimation, but disadvantageous in terms of generating scheduling constraints. Under the assumption of the method proposed in Examples 1-3, the UE can use TCRS to perform operations.

[0111] Figure 9 and Figure 10is a block diagram illustrating a configuration of a UE and a base station according to an embodiment of the present application. In order to accomplish the TCRS transmission / reception operation of the base station and the UE, which have been described in Embodiments 1-1 to 1-3, the receiver, the processor, and the transmitter of each of the base station and the UE should operate according to the corresponding embodiment.

[0112] Figure 9 is a block diagram illustrating a configuration of a UE according to an embodiment of the present application. As shown, the UE can include a processor 910, a receiver 900, and a transmitter 920. According to an embodiment of the present application, the receiver 900 and the transmitter 920 can be commonly referred to as a transceiver. The transceiver can transmit and receive a signal to and from a base station. The signal can include control information and data. The transceiver can include a radio frequency (RF) transmitter that up-converts and amplifies a signal to be transmitted and an RF receiver that low-noise-amplifies and down-converts a received signal. The transceiver can output a signal received through a radio channel to the processor 910 and transmit a signal output from the processor 910 through a radio channel. Figure 9

[0113] The controller 910 can control the overall operation of the UE according to the above-described embodiments of the present application. For example, the processor 910 can control the receiver 900 to receive a TCRS from a base station and interpret a TCR. The transmitter can also transmit a TCRS.

[0114] Figure 10 is a block diagram illustrating a configuration of a base station according to an embodiment of the present application. The base station can include a receiver 1000, a transmitter 1020, and a processor 1010. According to an embodiment of the present application, the receiver 1000 and the transmitter 1020 can be commonly referred to as a transceiver. The transceiver can transmit and receive a signal to and from a UE. The signal can include control information and data. The transceiver can include an RF transmitter that up-converts and amplifies a signal to be transmitted and an RF receiver that low-noise-amplifies and down-converts a received signal. The transceiver can output a signal received through a radio channel to the processor 1010 and transmit a signal output from the processor 1010 through a radio channel.

[0115] The controller 1010 can control the overall operation of the base station according to the above-described embodiments of the present application. For example, the processor 1010 can control to determine a TCRS transmission position in a time-frequency domain and generate TCRS configuration information to be transmitted to a UE. Thereafter, the transmitter 1020 transmits a TCRS and the configuration information to the UE, and the receiver 1000 receives a TCRS on a resource determined according to the configuration information.

[0116] ​According to an embodiment of the present application, the processor 1010 can control the base station to generate a radio resource control (RRC) signal including the TCRS configuration information. In this case, the RRC signal can indicate the TCRS configuration information.

[0117] The embodiments disclosed in the specification and drawings are presented to help explain and understand the present application, and are not intended to limit the scope of the present application. It will be obvious to those skilled in the art that changes and modifications can be made to the present application without departing from the spirit and scope of the present application. If necessary, the embodiments can be combined in whole or in part. For example, the base station and the UE can operate according to a combination of parts of Embodiments 1-1, 1-2, and 1-3 of the present application. Although the embodiments relate to the FDD LTE system, the present application can include alternative embodiments relating to other systems such as the TDD LTE and 5G NR system without departing from the technical spirit of the present application.

[0118] <Embodiment 2>

[0119] To meet various user requirements and quality of service in a 5th-generation (5G) cellular communication system or a new radio (NR) communication system, it is important to design a system capable of supporting different transmission / reception schemes and services. It is also important to design an NR system without potential system limitations that can limit services to be added in the future, taking into account forward compatibility. In addition, the use of dynamic time division duplex (TDD) is considered to improve the frequency utilization efficiency of the NR system compared to the conventional LTE system. Unlike the conventional LTE TDD system in which uplink subframes and downlink subframes are pre-configured to switch between uplink transmission and downlink transmission according to the configuration, the NR system is characterized in that a base station determines whether to use a subframe for uplink or downlink transmission through scheduling based on the distribution of UEs within a cell and the amount of transmission / reception data required. That is, switching between uplink and downlink is dynamically performed in units of subframes in a dynamic TDD mode.

[0120] Meanwhile, in order for the base station to control and manage UEs in an idle state within a cell, the base station must periodically transmit a broadcast channel including a synchronization signal and system information and reserve periodic uplink resources in order to be used for receiving an initial access request from a UE attempting to connect to the system. In the present application, the signal transmitted by the UE for the initial access request is referred to as a random access preamble, and the related operation is described in detail.

[0121] However, in a dynamic TDD characterized in that whether to use a subframe for uplink or downlink transmission is determined based on the distribution of UEs within a cell and the amount of transmission / reception data required to improve the frequency utilization efficiency, if a UE in an idle state must transmit and receive a periodic signal, this reduces the efficiency of the dynamic TDD.

[0122] Accordingly, the present application proposes a method and apparatus for performing a random access operation without degrading frequency utilization efficiency of dynamic TDD in an NR system supporting dynamic TDD.

[0123] An NR system aims to support a higher data rate than that of a conventional LTE system. In the NR system, it is considered to employ a method for transmitting a signal in a wide frequency band higher than 6 GHz to achieve such a high data rate. That is, it is considered to use a millimeter wave (mmWave) band such as a 28 GHz and 60 GHz band to increase a data rate. However, in order to compensate for high signal propagation loss in the mmWave frequency band, it is necessary to perform directional beam-based transmission using a plurality of antennas. In the case of using a directional beam-based transmission scheme, there is a problem in that it is difficult to transmit or receive a signal at a position where a beam is not formed. Although, for a case in which a UE is in a connected state, a base station can form an appropriate directional beam to the UE based on state information of the UE, if the UE is in an idle state, the base station can not be able to form a beam to the UE because it does not have state information of the UE. For example, if the base station can not be able to form a beam suitable for a UE attempting initial access in an idle state, it can not be able to receive a random access preamble transmitted by the UE.

[0124] Accordingly, the present application proposes a method and apparatus for performing directional beam-based random access in a frequency band higher than 6 GHz.

[0125] An NR system aims to support a higher data rate than that of a conventional LTE system. In the NR system, it is considered to employ a method for transmitting a signal in a wide frequency band higher than 6 GHz to achieve such a high data rate. That is, it is considered to use a millimeter wave (mmWave) band such as a 28 GHz and 60 GHz band to increase a data rate. However, in order to compensate for high signal propagation loss in the mmWave frequency band, it is necessary to perform directional beam-based transmission using a plurality of antennas. In the case of using a directional beam-based transmission scheme, there is a problem in that it is difficult to transmit or receive a signal at a position where a beam is not formed. Although, for a case in which a UE is in a connected state, a base station can form an appropriate directional beam to the UE based on state information of the UE, if the UE is in an idle state, the base station can not be able to form a beam to the UE because it does not have state information of the UE. For example, if the base station can not be able to form a beam suitable for a UE attempting initial access in an idle state, it can not be able to receive a random access preamble transmitted by the UE.

[0126] Accordingly, the present application proposes a method and apparatus for performing directional beam-based random access in a frequency band higher than 6 GHz.

[0127] Mobile communication systems have evolved into high-speed high-quality packet data communication systems capable of providing data and multimedia services in addition to early voice-oriented services (such as High Speed Packet Access (HSPA), LTE (or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), and LTE Pro defined in the 3rd Generation Partnership Project (3GPP); High Rate Packet Data (HRPD) and Ultra Mobile Broadband (UMB) defined in the 3rd Generation Partnership Project-2 (3GPP2); and 802.16e defined in IEEE).

[0128] An LTE system, which is one of representative broadband wireless communication systems, uses Orthogonal Frequency Division Multiplexing (OFDM) in a downlink (DL) and uses Single Carrier Frequency Division Multiple Access (SC-FDMA) in an uplink (UL). The term "uplink" refers to a radio link for transmitting data or control signals from a terminal interchangeably called a User Equipment (UE) and a Mobile Station (MS) to a radio link interchangeably called an Evolved Node B (eNB) base station (BS), and the term "downlink" refers to a radio link for transmitting data or control signals from a base station to a terminal. Such a multiple access scheme is characterized in that time-frequency resources for transmitting user-specific data and control information are allocated without overlapping each other, i.e., orthogonality is maintained in order to distinguish user-specific data and control information.

[0129] An NR system, which is a next-generation communication system, must satisfy a requirement for a data rate higher than that supported by conventional LTE, LTE-A, and LTE-Pro systems. For example, the NR system aims to increase a peak downlink data rate up to 20 Gbps and a peak uplink data rate up to 10 Gbps. The NR system also aims to increase a user-perceived data rate as well as a peak data rate.

[0130] In order to satisfy such a requirement, it is necessary to improve various signal transmission / reception techniques, including a Multiple Input Multiple Output (MIMO) transmission technique. In comparison with a conventional LTE system using a transmission bandwidth of up to 20 MHz in a band of 2 GHz, it is possible to satisfy the data rate requirement of the NR system by using a frequency bandwidth wider than 20 MHz in a frequency band of 3 to 6 GHz or higher than 6 GHz instead of the current LTE band of 2 GHz. Finally, in order to improve frequency utilization efficiency, dynamic TDD can be employed to adjust uplink and downlink transmission / reception time periods to adapt to the distribution of UEs within a cell and the amount of data required.

[0131] Dynamic TDD is a technique for switching between uplink transmission and downlink transmission in such a way that a base station determines whether to use a subframe as an uplink subframe or a downlink subframe based on the distribution of UEs within a cell and the amount of transmission / reception data required. In a conventional LTE system using a semi-static TDD operation, a subframe pattern of subframes designated for uplink and downlink is pre-configured to switch between uplink transmission and downlink transmission. Therefore, in the conventional LTE TDD system, it is difficult to adjust uplink / downlink occupancy time to adapt to changes in data traffic. Meanwhile, the above-described dynamic TDD is advantageous in maximizing frequency utilization efficiency by allowing a base station to dynamically perform switching between uplink and downlink to adapt to changes in data traffic within a cell.

[0132] Meanwhile, in order for a base station to control and manage UEs in an idle state within a cell, the base station must periodically transmit a broadcast channel including a synchronization signal and system information and receive an initial access request from a UE attempting to connect to the system. In the case of periodically transmitting a synchronization signal or a broadcast channel and receiving a random access preamble in a dynamic TDD mode, this can reduce the frequency utilization efficiency improvement expected by dynamic TDD. In the case of a base station periodically transmitting a synchronization signal and a broadcast channel to a UE in an idle state, a subframe carrying a synchronization signal and system information should always be fixed as a downlink subframe regardless of a data traffic state; similarly, in order for a base station to periodically receive a random access preamble transmitted by a UE in an idle state for initial access, it is necessary to fix a subframe arriving at a predetermined interval (period) as an uplink subframe. As such, if a specific subframe is fixed as an uplink or downlink subframe, this can cause a problem of reducing the frequency utilization efficiency of a base station.

[0133] Accordingly, the present application aims to provide a method and apparatus for efficiently performing a random access procedure for a UE in an idle state and improving frequency utilization efficiency in a communication system supporting dynamic TDD.

[0134] Figure 11 FIG. 1 is a signal flow diagram illustrating a random access procedure between a UE and a base station in a conventional LTE system to provide a basis for understanding the random access considered in the present application.

[0135] In Figure 11In the middle, at step 1120, the base station 1100 transmits a synchronization signal and a broadcast channel to be used by the UE 1110 in an idle or connected state to achieve synchronization and obtain system information within a cell. The UE 1110 can achieve time and frequency synchronization with the base station based on the synchronization signal transmitted by the base station, and detect a cell identifier of the base station. The synchronization signal can include a combination of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) used in LTE or an additional synchronization signal. The broadcast channel can be used to transmit system information necessary for connection to the base station and the cell. The system information can include information necessary for random access of the UE.

[0136] After receiving the synchronization signal and the broadcast channel, at step 1130, the UE 1110 can transmit a random access preamble to the base station 1100. In the conventional LTE system, the UE 1110 can transmit a random access preamble to the base station 1100 based on preamble information and frequency resource information obtained from the broadcast channel and a random access preamble transmission time. The random access preamble transmission time and the frequency resource information are allocated at a predetermined interval (period), and if it is determined to transmit a random access preamble, the UE can transmit the preamble on the random access preamble transmission resource occurring after the determination.

[0137] The base station attempts to detect a random access preamble transmitted by the UE on the random access preamble transmission resource that it has configured. In general, the random access preamble can be identified by time, frequency, and code; in the LTE system, the UE can be identified by a UE-specific code sequence. If the base station 1100 detects a random access preamble including a specific code sequence, at step 1140, the base station 1100 transmits a random access response to the corresponding UE in response to the preamble. The UE 1110 that has transmitted the random access preamble attempts to receive the random access response during a predetermined period of time after transmitting the random access preamble. The random access response can include resource allocation information, uplink timing control information, and uplink power control information to be used by the terminal that has transmitted the random access preamble to transmit uplink data.

