Method for receiving downlink signal, user equipment, processing device, storage medium, method for transmitting downlink signal, and base station

Abstract

In a first mode, a common downlink signal of a first cell may be transmitted / monitored on the first cell in a first period. A configuration related to a second mode may be provided that includes cell information about a second cell associated with the first cell. Based on switching from the first mode to the second mode, a common downlink signal of the first cell may be transmitted / monitored on the second cell for a first duration.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system. Background Art

[0002] Various technologies such as machine-to-machine (M2M) communication, machine-type communication (MTC), and various devices requiring high data throughput (e.g., smart phones and tablet personal computers (PCs)) have emerged and become popular. Therefore, the data throughput required to be processed in cellular networks has increased rapidly. In order to meet this rapidly increasing data throughput, carrier aggregation technology or cognitive radio technology for effectively using more frequency bands and multiple input multiple output (MIMO) technology or multiple base station (BS) cooperation technology for increasing the data capacity transmitted on limited frequency resources have been developed.

[0003] As more and more communication devices require greater communication capacity, enhanced mobile broadband (eMBB) communication is needed relative to traditional radio access technology (RAT). In addition, massive machine type communication (mMTC), which provides various services anytime and anywhere by connecting multiple devices and objects to each other, is a major issue to be considered in next-generation communications.

[0004] Discussions are also underway to design communication systems that take into account services / user equipment (UE) that are sensitive to reliability and latency. Discussions are also underway to introduce next generation RATs that take into account eMBB communications, mMTC, ultra-reliable low latency communications (URLLC), etc. Summary of the invention

[0005] Technical issues

[0006] As the number of services / user equipments (UEs) that a network needs to support increases rapidly, there is an increasing demand for not only UE power saving but also network power saving.

[0007] One object of the present disclosure is to provide a method and process for network energy saving.

[0008] Another object of the present disclosure is to provide a method and process for sending a downlink signal to achieve network energy saving.

[0009] Another object of the present disclosure is to provide a method and process for sending minimum system information to achieve network energy saving.

[0010] Another object of the present disclosure is to provide an energy saving method and process for a network, a base station (BS) and / or a user equipment (UE) by reducing the transmission of common signals / channels such as synchronization signal blocks (SSBs), system information block 1 (SIB1), other system information (SI) and / or paging or adjusting their periodicity.

[0011] The objects to be achieved by using the present disclosure are not limited to those specifically described above, and other objects not described herein will be more clearly understood by those skilled in the art from the following detailed description.

[0012] Technical Solution

[0013] In one aspect of the present disclosure, a method for receiving a downlink signal by a user equipment (UE) in a wireless communication system is provided. The method may include the following steps: monitoring a common downlink signal of a first cell on a first cell in a first mode with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and monitoring a common downlink signal of the first cell on the second cell within a first time period based on a transition from the first mode to the second mode.

[0014] In another aspect of the present disclosure, a UE configured to receive a downlink signal in a wireless communication system is provided. The UE may include: at least one transceiver; at least one processor; and at least one computer memory, which is operatively connected to the at least one processor and configured to store instructions, which, when executed, cause the at least one processor to perform operations. The operations may include: monitoring a common downlink signal of a first cell on a first cell in a first mode with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and monitoring a common downlink signal of the first cell on the second cell within a first time period based on a transition from the first mode to the second mode.

[0015] In another aspect of the present disclosure, a processing device in a wireless communication system is provided. The processing device may include: at least one processor; and

[0016] At least one computer memory is operatively connected to at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations. The operations may include: monitoring a common downlink signal of a first cell on a first cell in a first mode with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and monitoring a common downlink signal of the first cell on the second cell within a first time period based on a transition from the first mode to the second mode.

[0017] In another aspect of the present disclosure, a computer-readable storage medium is provided. The storage medium may be configured to store at least one program code including instructions, which, when executed, cause at least one processor to perform an operation. The operation:

[0018] In another aspect of the present disclosure, a method for transmitting a downlink signal by a base station (BS) to a UE in a wireless communication system is provided. The method may include the following steps: transmitting a common downlink signal of a first cell in a first mode on a first cell with a first periodicity; transmitting a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and transmitting a common downlink signal of the first cell in the second cell within a first time period based on a transition from the first mode to the second mode.

[0019] In another aspect of the present disclosure, a BS configured to send a downlink signal to a UE in a wireless communication system is provided. The BS may include: at least one transceiver; at least one processor; and at least one computer memory, which is operatively connected to the at least one processor and configured to store instructions, which, when executed, cause the at least one processor to perform operations. The operations may include: sending a common downlink signal of a first cell on a first cell in a first mode with a first periodicity; sending a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and sending a common downlink signal of the first cell on the second cell within a first time period based on a transition from the first mode to the second mode.

[0020] In various aspects of the present disclosure, the common downlink signal of the first cell may be system information of the first cell.

[0021] In various aspects of the present disclosure, the common downlink signal of the first cell may be a paging message.

[0022] In various aspects of the present disclosure, the common downlink signal of the first cell may be a synchronization signal block (SSB) consisting of a primary synchronization signal (PSS) of the first cell, a secondary synchronization signal (SSS) of the first cell, and a physical broadcast channel (PBCH) of the first cell.

[0023] In various aspects of the present disclosure, the method of the UE or the operation of the UE, the processing device or the storage medium may include: detecting a group common downlink control information (DCI) format related to the transition to the second mode; and transitioning from the first mode to the second mode based on the group common DCI format.

[0024] In various aspects of the present disclosure, the method of the UE or the operation of the UE, the processing device, or the storage medium may further include sending an acknowledgement (ACK) or a negative ACK (NACK) for transitioning to the second mode based on the group common DCI format.

[0025] In various aspects of the present disclosure, the method of the UE or the operation of the UE, the processing device or the storage medium may include: receiving a configuration related to the third mode, wherein the configuration related to the third mode includes information about a time period for the third mode; based on the transition from the first mode to the third mode, monitoring the physical downlink control channel (PDCCH) of the system information block 1 (SIB1) for the first cell on the first cell within a second time period; based on detecting the SIB1 PDCCH for SIB1, sending a SIB1 request on a random access channel (RACH) resource related to the SIB1 PDCCH; and based on the transmission of the SIB1 request, receiving a physical downlink shared channel (PDSCH) carrying SIB1.

[0026] In various aspects of the present disclosure, the method of the BS or the operation of the BS may further include transmitting a group common DCI format related to the transition to the second mode.

[0027] In various aspects of the present disclosure, a method of a BS or an operation of a BS may include transitioning from a first mode to a second mode based on transmission of a group common DCI format.

[0028] In various aspects of the present disclosure, the method of the BS or the operation of the BS may further include receiving an ACK or a NACK for transitioning to the second mode based on the group common DCI format.

[0029] In various aspects of the present disclosure, the method of the BS or the operation of the BS may include: sending a configuration related to a third mode related to the first cell, wherein the configuration related to the third mode includes information about a time period for the third mode; based on the transition from the first mode to the third mode, sending a PDCCH for SIB1 of the first cell on the first cell within a second time period; and based on receiving a SIB1 request on a RACH resource related to the PDCCH for SIB1, sending a PDSCH carrying SIB1.

[0030] In various aspects of the present disclosure, the information about the time period for the second mode may include configuration for a plurality of time periods.The group common DCI format may include information about a first time period among the plurality of time periods.

[0031] The above solutions are only some examples of the present disclosure, and those skilled in the art can deduce and understand various examples into which the technical features of the present disclosure are incorporated from the following detailed description.

[0032] Beneficial Effects

[0033] According to implementations of the present disclosure, energy saving methods and processes for a network, a base station (BS) and / or a user equipment (UE) may be provided.

[0034] According to an implementation of the present disclosure, a method and process for transmitting a downlink signal may be provided to achieve energy saving of a network, a BS and / or a UE.

[0035] According to an implementation of the present disclosure, a method and process for sending minimum system information may be provided to achieve energy saving of a network, a BS and / or a UE.

[0036] Effects according to the present disclosure are not limited to those specifically described above, and other effects not described herein will be more clearly understood by those skilled in the art to which the present disclosure relates from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are included to provide a further understanding of the present disclosure, and illustrate examples of implementations of the present disclosure and together with the detailed description serve to explain the implementations of the present disclosure:

[0038] Figure 1 An example of a communication system 1 to which an implementation of the present disclosure is applied is shown;

[0039] Figure 2 is a block diagram illustrating an example of a communication device capable of executing the method according to the present disclosure;

[0040] Figure 3 Another example of a wireless device capable of performing implementations of the present disclosure is shown;

[0041] Figure 4 An example of a frame structure used in a wireless communication system based on the 3rd Generation Partnership Project (3GPP) is shown;

[0042] Figure 5 a resource grid showing time slots;

[0043] Figure 6 Showing physical channels in a 3rd Generation Partnership Project (3GPP)-based communication system as an exemplary wireless communication system and a signal transmission / reception process using the physical channels;

[0044] Figure 7 Shows the system information (SI) acquisition process;

[0045] Figure 8 A random access procedure applicable to an implementation of the present disclosure is shown;

[0046] Fig. 9An example of physical downlink shared channel (PDSCH) time domain resource assignment (TDRA) over a physical downlink control channel (PDCCH) and an example of physical uplink shared channel (PUSCH) TDRA over the PDCCH are shown;

[0047] Fig.10

[0048] Fig.11 illustrates discontinuous reception (DRX) operations suitable for implementations of the present disclosure;

[0049] Fig.12 The configuration of a long DRX cycle and a short DRX cycle is shown;

[0050] Fig.13 shows the transmission of system information block 1 (SIB1) in a 3GPP based system;

[0051] Fig.14 The process of sending or receiving a common signal / channel according to some implementations of the present disclosure is shown;

[0052] Fig.15 shows common signal / channel opportunities for cells according to some implementations of the present disclosure;

[0053] Fig.16 A flow chart showing a downlink (DL) signal reception process by a user equipment (UE) according to some implementations of the present disclosure; and

[0054] Fig.17 A flow of DL signal transmission by a base station (BS) according to some implementations of the present disclosure is shown. DETAILED DESCRIPTION

[0055] Hereinafter, implementations according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description given below with reference to the accompanying drawings is intended to illustrate exemplary implementations of the present disclosure, rather than to show the only implementations that can be implemented according to the present disclosure. The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be practiced without these specific details.

[0056] In some cases, known structures and devices may be omitted or may be shown in block diagram form, thereby focusing on important features of the structures and devices so as not to obscure the concepts of the present disclosure. The same reference numerals will be used throughout the present disclosure to refer to the same or similar parts.

[0057] The following techniques, devices and systems can be applied to various wireless multiple access systems. For example, multiple access systems may include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, multi-carrier frequency division multiple access (MC-FDMA) systems, etc. CDMA can be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented by radio technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Enhanced Data Rate for GSM Evolution (EDGE) (i.e., GERAN), etc. OFDMA can be specifically implemented by radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE 802.20, Evolved UTRA (E-UTRA), etc. UTRA is part of Universal Mobile Telecommunications System (UMTS), and 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of E-UMTS using E-UTRA. 3GPP LTE adopts OFDMA on downlink (DL) and SC-FDMA on uplink (UL). LTE-advanced (LTE-A) is an evolved version of 3GPP LTE.

[0058] For the convenience of description, the description will be given under the assumption that the present disclosure is applied to LTE and / or new RAT (NR). However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP LTE / NR system, the mobile communication system is applicable to any other mobile communication system except for matters specific to the 3GPP LTE / NR system.

[0059] For terms and techniques used in the present disclosure that are not described in detail, reference may be made to standard specifications based on 3GPP (for example, 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, 3GPP TS 36.300, 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.214, 3GPP TS 38.300, 3GPP TS 38.304, 3GPP TS 38.331, etc.).

[0060] In an example of the present disclosure described later, if a device "assumes" something, this may mean that a channel transmission entity transmits a channel in accordance with the corresponding "assumption". This may also mean that a channel reception entity receives or decodes a channel in a form that conforms to the "assumption" under the premise that the channel is transmitted in accordance with the "assumption".

[0061] In the present disclosure, a user equipment (UE) may be fixed or mobile. Each of the various devices that transmit and / or receive user data and / or control information by communicating with a base station (BS) may be a UE. The term UE may be referred to as a terminal device, a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a personal digital assistant (PDA), a wireless modem, a handheld device, etc. In the present disclosure, a BS refers to a fixed station that communicates with a UE and / or another BS and exchanges data and control information with the UE and another BS. The term BS may be referred to as an advanced base station (ABS), a node B (NB), an evolved node B (eNB), a base transceiver system (BTS), an access point (AP), a processing server (PS), etc. Specifically, a BS of a universal terrestrial radio access (UTRAN) is referred to as an NB, a BS of an evolved UTRAN (E-UTRAN) is referred to as an eNB, and a BS of a new radio access technology network is referred to as a gNB. In the following, for the convenience of description, NB, eNB or gNB will be referred to as a BS regardless of the type or version of the communication technology.

[0062] In the present disclosure, a node refers to a fixed point that can send / receive a radio signal to / from a UE by communicating with the UE. Regardless of its name, various types of BSs can be used as nodes. For example, a BS, NB, eNB, picocell eNB (PeNB), home eNB (HeNB), repeater, transponder, etc. can be a node. In addition, a node may not be a BS. For example, a radio remote head (RRH) or a radio remote unit (RRU) can be a node. Typically, RRH and RRU have a power level lower than that of the BS. Since the RRH or RRU (hereinafter, RRH / RRU) is usually connected to the BS via a dedicated line such as an optical cable, the collaborative communication according to the RRH / RRU and the BS can be smoothly performed compared to the collaborative communication according to the BS connected via a wireless link. At least one antenna is installed per node. The antenna may refer to a physical antenna port or to a virtual antenna or an antenna group. A node may also be referred to as a point.

