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WO2024215047A2 - Procédé et dispositif d'économie d'énergie dans système de communication sans fil - Google Patents

Procédé et dispositif d'économie d'énergie dans système de communication sans fil Download PDF

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Publication number
WO2024215047A2
WO2024215047A2 PCT/KR2024/004697 KR2024004697W WO2024215047A2 WO 2024215047 A2 WO2024215047 A2 WO 2024215047A2 KR 2024004697 W KR2024004697 W KR 2024004697W WO 2024215047 A2 WO2024215047 A2 WO 2024215047A2
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WIPO (PCT)
Prior art keywords
wus
cell
base station
terminal
information
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English (en)
Korean (ko)
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WO2024215047A3 (fr
Inventor
이준영
김영범
박성진
이재원
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Samsung Electronics Co Ltd
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Samsung Electronics Co Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0203—Power saving arrangements in the radio access network or backbone network of wireless communication networks
    • H04W52/0206—Power saving arrangements in the radio access network or backbone network of wireless communication networks in access points, e.g. base stations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
    • H04W48/14—Access restriction or access information delivery, e.g. discovery data delivery using user query or user detection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/001—Synchronization between nodes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/04—Wireless resource allocation
    • H04W72/044—Wireless resource allocation based on the type of the allocated resource
    • H04W72/0453—Resources in frequency domain, e.g. a carrier in FDMA
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/21—Control channels or signalling for resource management in the uplink direction of a wireless link, i.e. towards the network
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present disclosure relates to a method and apparatus for energy saving in a wireless communication system.
  • 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band, such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave), such as 28GHz and 39GHz ('Above 6GHz').
  • mmWave millimeter wave
  • mmWave millimeter wave
  • 28GHz and 39GHz 'Above 6GHz'
  • 6G mobile communication technology which is called the system after 5G communication (Beyond 5G)
  • implementation in the terahertz band for example, the 3 terahertz (3THz) band at 95GHz
  • 3THz the 3 terahertz
  • the technologies included beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2 Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.
  • LDPC Low Density Parity Check
  • V2X Vehicle-to-Everything
  • NR-U New Radio Unlicensed
  • UE Power Saving NR terminal low power consumption technology
  • NTN Non-Terrestrial Network
  • Standardization of wireless interface architecture/protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR to simplify random access procedures is also in progress, and standardization of system architecture/services for 5G baseline architecture (e.g. Service based Architecture, Service based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal is also in progress.
  • 5G baseline architecture e.g. Service based Architecture, Service based Interface
  • NFV Network Functions Virtualization
  • SDN Software-Defined Networking
  • MEC Mobile Edge Computing
  • Various embodiments of the present disclosure provide a new cell definition and a method for on-demand cell activation through a wake-up signal (WUS) transmitted by a terminal for reducing energy consumption of a base station in a wireless communication system.
  • WUS wake-up signal
  • a method for reducing energy consumption of a base station by a base station in a wireless communication system may include an operation in which the base station activates a cell for access or synchronization (e.g., an Access/Sync cell) and deactivates an on-demand cell for traffic (or packet) processing (e.g., a Data cell), and an operation in which the base station sets configuration information for a WUS, etc. to activate the on-demand cell through upper layer signaling and L1 signaling to terminals that have performed initial access (or, RACH procedure) through the Access/Sync cell, and a method in which the terminal activates the on-demand cell based on the configuration.
  • a cell for access or synchronization e.g., an Access/Sync cell
  • deactivates an on-demand cell for traffic (or packet) processing e.g., a Data cell
  • the base station sets configuration information for a WUS, etc. to activate the on-demand cell through upper layer signaling and L1 signaling to terminals that have performed initial access (or
  • a method for reducing energy consumption of a base station by a terminal in a wireless communication system may include an operation in which the terminal performs an initial access (or RACH procedure) to an Access/Sync cell, an operation in which the terminal receives configuration information of an on-demand cell for processing traffic (or packets) from the base station through upper layer signaling, and an operation in which a WUS for activating the on-demand cell is transmitted based on the received information.
  • a method performed by a terminal of a communication system comprises: a step of performing an initial connection procedure with a first base station corresponding to a first cell; a step of receiving wake up signal (WUS) configuration information from the first base station; a step of transmitting a WUS to a second base station corresponding to a second cell based on the WUS configuration information; and a step of monitoring a response signal (acknowledgement) corresponding to the WUS during a WUS response window, wherein the WUS configuration information includes at least one of carrier frequency information of the second cell, WUS transmission occasion information, WUS format information, and WUS response window configuration information.
  • WUS configuration information includes at least one of carrier frequency information of the second cell, WUS transmission occasion information, WUS format information, and WUS response window configuration information.
  • a method performed by a first base station corresponding to a first cell of a communication system comprising: a step of performing an initial connection procedure with a terminal; and a step of transmitting wake up signal (WUS) setting information to the terminal, wherein the first base station corresponding to the first cell is connected to a second base station corresponding to a second cell, and a WUS according to the WUS setting information is transmitted from the terminal to the second base station, and the WUS setting information includes at least one of carrier frequency information of the second cell, WUS transmission occasion information, WUS format information, and WUS response window setting information.
  • WUS wake up signal
  • the method comprises the steps of: receiving a wake up signal (WUS) from a terminal; transmitting an acknowledgement signal for the WUS to the terminal during a WUS response window; and performing an access procedure for the terminal and the second cell, wherein WUS related information is transmitted from the second base station to a first base station corresponding to the first cell, and the WUS related information includes at least one of carrier frequency information of the second cell, WUS transmission occasion information, WUS format information, and WUS response window setting information.
  • WUS wake up signal
  • a transceiver in a terminal of a communication system, a transceiver; and a control unit connected to the transceiver and including one or more processors, wherein the control unit is configured to: perform an initial access procedure with a first base station corresponding to a first cell, receive wake up signal (WUS) configuration information from the first base station, transmit a WUS to a second base station corresponding to a second cell based on the WUS configuration information, and monitor a response signal (acknowledgement) corresponding to the WUS during a WUS response window, wherein the WUS configuration information includes at least one of carrier frequency information of the second cell, WUS transmission occasion information, WUS format information, and WUS response window configuration information.
  • WUS configuration information includes at least one of carrier frequency information of the second cell, WUS transmission occasion information, WUS format information, and WUS response window configuration information.
  • a transceiver configured to perform an initial connection procedure with a terminal and transmit wake up signal (WUS) configuration information to the terminal, and the first base station corresponding to the first cell is connected to a second base station corresponding to a second cell, and a WUS according to the WUS configuration information is transmitted from the terminal to the second base station, and the WUS configuration information includes at least one of carrier frequency information, WUS transmission occasion information, WUS format information, and WUS response window configuration information of the second cell, and the first cell corresponds to a cell type for connection and synchronization, and the second cell corresponds to a cell type for data transmission and reception.
  • WUS wake up signal
  • a transceiver in a second base station corresponding to a second cell of a communication system, a transceiver; and a control unit connected to the transceiver and including one or more processors, wherein the control unit is configured to: receive a wake up signal (WUS) from a terminal, transmit an acknowledgement signal for the WUS to the terminal during a WUS acknowledgement window; and perform an access procedure for the terminal and the second cell, wherein WUS related information is transmitted from the second base station to a first base station corresponding to the first cell, and the WUS related information includes at least one of carrier frequency information, WUS transmission occasion information, WUS format information, and WUS acknowledgement window setting information of the second cell, and wherein the first cell corresponds to a cell type for access and synchronization, and the second cell corresponds to a cell type for data transmission and reception.
  • WUS wake up signal
  • the control unit is configured to: receive a wake up signal (WUS) from a terminal, transmit an acknowledgement signal for the WUS to the
  • the base station can reduce the overhead of always having to periodically activate cells for common channels and signal transmission, thereby managing and saving the energy of the base station more efficiently.
  • Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource domain in a wireless communication system.
  • Figure 2 is a diagram illustrating a slot structure considered in a wireless communication system.
  • FIG. 3 is a diagram showing an example of a time domain mapping structure of a synchronization signal and a beam sweeping operation.
  • FIG. 4 is a diagram illustrating a synchronization signal block considered in a wireless communication system.
  • FIG. 5 is a diagram illustrating an example of various transmissions of a synchronization signal block in a frequency band below 6 GHz considered in a communication system to which the present disclosure is applied.
  • FIG. 6 is a diagram illustrating an example of transmission of a synchronization signal block in a frequency band of 6 GHz or higher considered in a wireless communication system to which the present disclosure is applied.
  • FIG. 7 is a diagram illustrating an example of transmission of a synchronization signal block according to a subcarrier interval within 5 ms in a wireless communication system to which the present disclosure is applied.
  • Figure 8 is a diagram illustrating an example of DMRS patterns (type 1 and type 2) used for communication between a base station and a terminal in a 5G system.
  • FIG. 9 is a diagram illustrating an example of channel estimation using DMRS received on one PUSCH in a time band of a 5G system to which the present disclosure is applied.
  • FIG. 10 is a diagram illustrating an example of a method for resetting SSB transmission through dynamic signaling according to an embodiment.
  • FIG. 11 is a diagram illustrating an example of a method for resetting BWP and BW through dynamic signaling according to an embodiment.
  • FIG. 12 is a diagram illustrating an example of a method for resetting DRX through dynamic signaling according to an embodiment.
  • FIG. 13 is a diagram illustrating an example of a DTx method for base station energy saving.
  • Figure 14 is a diagram for explaining an example of the operation of a base station according to gNB WUS.
  • FIG. 15 is a diagram illustrating an example of a spatial domain (SD) adaptation method of a base station for energy saving according to an embodiment.
  • SD spatial domain
  • FIG. 16 is a diagram illustrating an example of a concept of cells having different functions for energy saving according to an embodiment.
  • FIG. 17 is a diagram illustrating an example of an on-demand cell selection method for energy saving of a base station according to an embodiment.
  • FIG. 18a is a diagram illustrating an example of a procedure for on-demand cell selection for energy saving of a base station according to an embodiment of the present disclosure.
  • FIG. 18b is a diagram illustrating an example of a procedure for on-demand cell selection for energy saving of a base station according to an embodiment of the present disclosure.
  • FIG. 19a is a diagram illustrating an example of a WUS transmission method for activating data cells for energy saving of a base station according to an embodiment.
  • FIG. 19b is a diagram illustrating another example of a WUS transmission method for activating data cells for energy saving of a base station according to an embodiment.