[0138] After receiving the random access response, at step 1150, the UE 1110 can transmit Layer-2 and / or Layer-3 (L2 / L3) message information to the base station according to the uplink resource allocation information included in the random access response. The UE can use the information obtained from the random access response to transmit the L2 / L3 message information to the base station. After receiving the L2 / L3 message, at step 1160, the base station can transmit a collision resolution message in response to the L2 / L3 message. The collision resolution message is transmitted for resolving a collision that can occur in the random access procedure. That is, in the case where multiple UEs transmit random access preambles with the same code sequence at step 1130, they transmit L2 / L3 messages on the same uplink resource, which results in a collision. Accordingly, the collision resolution message transmitted at step 1160 is scrambled by a unique identifier included in a L2 / L3 message that is preferably received among the L2 / L3 messages transmitted by the multiple UEs, so that only the UE selected by the base station receives the collision resolution message.

[0139] As described with reference to Figure 11 , the synchronization signal and the broadcast channel are periodically transmitted by the base station, which can configure random access preamble transmission resources for the UEs at predetermined intervals (periods).

[0140] Figure 12 is a diagram illustrating a time-domain transmission resource structure considered in the NR system.

[0141] In Figure 12 , the time-domain transmission resource structure is composed of a transmission time interval (TTI) 1200. The fixed TTI is composed of a plurality of OFDM symbols. The TTI 1200 can include a downlink transmission period and an uplink transmission period. In detail, the downlink transmission period includes downlink control channel transmission periods 1212, 1242, and 1252 and downlink data channel transmission periods 1214, 1222, 1232, and 1244; and the uplink transmission period can include an uplink control channel transmission period 1248 and uplink data channel transmission periods 1256, 1264, and 1272. The TTI 1200 can further include guard periods (GPs) 1246, 1254, and 1262 for switching from the downlink to the uplink.

[0142] As Figure 12 indicated, the NR system can support transmission resource structures 1210, 1220, 1230, 1240, 1250, 1260, and 1270, the lengths of whose downlink control channels, downlink data channels, uplink control channels, and uplink data channels differ; each channel is composed of a plurality of OFDM symbols corresponding to a length of time.

[0143] Transmission resource structure 1210 can consist of downlink control channel 1212 and downlink data channel 1214. Transmission resource structure 1220 can consist only of downlink data channel 1212. Transmission resource structure 1230 can consist of downlink data channel 1232 and guard period 1234. Transmission resource structure 1240 can consist of downlink control channel 1242, downlink data channel 1244, guard period 1246, and uplink control channel 1248. Transmission resource structure 1250 can consist of downlink control channel 1252, guard period 1254, and uplink data channel 1256. Transmission resource structure 1260 can consist of guard period 1262 and uplink data channel 1264. Finally, transmission resource structure 1270 can consist only of uplink data channel 12.

[0144] Despite using Figure 12 The invention is described using the transmission resource structure depicted herein, but is not limited to this invention. Figure 12 It has a transmission resource structure, and it can be applied to various combinations of uplink and downlink channels.

[0145] NR systems can use references based on their duplex mode (e.g., FDD and TDD). Figure 12 The description refers to a combination of transmit resource structures. In FDD systems, this can be used on downlink frequencies. Figure 12 The transmission resource structures 1210 and 1220 are used on the uplink frequency. Figure 12 The transmission resource structures 1260 and 1270 are used. Meanwhile, in a TDD system, the following can be used: Figure 12 All transmission resource structures are depicted in the diagram. In the dynamic TDD considered in this invention, one of all transmission resource structures can be determined via subframes based on the data transmission / reception service to transmit or receive data.

[0146] Figure 13 This is a diagram illustrating a method for configuring random access preamble transmission resources for a base station used by a terminal in an LTE system.

[0147] exist Figure 13 In this context, time-frequency resource 1300 can be an uplink frequency resource in an FDD system or an uplink time resource in a TDD system. In the time-frequency resource, the horizontal axis 1320 represents time, and the vertical axis 1310 represents frequency. The base station can configure periodic preamble transmission resources 1330 on the time-frequency resource 1300 for use by the UE to transmit uplink signals. Therefore, the preamble transmission resource 1330 can appear at a predetermined interval (time period) 1340 on the uplink time-frequency resource 1300. The random access preamble transmission resource 1330 is configured as follows:Figure 13 The corresponding subframe should be configured as an uplink subframe in the case where the predetermined interval (period) 1340 or the predetermined subframe is always configured to include a random access preamble transmission resource.

[0148] In a conventional LTE FDD system in which uplink resources and downlink resources are separated in frequency, no problem occurs even if a specific subframe is configured to have a random access preamble transmission resource. Even in an LTE TDD system in which uplink subframes and downlink subframes are predetermined, no problem occurs if a random access preamble transmission resource is configured in an uplink subframe. In an NR system operating in dynamic TDD so as to allow a base station to dynamically switch between uplink subframes and downlink subframes according to uplink / downlink data traffic situations of UEs within a cell, it is difficult to pre-configure a specific subframe to be used in random access preamble transmission as described above.

[0149] In general, it is difficult for a base station to know how many UEs in an idle mode are present in a cell based on a random access preamble (a signal transmitted to a base station by an idle mode UE located within a cell in order to initially access a system). In this regard, configuring a specific subframe as a random access preamble transmission subframe can cause a problem of reducing frequency utilization efficiency regardless of data traffic situations. Therefore, there is a need for a method for efficiently configuring a random access preamble transmission resource.

[0150] It is also necessary to consider a beam for initial access of a UE in an NR system. As described above, it is considered to employ a method for transmitting a signal in a wide frequency band higher than 6 GHz in order to satisfy a requirement for increasing a data rate in an NR. In consideration of the fact that signal attenuation with distance in a frequency band higher than 6 GHz is greater than such attenuation in a frequency band lower than 6 GHz, a signal transmission / reception method based on a beam formed by a plurality of antennas is required to maintain coverage.

[0151] Figure 14 is a diagram illustrating an exemplary directional beam-based transmission considered in an NR system.

[0152] In Figure 14 , a base station 1400 managing a cell can perform communication with UEs 1410, 1420, and 1430 located within the cell. An area 1440 covered by the base station 1400 represents a maximum coverage range in which the base station 1400 can communicate with a UE using an omnidirectional beam. In the case of using an omnidirectional beam, as Figure 14 indicated, the coverage range can be reduced because propagation attenuation occurs compared to the case of using a directional beam. In the case of using a directional beam, as Figure 14In the example of FIG. 14, UEs 1410 and 1420 can perform omni-directional beam-based communication with base station 1400, but due to relatively high propagation attenuation, UE 1430 cannot perform omni-directional beam-based communication with base station 1400. In this case, the base station can use directional beam 1450 to increase its coverage for communication with UE 1430.

[0153] Due to its narrow beamwidth property compared to omni-directional beams, although the use of directional beams can increase coverage, it can result in communication failure if the beam direction between the UE and the base station is not accurately matched. In the example of FIG. 14, the beam formed toward UE 1430 does not point to UEs 1410 and 1420, and UEs 1410 and 1420 cannot communicate with base station 1400 using beam 1450. Figure 14

[0154] Since a UE in a connected state communicating with a base station transmitting a beam-based signal is able to transmit channel state information measured based on a reference signal transmitted by the base station to the base station, the base station can form an appropriate beam toward the corresponding UE for transmitting a signal. However, in the case where the UE is in an idle state without being connected to a base station within a cell, the UE has difficulty in transmitting channel state information to the base station and thus the base station is unable to form a beam toward the idle UE. In the above-described exemplary case, a problem can arise in that the coverage of a synchronization signal and a broadcast channel used by an idle UE to implement synchronization and initial access to a system and the coverage of a random access preamble transmitted by the UE for initial access are reduced.

[0155] To solve the above-described problem, in conventional systems, a beam sweeping technique has been considered, which is characterized in that a base station forms a beam for transmitting a synchronization signal and a broadcast channel, which changes in direction according to time to overcome beam direction mismatch. Recently, a method for a base station to form a beam, which changes in direction at a predetermined preamble transmission time interval for receiving a preamble transmitted by a UE, has also been considered.

[0156] Figure 15 is an illustration of an exemplary beam sweeping scheme for a base station to sweep a transmission beam in order to transmit a synchronization and broadcast channel in a downlink subframe.

[0157] As Figure 15 ​As illustrated, signals can be transmitted using beams 1550 to 1590 on multiple downlink subframes 1500 to 1540. Here, beams 1550 to 1590 are directional beams formed in predetermined directions. To address the problem that a UE located in a direction that does not match a beam direction cannot receive a signal in the case of using directional beams as described above, a base station can form beams that change direction according to subframes to cover all directions within a cell during multiple downlink subframes 1550 to 1590 in order to transmit signals. Figure 15 An exemplary case in which a base station forms beams that rotate in a clockwise direction by subframes during multiple consecutive downlink subframes to transmit synchronization signals and broadcast channels in all directions is depicted.

[0158] Figure 16 is a diagram of an exemplary beam sweeping scheme for a base station to sweep reception beams to receive random access preambles transmitted by UEs in uplink subframes.

[0159] As Figure 16 illustrated, signals can be received using beams 1650 to 1690 on multiple uplink subframes 1600 to 1640. Here, beams 1650 to 1690 are directional beams formed in predetermined directions. To address the problem that a base station cannot receive signals transmitted by a UE located in a direction that does not match a beam direction in the case of using directional beams as described above, the base station can form beams that change direction according to subframes to cover all directions within a cell during multiple uplink subframes 1650 to 1690 in order to receive signals. Figure 16 An exemplary case in which a base station forms beams that rotate in a clockwise direction by subframes during multiple consecutive uplink subframes to receive random access preambles is depicted.

[0160] The above describes a method for a base station to transmit synchronization signals and broadcast channels for idle UEs and to receive random access preambles in all directions. However, in the case of forming reception beams in a specific direction for receiving random access preambles in a specific subframe as described above, a problem of reduced frequency utilization can occur. In consideration of the complexity and implementation of a UE operating in a frequency band higher than 6 GHz, only one beam can be formed in a specific direction during a certain period. That is, it is preferable to have a transmission beam or a reception beam in one direction at a certain subframe because if the base station forms beams for transmitting to or receiving from UEs located in different directions, this can increase implementation complexity. In the case of a base station forming a beam in a specific direction for receiving random access preambles, if there is no user in the corresponding direction, a problem occurs in that it is difficult to schedule data of another UE on resources other than those for receiving random access preambles. This means that uplink frequency resources are wasted, resulting in reduced frequency utilization efficiency.

[0161] Accordingly, the present application proposes an efficient random access preamble transmission resource configuration method that can minimize frequency utilization efficiency deterioration caused by always fixing a specific subframe as an uplink subframe for receiving a random access preamble transmitted by an idle state UE in a dynamic TDD mode.

[0162] The present application also proposes an efficient random access preamble transmission resource configuration method that can minimize frequency utilization efficiency deterioration caused by always forming a specific reception beam at a specific subframe in a case where a base station performs reception beam sweeping to receive a random access preamble transmitted by a UE in order to support initial access of an idle state UE in a directional beam-based transmission / reception system.

[0163] The present application proposes an efficient random access preamble transmission resource configuration method that can minimize frequency utilization efficiency deterioration caused by always fixing a specific subframe as an uplink subframe for receiving a random access preamble transmitted by an idle state UE in a dynamic TDD mode.

[0164] The present application also proposes an efficient random access preamble transmission resource configuration method that can minimize frequency utilization efficiency deterioration caused by always forming a specific reception beam at a specific subframe in a case where a base station performs reception beam sweeping to receive a random access preamble transmitted by a UE in order to support initial access of an idle state UE in a directional beam-based transmission / reception system.

[0165] Figure 17 is a signal flow diagram illustrating a random access preamble transmission procedure of a terminal in an NR system according to an embodiment of the present application.

[0166] In Figure 17In the middle, the base station 1700 can periodically transmit a synchronization signal for the UE 1705 located within the cell at step 1710. The base station 1700 can transmit the synchronization signal using an omnidirectional beam or a directional beam. Although the base station generally prefers to transmit a synchronization beam using an omnidirectional beam in a frequency band below 6 GHz and using a directional beam in a frequency band above 6 GHz, the present application can be implemented regardless of the beam type for a specific frequency band. Considering the synchronization signal detection complexity of the UE and the base station operation, it is assumed that the base station transmits the synchronization signal in a fixed downlink subframe. In the case of transmitting the synchronization signal using a directional beam, it is assumed that the synchronization signal is transmitted using a directional beam formed in a specific direction at a specific downlink subframe. Considering that downlink data traffic is generally greater than uplink data traffic, it can be assumed that there is less degradation in frequency utilization efficiency in the case of transmitting a downlink synchronization signal using a fixed beam in a fixed subframe. The UE 1705 achieves time and frequency synchronization based on the synchronization signal transmitted by the base station 1700, and performs a cell search to obtain a cell identifier at step 1715.