[0063] In the present disclosure, a cell refers to a specific geographical area where one or more nodes provide communication services. Therefore, in the present disclosure, communication with a specific cell may mean communication with a BS or node that provides communication services to a specific cell. The DL / UL signal of a specific cell refers to the DL / UL signal from / to the BS or node that provides communication services to the specific cell. A cell that provides UL / DL communication services to a UE is particularly referred to as a service cell. In addition, the channel state / quality of a specific cell refers to the channel state / quality of a channel or communication link generated between a BS or node that provides communication services to a specific cell and the UE. In a 3GPP-based communication system, a UE can use a CRS sent on a cell-specific reference signal (CRS) resource and / or a CSI-RS sent on a channel state information reference signal (CSI-RS) resource (allocated to a specific node by an antenna port of a specific node) to measure the DL channel state from a specific node.

[0064] The 3GPP-based communication system uses the concept of a cell in order to manage radio resources, and distinguishes a cell related to radio resources from a cell of a geographical area.

[0065] A "cell" of a geographic area may be understood as a coverage area in which a node can use a carrier to provide services, and a "cell" of radio resources is associated with a bandwidth (BW) which is a frequency range configured by a carrier. Since the DL coverage (the range in which a node can send a valid signal) and the UL coverage (the range in which a node can receive a valid signal from a UE) depend on the carrier that carries the signal, the coverage of a node may also be associated with the coverage of a "cell" of radio resources used by the node. Therefore, the term "cell" may be used to indicate the service coverage of a node at times, to indicate a radio resource at other times, or to indicate a range that a signal using a radio resource can reach with effective strength at other times.

[0066] In the 3GPP communication standard, the concept of a cell is used to manage radio resources. A "cell" associated with a radio resource is defined by a combination of DL resources and UL resources (i.e., a combination of DL component carriers (CCs) and UL CCs). A cell may be configured only by DL resources, or by a combination of DL resources and UL resources. If carrier aggregation is supported, the link between the carrier frequency of a DL resource (or DL ​​CC) and the carrier frequency of a UL resource (or UL CC) may be indicated by system information. For example, the combination of DL resources and UL resources may be indicated by a system information block type 2 (SIB2) link. In this case, the carrier frequency may be equal to or different from the center frequency of each cell or CC. When carrier aggregation (CA) is configured, the UE has only one radio resource control (RRC) connection with the network. During RRC connection establishment / reestablishment / handover, one serving cell provides non-access layer (NAS) mobility information. During RRC connection reestablishment / handover, one serving cell provides security input. The cell is called a primary cell (Pcell). Pcell refers to a cell operating on the primary frequency where the UE performs an initial connection establishment process or initiates a connection reestablishment process. According to the UE capabilities, the secondary cell (Scell) can be configured to form a set of serving cells together with the Pcell. The Scell ​​can be configured after the RRC connection establishment is completed and is used to provide additional radio resources in addition to the resources of the specific cell (SpCell). The carrier corresponding to the Pcell on the DL is called the downlink primary CC (DL PCC), and the carrier corresponding to the Pcell on the UL is called the uplink primary CC (UL PCC). The carrier corresponding to the Scell ​​on the DL is called the downlink secondary CC (DL SCC), and the carrier corresponding to the Scell ​​on the UL is called the uplink secondary CC (UL SCC).

[0067] In dual connectivity (DC) operation, the term special cell (SpCell) refers to a Pcell of a primary cell group (MCG) or a primary secondary cell (Pcell) of a secondary cell group (SCG). SpCell supports PUCCH transmission and contention-based random access and is always enabled. MCG is a group of service cells associated with a master node (e.g., BS) and includes SpCell (Pcell) and optionally one or more Scells. For a UE configured with DC, SCG is a subset of the service cells associated with the secondary node and includes PSCell and 0 or more Scells. PSCell is the primary Scell ​​of the SCG. For a UE in RRC_CONNECTED state that is not configured with CA or DC, there is only one service cell that includes only Pcell. For a UE in RRC_CONNECTED state that is configured with CA or DC, the term service cell refers to a set of cells including SpCell and all Scells. In DC, two medium access control (MAC) entities are configured for the UE, i.e., one MAC entity for MCG and one MAC entity for SCG.

[0068] For a UE configured with CA but not configured with DC, a Pcell PUCCH group (also referred to as a primary PUCCH group) including a Pcell and 0 or more Scells and a Scell ​​PUCCH group (also referred to as a secondary PUCCH group) including only Scells may be configured. For an Scell, a Scell ​​(hereinafter, PUCCH Scell) that transmits a PUCCH associated with a corresponding cell may be configured. The Scell ​​indicating that the PUCCH Scell ​​belongs to the Scell ​​PUCCH group (i.e., the secondary PUCCH group) and performs PUCCH transmission of related uplink control information (UCI) on the PUCCH Scell. If the PUCCH Scell ​​is not indicated for the Scell ​​or the cell indicating that the PUCCH transmission for the Scell ​​is the Pcell, the Scell ​​belongs to the Pcell PUCCH group (i.e., the primary PUCCH group) and performs PUCCH transmission of related UCI on the Pcell. In the following, if the UE is configured with an SCG and some implementations of the present disclosure related to PUCCH are applied to the SCG, the primary cell may refer to the PSCell of the SCG. If the UE is configured with a PUCCH Scell ​​and some implementations of the present disclosure related to PUCCH are applied to a secondary PUCCH group, the primary cell may refer to a PUCCH Scell ​​of the secondary PUCCH group.

[0069] In a wireless communication system, a UE receives information from a BS on DL, and a UE transmits information to a BS on UL. The information transmitted and / or received by the BS and the UE includes data and various control information, and there are various physical channels according to the type / purpose of the information transmitted and / or received by the UE and the BS.

[0070] The communication standards based on 3GPP define DL physical channels corresponding to resource elements carrying information from high layers and DL physical signals corresponding to resource elements used by the physical layer but not carrying information from high layers. For example, physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), physical multicast channel (PMCH), physical control format indicator channel (PCFICH), physical downlink control channel (PDCCH), etc. are defined as DL physical channels, and reference signals (RS) and synchronization signals are defined as DL physical signals. RS (also called pilot) represents a signal with a predefined special waveform known to both BS and UE. For example, demodulation reference signal (DMRS), channel state information RS (CSI-RS), positioning reference signal (PRS), etc. are defined as DL RS. The communication standards based on 3GPP define UL physical channels corresponding to resource elements carrying information from high layers and UL physical signals corresponding to resource elements used by the physical layer but not carrying information from high layers. For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are defined as UL physical channels, and a DMRS for UL control / data signals, a sounding reference signal (SRS) for UL channel measurement, etc. are defined.

[0071] In the present disclosure, PDCCH refers to a set of time-frequency resources (e.g., resource elements (REs)) carrying downlink control information (DCI), and PDSCH refers to a set of time-frequency resources carrying DL data. PUCCH, PUSCH, and PRACH refer to a set of time-frequency resources carrying UCI, a set of time-frequency resources carrying UL data, and a set of time-frequency resources carrying random access signals, respectively. In the following description, "UE sends / receives PUCCH / PUSCH / PRACH" is used as the same meaning as the UE sends / receives UCI / UL data / random access signals on PUCCH / PUSCH / PRACH or through PUSCH / PUCCH / PRACH, respectively. In addition, "BS sends / receives PBCH / PDCCH / PDSCH" is used as the same meaning as the BS sends broadcast information / DCI / DL data on PBCH / PDCCH / PDSCH or through PBCH / PDCCH / PDSCH, respectively.

[0072] In the present specification, radio resources (eg, time-frequency resources) scheduled or configured by a BS for a UE to transmit or receive a PUCCH / PUSCH / PDSCH may be referred to as PUCCH / PUSCH / PDSCH resources.

[0073] Since the communication device receives a synchronization signal (SS), DMRS, CSI-RS, PRS, PBCH, PDCCH, PDSCH, PUSCH and / or PUCCH in the form of a radio signal on a cell, the communication device may not select and receive a radio signal including only a specific physical channel or a specific physical signal through a radio frequency (RF) receiver, or may not select and receive a radio signal without a specific physical channel or a specific physical signal through an RF receiver. In actual operation, the communication device receives a radio signal on a cell via an RF receiver, converts the radio signal as an RF band signal into a baseband signal, and then uses one or more processors to decode the physical signal and / or physical channel in the baseband signal. Therefore, in some implementations of the present disclosure, not receiving a physical signal and / or a physical channel may mean that the communication device does not attempt to recover the physical signal and / or the physical channel from the radio signal, for example, does not attempt to decode the physical signal and / or the physical channel, rather than the non-communication device actually receiving a radio signal including the corresponding physical signal and / or the physical channel.

[0074] As more and more communication devices require greater communication capacity, eMBB communication relative to traditional radio access technology (RAT) is needed. In addition, large-scale MTC, which provides various services anytime and anywhere by connecting multiple devices and objects to each other, is a major issue to be considered in the next generation of communications. In addition, the design of communication systems that take into account services / UEs that are sensitive to reliability and delay is also being discussed. Considering eMBB communication, large-scale MTC, ultra-reliable low-latency communication (URLLC), etc., the introduction of the next generation RAT is being discussed. Currently, in 3GPP, research on the next generation mobile communication system after EPC is underway. In this disclosure, for convenience, the corresponding technology is referred to as a new RAT (NR) or a fifth generation (5G) RAT, and a system using NR or supporting NR is referred to as an NR system.

[0075] Figure 1 An example of a communication system 1 to which an implementation of the present disclosure is applied is shown. Figure 1, the communication system 1 applied to the present disclosure includes a wireless device, a BS, and a network. Here, the wireless device refers to a device that performs communication using a RAT (e.g., 5G NR or LTE (e.g., E-UTRA)), and may be referred to as a communication / radio / 5G device. The wireless device may include (but is not limited to) a robot 100a, a vehicle 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing vehicle-to-vehicle communication. Here, a vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television, a smart phone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters. For example, BSs and networks may also be implemented as wireless devices, and a specific wireless device may operate as a BS / network node relative to another wireless device.

[0076] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. The AI ​​technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without passing through the BS / network. For example, vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0077] Wireless communication / connection 150a and 150b may be established between wireless devices 100a to 100f and BS200, and between wireless devices 100a to 100f. Here, wireless communication / connection such as UL / DL communication 150a and sidelink communication 150b (or device-to-device (D2D) communication) may be established through various RATs (e.g., 5G NR). The wireless device and the BS / wireless device may send / receive radio signals to / from each other through wireless communication / connection 150a and 150b. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and at least a portion of a resource allocation process may be performed based on various proposals of the present disclosure.

[0078] Figure 2 is a block diagram showing an example of a communication device capable of executing the method according to the present disclosure. Figure 2 , the first wireless device 100 and the second wireless device 200 may transmit and / or receive radio signals through various RATs (e.g., LTE and NR). Here, {the first wireless device 100 and the second wireless device 200} may correspond to Figure 1 {wireless device 100x and BS 200} and / or {wireless device 100x and wireless device 100x}.

[0079] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106, and may be configured to implement the functions, processes and / or methods described / proposed below. For example, the processor 102 may process the information in the memory 104 to generate first information / signal, and then transmit a radio signal including the first information / signal through the transceiver 106. The processor 102 may receive a radio signal including second information / signal through the transceiver 106, and then store information obtained by processing the second information / signal in the memory 104. The memory 104 may be connected to the processor 102, and may store various information related to the operation of the processor 102. For example, the memory 104 may execute part or all of the processes controlled by the processor 102 or store software codes including commands for executing the processes and / or methods described / proposed below. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0080] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the functions, processes and / or methods described / proposed below. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then transmit a radio signal including the third information / signals through the transceiver 206. The processor 202 may receive a radio signal including fourth information / signals through the transceiver 206, and then store information obtained by processing the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202, and may store various information related to the operation of the processor 202. For example, the memory 204 may execute part or all of the processes controlled by the processor 202 or store software codes including commands for executing the processes and / or methods described / proposed below. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0081] The wireless communication technology implemented in the wireless devices 100 and 200 of the present disclosure may include narrowband Internet of Things for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of low-power wide area network (LPWAN) technology and is implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2. However, NB-IoT technology is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices XXX and YYY of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and is referred to as various names including enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented in accordance with at least one of the following various standards: 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine type communication and / or 7) LTE M, etc., but LTE-M technology is not limited to the above names. Additionally or alternatively, in consideration of low power communication, the wireless communication technology implemented in the wireless devices XXX and YYY of the present disclosure may include at least one of ZigBee, Bluetooth, and LPWAN, but the wireless communication technology is not limited to the above names. For example, ZigBee technology may be based on various standards such as IEEE 802.15.4 to create a personal area network (PAN) related to small / low power digital communication, and ZigBee technology may be referred to as various names.

[0082] Hereinafter, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by (but not limited to) one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a service data adaptation protocol (SDAP) layer). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure. One or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, an SDU, a message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure, and provide the generated signal to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106 and 206 and obtain the PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure.

[0083] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The functions, processes, proposals, and / or methods disclosed in the present disclosure may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to perform the functions, processes, proposals, and / or methods disclosed in the present disclosure may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 to be driven by one or more processors 102 and 202. The functions, processes, proposals, and / or methods disclosed in the present disclosure may be implemented using firmware or software in the form of code, commands, and / or command sets.

[0084] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, commands and / or instructions. One or more memories 104 and 204 may be configured by read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard disk drive, register, cache memory, computer-readable storage medium and / or a combination thereof. One or more memories 104 and 204 may be located inside and / or outside of one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 by various technologies such as wired or wireless connections.

