Method and apparatus for transmitting / receiving signals for wireless communication

Abstract

According to an embodiment of the present disclosure, there is a reduced ability such that a terminal supporting a bandwidth less than a specific bandwidth can detect a physical broadcast channel (PBCH) signal through a synchronization signal block (SSB) on a first downlink (DL) bandwidth part (BWP), obtain a part of system information including a master information block (MIB) carried by the PBCH signal from among a plurality of first system information provided on the first DL BWP, and obtain second system information provided on a second DL BWP different from the first DL BWP.

Description

Technical Field

[0001] The present disclosure relates to wireless communication, and more particularly, to a method and apparatus for transmitting or receiving uplink / downlink signals in a wireless communication system. Background Art

[0002] Generally, wireless communication systems are evolving to differently cover wide ranges to provide communication services such as audio communication services, data communication services, etc. Wireless communication is a multiple access system capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). For example, the multiple access system may be any one of a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, and a single carrier frequency division multiple access (SC-FDMA) system. Summary of the Invention

[0003] Technical Problem

[0004] An object of the present disclosure is to provide a method for more efficiently transmitting and receiving signals in a wireless communication system in which different types of user equipment (UE) operate.

[0005] The object of the present disclosure is not limited to what has been specifically described above, and other objects that the present disclosure can achieve will be more clearly understood from the following detailed description.

[0006] Technical Solution

[0007] In one aspect of the present disclosure, there is provided a method for a user equipment (UE) to receive signals in a wireless communication system based on the 3rd Generation Partnership Project (3GPP). The method may include: detecting a physical broadcast channel (PBCH) signal in a synchronization signal block (SSB) on a first downlink (DL) bandwidth part (BWP); obtaining partial system information including a master information block (MIB) carried by the PBCH signal from among first system information provided on the first DL BWP; and obtaining second system information provided on a second DL BWP different from the first DL BWP. Based on the UE being a second type of UE having a reduced ability to support a smaller bandwidth than a first type of UE, the UE may be configured to: perform a BWP switch from the first DL BWP to the second DL BWP; and obtain the second system information provided on the second DL BWP as the remaining part in addition to the partial system information obtained on the first DL BWP.

[0008] The UE may be configured to perform cell access based on multiple initial DL BWPs.

[0009] The first DL BWP and the second DL BWP may be the first initial DL BWP and the second initial DL BWP, respectively.

[0010] The first DL BWP may be related to the bandwidth of a first type of UE, and the second DL BWP may be related to the bandwidth of a second type of UE.

[0011] The PBCH signal on the first DL BWP may be a common signal for the first type of UE and the second type of UE.

[0012] The second system information may be information for the second type of UE rather than the first type of UE. The second system information may include at least one second type system information block (SIB) for the second type of UE.

[0013] The UE obtaining partial system information on the first DL BWP may include: obtaining a first control resource set (CORESET) configuration and a first common search space (CSS) configuration from the MIB, where the first CORESET configuration and the first CSS configuration may be related to control information scheduling a first type system information block 1 (SIB1) for the first type of UE; and obtaining the first type SIB1 based on the first CORESET configuration and the first CSS configuration.

[0014] The UE obtaining the second system information on the second DL BWP may include: obtaining at least one second type of SIB provided on the second DL BWP based on the first type SIB1.

[0015] The UE obtaining partial system information on the first DL BWP may include obtaining a first CORESET configuration and a first CSS configuration from the MIB, where the first CORESET configuration and the first CSS configuration may be related to control information scheduling a first type SIB1 for the first type of UE.

[0016] The UE obtaining the second system information on the second DL BWP may include: obtaining at least one of a second CORESET configuration or a second CSS configuration on the second DL BWP by applying a time / frequency offset to at least one of the first CORESET configuration or the first CSS configuration; and obtaining at least one second type of SIB provided on the second DL BWP based on at least one of the second CORESET configuration or the second CSS configuration.

[0017] In another aspect of the present disclosure, a processor-readable storage medium is provided, on which a program for executing the above method is stored.

[0018] In another aspect of the present disclosure, a device for 3GPP-based wireless communication is provided. The device may include: a memory configured to store instructions; and a processor configured to perform operations by executing the instructions. The operations performed by the processor may include: detecting a PBCH signal in an SSB on a first DL BWP; obtaining partial system information including the MIB carried by the PBCH signal from among first system information provided on the first DL BWP; and obtaining second system information provided on a second DL BWP different from the first DL BWP. Based on the device being a second type of device having a reduced ability to support a smaller bandwidth than a first type of device, the processor may be configured to: perform a BWP switch from the first DL BWP to the second DL BWP; and obtain the second system information provided on the second DL BWP as the remaining portion in addition to the partial system information obtained on the first DL BWP.

[0019] The device may further include a transceiver configured to transmit and receive radio signals under the control of the processor.

[0020] The device may be a UE for 3GPP-based wireless communication.

[0021] The device may be an application specific integrated circuit (ASIC) or a digital signal processing device.

[0022] In another aspect of the present disclosure, a method for a base station to transmit signals in a 3GPP-based wireless communication system is provided. The method may include: transmitting a PBCH signal in an SSB on a first DL BWP; and transmitting second system information on a second DL BWP different from the first DL BWP. The base station may be configured to: support both a first type of UE and a second type of UE having a reduced ability to support a smaller bandwidth than the first type of UE; provide partial system information including the MIB carried by the PBCH signal to the second type of UE by transmitting the first system information on the first DL BWP; and provide the remaining system information to the second type of UE by transmitting the second system information on the second DL BWP.

[0023] In yet another aspect of the present disclosure, a base station configured to transmit signals in a 3GPP-based wireless communication system is provided. The base station may include: a memory configured to store instructions; and a processor configured to perform operations by executing the instructions. The operations performed by the processor may include: transmitting a PBCH signal in an SSB on a first DL BWP; and transmitting second system information on a second DL BWP different from the first DL BWP. The processor may be configured to: support both a first type of UE and a second type of UE having a reduced ability to support a smaller bandwidth than the first type of UE; provide partial system information including the MIB carried by the PBCH signal to the second type of UE by transmitting first system information on the first DL BWP; and provide the remaining system information to the second type of UE by transmitting second system information on the second DL BWP.

[0024] Beneficial Effects

[0025] According to an embodiment of the present disclosure, a user equipment (UE) having a reduced bandwidth capability can perform initial downlink (DL) bandwidth part (BWP) operations and system information acquisition more efficiently.

[0026] The effects of the present disclosure are not limited to those specifically described above, and other effects that the present disclosure can achieve will be more clearly understood from the following detailed description. Description of the Drawings

[0027] Figure 1 Illustrates physical channels used in a Third Generation Partnership Project (3GPP) system as an exemplary wireless communication system, and a general signal transmission method using the physical channels.

[0028] Figure 2 Illustrates a radio frame structure.

[0029] Figure 3 Illustrates a resource grid of a time slot.

[0030] Figure 4 Illustrates a random access procedure.

[0031] Figure 5 Illustrates an example of physical channel mapping.

[0032] Figure 6 Illustrates an exemplary acknowledgement / negative acknowledgement (ACK / NACK) transmission procedure.

[0033] Figure 7 Illustrates an exemplary physical uplink shared channel (PUSCH) transmission procedure.

[0034] Figure 8Illustration of an example of multiplexing control information in PUSCH.

[0035] Figures 9 to 11 Illustration of signal transmission and reception related to the proposal of the present disclosure.

[0036] Figures 12 to 16 It is a diagram for explaining initial DL BWP operation and system information reception related to the proposal of the present disclosure.

[0037] Figure 17 Illustration of signal transmission and reception related to the proposal of the present disclosure.

[0038] Figure 18 and 19 Illustration applied to communication system 1 and wireless device of the present disclosure.

[0039] Figure 20 Illustration applicable to discontinuous reception (DRX) operation of the present disclosure. Detailed implementation mode

[0040] Embodiments of the present disclosure are applicable to various radio access technologies such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). CDMA can be implemented as radio technologies such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented as radio technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rate GSM evolution (EDGE). OFDMA can be implemented as radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and evolved UTRA (E-UTRA). UTRA is part of the universal mobile telecommunications system (UMTS). The 3rd Generation Partnership Project (3GPP) long term evolution (LTE) is part of the evolved UMTS (E-UMTS) using E-UTRA, and LTE-Advanced (A) is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A.

[0041] As more and more communication devices require greater communication capacity, enhanced mobile broadband communication is needed relative to traditional radio access technologies (RATs). Additionally, massive machine-type communication (MTC), which can provide various services anytime and anywhere by connecting multiple devices and objects, is another important issue to be considered in next-generation communication. The design of communication systems for services / UEs that are sensitive to reliability and latency is also being discussed. Therefore, the introduction of a new radio access technology that takes into account enhanced mobile broadband communication (eMBB), massive MTC, and ultra-reliable low-latency communication (URLLC) is being discussed. In this disclosure, for simplicity, this technology will be referred to as NR (New Radio or New RAT).

[0042] For clarity, 3GPP NR is mainly described, but the technical concept of this disclosure is not limited thereto. LTE refers to the technology after Release 8 of 3GPP TS 36.xxx. Specifically, the LTE technology after Release 10 of 3GPP TS 36.xxx is called LTE-A, and the LTE technology after Release 13 of 3GPP TS 36.xxx is called LTE-A pro. 3GPP NR refers to the technology after Release 15 of TS 38.xxx. LTE / NR can be referred to as the 3GPP system. In this document, "xxx" represents the detailed number of the specification. LTE / NR can be collectively referred to as the 3GPP system.

