Method and apparatus for user equipment power saving in wireless communication system

Abstract

The present disclosure relates to a communication technique and a system for integrating a 5G communication system with IoT technology to support higher data transmission rates than those of 4G systems. The present disclosure may be applied to intelligent services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. Additionally, the present disclosure provides a method and apparatus for reducing terminal power consumption in a wireless communication system.

Description

Technology Field

[0001] The present disclosure relates to a method and apparatus for reducing power consumption of a terminal in a wireless communication system. Background Technology

[0002] Efforts are being made to develop improved 5G (5th generation) communication systems or pre-5G communication systems to meet the increasing demand for wireless data traffic following the commercialization of 4G (4th generation) communication systems. For this reason, 5G communication systems or pre-5G communication systems are referred to as systems beyond 4G networks or systems following LTE (Long-Term Evolution) systems. To achieve high data transmission rates, the implementation of 5G communication systems in the mmWave band (e.g., the 60 GHz band) is being considered. In order to mitigate path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, beamforming, massive array multiple input / output (massive MIMO), full-dimensional multiple input / output (Full Dimensional MIMO: FD-MIMO), array antenna, analog beam-forming, and large-scale antenna technologies are being discussed in 5G communication systems.In addition, to improve the network of the system, technologies such as advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation are being developed in 5G communication systems. Furthermore, in 5G systems, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access) are being developed.

[0003] Meanwhile, the Internet is evolving from a human-centric network where humans generate and consume information into an IoT (Internet of Things) network that processes information by exchanging it among distributed components, such as objects. IoE (Internet of Everything) technology, which combines IoT with Big Data processing technologies through connections with cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required; consequently, technologies such as sensor networks, Machine-to-Machine (M2M) communication, and Machine-Type Communication (MTC) are currently being researched to facilitate the connection of objects. In an IoT environment, intelligent IT services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT technologies with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0004] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, Machine to Machine (M2M), and Machine Type Communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology, as previously explained, can also be considered an example of the convergence of 3eG and IoT technologies.

[0005] As the aforementioned developments in wireless communication systems have enabled the provision of various services, measures to ensure the smooth delivery of these services are required. In particular, communication methods that conserve terminal power are needed to provide services to users for longer periods. The problem to be solved

[0006] The disclosed embodiment aims to provide a communication method and device for saving power of a terminal in a wireless communication system. means of solving the problem

[0007] A method for a terminal to control power in a wireless communication system according to one embodiment of the present disclosure may include: receiving power saving signal (POSS) setting information from a base station; monitoring a Physical Downlink Control Channel (PDCCH) for the POSS based on the POSS setting information; receiving downlink control information (DCI) corresponding to the POSS through the PDCCH; and performing a power saving operation indicated by the DCI. Effects of the invention

[0008] The disclosed embodiment can provide a communication method and device that can effectively save power of a terminal in a mobile communication system. Brief explanation of the drawing

[0009] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain of a 5G system. Figure 2 is a diagram illustrating the frame, subframe, and slot structure of a 5G system. Figure 3 is a diagram illustrating an example of a bandwidth portion setting of a 5G system. Figure 4 is a diagram illustrating an example of a control area setting for a downlink control channel of a 5G system. Figure 5 is a diagram illustrating the structure of a downlink control channel of a 5G system. Figure 6 is a diagram illustrating an example of DRX operation of a 5G system. FIG. 7 is a drawing illustrating an example of a POSS setting method according to an embodiment of the present disclosure. FIG. 8 is a drawing illustrating an example of a POSS setting method according to an embodiment of the present disclosure. FIG. 9 is a drawing illustrating a base station and terminal procedure according to one embodiment of the present disclosure. FIG. 10 is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure. FIG. 11 is a block diagram illustrating the internal structure of a base station according to one embodiment of the present disclosure. Specific details for implementing the invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0011] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0012] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the dimensions of each component do not entirely reflect their actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0013] The advantages and features of the present disclosure, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration might unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout the specification.

[0014] Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), radio access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In this disclosure, a downlink (DL) refers to a wireless transmission path of a signal transmitted by a base station to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal transmitted by a terminal to a base station. Furthermore, while LTE, LTE-A, or 5G systems may be described as examples below, embodiments of this disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included therein, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications made at the discretion of a person with skilled technical knowledge, without significantly departing from the scope of the present disclosure.

[0015] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing instruction means to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0016] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0017] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiments, 'parts' may include one or more processors.

[0018] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 3GPP’s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2’s HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE’s 802.16e.

[0019] As a representative example of the above-mentioned broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The above-mentioned multiple access method can distinguish the data or control information of each user by allocating and operating time-frequency resources to be sent for each user so that they do not overlap, that is, so that orthogonality is established.

[0020] As a future communication system following LTE, that is, a 5G communication system, it must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy various requirements simultaneously must be supported. Services being considered for the 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0021] eMBB aims to provide data transmission speeds that are superior to those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20 Gbps in the downlink and 10 Gbps in the uplink from the perspective of a single base station. Furthermore, while providing these peak data rates, the 5G communication system must also provide an increased user-perceived data rate. To satisfy these requirements, it necessitates improvements in various transmission and reception technologies, including enhanced Multi-Input Multi-Output (MIMO) transmission technology. Additionally, while LTE transmits signals using a maximum bandwidth of 20 MHz in the 2 GHz band, the 5G communication system can meet the data transmission speeds required by using a frequency bandwidth wider than 20 MHz in frequency bands of 3–6 GHz or above 6 GHz.

[0022] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC requires support for a large number of terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT devices are attached to various sensors and equipment to provide communication functions, the system must be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²). Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones not covered by cells, such as building basements; therefore, they may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace terminal batteries, a very long battery life of 10 to 15 years may be required.

[0023] Finally, URLLC is a mission-critical cellular-based wireless communication service. For example, consider services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer very low latency and very high reliability. For instance, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and simultaneously 10 -5The following packet error rate requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a Transmit Time Interval (TTI) smaller than other services, and at the same time, design considerations may be required to allocate a wide resource in the frequency band to ensure the reliability of the communication link.

[0024] The three 5G services, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted within a single system. In this case, different transmission and reception techniques and parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[0025] The frame structure of the 5G system will be explained in more detail below with reference to the drawings.

[0026] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource domain where data or control channels are transmitted in a 5G system.

[0027] The horizontal axis of FIG. 1 represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a resource element (RE, 101), which can be defined as one OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and one subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form a single resource block (Resource Block, RB, 104).

[0028] Figure 2 is a diagram illustrating a slot structure considered in a 5G system.

[0029] FIG. 2 illustrates an example of a frame (200), subframe (201), and slot (202) structure. One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and thus one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). One subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per one subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In one example of FIG. 2, cases where μ=0 (204) and μ=1 (205) are set as the subcarrier spacing value are illustrated. When μ=0 (204), one subframe (201) may be composed of one slot (202), and when μ=1 (205), one subframe (201) may be composed of two slots (203). That is, the number of slots per one subframe ( ) may vary, and accordingly, the number of slots per frame ( ) may vary. Depending on each subcarrier spacing setting μ and It can be defined by Table 1 below.

[0030] [Table 1]

[0031]

[0032] Next, the Bandwidth Part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0033] Figure 3 is a diagram illustrating an example of a configuration for a bandwidth portion in a 5G communication system.

[0034] FIG. 3 shows an example in which the terminal bandwidth (UE bandwidth) (300) is configured into two bandwidth portions, namely bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station may configure one or more bandwidth portions for the terminal and may configure the following information for each bandwidth portion.

[0035] [Table 2]

[0036]

[0037] Of course, the above examples are not limited, and various parameters related to bandwidth portions may be configured for the terminal in addition to the above configuration information. The above information may be transmitted by the base station to the terminal via upper-layer signaling, for example, Radio Resource Control (RRC) signaling. At least one of the configured bandwidth portions may be activated. Whether a configured bandwidth portion is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling or dynamically via Downlink Control Information (DCI).

[0038] According to some embodiments, prior to the Radio Resource Control (RRC) connection, the terminal may receive an Initial Bandwidth Part (Initial BWP) for initial connection from the base station via a Master Information Block (MIB). More specifically, during the initial connection phase, the terminal may receive configuration information for a Control Resource Set (CORESET) and a Search Space via the MIB, through which a PDCCH can be transmitted to receive system information required for initial connection (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1). The Control Resource Set and Search Space configured via the MIB may each be considered as Identity (ID) 0. The base station may notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and numerology, for Control Resource Set #0. Additionally, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and occasion for Control Resource Set #0, i.e., configuration information for Search Space #0. The terminal may consider the frequency region set as control region #0 obtained from the MIB as the initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0039] The settings for the bandwidth portion supported by the above 5G can be used for various purposes.

[0040] According to some embodiments, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth portion setting. For example, by setting the frequency position of the bandwidth portion (setting information 2) to the terminal, the terminal can transmit and receive data at a specific frequency position within the system bandwidth.

[0041] In addition, according to some embodiments, a base station may set multiple bandwidth portions for a terminal for the purpose of supporting different numerologies. For example, to support data transmission and reception using both a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a terminal, two bandwidth portions may be set to subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when data transmission and reception is to be performed with a specific subcarrier interval, the bandwidth portion set to that subcarrier interval may be activated.