[0085] One or more transceivers 106 and 206 may send the user data, control information and / or radio signal / channel mentioned in the method and / or operation flow chart of the present disclosure to one or more other devices. One or more transceivers 106 and 206 may receive the user data, control information and / or radio signal / channel mentioned in the function, process, proposal, method and / or operation flow chart disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202 and send and receive radio signals. For example, one or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may send user data, control information or radio signal to one or more other devices. One or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may receive user data, control information or radio signal from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208. One or more transceivers 106 and 206 may be configured to send and receive user data, control information and / or radio signals / channels mentioned in the functional, process, proposal, method and / or operation flow chart disclosed in the present disclosure through one or more antennas 108 and 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert received radio signals / channels, etc. from RF band signals to baseband signals so as to process received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more of the transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0086] Figure 3 Another example of a wireless device capable of executing implementations of the present disclosure is shown. Figure 3 , the wireless devices 100 and 200 may correspond to Figure 2 The wireless devices 100 and 200 of the present invention may be configured by various elements, components, units / parts and / or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130 and an additional component 140. The communication unit may include a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 may include Figure 2One or more processors 102 and 202 and / or one or more memories 104 and 204. For example, the transceiver 114 may include Figure 2 The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140, and controls the overall operation of the wireless device. For example, the control unit 120 may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit 130. The control unit 120 may send information stored in the memory unit 130 to the outside (e.g., other communication devices) via the communication unit 110 through a wireless / wired interface, or store information received from the outside (e.g., other communication devices) via the communication unit 110 in the memory unit 130 through a wireless / wired interface.

[0087] The additional components 140 may be configured differently depending on the type of wireless device. For example, the additional components 140 may include at least one of a power supply unit / battery, an input / output (I / O) unit, a drive unit, and a computing unit. The wireless device may be configured in the form of, but not limited to, a robot ( Figure 1 100a), vehicles ( Figure 1 100b-1 and 100b-2), XR devices ( Figure 1 100c), handheld device ( Figure 1 100d), household appliances ( Figure 1 100e), IoT devices ( Figure 1 100f), digital broadcast UE, holographic device, public safety device, MTC device, medical device, fintech device (or financial device), security device, climate / environmental device, AI server / device ( Figure 1 400), BS( Figure 1 200), network nodes, etc. The wireless device can be used in a mobile or fixed location depending on the usage / service.

[0088] exist Figure 3In the wireless devices 100 and 200, various elements, components, units / parts and / or modules in the wireless devices 100 and 200 may all be connected to each other through a wired interface, or at least a part thereof may be wirelessly connected through the communication unit 110. For example, in each of the wireless devices 100 and 200, the control unit 120 and the communication unit 110 may be wired, and the control unit 120 and the first unit (e.g., 130 and 140) may be wirelessly connected through the communication unit 110. The various elements, components, units / parts and / or modules within the wireless devices 100 and 200 may also include one or more elements. For example, the control unit 120 may be configured by a collection of one or more processors. As an example, the control unit 120 may be configured by a collection of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing unit and a memory control processor. As another example, the memory 130 may be configured by a random access memory (RAM), a dynamic RAM (DRAM), a read-only memory (ROM)), a flash memory, a volatile memory, a non-volatile memory and / or a combination thereof.

[0089] In the present disclosure, at least one memory (e.g., 104 or 204) may store instructions or programs, and these instructions or programs, when executed, may cause at least one processor operatively connected to the at least one memory to perform operations according to some embodiments or implementations of the present disclosure.

[0090] In the present disclosure, a computer-readable (non-temporary) storage medium may store at least one instruction or program, and when the at least one instruction or program is executed by at least one processor, the at least one processor may cause the at least one processor to perform operations according to some embodiments or implementations of the present disclosure.

[0091] In the present disclosure, a processing device or apparatus may include at least one processor and at least one computer memory operatively connected to the at least one processor. The at least one computer memory may store instructions or programs, and these instructions or programs, when executed, may cause at least one processor operatively connected to the at least one memory to perform operations according to some embodiments or implementations of the present disclosure.

[0092] In the present disclosure, a computer program may include program code stored on at least one computer-readable (non-volatile) storage medium, and when executed, it is configured to perform operations according to some implementations of the present disclosure or cause at least one processor to perform operations according to some implementations of the present disclosure. The computer program may be provided in the form of a computer program product. The computer program product may include at least one computer-readable (non-volatile) storage medium.

[0093] The communication device of the present disclosure includes: at least one processor; and at least one computer memory, which is operatively connected to the at least one processor and configured to store instructions, which when executed cause the at least one processor to perform operations according to examples of the present disclosure described later.

[0094] Figure 4 An example of a frame structure used in a 3GPP-based wireless communication system is shown.

[0095] Figure 4 The frame structure is only exemplary, and the number of subframes, the number of time slots, and the number of symbols in the frame may be changed differently. In the NR system, different OFDM parameter sets (e.g., subcarrier spacing (SCS)) may be configured for multiple cells aggregated for one UE. Therefore, the (absolute time) duration of time resources including the same number of symbols (e.g., subframes, time slots, or transmission time intervals (TTIs)) may be configured differently for the aggregated cells. Here, the symbol may include an OFDM symbol (or a cyclic prefix-OFDM (CP-OFDM) symbol) and an SC-FDMA symbol (or a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol). In the present disclosure, symbols, OFDM-based symbols, OFDM symbols, CP-OFDM symbols, and DFT-s-OFDM symbols may be used interchangeably.

[0096] Reference Figure 4 In the NR system, UL transmission and DL transmission are organized into frames. Each frame has T f =(△f max *N f / 100)*T c = 10 ms duration and is divided into two half frames of 5 ms each. The basic time unit of NR is T c =1 / (△f max *N f ), where △f max =480*10 3 Hz and N f =4096. For reference, the basic time unit of LTE is T s =1 / (△f ref *N f,ref ), where △f ref =15*10 3 Hz and N f,ref =2048. c and T f With constant κ = T c / T f =64. Each half frame includes 5 subframes, and the duration of a single subframe is T sfThe subframe is further divided into slots, and the number of slots in a subframe depends on the subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on the cyclic prefix. In normal CP, each slot includes 14 OFDM symbols, and in extended CP, each slot includes 12 OFDM symbols. The parameter set depends on the exponentially scalable subcarrier spacing △f=2 u *15kHz. The following table shows the number of OFDM symbols per time slot (N slot symb ), the number of time slots per frame (N frame,u slot ) and the number of time slots per subframe (N subframe,u slot ).

[0097] [Table 1]

[0098]

[0099]

[0100] The following table shows the subcarrier spacing △f = 2 u *15kHz, number of OFDM symbols per slot, number of slots per frame and number of slots per subframe.

[0101] [Table 2]

[0102] u <![CDATA[N slot symb ]]> <![CDATA[N frame,u slot ]]> <![CDATA[N subframe,u slot ]]> 2 12 40 4

[0103] For subcarrier spacing configuration u, the time slots may be indexed in ascending order within a subframe as follows: n u s ∈{0,...,n subframe ,u slot -1}, and are indexed in ascending order within the frame as follows: n u s,f ∈{0,...,n frame,u slot -1}.

[0104] Figure 5 A resource grid of a time slot is shown. A time slot includes multiple (e.g., 14 or 12) symbols in the time domain. For each parameter set (e.g., subcarrier spacing) and carrier, a common resource block (CRB) N is indicated by higher layer signaling (e.g., RRC signaling). start,u grid Begins to define N size,u grid,x *N RB sc subcarriers and N subframe,u symbOFDM symbol resource grid, where N size,u grid,x is the number of resource blocks (RBs) in the resource grid, and the subscript x is DL for the downlink and UL for the uplink. N RB sc is the number of subcarriers per RB. In 3GPP-based wireless communication systems, N RB sc Typically 12. For a given antenna port p, subcarrier spacing configuration u, and transmission link (DL or UL), there is one resource grid. The carrier bandwidth N for subcarrier spacing configuration u is given to the UE through higher-layer parameters (e.g., RRC parameters) size,u grid . Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex symbol can be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l representing the symbol position relative to a reference point in the time domain. In the NR system, an RB is defined by 12 consecutive subcarriers in the frequency domain. In the NR system, RBs are classified into CRBs and physical resource blocks (PRBs). For subcarrier spacing configuration u, CRBs are numbered from 0 upwards in the frequency domain. The center of subcarrier 0 of CRB 0 of subcarrier spacing configuration u is equal to "point A" used as a common reference point for the RB grid. PRBs for subcarrier spacing configuration u are defined within a bandwidth part (BWP) and are numbered from 0 to N. size,u BWP,i -1 numbering, where i is the number of BWPs. PRB n in BWPi PRB With CRB u CRB The relationship between n u PRB =n u CRB +N size,u BWP,i Given, where N size BWP,i is the CRB at which the BWP starts relative to CRB 0. A BWP includes multiple consecutive RBs in the frequency domain. For example, a BWP may be a CRB with a given parameter set u in BWP i on a given carrier. i A subset of contiguous CRBs defined by the UE. A carrier may include up to N (e.g., 5) BWPs. A UE may be configured with one or more BWPs on a given component carrier. Data communication is performed through enabled BWPs, and only a predetermined number of BWPs (e.g., one BWP) among the BWPs configured for the UE may be active on the component carrier.

[0105] For each serving cell in the set of DL BWPs or UL BWPs, the network may configure at least an initial DL BWP and one (if the serving cell is configured with uplink) or two (if supplementary uplink is used) initial UL BWPs. The network may configure additional UL and DL BWPs. For each DL BWP or UL BWP, the following parameters may be provided to the UE for the serving cell: i) SCS; ii) CP; iii) start BWP＝ 275 indicates the offset RB set and length L RB CRB N provided as the RRC parameter locationAndBandwidth of the Resource Indicator Value (RIV) start BWP =O carrier +RB start and the number of adjacent RBs N size BWP =L RB , and the value O provided by the RRC parameter offsetToCarrier for SCS carrier ; an index into a set of DL BWP or UL BWP; a set of BWP common parameters; and a set of BWP dedicated parameters.

[0106] Virtual Resource Blocks (VRBs) can be defined within a BWP and are numbered from 0 to N. size,u BWP,i -1 index, where i represents the BWP number. VRBs may be mapped to PRBs according to an interleaved mapping or a non-interleaved mapping. In some implementations, for non-interleaved VRB to PRB mapping, VRB n may be mapped to PRB n.

[0107] NR frequency bands are defined as two types of frequency ranges, namely, FR1 and FR2. FR2 is also known as millimeter wave (mmW). The following table shows the frequency ranges in which NR can operate.

[0108] [Table 3]

[0109] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0110] Figure 6 is a diagram showing physical channels in a 3GPP-based communication system as an exemplary wireless communication system and a signal transmission / reception process using the physical channels.

[0111] When the UE is powered on or when the UE has been disconnected from the wireless communication system, the UE searches for a cell to reside in and performs an initial cell search, involving synchronization with a BS in the cell (S11). For the initial cell search, the UE receives a synchronization signal block (SSB) (also called an SSB / PBCH block) from the BS. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The UE establishes synchronization with the BS based on the PSS / SSS and obtains information such as a cell identification (ID). The UE can obtain broadcast information in the cell based on the PBCH. The UE can receive a DL reference signal (RS) during the initial cell search to monitor the DL channel status.

[0112] After the initial cell search, the UE may camp on the cell. Subsequently, the UE may monitor the PDCCH in the cell and acquire more specific system information by receiving the PDSCH based on the DCI carried on the PDCCH (S12).

[0113] Subsequently, in order to complete the connection with the BS, the UE may perform a random access procedure (S13 to S16). In the random access procedure, for example, the UE may send a preamble on the PRACH (S13) and receive a PDCCH and a random access response (RAR) to the preamble on the PDSCH corresponding to the PDCCH (S14). When the UE fails to receive the RAR directed to the UE, the UE may attempt to retransmit the preamble. In the case of contention-based random access, the UE may send a PUSCH based on the UL resource assignment included in the RAR (S15), and perform a contention resolution procedure including reception of the PDCCH and the PDSCH corresponding to the PDCCH (S16).

[0114] After the above process, the UE may receive PDCCH / PDSCH from the BS (S17) and send PUSCH / PUCCH to the BS (S18) during general UL / DL signal transmission. The control information sent by the UE to the BS is generally referred to as uplink control information (UCI). UCI includes hybrid automatic repeat request acknowledgment / negative acknowledgment (HARQ ACK / NACK), scheduling request (SR) and channel state information (CSI). CSI includes channel quality indicator (CQI), precoding matrix indicator (PMI) and / or rank indication (RI). Typically, UCI is sent on PUCCH. However, when control information and data should be sent simultaneously, control information may be sent on PUSCH. In addition, upon receiving a request / command from the network, the UE may send UCI on PUSCH aperiodically.

[0115] Figure 7The system information (SI) acquisition process is shown. The UE can acquire access stratum / non-access stratum (AS / NAS) information from the SI acquisition process. The SI acquisition process can be applied to UEs in the following states: RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED. RRC_CONNECTED refers to a state in which the UE has established an RRC connection with the network. RRC_IDLE refers to a state in which the UE is not registered in a specific cell and has not received an AS context and other information from the network. RRC_INACTIVE refers to a state in which the UE remains in a state called CM-CONNECTED, in which the UE has a signaling connection with the core network for connection management (CM) and is able to move within an area defined by a radio access network (RAN) (e.g., BS) without notifying the RAN. CM_CONNECTED refers to a state in which the UE has a NAS signaling connection with the core network. CM_IDLE refers to a state in which the UE has no NAS signaling connection.

[0116] In a 3GPP-based system, system information (SI) may be classified into a master information block (MIB) and multiple system information blocks (SIBs). The MIB and multiple SIBs are divided into minimum system information (SI) and other SI, where the minimum SI consists of the MIB and system information block 1 (SIB1), and includes basic information required for initial access and information for acquiring any other SI. SIB1 may be referred to as remaining minimum system information (RMSI). Details are provided below.

[0117] -MIB is always sent on BCH with a periodicity of 80ms and is repeated within 80ms. MIB includes information / parameters related to SIB1 reception and is sent through PBCH in SSB. During initial cell selection, the UE assumes that the half frame including the SSB is repeated with a periodicity of 20ms. The UE can determine whether there is a control resource set (CORESET) for the Type0-PDCCH common search space based on the MIB. The Type0-PDCCH common search space is a PDCCH search space and is used to send a PDCCH that schedules SI messages. When a Type0-PDCCH common search space exists, the UE can determine (i) multiple consecutive RBs and one or more consecutive symbols included in the CORESET and (ii) the PDCCH timing (i.e., the time domain position for PDCCH reception) based on the information in the MIB (e.g., pdcch-ConfigSIB1). When there is no Type0-PDCCH common search space, pdcch-ConfigSIB1 provides information about the frequency position where SSB / SIB1 exists and information about the frequency range where SSB / SIB1 does not exist.