[0043] Details of the background, terms, abbreviations, etc. used in this document can be found in the documents published before this disclosure. For example, this disclosure can be supported by the following documents:

[0044] 3GPP LTE

[0045] - 36.211: Physical Channels and Modulation

[0046] - 36.212: Multiplexing and Channel Coding

[0047] - 36.213: Physical Layer Procedures

[0048] - 36.300: General Description

[0049] - 36.321: Medium Access Control (MAC)

[0050] - 36.331: Radio Resource Control (RRC)

[0051] 3GPP NR

[0052] - 38.211: Physical Channels and Modulation

[0053] - 38.212: Multiplexing and Channel Coding

[0054] -38.213: Physical layer procedures for control

[0055] -38.214: Physical layer procedures for data

[0056] -38.300: General description of NR and NG-RAN

[0057] -38.321: Medium Access Control (MAC)

[0058] -38.331: Radio Resource Control (RRC) protocol specification

[0059] Technical terms used in this document

[0060] -PDCCH: Physical Downlink Control Channel

[0061] -PDSCH: Physical Downlink Shared Channel

[0062] -PUSCH: Physical Uplink Shared Channel

[0063] -CSI: Channel State Information

[0064] -RRM: Radio Resource Management

[0065] -RLM: Radio Link Monitoring

[0066] -DCI: Downlink Control Information

[0067] -CAP: Channel Access Procedure

[0068] -Ucell: Unauthorized cell

[0069] -PCell: Primary cell

[0070] -PSCell: Primary SCG cell

[0071] -TBS: Transport Block Size

[0072] -SLIV: Start and Length Indicator Value (SLIV is a field that indicates the start symbol index and the number of symbols in a time slot for PDSCH and / or PUSCH, and the SLIV is carried on the PDCCH that schedules the corresponding PDSCH and / or PUSCH.)

[0073] - BWP: Bandwidth Part (A BWP can consist of contiguous resource blocks (RBs) in the frequency domain and can correspond to a parameter set (e.g., subcarrier spacing, cyclic prefix (CP) length, slot / micro-slot duration, etc.). Additionally, multiple BWPs can be configured on a carrier (the number of BWPs per carrier can be restricted), but the number of active BWPs in each carrier can be restricted (e.g., one).)

[0074] - CORESET: Control Resource Set (A CORESET refers to the time-frequency resource region capable of transmitting PDCCH, and the number of CORESETs per BWP can be restricted.)

[0075] - REG: Resource Element Group

[0076] - SFI: Slot Format Indicator (An SFI is an indicator that indicates the DL / UL direction at the symbol level in a specific slot, and the SFI is transmitted on the group common PDCCH.)

[0077] - COT: Channel Occupancy Time

[0078] - SPS: Semi-Persistent Scheduling

[0079] - PLMN ID: Public Land Mobile Network Identifier

[0080] - RACH: Random Access Channel

[0081] - RAR: Random Access Response

[0082] - Msg3: The message sent on the UL-SCH, containing the C-RNTI MAC CE or CCCH SDU, submitted from the upper layer and associated with the UE contention resolution identity, as part of the random access procedure.

[0083] - Special Cell: For dual connectivity operation, the term special cell refers to the PCell of the MCG or the PSCell of the SCG, depending on whether the MAC entity is associated with the MCG or the SCG respectively. Otherwise, the term special cell refers to the PCell. The special cell supports PUCCH transmission and contention-based random access and is always active.

[0084] - Serving Cell: PCell, PSCell or SCell

[0085] In the present disclosure, the terms "set / setting" may be replaced with "configure / configuration", and the two may be used interchangeably. In addition, conditional expressions (e.g., "if", "in this case", or "when") may be replaced with "based on" or "in the case / status of". In addition, the operations or software / hardware (SW / HW) configurations of a user equipment (UE) / base station (BS) may be derived / understood based on the satisfaction of corresponding conditions. When the process on the receiving (or transmitting) side can be derived / understood from the process on the transmitting (or receiving) side in signal transmission / reception between wireless communication devices (e.g., BS and UE), its description may be omitted. For example, signal determination / generation / encoding / transmission on the transmitting side may be understood as signal monitoring reception / decoding / determination on the receiving side. In addition, when it is said that the UE performs (or does not perform) a specific operation, this may also be interpreted as the BS expecting / assuming (or not expecting / assuming) the UE to perform the specific operation. When it is said that the BS performs (or does not perform) a specific operation, this may also be interpreted as the UE expecting / assuming (or not expecting / assuming) the BS to perform the specific operation. In the following description, for ease of description, sections, embodiments, examples, options, methods, schemes, proposals, etc. are distinguished from each other and marked with indices, which does not mean that each of them necessarily constitutes an independent disclosure or that each of them can only be implemented separately. Unless explicitly contradictory to each other, it can be derived / understood that at least some of the sections, embodiments, examples, options, methods, schemes, proposals, etc. can be implemented in combination or can be omitted.

[0086] In a wireless communication system, a user equipment (UE) receives information from a base station (BS) via a downlink (DL) and transmits information to the BS via an uplink (UL). The information transmitted and received by the BS and the UE includes data and various control information, and various physical channels are included according to the type / usage of the information transmitted and received by the UE and the BS.

[0087] Figure 1 Illustrates the physical channels used in the 3GPP NR system and the general signal transmission method using them.

[0088] When the UE is powered on again from a power-off state or enters a new cell, in step S101, the UE performs an initial cell search process (e.g., establishing synchronization with the BS). To this end, the UE receives a synchronization signal block (SSB) from the BS. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The UE establishes synchronization with the BS based on the PSS / SSS and obtains information such as a cell identifier (ID). The UE may obtain broadcast information in the cell based on the PBCH. The UE may receive a DL reference signal (RS) during the initial cell search process to monitor the DL channel state.

[0089] The SSB consists of four consecutive OFDM symbols, and each symbol carries PSS, PBCH, SSS / PBCH, or PBCH. Each of the PSS and SSS consists of one OFDM symbol multiplied by 127 subcarriers, and the PBCH consists of three OFDM symbols multiplied by 576 subcarriers. The PBCH is encoded / decoded based on a polar code and modulated / demodulated according to quadrature phase shift keying (QPSK). The PBCH in the OFDM symbol consists of data resource elements (REs) to which the complex modulation values of the PBCH are mapped and demodulation reference signal (DMRS) REs to which the DMRS for the PBCH is mapped. Three DMRS REs are configured for each RB in the OFDM symbol, and three data REs are configured between the DMRS REs.

[0090] The PSS can be used to detect the cell ID within a cell ID group, and the SSS can be used to detect the cell ID group. The PBCH can be used to detect the SSB (time) index and the half-frame. There are 336 cell ID groups, and each cell ID group includes three cell IDs. Therefore, there are a total of 1008 cell IDs.

[0091] The SSB is transmitted periodically with an SSB period. The default SSB period assumed by the UE in the initial cell search is defined as 20 ms. After cell access, the SSB period can be set by the network (e.g., the BS) to one of {5 ms, 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms}. An SSB burst set can be configured at the start of the SSB period. The SSB burst set can be set to a time window of 5 ms (i.e., a half-frame), and the SSB can be repeatedly transmitted up to L times within the SS burst set. The maximum number L of SSB transmissions can be given depending on the carrier frequency band as follows. One time slot includes up to two SSBs.

[0092] - For a frequency range of up to 3 GHz, L = 4

[0093] - For a frequency range from 3 GHz to 6 GHz, L = 8

[0094] - For a frequency range from 6 GHz to 52.6 GHz, L = 64

[0095] The time-domain position of the candidate SSB in the SS burst set can be defined depending on the subcarrier spacing. The time-domain position of the candidate SSB is indexed in chronological order from 0 to L - 1 within the SSB burst set (i.e., the half-frame).

[0096] Multiple SSBs can be transmitted within the frequency span of a carrier. Each SSB may not need to have a unique physical layer cell identifier, but different SSBs may have different physical layer cell identifiers.

[0097] The UE can obtain DL synchronization by detecting the SSB. The UE can identify the structure of the SSB burst set based on the detected SSB (time) index, and thus the UE can detect symbol / slot / half-frame boundaries. The frame / half-frame number to which the detected SSB belongs can be identified based on the system frame number (SFN) information and the half-frame indication information.

[0098] Specifically, the UE can obtain the 10-bit SFN of the frame to which the PBCH belongs from the PBCH. Then, the UE can obtain 1-bit half-frame indication information. For example, when the UE detects a PBCH in which the half-frame indication bit is set to 0, the UE can determine that the SSB to which the PBCH belongs is included in the first half-frame of the frame. When the UE detects a PBCH in which the half-frame indication bit is set to 1, the UE can determine that the SSB to which the PBCH belongs is included in the second half-frame of the frame. Finally, the UE can obtain the SSB index of the SSB to which the PBCH belongs based on the PBCH payload carried by the PBCH and the DMRS sequence.

[0099] After initial cell search, in step S102, the UE can obtain more specific system information by receiving the physical downlink control channel (PDCCH) and receiving the physical downlink shared channel (PDSCH) based on the information of the PDCCH.

[0100] System information (SI) is divided into a master information block (MIB) and multiple system information blocks (SIBs). The SI other than the MIB can be referred to as the remaining minimum system information (RMSI). Details will be described below.

[0101] - The MIB includes information / parameters of the PDCCH for monitoring the PDSCH that schedules the System Information Block 1 (SIB1), and the MIB is sent by the BS on the PBCH of the SSB. For example, the UE can check based on the MIB whether there is a CORESET for the Type0-PDCCH common search space. The Type0-PDCCH common search space is a type of PDCCH search space used to send the PDCCH that schedules the SI message. If there is a Type0-PDCCH common search space, the UE can determine based on the information in the MIB (e.g., pdcch-ConfigSIB1) (i) the multiple consecutive RBs and one or more consecutive symbols included in the CORESET, and (ii) the PDCCH occasion (e.g., the time-domain position for PDCCH reception). If the Type0-PDCCH common search space does not exist, pdcch-ConfigSIB1 provides information about the frequency position where the SSB / SIB1 exists and information about the frequency range where the SSB / SIB1 does not exist.