[0167] The base station 1700 periodically transmits a broadcast signal to the UE 1705 located within the cell as a second step at step 1720. The base station 1700 can transmit the broadcast channel using an omnidirectional beam or a directional beam. Similar to the synchronization signal, the base station generally prefers to transmit a broadcast signal using an omnidirectional beam in a frequency band below 6 GHz and using a directional beam in a frequency band above 6 GHz. However, the present application can be implemented regardless of the type of beam for a specific frequency band. Since it is preferred to transmit a broadcast channel in the same manner as the synchronization signal, it is assumed that the base station transmits the broadcast channel in a fixed downlink subframe. In the case of transmitting the broadcast channel using a directional beam, it is also assumed that the broadcast channel is transmitted using a directional beam formed in a specific direction at a specific downlink subframe. The UE 1705 can receive the broadcast channel transmitted by the base station 1700 to acquire system information related to the NR system at step 1725.

[0168] The system information acquired by the UE 1705 can include information related to the random access operation of the UE. The system information related to random access can include information as follows.

[0169] - Random access preamble sequence information

[0170] - Random access preamble format

[0171] - Random access power control information

[0172] - Random access preamble transmission time and frequency resource information

[0173] Subsequently, UE 1705, which intends to perform initial access, determines the subframe and the random access preamble to be transmitted in the subframe based on the time and frequency resource information for random access preamble transmission obtained from the random access related information obtained from the broadcast information. At step 1735, UE 1705 receives control information on the downlink control channel in subframe 1730, which is configured to indicate random access preamble transmission resources.

[0174] If the control information received on the downlink control channel does not include a random access preamble transmission indicator (or there is no instruction to transmit it), then UE 1705 may not transmit the random access preamble in the corresponding subframe, even if the corresponding subframe is configured for the predetermined random access preamble transmission. Then, at step 1745, UE 1705 receives control information on the downlink control channel in the next subframe 1740, which is configured for random access preamble transmission. If the control information received on the downlink control channel includes a random access preamble transmission indicator or the corresponding indicator indicates that a preamble should be transmitted, then at step 1750, UE 1705 may transmit the random access preamble in the corresponding subframe. Here, the frequency resources used by the UE to transmit the random access preamble can be frequency resources pre-configured via system information.

[0175] Figure 17 The embodiments can be described in more detail below.

[0176] The following text is based on Figure 17 Method 1 is described. The subframe, pre-configured for random access preamble transmission, has a transmission resource structure capable of transmitting the downlink control channel. Figure 12 In the case of transmission resource structures 1240 and 1250, the base station can transmit an indicator on the downlink control channel used for random access preamble transmission operations, which instructs the UE to transmit a random access preamble. The UE attempts to detect the indicator indicating the transmission of the random access preamble in a subframe pre-configured for random access preamble transmission. If the UE detects the corresponding indicator indicating the transmission of the preamble on the downlink control channel, it can transmit the random access preamble according to the format configured on resource 1248 for the uplink control channel and resource 1256 for the uplink data channel included in the corresponding subframe.

[0177] If the time period for uplink control channel resource 1248 or uplink data channel resource 1256 is too short to transmit the random access preamble in the predetermined format, the UE may choose not to transmit the random access preamble. Based on... Figure 12In the case of a combination of the transmission resource structures of FIGS. 12 and 13, in which the uplink period is longer than one TTI 1200, the random access preamble can be transmitted in a longer format.

[0178] If the corresponding indicator is not detected on the downlink control channel, or if the detected indicator indicates that the preamble is not transmitted, the UE can not transmit the preamble in the corresponding subframe.

[0179] For the method 1, the downlink control channel can include a random access preamble transmission indicator, and in this case, the indicator can be transmitted in a separate structure or using a downlink control information transmission format using the downlink control channel in the common search space of the current LTE system.

[0180] Hereinafter, the method 2 is described. Figure 17 The method 2 is described. In the case of a combination of the transmission resource structures 1240 and 1250 of FIGS. 12 and 13, in which the uplink period is longer than one TTI 1200, the random access preamble can be transmitted in a longer format. Figure 12 The base station can transmit an indicator on the downlink control channel for the random access preamble transmission operation, the indicator indicating that the UE transmits the random access preamble. Here, the base station can additionally transmit a transmission timing field indicating that the UE transmits the random access preamble after a predetermined number of subframes after the current subframe. The UE attempts to detect the indicator indicating that the UE transmits the random access preamble in the subframe pre-configured for the random access preamble transmission and the transmission timing field. If the random access preamble transmission indicator indicates that the preamble is transmitted, the UE waits until the number of subframes indicated by the transmission timing field elapses from the end point of the corresponding subframe to transmit the random access preamble. For example, if the transmission timing field is set to a value indicating two subframes, the UE can transmit the random access preamble after two subframes after the end point of the subframe in which the corresponding downlink control channel is received.

[0181] If the time period of the uplink control channel resource 1248 or the uplink data channel resource 1256 is too short to transmit the random access preamble in a predetermined format, the UE can not transmit the random access preamble. In the case of a combination of the transmission resource structures of FIGS. 12 and 13, Figure 12 In the case of a combination of the transmission resource structures of FIGS. 12 and 13, in which the uplink period is longer than one TTI 1200, the random access preamble can be transmitted in a longer format.

[0182] If the corresponding indicator is not detected on the downlink control channel, or if the detected indicator indicates that the preamble is not transmitted, the UE can not transmit the preamble in the corresponding subframe.

[0183] For method 2, the downlink control channel may include an indicator indicating the transmission of a random access preamble and a transmission timing field indicating the subframe that can be used to transmit the random access preamble. In this case, the downlink control channel may be used in the common search space of the current LTE system to transmit the indicator and the transmission timing field in a separate structure or using the downlink control information transmission format.

[0184] The following text is based on Figure 17 Method 3 is described. The subframe, pre-configured for random access preamble transmission, has a transmission resource structure capable of transmitting the downlink control channel. Figure 12 In the case of transmission resource structures 1240 and 1250, the base station can transmit a transmission resource structure indicator on the corresponding downlink control channel to notify the UE of the transmission resource structure of the current subframe. The UE attempts to detect the transmission resource structure indicator indicating the transmission resource structure of the current subframe in a subframe pre-configured for random access preamble transmission. The transmission resource structure indicator can be an indication of... Figure 12 The indicator in the transmission resource structure depicted is used for the current subframe. If the UE detects the corresponding indicator on the downlink control channel, and if it determines based on the indicator that the corresponding subframe includes uplink control channel resource 1248 or uplink data channel resource 1256, then the UE can transmit the random access preamble in the format configured on the corresponding resource. If the time period of uplink control channel resource 1248 or uplink data channel resource 1256 is too short to transmit the random access preamble in the predetermined format, the UE may choose not to transmit the random access preamble.

[0185] If no corresponding indicator is detected on the downlink control channel, or if the detected indicator indicates that the corresponding subframe does not include uplink control channel resource 1248 or uplink data channel 1256, then the UE may not send a preamble in the corresponding subframe.

[0186] For method 3, the downlink control channel may include a transmission resource structure indicator for the corresponding subframe, and in this case, the downlink control channel may be used in the common search of the current LTE system to transmit the indicator in a separate structure or using the downlink control information transmission format.

[0187] The following text is based on Figure 17 Method 4 is described. The subframe pre-configured for random access preamble transmission has a transmission resource structure that can only transmit uplink channels. Figure 12In the case of the transmission resource structure 1260 and 1270 of FIG. 12, the UE can transmit the random access preamble in the corresponding subframe regardless of the reception of the downlink channel. In the case of the transmission resource structure of FIG. 13, the UE can transmit the random access preamble in the corresponding subframe regardless of the reception of the downlink channel. Figure 12 In the case of the combination of the transmission resource structure of FIG. 12 and 13, in which the uplink period is longer than one TTI 1200, the random access preamble can be transmitted in a longer format.

[0188] The methods 1, 2, 3, and 4 of the embodiment operate based on the fact that the system information for random access is transmitted in advance through the broadcast channel. That is, the present application proposes a method for the UE to transmit the random access preamble based on the indicator received on the downlink control channel in the subframe or the transmission resource structure of the corresponding subframe in the case where the time and frequency resources for transmitting the random access preamble are pre-configured in the system information for random access.

[0189] In the following embodiment, the UE operation method is described in the case where the random access preamble transmission time and frequency resource configuration is not included in the system information for random access.

[0190] Figure 18 is a signal flow diagram illustrating a random access preamble transmission procedure of a terminal in an NR system according to another embodiment of the present application.

[0191] In Figure 18 , the base station 1800 can periodically transmit a synchronization signal with respect to the UE 1810 located in the cell at step 1820. The base station 1800 can transmit the synchronization signal using an omnidirectional beam or a directional beam. Although the base station generally prefers to transmit a synchronization beam using an omnidirectional beam in a frequency band lower than 6 GHz and using a directional beam in a frequency band higher than 6 GHz, the present application can be implemented regardless of the beam type for a specific frequency band. In consideration of the synchronization signal detection complexity of the UE and the base station operation, it is assumed that the base station transmits the synchronization signal in a fixed downlink subframe. In the case of transmitting the synchronization signal using a directional beam, it is assumed that the synchronization signal is transmitted using a directional beam formed in a specific direction at a specific downlink subframe. In consideration of the fact that the downlink data traffic amount is generally greater than the uplink data traffic amount, it can be assumed that the frequency utilization efficiency is less degraded in the case where the downlink synchronization signal is transmitted using a fixed beam in a fixed subframe. The UE 1810 achieves time and frequency synchronization based on the synchronization signal transmitted by the base station 1800 and performs a cell search to obtain a cell identifier at step 1830.

[0192] At step 1840, the base station 1800 periodically transmits a broadcast signal to the UE 1810 located within the cell as a second step. The base station 1800 can transmit the broadcast channel using an omnidirectional beam or a directional beam. Similar to the synchronization signal, the base station generally prefers to transmit the broadcast signal with an omnidirectional beam in a frequency band below 6 GHz and with a directional beam in a frequency band above 6 GHz. However, the present application can be implemented regardless of the type of beam used for a specific frequency band. Since it is preferred to transmit the broadcast channel in the same manner as the synchronization signal, it is assumed that the base station transmits the broadcast channel in a fixed downlink subframe. In the case where the broadcast channel is transmitted using a directional beam, it is also assumed that the broadcast channel is transmitted using a directional beam formed in a specific direction at a specific downlink subframe. The UE 1810 can receive the broadcast channel transmitted by the base station 1800 to acquire system information related to the NR system at step 1850. The system information acquired by the UE 1810 can include information related to the random access operation of the UE. The random access related system information can include information as follows.

[0193] - Random access preamble sequence information

[0194] - Random access preamble format

[0195] - Random access power control information

[0196] Unlike the embodiment of Figure 17 , the random access related system information does not include time and frequency resource information for random access preamble transmission. That is, a subframe for transmitting a random access preamble is not configured. Thereafter, at step 1860, the UE 1810 that wants to perform initial access receives control information on a downlink control channel.

[0197] If the control information received on the downlink control channel does not include a random access preamble transmission indicator, or if the received indicator indicates that the preamble is not transmitted, the UE 1810 does not transmit a random access preamble. Thereafter, the UE 1810 receives control information on a downlink control channel in another subframe 1870. If the control information received on the downlink control channel includes a random access preamble transmission indicator or a corresponding indicator indicates that the preamble is transmitted, the UE 1810 can transmit a random access preamble in a corresponding subframe at step 1880.

[0198] Here, the frequency resource used by the UE to transmit the random access preamble can be a frequency resource pre-configured via system information. In the case where a frequency resource used to transmit the random access preamble is not configured in the system information, the base station can transmit random access preamble transmission frequency resource region information and a random access preamble transmission indicator on the downlink control channel. If the received downlink control information includes the random access preamble transmission indicator or a corresponding indicator indicates to transmit the preamble, the UE receives corresponding frequency resource information to transmit the random access preamble on the corresponding frequency resource.

[0199] Figure 18 Embodiments of the present application can be described in more detail as follows.

[0200] Hereinafter, the present application will be described in detail according to Figure 18 Method 5 is described below. The base station can transmit an indicator indicating the UE to transmit the random access preamble on all downlink control channels for the random access preamble transmission operation. The UE can detect the corresponding indicator on the downlink control channel, and if the corresponding indicator indicates to transmit the random access preamble, transmit the random access preamble according to a format configured on the uplink data channel resource 1256 or the uplink control channel resource 1248 included in the corresponding subframe. In this case, if the random access preamble transmission frequency resource is configured via the downlink control channel, the UE can transmit the random access preamble according to the configuration.

[0201] In the case where the time period of the uplink control channel resource 1248 or the uplink data channel resource 1256 is too short to transmit the random access preamble in the predetermined format, the UE can not transmit the random access preamble. In the case where the uplink period is longer than one TTI 1200 according to the combination of the transmission resource structures of Figure 12

[0202] If the corresponding indicator is not detected on the downlink control channel, or if the detected indicator indicates not to transmit the preamble, the UE can not transmit the preamble in the corresponding subframe.