[0118] -SIB1 is sent on the downlink shared channel (DL-SCH) with a periodicity of 160ms and a variable transmission repetition periodicity within 160ms. The default transmission repetition periodicity of SIB1 is 20ms, but the actual transmission repetition periodicity depends on the network implementation. SIB1 includes information about the availability and scheduling (e.g., transmission periodicity and SI window size) of the remaining SIBs (hereinafter referred to as SIBx, where x is an integer greater than or equal to 2). For example, SIB1 may indicate whether SIBx is broadcast periodically or provided on demand at the request of the UE. When SIBx is provided on demand, SIB1 may include the information required by the UE to perform an SI request. SIB1 is a cell-specific SIB. The PDCCH that schedules SIB1 is sent in the Type0-PDCCH common search space, and SIB1 is sent via the PDSCH indicated by the PDCCH.

[0119] -SIBx is included in the SI message and transmitted through the PDSCH. Each SI message is transmitted within a time window (ie, SI window) that occurs periodically.

[0120] Figure 8 The random access process applicable to the implementation of the present disclosure is shown. Specifically, Figure 8 (a) shows a 4-step random access process, Figure 8 (b) shows a 2-step random access process.

[0121] The random access procedure can be used for various purposes, including initial access, UL synchronization adjustment, resource allocation, switching, radio link reconfiguration after radio link failure, and positioning. The random access procedure is classified into a contention-based procedure and a dedicated (i.e., non-contention-based) procedure. The contention-based random access procedure generally involves initial access, while the dedicated random access procedure is used for UL synchronization reconfiguration in the case of switching, DL data arriving at the network, and positioning. In the contention-based random access procedure, the UE randomly selects a random access (RA) preamble. Therefore, multiple UEs may send the same RA preamble at the same time, so a subsequent contention resolution procedure is required. In the dedicated random access procedure, the UE uses the RA preamble uniquely allocated by the BS to the UE. Therefore, the UE can perform a random access procedure without conflicting with other UEs.

[0122] Reference Figure 8 (a) of the present invention, the contention-based random access procedure includes the following four steps. The messages sent in steps 1 to 4 may be referred to as message 1 (Msg1) to message 4 (Msg4), respectively.

[0123] - Step 1: UE sends RA preamble on PRACH.

[0124] - Step 2: The UE receives the RAR from the BS on the PDSCH.

[0125] -Step 3: The UE sends UL data to the BS on the PUSCH. The UL data includes a layer 2 (L2) / layer 3 (L3) message.

[0126] - Step 4: The UE receives a contention resolution message from the BS on the PDSCH.

[0127] The UE may receive random access information from the BS in the system information. For example, information about the RACH timing associated with the SSB on the cell may be provided in the system information. The UE may select an SSB whose reference signal received power (RSRP) measured based on the SSB exceeds a threshold among the SSBs received on the cell. The UE may then send an RA preamble on the PRACH associated with the selected SSB. For example, when the UE requires random access, the UE sends Msg1 (e.g., a preamble) to the BS on the PRACH. The BS may identify each RA preamble by the time / frequency resource (RA timing (RO)) carrying the RA preamble and the preamble index (PI). Upon receiving the RA preamble from the UE, the BS sends a RAR message to the UE on the PDSCH. In order to receive the RAR message, the UE monitors the L1 / L2 control channel (PDCCH) with a cyclic redundancy check (CRC) masked with a random access-RNTI (RA-RNTI) within a preconfigured time window (e.g., ra-ResponseWindow), including scheduling information for the RAR message. When scheduling information is received on the PDCCH masked with RA-RNTI, the UE may receive a RAR message on the PDSCH indicated by the scheduling information. The UE then checks whether there is a RAR pointing to the UE in the RAR message. Whether there is a RAR pointing to the UE can be determined by checking whether there is a random access preamble ID (RAPID) of the preamble sent by the UE. The index of the preamble sent by the UE may be the same as the RAPID. The RAR includes the index of the corresponding RA preamble, the timing offset information of UL synchronization (e.g., timing advance command (TAC)), the UL scheduling information (e.g., UL grant) transmitted by Msg3, and the UE temporary identification information (e.g., temporary-C-RNTI (TC-RNTI)). Upon receiving the RAR, the UE sends Msg3 on the PUSCH according to the UL scheduling information and timing offset value in the RAR. Msg3 may include the ID (or global ID) of the UE. In addition, Msg3 may include RRC connection request related information (e.g., RRCSetupRequest message) for initial access to the network. After receiving Msg3, the BS sends a contention resolution message (i.e., Msg4) to the UE. When the UE receives the contention resolution message and the contention resolution is successful, the TC-RNTI is changed to the C-RNTI. Msg4 may include the ID of the UE / RRC connection related information (e.g., RRCSetup message). When the information sent in Msg3 does not match the information received in Msg4 or when the UE does not receive Msg4 within a predetermined time, the UE may determine that the contention resolution has failed and retransmit Msg3.

[0128] The dedicated random access procedure includes the following three steps. The messages sent in step 0 to step 2 may be referred to as Msg0 to Msg2, respectively. The BS may trigger the dedicated random access procedure through a PDCCH serving the purpose of commanding RA preamble transmission (hereinafter, referred to as a PDCCH command).

[0129] - Step 0: The BS allocates a RA preamble to the UE through dedicated signaling.

[0130] - Step 1: UE sends RA preamble on PRACH.

[0131] - Step 2: The UE receives the RAR from the BS on the PDSCH.

[0132] Step 1 and step 2 of the dedicated random access procedure may be the same as step 1 and step 2 of the contention-based random access procedure.

[0133] NR systems may require lower latency than legacy systems. In particular, for delay-sensitive services such as URLLC, a 4-step random access procedure may not be preferred. Various scenarios in NR systems may require a low-latency random access procedure. When the implementation of the present disclosure is implemented together with a random access procedure, the implementation of the present disclosure may be implemented together with the following 2-step random access procedure to reduce the delay involved in the random access procedure.

[0134] Reference Figure 8 (b), the 2-step random access procedure may be performed in two steps: MsgA transmission from the UE to the BS and MsgB transmission from the BS to the UE. MsgA transmission may include transmission of an RA preamble on the PRACH and transmission of an UL payload on the PUSCH. In MsgA transmission, the PRACH and the PUSCH may be transmitted in time division multiplexing (TDM). Alternatively, in MsgA transmission, the PRACH and the PUSCH may be transmitted in frequency division multiplexing (FDM).

[0135] Upon receiving MsgA, the BS may send MsgB to the UE. MsgB may include the RAR for the UE.

[0136] An RRC connection request related message (e.g., an RRCSetupRequest message) requesting establishment of a connection between the RRC layer of the BS and the RRC layer of the UE may be included in the payload of MsgA. In this case, MsgB may be used to send RRC connection related information (e.g., an RRCSetup message). In contrast, an RRC connection request related message (e.g., an RRCSetupRequest message) may be sent on the PUSCH based on the UL grant in MsgB. In this case, RRC connection related information (e.g., an RRCSetup message) related to the RRC connection request may be sent on the PDSCH associated with the PUSCH transmission after the PUSCH transmission based on MsgB.

[0137] Hereinafter, physical channels available in a 3GPP-based wireless communication system will be described in detail.

[0138] PDCCH carries DCI. For example, PDCCH (i.e., DCI) carries information about the transmission format and resource allocation of the downlink shared channel (DL-SCH), information about the resource allocation of the uplink shared channel (UL-SCH), paging information about the paging channel (PCH), system information about DL-SCH, resource allocation information of control messages of a layer higher than the physical layer (hereinafter, high layer) in the protocol stack of UE / BS (e.g., random access response (RAR) sent on PDSCH), transmission power control commands, information about the activation / deactivation of configuration scheduling (CS), etc. DCI including resource allocation information about DL-SCH is called PDSCH scheduling DCI, and DCI including resource allocation information about UL-SCH is called PUSCH scheduling DCI. DCI includes a cyclic redundancy check (CRC). The CRC is masked / scrambled with various identifiers (e.g., radio network temporary identifier (RNTI)) according to the owner and purpose of the PDCCH. For example, if the PDCCH is for a specific UE, the CRS is masked with a UE identifier (e.g., cell-RNTI (C-RNTI)). If the PDCCH is for a paging message, the CRC is masked with a paging RNTI (P-RNTI). If the PDCCH is for system information (e.g., system information block (SIB)), the CRC is masked with a system information RNTI (SI-RNTI). If the PDCCH is for a random access response, the CRC is masked with a random access-RNTI (RA-RNTI).

[0139] When the PDCCH on one serving cell schedules the PDSCH or PUSCH on another serving cell, it is called cross-carrier scheduling. Cross-carrier scheduling with a carrier indicator field (CIF) allows the PDCCH on the serving cell to schedule resources on another serving cell. When the PDSCH on the serving cell schedules the PDSCH or PUSCH on the serving cell, it is called self-carrier scheduling. When cross-carrier scheduling is used in a cell, the BS may provide information about the cell of the scheduling cell to the UE. For example, the BS may inform the UE whether the serving cell is scheduled by the PDCCH on another (scheduling) cell or by the serving cell. If the serving cell is scheduled by another (scheduling) cell, the BS may inform the UE which cell signals the DL assignment and UL grant of the serving cell. In the present disclosure, the cell carrying the PDCCH is referred to as the scheduling cell, and the cell whose transmission of the PUSCH or PDSCH is scheduled by the DCI included in the PDCCH (i.e., the cell carrying the PUSCH or PDSCH scheduled by the PDCCH) is referred to as the scheduled cell.

[0140] PDSCH is a physical layer UL channel for UL data transmission. PDSCH carries DL data (e.g., DL-SCH transport block) and is subjected to modulation such as quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), 64QAM, 256QAM, etc. Codewords are generated by encoding transport blocks (TBs). PDSCH can carry up to two codewords. Scrambling and modulation mapping of each codeword can be performed, and modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to a radio resource together with a DMRS and generated as an OFDM symbol signal. Then, the OFDM symbol signal is sent through the corresponding antenna port.

[0141] Fig. 9 An example of PDSCH TDRA caused by PDCCH and an example of PUSCH TDRA caused by PDCCH are shown.

[0142] The DCI carried by the PDCCH for scheduling PDSCH or PUSCH includes a TDRA field. The TDRA field provides a value m of row index m+1 for the allocation table of PDSCH or PUSCH. The predefined default PDSCH time domain allocation is applied as the allocation table of PDSCH, or the PDSCH TDRA table configured by the BS through the RRC signal pdsch-TimeDomainAllocationList is applied as the allocation table of PDSCH. The predefined default PUSCH time domain allocation is applied as the allocation table of PUSCH, or the PUSCH TDRA table configured by the BS through the RRC signal pusch-TimeDomainAllocationList is applied as the allocation table of PUSCH. The PDSCH TDRA table to be applied and / or the PUSCH TDRA table to be applied can be determined according to fixed / predefined rules (for example, refer to 3GPPTS 38.214).

[0143] In the PDSCH time domain resource configuration, each index row defines the DL assignment with the PDSCH slot offset K0, the start and length indicator SLIV (or the starting position (e.g., starting symbol index S) and allocation length (e.g., number of symbols L) of the PDSCH in the direct slot), and the PDSCH mapping type. In the PUSCH time domain resource configuration, each index row defines the UL grant with the PUSCH slot offset K2, the starting position (e.g., starting symbol index S) and allocation length (e.g., number of symbols L) of the PUSCH in the slot, and the PUSCH mapping type. K0 of PDSCH and K2 of PUSCH indicate the difference between the slot with PDCCH and the slot with PDSCH or PUSCH corresponding to the PDCCH. SLIV represents a joint indicator of the starting symbol S relative to the beginning of the slot with PDSCH or PUSCH and the number of consecutive symbols L counted from symbol S. There are two PDSCH / PUSCH mapping types: one is mapping type A and the other is mapping type B. In the case of PDSCH / PUSCH mapping type A, DMRS is mapped to the PDSCH / PUSCH resource relative to the beginning of the time slot. Depending on other DMRS parameters, one or two symbols of the PDSCH / PUSCH resource may be used as DMRS symbols. For example, in the case of PDSCH / PUSCH mapping type A, according to RRC signaling, the DMRS is located in the third symbol (symbol #2) or the fourth symbol (symbol #3) in the time slot. In the case of PDSCH / PUSCH mapping type B, DMRS is mapped relative to the first OFDM symbol of the PDSCH / PUSCH resource. Depending on other DMRS parameters, one or two symbols from the first symbol of the PDSCH / PUSCH resource may be used as DMRS symbols. For example, in the case of PDSCH / PUSCH mapping type B, DMRS is located at the first symbol allocated for PDSCH / PUSCH. In the present disclosure, the PDSCH / PUSCH mapping type may be referred to as a mapping type or a DMRS mapping type. For example, in the present specification, PUSCH mapping type A may be referred to as mapping type A or DMRS mapping type A, and PUSCH mapping type B may be referred to as mapping type B or DMRS mapping type B.

[0144] The scheduling DCI includes an FDRA field that provides assignment information about RBs for PDSCH or PUSCH. For example, the FDRA field provides information about a cell used for PDSCH or PUSCH transmission to a UE, information about a BWP used for PDSCH or PUSCH transmission, and / or information about RBs used for PDSCH or PUSCH transmission.

[0145] A CORESET may be defined and / or configured as a set of time-frequency resources in which a UE can monitor a PDCCH. A UE may be configured with one or more CORESETs. A CORESET has a duration of one to three OFDM symbols and includes a set of PRBs. The PRBs included in the CORESET and the CORESET duration may be provided to the UE via high-level (e.g., RRC) signaling. The UE may monitor a set of PDCCH candidates in the configured CORESET according to a corresponding search space set. In the present disclosure, monitoring means decoding (blind decoding) of each PDCCH candidate based on the monitored DCI format. The MIB on the PBCH provides the UE with parameters (e.g., CORESET#0 configuration) for monitoring the PDCCH that schedules the PDSCH carrying SIB1. The PBCH may indicate that there is no associated SIB1. In this case, the UE may be provided not only with a frequency range in which the UE is allowed to assume that there is no SSB associated with SSB1, but also with another frequency range in which the UE is allowed to discover SSBs associated with SIB1. As a CORESET for scheduling at least SIB1, CORESET#0 may be configured through MIB or dedicated RRC signaling.