[0102] - SIB1 includes information related to the availability and scheduling (e.g., transmission periodicity, SI window size, etc.) of the remaining SIBs (hereinafter referred to as SIBx, where x is an integer greater than or equal to 2). For example, SIB1 can indicate whether SIBx is broadcast periodically or provided on demand in response to a UE request. When SIBx is provided on demand, SIB1 can include the information necessary for the UE to send an SI request. SIB1 is sent on the PDSCH, and the PDCCH that schedules SIB1 is sent in the Type0-PDCCH common search space. That is, SIB1 is sent on the PDSCH indicated by the PDCCH.

[0103] - SIBx is included in the SI message and sent on the PDSCH. Each SI message is sent within a time window that appears periodically (i.e., the SI window).

[0104] In steps S103 to S106, the UE can perform a random access procedure to access the BS. For random access, the UE can send a preamble to the BS on the Physical Random Access Channel (PRACH) (S103) and receive a response message to the preamble on the PDCCH and the PDSCH corresponding to the PDCCH (S104). In the case of contention-based random access, the UE can perform a contention resolution process by further sending the PRACH (S105) and receiving the PDCCH and the PDSCH corresponding to the PDCCH (S106).

[0105] After the foregoing process, the UE may receive PDCCH / PDSCH (S107) and transmit a Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUCCH) (S108), as a general downlink / uplink signal transmission process. Control information sent from the UE to the BS is referred to as Uplink Control Information (UCI). UCI includes Hybrid Automatic Repeat reQuest and Acknowledgment / Negative Acknowledgment (HARQ-ACK / NACK), Scheduling Request (SR), Channel State Information (CSI), etc. CSI includes Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), Rank Indicator (RI), etc. Although UCI is usually sent on the PUCCH, when it is necessary to transmit control information and traffic data simultaneously, UCI may be sent on the PUSCH. Additionally, UCI may be sent non-periodically via the PUSCH according to a request / command from the network.

[0106] Figure 2 The figure shows the radio frame structure. In NR, uplink transmission and downlink transmission are configured with frames. Each radio frame has a length of 10 ms and is divided into two 5 ms half-frames (HF). Each half-frame is divided into five 1 ms sub-frames (SF). A sub-frame is divided into one or more time slots, and the number of time slots in a sub-frame depends on the Subcarrier Spacing (SCS). According to the Cyclic Prefix (CP), each time slot includes 12 or 14 Orthogonal Frequency Division Multiplexing (OFDM) symbols. When normal CP is used, each time slot includes 14 OFDM symbols. When extended CP is used, each time slot includes 12 OFDM symbols.

[0107] Table 1 exemplarily shows that the number of symbols per time slot, the number of time slots per frame, and the number of time slots per sub-frame vary according to the SCS when normal CP is used.

[0108] [Table 1]

[0109] SCS (15 * 2^u) <![CDATA[N slot symb > <![CDATA[N frame,u slot > <![CDATA[N subframe,u slot > 15 KHz (u = 0) 14 10 1 30 KHz (u = 1) 14 20 2 60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14 160 16

[0110] *N slot symb : Number of symbols in a time slot

[0111] *N frame,u slot : Number of time slots in a frame

[0112] *N subframe,u slot : Number of time slots in a sub-frame

[0113] Table 2 shows that the number of symbols per time slot, the number of time slots per frame, and the number of time slots per sub-frame vary according to the SCS when extended CP is used.

[0114] [Table 2]

[0115] SCS (15 * 2^u) <![CDATA[N slot symb > <![CDATA[N frame,u slot > <![CDATA[N subframe,u slot > 60 KHz (u = 2) 12 40 4

[0116] The structure of a frame is merely an example. The number of sub - frames, time slots, and symbols in a frame can vary.

[0117] In the NR system, OFDM parameter sets (e.g., SCS) can be configured differently for multiple cells aggregated for one UE.

[0118] Therefore, the (absolute time) duration of a time resource (e.g., SF, time slot, or TTI) composed of the same number of symbols (referred to as a time unit (TU) for simplicity) can be configured differently among the aggregated cells. Here, a symbol can include an OFDM symbol (or CP - OFDM symbol) and an SC - FDMA symbol (or discrete Fourier transform - spread - OFDM (DFT - s - OFDM) symbol).

[0119] Figure 3 A resource grid showing a time slot is presented. A time slot includes multiple symbols in the time domain. For example, when using normal CP, a time slot includes 14 symbols. However, when using extended CP, a time slot includes 12 symbols. A carrier includes multiple sub - carriers in the frequency domain. A resource block (RB) is defined as multiple consecutive sub - carriers in the frequency domain (e.g., 12 consecutive sub - carriers). A bandwidth part (BWP) can be defined as multiple consecutive physical resource blocks (PRBs) in the frequency domain and corresponds to a single parameter set (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., five) BWPs. Data communication can be performed through the enabled BWP, and only one BWP can be enabled for one UE. In the resource grid, each element is called a resource element (RE), and one complex symbol can be mapped to each RE.

[0120] Bandwidth part (BWP)

[0121] The NR system can support frequencies up to 400 MHz for each carrier. The network can indicate to the UE to operate only in a part of the bandwidth of such a wide - band carrier rather than the entire bandwidth. The part of the bandwidth is called BWP. BWP refers to a subset of consecutive common RBs defined by the parameter set in the BWP of a carrier in the frequency domain, and one parameter set (e.g., SCS, CP length, time slot / micro - time slot duration, etc.) can be configured.

[0122] Activation / deactivation of DL / UL BWP or BWP switching can be performed according to network signaling and / or timers (e.g., L1 signaling corresponding to physical layer control signals, MAC control elements corresponding to MAC layer control signals, RRC signaling, etc.). When performing initial access or before setting up an RRC connection, the UE may not receive any DL / UL BWP configuration. The DL / UL BWP assumed by the UE in such a case is called the initial active DL / UL BWP.

[0123] Regarding the initial DL BWP, the following UE operations are defined in the 3GPP NR specification.

[0124] * For the DL BWP, if the UE is not provided with searchSpaceSIB1 for the Type0-PDCCH CSS set via PDCCH-ConfigCommon, the UE does not monitor PDCCH candidates for the Type0-PDCCH CSS set on the DL BWP. The Type0-PDCCH CSS set is defined by the CCE aggregation level and the number of PDCCH candidates per CCE aggregation level. If the active DL BWP and the initial DL BWP have the same SCS and the same CP length and the active DL BWP includes all RBs with a CORESET having an index of 0, or the active DL BWP is the initial DL BWP, the CORESET configured for the Type0-PDCCH CSS set has a CORESET index of 0, and the Type0-PDCCH CSS set has a search space set index of 0.

[0125] * The UE configured to operate in a bandwidth part (BWP) of a serving cell is configured by a higher layer for the serving cell with a set (DL BWP set) of up to four bandwidth parts (BWPs) to be received by the UE in the DL bandwidth (configured via the parameter BWP-Downlink or via the parameter initialDownlinkBWP with a parameter set configured by BWP-DownlinkCommon and BWP-DownlinkDedicated) and a set (UL BWP set) of up to four bandwidth parts (BWPs) to be transmitted by the UE in the UL bandwidth (configured via the parameter BWP-Uplink or via the parameter initialUplinkBWP with a parameter set configured by BWP-UplinkCommon and BWP-UplinkDedicated).

[0126] *If no initialDownlinkBWP is provided for the UE, the initial DL BWP is defined by the position and number of consecutive PRBs starting from the PRB with the lowest index among the PRBs of the CORESET for the Type0-PDCCH CSS set and ending at the PRB with the highest index, and the SCS and cyclic prefix used for PDCCH reception in the CORESET for the Type0-PDCCH CSS set; otherwise, the initial DL BWP is provided by initialDownlinkBWP. For operation on the primary cell or secondary cell, the initial UL BWP is provided for the UE by initialUplinkBWP. If the UE is configured with a secondary UL carrier, the initial UL BWP can be provided for the UE on the secondary UL carrier by initialUplinkBWP.

[0127] *If controlResourceSetZero and searchSpaceZero are provided for the UE in PDCCH-ConfigSIB1 or PDCCH-ConfigCommon, the UE determines the CORESET for the search space set from controlResourcesetZero and determines the corresponding PDCCH monitoring occasion. If the active DL BWP is not the initial DL BWP, the UE determines the PDCCH monitoring occasion for the search space set only when the CORESET bandwidth is within the active DL BWP and the active DL BWP has the same SCS configuration and the same cyclic prefix as the initial DL BWP.

[0128] *For the serving cell, the default DL BWP among the configured DL BWPs can be provided for the UE by defaultDownlinkBWP-Id. If no default DL BWP is provided for the UE by defaultDownlinkBWP-Id, the default DL BWP is the initial DL BWP.

[0129] Figure 4 The figure illustrates an exemplary normal random access procedure. Specifically, Figure 4 shows the contention-based random access procedure of the UE, which is performed in four steps.

[0130] First, the UE may send a Message 1 (Msg1) including a random access preamble on the PRACH (see Figure 4 (1701) of (a)).

[0131] It can support random access preamble sequences with different lengths. The long sequence length of 839 can be applied to SCSs of 1.25 and 5 kHz, and the short sequence length of 139 can be applied to SCSs of 15, 30, 60, and 120 kHz.

[0132] Multiple preamble formats can be defined by one or more RACH OFDM symbols and different CPs (and / or guard times). The RACH configuration for a cell can be included in the SI regarding the cell and provided to the UE. The RACH configuration can include information such as the SCS of the PRACH, available preambles, preamble formats, etc. The RACH configuration can include information about the association between the SSB and the RACH (time-frequency) resources. The UE sends a random access preamble on the RACH time-frequency resources associated with the detected or selected SSB.