[0203] For method 5, the downlink control channel can include the random access preamble transmission indicator, and in this case, the downlink control channel can be used in the common search space of the current LTE system in a separate structure or using the downlink control information transmission format to transmit the indicator.

[0204] Hereinafter, the present application will be described in detail according to Figure 18 ​Method 6 is described. The base station can transmit an indicator indicating the UE to transmit a random access preamble on all downlink control channels for a random access preamble transmission operation. Here, the base station can additionally transmit a transmission timing field indicating the UE to transmit a random access preamble after a predetermined number of subframes after the current subframe. If the random access preamble transmission indicator indicates to transmit a preamble, the UE transmits a random access preamble after waiting until the number of subframes indicated by the transmission timing field elapses from the end point of the corresponding subframe. For example, if the transmission timing field is set to a value indicating two subframes, the UE can transmit a random access preamble after two subframes after the end point of the subframe in which the corresponding downlink control channel is received. If a frequency resource for transmitting a random access preamble is configured via a downlink control channel, the UE can transmit a random access preamble according to the configuration.

[0205] If the time period of the uplink control channel resource 1248 or the uplink data channel resource 1256 is too short to transmit a random access preamble in a predetermined format, the UE can not transmit a random access preamble. In the case of the combination of the transmission resource structures according to Figure 12 the uplink period is longer than one TTI 1200, a random access preamble can be transmitted in a longer format.

[0206] If a corresponding indicator is not detected on a downlink control channel or if the detected indicator indicates not to transmit a preamble, the UE can not transmit a preamble in the corresponding subframe.

[0207] For method 6, the downlink control channel can include an indicator indicating to transmit a random access preamble and a transmission timing field indicating a subframe available for transmitting a random access preamble, and in this case, the indicator and the transmission timing field can be transmitted in a separate structure or using a downlink control information transmission format using a common search space of the current LTE system.

[0208] Hereinafter, method 7 is described according to Figure 18 Method 7 is described. The base station can transmit a transmission resource structure indicator informing an idle UE of a transmission resource structure of a current subframe on all downlink control channels for a random access preamble operation. The transmission resource structure indicator can be an indicator indicating Figure 12An indicator of one of the transmission resource structures depicted, for the current subframe. In the case where the UE detects the corresponding indicator on the downlink control channel, if it determines based on the corresponding indicator that the corresponding subframe includes the uplink control channel resource 1248 or the uplink data channel resource 1256, the UE can transmit the random access preamble in the format configured on the uplink control channel resource 1248 or the uplink data channel resource 1256. In this case, if the random access preamble transmission frequency resource is configured via the downlink control channel, the UE transmits the random access preamble according to the corresponding configuration.

[0209] In the case where the time period of the uplink control channel resource 1248 or the uplink data channel resource 1256 is too short to transmit the random access preamble in the predetermined format, the UE can not transmit the random access preamble. If the corresponding indicator is not detected on the downlink control channel, or if the detected indicator indicates that the corresponding subframe includes neither the uplink control channel resource 1248 nor the uplink data channel 1256, the UE can not transmit the preamble in the corresponding subframe.

[0210] For method 7, the downlink control channel can include a transmission resource structure indicator for the corresponding subframe, and in this case, the indicator can be transmitted in a separate structure or using a downlink control information transmission format using the downlink control channel in the common search of the current LTE system.

[0211] According to an embodiment of the present application, for the above-described methods 1 to 7, it can be considered that the base station uses a directional beam to communicate signals with the terminal. In this embodiment of the present application, the base station can further transmit directional beam information on the downlink channel for receiving an uplink signal in the corresponding subframe. In the present application, this information is referred to as uplink reception beam information, and the corresponding beam information can be indicated in the form of a specific number matching the beam direction. The uplink reception beam information indicates the direction of the beam used by the base station to receive a signal in an arbitrary subframe. The beam formed in the corresponding direction has a unique index, and the uplink reception beam information can indicate one of the indices.

[0212] The UE can determine a beam suitable for communication with the base station based on the downlink synchronization signal in the cell search process. That is, the UE already has information about the uplink reception beam suitable for being used by the base station to receive a signal transmitted by the UE. Accordingly, the UE can determine that the corresponding subframe is a subframe usable for transmitting a random access preamble according to one of methods 1 to 7, and transmit a random access preamble in the corresponding preamble if the uplink reception beam of the base station formed at the corresponding subframe matches the uplink reception beam predicted by the UE.

[0213] Figure 19 is a signal flow diagram illustrating a random access preamble transmission procedure between a base station and a UE communicating with each other using directional beams in an NR system according to an embodiment of the present application.

[0214] In Figure 19 , the base station 1900 can transmit a plurality of synchronization signals for the UE 1910 located within a cell at steps 1920 and 1930. The plurality of synchronization signals can be transmitted using different directional beams. For example, a synchronization signal 1920 is transmitted using a directional beam designated as a first beam, while a synchronization signal 1930 is transmitted using a directional beam designated as an n-th beam. At step 1940, the UE can complete cell search using a desired synchronization signal transmitted among the plurality of synchronization signals. After completing the cell search, the UE 1910 can extract information about a transmission beam and a reception beam of the base station suitable for communication with the base station. That is, the UE can estimate downlink transmission beam information and uplink reception beam information suitable for communication with the base station.

[0215] At step 1960, the UE receives a broadcast channel transmitted by the base station, and acquires system information from the broadcast channel at step 1950. As described above, the system information can include random access related information as described below.

[0216] - Random access preamble sequence information

[0217] - Random access preamble format

[0218] - Random access power control information

[0219] - Random access preamble transmission time and frequency resource information

[0220] Thereafter, at steps 1970 and 1980, the UE 1910 can receive uplink reception beam information of the base station via a downlink control channel transmitted by the base station, in addition to a random access preamble transmission indicator according to one of the above-described methods 1 to 7, a transmission resource structure or a transmission timing field of a corresponding subframe. The uplink reception beam information of the base station refers to information about a directional beam configured to be used by the base station to receive an uplink signal in a corresponding subframe.

[0221] If the information about the uplink reception beam of the base station configured via the downlink control channel matches the information about the reception beam of the base station estimated by the UE based on the synchronization signal, the UE can transmit a random access preamble in the corresponding subframe. If the uplink beam information received on the downlink control channel in the corresponding subframe does not match the estimated reception beam information of the base station, the UE can not transmit a random access preamble in the corresponding subframe.

[0222] The operation of configuring the random access resources of the UE in the NR system considered in this invention, and the UE transmitting a random access preamble according to the configuration, can be performed according to one of the methods 1 to 7 described above. Although not described in detail, the above operations can be performed according to any combination of methods 1 to 7 without departing from the scope of this invention.

[0223] Although the embodiments and methods of the present invention are primarily described in conjunction with dynamic TDD, the detailed description of the present invention can also be applied to other TDD and FDD systems.

[0224] Figure 20 and Figure 21 This is an illustration of a UE and a base station configured to implement an embodiment of the present invention. The UE and base station can operate according to the random access preamble transmission / reception method for NR systems proposed in the above embodiments.

[0225] Figure 20 This is a block diagram illustrating the configuration of a UE according to an embodiment of the present invention. Figure 20 As shown, the UE of the present invention may include an RF unit 2000, a random access preamble generator 2010, a synchronizer and cell searcher 2020, a broadcast channel receiver 2030, a controller 2040, and an antenna 2050.

[0226] RF unit 2000 converts baseband signals into transition band signals and sends the transition band signals to the antenna for transmission of corresponding signals via the antenna, or converts received signals received by the antenna into baseband signals and sends base station signals to synchronizer and cell searcher 2020. Synchronizer and cell searcher 2020 performs frequency and time synchronization and cell search based on synchronization signals sent by the base station. Broadcast channel receiver 2030 receives broadcast channels sent by the base station to obtain system information necessary for performing random access. If the UE needs to access a cell, random access preamble generator 2010 generates and sends a random access preamble. Controller 2040 controls RF unit 2000, random access preamble generator 2010, synchronizer and cell searcher 2020, broadcast channel receiver 2030, controller 2040, and antenna 2050, enabling the UE to perform synchronization and cell search, obtain system information, and send random access preambles.

[0227] Figure 21 This is a block diagram illustrating the configuration of a base station according to an embodiment of the present invention. Figure 21As shown, the base station can include an RF unit 2100, a synchronization signal transmitter 2110, a broadcast channel transmitter 2120, a random access preamble detector 2130, a controller 2140, and an antenna 2150. The RF unit 2100 converts a baseband signal into a transition band signal and transmits the transition band signal to the antenna in order to transmit a corresponding signal via the antenna, or converts a reception signal received by the antenna into a baseband signal and transmits the baseband signal to the random access preamble detector 2130. The synchronization signal transmitter 2110 transmits a synchronization signal to be used by the UE to achieve frequency and time synchronization based on the synchronization signal. The broadcast channel transmitter 2130 transmits a broadcast channel to be used by the UE to acquire system information. The random access preamble detector 2130 performs an operation for detecting a random access preamble transmitted by the UE. The controller 2140 can control the RF unit 2100, the synchronization signal transmitter 2110, the broadcast channel transmitter 2120, the random access preamble detector 2130, and the antenna 2150 so that the UE performs synchronization and cell search, system information acquisition, and random access preamble transmission.

[0228] The embodiments disclosed in the specification and drawings are presented to help explain and understand the present application, and are not intended to limit the scope of the present application. It will be obvious to those skilled in the art that changes can be made to the present application without departing from the spirit and scope of the present application. The embodiments can be combined in whole or in part, if necessary.

[0229] <Embodiment 3>

[0230] The present application relates to a wireless communication system, and particularly, to a data transmission / reception method and apparatus supporting a terminal capable of communicating data with at least one of different communication systems operating on exactly one or more carrier frequencies, and the terminal.

[0231] Mobile communication systems have been developed to provide voice communication services in a mobile state to users. Recently, mobile communication systems have evolved to support high-speed data communication services in addition to supporting early voice-oriented services. However, resource shortage of more high-speed services and increasing user demand are promoting evolution toward more advanced mobile communication systems.

[0232] As one of next-generation mobile communication standards for satisfying such requirements, Long Term Evolution (LTE) is being studied in the 3rd Generation Partnership Project (3GPP). LTE is a high-speed packet-based communication technology designed to provide up to 100 Mbps. In order to achieve this goal, various schemes are being discussed: one scheme to reduce the number of nodes located in a communication path by simplifying the configuration of a network; and another scheme to maximize a wireless protocol close to a wireless channel.

[0233] An LTE system employs a hybrid automatic repeat request (HARQ) scheme for physical layer retransmission when initial data transmission fails in decoding. The HARQ scheme is designed to operate in such a manner that a receiver transmits a negative acknowledgement (NACK) indicating decoding failure to a transmitter when it fails to decode data, so that the transmitter retransmits corresponding data on a physical layer. The receiver combines the retransmitted data with the data that failed in decoding to improve data reception performance. The HARQ scheme can also be designed to operate in such a manner that a receiver transmits an acknowledgement (ACK) indicating successful decoding to a transmitter when it succeeds in decoding data, so that the transmitter transmits new data.

[0234] Figure 22 is a basic time-frequency resource structure for transmitting downlink data or control channels in an LTE system.

[0235] In Figure 22 , the horizontal axis represents time, and the vertical axis represents frequency. The minimum transmission unit in the time domain is an OFDM symbol, and N symb OFDM symbols 2202 form a slot 2206, and 2 slots form a subframe 2205. Each slot spans 0.5 ms, and each subframe spans 1.0 ms. A radio frame 2214 is a time unit consisting of 10 subframes. In the frequency domain, the minimum transmission unit is a subcarrier, and the total system transmission bandwidth consists of N BW subcarriers 2204.

[0236] In the time-frequency resource structure, a basic resource unit is a resource element (RE) 2212 indicated by an OFDM symbol index and a subcarrier index. A resource block (RB) (or physical resource block (PRB)) 2208 is defined by N symb consecutive OFDM symbols 2202 in the time domain and N RB consecutive subcarriers 2210 in the frequency domain. That is, one RB 2208 consists of N symb x N RB REs 2212. Generally, an RB is the minimum data transmission unit. Generally, in an LTE system, N symb = 7, N RB = 12, and N BW and N RB are proportional to the system transmission bandwidth. The data rate increases in proportion to the number of RBs scheduled for a terminal.

[0237] Six transmission bandwidths are defined for the LTE system. In the case of an FDD system in which the downlink and the uplink are separated in frequency, the downlink transmission bandwidth and the uplink transmission bandwidth can be different from each other. The channel bandwidth indicates an RF bandwidth compared to the system transmission bandwidth. Table 3 shows the relationship between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system having a 10 MHz channel bandwidth uses a transmission bandwidth of 50 RBs.