[0042] In addition, according to some embodiments, a base station may set a bandwidth portion having different bandwidth sizes for the purpose of reducing the power consumption of the terminal. For example, if the terminal supports a very large bandwidth, such as 100 MHz, and always transmits and receives data using that bandwidth, very large power consumption may occur. In particular, in a situation where there is no traffic, performing monitoring of an unnecessary downlink control channel using a large bandwidth of 100 MHz can be very inefficient in terms of power consumption. To reduce the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth, such as 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0043] In the method for configuring the above bandwidth portion, terminals prior to RRC connection (Connected) can receive configuration information for the Initial Bandwidth Part through the Master Information Block (MIB) during the initial connection phase. More specifically, the terminal can receive a Control Resource Set (CORESET) for a downlink control channel through which Downlink Control Information (DCI) scheduling System Information Blocks (SIB) can be transmitted from the MIB of the Physical Broadcast Channel (PBCH). The bandwidth of the control resource set by the MIB can be considered as the Initial Bandwidth Part, and through the configured Initial Bandwidth Part, the terminal can receive the Physical Downlink Shared Channel (PDSCH) through which SIBs are transmitted. In addition to receiving SIBs, the Initial Bandwidth Part may also be utilized for Other System Information (OSI), paging, and Random Access.

[0044] When one or more bandwidth parts are set for a terminal, the base station may instruct the terminal to change the bandwidth part using the Bandwidth Part Indicator field within the DCI. For example, in FIG. 3, if the currently active bandwidth part of the terminal is Bandwidth Part #1 (301), the base station may instruct the terminal to Bandwidth Part #2 (302) using the Bandwidth Part Indicator within the DCI, and the terminal may perform a bandwidth part change to Bandwidth Part #2 (302) indicated by the received Bandwidth Part Indicator within the DCI.

[0045] As mentioned above, since DCI-based bandwidth part changes can be directed by a DCI scheduling a PDSCH or PUSCH, when a terminal receives a request to change a bandwidth part, it must be able to receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard specifies requirements for the delay time (TBWP) required when changing a bandwidth part, and can be defined, for example, as follows.

[0046] [Table 2-1]

[0047]

[0048] The requirements for bandwidth part change delay time support Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth part delay time type to the base station.

[0049] In accordance with the aforementioned requirements for the bandwidth part change delay time, if the terminal receives a DCI containing a bandwidth part change indicator in slot n, the terminal performs a change to the new bandwidth part indicated by the bandwidth part change indicator in slot n+T BWP Completion can be achieved at a time no later than that, and transmission and reception for the data channel scheduled by the corresponding DCI can be performed in the changed new bandwidth portion. If the base station intends to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP By considering ), time-domain resource allocation for a data channel can be determined. That is, when a base station schedules a data channel with a new bandwidth part, in the method for determining time-domain resource allocation for a data channel, the corresponding data channel can be scheduled after the bandwidth part change delay time. Accordingly, the terminal [is notified] that the DCI instructing the bandwidth part change is the bandwidth part change delay time (T BWPYou may not expect to indicate a slot offset (K0 or K2) value smaller than )

[0050] If a terminal receives a DCI (e.g., DCI format 1_1 or 0_1) indicating a change in bandwidth part, the terminal may not perform any transmission or reception during a time interval corresponding to the time interval from the third symbol of the slot in which the PDCCH containing the said DCI was received to the beginning of the slot indicated by the slot offset value (K0 or K2) indicated by the time domain resource allocation indicator field within the said DCI. For example, if a terminal receives a DCI indicating a change in bandwidth part in slot n, and the slot offset value indicated by the said DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0051] Next, we will explain the SS (Synchronization Signal) / PBCH block in 5G.

[0052] An SS / PBCH block may refer to a physical layer channel block composed of PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it is as follows.

[0053] - PSS: A signal that serves as the reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0054] - SSS: Serves as the reference for downlink time / frequency synchronization and provides the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0055] - PBCH: Provides essential system information required for transmitting and receiving data channels and control channels of the terminal. The essential system information may include search space-related control information representing wireless resource mapping information of the control channel, scheduling control information for a separate data channel that transmits system information, etc.

[0056] - SS / PBCH block: An SS / PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks may be transmitted within a time of 5ms, and each transmitted SS / PBCH block may be distinguished by an index.

[0057] The terminal can detect PSS and SSS during the initial connection phase and can decode PBCH. It can obtain MIB from PBCH and receive a Control Resource Set (CORESET) #0 from it (which may correspond to a control resource set with a control resource index of 0). The terminal can perform monitoring of Control Resource Set #0 by assuming that the selected SS / PBCH block and the Demodulation Reference Signal (DMRS) transmitted from Control Resource Set #0 are Quasi-Co-Locations (QCL). The terminal can receive system information using downlink control information transmitted from Control Resource Set #0. The terminal can obtain configuration information related to the Random Access Channel (RACH) required for initial connection from the received system information. The terminal can transmit a Physical RACH (PRACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information regarding the SS / PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among the respective SS / PBCH blocks and is monitoring the associated control area #0.

[0058] Next, Downlink Control Information (DCI) in 5G systems will be explained in detail.

[0059] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) is transmitted from the base station to the terminal via DCI. The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields selected between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0060] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after undergoing channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled into a Radio Network Temporary Identifier (RNTI) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI is not transmitted explicitly but is included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using the assigned RNTI; if the CRC check result is correct, the terminal knows that the message has been transmitted to it.

[0061] For example, a DCI scheduling a PDSCH for System Information (SI) can be scrambled to SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message can be scrambled to RA-RNTI. A DCI scheduling a PDSCH for a Paging message can be scrambled to P-RNTI. A DCI notifying a Slot Format Indicator (SFI) can be scrambled to SFI-RNTI. A DCI notifying Transmit Power Control (TPC) can be scrambled to TPC-RNTI. A DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled to C-RNTI (Cell RNTI).

[0062] DCI format 0_0 can be used as a countermeasure DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI may include, for example, the following information.

[0063] [Table 3]

[0064]

[0065] DCI format 0_1 ​​can be used as a non-defense DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI may include, for example, the following information.

[0066] [Table 4]

[0067]

[0068] DCI format 1_0 can be used as a countermeasure DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI may include, for example, the following information.

[0069] [Table 5]

[0070]

[0071] DCI format 1_1 can be used as a non-defense DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI may include, for example, the following information.

[0072] [Table 6]

[0073]

[0074] The following describes the time domain resource allocation method for data channels in a 5G communication system.

[0075] The base station may set a table for time-domain resource allocation information for the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH) for the terminal using upper-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of a maximum of maxNrofDL-Allocations = 16 entries may be set, and for PUSCH, a table consisting of a maximum of maxNrofUL-Allocations = 16 entries may be set. Time domain resource allocation information may include, for example, PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information regarding the position and length of the starting symbol for which the PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information such as that shown in the table below may be notified from the base station to the terminal.

[0076] [Table 7]

[0077]

[0078] [Table 8]

[0079]

[0080] The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information via L1 signaling (e.g., DCI) (e.g., by indicating the 'time domain resource allocation' field within the DCI). The terminal may obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0081] In the following, the downlink control channel in a 5G communication system will be explained in more detail with reference to the drawings.

[0082] FIG. 4 illustrates an example of a control resource set (CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system. FIG. 4 illustrates an example in which two control resources (control resource #1 (401), control resource #2 (402)) are set within a terminal bandwidth part (UE bandwidth part) (410) on the frequency axis and one slot (420) on the time axis. The control resources (401, 402) can be set in a specific frequency resource (403) within the entire terminal bandwidth part (410) on the frequency axis. On the time axis, they can be set with one or more OFDM symbols and can be defined as the control resource set duration (Control Resource Set Duration, 404). Referring to the example illustrated in FIG. 4, control resource #1 (401) is set with a control resource length of 2 symbols, and control resource #2 (402) is set with a control resource length of 1 symbol.

[0083] The control domain in the aforementioned 5G can be configured by a base station to a terminal via upper-layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Configuring a control domain to a terminal means providing information such as a control domain identifier, the frequency location of the control domain, and the symbol length of the control domain. For example, the following information may be included.

[0084] [Table 9]

[0085]

[0086] In Table 9, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control area.

[0087] FIG. 5 is a diagram showing an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in 5G. According to FIG. 5, the basic unit of time and frequency resources that constitute a control channel can be called a REG (Resource Element Group, 503), and the REG (503) can be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, that is, 12 subcarriers. A base station can construct a downlink control channel allocation unit by concatenating REGs (503).

[0088] As illustrated in FIG. 5, if the basic unit to which a downlink control channel is allocated in 5G is called a CCE (Control Channel Element, 504), then 1 CCE (504) can be composed of multiple REGs (503). For example, the REG (503) illustrated in FIG. 5 can be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), then 1 CCE (504) can be composed of 72 REs. When a downlink control area is established, the area can be composed of multiple CCEs (504), and a specific downlink control channel can be mapped to one or multiple CCEs (504) and transmitted according to the Aggregation Level (AL) within the control area. The CCEs (504) in the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0089] The basic unit of the downlink control channel, namely the REG (503) shown in FIG. 5, may include both the REs to which the DCI is mapped and the DMRS (505), which is a reference signal for decoding, to which the area is mapped. As shown in FIG. 5, three DMRS (505) may be transmitted within one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the Aggregation Level (AL), and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The terminal must detect the signal without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates consisting of CCEs that a terminal must attempt to decode at a given aggregation level, and since there are various aggregation levels that form a group of 1, 2, 4, 8, or 16 CCEs, a terminal may have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

[0090] Search spaces can be classified into common search spaces and UE-specific search spaces. A certain group of terminals or all terminals may examine the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages regarding system information. For example, PDSCH scheduling allocation information for the transmission of SIBs containing cell operator information can be received by examining the common search space of the PDCCH. In the case of the common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a pre-arranged set of CCEs. Scheduling allocation information for a UE-specific PDSCH or PUSCH can be received by examining the UE-specific search space of the PDCCH. The UE-specific search space can be defined specifically as a function of the terminal's identity and various system parameters.