[0133] The threshold of the SSB for RACH resource association can be configured by the network, and the RACH preamble can be sent or retransmitted based on the SSB, where the reference signal received power (RSRP) measured based on the SSB meets the threshold. For example, the UE can select an SSB from among the SSBs that meet the threshold and send or retransmit the RACH preamble based on the RACH resources associated with the selected SSB.

[0134] Upon receiving a random access preamble from the UE, the BS can send message 2 (Msg2) corresponding to the random access response (RAR) message (see Figure 4 (1703) of (a)). The PDCCH scheduling the PDSCH carrying the RAR can be CRC masked with the random access (RA) radio network temporary identifier (RNTI) (RA-RNTI) and then sent. When the UE detects the PDCCH masked by the RA-RNTI, the RAR can be obtained from the PDSCH scheduled by the DCI carried by the PDCCH. The UE can check whether the RAR includes a response to the preamble sent by the UE, i.e., the RAR information of Msg1. The presence or absence of the RAR information in response to Msg1 sent by the UE can be determined depending on whether there is a random access preamble ID for the preamble sent by the UE. If there is no response to Msg1, the UE can retransmit the RACH preamble a predetermined number of times while performing power ramping. The UE can calculate the PRACH transmit power for retransmitting the preamble based on the most recent path loss and the power ramping counter.

[0135] The RAR information transmitted on the PDSCH may include timing advance (TA) information for UL synchronization, an initial UL grant, and a temporary cell-RNTI (C-RNTI). The TA information may be used to control the UL signal transmission timing. The UE may transmit a UL signal on the UL shared channel as Message 3 (Msg3) of the random access procedure based on the RAR information (see Figure 4 (1705 of (a)). Msg3 may include an RRC connection request and a UE identifier. In response to Msg3, the network may send Message 4 (Msg4), which may be regarded as a contention resolution message on the DL (see Figure 4 (1707 of (a)). Upon receiving Msg4, the UE may enter the RRC_CONNECTED state.

[0136] On the other hand, when the UE is switched to another cell or BS or when it is requested by the BS, a contention-free random access procedure may be performed. In the contention-free random access procedure, a preamble to be used by the UE (hereinafter referred to as a dedicated random access preamble) is allocated by the BS. Information about the dedicated random access preamble may be included in an RRC message (e.g., a handover command) or provided to the UE via a PDCCH command. When initiating the random access procedure, the UE may send the dedicated random access preamble to the BS. When the UE receives an RAR from the BS, the random access procedure is completed.

[0137] As described above, the UL grant in the RAR may schedule PUSCH transmission for the UE. The PUSCH carrying the initial UL transmission based on the UL grant in the RAR is referred to as the Msg3 PUSCH. The content of the RAR UL grant may start at the MSB and end at the LSB, and the content may be given as shown in Table 3.

[0138] [Table 3]

[0139] RAR UL grant field Number of bits Frequency hopping flag 1 Msg3 PUCCH frequency resource allocation 12 Msg3 PUSCH time resource allocation 4 Modulation and coding scheme (MCS) 4 Transmit power control (TPC) for Msg3 PUSCH 3 CSI request 1

[0140] Figure 5 An exemplary mapping of physical channels in the illustrated time slot. The PDCCH may be transmitted in the DL control region, and the PDSCH may be transmitted in the DL data region. The PUCCH may be transmitted in the UL control region, and the PUSCH may be transmitted in the UL data region. The guard period (GP) provides a time gap for the transmission mode to reception mode or reception mode to transmission mode switching at the BS and the UE. Some symbols at the DL to UL handover in a subframe may be configured as the GP.

[0141] Each physical channel will be described in more detail below.

[0142] The PDCCH delivers DCI. For example, the PDCCH (i.e., DCI) can carry information about the transmission format and resource allocation of the DL shared channel (DL-SCH), the resource allocation information of the uplink shared channel (UL-SCH), the paging information about the paging channel (PCH), the system information about the DL-SCH, the information about the resource allocation of higher layer control messages (such as the RAR sent on the PDSCH), the transmit power control command, the information about the activation / release of the configured scheduling, etc. The DCI includes a cyclic redundancy check (CRC). The CRC is masked with various identifiers (IDs) (e.g., radio network temporary identifier (RNTI)) according to the owner or use of the PDCCH. For example, if the PDCCH is for a specific UE, the CRC is masked with the UE ID (e.g., cell RNTI (C-RNTI)). If the PDCCH is for a paging message, the CRC is masked with the paging RNTI (P-RNTI). If the PDCCH is for system information (e.g., system information block (SIB)), the CRC is masked with the system information RNTI (SI-RNTI). When the PDCCH is for the RAR, the CRC is masked with the random access RNTI (RA-RNTI).

[0143] The PDCCH includes 1, 2, 4, 8, or 16 control channel elements (CCEs) according to its aggregation level (AL). The CCE is a logical allocation unit for providing a specific code rate for the PDCCH according to the radio channel state. The CCE includes 6 resource element groups (REGs), and each REG is defined by one OFDM symbol multiplied by one (P)RB. The PDCCH is sent in a control resource set (CORESET). The CORESET is defined as a set of REGs with a given parameter set (e.g., SCS, CP length, etc.). Multiple CORESETs for one UE can overlap with each other in the time domain / frequency domain. The CORESET can be configured by system information (e.g., master information block (MIB)) or UE-specific higher layer signaling (e.g., radio resource control (RRC) signaling). Specifically, the number of RBs and the number of symbols (up to 3) in the CORESET can be configured by higher layer signaling.

[0144] For PDCCH reception / detection, the UE monitors PDCCH candidates. A PDCCH candidate is a CCE that the UE should monitor to detect the PDCCH. According to the AL, each PDCCH candidate is defined as 1, 2, 4, 8, or 16 CCEs. Monitoring includes (blind) decoding of PDCCH candidates. The set of PDCCH candidates decoded by the UE is defined as the PDCCH search space (SS). The SS can be a common search space (CSS) or a UE-specific search space (USS). The UE can obtain DCI by monitoring PDCCH candidates in one or more SSs configured by the MIB or higher-layer signaling. Each CORESET is associated with one or more SSs, and each SS is associated with a CORESET. The SS can be defined based on the following parameters.

[0145] - controlResourceSetId: The CORESET associated with the SS.

[0146] - monitoringSlotPeriodicityAndOffset: The PDCCH monitoring periodicity (in units of slots) and the PDCCH monitoring offset (in units of slots).

[0147] - monitoringSymbolsWithinSlot: The PDCCH monitoring symbols within a slot (e.g., the first symbol of the CORESET).

[0148] - nrofCandidates: The number of PDCCH candidates for each AL = {1, 2, 4, 8, 16} (one of 0, 1, 2, 3, 4, 5, 6, and 8).

[0149] * Where the occasion (e.g., time / frequency resource) when the UE is going to monitor PDCCH candidates is defined as the PDCCH (monitoring) occasion. One or more PDCCH (monitoring) occasions can be configured in a slot.

[0150] Table 4 shows the characteristics of each SS.

[0151] [Table 4]

[0152]

[0153] Table 5 shows the DCI formats transmitted on the PDCCH.

[0154] [Table 5]

[0155]

[0156]

[0157] DCI format 0_0 can be used to schedule TB (or TB-level) based PUSCH, and DCI format 0_1 can be used to schedule TB (or TB-level) based PUSCH or codeblock group (CBG) (or CBG-level) based PUSCH. DCI format 1_0 can be used to schedule TB (or TB-level) based PDSCH, and DCI format 1_1 can be used to schedule TB (or TB-level) based PDSCH or CBG (or CBG-level) based PDSCH (DL grant DCI). DCI formats 0_0 / 0_1 can be referred to as UL grant DCI or UL scheduling information, and DCI formats 1_0 / 1_1 can be referred to as DL grant DCI or DL scheduling information. DCI format 2_0 is used to deliver dynamic time slot format information (e.g., dynamic time slot format indicator (SFI)) to the UE, and DCI format 2_1 is used to deliver DL preemption information to the UE. DCI format 2_0 and / or DCI format 2_1 can be delivered on the group common PDCCH to a corresponding group of UEs, which is the PDCCH for a group of UEs.

[0158] DCI formats 0_0 and 1_0 can be referred to as fallback DCI formats, while DCI formats 0_1 and 1_1 can be referred to as non-fallback DCI formats. In the fallback DCI formats, the DCI size / field configuration remains the same regardless of the UE configuration. In contrast, the DCI size / field configuration varies depending on the UE configuration in the non-fallback DCI formats.

[0159] The PDSCH carries DL data (e.g., DL shared channel transport block (DL-SCH TB)) and uses modulation schemes such as quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (16QAM), 64QAM, or 256QAM. The TB is encoded into codewords. The PDSCH can carry up to two codewords. Scrambling and modulation mapping can be performed on a codeword basis, and the modulation symbols generated from each codeword can be mapped to one or more layers. Each layer together with the demodulation reference signal (DMRS) is mapped to resources, and the OFDM symbol signal is generated from the mapped layers with DMRS and transmitted through the corresponding antenna ports.

[0160] The PUCCH carries uplink control information (UCI). The UCI includes the following information.

[0161] - SR (scheduling request): Information used to request UL-SCH resources.

[0162] - HARQ (Hybrid Automatic Repeat reQuest) - ACK (ACKnowledgment): Response to DL data packets (e.g., codewords) on the PDSCH. The HARQ-ACK indicates whether the DL data packet has been successfully received. In response to a single codeword, a 1-bit HARQ-ACK can be sent. In response to two codewords, a 2-bit HARQ-ACK can be sent. The HARQ-ACK response includes a positive ACK (simply referred to as ACK), a negative ACK (NACK), a Discontinuous Transmission (DTX), or NACK / DTX. The term HARQ-ACK is interchangeable with HARQ ACK / NACK and ACK / NACK.