[0146] The PDCCH candidate set monitored by the UE is defined according to the PDCCH search space set. The search space set can be a common search space (CSS) set or a UE-specific search space (USS) set. Each CORESET configuration is associated with one or more search space sets, and each search space set is associated with one CORESET configuration.

[0147] The UE monitors a set of PDCCH candidates in one or more CORESETs on an active DLBWP on each enabled serving cell configured with PDCCH monitoring according to a corresponding search space set, where monitoring means receiving each PDCCH candidate and decoding according to the monitored DCI format.

[0148] The following table shows the PDCCH search space.

[0149] [Table 4]

[0150]

[0151] The SS set may be configured via system information (e.g., MIB) or UE-specific high-layer (e.g., RRC) signaling. S (e.g., 10) SS sets or fewer SS sets may be configured in each DL BWP of a serving cell. For example, the following parameters / information may be provided for each SS set. Each SS set may be associated with one CORESET, and each CORESET configuration may be associated with one or more SS sets.

[0152] -searchSpaceId: indicates the ID of the SS set.

[0153] -controlResourceSetId: Indicates the CORESET associated with the SS set.

[0154] - monitoringSlotPeriodicityAndOffset: indicates the PDCCH monitoring periodicity (in time slots) and the PDCCH monitoring offset (in time slots).

[0155] -monitoringSymbolsWithinSlot: Indicates the first OFDMA symbol for PDCCH monitoring in the slot where PDCCH monitoring is configured. The first OFDMA symbol is indicated by a bitmap, and each bit corresponds to a corresponding one of the OFDMA symbols in the slot. The MSB of the bitmap corresponds to the first OFDM symbol in the slot. The OFDMA symbol corresponding to the bit with a value of 1 corresponds to the first symbol in the CORESET in the slot.

[0156] -nrofCandidates: indicates the number (eg, one of 0, 1, 2, 3, 4, 5, 6, and 8) of PDCCH candidates for each AL (where AL={1, 2, 4, 8, 16}).

[0157] -searchSpaceType: Indicates whether the SS type is CSS or USS.

[0158] -DCI format: indicates the DCI format of the PDCCH candidate.

[0159] The UE may monitor PDCCH candidates in one or more SS sets in a time slot according to the configuration of the CORESET / SS set. The timing (e.g., time / frequency resource) of monitoring PDCCH candidates is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities may be configured in a time slot.

[0160] Fig.10 The SSB and CORESET multiplexing patterns are shown. Specifically, Fig.10 (a) shows SSB and CORESET multiplexing pattern 1, Fig.10 (b) shows SSB and CORESET multiplexing pattern 2, Fig.10 (c) shows SSB and CORESET multiplexing pattern 3. The SSB and CORESET multiplexing patterns may be defined according to a frequency range (FR) to which a corresponding cell belongs or a subcarrier spacing of an SSB or a PDCCH.

[0161] like Fig.10As shown, SSB and CORESET can be multiplexed in the time domain, in the time domain and frequency domain, or in the frequency domain.

[0162] The PDCCH candidate set monitored by the UE is defined according to the PDCCH search space set. The search space set can be a common search space (CSS) set or a UE-specific search space (USS) set. Each CORESET configuration is associated with one or more search space sets, and each search space set is associated with one CORESET configuration.

[0163] The UE monitors a set of PDCCH candidates in one or more CORESETs on an active DLBWP on each enabled serving cell configured with PDCCH monitoring according to a corresponding search space set, where monitoring means receiving each PDCCH candidate and decoding according to the monitored DCI format.

[0164] Fig.11 1 shows a discontinuous reception (DRX) operation. Specifically, Fig.11 The DRX cycle of a UE in RRC_CONNECTED state is shown.

[0165] The UE may perform DRX operation while executing the processing and / or method according to the implementation mode of the present disclosure. The DRX configuration / operation is defined in the NR specification (e.g., Rel-17). DRX for reducing unnecessary power consumption of the UE has the following features. In DRX, the structure of the UE in the RRC_IDLE state (hereinafter referred to as I-DRX) and the structure of the UE in the RRC_CONNECTED state (hereinafter referred to as C-DRX) are separately defined. The two DRX structures are designed so that the period (e.g., the active time period or the on-duration period) in which the UE expects to receive the DL signal occurs periodically, thereby reducing the unnecessary power consumption of the UE in other periods. In particular, in the case of C-DRX, the starting position of the on-duration period is periodically defined according to the NR Rel-16 specification. In this case, the size of the configured period (i.e., DRX cycle) can be determined / configured by high-layer signaling such as RRC signaling provided by the BS to the UE.

[0166] Reference Fig.11, the DRX cycle includes an on-duration and a DRX opportunity. The DRX cycle defines the time interval between periodic repetitions of the on-duration. The on-duration is the time period during which the UE monitors the PDCCH. When the UE is configured with DRX, the UE performs PDCCH monitoring during the on-duration. When the UE successfully detects the PDCCH during the PDCCH monitoring period, the UE starts the inactivity timer and remains awake. On the contrary, when the UE fails to detect any PDCCH during the PDCCH monitoring period, the UE transitions to a sleep state after the on-duration. Therefore, when DRX is configured, the UE may perform PDCCH monitoring / reception discontinuously in the time domain in the process and / or method according to the implementation of the present disclosure. For example, when DRX is configured, the PDCCH reception timing (e.g., a time slot with a PDCCH search space) may be configured discontinuously according to the DRX configuration in the present disclosure. On the contrary, when DRX is not configured, the UE may perform PDCCH monitoring / reception continuously in the time domain. For example, when DRX is not configured, the PDCCH reception timing (e.g., a time slot with a PDCCH search space) may be configured continuously in the present disclosure. Regardless of whether DRX is configured, PDCCH monitoring may be limited during the time period configured as a measurement gap. DRX configuration information is received through high-layer (e.g., RRC) signaling, and DRX on / off is controlled by DRX commands from the MAC layer. Once DRX is configured, the UE may perform PDCCH monitoring discontinuously, such as Figure 8 shown.

[0167] The following table describes the DRX operation of the UE. Referring to the following table, DRX configuration information is received through high-layer signaling (e.g., RRC signaling), and DRX on / off is controlled by a DRX command from the MAC layer. Once DRX is configured, the UE may perform PDCCH monitoring discontinuously, such as Fig.11 shown.

[0168] [Table 5]

[0169]

[0170] MAC-CellGroupConfig includes configuration information required to configure MAC parameters for a cell group. MAC-CellGroupConfig may also include DRX configuration information. For example, when defining DRX, MAC-CellGroupConfig may include the following information.

[0171] -drx-OnDurationTimer value: Configure the duration when the DRX cycle starts.

[0172] -drx-SlotOffset value: configures the delay before starting drx-onDurationTimer.

[0173] - Value of drx-InactivityTimer: Duration after the PDCCH opportunity when the PDCCH indicates a new UL or DL ​​transmission by the MAC entity.

[0174] - Value of drxRetransmissionTimerDL (per DL HARQ process except broadcast process): configures the maximum duration until a DL retransmission is received.

[0175] - Value of drxRetransmissionTimerUL (per UL HARQ process): configures the maximum duration until a grant for UL retransmission is received.

[0176] - Value of drx-HARQ-RTT-TimerDL (per DL HARQ process except broadcast process): configures the maximum duration from reception of initial DL transmission to reception of DL assignment for HARQ retransmission.

[0177] - Value of drx-HARQ-RTT-TimerUL (per UL HARQ process): configures the maximum duration from receiving a grant for an initial UL transmission to receiving a grant for a UL retransmission.

[0178] -drx-LongCycleStartOffset: configures the long DRX cycle and drx-StartOffset, which defines the subframes where the long and short DRX cycles start.

[0179] -drx-ShortCycle (optional): Configure a short DRX cycle.

[0180] -drx-ShortCycleTimer (optional): configures the duration of the short DRX cycle that the UE should follow. For example, the value of the multiple of the short DRX cycle can be configured by drx-CycleTimer. For example, the value of n can correspond to n*drx-ShortCycle.

[0181] If the DRX group is in the active time, the UE may perform PDCCH monitoring on the service cells within the DRX group. In this case, the DRX group refers to a group of service cells configured by RRC and having the same DRX active time. When DRX is configured, the active time of the service cells in the DRX group includes i) the time when the drx-onDurationTimer or drx-InactivityTimer configured for the DRX group is running; or ii) the drx-RetransmissionTimerDL or drx-RetransmissionTimerUL is running on any service cell in the DRX group; or the ra-ContentionResoultionTimer or msgB-RsponseWindow is running; or the time when no PDCCH indicating a new transmission of the C-RNTI sent to the MAC entity of the UE is received after successfully receiving a random access response to a random access preamble that was not selected by the MAC entity among the contention-based random access preambles.

[0182] Fig.12 The configuration of the long DRX cycle and the short DRX cycle is shown. Specifically, Fig.12 The case where drx-ShortCycleTimer is set to 2 is shown.

[0183] The BS may configure a long DRX cycle and an additional short DRX cycle that is shorter than the long DRX cycle. If the short DRX cycle is not configured, the UE may follow the long DRX cycle. When the short DRX cycle is configured, the BS may set the duration of the long DRX cycle to a positive integer multiple of the short DRX cycle. If there is no data activity during the on-duration of the long DRX cycle, the UE may follow the long DRX cycle as if the short DRX cycle was not configured. If there is data activity during the on-duration of the long DRX cycle, for example, while drx-onDurationTimer is running, the UE switches to the short DRX cycle and follows the short DRX cycle for a specific time period (for example, while drx-ShortCycleTimer is running). Reference Fig.12 If there is no data activity during the time when the UE follows the short DRX cycle, for example, if there is no data activity during the period defined by drx-ShortCycleTimer*drx-ShortCycle, the UE switches from a short DRX cycle to a long DRX cycle, each having a duration of drx-ShortCycleTimer.

[0184] Fig.13 FIG. 4 shows SIB1 transmission in a 3GPP-based system. Fig.13 In, PSIB1 Indicates the transmission periodicity or transmission repetition periodicity of SIB1. In addition, SIB1 PDSCH indicates the PDSCH carrying SIB1, and SIB1 PDCCH indicates the PDCCH in the DCI format carrying the scheduling SIB1 PDSCH.

[0185] According to the current 5G specifications, Fig.13 In , as part of the minimum system information required for cell access, SIB1 is sent on DL-SCH with a periodicity of 160ms or a variable transmission repetition periodicity within 160ms. The default transmission repetition periodicity of SIB1 is 20ms, but the actual transmission repetition periodicity depends on the network implementation. For SSB and CORESET multiplexing pattern 1, the transmission repetition period of SIB1 is 20ms. For SSB and CORESET multiplexing pattern 2 / 3, the transmission repetition period of SIB1 is the same as the SSBI period.

[0186] The PDCCH monitoring timing at which the UE attempts to decode the SIB1 PDCCH may be determined based on information in the MIB (e.g., pdcch-ConfigSIB1). For example, during a cell search, if the UE determines based on the MIB that a Type0-PDCCH CSS set exists, the UE may determine the number of consecutive RBs and the number of consecutive symbols of the CORESET of the Type0-PDCCH CSS set from controlResourceSetZero in pdcch-ConfigSIB1. The UE may also determine the PDCCH monitoring timing from searchSpaceZero in pdcch-ConfigSIB1. For example, for an SSB with index i, the system frame number (SFN) of the frame of the relevant CORESET may be provided by searchSpaceZero, and the SFN C ; and SFN C The corresponding frame includes the first time slot of the Type-0 monitoring opportunity, time slot n0; and a combination of parameter values ​​required to determine the index of the first symbol of the corresponding CORESET in time slot n0.

[0187] The UE may monitor the Type0-PDCCH CSS set in the PDCCH monitoring opportunity to detect the SIB1 PDCCH. The UE may determine the frequency resource allocation and time resource allocation of the SIB1 PDSCH from the DCI carried by the SIB1 PDCCH. The UE may receive / decode the SIB1 based on the frequency resource allocation and time resource allocation.

[0188] When the UE has no ongoing data transmission / reception, the UE enters RRC_IDLE or RRC_INACTIVE to save power. When DL data for the UE arrives at the network, the network sends a paging message on a paging occasion (PO) to trigger the RRC setup process and the RRC connection recovery process. PO refers to a set of PDCCH monitoring opportunities and may consist of multiple time slots (e.g., subframes or OFDM symbols). DCI with a CRC scrambled with P-RNTI may be sent on the PO. In multi-beam operation, the UE assumes that the same paging message is repeated in all transmitted beams. The paging message is the same for both paging initiated by the radio access network (RAN) and paging initiated by the core network (CN). A paging frame (PF) is a radio frame and may contain one or more POs or the starting point of a PO. The UE monitors one paging occasion (PO) per DRX cycle. The PF and PO used for paging can be determined by a predetermined equation. For example, in some implementations, the system frame number (SFN) of the PF may be determined by (SFN+PF_offset) mod T = (Tdiv N) * (UE_ID mod N), and the index i_s indicating the index of the PO may be determined by i_s = floor(UE_ID) mod Ns, where T is the DRX cycle of the UE and is determined by the shortest of the UE-specific DRX value and / or the default DRX value broadcast in the system information, N is the total number of paging frames in T, Ns is the number of paging occasions used for the PF, PF_offset is an offset for PF determination, and UE_ID is a value determined based on the 5G-S-TMSI. The following parameters may be signaled in SIB1: a parameter related to the number of POs per paging frame, Ns; ​​a parameter for deriving the total number of paging frames in T, nAndPagingFrameOffset; a parameter related to the number of PDCCH monitoring occasions corresponding to SSBs in the PO, nrofPDCCH-MonitoringOccasionsPerSSB-InPO; and the length of the default DRX cycle. The values ​​of N and PF_offset are derived from the parameter nAndPagingFrameOffset. The PDCCH monitoring occasion for paging is determined based on the following parameters: a parameter indicating the first PDCCH monitoring occasion for paging for each PO of the PF, firstPDCCH-MonitoringOccasionOfPO; and a parameter nrofPDCCH-MonitoringOccasionsPerSSB-InPO. For paging in the initial DL BWP, the parameter firstPDCCH-MonitoringOccasionOfPO may be signaled in SIB1.For paging in a DL BWP other than the initial DL BWP, the parameter firstPDCCH-MonitoringOccasionOfPO may be signaled in the corresponding BWP configuration.