[0091] In 5G, parameters for the search space for a PDCCH can be configured from the base station to the terminal via upper-layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station may configure the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and the control domain index to be monitored in the search space. For example, parameters for the search space for a PDCCH may include the following information.

[0092] [Table 10]

[0093]

[0094] According to the configuration information, the base station may set one or multiple sets of search spaces for the terminal. According to some embodiments, the base station may set search space set 1 and search space set 2 for the terminal, and may set DCI format A scrambled with X-RNTI in search space set 1 to be monitored in a common search space, and may set DCI format B scrambled with Y-RNTI in search space set 2 to be monitored in a terminal-specific search space.

[0095] According to the configuration information, one or more sets of search spaces may exist in a common search space or a terminal-specific search space. For example, Search Space Set #1 and Search Space Set #2 may be configured as a common search space, and Search Space Set #3 and Search Space Set #4 may be configured as a terminal-specific search space.

[0096] In the common search space, the following combinations of DCI formats and RNTI can be monitored. Of course, they are not limited to the examples below.

[0097] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0098] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0099] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0100] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0101] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0102] In terminal-specific search spaces, the following combinations of DCI formats and RNTI can be monitored. Of course, they are not limited to the examples below.

[0103] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0104] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0105] The specified RNTIs may follow the definitions and uses below.

[0106] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH scheduling

[0107] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

[0108] CS-RNTI (Configured Scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.

[0109] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase

[0110] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is transmitted.

[0111] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0112] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is pucturing.

[0113] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to instruct power control commands to the PUSCH

[0114] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to instruct power control commands to the PUCCH

[0115] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS

[0116] The aforementioned specified DCI formats may follow the definitions below.

[0117] [Table 11]

[0118]

[0119] In 5G, the search space of aggregation level L in the control domain p and search space set s can be expressed as the following mathematical formula.

[0120] [Mathematical Formula 1]

[0121]

[0122] [Mathematical Formula 2]

[0123]

[0124] In 5G, as multiple sets of search spaces can be configured with different parameters (e.g., the parameters in Table 10), the set of search space sets monitored by the terminal at each point in time may vary. For example, if search space set #1 is configured with an X-slot period and search space set #2 is configured with a Y-slot period and X and Y are different, the terminal may monitor both search space set #1 and search space set #2 in a specific slot, and monitor either search space set #1 or search space set #2 in a specific slot.

[0125] When multiple sets of search spaces are configured for a terminal, the following conditions may be considered in determining the set of search spaces that the terminal must monitor.

[0126] [Condition 1: Limit on the maximum number of PDCCH candidates]

[0127] The number of PDCCH candidates that can be monitored per slot is M μ Does not exceed. M μ The subcarrier interval is 15·2 μ It can be defined as the maximum number of PDCCH candidates per slot in a cell set to kHz, and can be defined by the table below.

[0128] [Table 12]

[0129]

[0130] [Condition 2: Limit on Maximum CCEs]

[0131] The number of CCEs constituting the entire search space per slot (where the entire search space refers to the entire set of CCEs corresponding to the union area of ​​multiple search space sets) is C μ Does not exceed C μ The subcarrier interval is 15·2 μ It can be defined as the maximum number of CCEs per slot in a cell set to kHz, and can be defined by the table below.

[0132] [Table 13]

[0133]

[0134] For the convenience of explanation, a situation in which both of the above conditions 1 and 2 are satisfied at a specific point in time is defined as "condition A". Therefore, not satisfying condition A may mean not satisfying at least one of the above conditions 1 and 2.

[0135] Depending on the configuration of the base station's search space sets, there may be cases where Condition A is not satisfied at a specific point in time. If Condition A is not satisfied at a specific point in time, the terminal may select and monitor only some of the search space sets configured to satisfy Condition A at that point in time, and the base station may transmit a PDCCH to the selected search space sets.

[0136] You can follow the method below to select some of the search spaces from the entire set of configured search spaces.

[0137] [Method 1]

[0138] If condition A for PDCCH is not satisfied at a specific time point (slot),

[0139] The terminal (or base station) may preferentially select a search space set whose search space type is set as a common search space among the search space sets existing at that time, over a search space set whose search space type is set as a terminal-specific search space.

[0140] When all sets of search spaces configured as common search spaces have been selected (i.e., when Condition A is satisfied even after selecting all search spaces configured as common search spaces), the terminal (or base station) may select sets of search spaces configured as terminal-specific search spaces. In this case, if there are multiple sets of search spaces configured as terminal-specific search spaces, the search space set with a lower search space set index may have a higher priority. Considering the priority, sets of terminal-specific search spaces may be selected within the range where Condition A is satisfied.

[0141] Figure 6 is a diagram illustrating DRX (Discontinuous Reception).

[0142] DRX (Discontinuous Reception) is an operation in which a terminal using a service receives data discontinuously while in an RRC connected state, where a wireless link is established between the base station and the terminal. When DRX is applied, the terminal can turn on the receiver at specific points to monitor the control channel, and turn off the receiver if no data is received for a certain period to reduce the terminal's power consumption. DRX operation can be controlled by a MAC layer device based on various parameters and timers.

[0143] Referring to FIG. 6, Active time (605) is the time during which the terminal wakes up at each DRX cycle to monitor the PDCCH. Active time (605) can be defined as follows.

[0144] - drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer is running; or

[0145] - a Scheduling Request is sent on PUCCH and is pending; or

[0146] - a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity has not been received after successful reception of a Random Access Response for the Random Access Preamble not selected by the MAC entity among the contention-based Random Access Preamble

[0147] drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-ContentionResolutionTimer, etc. are timers whose values ​​are set by the base station, and have the function of setting the terminal to monitor PDCCH when certain conditions are satisfied.

[0148] drx-onDurationTimer (615) is a parameter for setting the minimum time the terminal stays awake in the DRX cycle. drx-InactivityTimer (620) is a parameter for setting the additional time the terminal stays awake when receiving a PDCCH (630) instructing a new uplink transmission or downlink transmission. drx-RetransmissionTimerDL is a parameter for setting the maximum time the terminal stays awake to receive a downlink retransmission in the downlink HARQ procedure. drx-RetransmissionTimerUL is a parameter for setting the maximum time the terminal stays awake to receive an uplink retransmission grant in the uplink HARQ procedure. drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL can be set as, for example, time, number of subframes, number of slots, etc. ra-ContentionResolutionTimer is a parameter for monitoring PDCCH in a random access procedure.

[0149] The inActive time (610) is a time during which the PDCCH is not monitored or / or the PDCCH is not received during the DRX operation, and the remaining time after subtracting the Active time (605) from the total time of performing the DRX operation may be the inActive time (610). If the terminal does not monitor the PDCCH during the Active time (605), it may enter a sleep or inActive state to reduce power consumption.

[0150] The DRX cycle refers to the period during which a terminal wakes up and monitors the PDCCH. In other words, it refers to the time interval or on-duration occurrence cycle between when the terminal monitors a PDCCH and when it monitors the next PDCCH. There are two types of DRX cycles: short DRX cycle and long DRX cycle. The short DRX cycle can be applied optionally.

[0151] Long DRX cycle (625) is the longer of the two DRX cycles set in the terminal. While operating as Long DRX, the terminal restarts drx-onDurationTimer (615) at a point where Long DRX cycle (625) has elapsed from the starting point (e.g., start symbol) of drx-onDurationTimer (615). When operating as Long DRX cycle (625), the terminal can start drx-onDurationTimer (615) in a slot after drx-SlotOffset in a subframe satisfying [Equation 2] below. Here, drx-SlotOffset refers to the delay before starting drx-onDurationTimer (615). drx-SlotOffset can be set, for example, as time, the number of slots, etc.

[0152] [Mathematical Formula 2]

[0153] [(SFN Υ 10) + subframe number] modulo (drx-LongCycle) = drx-StartOffset

[0154] At this time, drx-LongCycleStartOffset may include Long DRX cycle (625) and drx-StartOffset, and may be used to define the subframe to start Long DRX cycle (625). drx-LongCycleStartOffset may be set, for example, as time, number of subframes, number of slots, etc.

[0155] A short DRX cycle is the shorter of the two DRX cycles defined in the terminal. The terminal operates in a long DRX cycle (625), and when a specific event occurs during the active time (605), such as receiving a PDCCH (630) instructing a new uplink transmission or downlink transmission, it starts or restarts the drx-InactivityTimer (620), and if the drx-InactivityTimer (620) expires or a DRX command MAC CE is received, it can operate in a short DRX cycle. For example, in FIG. 6, the terminal starts the drx-ShortCycleTimer at the time of the previous drx-onDurationTimer (615) or drx-InactivityTimer (620) expiration, and can operate in a short DRX cycle until the drx-ShortCycleTimer expires. When the terminal receives a PDCCH (630) instructing a new uplink transmission or downlink transmission, it may extend the Active Time (605) or delay the arrival of the InActive Time (610) in anticipation of additional uplink transmission or downlink transmission in the future. While the terminal is operating in short DRX, it starts the drx-onDurationTimer (615) again at a time when a short DRX cycle has elapsed from the start of the previous on duration. After that, when the drx-ShortCycleTimer expires, the terminal operates in the Long DRX cycle (625) again.

[0156] When operating in a short DRX cycle, the terminal may start drx-onDurationTimer (615) after drx-SlotOffset in a subframe satisfying [Equation 3] below. Here, drx-SlotOffset represents a delay before starting drx-onDurationTimer (615). drx-SlotOffset can be set, for example, to time, number of slots, etc.