[0163] - CSI (Channel State Information): Feedback information for DL channels. The feedback information related to Multiple-Input Multiple-Output (MIMO) includes RI and PMI.

[0164] The PUSCH delivers UL data (e.g., UL Shared Channel Transport Block (UL-SCH TB)) and / or UCI based on the CP-OFDM waveform or the DFT-s-OFDM waveform. When the PUSCH is sent in the DFT-s-OFDM waveform, the UE transmits the PUSCH through transform precoding. For example, when transform precoding is not possible (e.g., disabled), the UE is able to transmit the PUSCH in the CP-OFDM waveform, and when transform precoding is possible (e.g., enabled), the UE is able to transmit the PUSCH in the CP-OFDM waveform or the DFT-s-OFDM waveform. The PUSCH transmission can be dynamically scheduled by a UL grant in DCI, or semi-statically scheduled (configured scheduling or configured grant) by higher layer (e.g., RRC) signaling (and / or layer 1 (L1) signaling such as the PDCCH). The PUSCH transmission can be performed in a codebook-based or non-codebook-based manner.

[0165] Initial DL for UE cell access BWP selection and common channel reception

[0166] Generally, a UE needs to support specific UE capabilities to access a cell. For example, to access an LTE cell, the UE needs to be able to receive the MIB and SIBs broadcast by the BS for that cell. Since there are several types of SIBs (e.g., SIB1, SIB2.., SIBx-y, etc.) and the SIBs are sent in multiple PRBs, a UE intending to access an LTE cell needs to have at least the ability to receive a 20 MHz bandwidth.

[0167] To access an NR cell, the UE needs to be able to receive the MIB in the SSB / PBCH transmitted in the initial DL BWP. Even if the UE can receive the SSB / PBCH, based on the cell access information included in SIB1, the UE also needs to check whether the UE is allowed to access the corresponding cell. To this end, the UE can check based on the MIB whether there is a CORESET for the Type0-PDCCH common search space (CSS). If there is a Type0-PDCCH CSS, the UE can determine CORSET#0 and PDCCH occasions based on the information in the MIB (e.g., pdcch-ConfigSIB1). Then, the UE can receive SIB1 through the PDSCH indicated by the PDCCH received on the corresponding PDCCH occasion.

[0168] When the UE receives the SIB, it needs to check various information to determine whether the UE is allowed to access the cell. If the information does not meet some conditions, the UE can set the corresponding cell as a prohibited access cell. For example, the maximum UL channel bandwidth supported by the UE needs to be greater than or equal to the bandwidth of the initial UL BWP, and the maximum DL channel bandwidth supported by the UE needs to be greater than or equal to the bandwidth of the initial DL BWP. If this condition is not met, the UE can set the corresponding cell as a prohibited access cell.

[0169] REL-17 NR is designed to support a new type of UE with reduced capabilities. This type of UE is called an R-terminal or R-UE, which is different from legacy REL-15 UEs.

[0170] Since the UE capabilities of R-UEs are restricted compared to legacy UEs, problems may occur during the cell access process. For example, an R-UE may not be able to receive the MIB in the initial DL BWP of a legacy NR cell. Additionally, even if an R-UE is allowed to receive the MIB, the R-UE may not be able to receive the PDCCH that schedules CORSET#0 or SIB1. Alternatively, the maximum UL channel bandwidth or maximum DL channel bandwidth of the R-UE may not be greater than or equal to the bandwidth of the initial BWP supported by the legacy NR cell. Alternatively, considering the parameter set supported by the initial BWP of the legacy cell, the R-UE may not receive the paging message sent from the BS or may not be able to perform UL RACH transmission for initial access due to the SCS. Due to these problems, from the perspective of the R-UE, normal NR cells may often be set as prohibited access cells.

[0171] For the following reasons, the BS may need to provide a common channel transmission / reception method suitable for the R-UE at the start of the initial access procedure. First, legacy UEs can receive up to four transmissions based on frequency division multiplexing (FDM): paging, MIB, SIB1, and unicast, but the number of channels that the R-UE can receive simultaneously may be reduced due to the limited capabilities of the R-UE. Second, the set of parameters required for user services suitable for the R-UE may be different from the set of parameters accessible to ordinary UEs, and thus the parameter set of the initial BWP of the legacy cell may not be suitable for the R-UE. Third, due to limited RF capabilities, the cell coverage of the R-UE may be reduced compared to that of legacy UEs. Finally, the R-UE may require improved power-saving techniques compared to legacy UEs.

[0172] Accordingly, the present disclosure proposes a method in which, when an R-UE with limited capabilities performs initial access to a wireless network system through a cell, the BS managing the corresponding cell provides an initial DL BWP available to the R-UE. Specifically, the BS may provide two or more initial DL BWPs for the cell, and the UE may select one initial DL BWP from among the multiple initial DL BWPs depending on the capabilities supported by the UE. In addition, the UE may receive the common channel of the cell and then receive system information, a paging message, or an RAR message through the common channel.

[0173] The following operations may be provided so that the UE receives the DL common channel.

[0174] Figure 9 is a diagram for explaining UE operations in an initial DL BWP according to an embodiment of the present disclosure.

[0175] Referring to Figure 9 , the UE may detect a synchronization channel and receive the master information (A05) of the cell. The synchronization channel may correspond to the SSB. The master information may correspond to the MIB.

[0176] The UE may determine whether to configure a second initial DL BWP (A10) compatible with a second type of UE based on the capabilities of the UE.

[0177] Compared to a first type of UE corresponding to a Release 15 NR UE, the second type of UE may have reduced capabilities.

[0178] The second initial DL BWP may be compatible with at least the second type of UE, while the first initial DL BWP may be compatible with at least the first type of UE.

[0179] The second initial DL BWP may provide a smaller number of PRBs than the first initial DL BWP.

[0180] - If the UE's capabilities do not support the first initial DL BWP of the cell, or if the second initial UL BWP is associated with a second type of UE (this association can be indicated by the system information of the cell),

[0181] - The UE can switch to the second initial DL BWP (A15) to receive the common channel (A20) carrying common information.

[0182] The UE can activate the second initial DL BWP (A15) while deactivating the first initial DL BWP.

[0183] For the UE, the priority of the second initial DL BWP can be higher than that of the first initial DL BWP.

[0184] The common channel or common information can be prioritized over other channels or other information.

[0185] - The UE can switch back to the first initial DL BWP to receive the synchronization channel and / or the master information (e.g., perform idle measurements). The UE can activate the first initial DL BWP while deactivating the second initial DL BWP.

[0186] - The UE can access the cell based on the common information.

[0187] The UE can perform RF retuning to switch to one of the BWPs.

[0188] The common channel can correspond to one of the PDCCH, PDSCH, and PBCH.

[0189] The common information can correspond to one of the system information, system information modification, short message, paging message, warning message, and warning message indicator.

[0190] Hereinafter, the second initial DL BWP is referred to as the initial DL R-BWP, and the first initial DL BWP is referred to as the (legacy) initial DL BWP. Additionally, the second type of UE is referred to as the R-terminal, R-UE, or (in this disclosure) UE, and the first type of UE is referred to as the legacy UE or traditional UE.

[0191] 1) SI transmission side (e.g., BS):

[0192] In an example of the present disclosure, if an R-UE cannot receive a legacy SIB1 transmission, if the legacy SIB1 is not relevant to the R-UE, or if the R-UE needs to receive additional R-UE specific information in addition to the legacy SIB1 information, the R-UE may receive a new SIB1. For convenience, the SIB1 that can be received by the R-UE is referred to as R-SIB1. The R-SIB1 may include all or part of the configuration information included in the legacy SIB1, and the R-SIB1 may also include configuration information dedicated to the R-UE. The legacy UE may not receive the R-SIB1.

[0193] In this case, from the perspective of the BS, a cell needs to operate two types of SIB1 simultaneously: SIB1 and R-SIB1. One type of MIB can be mapped to the two types of SIB1. Alternatively, the MIB can be mapped to the legacy SIB1, and the legacy SIB1 can be mapped to the R-SIB1. Here, mapping may mean a logical mapping between SIBs that are related / linked to each other. In addition, the legacy SIB1 and the R-SIB1 may include scheduling information (e.g., schedulingInfoList) that notifies whether other SIBs are broadcast and their transmission periods.

[0194] A cell may operate the legacy SIBx and the new SIBx simultaneously. The new SIBx may include R-UE specific information or information that is not relevant to the legacy UE, which is referred to as R-SIBx. For example, in the case of SIB3 that includes intra-frequency cell reselection information, a cell may transmit the legacy SIB3 and the R-SIB3 together. In this case, the legacy SIB3 can be used by the legacy UE to perform cell reselection, and the R-SIB3 can be used by the R-UE to perform cell reselection. If the legacy SIBx does not include R-UE specific information, or if the R-UE specific information is only included in the R-SIBx, the scheduling information for the R-SIB1 may notify whether the R-SIBx is broadcast and its transmission period, and the scheduling information for the legacy SIB1 may notify whether the legacy SIBx is broadcast and its transmission period.

[0195] On the other hand, the legacy SIBx may also include information related to both the R-UE and the legacy UE. In this case, the scheduling information for the legacy SIB1 and the scheduling information for the R-SIB1 may schedule the legacy SIBx together. For example, in the case where SIB6 or SIB7 broadcasts a public warning message, the scheduling information for the legacy SIB1 and the scheduling information for the R-SIB1 may schedule SIB6 or SIB7 together. Alternatively, the scheduling information for the legacy SIB1 and the scheduling information for the R-SIB1 may schedule the R-SIBx together.