  • FIG. 20 is a flowchart illustrating an example of an operation of a terminal that applies a cell selection method for energy saving of a base station in a 5G or 6G system to which the present disclosure is applied.
  • FIG. 21A is a flowchart illustrating an example of a base station operation serving a cell of cell type 1 applying a cell selection method for energy saving of a base station in a 5G or 6G system to which the present disclosure is applied.
  • FIG. 21b is a flowchart illustrating an example of a base station operation serving a cell of cell type 2 for energy saving of the base station in a 5G or 6G system to which the present disclosure is applied.
  • FIG. 22 is a block diagram of a terminal according to one embodiment of the present disclosure.
  • FIG. 23 is a block diagram of a base station according to one embodiment of the present disclosure.
  • A/B/C may be understood as at least one of A, B, and C.
  • the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network.
  • the terminal may include a UE (user equipment), an MS (mobile station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function.
  • the downlink (DL) refers to a wireless transmission path of a signal that a base station transmits to a terminal
  • the uplink (UL) refers to a wireless transmission path of a signal that a terminal transmits to a base station.
  • an LTE or LTE-A system may be described as an example below, embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel type.
  • the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services.
  • the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure, as judged by a person having skilled technical knowledge.
  • each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions.
  • These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s).
  • These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement the function in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured article including an instruction means for performing the functions described in the flow diagram block(s).
  • the computer program instructions may be installed on a computer or other programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable data processing apparatus to produce a computer-executable process, so that the instructions executing the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).
  • each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.
  • the term ' ⁇ part' used in this disclosure means a software or hardware component such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), and the ' ⁇ part' performs certain roles.
  • the ' ⁇ part' is not limited to software or hardware.
  • the ' ⁇ part' may be configured to be on an addressable storage medium and may be configured to play one or more processors.
  • the ' ⁇ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables.
  • components and ' ⁇ parts' may be combined into a smaller number of components and ' ⁇ parts' or further separated into additional components and ' ⁇ parts'.
  • the components and ' ⁇ parts' may be implemented to play one or more CPUs within the device or secure multimedia card.
  • the ' ⁇ part' may include one or more processors.
  • Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 3GPP's HSPA (high speed packet access), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (high rate packet data), UMB (ultra mobile broadband), and IEEE's 802.17e communication standards.
  • 3GPP's HSPA high speed packet access
  • LTE long term evolution or E-UTRA (evolved universal terrestrial radio access)
  • LTE-A LTE-Advanced
  • LTE-Pro LTE-Pro
  • 3GPP2's HRPD high rate packet data
  • UMB ultra mobile broadband
  • IEEE's 802.17e communication standards such as 3GPP's HSPA (high speed packet access), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)
  • LTE-A long term evolution
  • the downlink (DL) adopts the OFDM (orthogonal frequency division multiplexing) method
  • the uplink (UL) adopts the SC-FDMA (single carrier frequency division multiple access) method.
  • the uplink refers to a wireless link in which a terminal transmits data or a control signal to a base station
  • the downlink refers to a wireless link in which a base station transmits data or a control signal to a terminal (UE).
  • the aforementioned multiple access method typically allocates and operates time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so that orthogonality is established, thereby distinguishing the data or control information of each user.
  • the 5G communication system which is a communication system after LTE, must support services that simultaneously satisfy various requirements so that it can freely reflect the diverse needs of users and service providers.
  • Services considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), or ultra reliability low latency communication (URLLC).
  • eMBB enhanced mobile broadband
  • mMTC massive machine type communication
  • URLLC ultra reliability low latency communication
  • eMBB aims to provide a data transmission rate that is higher than that supported by existing LTE, LTE-A or LTE-Pro.
  • eMBB should be able to provide a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station.
  • the 5G communication system should provide an increased user perceived data rate while providing the peak data rate.
  • improvements in various transmission/reception technologies including further improved multi-input multi-output (MIMO) transmission technology, may be required.
  • MIMO multi-input multi-output
  • a 5G communication system can satisfy the data transmission rate required by the 5G communication system by using a wider frequency bandwidth than 20 MHz in a frequency band of 3 to 6 GHz or higher than 6 GHz.
  • mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems.
  • IoT Internet of Things
  • mMTC requires support for mass terminal connection, improved terminal coverage, improved battery life, and reduced terminal cost in order to efficiently provide the Internet of Things. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it must be able to support a large number of terminals (e.g., 1,000,000 terminals/ km2 ) in a cell.
  • terminals supporting mMTC are likely to be located in shadow areas that cells do not cover, such as basements of buildings, due to the nature of the service, and therefore require wider coverage than other services provided by 5G communication systems.
  • Terminals supporting mMTC must be composed of low-cost terminals, and since it is difficult to frequently replace the terminal batteries, they require very long battery life times, such as 10 to 16 years.
  • URLLC is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services used for remote control of robots or machinery, industrial automation, unmanaged aerial vehicles, remote health care, or emergency alert can be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and at the same time, satisfy the requirement of a packet error rate of less than 10 -5 . Therefore, for a service supporting URLLC, the 5G system must provide a smaller transmit time interval (TTI) than other services, and at the same time, allocate wide resources in the frequency band to secure the reliability of the communication link.
  • TTI transmit time interval
  • the three services of the 5G communication system (hereinafter, interchangeable with the 5G system), namely, eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system.
  • Different transmission/reception techniques and transmission/reception parameters can be used between services to satisfy different requirements of each service.
  • FIG. 1 is a diagram illustrating the basic structure of a time-frequency domain, which is a wireless resource domain, in a wireless communication system to which the present disclosure is applied.
  • the horizontal axis represents the time domain
  • the vertical axis represents the frequency domain.
  • the basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as one OFDM (orthogonal frequency division multiplexing) symbol (or DFT-s-OFDM (discrete Fourier transform spread OFDM) symbol) (102) in the time axis and one subcarrier (subcarrier, 103) in the frequency axis.
  • OFDM orthogonal frequency division multiplexing
  • DFT-s-OFDM discrete Fourier transform spread OFDM
  • 103 subcarrier
  • RB resource block
  • consecutive REs can form one resource block (RB, 104).
  • the number of symbols per subframe in the time domain is indicated.
  • a set of consecutive OFDM symbols can constitute one subframe (subframe, 110).
  • FIG. 2 is a diagram illustrating a slot structure considered in a wireless communication system to which the present disclosure is applied.
  • FIG. 2 illustrates an example of a slot structure including a frame (200), a subframe (201), and a slot (202 or 203).
  • One frame (200) can be defined as 10 ms.
  • One subframe (201) can be defined as 1 ms, and therefore one frame (200) can be composed of a total of 10 subframes (201).
  • One subframe (201) may be composed of one or more slots (202 or 203), and the number of slots (202 or 203) per one subframe (201) may vary depending on ⁇ (204 or 205), which is a setting value for the subcarrier space (SCS).
  • SCS subcarrier space
  • a synchronization signal block (SSB, which may be used interchangeably with an SS block or an SS/PBCH block) may be transmitted for initial connection of a terminal, and the synchronization signal block may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH).
  • PSS primary synchronization signal
  • SSS secondary synchronization signal
  • PBCH physical broadcast channel
  • the terminal can first obtain downlink time and frequency domain synchronization from a synchronization signal through a cell search and obtain a cell ID.
  • the synchronization signal may include a PSS and an SSS.
  • the terminal can obtain transmission and reception related system information such as a system bandwidth or related control information and basic parameter values by receiving a PBCH transmitting a master information block (MIB) from a base station. Based on this information, the terminal can perform decoding on a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) to obtain a system information block (SIB).
  • PDCH physical downlink control channel
  • PDSCH physical downlink shared channel
  • the terminal can exchange identification related information between the base station and the terminal through a random access stage and go through registration and authentication stages to initially access the network.
  • the terminal can obtain cell common transmission and reception related control information by receiving system information (or SIB) transmitted by the base station.
  • SIB system information
  • the above cell common transmission and reception related control information may include random access related control information, paging related control information, common control information for various physical channels, etc.
  • a synchronization signal is a signal that serves as a reference for cell search, and a subcarrier spacing can be applied to suit channel environments such as phase noise, etc., for each frequency band.
  • a subcarrier spacing can be applied differently depending on the service type in order to support various services as described above.
  • FIG. 3 is a diagram showing an example of a time domain mapping structure of a synchronization signal and a beam sweeping operation.
  • - PSS A signal that serves as a reference for DL time/frequency synchronization and provides some cell ID information.
  • - SSS It serves as a reference for DL time/frequency synchronization and provides some remaining information such as cell ID. Additionally, it can serve as a reference signal for demodulation of PBCH.
  • MIB which is essential system information required for transmission and reception of data channels and control channels of the terminal.
  • the essential system information may include information such as search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, and SFN (system frame number), which is a frame unit index that serves as a timing reference.
  • An SS/PBCH block consists of N OFDM symbols and is composed of a combination of PSS, SSS, PBCH, etc.
  • an SS/PBCH block is the minimum unit to which beam sweeping is applied.
  • N can be 4.
  • a base station can transmit up to L SS/PBCH blocks, and the L SS/PBCH blocks are mapped within a half frame (0.5 ms).
  • the L SS/PBCH blocks are periodically repeated in units of a predetermined period P. The period P can be notified to a terminal by a signaling from the base station. If there is no separate signaling for the period P, the terminal applies a pre-agreed default value.
  • FIG. 3 shows an example in which beam sweeping is applied to SS/PBCH block units over time.
  • terminal 1 (305) receives an SS/PBCH block using a beam radiated in the direction of #d0 (303) by beamforming applied to SS/PBCH block #0 at time t1 (301).
  • terminal 2 (306) receives an SS/PBCH block using a beam radiated in the direction of #d4 (304) by beamforming applied to SS/PBCH block #4 at time t2 (302).
  • the terminal can obtain an optimal synchronization signal through a beam radiated from the base station in the direction where the terminal is located.
  • terminal 1 (305) may have difficulty in obtaining time/frequency synchronization and essential system information from an SS/PBCH block through a beam radiated in the direction of #d4, which is far from the location of terminal 1.
  • the terminal may also receive the SS/PBCH block to determine whether the radio link quality of the current cell is maintained at a certain level or higher.
  • the terminal may receive the SS/PBCH block of the adjacent cell to determine the radio link quality of the adjacent cell and obtain time/frequency synchronization of the adjacent cell.
  • the synchronization signal is a signal that serves as a reference for cell search, and can be transmitted by applying a subcarrier interval suitable for the channel environment (e.g., phase noise) for each frequency band.