[0238] [Table 3]

[0239]

[0240]

[0241] Downlink control information is transmitted in N OFDM symbols at the beginning of a subframe. Generally, N = {1, 2, 3}. Thus, at each subframe, the N value varies with the amount of control information to be transmitted. The control information includes a control channel transmission period indicator for indicating the number of OFDM symbols conveying control information, scheduling information for downlink or uplink data transmission, and a HARQ ACK / NACK signal.

[0242] In the LTE system, downlink or uplink data scheduling information is transmitted from a base station to a terminal using downlink control information (DCI). The uplink (UL) indicates a radio link for transmitting data or control signals from a terminal to a base station, and the downlink (DL) indicates a radio link for transmitting data or control signals from a base station to a terminal. The DCI is classified into different DCI formats according to purposes, for example, a UL grant indicating UL data scheduling or a DL grant indicating DL data scheduling, indicating the use of size-smaller control information, indicating whether to apply spatial multiplexing based on multiple antennas, and indicating the use of power control. For example, the DCI format 1 for the DL grant is configured to include at least one of the following information.

[0243] - Resource allocation Type 0 / 1 flag: The resource allocation Type 0 / 1 flag indicates whether the resource allocation scheme is Type 0 or Type 1. Type-0 is to allocate resources in units of resource block groups (RBGs) by applying a bitmap scheme. In the LTE system, the basic scheduling unit can be a resource block (RB) expressed with a time-frequency domain resource, and an RBG can include a plurality of RBs and can be the basic scheduling unit in the Type-0 scheme. Type-1 is to allocate specific RBs in an RBG.

[0244] - Resource block allocation: The resource block allocation indicates RBs allocated for data transmission. The resources can be determined according to the system bandwidth and the resource allocation scheme.

[0245] - Modulation and coding scheme (MCS): The MCS indicates a modulation scheme used for data transmission and a size of a transport block to be transmitted.

[0246] - HARQ process number: The HARQ process number indicates a process number of HARQ.

[0247] - New data indicator: The new data indicator indicates whether the HARQ transmission is an initial transmission or a retransmission.

[0248] - Redundancy version: The redundancy version indicates a redundancy version of HARQ.

[0249] - TPC command for PUCCH: The transmit power control (TPC) command for a physical uplink control channel (PUCCH) indicates a power control command for the PUCCH which is an uplink control channel.

[0250] After the channel coding and modulation process, the DCI can be transmitted on a physical downlink control channel (PDCCH) or an enhanced PDCCH (EPDCCH).

[0251] In general, the DCI can be independently channel-coded for each terminal, and the channel-coded DCI can be configured with a PDCCH related thereto and transmitted. In the time domain, the PDCCH can be mapped and transmitted during a control channel transmission period. The frequency domain mapping position of the PDCCH can be determined by the ID of each terminal, and it can be transmitted throughout the entire system transmission band.

[0252] Downlink data can be transmitted on a physical downlink shared channel (PDSCH) which is a physical channel for downlink data transmission. The PDSCH can be transmitted after the control channel transmission period, and scheduling information such as a detailed mapping position in the frequency domain and a modulation scheme can be indicated by the DCI transmitted on the PDCCH.

[0253] Using the 5-bit MCS in the control information constituting the DCI, the base station informs the terminal of a modulation scheme applied to the PDSCH to be transmitted and a data size (e.g., transport block size (TBS)) to be transmitted. The TBS corresponds to a size given before channel coding for error correction is applied to data (e.g., a transport block (TB)) to be transmitted by the base station.

[0254] The modulation schemes supported by the LTE system can include quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), and 64 QAM, and they have modulation orders (Qm) of 2, 4, and 6, respectively. That is, QPSK modulates 2 bits per symbol, 16 QAM modulates 4 bits per symbol, and 64 QAM modulates 6 bits per symbol.

[0255] In this embodiment, the PDCCH transmission can be understood as a control information transmission on the PDCCH, the PUCCH transmission as a control information transmission on the PUCCH, the PDSCH transmission as a data transmission on the PDSCH, and the PUSCH transmission as a data transmission on the PUSCH.

[0256] Compared with LTE Rel-8, 3GPP LTE Rel-10 adopts bandwidth expansion to accommodate more data traffic. This technique, called bandwidth expansion or carrier aggregation (CA), is able to increase the data rate as much as the expanded band compared with LTE Rel-8 that transmits data in a signal band. Each band is called a component carrier (CC), and the LTE Rel-8 terminal is configured to have a DL CC and an UL CC. The DL CC and the UL CC having a SIB-2 connection relationship are paired to be called a cell. The SIB-2 connection relationship between the DL CC and the UL CC is signaled by a terminal-specific signal. A UE supporting CA can receive DL data and transmit UL data through multiple serving cells.

[0257] In Rel-10, when it is difficult for a base station to transmit a physical downlink control channel (PDCCH) in a specific serving cell, the base station can transmit the PDCCH in another serving cell and configure a carrier indicator field (CIF) as a field to notify the PDCCH to indicate a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) of another serving cell. The CIF can be configured to a terminal supporting CA. The CIF is configured to indicate a serving cell by adding 3 bits to PDCCH information in a specific serving cell, and is included in the information only in the case of performing cross-carrier scheduling; if the CIF is not included, cross-carrier scheduling is not performed. The CIF is included in a DL assignment to indicate a serving cell in which a PDSCH scheduled by the DL assignment is transmitted, or in an UL grant to indicate a serving cell in which a PUSCH scheduled by the UL grant is transmitted.

[0258] As described above, LTE Rel-10 supports CA as a wideband extension technology, which makes it possible to configure multiple serving cells to a UE. The UE transmits channel information of the multiple serving cells in order to be used by the eNB for periodically or aperiodically scheduling data transmission. The eNB schedules data transmission per carrier, and the UE transmits ACK / NACK feedback corresponding to each-carrier data transmission. In LTE Rel-10, the UE is designed to transmit ACK / NACK with up to 21 bits, and if ACK / NACK feedback and channel information transmission overlap in one subframe, the UE prioritizes ACK / NACK feedback transmission and drops channel information. In LTE Rel-11, the UE is designed to transmit ACK / NACK feedback and channel information of one cell multiplexed with up to 22 bits on PUCCH format 3 resources using PUCCH format 3.

[0259] In LTE Rel-13 assuming a scenario for configuring up to 32 serving cells, the number of serving cells increases to 32 in addition to licensed bands. A technology for providing LTE service in an unlicensed band such as a 5 GHz band is introduced in consideration of a limitation in the number of licensed bands such as LTE frequencies, which is referred to as licensed assisted access (LAA). LAA makes it possible to use an LTE cell operating in a licensed band as a primary cell (PCell) and an LAA cell operating in an unlicensed band as a secondary cell (SCell). As in LTE, feedback information generated in an LAA cell (i.e., SCell) should be transmitted in a PCell, and the LAA cell can flexibly use uplink and downlink subframes. In the following description, unless otherwise specified, the term "LTE" is intended to include all advanced LTE technologies such as LTE-A and LAA.

[0260] As the next generation communication system after LTE, a new radio access technology (NR), i.e., a 5G wireless cellular communication system (hereinafter, 5G system) should be designed to meet services required by users and various requirements of service providers.

[0261] Accordingly, it is necessary to classify various 5G-oriented services into several types of services such as enhanced mobile broadband (eMBB) having various requirements such as a maximum data rate per UE of 30 Gbps, a maximum mobility per UE of 500 km / h, a maximum latency of 0.5 ms, and a maximum UE density of 1,000,000 UEs / km 2

[0262] ​For example, in the 5G system, eMBB aims to increase a peak data rate up to 20 Gbps in a DL and up to 10 Gbps in a UL per base station. At the same time, it aims to increase a user-perceived data rate. To meet such requirements, it is necessary to improve signal transmission / reception techniques, including a multiple input multiple output (MIMO) technique.

[0263] At the same time, mMTC is considered to support an application service for Internet of Things (IoT). To efficiently provide an IoT application service based on mMTC, it is necessary to secure a massive access resource for terminals within a cell, improve terminal coverage and battery life, and reduce device manufacturing costs. Considering that IoT terminals attached to various sensors and devices are used to provide a communication function, an IoT service should be designed to support a large number of terminals (e.g., 1,000,000 terminals / km 2 ) within a cell. Through the IoT service, an mMTC terminal can be located in a coverage hole such as a basement of a building, thereby requiring a wider coverage range than other services supported in the 5G communication system. An mMTC terminal, which is characterized by a low price and difficulty in replacing a battery, should be designed to have an extremely long battery life.

[0264] Finally, URLLC is a key mission type cellular-based communication service requiring ultra-low latency and ultra-high reliability, such as remote robots and machinery control, industrial automation, unmanned aerial vehicles, remote medical care, and emergency warning services. For example, the URLLC service requires a requirement of an air interface latency of less than 0.5 ms and a packet error rate equal to or less than 10 -5 In this regard, to support the URLLC service, the 5G system must support a transmission time interval (TTI) shorter than other services and allocate a wide range of resources in a frequency band.

[0265] The above-described services considered to be supported in the 5G communication system should be provided in a hybrid manner on one framework. That is, in terms of efficient resource management and control, it is preferable to manage and control services in an overall manner rather than individually managing and controlling services.

[0266] Figure 23 is a diagram illustrating an example of multiplexing services considered to be supported in the 5G system into the system.

[0267] In Figure 23 , a frequency-time resource 2300 for use in the 5G system can be defined by a frequency axis 2310 and a time axis 2320. In Figure 23In the depiction, eMBB 2340, mMTC 2350, and URLLC 2360 are managed on one frame, for example, in a 5G system. As an additional type of service considered to be supported in the 5G system, an enhanced mobile broadcast / multicast service (eMBMS) is used to provide a cellular-based broadcast service. The eMBB 2340, mMTC 2350, URLLC 2360, and eMBMS 2370 considered to be supported in the 5G system can be time division multiplexed (TDM) and / or frequency division multiplexed (FDM) in a system frequency bandwidth, and / or spatially division multiplexed.

[0268] For the eMBB 2340, it is preferable to occupy a frequency band as wide as possible during an arbitrary time period to guarantee an increased data rate as described above. Thus, although the eMBB service 2340 is preferably TDMed with other services in the system time-frequency resource 2300, the eMBB service can also be FDMed with other services in the system time-frequency resource 2300 if necessary.

[0269] For the mMTC 2350, unlike other services, it is necessary to increase a transmission period to guarantee a wide coverage, and the same packet can be repeatedly transmitted in the same transmission period to guarantee the coverage. A low complexity and a manufacturing price of a terminal affect a transmission bandwidth limitation. In consideration of such a requirement, the mMTC service 2350 is preferably FDMed with other services in the 5G system time-frequency resource 2300.

[0270] For the URLLC 2360, it is preferable to use a shorter TTI than other services to meet an ultra-low latency requirement. Also, to meet an ultra-high reliability requirement, it is preferable to guarantee a wide bandwidth in a frequency domain to implement a low coding rate. In consideration of such a requirement, the URLLC service 2360 is preferably TDMed with other services in the 5G system time-frequency resource 2300.

[0271] Different transmission / reception schemes and transmission / reception parameters can be provided to the above-described services to meet service-specific requirements. For example, different numerologies can be provided to the respective services to meet service-specific requirements. The term "numerology" is intended to include a cyclic prefix (CP) length, a subcarrier spacing, an OFDM symbol length, and a TTI in an OFDM or OFDMA-based communication system.

[0272] As an example of using a service-specific numerology scheme, a longer CP length than other services can be provided to eMBMS 2370. The feature of eMBMS 2370 is to transmit the same data within all cells because it is provided in a manner of broadcasting higher layer traffic. From the perspective of a terminal, if signals transmitted via multiple cells are received with a delay shorter than the CP length, the terminal is able to decode all the signals in order to achieve single frequency network (SFN) diversity, and this means that even a cell edge terminal can receive broadcast information without coverage limitations. However, CP overhead caused by supporting eMBMS 2370 with a longer CP length than other services in the 5G system results in resource waste, and this can be interpreted as a situation in which a longer OFDM symbol length than other services is required and at the same time a narrower subcarrier spacing than other services is required.

[0273] As another example of using a service-specific numerology scheme, a shorter TTI than other services can be provided to URLLC service 2360, thereby requiring an extremely short OFDM symbol length and a wider subcarrier spacing.

[0274] In the above, the services considered for support in the 5G system and the requirements for supporting the services have been described.