[0189] The UE may use Paging Early Indication (PEI) in RRC_IDLE and RRC_INACTIVE states to reduce power consumption. If the PEI configuration is provided in the system information, a UE in the RRC_IDLE or RRC_INACTIVE state supporting PEI may monitor the PEI using the PEI parameters in the system information. The UE monitors one PEI opportunity per DRX cycle. A PEI opportunity (PEI-O) is a set of PDCCH monitoring opportunities and may consist of multiple time slots (e.g., subframes or OFDM symbols) in which PEI may be sent. In multi-beam operation, the UE assumes that the same PEI is repeated in all transmitted beams. The temporal position of the PEI-O for the UE's PO is determined by a reference point and an offset. The reference point is the start of the reference frame determined by the frame-level offset from the start of the first PF in the PFs associated with the PEI-O (provided by pei-FrameOffset in SIB1), and the offset is the symbol-level offset from the reference point to the start of the first PDCCH MO of the PEI-O (provided by firstPDCCH-MonitoringOccasionOfPEI-O in SIB1). If one PEI-O is associated with the PO of two PFs, the two PFs are consecutive PFs calculated by the parameters PF_offset, T, Ns and N. Details of PEI can be found in 3GPP TS 38.304 and 3GPP TS 38.213.

[0190] Paging DRX is defined, which requires a UE in RRC_IDLE or RRC_INACTIVE state to monitor the paging channel during one PO per DRX cycle. The network may configure the following paging DRX cycles: i) for CN initiated paging, a default cycle is broadcast in the system information, ii) for CN initiated paging, a UE specific cycle may be configured via non-access stratum (NAS) signaling, iii) for RAN initiated paging, a UE specific cycle may be configured via RRC signaling. The UE uses the shortest cycle among the applicable DRX cycles. For example, a UE in RRC_IDLE may use the shortest of the first two cycles mentioned above, and a UE in RRC_INACTIVE may use the shortest of the three cycles.

[0191] Energy saving of BS is significantly considered in wireless communication systems including 3GPP due to its potential contribution to building environmentally friendly networks by reducing carbon emissions and cutting the operating expenditure (OPEX) of communication operators. In particular, as the demand for high transmission rates continues to escalate with the emergence of 5G communications, BSs need to be equipped with a larger number of antennas and provide services in wider bandwidths and frequency bands. According to recent studies, the energy cost of BSs has reached as high as 20% of the total OPEX. Due to the increased attention to BS energy saving, 3GPP NR Release 18 approved a new research project called "Network Energy Saving Research". For example, in order to enhance the energy-saving capabilities in terms of transmission and reception of BS, this study investigates how to use potential support / feedback from UE and potential UE support information based on one or more network energy-saving technologies with finer adaptive granularity to dynamically and / or semi-statically achieve more efficient transmission and / or reception operations in time, frequency, space and power domains.

[0192] Hereinafter, implementations of the present disclosure will be described with respect to methods and processes for BS energy saving in the time domain by reducing transmission of common signals / channels such as SSB, SIB1, other SI and / or paging, or by sending common signals / channels in an on-demand manner.

[0193] According to some implementations of the present disclosure, in a light load situation where the BS has almost no data to send, the BS can save energy by turning off the transmission / reception of specific DL / UL signals and channels within a specific time period or by reducing the amount of frequency resources such as operating BWP. For example, the BS can control the transmission / reception on the carrier / cell based on the scheduling on the carrier / cell. However, considering that the transmission of common signals / channels such as SSB / SIB1 / other SI / paging is crucial for cell selection (reselection), initial access, radio resource management (RRM) measurements, etc., the common signals / channels are regarded as normally open signals / channels that need to be sent periodically. If the BS does not send a signal at all or sends a signal with too long a periodicity, problems may occur in cell detection, time and frequency synchronization, paging, radio link management (RLM) and / or RRM measurements of the UE. As a result, the performance of the UE accessing the corresponding cell may be degraded. Therefore, when the BS intends to drop or reduce the transmission of cell common signals / channels related to cell detection, time and frequency synchronization, paging, RLM and / or RRM measurement of the UE in addition to the signals / channels that the BS can schedule or configure according to the load condition of the BS (e.g., PDCCH / PUSCH / PDSCH / CSI-RS / SRS, etc.) in order to operate in a network energy saving (NES) mode on the cell, a method is needed to minimize the impact on the UE.

[0194] Therefore, in some implementations of the present disclosure, when the BS aims to save energy by reducing the transmission of common signals / channels on a carrier / cell within a specific time period or increasing its transmission periodicity, the BS may configure an alternative carrier / cell on which the UE can receive common signals / channels with a shorter periodicity or send SI and / or paging in an on-demand manner. This approach can achieve BS / network energy saving while minimizing the performance degradation of the UE.

[0195] Hereinafter, operation of a BS in an NES mode for energy saving (ES) may mean that the BS preconfigures a plurality of off periods (i.e., discontinuous transmission (DTX) periods) during a specific time period to turn off transmission of a specific DL signal, and then dynamically indicates one of the off periods to notify that the corresponding DL signal will not be sent during the predefined time period, so as to achieve power consumption reduction for both the BS and the UE. The NES mode may be applied not only to the time domain, but also to the following operations in the frequency domain: BWP switching, dynamic RB adaptation, etc. For the spatial domain, the NES mode may refer to an operation mode in which the BS avoids performing transmission and / or reception on a corresponding antenna port to achieve power consumption reduction for both the BS and the UE when the BS semi-statically or dynamically disables a specific reception antenna port.

[0196] <Method #1> A method of configuring a carrier / cell in which a UE can receive a common signal / channel (e.g., SSB / SIB / paging, etc.) when the BS intends to reduce transmission of the common signal / channel during a specific time period or configures a long periodicity for it to transition to NES mode; and a method of determining whether to transition to NES mode based on feedback from the UE by the BS. Specifically, the following methods can be applied.

[0197] >(1-1) The BS may configure / indicate or broadcast in advance to the UE a period (starting point or duration) of reducing the transmission of common signals / channels or increasing the periodicity on the carrier / cell. The BS may also configure / indicate information about another carrier / cell on which the UE can receive the common signals / channels of the carrier / cell during the corresponding period.

[0198] >(1-2) The BS may repeatedly perform broadcast transmissions about the start of the NES mode, wherein the transmission of common signals / channels on the carrier / cell is reduced or its periodicity is increased. The BS may then receive feedback information (e.g., assistance information) from the UE and determine whether to actually transition to the NES mode.

[0199] >>i. In some implementations, the BS may receive a report from the UE regarding coverage information, service type, location within a cell, SI, or information regarding whether resources need to be measured, and then determine that the periodicity of the common signal / channel needs to be changed.

[0200] >>ii. In some implementations, the BS may poll the UE for the possibility of transitioning to the NES mode via a group common DCI or MAC control element (CE). The BS may then determine whether to transition to the NES mode based on the HARQ-ACK feedback result from the UE.

[0201] >>>iii. In some implementations, the BS may instruct the UE (supporting NES mode) (or the UE with RSRP less than or equal to a specific value) to send a sounding reference signal (SRS) or a specific UL signal / channel on a pre-configured / predetermined specific resource. The BS may then determine whether to transition to NES mode by evaluating the status of the UEs in the cell (e.g., cell edge UEs).

[0202] Hereinafter, the methods mentioned in (1-1) and (1-2) above will be described in more detail. The methods described in (1-1) and (1-2) can be applied independently or in combination.

[0203] In some implementations of the present disclosure, the BS may achieve network energy saving by shutting down or reducing transmission / reception on some cells managed by the BS in the NES mode.

[0204] Fig.14 The process of sending or receiving a common signal / channel according to some implementations of the present disclosure is shown. During a time period outside the NES mode, the BS provides a common signal / channel of the first cell on the first cell with a predetermined first periodicity (S1401). During a time period outside the NES mode, the UE monitors the common signal / channel of the first cell on the first cell with a predetermined first periodicity (S1401). The second cell that sends the common signal / channel of the first cell during the NES mode can be indicated / configured to the UE. When the BS and the UE enter the NES mode (S1403 is yes), the BS can send the common signal / channel of the first cell on the second cell associated with the first cell (S1405), and the UE can monitor the common signal / channel of the first cell on the second cell (S1405). In some implementations, during the time period of the NES mode, the BS can be configured to send the common signal / channel of the first cell on the first cell with a second periodicity longer than the first periodicity. During the time period of the NES mode, the UE can be configured to monitor the common signal / channel of the first cell on the first cell with a second periodicity longer than the first periodicity.

[0205] Fig.15 1 shows common signal / channel opportunities for cells according to some implementations of the present disclosure. Fig.15In the example of , it is assumed that cell A is a cell that changes the transmission periodicity of the common signal / channel during the NES mode, and cell B is a cell that does not change the transmission periodicity of the common signal / channel X during the NES mode. Fig.15 In, P A_X_1 represents the periodicity of the (transmission / reception) opportunity of the common signal / channel X of cell A when not in NES mode, P A_X_2 represents the periodicity of the (transmission / reception) opportunity of the common signal / channel X of cell A in NES mode, where P A_X_2 P A_X_1 In addition, P B_X represents the periodicity of the (transmission / reception) timing of the common signal / channel X of cell B. In this case, P A_X_1 and P B_X can be the same or different. In some implementations, P A_X_2 It can be P A_X_1 A positive integer multiple of . Common signal / channel X may be SSB, SIB1, other SI (i.e., SIB other than SIB1) or paging. The (transmission / reception) periodicity and / or timing of common signal / channel X may be defined (in the specification) according to the type of the corresponding common signal / channel or configured by the BS. Fig.15 It is shown that the transmission / reception periodicity of the common signal / channel X of cell A during the NES mode becomes longer than that during the NES mode. However, the transmission / reception of the common signal / channel X on cell A can be omitted during the NES mode. In addition, Fig.15 It is shown that the timing of the common signal / channel X on cell A in NES mode is determined based on the last timing of the common signal / channel X in non-NES mode. A_X_2 It may be applied after entering the NES mode or after a certain period of time after entering the NES mode. In some implementations, while cell A is operating in the NES mode, the BS may transmit the common signal / channel X of cell A on cell B. In some implementations, considering the possibility of NES mode transition configuration / indication loss, regardless of whether the NES mode is applied to cell A, the BS may transmit the common signal / channel X of cell A on cell B. When the common signal / channel of cell A is transmitted on cell B, the periodicity of the common signal / channel of cell A on cell B may be the same as or different from when the common signal / channel of cell A is transmitted on cell A. The periodicity of the common signal / channel of cell A may be defined or configured as P on cell B. A_X_2 Alternatively, the periodicity of the common signal / channel of cell A may be defined or configured to be equal to the periodicity P of the common signal / channel of cell B. B_X Same or P B_X A positive integer multiple of .

[0206] In some implementations of the present disclosure, the BS may configure / indicate an absolute or relative time about when to transition to NES mode and change the transmission periodicity of a common signal / channel. For example, the BS may configure / indicate to the UE that the UE transitions to NES mode and changes the SFN of the transmission periodicity of a common signal / channel. As another example, the BS may transition to NES mode after a specific time has passed from the broadcast signal that transmits the configuration / indication to transition to NES mode or after a specific time has passed from a specific transmission opportunity of a common signal / channel to change the transmission periodicity (e.g., the last transmission opportunity before the configuration / indication transitions to NES mode). The specific time may be configured / indicated to the UE by the BS, or specified in the specification / system. As another example, the BS may additionally indicate the absolute time by providing an offset value (e.g., in time slots or symbols) of a specific SFN. Alternatively, the BS may indicate the relative time by providing a specific offset (e.g., in time slots or symbols) of the time of the indication of transitioning from sending / receiving to NES mode.

[0207] When the BS arbitrarily reduces the transmission of common signals / channels such as SSB / SIB or sends common signals / channels with too long a transmission periodicity, problems may occur in the cell detection and time and frequency synchronization of the UE. Therefore, when the BS arbitrarily reduces the transmission frequency of common signals / channels such as SSB / SIB or configures a long transmission periodicity for them, a method for providing common signals / channels through an alternative path is needed. In some implementations of the present disclosure, when the BS intends to transition to NES mode within a specific time period in order to reduce the transmission of common signals / channels (e.g., SSB / SIB / paging, etc.) or configure a longer periodicity, the BS may configure / indicate information about the time period for applying the NES mode. In addition, by configuring the UE with other carriers / cells (e.g., Fig.15 In the case of a cell B in the NES mode, the BS can not only minimize the impact of the corresponding carrier / cell that reduces the reception opportunity of the common signal / channel during the time period of the NES mode on the UE performance, but also reduce its own energy consumption. In this case, the carrier / cell (e.g., Fig.15 Another carrier / cell (e.g., Fig.15 Cell B in the NES mode may also carry a carrier / cell operating in NES mode (e.g., Fig.15SI on cell A in the group. On the other hand, information about the time period for the BS / UE to operate in the NES mode (e.g., starting point and duration) and information about the carrier / cell where the UE receives the common signal / channel (e.g., cell index) can be semi-statically pre-configured by high-level signaling such as RRC signaling. Alternatively, the BS can configure multiple candidates obtained by combining the starting point, duration and specific carrier / cell index of the NES mode through RRC (i.e., RRC signaling), and then dynamically indicate one of the multiple candidates in the group common DCI. In this case, the starting point of the NES mode can be specified or indicated as an absolute or relative time. For example, the BS can assign or indicate the SFN at which the NES mode starts to the UE. As another example, the BS can be converted to the NES mode after a specific time has passed from the time of sending the broadcast signal that configures / indicates the conversion to the NES mode or after a specific time has passed from the specific transmission opportunity of the common signal / channel to change the transmission periodicity (e.g., the last transmission opportunity before the configuration / indication is converted to the NES mode). The specific time can be configured / indicated to the UE by the BS, or specified in the specification / system. As another example, the BS may additionally indicate an absolute time by providing an offset value (e.g., in time slots or symbols) for a particular SFN. Alternatively, the BS may indicate a relative time by providing a specific offset (e.g., in time slots or symbols) for the indicated time of transitioning from transmit / receive to NES mode.