  • the 5G base station can transmit multiple synchronization signal blocks according to the number of analog beams to be operated. For example, PSS and SSS can be mapped and transmitted across 12 RBs, and PBCH can be mapped and transmitted across 24 RBs. The structure in which the synchronization signal and PBCH are transmitted in the 5G communication system is described below.
  • FIG. 4 is a diagram illustrating a synchronization signal block considered in a wireless communication system to which the present disclosure is applied.
  • a synchronization signal block may include a PSS (401), an SSS (403), and a PBCH (402).
  • the synchronization signal block (400) can be mapped to four OFDM symbols (404) in the time axis.
  • the PSS (401) and the SSS (403) can be transmitted in 12 RBs (405) in the frequency axis and in the first and third OFDM symbols in the time axis, respectively.
  • a total of 1008 different cell IDs can be defined.
  • the PSS (401) can have three different values
  • the SSS (403) can have 336 different values.
  • SSS(403) can have a value between 0 and 335.
  • PSS (401) can have a value between 0 and 2.
  • the terminal class Cell ID is a combination of The value can be estimated.
  • PBCH (402) can be transmitted in resources including 6 RBs (407, 408) on both sides, excluding 12 RBs (405) in the middle, while SSS (403) is transmitted in 24 RBs (406) in the frequency axis and in the 2nd to 4th OFDM symbols of an SS block in the time axis.
  • PBCH (402) can include a PBCH payload and a PBCH DMRS (demodulation reference signal), and various system information called MIB can be transmitted in the PBCH payload.
  • MIB can include information as shown in Table 2 below.
  • MIB SEQUENCE ⁇ systemFrameNumber BIT STRING (SIZE (6)); subCarrierSpacingCommon ENUMERATED ⁇ scs15or60, scs30or120 ⁇ , ssb-SubcarrierOffset INTEGER (0..15); dmrs-TypeA-Position ENUMERATED ⁇ pos2, pos3 ⁇ , pdcch-ConfigSIB1 PDCCH-ConfigSIB1, cellBarred ENUMERATED ⁇ barred, notBarred ⁇ , intraFreqReselection ENUMERATED ⁇ allowed, notAllowed ⁇ , spare BIT STRING (SIZE (1)) ⁇
  • the frequency domain offset of the synchronization signal block can be indicated through the 4-bit ssb-SubcarrierOffset in the MIB.
  • the index of the synchronization signal block including the PBCH can be indirectly obtained through decoding of the PBCH DMRS and PBCH.
  • 3 bits obtained through decoding of PBCH DMRS indicate a synchronization signal block index
  • a total of 6 bits, including 3 bits obtained through decoding of PBCH DMRS and 3 bits obtained through PBCH decoding included in the PBCH payload can indicate a synchronization signal block index including the PBCH.
  • the subcarrier spacing of the common downlink control channel can be indicated through 1 bit (subCarrierSpacingCommon) in the MIB, and time-frequency resource configuration information of CORESET (control resource set) and search space (SS) can be indicated through 8 bits (pdcch-ConfigSIB1).
  • - SFN 6 bits (systemFrameNumber) in the MIB can be used to indicate part of the SFN.
  • the 4 least significant bits (LSB) of the SFN are included in the PBCH payload, so that the terminal can obtain them indirectly through PBCH decoding.
  • the synchronization signal block index described above and 1 bit included in the PBCH payload are obtained through PBCH decoding, allowing the terminal to indirectly determine whether the synchronization signal block was transmitted in the first or second half frame of the radio frame.
  • the transmission bandwidths (12 RB (405)) of the PSS (401) and SSS (403) and the transmission bandwidth (24 RB (406)) of the PBCH (402) are different from each other, in the first OFDM symbol where the PSS (401) is transmitted within the transmission bandwidth of the PBCH (402), 6 RBs (407, 408) on both sides exist except for the 12 RBs in the middle where the PSS (401) is transmitted, and the above areas can be used to transmit other signals or can be empty.
  • Synchronization signal blocks can be transmitted using the same analog beam.
  • PSS (401), SSS (403), and PBCH (402) can all be transmitted using the same beam. Since analog beams have a characteristic that they cannot be applied differently in the frequency axis, the same analog beam can be applied to all frequency axis RBs within a specific OFDM symbol to which a specific analog beam is applied. For example, four OFDM symbols in which PSS (401), SSS (403), and PBCH (402) are transmitted can all be transmitted using the same analog beam.
  • FIG. 5 is a diagram illustrating an example of various transmissions of a synchronization signal block in a frequency band below 6 GHz considered in a communication system to which the present disclosure is applied.
  • a 15 kHz subcarrier spacing (SCS, 520) and a 30 kHz subcarrier spacing (530, 440) may be used for transmission of a synchronization signal block in a frequency band below 6 GHz.
  • the 15 kHz subcarrier spacing (520) there may be one transmission case (e.g., case #1 (501)) for a synchronization signal block
  • the 30 kHz subcarrier spacing (530, 540) there may be two transmission cases (e.g., case #2 (402) and case #3 (503)) for a synchronization signal block.
  • synchronization signal block #0 (507) and synchronization signal block #1 (508) are illustrated.
  • synchronization signal block #0 (507) can be mapped to 4 consecutive symbols from the 3rd OFDM symbol
  • synchronization signal block #1 (508) can be mapped to 4 consecutive symbols from the 9th OFDM symbol.
  • Different analog beams may be applied to the synchronization signal block #0 (507) and the synchronization signal block #1 (508).
  • the same beam may be applied to all 3rd to 6th OFDM symbols to which the synchronization signal block #0 (507) is mapped, and the same beam may be applied to all 9th to 12th OFDM symbols to which the synchronization signal block #1 (508) is mapped.
  • the analog beam may be freely determined at the discretion of the base station to determine which beam to use.
  • Synchronization signal block #0 (509) and synchronization signal block #1 (510) can be mapped from the 5th OFDM symbol and the 9th OFDM symbol of the first slot, respectively, and synchronization signal block #2 (511) and synchronization signal block #3 (512) can be mapped from the 3rd OFDM symbol and the 7th OFDM symbol of the second slot, respectively.
  • Different analog beams may be applied to the synchronization signal block #0 (509), synchronization signal block #1 (510), synchronization signal block #2 (511), and synchronization signal block #3 (512), respectively.
  • the same analog beam may be applied to the 5th to 8th OFDM symbols of the first slot in which synchronization signal block #0 (509) is transmitted, the 9th to 12th OFDM symbols of the first slot in which synchronization signal block #1 (510) is transmitted, the 3rd to 6th symbols of the second slot in which synchronization signal block #2 (511) is transmitted, and the 7th to 10th symbols of the second slot in which synchronization signal block #3 (512) is transmitted, respectively.
  • the analog beam may be freely determined at the discretion of the base station as to which beam to use.
  • synchronization signal block #0 513
  • synchronization signal block #1 514
  • synchronization signal block #2 515
  • synchronization signal block #3 516
  • Synchronization signal block #0 (513) and synchronization signal block #1 (514) can be mapped from the 3rd OFDM symbol and the 9th OFDM symbol of the first slot, respectively, and synchronization signal block #2 (515) and synchronization signal block #3 (516) can be mapped from the 3rd OFDM symbol and the 9th OFDM symbol of the second slot, respectively.
  • Different analog beams may be used for the above synchronization signal block #0 (513), synchronization signal block #1 (514), synchronization signal block #2 (515), and synchronization signal block #3 (516), respectively.
  • the same analog beam may be used in all four OFDM symbols in which each synchronization signal block is transmitted, and which beam to use in OFDM symbols to which the synchronization signal block is not mapped may be freely determined at the discretion of the base station.
  • FIG. 6 is a diagram illustrating an example of transmission of a synchronization signal block in a frequency band of 6 GHz or higher considered in a wireless communication system to which the present disclosure is applied.
  • a subcarrier spacing of 120 kHz (630) as in the example of Case #4 (610) and a subcarrier spacing of 240 kHz (640) as in the example of Case #5 (620) can be used for transmission of synchronization signal blocks.
  • synchronization signal block #0 (603), synchronization signal block #1 (604), synchronization signal block #2 (605), and synchronization signal block #3 (606) are illustrated as being transmitted within 0.25 ms (i.e., two slots).
  • Synchronization signal block #0 (603) and synchronization signal block #1 (604) can be mapped to four consecutive symbols from the 5th OFDM symbol of the first slot and to four consecutive symbols from the 9th OFDM symbol, respectively, and synchronization signal block #2 (605) and synchronization signal block #3 (606) can be mapped to four consecutive symbols from the 3rd OFDM symbol of the second slot and to four consecutive symbols from the 7th OFDM symbol, respectively.
  • different analog beams may be used for each of synchronization signal block #0 (603), synchronization signal block #1 (604), synchronization signal block #2 (605), and synchronization signal block #3 (606).
  • the same analog beam may be used in all four OFDM symbols in which each synchronization signal block is transmitted, and which beam to use in OFDM symbols to which the synchronization signal block is not mapped may be freely determined at the discretion of the base station.
  • synchronization signal block #0 (607), synchronization signal block #1 (608), synchronization signal block #2 (609), synchronization signal block #3 (610), synchronization signal block #4 (611), synchronization signal block #5 (612), synchronization signal block #6 (613), and synchronization signal block #7 (614) are illustrated as being transmitted within 0.25 ms (i.e. 4 slots).
  • Synchronization signal block #0 (607) and synchronization signal block #1 (608) can be mapped to 4 consecutive symbols from the 9th OFDM symbol of the first slot, and to 4 consecutive symbols from the 13th OFDM symbol, respectively, and synchronization signal block #2 (609) and synchronization signal block #3 (610) can be mapped to 4 consecutive symbols from the 3rd OFDM symbol of the second slot, and to 4 consecutive symbols from the 7th OFDM symbol, respectively, and synchronization signal block #4 (611), synchronization signal block #5 (612), and synchronization signal block #6 (613) can be mapped to 4 consecutive symbols from the 5th OFDM symbol of the third slot, and to 4 consecutive symbols from the 9th OFDM symbol, and to 4 consecutive symbols from the 13th OFDM symbol, respectively, and synchronization signal block #7 (614) can be mapped to 4 consecutive symbols from the 4th OFDM symbol of the It can be mapped to four consecutive symbols starting from the third OFDM symbol.