[0157] [Mathematical Formula 3]

[0158] [(SFN Х 10) + subframe number] modulo (drx-ShortCycle) = (drx-StartOffset) modulo (drx-ShortCycle)

[0159] Here, drx-ShortCycle and drx-StartOffset can be used to define the subframe to start the Short DRX cycle. drx-ShortCycle and drx-StartOffset can be set, for example, as time, number of subframes, number of slots, etc.

[0160] Up to this point, the DRX operation has been described with reference to FIG. 6. According to one embodiment, the terminal can reduce the power consumption of the terminal by performing the DRX operation. However, even if the terminal performs the DRX operation, the terminal does not always receive the PDCCH associated with the terminal during Active Time (605). Therefore, in one embodiment of the present disclosure, a signal controlling the operation of the terminal can be provided to save the power of the terminal more efficiently.

[0161] In the following, we will specifically explain the carrier aggregation and scheduling methods in 5G communication systems.

[0162] A terminal can receive multiple cells (Cell or CC (Component Carrier)) from a base station and can receive a setting regarding whether cross-carrier scheduling is enabled for the cells configured in the terminal. If cross-carrier scheduling is enabled for a specific cell (Cell A, Scheduled Cell), PDCCH monitoring for Cell A is not performed at Cell A but can be performed at another cell (Cell B, Scheduling Cell) designated for cross-carrier scheduling. In this case, the Scheduled Cell (Cell A) and the Scheduling Cell (Cell B) can be configured with different numerologies. Here, the numerology may include subcarrier spacing, cyclic prefix, etc. When the numerologies of cell A and cell B are different, when cell B's PDCCH schedules cell A's PDSCH, a minimum scheduling offset as follows may be additionally considered between PDCCH and PDSCH.

[0163] [Cross-Carrier Scheduling Method]

[0164] - Subcarrier spacing of Cell B (μ B ) is the subcarrier spacing (μ) of cell A A If it is smaller than ), the PDSCH can be scheduled starting from the next PDSCH slot corresponding to X symbols after the last symbol of the PDCCH received at Cell B. Here, X is μ B It may vary depending on, and μ B When =15kHz, X=4 symbols, μ B When =30kHz, X=4 symbols, μ B When =60kHz, X can be defined as 8 symbols.

[0165] - Subcarrier spacing of Cell B (μ B ) is the subcarrier spacing (μ) of cell A AIf it is greater than ), the PDSCH can be scheduled starting from the point X symbols after the last symbol of the PDCCH received by Cell B. Here, X is μ B It may vary depending on, and μ B When =30kHz, X=4 symbols, μ B When =60kHz, X=8 symbols, μ B When =120kHz, X can be defined as 12 symbols.

[0166] In the following, the term "upper layer signaling" may refer to a signaling corresponding to at least one or a combination of at least one of the following signalings.

[0167] - MIB (Master Information Block)

[0168] - SIB (System Information Block) or SIB

[0169] - RRC (Radio Resource Control)

[0170] - MAC (Medium Access Control) CE (Control Element)

[0171] - UE Capability Reporting

[0172] Additionally, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of the following physical layer channels or signaling methods.

[0173] - PDCCH (Physical Downlink Control Channel)

[0174] - DCI (Downlink Control Information)

[0175] - Terminal-specific (UE-specific) DCI

[0176] - Group common DCI

[0177] - Common DCI

[0178] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0179] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0180] - PUCCH (Physical Uplink Control Channel)

[0181] - UCI (Uplink Control Information)

[0182] <First Embodiment>

[0183] In next-generation mobile communication systems, a base station may transmit an L1 signal to a terminal for the purpose of reducing power consumption of the terminal, and this may be referred to as a Power Saving Signal (POSS). Of course, it is not limited to the examples described above, and the Power Saving Signal may be expressed by various names such as a Power Control Signal or a Power Setting Signal. More specifically, in one embodiment of the present disclosure, the Power Saving Signal (POSS) may be referred to as a Wake Up Signal (WUS), Power Control Signal, DRX Activation Signal, On Duration Activation Signal, or On Duration Timer Activation Signal.

[0184] According to one embodiment of the present disclosure, a terminal can monitor the PDCCH to detect Downlink Control Information (DCI) corresponding to the POSS. The DCI format corresponding to the POSS may be referred to as DCI format 3_0. In this case, the CRC of DCI format 3_0 may be scrambled with a specific RNTI (Radio Network Temporary Identifier). The specific RNTI may be, for example, called PS-RNTI. Additionally, PS-RNTI may be a newly defined RNTI or an existing RNTI. Alternatively, the terminal may receive the PS-RNTI from the base station through upper-layer signaling. The terminal may receive the DCI format 3_0 corresponding to the POSS by assuming that it has been scrambled with the PS-RNTI. In this case, when the terminal performs blind decoding for the DCI format 3_0, it may de-scramble using the PS-RNTI.

[0185] According to one embodiment of the present disclosure, a terminal can set a search space for monitoring DCI format 3_0 corresponding to POSS from a base station through upper layer signaling. The base station can set the search space for DCI format 3_0 corresponding to POSS for the terminal based on the parameters of [Table 10] described above. To summarize, the following information can be set.

[0186] [Exploration Space Settings Information]

[0187] - Search space ID (Search space identifier)

[0188] - CORESET ID (Control Area Identifier)

[0189] - monitoringSlotPeriodicityAndOffset (slot level monitoring period and offset)

[0190] - duration (monitoring length): Number of consecutive slots that a SearchSpace lasts in every occasion, ie, upon every period as given in the periodicityAndOffset. If the field is absent, the UE applies the value 1 slot, except for DCI format 2_0. The UE ignores this field for DCI format 2_0. The maximum valid duration is periodicity-1 (periodicity as given in the monitoringSlotPeriodicityAndOffset).

[0191] - monitoringSymbolsWithinSlot (monitoring occasion symbols within the slot)

[0192] - nrofCandidates (number of PDCCH candidates per aggregation level)

[0193] - searchSpaceType (searchspace type)

[0194] -- common (common search space)

[0195] -- ue-Specific (terminal-specific search space)

[0196] According to one embodiment of the present disclosure, a terminal can determine a PDCCH monitoring occasion for a POSS based on search space setting information for a DCI format 3_0 corresponding to a POSS received from a base station. The terminal can perform blind decoding at each PDCCH monitoring occasion for a POSS. If the terminal detects a DCI format 3_0, the terminal can perform subsequent operations according to instruction information within the detected DCI format 3_0. The DCI format 3_0 may include, for example, the following control information.

[0197] - 1st control information: An indicator that controls the PDCCH monitoring behavior at a DRX occasion that follows a POSS monitoring occasion (or may be expressed as an indicator indicating wake-up status, or ps-Index, etc.).

[0198] -- For example, if the value of this field indicates "0", the terminal may not perform monitoring of the PDCCH during subsequent DRX Active Time. (Alternatively, the terminal may not start the drx-onDurationTimer during subsequent DRX occasions. The aforementioned behavior corresponding to a field value of "0" may correspond to the terminal not waking up behavior.)

[0199] -- For example, if the value of this field indicates "1", the terminal may perform monitoring of the PDCCH during the subsequent DRX Active Time. (Alternatively, the terminal may start the drx-onDurationTimer during the subsequent DRX occasion. The aforementioned action corresponding to the field value "1" may correspond to the terminal's wake-up action.)

[0200] - Second control information:An indicator indicating the dormancy or active state of a secondary cell (SCell).

[0201] -- It can be composed of an N-bit bitmap, and each bit of the bitmap can correspond to a single secondary cell or a group of secondary cells consisting of multiple secondary cells.

[0202] -- For example, if "0" is indicated as a single bit value of a bitmap, the terminal can set the cell state to sleep for all secondary cells within the secondary cell or secondary cell group pointed to by that bit.

[0203] -- For example, if "1" is indicated as a single bit value of a bitmap, the terminal can set the cell state to an active state for all secondary cells within the secondary cell or secondary cell group pointed to by that bit.

[0204] - Third control information: Indicator that triggers non-periodic CSI (Channel State Information) reporting

[0205] According to one embodiment of the present disclosure, a terminal can monitor a DCI format corresponding to a POSS only in an area that is not the DRX Active Time. More specifically, if a PDCCH monitoring occasion for a POSS configured in the terminal exists in a time area that is not the DRX Active Time, the terminal may determine that the PDCCH monitoring occasion is valid and, accordingly, may perform monitoring of the PDCCH for the POSS at that occasion. If a PDCCH monitoring occasion for a POSS configured in the terminal exists in a time area corresponding to the DRX Active Time, the terminal may determine that the PDCCH monitoring occasion is invalid and, accordingly, may not perform monitoring of the PDCCH for the POSS at that occasion.

[0206] In one embodiment of the present disclosure, the terminal may determine that the PDCCH monitoring occasion for the POSS is invalid under the following circumstances.

[0207] - If the PDCCH monitoring occasion for the configured POSS exists within the DRX Active Time

[0208] - When a collision occurs with another operation of the terminal or a physical channel (or a physical channel with higher priority or related operation) at a time corresponding to the PDCCH monitoring occasion for the configured POSS (e.g., when overlapping with an SS / PBCH block, or when overlapping with a reference signal transmitted or received periodically / semi-permanently (e.g., periodic / semi-permanent CSI-RS / SRS, etc.)

[0209] - When a signal is received to cancel the PDCCH monitoring operation on the PDCCH monitoring occasion for the configured POSS

[0210] According to one embodiment of the present disclosure, if the terminal fails to detect DCI format 3_0 at a PDCCH monitoring occasion for a set POSS, the following operation may be performed.