[0208] When the BS intends to operate in NES mode within a specific period to save energy, the BS may need to urgently send / receive data in the cell or there may be UEs that need to receive specific common signals / channels for measurement or SI acquisition. In addition, considering the following problems: the configuration / indication / notification of the transition to NES mode is lost; and the UE fails to decode the corresponding transition configuration / indication / notification, the BS may repeatedly send a signal / channel that notifies the UE to transition to NES mode multiple times before transitioning to NES mode, and then receive feedback from the UE to determine whether to transition to NES mode at the actual indicated time. The feedback provided by the UE may include information about coverage, information about the type of service (e.g., information about whether high throughput is required), information about the location of the UE in the cell (e.g., information about whether the UE is located at the edge of the cell), information about whether there is a demand for SI or measurement resources, or any combination thereof. Upon receiving the corresponding feedback information, the BS may cancel the transition to NES mode, that is, the BS may not continue to transition to NES mode at the time indicated by the BS as the starting point of the NES mode. Alternatively, if the BS receives a feedback indication that the UE needs a specific common signal / channel (e.g., a specific SI), the corresponding common signal / channel may be excluded from the transmission reduction target.

[0209] In some implementations, before transitioning to NES mode, the BS may send a group-common DCI to the UE to poll whether the transition to NES mode is acceptable. Based on the HARQ-ACK feedback information received from the UE (e.g., ACK or NACK (A / N), ACK only, or NACK only), the BS may determine whether to actually perform the NES transition at the transition time point indicated / configured by the BS. Alternatively, by instructing the UE to send SRS (SR, RACH, etc.) on pre-configured resources (e.g., only for advanced UEs supporting NES mode or UEs whose RSRP in the cell is lower than a predefined / pre-configured threshold (e.g., based on the RSRP of a specific RS (e.g., SSB / CSI-RS) configured by the BS), the BS may evaluate the status of UEs in the cell (e.g., cell edge UEs) to determine whether to transition to NES mode.

[0210] In some implementations, in order to transition to NES mode, the BS may perform feedback polling by sending a group common DCI to the UE in the cell. The UE may provide feedback about the possibility of transition by sending A / N, ACK only, or NACK only according to a predefined agreement (e.g., defined in the specification) or based on the configuration / instruction provided by the BS. For example, the UE may send ACK to notify the BS that the transition to NES mode is acceptable. If the UE has data to send, the UE may send NACK to provide auxiliary information to the BS. Alternatively, the UE may be configured to always send only NACK (or only ACK) to prevent the BS from transitioning to NES mode only when the UE has data to send or receive. In contrast, the UE may be configured to always send only NACK (or only ACK) to indicate that the transition to NES mode is acceptable. In this case, the PUCCH resources for only ACK or only NACK can be configured in a cell-specific or UE group-common manner. For example, in the case of only ACK, the UE may send feedback only when the UE decodes the DCI / data as ACK or the UE accepts the NES transition of the BS. Otherwise, the UE may not send feedback. On the contrary, in the case of NACK only, the UE may send feedback only when the result of the UE's decoding of the DCI / data is NACK or the UE does not accept the NES transition of the BS. Otherwise, the UE may not send feedback.

[0211] For specific signals / channels (e.g., common signals / channels such as SSB / SIB1), if the UE has data to send or receive (e.g., if the UE needs to perform periodic SSB measurements for RLM or RRM), the UE may also send an ACK or NACK. For example, when the BS transitions to NES mode, common signals / channels such as SSB / SIB1 may be sent with a long periodicity or omitted entirely during NES mode operation. Therefore, if the UE needs to receive SSB or SIB1 at the time of receiving the group common DCI sent from the BS for polling, the UE may send an ACK or NACK to the BS to assist the BS in determining the transition to NES mode. On the other hand, when a predetermined condition is met, for example, when the RSRP within the cell drops below a predefined / preconfigured threshold, the UE may send an ACK or NACK via SRS or PUCCH or send a preconfigured / predefined UL signal / channel (e.g., RACH), regardless of whether the UE has UL data to send. Therefore, the BS may evaluate the status of UEs (e.g., cell edge UEs) within the cell to determine whether to transition to NES mode.

[0212] In some implementations of the present disclosure, the NES mode configuration applied to the cell may be provided by the cell itself or by one of the serving cells of the UE.

[0213] <Method #2> A method of sending / receiving common signals / channels (eg, SIB1 / paging, etc.) on demand

[0214] >(2-1) When the BS sends SIB1 PDCCH by beam sweeping in multiple beam directions and when the UE informs its need for SIB1 via RACH using preconfigured / predefined resources, the BS sends SIB1 PDCCH and / or SIB1 PDSCH only in the beam direction related to the RACH.

[0215] >>i. If the BS is able to include information triggering on-demand SIB1 on the SIB1 PDCCH, the BS may transmit the SIB1 PDCCH across all beams and transmit the SIB1 PDSCH only through a beam in which a RACH exists among the beams.

[0216] >(2-2) When the DCI carried by the SIB1 PDCCH contains scheduling information for the SIB1 PDSCH (and also includes configuration information about the RACH for requesting on-demand SIB1), if the UE sends a RACH, the SIB1 PDSCH is sent / received at a relative position with reference to the corresponding RACH timing or a specific reference timing (based on the scheduling information provided by the DCI).

[0217] >>i. When SIB1 PDCCH (or any PDCCH including RACH configuration information but without scheduling information for SIB1 PDSCH) provides only configuration information about RACH for requesting on-demand SIB1 but without PDSCH scheduling information, if the UE sends RACH, the BS sends (normal) SIB1 PDCCH and SIB1 PDSCH scheduled by the SIB1 PDCCH.

[0218] >(2-3) When the paging DCI contains the paging PDSCH scheduling information, if the UE sends a RACH, the paging PDSCH is sent / received at a relative position with reference to the corresponding RACH timing or reference timing (based on the scheduling information provided by the DCI).

[0219] >>i. When the paging DCI contains only information about the existence of paging but no PDSCH scheduling information, if the UE sends a RACH (where the resources for sending the corresponding RACH can be configured / indicated by the paging DCI), the BS sends a (normal) paging DCI and a paging PDSCH scheduled by the paging DCI.

[0220] >(2-4) For paging reception of the UE, when RACH resources for requesting on-demand paging are pre-configured, paging is requested in the non-broadcast state using the configured RACH resources based on an indication of whether the corresponding paging information is in a broadcast state (e.g., in a state where the paging information can be sent on a PO in a pre-configured PF) or in a non-broadcast state (e.g., in a state where the BS enters the NES mode and sends paging in an on-demand manner only upon request by the UE). Alternatively, whether the paging information is in a broadcast state is implicitly indicated by whether there is a RACH resource configured for requesting on-demand paging.

[0221] >(2-5) The UE may determine whether to attempt paging reception after confirming the ACK for the on-demand request.

[0222] >>i. In this case, for ACK confirmation, ACK information may be included in the paging PDCCH. Alternatively, ACK confirmation may be replaced by reception of the paging PDCCH.

[0223] >>ii. Unlike the conventional paging PDCCH which is repeated on multiple beams by beam sweeping, the on-demand paging PDCCH does not require transmission by beam sweeping because the UE informs the SSB associated with the RACH transmission via RACH transmission. In other words, the BS transmits the on-demand paging PDCCH in the corresponding beam direction where the RACH is received.

[0224] >>iii. After performing RACH transmission, the UE determines whether to monitor the paging early indication / wake-up signal (PEI / WUS) on the corresponding beam according to the configuration / instruction / agreement.

[0225] Hereinafter, the methods mentioned above in (2-1) and (2-5) will be described in more detail. The methods described in (2-3) and (2-5) can be applied independently or in combination.

[0226] In order to schedule SIB1 including basic information of cell access and SSB, Type#0CSS (i.e., Type0-PDCCHCSS) also needs to be sent periodically. Therefore, from the perspective of BS energy saving, methods of reducing the transmission of Type#0CSS or extending its periodicity may also be considered. The periodicity of Type#0CSS is 20ms (for SSB / CORESET 0 multiplexing pattern 1 (i.e., SSB and CORESET multiplexing pattern 1)), and the periodicity of Type#0CSS is the same as the SSB periodicity (for SSB / CORESET multiplexing pattern 2 or 3). Generally, since monitoring only three to five SSBs may be sufficient to decode SIB1 by obtaining fine synchronization (may depend on UE implementation), the Type#0CSS transmission associated with the remaining SSBs may be considered unnecessary and regarded as a waste of energy. Therefore, for example, if the UE is allowed to achieve synchronization with only three SSBs for SSB / CORSET0 multiplexing pattern 2 or 3 and perform decoding of Type#0CSS, the actually required Type#0CSS periodicity may be set to about three times the SSB periodicity. Therefore, due to the reduced Type#0 CSS transmission, the BS can save energy. Therefore, if the transmission of common signals / channels such as SIB1 PDCCH, SIB1 PDSCH, paging PDCCH and / or paging PDSCH is reduced or if common signals / channels are sent on demand according to the request of the UE, both the BS and the UE can be assisted in energy saving.

[0227] Instead of sending SIB1 PDCCH and SIB1 PDSCH in all beam directions based on beam sweeping in which the beam (or beam direction) of the radio signal varies over time, the BS may send SIB1 PDCCH only based on beam sweeping. If the UE informs the need for SIB1 PDCCH / PDSCH via RACH using preconfigured / predefined resources, the BS may send SIB1 PDCCH / PDSCH only in the beam direction associated with RACH for energy saving. Alternatively, if the BS is allowed to load information that triggers on-demand SIB1 on SIB1 PDCCH, the BS may send SIB1 PDSCH only on the beam associated with RACH while sending SIB1 PDCCH in all beam directions through beam sweeping.

[0228] When the SIB1 PDCCH includes scheduling information for the SIB1 PDSCH (including RACH configuration information for requesting on-demand SIB1), if the UE sends a RACH (in this case, information about RACH resources associated with the SIB1 PDCCH may be predefined in the specification or indicated by the SSB), the SIB1 PDSCH may be sent / received at a relative position with reference to the corresponding RACH timing or a specific reference timing (based on the scheduling information provided by the DCI carried via the SIB1 PDCCH). As another example, when the (SIB1) PDCCH includes only RACH configuration information for requesting on-demand SIB1 without PDSCH scheduling information, if the UE sends a RACH (in this case, information about relevant RACH resources may be provided by the corresponding PDCCH), the BS may send a (normal) SIB1 PDCCH and a SIB1 PDSCH scheduled by the SIB1 PDCCH after receiving the RACH. The UE may expect to receive the (normal) SIB1 PDCCH associated with the sent RACH (in the SSB or beam direction).

[0229] A method similar to SIB1 can also be applied to paging DCI and paging PDSCH. For example, when the paging DCI includes scheduling information for the paging PDSCH, if the UE sends a RACH (in this case, information about the RACH resources associated with the paging DCI may be predefined in the specification or indicated by the SSB), the paging PDSCH may be sent / received at a relative position with reference to the corresponding RACH timing or a specific reference timing (based on the scheduling information provided by the paging DCI). As another example, when the paging DCI only contains information about the presence of paging but no PDSCH scheduling information, if the UE sends a RACH (in this case, information about the relevant RACH resources may be provided by the paging DCI), the BS may send a (normal) paging DCI and a paging PDSCH scheduled by the paging DCI. The UE may expect to receive a (normal) paging DCI associated with the sent RACH (in the SSB or beam direction).

[0230] For paging reception of a UE, when a RACH resource for requesting on-demand paging is configured, based on an indication or configuration indicating whether the corresponding paging information is in a broadcast state (e.g., in a state where the paging information can be sent on a PO in a preconfigured PF) or in a non-broadcast state (e.g., in a state where the BS enters an NES mode and sends paging in an on-demand manner only when the UE requests it), the UE may request paging in a non-broadcast state (or when the indication / configuration is to send the paging information after the on-demand processing) using the configured RACH resource. The UE may determine whether to attempt paging reception after confirming an ACK for the on-demand request. In this case, for ACK confirmation, ACK information may be included in the paging PDCCH. Alternatively, the ACK confirmation may be replaced by the reception of the paging PDCCH. Alternatively, whether the paging information is in a broadcast state may be implicitly indicated by whether there is a RACH resource configured for requesting on-demand paging. For example, if RACH resources are configured for requesting on-demand paging, the UE may implicitly know that the BS sends paging only when the UE sends RACH because the BS is currently operating on-demand paging, not broadcast paging.

[0231] For on-demand paging PDCCH, unlike the traditional paging PDCCH sent based on beam sweeping, the UE informs the associated SSB associated through RACH transmission. Therefore, the BS can send on-demand paging PDCCH in the beam direction where the RACH is received. In addition, after sending the RACH, the UE can determine whether to monitor PEI / WUS on the corresponding beam according to the configuration / indication / agreement.

[0232] In addition, in the above method, if the SSB group is predefined by grouping one or more SSB indexes, and if the UE sends a request for on-demand SSB / paging (e.g., WUS) using a specific UL signal / channel, the BS may send not only a specific SSB related to the request for on-demand SIB or paging from the UE, but also the entire SSB group including the corresponding SSB. For example, when SSB group #1 is configured to include SSB indexes #0, #1, and #2 and SSB group #2 is configured to include SSB indexes #3, #4, and #5, if the UE expects to receive SIB1 or paging corresponding to SSB index #3, the UE may send WUS using the UL signal and channel corresponding to the preconfigured / predefined SSB group #2. Upon receiving the WUS, the BS may send SIB1 or paging corresponding to all SSB indexes #3, #4, and #5 associated with SSB group #2.