  • different analog beams may be used for synchronization signal block #0 (607), synchronization signal block #1 (608), synchronization signal block #2 (609), synchronization signal block #3 (610), synchronization signal block #4 (611), synchronization signal block #5 (612), synchronization signal block #6 (613), and synchronization signal block #7 (614), respectively.
  • the same analog beam may be used in all four OFDM symbols in which each synchronization signal block is transmitted, and in OFDM symbols to which the synchronization signal block is not mapped, which beam to be used may be freely determined at the discretion of the base station.
  • FIG. 7 is a diagram illustrating an example of transmission of a synchronization signal block according to a subcarrier interval within 5 ms in a wireless communication system to which the present disclosure is applied.
  • a synchronization signal block may be transmitted periodically in units of, for example, a time interval (710) of 5 ms (corresponding to 5 subframes or half frames).
  • up to 4 synchronization signal blocks can be transmitted within 5 ms (710) time.
  • up to 8 synchronization signal blocks can be transmitted.
  • up to 64 synchronization signal blocks can be transmitted.
  • subcarrier spacing of 15 kHz and 30 kHz can be used in the frequency below 6 GHz.
  • synchronization signal blocks can be mapped to the first and second slots in a frequency band of 3 GHz or less, so that up to 4 (721) can be transmitted, and in the frequency band exceeding 3 GHz and below 6 GHz, synchronization signal blocks can be mapped to the first, second, third, and fourth slots, so that up to 8 (722) can be transmitted.
  • synchronization signal blocks can be mapped starting from the first slot in a frequency band below 3 GHz, so that up to 4 (731, 741) can be transmitted, and in a frequency band exceeding 3 GHz and below 6 GHz, synchronization signal blocks can be mapped starting from the first and third slots, so that up to 8 (732, 742) can be transmitted.
  • Subcarrier spacing of 120 kHz and 240 kHz can be used in frequencies exceeding 6 GHz.
  • synchronization signal blocks can be mapped starting from the 1st, 3rd, 5th, 7th, 11th, 13th, 15th, 17th, 21st, 23rd, 25th, 27th, 31st, 33rd, 35th, and 37th slots in the frequency band exceeding 6 GHz, so that up to 64 (751) can be transmitted.
  • Fig. 7 in case #5 (620) of Fig.
  • synchronization signal blocks in a frequency band exceeding 6 GHz can be mapped starting from the 1st, 5th, 9th, 13th, 21st, 25th, 29th, and 33rd slots, so that up to 64 (761) can be transmitted.
  • the terminal can obtain SIB after performing decoding of PDCCH and PDSCH based on system information included in the received MIB.
  • SIB can include at least one of uplink cell bandwidth related information, random access parameters, paging parameters, or parameters related to uplink power control.
  • a terminal can form a wireless link with a network through a random access procedure based on synchronization with the network and system information acquired during a cell search process of a cell.
  • Random access can use a contention-based or non-contention-based (contention-free) method.
  • a contention-based random access method can be used, for example, for the purpose of moving from an RRC_IDLE (RRC idle) state to an RRC_CONNECTED (RRC connected) state.
  • Non-contention-based random access can be used to re-establish uplink synchronization when downlink data arrives, in the case of a handover, or in the case of position measurement.
  • Table 3 shows examples of conditions (events) that trigger a random access procedure in a 5G system.
  • the terminal receives MeasObjectNR of MeasObjectToAddModList as a setting for SSB-based intra/inter-frequency measurements and CSI-RS-based intra/inter-frequency measurements through upper layer signaling.
  • MeasObjectNR can be configured as shown in Table 4 below.
  • MeasObjectNR SEQUENCE ⁇ ssbFrequency ARFCN-ValueNR OPTIONAL, -- Cond SSBorAssociatedSSB ssbSubcarrierSpacing SubcarrierSpacing OPTIONAL, -- Cond SSBorAssociatedSSB smtc1 SSB-MTC OPTIONAL, -- Cond SSBorAssociatedSSB smtc2 SSB-MTC2 OPTIONAL, -- Cond IntraFreqConnected refFreqCSI-RS ARFCN-ValueNR OPTIONAL, -- Cond CSI-RS referenceSignalConfig ReferenceSignalConfig; absThreshSS-BlocksConsolidation ThresholdNR OPTIONAL, -- Need R absThreshCSI-RS-Consolidation ThresholdNR OPTIONAL, -- Need R nrofSS-BlocksToAverage INTEGER (2..maxNrofSS-BlocksToAverage) OPTIONAL,
  • FR frequency range 1 can only apply 15 kHz or 30 kHz, and FR2 can only apply 120 kHz or 240 kHz.
  • - smtc1 Indicates SMTC (SS/PBCH block measurement timing configuration), and can set the primary measurement timing configuration and the timing offset and duration for SSB.
  • SIB2 for intra-frequency, inter-frequency and inter-RAT (radio access technology) cell re-selection, or reconfigurationWithSync for NR PSCell (primary secondary cell) change and NR PCell (primary cell) change
  • SMTC can be configured to the UE through SCellConfig for NR SCell addition.
  • the terminal can set the first SMTC according to periodictiyAndOffset (providing periodicity and offset) through smtc1 set through upper layer signaling for SSB measurement.
  • the first subframe of each SMTC occasion can start in the subframe of SFN and SpCell satisfying the conditions of Table 5 below.
  • the terminal can set additional SMTC according to the set smtc2 periodicity and the offset and interval of smtc1 for the cells indicated by the pci-List value of smtc2 in the same MeasObjectNR.
  • the terminal can be set to smtc and measure SSB through smtc2-LP (with long periodicity) and smtc3list for IAB-MT (integrated access and backhaul - mobile termination) for the same frequency (e.g., frequency for intra-frequency cell reselection) or different frequencies (e.g., frequencies for inter-frequency cell reselection).
  • the terminal may not consider SSB transmitted in subframes other than SMTC occasions for SSB-based RRM measurement at the set ssbFrequency.
  • the base station can use various multi-TRP (transmit/receive point) operation schemes depending on the serving cell configuration and the PCI configuration. Among these, when two TRPs located at a physically separate distance have different PCIs, there may be two ways to operate the two TRPs.
  • Two TRPs with different PCIs can be operated with two serving cell configurations.
  • the base station can configure channels and signals transmitted from different TRPs into different serving cell configurations through [Operation Method 1]. That is, each TRP has an independent serving cell configuration, and the frequency band values FrequencyInfoDLs indicated by DownlinkConfigCommon in each serving cell configuration can indicate at least some overlapping bands. Since the above multiple TRPs operate based on multiple ServCellIndexes (e.g., ServCellIndex #1 and ServCellIndex #2), it is possible for each TRP to use a separate PCI. That is, the base station can allocate one PCI per ServCellIndex.
  • ServCellIndexes e.g., ServCellIndex #1 and ServCellIndex #2
  • the base station can appropriately select the value of ServCellIndex indicated by the cell parameter in QCL-Info to map the PCI suitable for each TRP and designate the SSB transmitted from either TRP 1 or TRP 2 as the source reference RS of the QCL configuration information.
  • this configuration applies one serving cell configuration that can be used for carrier aggregation (CA) of the terminal to multiple TRPs, there is a problem that it limits the degree of freedom of CA configuration or increases signaling burden.
  • CA carrier aggregation
  • Two TRPs with different PCIs can be operated with one serving cell configuration.
  • the base station can configure channels and signals transmitted from different TRPs through one serving cell configuration through [Operation Method 2]. Since the terminal operates based on one ServCellIndex (e.g., ServCellIndex #1), it is impossible for the terminal to recognize the PCI (e.g., PCI #2) allocated to the second TRP.
  • ServCellIndex #1 e.g., ServCellIndex #1
  • [Operation Method 2] can have more freedom in CA configuration than the above-described [Operation Method 1], but if multiple SSBs are transmitted from TRP 1 and TRP 2, the SSBs have different PCIs (e.g., PCI #1 and PCI #2), and the base station may not be able to map the PCI (e.g., PCI #2) of the second TRP through ServCellIndex indicated by the cell parameter in QCL-Info.
  • the base station can only designate the SSB transmitted from TRP 1 as the source reference RS of the QCL configuration information, and may not be able to designate the SSB transmitted from TRP 2.
  • [Operation Method 1] can perform multi-TRP operation for two TRPs with different PCIs through additional serving cell configuration without additional standard support, but [Operation Method 2] can operate based on the additional terminal capability report and base station configuration information below.
  • the terminal can report to the base station through the terminal capability that it can set additional PCIs other than the PCI of the serving cell through upper layer signaling from the base station.
  • the terminal capability may include two independent numbers, X1 and X2, or each X1 and X2 may be reported as an independent terminal capability.
  • - X1 represents the maximum number of additional PCIs that can be set for the terminal, and the PCI may be different from the PCI of the serving cell.
  • the time domain position and periodicity of the SSB corresponding to the additional PCI may be the same as those of the SSB of the serving cell.
  • - X2 means the maximum number of additional PCIs that can be set for the terminal, and the PCI at this time may be different from the PCI of the serving cell, and the time domain location and period of the SSB corresponding to the additional PCI at this time may mean different cases from the SSB corresponding to the PCI reported as X1.
  • the values reported as X1 and X2 through the terminal capability report can each have an integer value from 0 to 7.
  • the terminal may receive, from the base station, an upper layer signaling, SSB-MTCAdditionalPCI-r17, based on the terminal capability report described above, and the upper layer signaling may include at least a plurality of additional PCIs having different values from the serving cell, SSB transmit power corresponding to each additional PCI, and ssb-PositionInBurst corresponding to each additional PCI, and the maximum number of additional PCIs that can be set may be 7.
  • the terminal can assume that the SSB corresponding to the additional PCI of different values from the serving cell has the same center frequency, subcarrier spacing, and subframe number offset as the SSB of the serving cell.
  • the terminal can assume that the reference RS (e.g. SSB or CSI-RS) corresponding to the PCI of the serving cell is always connected to the activated TCI state, and in case of an additionally configured PCI having a different value from the serving cell, when there are one or more PCIs, it can assume that only one PCI among those PCIs is connected to the activated TCI state.
  • the reference RS e.g. SSB or CSI-RS
  • a terminal is configured with two different coresetPoolIndexes, and a reference RS corresponding to a serving cell PCI is connected to one or more activated TCI states, and a reference RS corresponding to an additionally configured PCI having a different value from that of the serving cell is connected to one or more activated TCI states, the terminal can expect that the activated TCI state(s) connected to the serving cell PCI will be connected to one of the two coresetPoolIndexes, and the activated TCI state(s) connected to the additionally configured PCI having a different value from that of the serving cell will be connected to the remaining one coresetPoolIndex.