[0196] 2) SI receiving side (e.g., UE):

[0197] [Proposal #1] When selecting the initial cell, the R-UE can use the legacy initial DL BWP until it receives at least the MIB from the serving cell. After receiving the MIB, the R-UE can switch to the initial DL R-BWP and perform system information, paging, and random access operations. Figure 10 Figure 12 Figure 13

[0198] Figure 13 The figure illustrates an exemplary initial access procedure according to Proposal #1.

[0199] For example, the R-UE may receive the MIB (B05) from the selected cell during the initial cell selection process, measurement process, and / or mobility process such as handover.

[0200] The R-UE may determine the CSS and / or CORESET0 (B10) for the R-UE.

[0201] For example, the R-UE may check, based on the received MIB, whether there is a CORESET for the Type0-PDCCH CSS, i.e., CORESET0. The CORESET0 for the Type0-PDCCH CSS for the R-UE may be configured commonly for both legacy UEs and the R-UE (e.g., at the timing t1 in Figure 10 the BWP switches to the R-BWP), or the CORESET0 for the Type0-PDCCH CSS for the R-UE may be configured only for the R-UE (e.g., at the timing t1 in [Proposal #2] When selecting the initial cell, the R-UE can perform the legacy initial DL BWP until it receives at least the PDCCH for SIB1 from the serving cell. After receiving the PDCCH, the R-UE can switch to the initial DL R-BWP and perform system information, paging, and random access operations. the BWP switches to the R-BWP). For example, if the R-UE supports the legacy CORESET0, the legacy CORESET0 and the legacy Type0-PDCCH CSS may be defined / used as the CORESET0 for the R-UE and the Type0-PDCCH CSS for the R-UE, respectively. In this case, the R-UE may receive the PDCCH in the legacy CORESET0 / CSS. On the other hand, if the R-UE cannot support the legacy CORESET0, or if the R-UE cannot use the legacy CORESET0, the CORESET0 for the R-UE and the Type0-PDCCH CSS for the R-UE may be defined / configured / used independently of the legacy CORESET0 and the legacy Type0-PDCCH CSS. In this case, the R-UE may receive the PDCCH in the CORESET0 / CSS dedicated to the R-UE. A part or all of the Type0-PDCCH CSS for the legacy UE may be combined with an additional Type0-PDCCH CSS dedicated to the R-UE to configure the CSS for the R-UE.

[0202] For example, when the CSS for the R-UE exists in the initial cell selection process, measurement process, and / or mobility processes such as handover, the UE can determine (i) a plurality of consecutive RBs and one or more consecutive symbols that are included in CORESET0; (ii) the PDCCH occasion (i.e., the time-domain position for PDCCH reception) based on the information in the SSB or MIB (e.g., pdcch-ConfigSIB1). For example, the CORESET0 determined by pdcch-ConfigSIB1 can be the CORESET0 for legacy UEs, and the CORESET0 for the R-UE can be configured by an offset from the CORESET0 for legacy UEs (e.g., Figure 11 (b)). The CORESET0 for the R-UE can be determined such that the position of the CORESET0 for legacy UEs is displaced by either or both of a time-domain offset or a frequency-domain offset. For example, the corresponding frequency-domain offset can be configured at the RB and / or RE level, and in this case, the RB-level offset can vary for each frequency band. The frequency-domain offset can be defined as the offset between the first or last RB of the SSB / PBCH and the first RB of the CORESET0 for the R-UE, or the frequency-domain offset can be defined as the offset between the first or last RB of the legacy CORESET0 and the first or last RB of the CORESET0 for the R-UE. On the other hand, the time-domain offset can be set to the number of symbols. When the offset is zero, the CORESET0 for the R-UE can be defined in the same symbol as the SSB / PBCH or the legacy CORESET0. When the offset is non-zero, the CORESET0 for the R-UE can be configured to be located before or after the time-domain offset from the SSB / PBCH or the legacy CORESET0. The value or range of the offset can be signaled by the network (e.g., indicated by the reserved bits of the MIB), or the offset can have a fixed value. As an example where the value or range of the offset is fixed, a fixed offset value or fixed offset range can be predefined / preconfigured for each frequency band.

[0203] For example, when there is no CSS for the R-UE during the initial cell selection process, measurement process, and / or mobility processes such as handover, the PBCH payload (e.g., other information in pdcch-ConfigSIB1 or MIB) can provide (i) information about the frequency positions where the SSB / SIB1 for legacy UEs or the SSB / R-SIB1 for R-UEs exist; and / or (ii) information about the frequency ranges where the SSB / SIB1 for legacy UEs or the SSB / R-SIB1 for R-UEs do not exist (e.g., for UE redirection). For example, the BS can indicate the provided information based on the MIB (e.g., using reserved bits of the MIB): whether the information (i) and / or (ii) is for legacy UEs or for R-UEs. For example, the BS can use the MIB (e.g., reserved bits of the MIB) to notify the R-UE whether it needs to measure the corresponding resources for cell reselection, mobility, or automatic neighbor relation (ANR). The R-UE can detect the frequency positions of the SSB / R-SIB1 of the R-UE based on the provided information: information (i) and / or (ii). After receiving the MIB, the R-UE can determine the CORESET0 and PDCCH occasions (e.g., PDCCH monitoring occasions) of the R-UE.

[0204] The CSS and / or CORESET0 of the R-UE can be determined according to the above process. For example, if the CSS and CORESET0 of the R-UE are different from the CORESET0 of the legacy UE, or if the CORESET0 for the R-UE is outside the legacy initial DL BWP, the R-UE can determine that the initial DL R-BWP determined in association with the CORESET0 for the R-UE is active, operative, or valid. On the other hand, the R-UE can determine that the initial DL BWP of the legacy UE is deactivated, inoperative, or invalid.

[0205] In the NR system, PDCCH transmission and reception can be performed based on blind decoding of resources configured by the CORESET and search space set. The CORESET defines the region and characteristics of the resources where the PDCCH can be transmitted. Regarding the resource region, the size and position of the CORESET in the frequency domain and the size of the CORESET in the time domain can be given by the BS (the time domain positions for monitoring PDCCH candidates in the CORESET can be determined by the search space set).

[0206] As Figure 12As shown, when CSS is determined, the R-UE can detect the DCI format with CRC scrambled by a specific RNTI by monitoring the PDCCH for scheduling R-SIB1 during the corresponding time period. In this case, the specific RNTI can be a legacy SI-RNTI or an RNTI for R-SIB1 reception (e.g., an SI-RNTI dedicated to the R-UE). The DCI format can be defined as a legacy DCI format or a DCI format dedicated to the R-UE.

[0207] The DCI format for R-SIB1 may include at least some of the following information.

[0208] - FDRA (Frequency Domain Resource Allocation): Ceiling[log2{N RB DL,BWP (N RB DL,BWP +1) / 2}] bits, where N RB DL ,BWP is defined by the size of CORESET0.

[0209] - TDRA (Time Domain Resource Allocation)

[0210] - VRB to PRB mapping

[0211] - MCS (Modulation and Coding Scheme)

[0212] - RV (Redundancy Version)

[0213] - Aggregation factor: The aggregation factor indicates the number of times R-SIB1 is transmitted repeatedly (number of repetitions).

[0214] - SI (System Information) indicator: The SI indicator indicates whether SIB1 is R-SIB1 or a legacy SIB1 and / or whether SIBx is R-SIBx or a legacy SIBx.

[0215] - Reserved bits

[0216] For the R-UE, R-SIB1 may include information similar to that in the legacy SIB1. For example, R-SIB1 may include at least some of the following information.

[0217] - Scheduling information: Information about whether SIBx shared by legacy UEs and the R-UE is broadcast or its transmission time period, or information about whether R-SIBx dedicated to the R-UE is broadcast or its transmission time period

[0218] - RACH configuration information: RACH configuration information shared by legacy UEs and the R-UE or RACH configuration information dedicated to the R-UE

[0219] - Initial UL BWP information: Initial UL BWP configuration information shared by legacy UEs and R-UEs or initial UL BWP configuration information dedicated to R-UEs

[0220] - Access control information (access control parameters): Probability-based access control information shared by legacy UEs and R-UEs or probability-based access control information dedicated to R-UEs. When there are multiple types of R-UEs, the access control information can carry different parameter values for each type of R-UE. The R-UE can use the parameter values corresponding to the type of R-UE (e.g., restriction factor and restriction time) to determine probabilistically whether to allow UL transmissions for initial access.

[0221] The UE can request or receive the transmission of R-SIBx dedicated to the R-UE based on scheduling information.

[0222] Thereafter, the R-UE can receive the RAR (Msg2) or the contention resolution message (Msg4) in the initial DL R-BWP during the random access procedure. Then, the R-UE can receive the paging indicator or the paging message.

[0223] Meanwhile, priorities can be given to the MIB, SIB1, R-SIB1, and / or different (R-)SIBx. For example, the priority can be configured by R-SIB1. When the MIB, SIB1, R-SIB1, SIBx, and / or R-SIBx overlap with each other (e.g., when the MIB, SIB1, R-SIB1, SIBx, and / or R-SIBx overlap or conflict in the time domain), if the R-UE needs to receive all (or some) of the overlapping system information but the R-UE cannot receive the overlapping system information simultaneously, the R-UE can receive the selected information (e.g., including at least one of the MIB, SIB1, SIBx, and / or R-SIBx) according to the configured priority.

[0224] Figure 12 Figure 12 [Proposal #3] When selecting the initial cell, the R-UE can perform the legacy initial DL BWP until it receives at least SIB1 from the serving cell. After receiving SIB1, the R-UE can switch to the initial DL R-BWP to receive additional R-SIB1 and perform SIBx reception, paging, and random access operations. Figure 14 Figure 14

[0225] Figure 14 The figure illustrates an exemplary initial access procedure according to Proposal #2.