[0211] - If the terminal has received a fallback operation (or ps-Fallback) from the base station via upper layer signaling, the terminal may perform an operation according to the base station's setting. The base station may set one of the following two operations as a fallback operation for the case where the terminal has not received DCI format 3_0.

[0212] -- 1st operation: Perform monitoring of the PDCCH in the DRX Active Time that exists thereafter.

[0213] -- Second action: Do not perform monitoring of PDCCH in the DRX Active Time that exists thereafter.

[0214] - If the terminal does not receive a countermeasure operation from the base station through upper layer signaling, the terminal may not perform monitoring of the PDCCH during the subsequent DRX Active Time.

[0215] According to one embodiment of the present disclosure, a terminal may be configured to monitor POSS in a Primary Cell (PCell) or a Primary Secondary Cell (PSCell), and may perform monitoring of the POSS based on the configuration information. All or part of the content indicated by the POSS may be applied equally to all secondary cells within the cell group to which the PCell (or PSCell) belongs (i.e., Master Cell Group (MCG) in the case of a PCell, and Secondary Cell Group (SCG) in the case of a PSCell). For example, if the terminal monitors the POSS in the PCell and receives an indicator instructing a wake-up through the received POSS, the terminal may perform a wake-up operation for all primary cells and secondary cells within the MCG; and if the terminal receives an indicator instructing not to wake up, the terminal may not perform a wake-up operation for all primary cells and secondary cells within the MCG. Additionally, if the terminal monitors the POSS in the PSCell and receives an indicator instructing a wake-up via the received POSS, the terminal may perform a wake-up operation for all primary secondary cells and secondary cells within the SCG; and if the terminal receives an indicator instructing not to wake up, the terminal may not perform a wake-up operation for all primary secondary cells and secondary cells within the SCG.

[0216] The terminal can perform monitoring of the POSS to detect the DCI format, and then perform subsequent operations according to the instruction information within the received DCI format. At this time, depending on the time required for the decoding operation of the PDCCH corresponding to the terminal's POSS and the instructions in the DCI, time may be required for preparation or warming up to perform PDCCH monitoring during the subsequent DRX Active Time. Considering this, the monitoring occasion of the POSS can be set to be located a specific time interval earlier than the DRX On or Active Time (or likewise before the terminal starts the drx-onDurationTimer). That is, the PDCCH monitoring occasion for the POSS can be set to exist at a point in time that is a specific offset earlier than the start time of each DRX occasion determined by the DRX cycle. In one example of FIG. 7, the PDCCH monitoring occasion for the POSS is shown to be located with an offset difference of a gap (706) prior to the DRX On.

[0217] Below, various methods are proposed to determine or set the PDCCH monitoring occasion for DCI format 3_0 corresponding to POSS.

[0218] <Example 1-1>

[0219] FIG. 7 is a diagram illustrating an example of a method for setting a PDCCH monitoring occasion for a DCI format 3_0 corresponding to a POSS according to the first-1 embodiment of the present disclosure.

[0220] In some embodiments of the present disclosure, a terminal may receive a search space for a POSS (i.e., a search space for a DCI format 3_0 corresponding to the POSS) from a base station through upper layer signaling. The terminal may receive [search space setting information] described in the first embodiment from the base station. For example, the terminal may receive setting information such as a monitoring duration (704), a slot level monitoring period (705), and an offset (monitoringSlotPeriodicityAndOffset).

[0221] The terminal can determine that a PDCCH monitoring occasion for the POSS exists in each consecutive slot corresponding to the set monitoring length (704) for every set period (705), according to the search space setting information for the POSS. For example, if the period (705) is set to X slot, the offset to Y slot, and the duration (704) to Z slot as the monitoringSlotPeriodicityAndOffset value, the terminal can determine that a PDCCH monitoring occasion exists for a total of Z slots (i.e., {Y, Y+1, Y+2, ..., Y+Z-1}th slots), starting from the Yth slot of the time interval existing for every period of the X slot.

[0222] In some embodiments of the present disclosure, the terminal may receive a ps-offset value (ps-Offset) (702) corresponding to the start time of the PDCCH monitoring occasion for POSS from the start time of the DRX Active Time (707) (or the start time of the DRX ON) via upper layer signaling from the base station. That is, the terminal may determine that the PDCCH monitoring occasion for POSS begins from a point in time corresponding to a time before the ps-offset value (702) relative to the start time of the DRX Active Time (707). The terminal may determine that the PDCCH monitoring occasion exists for a number of slots set as the monitoring length (704) from the start time of the PDCCH monitoring occasion for POSS.

[0223] In some embodiments of the present disclosure, the start time (or start slot) of the PDCCH monitoring occasion for the POSS may be determined by a ps-offset value (702), or by an offset value set by monitoringSlotPeriodicityAndOffset within the search space setting, or by both the ps-offset value (702) and the offset value set by monitoringSlotPeriodicityAndOffset. For example, the start time of the PDCCH monitoring occasion for the POSS may be determined by a method corresponding to at least one or a combination of one or more of the following methods.

[0224] - [Method 1] If the ps-offset value (702) is set and monitoringSlotPeriodicityAndOffset is set, the terminal can ignore the value of monitoringSlotPeriodicityAndOffset and determine the start time of the PDCCH monitoring occasion for POSS using the ps-offset value (702).

[0225] - [Method 2] If the ps-offset value (702) is set and monitoringSlotPeriodicityAndOffset is not set, the terminal can determine the start time of the PDCCH monitoring occasion for POSS using the ps-offset value (702).

[0226] - [Method 3] If the ps-offset value (702) is not set and monitoringSlotPeriodicityAndOffset is set, the terminal can determine the start time of the PDCCH monitoring occasion for POSS with the offset value indicated by monitoringSlotPeriodicityAndOffset.

[0227] - [Method 4] If the ps-offset value (702) is set and monitoringSlotPeriodicityAndOffset is set, the terminal can determine the start time of the PDCCH monitoring occasion for POSS by a combination of the ps-offset value (702) and the offset value indicated by monitoringSlotPeriodicityAndOffset, unlike [Method 1]. For example, the terminal can first determine the PDCCH monitoring occasion of the search space for POSS using the offset value indicated by monitoringSlotPeriodicityAndOffset. Subsequently, among the determined PDCCH monitoring occasions, the terminal can determine the PDCCH monitoring occasion that exists at the closest time, the earliest time, or the latest time among the PDCCH monitoring occasions that exist after the time indicated by the ps-offset value (702) as the start time.

[0228] In some embodiments of the present disclosure, a terminal may receive one or more search spaces for POSS through upper layer signaling from a base station, and may receive a ps-offset value (702) to be applied in each search space, respectively, for each search space. For example, the terminal may receive search space X and search space Y for POSS, and may receive an offset value X to be applied to search space X and an offset value Y to be applied to search space Y, respectively. Accordingly, the terminal may determine the start time of the PDCCH monitoring occasion for POSS for each set of search spaces based on the offset value set for each set of search spaces.

[0229] In some embodiments of the present disclosure, the terminal may receive one or more search spaces for POSS through upper layer signaling from a base station, and may receive one ps-offset value (702) to be applied to all set search spaces. For example, the terminal may receive search spaces X and Y for POSS and one offset value Z. The terminal may determine the start time of the PDCCH monitoring occasion for POSS by applying the offset value Z to both search spaces X and search spaces Y. At this time, the start point of the PDCCH monitoring occasion in search spaces X and Y may be the same (e.g., by applying the aforementioned [Method 1] or [Method 2]) or different (e.g., by applying the aforementioned [Method 3] or [Method 4]).

[0230] In some embodiments of the present disclosure, if the following "condition B" is satisfied, the terminal may consider the monitoring period (705) of the search space for POSS to be the same as the DRX long cycle (drx-LongCycle) (701) set in the terminal. At this time, if the terminal has received a period value for the search space through another setting parameter (e.g., monitoringSlotPeriodicityAndOffset), the terminal may ignore all or part of the setting information indicated by monitoringSlotPeriodicityAndOffset. For example, the terminal may ignore only the slot period information, ignore only the slot offset information, or ignore both the slot period and offset information among the setting information indicated by monitoringSlotPeriodicityAndOffset. At this time, if the unit of the DRX long cycle set in the terminal does not match the unit of the search space monitoring period, the terminal may convert the value to a single standard unit. For example, if X ms is set as the DRX long cycle on the terminal, the terminal can convert X ms into Y slots, which is the slot-unit search space monitoring period. For example, Y = X·2 μ (Slot) (μ is a parameter for the subcarrier interval of the PDCCH, which can be defined as μ=0, 1, 2, 3 for 15, 30, 60, and 120 kHz, respectively). The terminal can use the value of the DRX long cycle, with the unit converted to a slot, as the monitoring period (705) for the POSS. If “Condition B” is not satisfied, the terminal can determine the monitoring period (705) of the search space for the POSS using the original parameter monitoringSlotPeriodicityAndOffset. Here, “Condition B” may be a condition corresponding to at least one of the following conditions or a combination of one or more.

[0231] - When PS-offset (702) is set

[0232] - If monitoringSlotPeriodicityAndOffset is not set

[0233] - When PS-Offset (702) is set and monitoringSlotPeriodicityAndOffset is not set

[0234] - When Power Saving Mode or information having the same or similar effect is set

[0235] The terminal can determine a PDCCH monitoring occasion for POSS according to the first embodiment of the present disclosure described above, and can perform subsequent operations based on the instructions of the DCI format detected after monitoring POSS.

[0236] FIG. 8 is a diagram illustrating an example of a method for setting a PDCCH monitoring occasion for a DCI format 3_0 corresponding to a POSS according to the first-2 and first-3 embodiments of the present disclosure. First, the first-2 embodiment will be described, and then the first-3 embodiment will be described.