  • the terminal capability report and the upper layer signaling of the base station for the above-described [Operation Method 2] can set an additional PCI with a different value from the PCI of the serving cell. If the above setting does not exist, the SSB corresponding to the additional PCI with a different value from the PCI of the serving cell that cannot be designated as the source reference RS can be used for the purpose of designating it as the source reference RS of the QCL configuration information.
  • the SSB that can be set for purposes such as RRM, mobility management, or handover
  • the configuration information for the SSB that can be set in the above-described upper layer signaling smtc1 and smtc2
  • it can be used to serve as a QCL source RS for supporting multiple TRP operations with different PCIs.
  • DMRS can be composed of multiple DMRS ports, and each port maintains orthogonality so as not to cause interference with each other by using CDM (code division multiplexing) or FDM (frequency division multiplexing).
  • CDM code division multiplexing
  • FDM frequency division multiplexing
  • the term for DMRS can be expressed by different terms depending on the user's intention and the purpose of using the reference signal.
  • the term DMRS is only provided as a specific example to easily explain the technical content of the present disclosure and to help the understanding of the present disclosure, and is not intended to limit the scope of the present disclosure. That is, it is obvious to a person having ordinary skill in the art to which the present disclosure belongs that the technical idea of the present disclosure can be implemented for any reference signal.
  • Fig. 8 is a diagram illustrating an example of DMRS patterns (type 1 and type 2) used for communication between a base station and a terminal in a 5G system. Two DMRS patterns can be supported in a 5G system, and two DMRS patterns are illustrated in Fig. 8.
  • reference numbers 801 and 802 correspond to DMRS type1, where reference number 801 represents a 1 symbol pattern and reference number 802 represents a 2 symbol pattern.
  • DMRS type1 (801, 802) is a DMRS pattern of a comb 2 structure and can be composed of two CDM groups, and different CDM groups can be FDMed.
  • the 1 symbol pattern (801) frequency-based CDM is applied to the same CDM group to distinguish two DMRS ports, and thus a total of four orthogonal DMRS ports can be set.
  • the 1 symbol pattern (801) can include a DMRS port ID mapped to each CDM group (the DMRS port ID for downlink can be represented by the illustrated number + 1000).
  • time/frequency-based CDM is applied to the same CDM group to distinguish four DMRS ports, and thus a total of eight orthogonal DMRS ports can be set.
  • the 2 symbol pattern (802) can include a DMRS port ID mapped to each CDM group (the DMRS port ID for downlink can be represented by the illustrated number + 1000).
  • DMRS type2 (803, 804) is a DMRS pattern in which FD-OCC (frequency domain orthogonal cover codes) are applied to frequency-adjacent subcarriers. It can be composed of three CDM groups, and different CDM groups can be FDMed.
  • 1 symbol pattern (803) frequency-based CDM is applied to the same CDM group, so that 2 DMRS ports can be distinguished, and thus a total of 6 orthogonal DMRS ports can be set.
  • 1 symbol pattern (803) can include DMRS port IDs mapped to each CDM group (DMRS port ID for downlink can be indicated by the illustrated number + 1000).
  • time/frequency-based CDM is applied to the same CDM group, so that 4 DMRS ports can be distinguished, and thus a total of 12 orthogonal DMRS ports can be set.
  • 2 symbol pattern (804) can include DMRS port IDs mapped to each CDM group (DMRS port ID for downlink can be indicated by the illustrated number + 1000).
  • DMRS patterns e.g., DMRS patterns (801, 802) or DMRS patterns (803, 804)
  • each DMRS pattern is a one symbol pattern (801 or 803) or two adjacent symbol patterns (802 or 804).
  • not only the DMRS port number is scheduled, but also the number of CDM groups scheduled together for PDSCH rate matching can be configured and signaled.
  • both of the above-described two DMRS patterns can be supported in DL and UL
  • DFT-S-OFDM discrete Fourier transform spread OFDM
  • Front-loaded DMRS refers to the first DMRS that is transmitted and received in the frontmost symbol in the time domain among DMRSs
  • additional DMRS refers to DMRS that is transmitted and received in the symbol later than the front-loaded DMRS in the time domain.
  • the number of additional DMRSs can be configured from a minimum of 0 to a maximum of 3.
  • the same pattern as the front-loaded DMRS may be assumed.
  • the additional DMRS when information about whether the DMRS pattern type described above is type 1 or type 2 for the front-loaded DMRS, information about whether the DMRS pattern is a 1-symbol pattern or an adjacent 2-symbol pattern, and information about the number of CDM groups used with the DMRS port are indicated, when an additional DMRS is additionally configured, it may be assumed that the additional DMRS has the same DMRS information as the front-loaded DMRS.
  • the downlink DMRS settings described above can be set via RRC signaling as shown in Table 6 below.
  • DMRS-DownlinkConfig SEQUENCE ⁇ dmrs-Type ENUMERATED ⁇ type2 ⁇ OPTIONAL, -- Need S dmrs-AdditionalPosition ENUMERATED ⁇ pos0, pos1, pos3 ⁇ OPTIONAL, -- Need S maxLength ENUMERATED ⁇ len2 ⁇ OPTIONAL, -- Need S scramblingID0 INTEGER (0..65535) OPTIONAL, -- Need S scramblingID1 INTEGER (0..65535) OPTIONAL, -- Need S phaseTrackingRS SetupRelease ⁇ PTRS-DownlinkConfig ⁇ OPTIONAL, -- Need M ... ⁇
  • dmrs-Type can set DMRS type
  • dmrs-AdditionalPosition can set additional DMRS OFDM symbols
  • maxLength can set 1 symbol DMRS pattern or 2 symbol DMRS pattern
  • scramblingID0 and scramblingID1 can set scrambling IDs
  • phaseTrackingRS can set PTRS (phase tracking reference signal).
  • the above-described uplink DMRS configuration can be set via RRC signaling as shown in Table 7 below.
  • DMRS-UplinkConfig :: SEQUENCE ⁇ dmrs-Type ENUMERATED ⁇ type2 ⁇ OPTIONAL, -- Need S dmrs-AdditionalPosition ENUMERATED ⁇ pos0, pos1, pos3 ⁇ OPTIONAL, -- Need R phaseTrackingRS SetupRelease ⁇ PTRS-UplinkConfig ⁇ OPTIONAL, -- Need M maxLength ENUMERATED ⁇ len2 ⁇ OPTIONAL, -- Need S transformPrecodingDisabled SEQUENCE ⁇ scramblingID0 INTEGER (0..65535) OPTIONAL, -- Need S scramblingID1 INTEGER (0..65535) OPTIONAL, -- Need S ...
  • OPTIONAL -- Need R transformPrecodingEnabled SEQUENCE ⁇ nPUSCH-Identity INTEGER (0..1007) OPTIONAL, -- Need S sequenceGroupHopping ENUMERATED ⁇ disabled ⁇ OPTIONAL, -- Need S sequenceHopping ENUMERATED ⁇ enabled ⁇ OPTIONAL, -- Need S ... ⁇ OPTIONAL, -- Need R ... ⁇
  • dmrs-Type can set DMRS type
  • dmrs-AdditionalPosition can set additional DMRS OFDM symbols
  • phaseTrackingRS can set PTRS
  • maxLength can set 1 symbol DMRS pattern or 2 symbol DMRS pattern
  • scramblingID0 and scramblingID1 can set scrambling ID0s
  • nPUSCH-Identity can set cell ID for DFT-s-OFDM
  • sequenceGroupHopping can disable sequence group hopping
  • sequenceHopping can enable sequence hopping.
  • FIG. 9 is a diagram illustrating an example of channel estimation using DMRS received on one PUSCH in a time band of a 5G system.
  • channel estimation when performing channel estimation for data decoding using DMRS, channel estimation can be performed within a PRG (precoding resource block group), which is a bundling unit, by using PRB bundling (physical resource blocks bundling) linked to a system band in a frequency band.
  • PRG precoding resource block group
  • PRB bundling physical resource blocks bundling
  • a base station can set a time domain resource allocation information table for a downlink data channel (PDSCH) and an uplink data channel (PUSCH) to a terminal through higher layer signaling (e.g., RRC signaling).
  • PDSCH downlink data channel
  • PUSCH uplink data channel
  • the time domain resource allocation information may include, for example, PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between a PDCCH being received and a slot-unit time interval between a PDSCH being scheduled by the received PDCCH being transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between a PDCCH being received and a slot-unit time interval between a PUSCH being scheduled by the received PDCCH being transmitted, denoted as K2), information on a position and a length of a start symbol at which a PDSCH or a PUSCH is scheduled within a slot, and at least one of a PDSCH or a PUSCH mapping type.
  • time domain resource allocation information for PDSCH can be set to a terminal through RRC signaling as shown in Table 8 below.
  • k0 represents PDCCH-to-PDSCH timing (i.e., slot offset between DCI and the scheduled PDSCH) in slot units
  • mappingType represents a PDSCH mapping type
  • startSymbolAndLength represents a start symbol and length of a PDSCH
  • repetitionNumber may represent the number of PDSCH transmission occasions according to a slot-based repetition scheme.
  • time domain resource allocation information for PUSCH may be set to a terminal through RRC signaling as shown in Table 9 below.
  • k2 represents PDCCH-to-PUSCH timing (i.e., slot offset between DCI and the scheduled PUSCH) in slot units
  • mappingType represents a PUSCH mapping type
  • startSymbolAndLength or StartSymbol and length represent a start symbol and a length of a PUSCH
  • numberOfRepetitions may represent a number of repetitions applied to a PUSCH transmission.
  • the base station may indicate at least one of the entries of the table for the time domain resource allocation information to the UE via L1 signaling (e.g., downlink control information (DCI)) (e.g., by a 'time domain resource allocation' field in the DCI).
  • DCI downlink control information
  • the UE may acquire time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.
  • FIG. 10 is a diagram illustrating an example of a method for resetting SSB transmission through dynamic signaling according to an embodiment.
  • the base station can reset SSB transmission configuration information by broadcasting bitmap '1010xxxx' (1004) through Group/Cell common DCI (Group/Cell common DCI, 1003) having nwes-RNTI (network energy saving-radio network temporary identifier, or, es-RNTI) to reduce the density of SSB transmission for energy saving.