[0226] For example, the R-UE can receive the MIB (C05) from the selected cell during the initial cell selection procedure, the measurement procedure, and / or a mobility procedure such as handover.

[0227] The R-UE can check whether there is a CORESET for Type0-PDCCH CSS, i.e., CORESET0, based on the received MIB. If the R-UE supports the legacy CORESET0, the legacy CORESET0 and the legacy Type0-PDCCH CSS can be defined as the CORESET0 and the Type0-PDCCH CSS of the R-UE, respectively. The R-UE can receive PDCCH (C10 and C15) in the legacy CSS. For example, since the R-UE supports the legacy CORESET0 and the legacy CSS, the R-UE can also monitor PDCCH (C10 and C15) in the same way as the prior art (e.g., the BWP switches to the R-BWP at the timing t2 in Figure 14 ).

[0228] For example, when there is no CSS for the R-UE during the initial cell selection process, the measurement process, and / or the mobility process such as handover, the PBCH payload (e.g., pdcch-ConfigSIB1 or other information in the MIB) can provide (i) information about the frequency position where the SSB / SIB1 for the legacy UE or the SSB / R-SIB1 for the R-UE exists; and / or (ii) information about the frequency range where the SSB / SIB1 for the legacy UE or the SSB / R-SIB1 for the R-UE does not exist. For example, the BS can indicate the provided information based on the MIB (e.g., using the reserved bits of the MIB): whether the information (i) and / or (ii) is for the legacy UE or for the R-UE. The BS can use the MIB (e.g., the reserved bits of the MIB) to notify the R-UE whether it is necessary to measure the corresponding resources for cell reselection, mobility, or ANR. The R-UE can detect the frequency position of the SSB / R-SIB1 of the R-UE based on the provided information: information (i) and / or (ii). After receiving the MIB, the R-UE can determine the CORESET0 and the PDCCH timing of the R-UE.

[0229] Based on the CSS, the R-UE can detect the DCI format with a CRC scrambled by a specific RNTI by monitoring the PDCCH for scheduling the R-SIB1 during the corresponding period. In this case, the specific RNTI can be the legacy SI-RNTI or the RNTI for receiving the R-SIB1 dedicated to the R-UE. During the PDCCH reception operation, the R-UE can determine that the legacy initial DL BWP is activated and the initial DL R-BWP is deactivated. In this case, the DCI format is defined as the legacy DCI format (e.g., Figure 14 the DCI in (b)) or the DCI format dedicated to the R-UE (e.g., Figure 14 the R-DCI in (a) / (b)).

[0230] At least some of the following information can be sent via the DCI format for R-SIB1.

[0231] - FDRA: Ceiling[log2{N RB DL,BWP (N RB DL,BWP +1) / 2}] bits, where N RB DL,BWP is defined by the size of CORESET0.

[0232] - Information about CORESET0 that is only for R-UE

[0233] 1) Frequency-domain offset: The position of CORESET0 for R-UE relative to the frequency position where the PDCCH is transmitted can be indicated by an offset. The corresponding frequency-domain offset can be configured at the RB and / or RE level, and in this case, the RB-level offset may vary for each frequency band. Alternatively, the frequency-domain offset can be defined as the offset between the first or last RB of the SSB / PBCH and the first RB of CORESET0 for R-UE, or the frequency-domain offset can be defined as the offset between the first or last RB of the legacy CORESET0 and the first or last RB of CORESET0 for R-UE.

[0234] 2) Time-domain offset: The symbols of CORESET0 for R-UE relative to the symbols where the PDCCH is transmitted can be indicated by an offset. The time-domain offset can be set to the number of symbols. Alternatively, CORESET0 for R-UE can be configured to be located before or after the time-domain offset from the SSB / PBCH or the legacy CORESET0.

[0235] - TDRA (Time-domain Resource Allocation)

[0236] - VRB to PRB mapping

[0237] - MCS (Modulation and Coding Scheme)

[0238] - RV (Redundancy Version)

[0239] - Aggregation factor: The aggregation factor indicates the number of times R-SIB1 is transmitted repeatedly (the number of repetitions).

[0240] - SI indicator: The SI indicator indicates whether SIB1 is R-SIB1 or legacy SIB1 and / or whether SIBx is R-SIBx or legacy SIBx.

[0241] - Reserved bits

[0242] The UE may attempt to receive R-SIB1 (C20) via PDSCH based on the information included in the DCI.

[0243] To this end, the UE may determine that the initial DL R-BWP associated with the R-SIB1 transmission resource or the initial DL R-BWP determined in association with CORESET0 for the R-UE is active, operative, or valid. On the other hand, the R-UE may determine that the initial DL BWP for legacy UEs is deactivated, inoperative, or invalid.

[0244] For example, the content of R-SIB1 may be the same as that described in Proposal #1.

[0245] Alternatively, the R-UE may keep both the initial DL BWP and the initial DL R-BWP active and switch between the two BWPs such that the R-UE may alternately receive the PDCCH in the initial DL BWP and R-SIB1 in the initial DL R-BWP. Upon receiving R-SIB1 in the active initial DL R-BWP, the UE may request or receive the R-SIBx transmission dedicated to the R-UE based on the scheduling information in Proposal #1.

[0246] After switching to the initial DL R-BWP, the UE may monitor R-SIB1 in the initial DL R-BWP based on the CORESET0 information dedicated to the R-UE included in the DCI. As long as the R-UE receives the CORESET0 dedicated to the R-UE (e.g., as long as the R-UE receives the PDCCH scheduling R-SIB1), the R-UE does not need to switch to the legacy initial DL BWP for monitoring the PDCCH. Similarly as described in Proposal #1, if the CSS and CORESET0 of the R-UE are different from those of the legacy UE, or if the CORESET0 of the R-UE is outside the initial legacy DL BWP, the UE may determine that the initial DL R-BWP determined in association with the CORESET0 of the R-UE is active, operative, or valid. On the other hand, the UE may determine that the initial DL BWP is deactivated, inoperative, or invalid.

[0247] Thereafter, the R-UE may receive the RAR (Msg2) or the contention resolution message (Msg4) in the initial DL R-BWP during the random access procedure. Then, the R-UE may receive the paging indicator or the paging message.

[0248] Meanwhile, priority can be given to the MIB, SIB1, R-SIB1, and / or different (R-)SIBx. For example, the priority can be configured by R-SIB1. When the MIB, SIB1, R-SIB1, SIBx, and / or R-SIBx overlap with each other (e.g., when the MIB, SIB1, R-SIB1, SIBx, and / or R-SIBx overlap or conflict in the time domain), if the R-UE needs to receive all (or some) of the overlapping system information but the R-UE cannot receive the overlapping system information simultaneously, the R-UE can receive the selected information (e.g., including at least one of the MIB, SIB1, SIBx, and / or R-SIBx) according to the configured priority.

[0249] Figure 15 [Proposal #4] When selecting the initial cell, the R-UE can perform the legacy initial DL BWP until it receives at least SIB1 from the serving cell. After receiving SIB1, the R-UE can switch to the initial DL R-BWP and perform SIBx reception, paging, and random access operations. Figure 16 Figure 16

[0250] For example, the R-UE can receive the MIB from the selected cell during the initial cell selection process, the measurement process, and / or the mobility process such as handover.

[0251] The R-UE can check whether there is a CORESET for Type0-PDCCH CSS, i.e., CORESET0, based on the received MIB. When the R-UE supports the legacy CORESET0, the legacy CORESET0 and the legacy Type0-PDCCH CSS can be defined as the R-UE's CORESET0 and the R-UE's Type0-PDCCH CSS, respectively. The R-UE can receive the PDCCH in the legacy CSS. For example, because the R-UE supports the legacy CORESET0 and the legacy CSS, the R-UE can also monitor the PDCCH in the same way as the prior art. Thereafter, the R-UE can receive SIB1 shared by the legacy UE and the R-UE based on the legacy DCI received on the legacy PDCCH (e.g., Figure 17 ).

[0252] In this case, the legacy SIB1 can include at least some of the following information. After receiving the legacy SIB1, the R-UE can receive R-SIB1 by switching to the initial DL R-BWP based on this information (e.g., the BWP switches to the R-BWP at the timing t3 shown in Figure 17 ). Here, the R-UE can receive DCI in the initial DL R-BWP to receive R-SIB1 (e.g., Figure 17 (a)), or the R-UE can receive R-SIB1 without receiving DCI (e.g., Figure 17 (b)).

[0253] -FDRA: Ceiling[log2{N RB DL,BWP (N RB DL,BWP + 1) / 2}] bits, where N RB DL,BWP is defined by the size of CORESET0.

[0254] - Information on CORESET0 for R-UE only

[0255] 1) Frequency-domain offset: The position of CORESET0 for R-UE relative to the frequency position of the transmitted PDCCH can be indicated by an offset. The corresponding frequency-domain offset can be configured at the RB and / or RE level, and in this case, the RB-level offset may vary for each frequency band. Alternatively, the frequency-domain offset can be defined as the offset between the first or last RB of the SSB / PBCH and the first RB of CORESET0 for R-UE, or the frequency-domain offset can be defined as the offset between the first or last RB of the legacy CORESET0 and the first or last RB of CORESET0 for R-UE.

[0256] 2) Time-domain offset: Compared with the symbol of the transmitted PDCCH, the symbol of CORESET0 for R-UE can be indicated by an offset. The time-domain offset can be set to the number of symbols. Alternatively, CORESET0 for R-UE can be configured to be located before or after the time-domain offset of the SSB / PBCH or the legacy CORESET0.

[0257] - TDRA (Time-domain Resource Allocation)

[0258] - VRB to PRB mapping

[0259] - MCS (Modulation and Coding Scheme)

[0260] - RV (Redundancy Version)

[0261] - Aggregation factor: The aggregation factor indicates the number of times (repetition times) that R-SIB1 is repeatedly transmitted.