[0275] Meanwhile, in the 5G system, one slot can be defined as a slot consisting of 14 or 7 OFDM symbols. Accordingly, in the case of using a subcarrier spacing of 15 KHz, a slot spans 1 ms or 0.5 ms. In the 5G system, a TTI can also be defined as a mini-slot or a sub-slot, which consists of one or (the number of OFDM symbols constituting a slot - 1) slots for emergency transmission in an unlicensed band. In the case of a slot consisting of 14 OFDM symbols, the length of a mini-slot can be determined as one of 1 to 13 OFDM symbols. The length of a slot or a mini-slot can be configured as defined in the standard or notified to a UE via higher layer signaling or system information. Unlike a mini-slot or a sub-slot, the length of a slot can be determined as one of 1 to 14 OFDM symbols and notified to a UE via higher layer signaling or system information.

[0276] A slot or a mini-slot can be defined to have one of various transmission formats as follows.

[0277] - DL-only slot or full DL slot: A DL-only slot consists of only a DL period and is used for only downlink transmission.

[0278] - DL-centric slot: A DL-centric slot consists of a DL period, a GP, and a UL period, and is characterized in that the DL period is greater than the UL period in terms of the number of OFDM symbols.

[0279] - UL-centric slot: A UL-centric slot consists of a DL period, a GP, and a UL period, and is characterized in that the UL period is longer than the DL period in terms of the number of OFDM symbols.

[0280] - UL-only slot or full-UL slot: A UL-only slot consists of only a UL period and is used only for uplink transmission.

[0281] Although the above classification of the slot format has been made, the mini-slot format can also be classified. That is, a mini-slot can fall into one of the following categories: DL-only mini-slot, DL-centric mini-slot, UL-centric mini-slot, and UL-only mini-slot.

[0282] It is considered that the 5G system operates on frequencies of several GHz to several tens of GHz, and in a relatively low frequency band of several GHz, FDD is preferred over TDD, while in a relatively high frequency band of several tens of GHz, TDD is preferred over FDD. However, unlike FDD, which is characterized in that UL and DL resources are invariant due to UL and DL frequency separation, TDD is characterized in that UL and DL share the same frequency, so that UL or DL resources become available at the same time. It can be difficult to meet the low latency requirement of URLLC because of the time delay before UL or DL resources become available, assuming that URLLC transmission is required in UL or DL. Therefore, in order to meet the low latency requirement of URLLC in the TDD mode, a method of dynamically switching between UL and DL according to the transmission direction (i.e., UL or DL) of URLLC data is required.

[0283] An important requirement of the 5G system is to be designed to support 5G phase 2 or beyond 5G services and technologies without causing backward compatibility problems with conventional 5G technologies, even when 5G phase 2 or beyond 5G services and technologies are multiplexed in the 5G operating band. Such a requirement is referred to as forward compatibility, which should be considered when the 5G system is initially designed for technologies that can be supplied in the future.

[0284] The lack of consideration of forward compatibility in the initial LTE standardization phase has limited the support of new services within the LTE framework. For example, the limitation of LTE Release-13, which introduced eMTC, is that a terminal can only operate in a frequency band of 1.4 Mhz regardless of the system bandwidth of a serving cell, in order to reduce complexity and terminal manufacturing costs. This means that a terminal supporting eMTC can not be able to receive a physical downlink control channel (PDCCH) transmitted over the entire system bandwidth of a conventional system, resulting in a limitation on signal reception during a PDCCH transmission time interval.

[0285] In this regard, the 5G communication system should be designed to consider coexistence between operations of services to be considered for provisioning and services supported in the 5G communication system. It can also be necessary to design the 5G communication system to support forward compatibility so that services to be considered for provisioning in the future are freely allocated transmission resources in a time-frequency resource domain supported by the 5G communication system. Therefore, a method of freely allocating time-frequency resources to support forward compatibility in the 5G system is required.

[0286] Exemplary embodiments of the present application are described in detail with reference to the accompanying drawings. The same reference numbers are used throughout the drawings to refer to the same or like parts. Detailed descriptions of well-known functions and structures incorporated herein can be omitted to avoid obscuring the subject matter of the present application.

[0287] Although the description and embodiments of the present application relate to LTE and 5G systems, those skilled in the art will understand that the present application can be equally applied to other communication systems having similar technical backgrounds and channel formats with slight modifications without departing from the spirit and scope of the present application.

[0288] Hereinafter, a 5G communication system in which a 5G cell operates in a standalone mode, and a 5G communication system in which a 5G cell operates in a non-standalone mode in combination with other standalone 5G cells via dual connectivity or carrier aggregation are described.

[0289] Figure 24 and Figure 25 are diagrams showing communication systems according to embodiments 3-1 and 3-2 of the present application. The method proposed in the present application can be applied to both of the systems of Figure 24 and Figure 25 .

[0290] Figure 24 Part (a) of FIG. 21 depicts a case in which a 5G cell 2410 operating in a standalone mode is hosted by a base station 2400 in a network. A UE 2420 is a 5G-capable UE having a 5G communication module. The UE 2420 achieves synchronization based on a synchronization signal transmitted by the standalone cell 2410, receives system information, and attempts to randomly access the 5G base station 2400. The UE 2420 establishes an RRC connection with the 5G base station 2400 and transmits data with the base station via the 5G cell 2410. In this case, the duplex mode of the 5G cell 2410 is not limited, and a plurality of serving cells can be provided to the 5G cell.

[0291] Figure 24Part (b) of FIG. 23 depicts a case in which a 5G standalone base station 2430 and a 5G non-standalone base station 2440 are deployed for improvement of data rates. A UE 2460 is a 5G-capable UE having a 5G communication module for performing 5G communication with a plurality of base stations. The UE 2460 achieves synchronization based on a synchronization signal transmitted via the 5G standalone base station 2430, receives system information, and attempts random access to the 5G standalone base station 2430. The UE 2460 establishes an RRC connection with the 5G standalone base station 2430, additionally configures a 5G non-standalone cell 2470, and transmits data with the 5G standalone base station 2430 or the 5G non-standalone base station 2440.

[0292] In this case, the duplex mode of the 5G standalone base station 2430 and the 5G non-standalone base station 2440 is not limited, and it is assumed that the 5G standalone base station 2430 and the 5G non-standalone base station 2440 are connected to each other through an ideal backhaul network or a non-ideal backhaul network. The ideal backhaul network 2450 supports fast X2 communication between base stations. A plurality of 5G cells can be configured.

[0293] Figure 25 Part (a) of FIG. 23 depicts a case in which an LTE cell 2510 and a 5G cell 2520 are hosted by a base station 2500 in a network. A UE 2530 can be an LTE-capable UE having an LTE communication module or a 5G-capable UE having a 5G communication module. The UE 2530 achieves synchronization based on a synchronization signal transmitted via the LTE cell 2510 or the 5G cell 2520, receives system information, and transmits data with the base station 2500 via the LTE cell 2510 or the 5G cell 2520. In this case, the duplex mode of the LTE cell 2510 and the 5G cell 2520 is not limited. If the LTE cell is a PCell, uplink control information is transmitted via the LTE cell 2510; if the 5G cell is a PCell, uplink control information is transmitted via the 5G cell 2520. A total of up to 32 LTE and 5G cells can be configured.

[0294] In the above-described exemplary network, it is assumed that the base station 2500 is equipped with an LTE communication module (system) and a 5G communication module (system) to support both the LTE and 5G systems in real time. In the case of partitioning the time resources of the LTE and 5G systems, the base station can dynamically allocate the time resources of the LTE and 5G systems. The UE 2530 can receive a signal indicating allocation of resources (time resources, frequency resources, antenna resources, spatial resources, etc.) of the LTE and 5G cells in order to identify resources for transmitting data via the LTE cell 2510 and the 5G cell 2520 based on the received signal.

[0295] Figure 25Part (b) of FIG. 25 illustrates a case in which an LTE macro base station 2540 for securing wide coverage and a 5G small base station 2550 for increasing data transmission amount are deployed. A UE 2570 can be an LTE-supporting UE having an LTE communication module, a 5G-supporting UE having a 5G communication module, or a UE equipped with both an LTE communication module and a 5G communication module. The UE 2570 achieves synchronization based on a synchronization signal transmitted by the LTE base station 2540 or the 5G base station 2550, receives system information, and transmits data via the LTE base station 2540 and the 5G base station 2550. In this case, the duplex mode of the LTE macro base station 2540 and the 5G small base station 2550 is not limited. If the LTE cell is a PCell, uplink control information is transmitted via the LTE cell 2590; if the 5G cell is a PCell, uplink control information is transmitted via the 5G cell 2580. Here, it is assumed that the LTE base station 2540 and the 5G base station 2550 are connected to each other through an ideal backhaul network or a non-ideal backhaul network. In the case of connection through an ideal backhaul network 2560 supporting fast X2 communication, the 5G base station 2550 can receive relevant control information from the LTE base station 2540 in real time via X2 communication although only uplink transmission is performed to the LTE base station 2540. A total of up to 32 LTE and 5G serving cells can be configured.

[0296] The base station 2540 or 2550 can support an LTE system and a 5G system in real time. For example, if one of the base stations (e.g., the base station 2540) divides time resources into LTE system time resources and 5G system time resources, it can dynamically configure the LTE system time resources and the 5G system time resources and transmit a signal indicating the configuration to the other base station (e.g., the base station 2550) via X2 communication. The UE 2570 can receive a signal indicating allocation of resources (time resources, frequency resources, antenna resources, spatial resources, etc.) of LTE and 5G cells from the LTE base station 2540 or the 5G base station 2550 in order to identify resources for transmitting data via the LTE cell 2590 and the 5G cell 2580.

[0297] Meanwhile, in the case of connection through a non-ideal backhaul network 2560, it is not possible for the base station to communicate via X2 communication. In this case, the base station 2540 or 2550 can semi-statically support the LTE and 5G systems. For example, if one of the base stations (e.g., the base station 2540) divides time resources into LTE system time resources and 5G system time resources, it can dynamically configure the LTE system time resources and the 5G system time resources and, in advance, transmit a signal indicating the configuration to the other base station (e.g., the base station 2550) via X2 communication for distinguishing the resources of the LTE and 5G systems. The terminal 2570 can receive a signal indicating an allocation of resources (time resources, frequency resources, antenna resources, spatial resources, etc.) of the LTE and 5G cells from the LTE base station 2540 or the 5G base station 2550 in order to identify resources for transmitting data via the LTE cell 2590 and the 5G cell 2580.

[0298] Figure 26 is a diagram showing a situation of a problem to be solved by the present application. Referring to parts (a) and (b) of Figure 26 are described when a UE is not aware of when time-frequency resources freely allocated for supporting forward compatibility in a 5G system are configured via a base station implementation.

[0299] In Figure 26 part (a) of, time-frequency resources 2600 for use by a 5G system are depicted along a frequency axis 2605 and a time axis 2610. Part (a) depicts a situation in which mMTC resources 2615 and forward compatibility resources (FCRs) 2620 are managed by a 5G base station in a framework of a 5G system. The FCRs 2620 can be referred to by different names, such as compatibility guarantee resources and compatibility assurance resources. The FCRs can also be referred to by another name, such as a blank resource, a reserved resource, and an unknown resource. The FCRs refer to resources that are guaranteed in advance in time-frequency resources used by a 5G system for forward compatibility, LTE-5G system coexistence, and other purposes (e.g., configuring URLLC resources to have FCRs when multiplexing URLLC, because eMBB does not need to know the multiplexing of URLLC). In the present application, all resources for the above-described purposes are referred to as FCRs.

[0300] As described above, mMTC 2620 is different from other services in that a long TTI is required to guarantee wide coverage and to guarantee coverage by repeatedly transmitting the same packet during the TTI. Thus, in the case where FCR 2620 is configured via a base station implementation without the UE's awareness, FCR 2620 and mMTC resources 2615 can collide with each other and thus the UE cannot receive the repeatedly transmitted data. Thus, there is a need to define a signaling operation for informing the UE of the FCR region 2620 so that the UE operates properly, even when the FCR region collides with other 5G service resource regions.

[0301] In the above case, the UE can perform a rate matching or puncturing operation on the 5G service transmission resource colliding with the FCR region. Rate matching is an operation of mapping data to the 5G service transmission resource remaining after excluding the portion of the 5G service transmission resource colliding with the FCR region at the transmitter (in this case, the transmitter can be a base station) and performing transmission and reception of the mapped data at the transmitter and the receiver (in this case, the receiver can be a UE); and puncturing is an operation of performing data decoding at the receiver (in this case, the receiver can be a UE), although assuming that 5G service data is also mapped to the portion of the 5G service transmission resource colliding with the FCR region, taking into account the reception value at the 5G service resource not colliding with the FCR region (or processing the reception value on the 5G service transmission resource not colliding with the FCR region as 0).

[0302] The base station can transmit a signal indicating that a rate matching or puncturing operation is performed via a higher layer or a physical signal, and the UE can perform a rate matching or puncturing operation with respect to 5G service data on a resource region colliding with the FCR. The UE can perform a rate matching or puncturing operation as predetermined according to a 5G transmission signal. That is, in the case where the FCR and the reference signal resource collide with each other, the reference signal in the collision region can be punctured; in the case where the FCR and the 5G downlink control channel transmission region collide with each other, a rate matching operation can be performed on the 5G downlink control channel transmission in the collision region.