  • Group/Cell common DCI Group/Cell common DCI, 1003
  • nwes-RNTI network energy saving-radio network temporary identifier, or, es-RNTI
  • transmission of SS block#1 (1005) and SSblock#3 (1006) can be canceled based on the bitmap (1004) set as the Group/Cell common DCI.
  • FIG. 10 provides a method (1001) for resetting SSB transmission through bitmap-based Group/Cell common DCI.
  • the base station can reset the ssb-periodicity set through upper layer signaling via group/cell common DCI.
  • timer information for indicating the application time of the group/cell common DCI
  • SSB can be transmitted through SSB transmission information reset to the group/cell common DCI during the set timer.
  • the base station can operate based on the SSB transmission information set by the existing upper layer signaling. This may correspond to an operation of changing the setting from the general mode to the energy saving mode via the timer, and may correspond to the resetting of the SSB configuration information due to this.
  • the base station can set the application time and period of the SSB configuration information reset through the group/cell common DCI to the terminal using offset and interval information.
  • the terminal may not monitor the SSB during the set interval from the moment of receiving the group/cell common DCI to the moment of applying the offset.
  • FIG. 11 is a diagram illustrating an example of a method for resetting BWP and BW through dynamic signaling according to an embodiment.
  • a terminal can operate with a BWP or BW activated through upper layer signaling and L1 signaling from a base station (1101). For example, a terminal can operate with a Full BW of 100MHz with a fixed power PSD B. At this time, the base station can adjust the BW and BWP to activate a narrower BW of 40MHz for the terminal with the same power PSD B for energy saving (1102). At this time, the BW or BWP adjustment operation for energy saving of the base station can be set to match the BWP and BW settings that are set UE-specifically through group common DCI and cell specific DCI (1103). For example, UE#0 and UE#1 can have different BWP configurations and locations.
  • the base station can set the BW and BWP of all terminals to be the same.
  • BWP or BW in the operation for energy saving can be set to one or more, and this can be used to set BWP for each terminal group.
  • DRX discontinuous reception
  • FIG. 12 is a diagram illustrating an example of a method for resetting DRX through dynamic signaling according to an embodiment.
  • the base station can set DRX for each terminal specifically through upper layer signaling.
  • each terminal can be set to different drx-LongCycle or drx-ShortCycle, drx-onDurationTimer, and drx-InactivityTimer.
  • the base station can set the DRX settings for each terminal specifically through L1 signaling in a UE group specific or cell specific manner for energy saving (1201). Through this, the base station can obtain the same effect of saving power for each terminal through DRX for energy saving.
  • FIG. 13 is a diagram illustrating an example of a DTx method for base station energy saving.
  • the base station can configure DTx for energy saving through higher layer signaling (e.g. new SIB or RRC signaling for DTx) and L1 signaling (DCI).
  • the base station can set dtx-onDurationTimer (1305) for transmitting a reference signal for measuring PDCCH for scheduling DL SCH for DTx operation, RRM measurement, beam management, and path loss, dtx-InactivityTimer (1306) for receiving PDSCH after receiving PDCCH for scheduling DL SCH, synchronization signal (SS, 1303) setting information for synchronization before dtx-onDurationTimer, dtx-offset (1304) for setting an offset between SS and dtx-onDurationTimer, and dtx-(Long)Cycle (1302) for DTx to operate periodically based on the setting information.
  • SS synchronization signal
  • SS synchronization signal
  • dtx-offset 1304
  • dtx-cycle can be set to multiple long cycles and short cycles.
  • the base station considers the state of turning off (or deactivating) the transmitter, and therefore may not transmit DL CCH, SCH, and DL RS. That is, the base station can transmit downlink (PDCCH, PDSCH, RS, etc.) only during SS, dtx-onDurationTimer, and dtx-InactivityTimer during the DTx operation.
  • the number of SS-gapbetweenBurst or SS bursts can be additionally set as additional information of the configured SS.
  • Figure 14 is a diagram for explaining an example of the operation of a base station according to gNB WUS.
  • the base station can keep the transmitter end in the off (or inactive) state during the inactive state (or sleep mode) of the base station for energy saving. Thereafter, the base station can receive a gNB WUS (1402) for activating the sleep mode of the base station from the terminal. Thereafter, when the base station receives the WUS (1402) from the terminal through the Rx terminal, the base station can change the Tx terminal to the on (or active) state (1403). Thereafter, the base station can perform downlink transmission to the terminal. At this time, the base station can perform synchronization after Tx on and perform control information and data transmission.
  • a gNB WUS 1402
  • the base station can change the Tx terminal to the on (or active) state (1403).
  • the base station can perform downlink transmission to the terminal. At this time, the base station can perform synchronization after Tx on and perform control information and data transmission.
  • various uplink signals for example, a physical random access channel (PRACH), a physical uplink control channel (PUCCH) including a scheduling request (SR), an acknowledgement (ACK), etc.
  • PRACH physical random access channel
  • PUCCH physical uplink control channel
  • SR scheduling request
  • ACK acknowledgement
  • the base station can save energy, and at the same time, the terminal can improve latency.
  • the base station can set a WUS occasion for receiving the gNB WUS and a synchronization reference signal (sync RS) for synchronization before the terminal transmits the gNB WUS.
  • SSB, TRS (tracking RS), Light SSB (PSS and SSS), continuous SSBs, or new RS (for example, continuous PSS and SSS) can be considered as the synchronization reference signal
  • PRACH, scheduling request on PUCCH, or sequence based signal can be considered as the WUS.
  • the synchronization reference signal (1504) for the terminal to activate the deactivation mode for energy saving of the base station and the WUS occasion for receiving the WUS can be repeatedly set as a WUS-RS period (1405).
  • one embodiment illustrates a 1-to-1 mapping of a synchronization reference signal and a WUS occasion, but is not limited thereto, and may be N-to-1 mapping, 1-to-N mapping, or N-to-M mapping.
  • FIG. 15 is a diagram illustrating an example of a spatial domain (SD) adaptation method of a base station for energy saving according to an embodiment.
  • SD spatial domain
  • the base station can adjust the transmit antenna port per RU (remote unit) for energy saving. Since the PA of the base station accounts for most of the energy consumption of the base station, the base station can turn off the transmit antenna to save energy (1501). At this time, the base station can adjust the number of activated transmit antennas for each terminal group or terminal by referring to the RSRP (reference signal received power), CQI (channel quality indicator), and RSRQ (reference signal received quality) of the terminal to determine whether the transmit antenna can be turned off and transmit a signal. At this time, the base station can set beam information and reference signal information (CSI resource or CSI report setting) according to the on/off of the antenna to the terminal through upper layer signaling (RRC signaling) or DCI.
  • RRC signaling upper layer signaling
  • the terminal can set different antenna information for each BWP and reset the antenna information according to the BWP change.
  • the base station can receive CSI feedback from the terminal to determine whether SD adaptation is possible and determine SD adaptation based on the CSI feedback. At this time, the base station can receive multiple CSI feedbacks based on antenna structure hypotheses of multiple antenna patterns for SD adaptation from the terminal.
  • the base station can apply two types of SD adaptation for energy saving (1502).
  • Type 1 SD adaptation (1503) is that the base station changes the number of antenna ports while maintaining the number of physical antenna elements per antenna port (i.e., logical port).
  • RF characteristics (e.g., transmit power, beam) per port of the base station can be the same.
  • the terminal can perform measurement by combining CSI-RSs of the same port during CSI measurement (e.g., L1-RSRP, L3-RSRP, etc.).
  • each port of CSI-RS #0 and CSI-RS #1 can include the same number of physical antenna elements.
  • Type 2 SD adaptation (1504), is that the base station has the same number of antenna ports (i.e., logical ports) and turns on/off physical antenna elements per port. In this case, RF characteristics per port will be different, and the terminal should perform measurements by distinguishing between cases where Type 2 SD adaptation is applied and cases where it is not applied for the CSI-RS of the same port during CSI measurement. For example, in CSI-RS #0 and CSI-RS #1, the number of ports is maintained, but the number of physical antenna elements corresponding to each port is changed.
  • the base station can save energy through the two representative types of SD adaptation methods mentioned above.
  • the energy consumption of the base station can be reduced.
  • the above methods can be set simultaneously through one or more combinations.
  • Various embodiments of the present disclosure provide a new cell definition and on-demand cell activation method through WUS transmitted by a terminal for reducing energy consumption of a base station in a wireless communication system.
  • Various embodiments of the present disclosure define a carrier selection method of WUS for activating an on-demand cell and a WUS occasion (WO) for WUS transmission and reception.
  • WO WUS occasion
  • retransmission and repetition operations of WUS are provided. Through this, a base station can save energy by keeping more parts of a non-on-demand cell in an inactive state for a long time.
  • upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.
  • L1 signaling may be signaling corresponding to at least one or a combination of one or more of the following physical layer channels or signaling methods.
  • Non-scheduled DCI e.g. DCI not intended for scheduling downlink or uplink data
  • determining the priority between A and B can be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.
  • slot used in the present disclosure below is a general term that may refer to a specific time unit corresponding to a transmit time interval (TTI), and specifically may mean a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.
  • TTI transmit time interval
  • port in the present disclosure below may be used interchangeably with an antenna port.
  • the present disclosure below describes the examples through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.
  • FIG. 16 is a diagram illustrating an example of a concept of cells having different functions for energy saving according to an embodiment.
  • a base station can define cell#0 (1600) and cell#1-X (e.g., cell#1-1 (1610), cell#1-2 (1620)) having different functions.
  • Cell type 1 e.g., cell#0 (1600), Access/sync cell
  • the base station can periodically transmit SSB and new synchronization signal for terminals in idle/inactive RRC state through cell#0, and also paging and system information can be transmitted through cell#0.
  • the above paging and system information may include at least one of configuration information for cell #1-x capable of processing packets, such as carrier frequency of cell #1-x, physical cell ID, and WUS configuration information.
  • the WUS configuration information may include at least one of information for WUS and information for WUS occasion.
  • Cell type 2 (e.g., cell #1-x (1610, 1620, 1630), Data cell) can process packets of terminals and base stations. More specifically, the base station can process packets of terminals in connected RRC state through cell #1-X. Therefore, a cell of cell type 2 can be selectively activated only when there is a packet according to traffic on-demand. If the base station initially activates cell #1-X for packet processing, cell #1-X transmits SS (synchronization signal, for example, SSB, CSI-RS, TRS, or a new SS) to synchronize the terminal and cell #0, and a terminal that has performed initial access to cell #0 or is synchronized to cell #0 can receive SS of cell #1-x and perform handover to cell #1-x. At this time, cell1-X to be activated on-demand can be determined by the base station serving cell#0, the base station serving cell#1-X, or the terminal attached to cell#0.