[0237] <1-2 Embodiment>

[0238] Referring to FIG. 8, in some embodiments of the present disclosure, a terminal may receive a search space for a POSS (i.e., a search space for a DCI format 3_0 corresponding to the POSS) from a base station through upper layer signaling. The terminal may receive [search space setting information] described in the first embodiment from the base station. For example, the terminal may receive setting information such as a monitoring duration (804), a slot level monitoring period (805), and an offset (monitoringSlotPeriodicityAndOffset).

[0239] In some embodiments of the present disclosure, the terminal may receive a ps-offset value (802) corresponding to the start time of the PDCCH monitoring occasion for POSS from the start time of the DRX Active Time (707) (or the start time of the DRX ON) through upper layer signaling from the base station. That is, the terminal may determine that the PDCCH monitoring occasion for POSS begins from a point in time corresponding to the ps-offset value (802) prior to the start time of the DRX Active Time (807).

[0240] In some embodiments of the present disclosure, the terminal may interpret the monitoring length (804) differently according to a specific condition (referred to as “condition C”). “Condition C” may be a condition corresponding to, for example, at least one or a combination of one or more of the following conditions.

[0241] - ps-offset(702) is set

[0242] - When Power Saving Mode or information having the same or similar effect is set

[0243] If the above condition C is not satisfied, the terminal may interpret and apply the monitoring length (804) according to its original purpose, that is, as described in the duration of the [search space setting information] above. For example, if the period is set to X slot, the offset to Y slot, and the duration to Z slot as the monitoringSlotPeriodicityAndOffset value, the terminal may determine that there is a PDCCH monitoring occasion for a total of Z slots (i.e., the {Y, Y+1, Y+2, ..., Y+Z-1}th slot) starting from the Yth slot of the time interval existing for each period of the X slot. At this time, the value Z that can be set as the duration cannot be set to be greater than or equal to the slot period X set as monitoringSlotPeriodicityAndOffset.

[0244] If the above condition C is satisfied, the terminal may interpret and apply the monitoring length (804) as a time interval during which the terminal performs monitoring of the PDCCH. For example, the terminal may determine the start time of the PDCCH monitoring occasion for the POSS from the ps-offset value (802) set by the base station, determine that the PDCCH monitoring occasions existing in the time interval corresponding to the duration (804) from the start time are valid, and determine that the PDCCH monitoring occasions in the remaining time intervals are invalid. Figure 8 illustrates valid POSS monitoring occasions (808) and invalid POSS monitoring occasions (809). The terminal may perform PDCCH monitoring only for the PDCCH monitoring occasions for the valid POSS. At this time, the value Z, which can be set as the duration, may be set to be greater than or equal to the slot period X set by monitoringSlotPeriodicityAndOffset.

[0245] The terminal can determine a PDCCH monitoring occasion for POSS according to the first and second embodiments of the present disclosure described above, and can perform subsequent operations based on the instructions of the DCI format detected after monitoring POSS.

[0246] <1-3 Embodiments>

[0247] In some embodiments of the present disclosure, a terminal may receive a search space for POSS (i.e., a search space for DCI format 3_0 corresponding to POSS) from a base station through upper layer signaling. The terminal may receive [search space setting information] described in the first embodiment from the base station. For example, the terminal may receive setting information such as a monitoring length (804) and a slot level monitoring period (805) offset (monitoringSlotPeriodicityAndOffset).

[0248] In some embodiments of the present disclosure, the terminal may receive a ps-offset value (802) corresponding to the start time of a PDCCH monitoring occasion for POSS from the start time of the DRX Active Time (807) (or the start time of the DRX ON) through upper layer signaling from the base station. The terminal may determine that PDCCH monitoring occasions existing within a time interval corresponding to the time interval between the time corresponding to the time corresponding to the time corresponding to the gap (806) prior to the start time of the DRX Active Time (807) are valid, and may determine that PDCCH monitoring occasions in the remaining time intervals are invalid. Valid POSS monitoring occasions (808) and invalid POSS monitoring occasions (809) are illustrated in FIG. 8. That is, the terminal may determine that only PDCCH monitoring occasions existing within a time interval corresponding to the monitoring length (804) in FIG. 8 are valid. At this time, the gap (806) can be determined based on the capability reported by the terminal to the base station.

[0249] In addition, the aforementioned first embodiment, first-1 embodiment, first-2 embodiment, and first-3 embodiment may be implemented in combination with each other.

[0250] <Second Embodiment>

[0251] According to one embodiment of the present disclosure, a terminal may receive an indicator from a base station via L1 signaling indicating a dormancy or active state for a secondary cell. When the secondary cell is in a dormancy state, the terminal may not perform PDCCH monitoring for the secondary cell (or may perform PDCCH monitoring intermittently), and may continuously perform operations such as channel state measurement (CSI measurement), Adaptive Gain Control (AGC), and beam management.

[0252] According to one embodiment of the present disclosure, a terminal may receive an indicator from a base station via a POSS indicating a sleep state or an active state for the aforementioned secondary cell. More specifically, a DCI format corresponding to the POSS (e.g., DCI format 3_0) may include, for example, the following control information.

[0253] - 1st control information: An indicator that controls the PDCCH monitoring behavior at a DRX occasion that follows a POSS monitoring occasion (or may be expressed as an indicator indicating wake-up status, or ps-Index, etc.).

[0254] -- For example, if the value of this field indicates "0", the terminal may not perform monitoring of the PDCCH during subsequent DRX Active Time. (Alternatively, the terminal may not start the drx-onDurationTimer during subsequent DRX occasions. The aforementioned behavior corresponding to a field value of "0" may correspond to the terminal not waking up behavior.)

[0255] -- For example, if the value of this field indicates "1", the terminal may perform monitoring of the PDCCH during the subsequent DRX Active Time. (Alternatively, the terminal may start the drx-onDurationTimer during the subsequent DRX occasion. The aforementioned action corresponding to the field value "1" may correspond to the terminal's wake-up action.)

[0256] - Second control information: An indicator indicating the dormancy or active state of a secondary cell (SCell).

[0257] -- It can be composed of an N-bit bitmap, and each bit of the bitmap can correspond to a single secondary cell or a group of secondary cells consisting of multiple secondary cells.

[0258] -- For example, if "0" is indicated as a single bit value of a bitmap, the terminal can set the cell state to sleep for all secondary cells within the secondary cell or secondary cell group pointed to by that bit.

[0259] -- For example, if "1" is indicated as a single bit value of a bitmap, the terminal can set the cell state to an active state for all secondary cells within the secondary cell or secondary cell group pointed to by that bit.

[0260] - Third control information:Indicator that triggers non-periodic CSI (Channel State Information) reporting

[0261] According to one embodiment of the present disclosure, a terminal may be configured to monitor POSS in a Primary Cell (PCell) or a Primary Secondary Cell (PSCell), and may perform monitoring of the POSS based on the configuration information. All or part of the content indicated by the POSS may be applied equally to all secondary cells within the cell group to which the PCell (or PSCell) belongs (i.e., Master Cell Group (MCG) in the case of a PCell, and Secondary Cell Group (SCG) in the case of a PSCell). For example, if the terminal monitors the POSS in the PCell and receives an indicator instructing a wake-up through the received POSS, the terminal may perform a wake-up operation for all primary cells and secondary cells within the MCG; and if the terminal receives an indicator instructing not to wake up, the terminal may not perform a wake-up operation for all primary cells and secondary cells within the MCG. Additionally, if the terminal monitors the POSS in the PSCell and receives an indicator instructing a wake-up via the received POSS, the terminal may perform a wake-up operation for all primary secondary cells and secondary cells within the SCG; and if the terminal receives an indicator instructing not to wake up, the terminal may not perform a wake-up operation for all primary secondary cells and secondary cells within the SCG.

[0262] As described above, the terminal can receive both an indicator indicating whether it is woke up ("first control information") and an indicator indicating the sleep state of a secondary cell ("second control information") through a DCI format corresponding to POSS. In this case, both the indicator indicating whether it is woke up and the indicator indicating the sleep state of a secondary cell correspond to indicators that control the terminal's PDCCH monitoring operation. Therefore, the operation of the terminal can be controlled according to a specific combination of information indicated by the first control information and the second control information. Below, terminal operation based on a combination of the contents of each field within the POSS DCI format is specifically proposed.

[0263] 1) 1st control information: Wake-up instruction, 2nd control information: Cell or cell group indicated as active state

[0264] - The terminal can perform a state change to the active state for secondary cells indicated as active state.

[0265] - The terminal can perform a wake-up operation (i.e., an operation to monitor the PDCCH in the subsequent DRX Active Time or an operation to start drx-onDurationTimer) for the cells indicated as active among the cells in the cell group to which the primary cell that received the POSS belongs.

[0266] 2) 1st Control Information: Wake-up instruction, 2nd Control Information: Cell or cell group instructed to enter sleep state

[0267] - The terminal can perform a state change to sleep state for secondary cells designated as sleep state.

[0268] - The terminal may perform at least one or more of the following operations for cells designated as being in a dormant state among the cells within the cell group to which the primary cell that received the POSS belongs.

[0269] -- Operation 1) For a cell indicated as being in a sleep state, the terminal may still consider the drx-onDurationTimer to have started and the MAC Entity to be in the DRX Active Time. In this case, the terminal may not perform monitoring of the PDCCH during the corresponding DRX Active Time, and all other operations (e.g., periodic / semi-permanent CSI reporting operations, periodic / semi-permanent SRS transmission operations) other than the PDCCH monitoring that the terminal must perform during the DRX Active Time may be performed as before.