[0303] In Figure 26 In part (b), a frequency-time resource 2650 used by a 5G system is depicted along a frequency axis 2655 and a time axis 2660. Part (b) depicts a case in which a channel state reference signal resource 2665 for channel state information measurement and an FCR 2670 are managed by a 5G base station in the framework of a 5G system.

[0304] A channel state reference signal can be transmitted by a base station across a wide frequency band on a channel state reference signal resource 2665. The frequency band of the channel state reference signal can be pre-configured via higher layer signaling, and a UE performs a measurement on the channel state reference signal resource 2665 to generate channel state information, which is fed back to the base station. Thus, if FCR 2670 is configured via a base station implementation without the UE's awareness, FCR 2670 can collide with the channel state reference signal resource 2665 with each other, and the UE performs a measurement on the channel state reference signal resource 2665 and generates incorrect channel state information without the awareness that the channel state reference signal resource 2665 is occupied by the FCR, which is fed back to the base station. Thus, there is a need for a signaling operation to limit an area for informing the UE of the FCR 2670 so that the UE operates properly even when a reference signal of another 5G service collides with the FCR 2670 with each other.

[0305] Next, a signaling for indicating an area of an FCR proposed in the present disclosure is described.

[0306] The signaling for indicating an FCR area can include at least time area information or frequency area information. Specifically, a downlink frequency area and a time area and an uplink frequency area and a time area can be defined separately. A time area of an FCR can consist of one or more slots, a slot being a unit of time used by an eMBB UE to transmit / receive data. For a case of using a subcarrier spacing equal to or less than 60 KHz, a slot can consist of 7 or 14 OFDM symbols, and can be configured via higher layer signaling during 7 or 14 OFDM symbols. For a case of using a subcarrier spacing greater than 60 KHz, a slot can consist of 14 OFDM symbols. A time area of an FCR can consist of one or more mini-slots or sub-slots, a mini-slot being a unit of time used by a URLLC UE to transmit / receive data. A mini-slot or a sub-slot can consist of a number of OFDM symbols less than 7. A time area of an FCR can consist of some OFDM symbols less than the number of OFDM symbols constituting a slot or a mini-slot. An uplink or downlink frequency area of an FCR corresponds to a unit of a physical resource block (PRB) consisting of 12 subcarriers or a unit of a sub-band consisting of at least one PRB. A frequency area of an FRC can also consist of some subcarriers less than the number of subcarriers constituting a PRB.

[0307] The FCR zone indication signaling can refer to the actual use of the FCR by the base station, and the FCR zone indication signaling and signaling for indicating whether the FCR is actually used by the base station can be separately signaled. The FCR zone indication signaling and signaling for indicating whether the FCR is actually used by the base station can be signaled using a UE-specific signal, a service-specific signal (e.g., a signal for causing the UE to receive eMBB, URLLC, or mMTC), a cell-common signal (as a master information block (MIB) of system information), a system information block (SIB), or a 5G release-specific signal. In the case where the UE collides with the 5G service zone or the 5G signal collides with the FCR, the FCR zone indication signaling can be signaled using a signal indicating that a rate matching or puncturing operation is performed.

[0308] The FCR zone indication signaling or signaling for indicating whether the FCR is actually used by the base station can be signaled from the base station to the UE using a higher layer signal or a physical signal, and the UE can acquire the signal to determine the FCR zone and whether the FCR zone is actually used by the base station, and if the FCR zone collides with the 5G service zone or the 5G signal, perform an appropriate predefined procedure.

[0309] In more detail, in the case where the base station configures a plurality of FCRs, the configuration information can be transmitted to the UE via a higher layer signal, and the base station can inform the UE of the FCR among the plurality of FCRs that is recommended to be actually used in the current situation via a physical signal. The UE can receive the plurality of FCR configuration information (a bit signal indicating a frequency zone or a time zone, FCR repetition interval (period) information or offset, and priority) via a higher layer signal and information on the enabled FCR among the plurality of FCRs via a physical signal (a common downlink control channel or a dedicated downlink control channel). The UE can determine that the FCR is enabled while being configured via a higher layer signal. If the FCR informed to the UE has different priorities, the UE can stop transmitting / receiving all 5G channels and signals on the FCR with the highest priority and perform transmission / reception of a specific 5G channel or signal predetermined in the standard or indicated via a higher layer signal on the FCR with the lowest priority. For example, the base station can indicate to the UE to transmit / receive a specific 5G channel or signal causing interference on the FCR with a lower priority via the above-described signal, and the UE can transmit / receive the 5G channel or signal after receiving the above-described signal. The UE assumes that the other FCRs are disabled based on the information on the enabled FCR, and if the enabled FCR collides with data reception or reference signal reception of the UE, operates according to the method proposed in the present invention. If the disabled FCR collides with data reception or reference signal reception of the UE, the UE normally receives data and a reference signal while ignoring the disabled FCR although the disabled FCR overlaps with a data resource or a reference signal resource (assuming that the FCR is not configured).

[0310] The high layer signal for configuring the plurality of FCRs can include bit information indicating whether each FCE is enabled or disabled, the base station transmits the enabling / disabling information and the FCR configuration information to the UE via the high layer signal; and the UE receives the high layer signal, and if the enabled FCRs collide with data reception or reference signal reception of the UE, operates according to the method proposed in the present disclosure. If the disabled FCRs collide with each other in data reception or reference signal reception of the UE, the UE normally receives data and reference signals while ignoring the disabled FCRs although the disabled FCRs overlap with data resources or reference signal resources (assuming that the FCR is not configured).

[0311] The bit information indicating whether the FCR including one or more time regions (subframe, slot, or mini-slot or sub-slot) and frequency regions (subband, PRB, or subcarrier) is configured / deconfigured or enabled / disabled can be transmitted via a physical signal (common downlink control channel or dedicated downlink control channel) or a high layer signal. Specifically, the FCR can be selected among time and frequency resources to be used by the UE to receive a downlink control channel. The base station can transmit information indicating that a specific time or frequency region or a combination of time and frequency regions is enabled / disabled to the UE via a physical signal or a high layer signal, and the UE receives the corresponding signal to attempt to decode the downlink control channel only on the deconfigured or disabled FCR and not on the configured or enabled FCR, thereby saving the transmission power of the UE.

[0312] The bit information indicating whether the FCR including one or more time regions (subframe, slot, or mini-slot or sub-slot) and frequency regions (subband, PRB, or subcarrier) is configured / deconfigured or enabled / disabled can also be transmitted via a physical layer signal (common downlink control channel or dedicated downlink control channel). Specifically, the FCR can be selected among time and frequency resources to be used by the UE to perform downlink control channel measurement. The base station can transmit information indicating whether a specific frequency region is configured or enabled / disabled to the UE via a physical signal or a high layer signal. The UE receives the FCR signal to verify the validity of the time or frequency region included in the deconfigured or disabled FCR for downlink channel measurement, and then attempts the downlink channel measurement. The UE receives the FCR signal to verify the invalidity of the time or frequency region included in the deconfigured or disabled FCR for downlink channel measurement, and then skips the downlink channel measurement on the corresponding region, thereby saving the transmission power of the UE.

[0313] Next, referring to Figure 27 A method proposed to solve the situation in which the FCR region collides with the 5G service region each other according to Embodiment 3-1 of the present disclosure is described.

[0314] Figure 27 is a diagram illustrating Embodiment 2-1 of the present application.

[0315] In Figure 27 , a frequency-time resource 2700 used by a 5G system is depicted along a frequency axis 2710 and a time axis 2720. Figure 27 A case in which eMBB 2730 and 2740 and FCR 2750 are managed by a 5G base station in a framework of a 5G system is depicted. Although the drawing depicts an exemplary case in which FCR and eMBB resource 2740 collide with each other, the present embodiment also applies to a case in which FCR collides with 5G service resources such as mMTC, URLLC, and eMBMS resources in addition to eMBB.

[0316] The FCR region indication signaling can include a signal indicating that the UE performs a rate matching or puncturing operation in a case in which FCR collides with a 5G service region or a 5G signal.

[0317] As described above, the rate matching or puncturing operation can be performed as predetermined according to a 5G transmission signal. In a case in which the location of the FCR region and whether FCR is actually used are signaled to the UE, if the FCR 2750 and a resource region in which eMBB data transmission / reception is scheduled collide with each other, the UE prioritizes transmission on the FCR 2750 and thus does not map eMBB data to a resource colliding with the region of the FCR 2750 in the region in which eMBB data is scheduled. That is, if the UE determines to perform rate matching for eMBB data and a reference signal for demodulation of data overlaps with the FCR region, the UE attempts data transmission / reception assuming that eMBB data is transmitted / received on eMBB data resources without overlapping with a resource element corresponding to the overlapping region. The UE can not perform rate matching or puncturing for eMBB data and schedule a reference signal for demodulating data on a resource overlapping with the region of the FCR 2750 in a resource region in which eMBB data transmission is scheduled according to a signal indicating to perform a rate matching or puncturing operation.

[0318] Next, the operation of a base station and a UE in a case in which an FCR region collides with a 5G service region is described with reference to FIG. 28.

[0319] Figure 28a and Figure 28b is a flowchart illustrating the operation of a base station and a UE according to Embodiment 3-1 of the present application.

[0320] First, the operation of a base station according to Embodiment 3-1 is described with reference to Figure 28a

[0321] ​At step 2800, the base station transmits FCR-related information to the UE. According to the method proposed in the present disclosure, the FCR-related information is transmitted via signaling for indicating an FCR zone, as described above. The FCR zone indication signaling can include a signal indicating the UE to perform a rate matching or puncturing operation in case of a conflict between the FCR and a 5G service zone or a 5G signal.

[0322] At step 2810, the base station transmits data scheduling information of a 5G service to the UE. The data scheduling information includes information on frequency or time resources for data transmission of a 5G service (including a service considered by a 5G system), as described above. The data scheduling information can be transmitted via a higher layer signal or a physical signal.

[0323] At step 2820, the base station transmits / receives data on a 5G service resource other than an FCR zone based on the data scheduling information of the 5G service. For downlink transmission, the base station maps downlink data to be transmitted to a resource on which downlink data transmission is scheduled, other than the FCR zone. For uplink transmission, the base station receives data on a resource on which uplink data transmission is scheduled, other than the FCR zone.

[0324] Next, referring to Figure 28b An operation of a UE according to Embodiment 3-1 is described.

[0325] At step 2850, the UE receives FCR-related information from the base station. According to the method proposed in the present disclosure, the FCR-related information is transmitted via signaling for indicating an FCR zone, as described above. The FCR zone indication signaling can include a signal indicating the UE to perform a rate matching or puncturing operation in case of a conflict between the FCR and a 5G service zone or a 5G signal.

[0326] At step 2860, the UE can receive data scheduling information of a 5G service from the base station. The data scheduling information includes information on frequency or time resources for data transmission of a 5G service (including a service considered by a 5G system), as described above. The data scheduling information can be transmitted via a higher layer signal or a physical signal.

[0327] At step 2870, the UE transmits / receives data on a 5G service resource other than an FCR zone based on the data scheduling information of the 5G service. For downlink transmission, the UE receives data on a resource on which downlink data transmission is scheduled, other than the FCR zone. For uplink transmission, the UE maps and transmits data on a resource on which uplink data is scheduled by the base station, other than the FCR zone.

[0328] Referring to Figure 29A method proposed to solve a situation in which FCR regions and 5G service regions' signals collide with each other according to Embodiment 3-2 of the present application is described.

[0329] Figure 29 FIG. is a diagram illustrating Embodiment 3-2 of the present application.

[0330] In Figure 29 In FIG., a frequency-time resource 2900 used by a 5G system is depicted along a frequency axis 2910 and a time axis 2920. Figure 29 A situation in which eMBB 2930 and 2970 and FCR 2960 are managed by a 5G base station in a framework of a 5G system and a channel state reference signal 2940 and 2950 is transmitted to receive channel state information required for scheduling eMBB data transmission is depicted. Although the drawing depicts an exemplary case in which FCR collides with a channel state reference signal of an eMBB service with each other, the present embodiment is also applicable to a case in which another reference signal (e.g., a data modulation reference signal and a reference signal for a phase difference) collides with FCR, such as mMTC, URLLC, and eMBMS, as well as eMBB.

[0331] FCR region indication signaling can include a signal indicating that a UE performs a rate matching or puncturing operation in a case in which FCR collides with a 5G service region or a 5G signal.