  • SS synchronization signal
  • a single base station may support only cell type 1, only cell type 2, or both cell type 1 and cell type 2. Additionally, one or more cells of cell type 2 may be connected to one or more cells of cell type 1. Additionally, coordination may be performed between cells of cell type 1 to activate cells of cell type 2.
  • a cell selection method for a terminal to process packets appropriately according to traffic in a cell deployment situation having cells performing different functions is provided. More specifically, the present disclosure provides a cell selection method and a signaling method by a base station or a terminal.
  • the base station can maximize the energy saving effect and guarantee service performance by activating an appropriate data cell for a terminal.
  • FIG. 17 is a diagram illustrating an example of an on-demand cell selection method for energy saving of a base station according to an embodiment.
  • cell type 2 capable of packet transmission may be set to process traffic within the coverage of cell type 1 (e.g., Access/Sync cell) that performs mobility and initial connection functions.
  • cell type 1 e.g., Access/Sync cell
  • an appropriate Data cell for processing traffic may be selected using one of the following methods or a combination thereof.
  • the base station can select an appropriate data cell for each terminal based on geometry information of the terminal (e.g., location information, sector information, and beam-based direction information, etc.) (1700). For example, when the terminal (1730) is initially connected to Access/Sync cell#0 (1710), the terminal can handover or connect from the Access/Sync cell#0 to one of data cells#1 to#3 (1720, 1722, 1724) in the Access/Sync cell#0 for packet processing.
  • the base station can select an appropriate data cell for the terminal as an access cell, and the base station can activate the selected data cell.
  • the base station can select data cell#1 (1720) by using beam information (beam direction information) for synchronization used/reported by the terminal in the Access/Sync cell.
  • beam information beam direction information
  • On-demand cell selection based on an Access/Sync cell base station can be performed through the above method 1.
  • the terminal (1780) can activate a data cell for transmitting and receiving packets via UL WUS for traffic processing (1750).
  • a terminal connected to Access/Sync cell#0 (1760) can activate surrounding data cells (1770, 1772, 1774) for traffic processing.
  • the terminal can transmit a WUS for activating the data cell.
  • the WUS can be a sequence-based signal or a conventional PUCCH, PRACH or similar signal, and the base station of the data cell can have a WUS receiver (WUS receiver, WUR) for receiving a separate WUS.
  • the terminal can repeatedly transmit or retransmit the WUS, and the terminal can determine the transmission power and carrier frequency of the WUS based on the information set via the Access/Sync cell and transmit the WUS.
  • the data cell-related information set by the terminal via the Access/Sync cell can include at least one of the following information, for example.
  • Periodicity of WUS occasion 20 ms or 40 ms like as RACH occasion periodicity
  • the base station serving the data cell (Data cell#1(1770), Data cell#3(1774)) that received the WUS from the terminal is activated and can transmit SS to the terminal and perform data transmission and reception for the subsequent packet.
  • the terminal after receiving the WUS, it is also possible to determine whether the data cell or access cell is activated based on measurement information such as RSRP for the WUS, or after all data cells that received the WUS are activated, the terminal can receive SS from one or more activated data cells and select an appropriate data cell for data transmission and reception.
  • a base station serving an inactive cell can save energy by selecting an appropriate data cell for the terminal, and the terminal can receive service through the selected data cell.
  • An embodiment of the present disclosure provides a signaling procedure for data cell selection based on the WUS.
  • FIG. 18a is a diagram illustrating an example of a procedure for on-demand cell selection for energy saving of a base station according to an embodiment of the present disclosure.
  • a terminal (1802) can perform data cell selection through WUS transmission (1800).
  • a sync/access cell (1804) can always be activated (1820, Tx/Rx on, which can mean power on of transmission RF and reception RF devices including a modem), and data cells cell2-A (1806), cell2-B (1808), and cell2-C (1810) have RFs for transmission and reception powered off, but WUR can always be on (1822).
  • power off can be understood as deep/ultra deep sleep.
  • the deep/ultra deep sleep means that most of the components of the base station are powered off, and for example, a modem, backhaul, memory, cooler, etc. can all be turned off.
  • the sync/access cell and the data cell can exchange information for network energy saving (1826).
  • Information for network energy saving that is transmitted and received between the sync/access cell and the data cell may include at least one of the following information: a network energy saving scheme applied to each cell, information about a WUS that can be supported by each cell, and at least one of the information included in the data cell-related information described above.
  • the terminal can perform a RACH procedure for initial access to the Access/Sync cell (1830).
  • the terminal can receive configuration information of a data cell associated with the corresponding cell from the Access/Sync cell (1832).
  • the configuration information of the data cell can refer to the data cell related information described above.
  • the terminal can transmit a WUS to one or more data cells (1834).
  • base stations that have received the WUS transmitted from the terminal can be activated (Tx/Rx On) and transmit a reference signal for synchronization (or access) to the terminal (1836).
  • the terminal can measure the reference signal, select a data cell based on the measurement result (1838), and perform a handover (or access) to the data cell (1840).
  • FIG. 18b is a diagram illustrating an example of a procedure for on-demand cell selection for energy saving of a base station according to an embodiment of the present disclosure.
  • the base station of the access cell may perform data cell selection (1850) based on the WUS transmitted by the terminal (1852).
  • the sync/access cell (1854) may always be activated (Tx/Rx on, 1870), and the data cells cell2-A (1856), cell2-B (1858), and cell2-C (1860) may have RF for transmission and reception powered off, but WUR may always be on (1872).
  • the sync/access cell and the data cell may exchange information for network energy saving with each other (1876).
  • the information for the network energy saving may refer to the above-described content.
  • the terminal may receive SS and select a cell to access (1878), and then perform a RACH procedure for initial access to the Access/Sync cell (1880).
  • the terminal may receive configuration information of a data cell associated with the corresponding cell from the Access/Sync cell (1882).
  • the configuration information of the data cell may refer to the data cell-related information described above.
  • the terminal may transmit a WUS to one or more data cells (1884).
  • the base stations serving the data cell that received the WUS transmitted from the terminal can report the measurement results of measuring the WUS, such as information including RSRP and RSRQ, to the Access/Sync cell (1886).
  • whether to report to the Access/Sync cell based on the WUS measurement can be determined by the data cell based on the WUS measurement results.
  • the Sync/Access cell can determine one data cell based on the received WUS measurement report (1888) and activate the data cell (1890).
  • the activated (Tx/Rx On) data cell can transmit a reference signal for synchronization (or connection) to the terminal (1892).
  • the terminal can receive the reference signal from the data cell and handover (or connection) to the data cell (1894). Alternatively, if the reception status of the reference signal from the data cell is not good, the terminal can transmit WUS again.
  • the terminal or base station can select an appropriate data cell based on the WUS of the terminal. Through this, a specific optimal data cell is selected for each terminal, thereby enabling cell selection that considers the channel between the data cell and the terminal. Through this, the base station can obtain an energy saving effect from the inactive data cell, and the terminal can obtain a service with good performance.
  • the base station can maximize the energy saving effect and guarantee service performance by activating an appropriate data cell for a terminal.
  • FIG. 19a and FIG. 19b are diagrams illustrating an example of a WUS transmission method for activating data cells for energy saving of a base station according to an embodiment.
  • the terminal can determine a carrier (or/and a frequency domain resource allocated to the carrier) and a WUS occasion (or a time domain resource allocated for WUS transmission) to transmit the WUS based on the WUS configuration information for data cell activation set from the Access/Sync cell.
  • the WUS can be repeatedly transmitted or retransmitted on different carriers or occasions.
  • the following describes a cell activation operation based on retransmission of WUS and a cell activation operation based on repeated transmission of WUS.
  • FIG. 19a is a diagram illustrating an example of a WUS transmission method for activating data cells for energy saving of a base station according to an embodiment.
  • the terminal (1908) may receive WUS configuration information related to a data cell associated with the corresponding cell from the Access/Sync cell (1902) after the RACH procedure (1910) in order to initially access the Access/Sync cell (1912).
  • the WUS configuration information (WUS Config) for the corresponding data cell may include candidate carrier information of the corresponding data cell and information on WUS occasion and WUS format for each carrier.
  • the terminal may be configured with a WUS response window for monitoring feedback on the WUS after WUS transmission.
  • the WUS response window configuration information may be included in the WUS configuration information or the value of the WUS response window may be determined based on UE capability.
  • the WUS configuration information may include at least one of the following information.
  • Periodicity of WUS occasion 20 ms or 40 ms like as RACH occasion periodicity
  • the terminal can perform the first WUS transmission at WUS occasion #2 (1914) through cell#2 of 28GHz based on the configuration information. If the terminal does not receive any feedback (e.g., Ack) during the WUS response window #0 (1916) corresponding to Cell#2 after the first WUS transmission, the terminal can perform WUS retransmission at WUS occasion #1 (1918) through Cell#1 (3.5GHz).
  • Ack any feedback
  • the terminal can handover (or connect) to Cell#1.
  • the terminal can receive the priority for WUS transmission/retransmission of the candidate carriers from the Access/Sync cell.
  • the above priority information may be included in the above WUS configuration information or may be predetermined. Thereafter, the terminal may perform a WUS retransmission operation based on the above priority.
  • FIG. 19b is a diagram illustrating another example of a WUS transmission method for activating data cells for energy saving of a base station according to an embodiment.
  • the terminal (1958) may receive WUS configuration information related to a data cell associated with the Access/Sync cell (1952) from the Access/Sync cell after the RACH procedure (1960) in order to initially access the Access/Sync cell.
  • the WUS configuration information (WUS Config) for the data cell may include candidate carrier information of the data cell and information on WUS occasion and WUS format for each carrier.
  • the terminal may be configured with a WUS response window for monitoring feedback on the WUS after WUS transmission.
  • the WUS response window may be included in the WUS configuration information or the value of the WUS response window may be determined based on the terminal capability.
  • For the WUS configuration information reference may be made to the above-described content.
  • the terminal when the terminal is set to ⁇ Cell#2 (28GHz) (1956), Cell#1 (3.5GHz) ⁇ as the candidate carrier of the data cell from the base station and 2 is set as the norepetition (number of repetitions) of WUS, the terminal can perform the initial WUS transmission at WUS occasion #1 (1864) through cell#1 (1954) of 3.5GHz based on the above-mentioned setting information, and thereafter repeatedly transmit the WUS at WUS occasion #2 (1966) through cell#2 (1956) of 28GHz.