[0270] -- Operation 2) For a cell indicated as being in a dormant state, the terminal may consider the MAC entity not to correspond to DRX Active Time. Therefore, the terminal may not perform PDCCH monitoring, and furthermore, the terminal may not perform all other operations required to be performed during DRX Active Time (e.g., periodic / semi-permanent CSI reporting operations, periodic / semi-permanent SRS transmission operations).

[0271] 3) 1st control information: Instruct not to wake up, 2nd control information: Cell or group of cells instructed to be active

[0272] - The terminal can perform a state change to the active state for secondary cells indicated as active state.

[0273] - The terminal may perform at least one or more of the following operations for the cells indicated as being in an active state among the cells within the cell group to which the primary cell that received the POSS belongs.

[0274] -- Operation 1) The terminal may not expect the first control information to indicate that it will not wake up and the second control information to indicate that it will be active. Therefore, if it receives such an unexpected combination of control information, the terminal may consider the contents of the corresponding DCI format as an error and may operate according to a selected default operation. Here, the default operation may correspond to an operation that can be applied, for example, when the terminal fails to decode the DCI format corresponding to POSS (refer to the operation in the case where the terminal does not detect DCI format 3_0 in the first embodiment). That is, if the first control information indicates that it will not wake up, the second control information may always indicate that all cells will be in a sleep state. That is, if the first control information indicates that it will not wake up, the terminal may expect that the second control information will always indicate that all cells will be in a sleep state.

[0275] -- Operation 2) The terminal may consider that the MAC entity does not correspond to DRX Active Time for a cell indicated as active, and accordingly, may not perform monitoring for PDCCH in that cell.

[0276] -- Operation 3) If there is at least one cell indicated as active by the second control information, the terminal may start drx-onDurationTimer. However, the terminal may not perform PDCCH monitoring for the primary cell (or primary secondary cell) that received POSS and for the cells indicated as dormant, and may perform PDCCH monitoring only for the cells indicated as active. The terminal may transmit and receive information to and from the cells indicated as active using the control channel and the data channel. The terminal may transmit information to the corresponding active cell or to the primary cell (primary secondary cell or secondary cell configured to transmit PUCCH) via the PUCCH (Physical Uplink Control Channel).

[0277] -- Operation 4) If there is at least one cell indicated as active state as second control information, the terminal may start drx-onDurationTimer. The terminal may monitor PDCCH in DRX Active Time for the primary cell (or primary secondary cell) that received POSS and the cells indicated as active state, and may not perform monitoring of PDCCH for the cells indicated as dormant state.

[0278] -- Operation 5) If the first control information indicates that the device should not wake up, the second control information may be reinterpreted as other control information. For example, the second control information may be reinterpreted as an indicator that triggers a channel status report or SRS transmission. More specifically, the second control information may be reinterpreted as follows.

[0279] --- The second control information is reinterpreted as the second-first control information indicating the following content

[0280] ---- 2-1 The control information may be composed of an N-bit bitmap, and each bit of the bitmap may correspond to one secondary cell or a group of secondary cells consisting of multiple secondary cells.

[0281] For example, if "0" is indicated as a bit value of a bitmap, the terminal may not perform channel status reporting or SRS transmission for all secondary cells in the secondary cell or secondary cell group indicated by that bit.

[0282] For example, if "1" is indicated as a bit value of a bitmap, the terminal can perform channel status reporting or SRS transmission for all secondary cells in the secondary cell or secondary cell group indicated by that bit.

[0283] Parameters for channel status reporting or SRS transmission can be set in advance through upper-layer signaling, and channel status reporting can be performed through pre-configured PUCCH or PUSCH.

[0284] In addition, if the terminal has instructed that the first control information not wake up, it may perform a state change to a sleep state for all secondary cells within the cell group.

[0285] 4) 1st Control Information: Instruct not to wake up, 2nd Control Information: Cell or cell group instructed to enter sleep state

[0286] - The terminal can perform a state change to sleep state for secondary cells designated as sleep state.

[0287] - The terminal may not perform a wake-up operation (i.e., an operation to monitor PDCCH in the subsequent DRX Active Time or an operation to start drx-onDurationTimer) for cells designated as being in a sleep state among the cells in the cell group to which the primary cell that received the POSS belongs.

[0288] According to one embodiment of the present disclosure, which of the aforementioned terminal operations to follow may be pre-set. That is, a base station may pre-set to the terminal whether to perform which of the aforementioned operations through upper-layer signaling, and the terminal may control subsequent operations based on the base station's setting information.

[0289] According to one embodiment of the present disclosure, the aforementioned terminal operation may vary depending on the capability of the terminal. That is, the terminal may report its capability regarding the operations it can perform to the base station, and the base station may appropriately control the operation of the terminal based on the capability report received from the terminal.

[0290] <2-1 Embodiment>

[0291] According to one embodiment of the present disclosure, if the terminal performs blind decoding for DCI format 3_0 corresponding to the POSS at a PDCCH monitoring occasion for the configured POSS but fails to detect DCI format 3_0, or if the PDCCH monitoring occasion for the POSS configured in the terminal is invalid and fails to detect DCI format 3_0, the terminal may perform the following operations.

[0292] - If the terminal has received a fallback operation (or ps-Fallback) from the base station via upper layer signaling, the terminal may perform an operation according to the base station's setting. The base station may set one of the following two operations as a fallback operation for the case where the terminal has not received DCI format 3_0.

[0293] -- 1st operation: Perform monitoring of the PDCCH in the DRX Active Time that exists thereafter.

[0294] -- Second action: Do not perform monitoring of PDCCH in the DRX Active Time that exists thereafter.

[0295] - If the terminal does not receive a countermeasure operation from the base station through upper layer signaling, the terminal may not perform monitoring of the PDCCH during the subsequent DRX Active Time.

[0296] According to one embodiment of the present disclosure, a terminal may perform blind decoding on a DCI at a PDCCH monitoring occasion where a DCI format including an indicator indicating a sleep state or active state for a secondary cell may be transmitted from a base station, but fail to detect the DCI, or fail to detect DCI format 3_0 because the PDCCH monitoring occasion for the POSS set on the terminal is invalid. In this case, the terminal needs to define a fallback operation to determine the sleep state or active state of the secondary cells. A specific embodiment thereof is proposed below.

[0297] <Example 2-1-1>

[0298] In the 2-1-1 embodiment of the present disclosure, if the terminal does not detect a DCI format indicating whether a secondary cell (or secondary cell group) is in a dormant state or active state from the base station, the terminal may follow an action corresponding to at least one or a combination of one or more of the following countermeasure actions.

[0299] - Operation A) The terminal can change the corresponding secondary cell(s) to an active state.

[0300] - Operation B) The terminal can change the corresponding secondary cell(s) to a sleep state.

[0301] - Operation C) The terminal may receive a countermeasure mode operation setting from the base station via upper layer signaling. For example, the base station may pre-set whether the terminal will operate as the aforementioned Operation A or the aforementioned Operation B via upper layer signaling, and the terminal may operate in the set countermeasure mode. If the terminal is set to Operation A, the terminal may change the secondary cell(s) to an active state if it fails to detect a DCI format indicating whether the secondary cell(s) are in a sleep state or an active state. If the terminal is set to Operation B, the terminal may change the secondary cell(s) to a sleep state if it fails to detect a DCI format indicating whether the secondary cell(s) are in a sleep state or an active state. If the terminal does not receive a setting for the countermeasure mode, the terminal's countermeasure mode operation may be fixed to Operation A or Operation B.

[0302] - Operation D) The terminal can maintain a state identical to the most recent state of the corresponding secondary cell(s).

[0303] <Example 2-1-2>

[0304] In the 2-1-2 embodiment of the present disclosure, the countermeasure operation of the terminal may be controlled differently depending on whether the DCI format indicating whether the secondary cell (or secondary cell group) is in a dormant or active state is monitored in DRX Active Time or DRX Inactive Time, or depending on which DCI format is indicated. For convenience of explanation, the following conditions are described in advance.

[0305] [Condition D]

[0306] A DCI format indicating whether a cell (or secondary cell group) is in a dormant or active state,

[0307] - If it corresponds to a DCI format monitored in an area other than DRX Active Time

[0308] - If it corresponds to the DCI format indicating whether to monitor PDCCH (DCI format corresponding to the aforementioned POSS)

[0309] - If it corresponds to a DCI format not for scheduling purposes

[0310] [Condition E]

[0311] A DCI format indicating whether a cell (or secondary cell group) is in a dormant or active state,

[0312] - If it corresponds to the DCI format monitored in DRX Active Time

[0313] - If it corresponds to a DCI format other than the DCI format indicating whether to monitor PDCCH (the DCI format corresponding to the aforementioned POSS)

[0314] - If it corresponds to a DCI format for scheduling purposes (e.g., DCI format 0_1 / 1_1)

[0315] If the terminal fails to detect a DCI format containing an indicator indicating a dormant or active state for a secondary cell satisfying all or part of [Condition D], the terminal may perform a "first countermeasure" operation. The "first countermeasure" operation may follow an operation corresponding to at least one or a combination of one or more of the following operations.

[0316] - Operation 1) The terminal may determine the "first countermeasure" operation based on configuration information regarding the terminal's countermeasure operation in the event that it fails to detect the DCI format 3_0 corresponding to POSS. As an example, it may follow the following operation.

[0317] -- If the terminal is configured with "1st action: perform monitoring of PDCCH in the subsequent DRX Active Time" as a countermeasure action for the case where the terminal fails to receive DCI format 3_0, the terminal may perform the action of changing the corresponding secondary cell(s) to an active state as the "1st countermeasure" action. If the terminal is configured with "2nd action: do not perform monitoring of PDCCH in the subsequent DRX Active Time" as a countermeasure action for the case where the terminal fails to receive DCI format 3_0, the terminal may perform the action of changing the corresponding secondary cell(s) to an inactive state as the "1st countermeasure" action.