[0332] As described above, a rate matching or puncturing operation can be performed as predetermined according to a 5G transmission signal. In a case in which a UE is signaled a location of an FCR region and whether FCR is actually used, if FCR 2960 collides with a channel state reference signal 2950 for channel state measurement, the UE prioritizes transmission on FCR 2960 and assumes that there is no channel state reference signal overlapping with the region of FCR 2960 on resource 2950 among channel state reference signal transmission resources 2940 and 2950. That is, if it is predetermined to perform puncturing in a case in which a reference signal transmission region for channel state measurement overlaps with an FCR region, the UE performs measurement on a channel state reference signal mapped to a resource not overlapping with a resource element corresponding to an overlapping region to generate and transmit channel state information to a base station. The UE can not perform rate matching or puncturing on a channel state reference signal on a resource 2950 colliding with FCR 2960 among channel state reference signal transmission resources 2940 and 2950 according to a signal indicating a rate matching or puncturing operation.

[0333] Figure 30a and Figure 30b is a flowchart illustrating operations of a base station and a UE according to Embodiment 3-2 of the present application.

[0334] First, referring to Figure 30a The operation of the base station according to Embodiment 3-2 is described.

[0335] At step 3000, the base station transmits FCR-related information to the UE. According to the method proposed in the present application, the FCR-related information is transmitted via signaling for indicating the FCR zone, as described above.

[0336] The FCR zone indication signaling can include a signal indicating that the UE performs a rate matching or puncturing operation in the case where the FCR collides with a 5G service zone or a 5G signal.

[0337] At step 3010, the base station transmits a reference signal to the UE on a reference signal transmission resource other than the FCR zone. As described above, the reference signal includes all reference signals considering supported services in the 5G system.

[0338] Next, referring to Figure 30b The operation of the UE according to Embodiment 3-2 is described.

[0339] At step 3050, the UE receives FCR-related information from the base station. According to the method proposed in the present application, the FCR-related information is transmitted via signaling for indicating the FCR zone, as described above.

[0340] At step 3060, the UE receives a reference signal from the base station on a reference signal transmission resource other than the FCR zone. As described above, the reference signal includes all reference signals considering supported services in the 5G system. The UE performs an operation that should follow the reference signal received at step 3060. For example, if the received reference signal is a channel state reference signal, the UE generates channel state information based on the channel state reference signal and feeds back the generated channel state information to the base station.

[0341] Next, a method proposed for solving the situation in which the FCR zone collides with the signal of the 5G service zone with each other and there is a 5G phase 2 or super 5G UE capable of transmitting / receiving data on the FCR according to Embodiment 3-3 of the present application is described.

[0342] When using signals to notify the UE of the location of the FCR area and whether the FCR is actually in use, if the FCR conflicts with the channel state reference signal used for channel state measurement, a 5G Phase 2 or over 5G UE capable of receiving data on the FCR can operate while understanding the data transmitted on the FCR and the reference signal. In this case, the 5G Phase 2 or over 5G UE can receive reference signals transmitted inside and outside the FCR area, generate channel state information based on the received reference signals, and send the generated channel state information to the base station. In this case, since the channel estimation information sent to the base station is generated based on more channel state reference signals, the base station can perform more accurate data scheduling based on the channel state information.

[0343] Figure 31a and Figure 31b This is a flowchart illustrating the operation of a base station and a UE according to Embodiment 3-3 of the present invention.

[0344] First, refer to Figure 31a The operation of the base station according to Example 3-3 is described.

[0345] At step 3100, the base station sends FCR-related information to the UE. According to the method proposed in this invention, the FCR-related information is sent via signaling for indicating the FCR area, as described above. The FCR area indication signaling may include a signal instructing the UE to perform rate matching or redundancy operations in the event of a conflict between the FCR and a 5G service area or a 5G signal.

[0346] At step 3110, the base station transmits reference signals to the UE both inside and outside the FCR area. As described above, the reference signals include all reference signals for services considered in the 5G system. Reference signal configuration information can be transmitted via higher-layer signals or physical signals.

[0347] Next, refer to Figure 31b The operation of the UE according to Example 3-3 is described.

[0348] The UE receives FCR-related information from the base station. According to the method proposed in this invention, the FCR-related information is transmitted via signaling for indicating the FCR area, as described above.

[0349] At step 3160, the UE receives reference signals from the base station inside and outside the FCR zone. As described above, the reference signals include all reference signals considered to support services in the 5G system. The reference signal configuration information can be transmitted via a higher layer signal or a physical signal. The UE performs an operation that should follow the reference signals received at step 3160. For example, if the received reference signal is a channel state reference signal, the UE generates channel state information based on the channel state reference signal and feeds back the generated channel state information to the base station.

[0350] Figure 32 FIG. 3-4 is a diagram illustrating embodiment 3-4 of the present application.

[0351] Figure 32 An FDD uplink carrier or a TDD carrier is depicted along a frequency axis 3200 and a time axis 3210.

[0352] In a case where an uplink control channel (PUCCH) 3250 or an uplink data channel (PUSCH) 3260 scheduled or configured for the UE in a slot #n 3240 by the base station is transmitted by the UE, the base station can notify the UE in advance of a resource 3220 for which PUCCH transmission is prohibited or a resource 3230 for which PUSCH transmission is prohibited via a higher layer signal or a physical signal. The resource 3220 for which PUCCH transmission is prohibited and the resource 3230 for which PUSCH transmission is prohibited can be configured via the FCR. That is, the time and frequency resources of the resource 3220 for which PUCCH transmission is prohibited and the resource 3230 for which PUSCH transmission is prohibited can be indicated via the FCR.

[0353] Information on the location of a slot configured with the resource 3220 for which PUCCH transmission is prohibited and the resource 3230 for which PUSCH transmission is prohibited (i.e., information on whether the resource 3220 for which PUCCH transmission is prohibited and the resource 3230 for which PUSCH transmission is prohibited are configured only in the slot #n, in multiple slots, or in a specific slot determined by an interval (period) and an offset) can be included in a signal indicating the FCR.

[0354] The UE can transmit a PUCCH or a PUSCH on a PUCCH resource 3250 or a PUSCH resource 3260 other than the resource 3220 for which PUCCH transmission is prohibited or the resource 3230 for which PUSCH transmission is prohibited as notified by the base station. That is, the UE can perform rate matching or puncturing. Whether to perform rate matching or puncturing can be determined per channel as specified in a standard or indicated by a bit field in a signal indicating an operation the UE will take in the FCR.

[0355] Figure 33 FIG. 3-5 is a diagram illustrating embodiment 3-5 of the present application.

[0356] Figure 33 An FDD uplink carrier or a TDD carrier along the frequency axis 3300 and the time axis 3310 is depicted.

[0357] Reference numeral 3320 denotes a downlink control channel configured to UE A having a capability of data communication in a wide frequency band, and reference numeral 3330 denotes a downlink control channel configured to UE B having a capability of data communication in a narrow frequency band. Each UE can transmit capability information to a base station to report whether it has a wideband data communication capability or a narrowband data communication capability, and the base station can configure respective UE frequency bands available for communication via a higher layer signal based on respective UE capability information.

[0358] In the case where the base station intends to configure a narrowband downlink control channel 3330 in a wideband downlink control channel 3320, a resource for transmitting the narrowband downlink control channel 3330 can be notified to UE A in advance via a higher layer signal or a physical signal as an FCR. That is, the time and frequency resources of the downlink control channel 3330 can be notified to UE A via the FCR. Information about the location of a slot in which the FCR is configured (i.e., information about whether the FCR is configured only in a slot #n, in multiple slots, or in a specific slot determined by a gap (period) and an offset) can be included in a signal indicating the FCR. UE A can decode a downlink control channel on resources 3320 other than resources 3330. That is, the UE can perform rate matching or puncturing. Whether to perform rate matching or puncturing can be determined per channel as specified in a standard or indicated by a bit field in a signal indicating an operation the UE will take in the FCR.

[0359] Figure 34 is a block diagram illustrating a base station according to an embodiment of the present application.

[0360] The controller 3400 controls the base station to perform 5G resource allocation (i.e., FCR and 5G service area and 5G signal configuration) in conjunction with the operations of the base station and the UE disclosed with reference to FIGS. 28, 30, 31, and Figure 33 Figure 27 and the management scheme for the case of FCR and 5G service-related data and / or reference signal collision disclosed with reference to Figure 29 and the management scheme for the case of FCR and 5G service-related data and / or reference signal collision disclosed with reference to

[0361] Figure 35 is a block diagram illustrating a UE according to an embodiment of the present application.​

[0362] The controller 3500 is combined with reference to Figures 28, 30, and 31. Figure 33 Publicly available base station and UE operation information and references Figure 27 and Figure 29 The UE is controlled by a publicly disclosed FCR and a management scheme for data and / or reference signal conflicts related to 5G services, so that the UE receives 5G resource allocation information (i.e., FCR and 5G service area and 5G signal configuration information) from the base station via the 5G resource allocation information receiving device 3510 and transmits 5G data scheduled on the allocated 5G resources to the 5G base station via the 5G data sending / receiving device 3520.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control (RRC) message including configuration information about resources for rate matching, the resources for rate matching including a first resource region and a second resource region; receiving, from the base station, downlink control information (DCI) scheduling a physical data shared channel (PDSCH), wherein the DCI includes activation information indicating at least one resource in the first resource region configured based on the configuration information; and receiving, from the base station, data on the PDSCH based on the DCI, wherein the at least one resource in the first resource region indicated based on the activation information is unavailable for the PDSCH, wherein the second resource region configured based on the configuration information is unavailable for the PDSCH, wherein the resources for rate matching are configured by first bit information included in the configuration information, the first bit information indicating at least one resource block in a frequency domain. 2.The method of claim 1, wherein wherein the resources for rate matching are further configured by second bit information included in the configuration information, the second bit information indicating at least one symbol in at least one time slot in a time domain. 3.The method of claim 2, wherein, wherein the resources for rate matching are further configured by third bit information included in the configuration information, the third bit information indicating a repetition pattern of the resources for rate matching. 4.A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a radio resource control (RRC) message including configuration information about resources for rate matching, the resources for rate matching including a first resource region and a second resource region; transmitting, to the terminal, downlink control information (DCI) scheduling a physical data shared channel (PDSCH), wherein the DCI includes activation information indicating at least one resource in the first resource region configured based on the configuration information; and transmitting, to the terminal, data on the PDSCH based on the DCI, wherein the at least one resource in the first resource region indicated based on the activation information is unavailable for the PDSCH, wherein the second resource region configured based on the configuration information is unavailable for the PDSCH, wherein the resources for rate matching are configured by first bit information included in the configuration information, the first bit information indicating at least one resource block in a frequency domain. 5.The method of claim 4, wherein wherein the resources for rate matching are further configured by second bit information included in the configuration information, the second bit information indicating at least one symbol in at least one time slot in a time domain. 6.The method of claim 5, wherein, wherein the resources for rate matching are further configured by third bit information included in the configuration information, the third bit information indicating a repetition pattern of the resources for rate matching. 7.A terminal for a wireless communication system, the terminal comprising: a transceiver (3510, 3520); and a controller (3500) coupled with the transceiver and configured to: receive, from a base station, a radio resource control (RRC) message including configuration information about resources for rate matching, the resources for rate matching including a first resource region and a second resource region; receive, from the base station, downlink control information (DCI) scheduling a physical data shared channel (PDSCH), wherein the DCI includes activation information indicating at least one resource in the first resource region configured based on the configuration information; and receive, from the base station, data on the PDSCH based on the DCI, wherein the at least one resource in the first resource region indicated based on the activation information is unavailable for the PDSCH, wherein the second resource region configured based on the configuration information is unavailable for the PDSCH, wherein the resources for rate matching are configured by first bit information included in the configuration information, the first bit information indicating at least one resource block in a frequency domain.

8. The terminal of claim 7, wherein wherein the resources for rate matching are further configured by second bit information included in the configuration information, the second bit information indicating at least one symbol in at least one time slot in a time domain.

9. The terminal of claim 8, wherein wherein the resources for rate matching are further configured by third bit information included in the configuration information, the third bit information indicating a repetition pattern of the resources for rate matching.

10. A base station for a wireless communication system, the base station comprising: a transceiver (3420, 3430); and a controller (3400) coupled with the transceiver and configured to: transmit, to a terminal, a radio resource control (RRC) message including configuration information about resources for rate matching, the resources for rate matching including a first resource region and a second resource region, transmit, to the terminal, downlink control information (DCI) scheduling a physical data shared channel (PDSCH), wherein the DCI includes activation information indicating at least one resource in the first resource region configured based on the configuration information; and transmit, to the terminal, data on the PDSCH based on the DCI, wherein the at least one resource in the first resource region indicated based on the activation information is unavailable for the PDSCH, wherein the second resource region configured based on the configuration information is unavailable for the PDSCH, wherein the resources for rate matching are configured by first bit information included in the configuration information, the first bit information indicating at least one resource block in a frequency domain.

11. The base station of claim 10, wherein wherein the resources for rate matching are further configured by second bit information included in the configuration information, the second bit information indicating at least one symbol in at least one time slot in a time domain.

12. The base station of claim 11, wherein The resources for rate matching are also configured by third bit information included in the configuration information, and the third bit information indicates a repetition pattern of the resources for rate matching.

Images