  • the terminal can monitor the feedback during the corresponding WUS response window #0 (1968) from the time of transmitting the WUS in Cell#1, and can continuously monitor the feedback for the WUS response window #1 (1970) after transmitting the WUS in Cell#2.
  • the terminal receives an Ack feedback (1972) including the Cell#2 index in WUS response window#1, the terminal can handover (or connect) to Cell#2.
  • the order of carriers for WUS repeat transmission (or the priority of carrier/data cell) can be set from the Access/Sync cell (in this case, the priority information can be included in the WUS configuration information) or can be sorted from a low carrier frequency or a high carrier frequency according to traffic.
  • the gap between WUS repetitions can be set from the base station to the terminal or determined by the terminal capability considering the carrier switching time.
  • the terminal can determine the carrier of the data cell and activate the data cell through the WUS.
  • the WUS occasions can overlap by carrier, and the carrier frequency of the WUS response window is the carrier frequency of the Access/Sync cell, the carrier frequency of the corresponding data cell, or the carrier frequency for a specific WUS, and the terminal can receive and monitor the feedback of the WUS through the carrier frequency.
  • the third embodiment of the present disclosure provides a cell selection procedure for energy saving of a base station in a 5G or 6G system. More specifically, an example of a procedure of a terminal and a base station for cell selection and WUS transmission for energy saving of a base station in a 5G or 6G system is described.
  • FIG. 20 is a flowchart illustrating an example of an operation of a terminal that applies a cell selection method for energy saving of a base station in a 5G or 6G system to which the present disclosure is applied.
  • the terminal can perform initial access and synchronization based on cell type 1 (e.g., Cell#0 or Access/Sync cell) (2001). Thereafter, the terminal can receive configuration information for a cell of cell type 2 (e.g., Cell#1-X or Data cell) through upper layer signaling and L1 signaling from cell type 1 (2002). At this time, the configuration information can include configuration information of WUS.
  • the configuration information for the data cell and the WUS configuration information can refer to the contents described above.
  • the terminal can check a WUS occasion and a carrier for WUS transmission based on the configuration information (2003). The terminal can transmit WUS through the selected carrier and monitor WUS feedback during a WUS response window (2004).
  • the terminal determines whether WUS feedback (Ack) has been received, and if the terminal receives feedback of WUS during the WUS response window, the terminal can access the corresponding data cell (2005). If the terminal does not receive the WUS feedback or receives a Nack (negative acknowledgements), the terminal can retransmit or/and repeat the WUS and monitor the WUS feedback again (2006).
  • WUS feedback Ack
  • Nack negative acknowledgements
  • FIG. 21A is a flowchart illustrating an example of a base station operation serving a cell of cell type 1 applying a cell selection method for energy saving of a base station in a 5G or 6G system to which the present disclosure is applied.
  • a base station may transmit a periodic reference signal to a terminal for initial access & synchronization and mobility support (2101).
  • the periodic reference signal may be, for example, at least one of SSB, PSS, SSS or newly defined SS.
  • paging and system information may also be transmitted periodically from the base station.
  • the base station may transmit configuration information for a cell of cell type 2 to the terminal (2102).
  • the configuration information may include WUS configuration information.
  • the configuration information for the data cell and the WUS configuration information may refer to the contents described above.
  • the base station may receive a WUS measurement report including a result of measuring a WUS transmitted by the terminal from a cell of Cell type 2 (or a base station serving the cell) and perform data cell selection (2103). If the cell selection operation of the base station is not performed, step 2103 may be omitted.
  • FIG. 21b is a flowchart illustrating an example of a base station operation serving a cell of cell type 2 for energy saving of the base station in a 5G or 6G system to which the present disclosure is applied.
  • the base station can monitor WUS at a WUS occasion through WUR based on WUS configuration information set through Access/Sync cell or WUS-related information determined in advance (2104).
  • the WUS configuration information can refer to the content described above.
  • the Tx and Rx RF of the base station can be powered off, but the WUR can be powered on.
  • the base station can measure the WUS and determine whether to activate the cell to determine whether to activate the main radio, and/or report the WUS measurement to the Access/Sync cell (2105).
  • the base station can compare the WUS measurement result, for example, RSRP and RSRQ, with a threshold value that is determined in advance or set by the base station serving the cell type 1 cell (2106), and if the WUS measurement result is greater than (or greater than or equal to) the threshold value, the base station can transmit an Ack to the terminal (2107). Afterwards, the cell type 2 base station can be activated after the Ack transmission and the terminal can be attached to the cell of the cell type 2 (2107).
  • the WUS measurement result for example, RSRP and RSRQ
  • FIG. 22 is a block diagram of a terminal according to one embodiment of the present disclosure.
  • the terminal (2200) may include a transceiver (2201), a control unit (e.g., a processor) (2202), and a storage unit (e.g., a memory) (2203).
  • the transceiver (2201), the control unit (2202), and the storage unit (2203) of the terminal (2200) may operate according to at least one of the methods corresponding to the above-described embodiments or a combination thereof.
  • the components of the terminal (2200) are not limited to the illustrated example. According to other embodiments, the terminal (2200) may include more or fewer components than the components described above.
  • the transceiver (2201), the control unit (2202), and the storage unit (2203) may be implemented in the form of a single chip.
  • the transceiver (2201) may be configured with a transmitter and a receiver according to one embodiment.
  • the transceiver (2201) may transmit and receive signals with a base station.
  • the signals may include control information and data.
  • the transceiver (2201) may be configured to include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal.
  • the transceiver (2201) may receive a signal through a wireless channel and output the same to the control unit (2202), and transmit a signal output from the control unit (2202) through the wireless channel.
  • the control unit (2202) may control a series of procedures that the terminal (2200) may operate according to the embodiments of the present disclosure described above.
  • the control unit (2202) may perform or control an operation of the terminal to perform at least one or a combination of the methods according to the embodiments of the present disclosure.
  • the control unit (2202) may include at least one processor.
  • the control unit (2202) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer (e.g., an application).
  • CP communication processor
  • AP application processor
  • the storage unit (2203) can store control information (e.g., information related to channel estimation using DMRSs transmitted on a PUSCH included in a signal acquired from the terminal (2200)) or data, and can have an area for storing data required for controlling the control unit (2202) and data generated during control by the control unit (2202).
  • control information e.g., information related to channel estimation using DMRSs transmitted on a PUSCH included in a signal acquired from the terminal (2200)
  • data can have an area for storing data required for controlling the control unit (2202) and data generated during control by the control unit (2202).
  • Figure 23 is a block diagram of a base station according to one embodiment.
  • the base station (2300) may include a transceiver (2301), a control unit (e.g., a processor) (2302), and a storage unit (e.g., a memory) (2303).
  • the transceiver (2301), the control unit (2302), and the storage unit (2303) of the base station (2300) may operate according to at least one or a combination of the methods corresponding to the above-described embodiments.
  • the components of the base station (2300) are not limited to the illustrated example. According to other embodiments, the base station (2300) may include more or fewer components than the above-described components.
  • the transceiver (2301), the control unit (2302), and the storage unit (2303) may be implemented in the form of a single chip.
  • the transceiver (2301) may be configured with a transmitter and a receiver according to one embodiment.
  • the transceiver (2301) may transmit and receive signals with a terminal.
  • the signal may include control information and data.
  • the transceiver (2301) may be configured to include an RF transmitter that up-converts and amplifies a frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency.
  • the transceiver (2301) may receive a signal through a wireless channel and output the same to the control unit (2302), and transmit a signal output from the control unit (2302) through the wireless channel.
  • the control unit (2302) may control a series of procedures so that the base station (2300) may operate according to the embodiments of the present disclosure described above.
  • the control unit (2302) may perform or control the operation of the base station to perform at least one or a combination of the methods according to the embodiments of the present disclosure.
  • the control unit (2302) may include at least one processor.
  • the control unit (2302) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer (e.g., an application).
  • CP communication processor
  • AP application processor
  • the storage unit (2303) can store control information (e.g., information related to channel estimation generated using DMRSs transmitted on a PUSCH determined by the base station (2300), data, control information received from a terminal, or data, and can have an area for storing data required for controlling the control unit (2302) and data generated during control by the control unit (2302).
  • control information e.g., information related to channel estimation generated using DMRSs transmitted on a PUSCH determined by the base station (2300), data, control information received from a terminal, or data, and can have an area for storing data required for controlling the control unit (2302) and data generated during control by the control unit (2302).

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente divulgation se rapporte à un système de communication 5G ou 6G permettant de prendre en charge des débits de transmission de données supérieurs. La présente divulgation concerne un procédé et un dispositif d'économie d'énergie d'une station de base.
PCT/KR2024/004697 2023-04-13 2024-04-09 Procédé et dispositif d'économie d'énergie dans système de communication sans fil Pending WO2024215047A2 (fr)

Applications Claiming Priority (2)

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KR1020230048738A KR20240152566A (ko) 2023-04-13 2023-04-13 무선 통신 시스템의 에너지 세이빙을 위한 방법 및 장치
KR10-2023-0048738 2023-04-13

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WO2024215047A3 WO2024215047A3 (fr) 2025-06-26

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CN119997053A (zh) * 2025-01-17 2025-05-13 中国信息通信研究院 一种信令指示方法和设备

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US10548182B2 (en) * 2017-08-21 2020-01-28 Qualcomm Incorporated Beam management for connected discontinuous reception with advanced grant indicator
WO2019139691A1 (fr) * 2018-01-10 2019-07-18 Kyocera Corporation Transmission d'un signal de réveil à des dispositifs mobiles à une fréquence porteuse alternative
KR20200121726A (ko) * 2019-04-16 2020-10-26 한국전자통신연구원 이동 통신 시스템에서 단말의 저전력 소모 동작을 위한 방법 및 장치
US12376035B2 (en) * 2019-11-15 2025-07-29 Lenovo (Beijing) Ltd. Method and apparatus for WUS detection
BR112022014294A2 (pt) * 2020-01-31 2022-09-20 Qualcomm Inc Interação do sinal de despertar (wus) com a recepção de sinal de referência de posicionamento (prs) de downlink em uma rede não cabeada

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* Cited by examiner, † Cited by third party
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CN119997053A (zh) * 2025-01-17 2025-05-13 中国信息通信研究院 一种信令指示方法和设备

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