[0318] -- If the terminal has not received a countermeasure operation for the case where it has not received DCI format 3_0, the terminal may perform an operation to change the corresponding secondary cell(s) to an active state.

[0319] - Operation 2) The terminal may follow at least one of Operation A, Operation B, Operation C, or Operation D of <Embodiment 2-1-1> as a "first countermeasure" operation.

[0320] If the terminal fails to detect a DCI format containing an indicator indicating a sleep state or an active state for a secondary cell satisfying all or part of [Condition E], the terminal may perform a "second countermeasure" operation. The "second countermeasure" operation may follow an operation corresponding to at least one or a combination of one or more of the following operations.

[0321] - Operation 1) The terminal can maintain a state identical to the most recent state of the corresponding secondary cell(s).

[0322] - Operation 2) The terminal may follow at least one of operation A, operation B, or operation C of <Embodiment 2-1-1> as a "first countermeasure" operation.

[0323] In addition, the aforementioned second embodiment, 2-1 embodiment, 2-1-1 embodiment, and 2-1-2 embodiment may be implemented in combination with each other. Of course, the aforementioned first embodiment, 1-1 embodiment, 1-2 embodiment, and 1-3 embodiment, and the aforementioned second embodiment, 2-1 embodiment, 2-1-1 embodiment, and 2-1-2 embodiment may also be implemented in combination with each other.

[0324] FIG. 9 is a flowchart illustrating a method for saving power of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0325] Referring to FIG. 9, in step 910, the base station (901) can transmit POSS setting information to the terminal (902). By transmitting POSS setting information to the terminal (902), the base station (901) can set up WUS monitoring operations. In one embodiment of the present disclosure, the base station (901) can provide WUS setting information to the terminal (902) through upper layer signaling. In one embodiment of the present disclosure, the POSS setting information may include a search space for the POSS, a POSS start offset, etc.

[0326] In step 920, the terminal (902) can monitor the PDCCH for the POSS based on POSS setting information. More specifically, the terminal (902) can monitor the PDCCH for the POSS at a specific time interval during which the POSS can be received, based on POSS setting information.

[0327] In step 930, the terminal (902) can receive POSS (or a DCI format corresponding to POSS) from the base station (901) through the downlink control channel. That is, the terminal (902) can detect a DCI format corresponding to POSS while monitoring the PDCCH based on the POSS setting information in step 920.

[0328] In step 940, the terminal (902) can perform subsequent operations based on the content instructed in the DCI format corresponding to the received POSS. For example, the terminal can perform PDCCH monitoring operations in DRX Active Time and state change operations for secondary cells.

[0329] A transceiver, memory, and processor of a terminal and a base station for carrying out the embodiments described above of the present disclosure are illustrated in FIG. 10 and FIG. 11, respectively. In order to carry out the POSS transmission and reception method described above, the PDCCH monitoring control method according to the same, and the data transmission and reception operation according to the same, the transceiver, memory, and processor of the base station and the terminal can each operate according to the embodiments described above.

[0330] FIG. 10 is a block diagram illustrating the structure of a terminal according to one embodiment of the present disclosure.

[0331] Referring to FIG. 10, the terminal may include a transceiver (1010), a memory (2220), and a processor (1030). However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. In addition, at least some or all of the transceiver (1010), the memory (1020), and the processor (1030) may be implemented in the form of a single chip.

[0332] In one embodiment, the transceiver (1010) can transmit and receive signals with a base station. The above-described signal may include control information and data. To this end, the transceiver (1010) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. Additionally, the transceiver (1010) can receive a signal through a wireless channel and output it to a processor (1030), and transmit the signal output from the processor (1030) through a wireless channel.

[0333] In one embodiment, the memory (1020) may store programs and data necessary for the operation of the terminal. Additionally, the memory (1020) may store control information or data included in signals transmitted and received by the terminal. The memory (1020) may be composed of a storage medium or a combination of storage media such as ROM, RAM, a hard disk, CD-ROM, and DVD. Additionally, the memory (602) may be composed of multiple memories. According to one embodiment, the memory (602) may store a program for executing an operation for power saving of the terminal.

[0334] In one embodiment, the processor (1030) can control a series of processes that allow the terminal to operate according to the embodiments of the present disclosure described above. In one embodiment, the processor (1030) can receive WU configuration information from a base station by executing a program stored in memory (1020), monitor a Physical Downlink Control Channel (PDCCH) based on POSS configuration information, receive POSS from the base station through the downlink control channel, and control the terminal to wake up based on the POSS.

[0335] FIG. 11 is a block diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0336] Referring to FIG. 11, the base station may include a transceiver (1110), a memory (1120), and a processor (1130). However, the components of the base station are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. In addition, the transceiver (1110), the memory (1120), and the processor (1130) may be implemented in the form of a single chip.

[0337] In one embodiment, the transceiver (1110) can transmit and receive signals with a terminal. The above-described signal may include control information and data. To this end, the transceiver (1110) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. Additionally, the transceiver (1110) may receive a signal through a wireless channel and output it to a processor (1130), and transmit the signal output from the processor (1130) through a wireless channel.

[0338] In one embodiment, the memory (1120) may store programs and data necessary for the operation of the terminal. Additionally, the memory (1120) may store control information or data included in signals transmitted and received by the terminal. The memory (1120) may be composed of a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, the memory (1120) may be composed of multiple memories. According to one embodiment, the memory (1120) may store a program for executing an operation for power saving of the terminal.

[0339] In one embodiment, the processor (1130) can control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. In one embodiment, the processor (1130) can control the transmission of POSS setting information to a terminal by executing a program stored in memory (1120), the transmission of POSS to a terminal via a downlink control channel based on the POSS setting information, and the transmission of control information to a terminal via a downlink control channel based on the POSS.

[0340] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0341] When implemented in software, a computer-readable storage medium or computer program product storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium or computer program product are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure.

[0342] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), magnetic disc storage devices, CD-ROM (Compact Disc-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0343] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0344] In the specific embodiments of the present disclosure described above, the components included in the present disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0345] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated together as needed. For example, parts of one embodiment of the present disclosure and another embodiment may be combined to operate a base station and a terminal. In addition, the embodiments of the present disclosure are applicable to other communication systems, and other variations based on the technical concept of the embodiments may also be possible. For example, the embodiments may be applied to LTE systems, 5G or NR systems, etc.

Claims

Claim 1 A method performed by a terminal in a wireless communication system comprises: receiving a radio resource control (RRC) message from a base station containing power saving offset information indicating a time for the terminal to start monitoring a physical downlink control channel (PDCCH) for detecting downlink control information (DCI) associated with power saving prior to the start of drx-onDurationTimer; and monitoring the PDCCH for detecting the DCI associated with power saving based on the RRC message. A method comprising the step of detecting the DCI associated with the power saving, wherein the DCI includes wake-up instruction information and dormancy instruction information for a secondary cell (Scell), and the wake-up instruction information indicates whether to start the drx-onDurationTimer for the next discontinuous reception (DRX) cycle, and when the wake-up instruction information indicates to start the drx-onDurationTimer for the next DRX cycle and the dormancy instruction information indicates the cell state of the Scell ​​as a dormancy state, a PDCCH monitoring operation for the Scell ​​is not performed during the DRX active time. Claim 2 A method according to claim 1, wherein the RRC message further includes search space information for monitoring the PDCCH for detecting the DCI. Claim 3 A method according to claim 2, wherein the search space information includes parameters indicating periodicity and offset for monitoring the PDCCH for detecting the DCI. Claim 4 A method according to claim 2, wherein the search space information includes a parameter indicating the number of consecutive slots in which the search space exists. Claim 5 A method according to claim 2, further comprising the step of identifying at least one PDCCH monitoring occasion for the DCI based on the power saving offset information and the search space information. Claim 6 In claim 5, the method wherein the at least one PDCCH monitoring occasion is located earlier by a preset time gap from the point in time of the drx-onDurationTimer. Claim 7 In a terminal of a wireless communication system, a transceiver; and includes at least one processor, wherein the at least one processor receives a radio resource control (RRC) message from a base station containing power saving offset information indicating a time for the terminal to start monitoring a physical downlink control channel (PDCCH) for detecting downlink control information (DCI) associated with power saving prior to the start of the drx-onDurationTimer, and based on the RRC message, monitors the PDCCH for detecting the DCI associated with power saving, and detects the DCI associated with power saving, wherein the DCI includes wake-up instruction information and dormancy instruction information for a secondary cell (Scell), the wake-up instruction information indicates whether to start the drx-onDurationTimer for the next discontinuous reception (DRX) cycle, the wake-up instruction information indicates to start the drx-onDurationTimer for the next DRX cycle, and the dormancy instruction information A terminal in which PDCCH monitoring operation for said Scell ​​is not performed during the DRX active time when the cell state of the Scell ​​is indicated as dormancy state. Claim 8 In claim 7, the RRC message further comprises search space information for monitoring the PDCCH for detecting the DCI. Claim 9 In claim 8, the search space information comprises a terminal including parameters indicating periodicity and offset for monitoring the PDCCH for detecting the DCI. Claim 10 In claim 8, the search space information comprises a terminal including a parameter indicating the number of consecutive slots in which the search space exists. Claim 11 In claim 8, the terminal, wherein the at least one processor identifies at least one PDCCH monitoring occasion for the DCI based on the power saving offset information and the search space information. Claim 12 In claim 11, the at least one PDCCH monitoring occasion is a terminal located earlier by a preset time gap from the point in time of the drx-onDurationTimer.

Images