[0233] The above-mentioned method #1 and method #2 may be applied independently or in combination. For example, in some implementations, if a specific cell operates in NES mode within a specific time period according to method #1, and if other cells configured / instructed to send common signals / channels for the specific cell also operate in NES mode, method #2 may be applied. As another example, in some implementations, a cell or a UE may be configured with an NES mode according to method #1 or an NES mode according to method #2. When the NES mode according to method #1 is configured, the BS and the UE may operate according to method #1. When the NES mode according to method #2 is configured, the BS and the UE may operate according to method #2.

[0234] According to the above-mentioned method #1 and / or method #2, the BS can schedule the UE to perform transmission / reception on other cells during the NES mode, rather than the cell where the timing of the common signal / channel needs to be controlled, so as to minimize the transmission / reception on the cell and ensure a relatively longer duration of operation in the sleep mode (or inactive state), thereby achieving energy saving for both the BS and the UE.

[0235] In an LTE-based system, the BS may use the following operations: cell on / off, which allows the BS to adaptively turn on and off DL transmission on a cell. For cells that perform on / off, only periodic discovery signals including CRS, PSS, SSS, and non-zero power CSI-RS for specific antenna ports may be sent. For frame structure type 1 applicable to both full-duplex and half-duplex frequency division duplex (FDD), the period of discovery signal opportunities for which discovery signals for cells are expected to exist may have a duration of 12 OFDM symbols within one to five consecutive subframes; for frame structure type 2 applicable only to time division duplex (TDD), it has a duration of two to five consecutive subframes; for frame structure type 3 applicable to authorized assisted access (LAA) secondary cell operation with normal CP, it has a duration of a single non-empty subframe. The periodicity or position of the subframes in which the UE can assume discovery signal opportunities is determined for each frame structure type. According to the cell on / off in the conventional system (e.g., LTE), even if the cell is turned off, a discovery signal consisting of a periodic CRS is periodically sent, and it is difficult to dynamically turn on / off the signal / channel at the symbol level within a specific time period. The BS may configure a cell that is not used for data transmission within a specific time period as an SCell that is deactivated for the UE. When the SCell is deactivated, the UE does not send the SRS configured on the corresponding SCell, does not send the UL-SCH on the corresponding SCell, does not perform PDCCH monitoring on the corresponding SCell, and does not perform UE operations related to the deactivated SCell (e.g., does not send RACH on the corresponding SCell). Even if a specific cell is an SCell deactivated for the UE, data transmission on the specific cell may occur for other UEs. Therefore, for a cell deactivated for any UE, the BS may need to perform transmission / reception on the cell for other UEs unless the BS instructs all UEs using the cell as a serving cell to perform deactivation. In addition, even if the cell is deactivated, common signals / channels such as SSB / SIB1 / other SI / paging may need to be continuously sent on the corresponding cell for cell detection and time and frequency synchronization of other UEs. According to some implementations of the present disclosure, the common signal / channel of the cell can be dynamically turned on / off within a specific time period and / or at the symbol level, which allows the common signal / channel of the cell to be controlled faster than the traditional cell turn-on / off operation. In addition, since the BS can turn on and off the transmission of the common signal / channel of the cell with finer resolution (e.g., at the symbol level), the BS can flexibly and quickly adjust the periodicity of the timing of the common signal / channel according to the load state of the BS. In addition, according to some implementations of the present disclosure, the cell detection, time and frequency synchronization, and paging of the UE that adjusts the periodicity of the common signal / channel are provided by other cells.Furthermore, according to some implementations of the present disclosure, the BS may reduce opportunities for sending common signals / channels on a cell without deactivating the cell or shutting down the cell for each UE.

[0236] Fig.16 A flow of DL signal reception by a UE according to some implementations of the present disclosure is shown.

[0237] The UE may perform operations according to some implementations of the present disclosure in association with DL signal reception. The UE may include: at least one transceiver; at least one processor; and at least one computer memory, which is operatively connectable to the at least one processor and stores instructions, which when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. A processing device for a UE may include: at least one processor; and at least one computer memory, which is operatively connectable to the at least one processor and stores instructions, which when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer-readable (non-volatile) storage medium may store at least one computer program including instructions, which when executed by at least one processor cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer program or computer program product may include instructions, which are recorded on at least one computer-readable (non-volatile) storage medium and when executed, cause (at least one processor) to perform operations according to some implementations of the present disclosure.

[0238] The method performed by the UE or the operation of the UE, the processing device, the computer-readable (non-volatile) storage medium and / or the computer program product may include: monitoring a common DL signal of a first cell on a first cell in a first mode with a first periodicity (S1601); receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and based on a transition from the first mode to the second mode (S1603), monitoring a common DL signal of the first cell on the second cell within a first time period (S1605).

[0239] In some implementations, the method or operation may further include monitoring the common DL signal of the first cell within the first time period with a second periodicity that is longer than the first periodicity.

[0240] In some implementations, the common DL signal of the first cell may be the SI of the first cell.

[0241] In some implementations, the common DL signal of the first cell may be a paging message.

[0242] In some implementations, the common DL signal of the first cell may be an SSB consisting of a PSS of the first cell, an SSS of the first cell, and a PBCH of the first cell.

[0243] In some implementations, the method or operations may include: detecting a group-common DCI format related to transitioning to the second mode; and transitioning from the first mode to the second mode based on the group-common DCI format.

[0244] In some implementations, the information about the time period of the second mode may include configuration for a plurality of time periods.The group common DCI format may include information indicating a first time period among the plurality of time periods.

[0245] In some implementations, the method or operation may further include sending an ACK or NACK for transitioning to the second mode based on the group common DCI format.

[0246] In some implementations, the method or operation may include: receiving a configuration related to a third mode, wherein the configuration related to the third mode includes information about a time period of the third mode; based on a transition from the first mode to the third mode, monitoring the PDCCH of SIB1 of the first cell on the first cell within a second time period; based on detecting the SIB1 PDCCH of SIB1, sending a SIB1 request on a RACH resource related to the SIB1 PDCCH; and based on the transmission of the SIB1 request, receiving a PDSCH carrying SIB1.

[0247] Fig.17 A flow of DL signal transmission by a BS according to some implementations of the present disclosure is shown.

[0248] The BS may perform operations according to some implementations of the present disclosure in association with DL signal transmission. The BS may include: at least one transceiver; at least one processor; and at least one computer memory, which is operatively connectable to the at least one processor and stores instructions, which when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. A processing device for a BS may include: at least one processor; and at least one computer memory, which is operatively connectable to the at least one processor and stores instructions, which when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer-readable (non-volatile) storage medium may store at least one computer program including instructions, which when executed by at least one processor cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer program or computer program product may include instructions, which are recorded on at least one computer-readable (non-volatile) storage medium and when executed, cause (at least one processor) to perform operations according to some implementations of the present disclosure.

[0249] The method performed by the BS or the operation of the BS, the processing device, the computer-readable (non-volatile) storage medium and / or the computer program product may include: sending a common DL signal of the first cell on the first cell in a first mode with a first periodicity (S1701); receiving a configuration related to the second mode, wherein the configuration related to the second mode includes information about the time period of the second mode and cell information about the second cell associated with the first cell; and based on the transition from the first mode to the second mode (S1703), sending a common DL signal of the first cell on the second cell within the first time period (S1705).

[0250] In some implementations, the method or operation may include sending a common DL signal of the first cell within the first time period with a second periodicity that is longer than the first periodicity.

[0251] In some implementations, the common DL signal of the first cell may be the SI of the first cell.

[0252] In some implementations, the common DL signal of the first cell may be a paging message.

[0253] In some implementations, the common DL signal of the first cell may be an SSB consisting of a PSS of the first cell, an SSS of the first cell, and a PBCH of the first cell.

[0254] In some implementations, the method or operation may further include sending a group common DCI format related to transitioning to the second mode.

[0255] In some implementations, the method or operations may include transitioning from the first mode to the second mode based on transmission of a group common DCI format.

[0256] In some implementations, the information about the time period for the second mode may include configuration for a plurality of time periods.The group common DCI format may include information indicating a first time period among the plurality of time periods.

[0257] In some implementations, the method or operation may further include receiving an ACK or NACK for transitioning to the second mode based on the group common DCI format.

[0258] In some implementations, the method or operation may include: sending a configuration related to the third mode, wherein the configuration related to the third mode includes information about a time period for the third mode; based on the transition from the first mode to the third mode, sending a SIB1 PDCCH of SIB1 of the first cell on the first cell within a second time period; receiving a SIB1 request on a RACH resource related to the SIB1 PDCCH; and based on the reception of the SIB1 request, sending a PDSCH carrying SIB1.

[0259] The examples of the present disclosure as described above have been presented to enable those of ordinary skill in the art to implement and practice the present disclosure. Although the present disclosure is described with reference to the examples, those skilled in the art may make various modifications and changes in the examples of the present disclosure. Therefore, the present disclosure is not intended to be limited to the examples set forth herein, but to conform to the widest scope consistent with the principles and features disclosed herein.

[0260] Implementations of the present disclosure may be used in a BS, a UE, or other devices in a wireless communication system.

Claims

1. A method for receiving a downlink signal by a user equipment UE in a wireless communication system, the method comprising the following steps: monitoring a common downlink signal of the first cell in a first mode on a first cell with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and Based on the transition from the first mode to the second mode, the common downlink signal of the first cell is monitored on the second cell for a first time period.

2. The method according to claim 1, wherein: The common downlink signal of the first cell is system information of the first cell.

3. The method according to claim 1, wherein: The common downlink signal of the first cell is a paging message.

4. The method according to claim 1, wherein: The common downlink signal of the first cell is a synchronization signal block SSB consisting of a primary synchronization signal PSS of the first cell, a secondary synchronization signal SSS of the first cell and a physical broadcast channel PBCH of the first cell.

5. The method according to claim 1, comprising the steps of: detecting a group common downlink control information (DCI) format associated with transitioning to said second mode; and Transitioning from the first mode to the second mode based on the set of common DCI formats.

6. The method according to claim 5, wherein: The information about the time period for the second mode includes configuration for a plurality of time periods, and The group common DCI format includes information about the first time period among the multiple time periods.

7. The method according to claim 5, further comprising the steps of: An acknowledgement ACK or a negative ACK NACK for transitioning to the second mode is sent based on the set common DCI format.

8. The method according to claim 1, comprising the steps of: receiving a configuration related to a third mode, wherein the configuration related to the third mode includes information about a time period for the third mode; Based on the transition from the first mode to the third mode, monitoring a physical downlink control channel PDCCH of a system information block 1 SIB1 for the first cell on the first cell within a second time period; Based on detecting the SIB1 PDCCH for the SIB1, sending a SIB1 request on a random access channel RACH resource related to the SIB1 PDCCH; and Based on the sending of the SIB1 request, a physical downlink shared channel PDSCH carrying the SIB1 is received.

9. A user equipment UE configured to receive a downlink signal in a wireless communication system, the UE comprising: at least one transceiver; at least one processor; as well as at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations comprising: monitoring a common downlink signal of the first cell in a first mode on a first cell with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and Based on the transition from the first mode to the second mode, the common downlink signal of the first cell is monitored on the second cell for a first time period.

10. A processing device in a wireless communication system, the processing device comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations comprising: monitoring a common downlink signal of the first cell in a first mode on a first cell with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and Based on the transition from the first mode to the second mode, the common downlink signal of the first cell is monitored on the second cell for a first time period.

11. A computer-readable storage medium configured to store at least one program code comprising instructions that, when executed, cause at least one processor to perform operations comprising: monitoring a common downlink signal of the first cell in a first mode on a first cell with a first periodicity; receiving a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and Based on the transition from the first mode to the second mode, the common downlink signal of the first cell is monitored on the second cell for a first time period.

12. A method for sending a downlink signal by a base station BS to a user equipment UE in a wireless communication system, the method comprising the following steps: Sending a common downlink signal of the first cell in a first mode on a first cell with a first periodicity; sending a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and Based on the transition from the first mode to the second mode, the common downlink signal of the first cell is transmitted on the second cell within a first time period.

13. A base station BS configured to send a downlink signal to a user equipment UE in a wireless communication system, the BS comprising: at least one transceiver; at least one processor; as well as at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations comprising: Sending a common downlink signal of the first cell in a first mode on a first cell with a first periodicity; sending a configuration related to a second mode, wherein the configuration related to the second mode includes information about a time period for the second mode and cell information about a second cell associated with the first cell; and Based on the transition from the first mode to the second mode, the common downlink signal of the first cell is transmitted on the second cell within a first time period.

14. The BS according to claim 13, wherein: The common downlink signal of the first cell is system information, a paging message or a synchronization signal block SSB of the first cell, and The SSB is composed of the primary synchronization signal PSS of the first cell, the secondary synchronization signal SSS of the first cell and the physical broadcast channel PBCH of the first cell.

15. The BS according to claim 13, wherein: The operations include sending a group common downlink control information (DCI) format related to transitioning to the second mode.

16. The BS according to claim 15, wherein: The information about the time period for the second mode includes configuration for a plurality of time periods, and The group common DCI format includes information about a first time period among the multiple time periods.

17. The BS according to claim 15, wherein: The operations also include receiving an acknowledgement ACK or a negative ACK NACK for transitioning to the second mode in response to the transmission of the set common DCI format.

18. The BS according to claim 13, wherein: The operations include: sending a configuration related to a third mode related to the first cell, wherein the configuration related to the third mode includes information about a time period for the third mode; Based on the transition from the first mode to the third mode, transmitting a physical downlink control channel PDCCH of a system information block 1 SIB1 for the first cell on the first cell within a second time period; and Based on receiving a SIB1 request on a random access channel RACH resource related to the PDCCH for the SIB1, a physical downlink shared channel PDSCH carrying the SIB1 is sent.

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