[0262] The R-UE may additionally receive DCI for receiving R-SIB1, similar to that described in Proposal #2 (e.g., Figure 17 (a)). After receiving the legacy SIB1, the UE may switch to the initial DL R-BWP (e.g., at Figure 18(At timing t3 as shown in (a), the BWP switches to the R-BWP) and the R-SIB1 is received based on the additional DCI. Alternatively, the R-UE may receive R-SIB1 transmission information, such as the DCI format of Proposal #2 with reserved bits of the legacy DCI (e.g., the DCI for scheduling SIB1). Thus, the R-UE may receive the R-SIB1 by switching to the initial DL R-BWP without additional DCI reception (e.g., at the BWP switch to the R-BWP at timing t3 in Figure 18 (the

[0263] For this purpose, the UE may determine that the initial DL R-BWP associated with the R-SIB1 transmission resource is active, operative, or valid. On the other hand, the R-UE may determine that the initial DL BWP for the legacy UE is deactivated, inoperative, or invalid. Alternatively, the R-UE may keep both the initial DL BWP and the initial DL R-BWP active and switch between the two BWPs so that the R-UE may alternately receive the two SIB1s.

[0264] For the R-UE, the legacy SIB1 or the R-SIB1 may include some or all of the following information. In particular, at least some of the following information may be included.

[0265] - Scheduling information: Information on whether the SIBx shared by the legacy UE and the R-UE is broadcast or its transmission period, or information on whether the R-SIBx dedicated to the R-UE is broadcast or its transmission period

[0266] - RACH configuration information: RACH configuration information shared by the legacy UE and the R-UE or RACH configuration information dedicated to the R-UE

[0267] - Initial UL BWP information: Initial UL BWP configuration information shared by the legacy UE and the R-UE or initial UL BWP configuration information dedicated to the R-UE

[0268] - Access control information (access control parameters): Probability-based access control information shared by the legacy UE and the R-UE or probability-based access control information dedicated to the R-UE. When there are multiple types of R-UEs, the access control information may carry different parameter values for each type of R-UE. The R-UE may determine probabilistically whether to allow UL transmission for initial access using the parameter values corresponding to the type of the R-UE (e.g., the restriction factor and the restriction time).

[0269] For example, scheduling information and initial UL BWP information for legacy SIBx can be included in and sent in legacy SIB1, and scheduling information, initial UL R-BWP information, RACH configuration information, and access control information (all dedicated to R-UE) for R-SIBx can be included in and sent in R-SIB1.

[0270] Thereafter, the UE can request or receive transmissions of R-SIBx based on the scheduling information in R-SIB1. The R-UE can receive an RAR or a contention resolution message in the initial DL R-BWP during the random access procedure. Then, the R-UE can receive a paging indicator or a paging message.

[0271] Meanwhile, priorities can be given to the MIB, SIB1, R-SIB1, and / or different (R-)SIBx. The priorities can be configured by SIB1 or R-SIB1. When the MIB, SIB1, R-SIB1, SIBx, and / or R-SIBx overlap with each other (for example, when the MIB, SIB1, R-SIB1, SIBx, and / or R-SIBx overlap or conflict in the time domain), if the R-UE needs to receive all (or some) of the overlapping system information, but the R-UE cannot receive the overlapping system information simultaneously, the R-UE can receive the selected information (for example, including at least one of the MIB, SIB1, SIBx, and / or R-SIBx) according to the configured priorities.

[0272] Figure 19 Figure 19 Figure 18 Figure 20

[0273] For example, the R-UE can receive the MIB from the selected cell during the initial cell selection procedure, the measurement procedure, and / or a mobility procedure such as handover.

[0274] The R-UE can check whether there is a CORESET for Type0-PDCCH CSS, i.e., CORESET0, based on the received MIB. When the R-UE supports the legacy CORESET0, the legacy CORESET0 and the legacy Type0-PDCCH CSS can be defined as the R-UE's CORESET0 and the R-UE's Type0-PDCCH CSS, respectively. The R-UE can receive PDCCH in the legacy CSS. For example, since the R-UE supports the legacy CORESET0 and the legacy CSS, the R-UE can also monitor PDCCH in the same way as in the prior art. Thereafter, the R-UE can receive SIB1 shared by the legacy UE and the R-UE based on the legacy DCI received through the legacy PDCCH. In this case, the content of SIB1 may be the same as that described in Proposal #1 (e.g., ​ ).

[0275] The UE can request or receive the transmission of R-SIBx based on the scheduling information in the R-SIB1 (e.g., at the timing t3 in ​ when the BWP switches to the R-BWP). For this purpose, the R-UE can determine that the initial DL R-BWP associated with the R-SIBx transmission resource is active, operative, or valid. On the other hand, the R-UE can determine that the initial DL R-BWP for the legacy UE is deactivated, inoperative, or invalid. Alternatively, the R-UE can keep both the initial DL BWP and the initial DL R-BWP active and switch between the two BWPs so that the R-UE can receive both SIB1 and R-SIBx periodically for different durations.

[0276] The R-UE can receive the RAR or the contention resolution message in the initial DL R-BWP during the random access procedure. Then, the R-UE can receive the paging indicator or the paging message.

[0277] Meanwhile, priorities can be given to the MIB, SIB1, and / or different (R-)SIBx. The priorities can be configured by SIB1. When the MIB, SIB1, SIBx, and / or R-SIBx overlap (e.g., when the MIB, SIB1, SIBx, and / or R-SIBx overlap or conflict in the time domain), if the R-UE needs to receive all (or some) of the overlapping system information but the R-UE cannot receive the overlapping system information simultaneously, the R-UE can receive the selected information (e.g., including at least one of the MIB, SIB1, SIBx, and / or R-SIBx) according to the configured priorities.

[0278] According to the proposal mentioned above, an initial DL R-BWP dedicated to the R-UE can be effectively provided. Therefore, the R-UE supporting limited UE capabilities can successfully perform the cell access procedure and coexist with legacy UEs.

[0279] ​ The figure illustrates an exemplary signal transmission / reception method based on the proposal mentioned above. ​ is one of the examples to which the present disclosure can be applied, and the present disclosure is not limited to ​ the example of. For ​ the illustration of, reference can be made to the above details, even if not explicitly stated.

[0280] The BS can transmit a PBCH signal (D05) in the SSB on the first DL BWP (e.g., ​ BWP1). The UE can detect the PBCH signal in the SSB on the first DL BWP. The UE can obtain partial system information including the MIB carried by the PBCH signal from among the first system information provided on the first DL BWP (D10).

[0281] The BS can transmit second system information (D20) on a second DL BWP different from the first DL BWP. The BS can support a first type of UE (e.g., Release 15 / 16 NR UE) and a second type of UE with reduced capabilities supporting a smaller bandwidth than the first type of UE (e.g., Release 17+ RedCap UE). The BS can provide partial system information including the MIB carried by the PBCH signal to the second type of UE by transmitting the first system information on the first DL BWP. The BS can provide the remaining system information to the second type of UE by transmitting the second system information on the second DL BWP.

[0282] Based on the UE being the second type of UE, which has reduced capabilities supporting a smaller bandwidth than the first type of UE, the UE can perform a BWP switch from the first DL BWP to the second DL BWP (D15). The UE can obtain the second system information provided on the second DL BWP as the remaining part in addition to the partial system information obtained on the first DL BWP (D25).

[0283] The UE can perform cell access based on multiple initial DL BWPs.

[0284] The first DL BWP and the second DL BWP can be the first initial DL BWP and the second initial DL BWP, respectively.

[0285] The first DL BWP may be related to the bandwidth of the first type of UE, and the second DL BWP may be related to the bandwidth of the second type of UE.

[0286] The PBCH signal on the first DL BWP may be a common signal for the first type of UE and the second type of UE.

[0287] The second system information may be information for the second type of UE rather than for the first type of UE. The second system information may include at least one second type of SIB for the second type of UE.

[0288] The UE obtaining partial system information on the first DL BWP may include: obtaining a first CORESET configuration and a first CSS configuration from the MIB, where the first CORESET configuration and the first CSS configuration are related to the control information scheduling the first type of SIB1 for the first type of UE; and obtaining the first type of SIB1 based on the first CORESET configuration and the first CSS configuration.

[0289] The UE obtaining the second system information on the second DL BWP may include obtaining at least one second type of SIB provided on the second DL BWP based on the first type of SIB1.

[0290] The UE obtaining partial system information on the first DL BWP may include obtaining a first CORESET configuration and a first CSS configuration from the MIB, where the first CORESET configuration and the first CSS configuration are related to the control information scheduling the first type of SIB1 for the first type of UE.

[0291] The UE obtaining the second system information on the second DL BWP may include: - obtaining at least one of a second CORESET configuration or a second CSS configuration on the second DL BWP by applying a time / frequency offset to at least one of the first CORESET configuration or the first CSS configuration; and obtaining at least one second type of SIB provided on the second DL BWP based on at least one of the second CORESET configuration or the second CSS configuration.

[0292] ​ FIG. 1 shows a communication system 1 to which the present disclosure is applied.

[0293] Reference ​, the communication system 1 applied to the present disclosure includes a wireless device, a base station (BS), and a network. Herein, the wireless device refers to a device that performs communication using a radio access technology (RAT) (e.g., 5G new RAT (NR) or Long Term Evolution (LTE)), and may be referred to as a communication / radio / 5G device. The wireless device may include (but is not limited to) a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a household appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, the vehicle may include a vehicle with wireless communication capabilities, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. Herein, the vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television, a smart phone, a computer, a wearable device, a household appliance device, a digital sign, a vehicle, a robot, etc. The handheld device may include a smart phone, a smart board, a wearable device (e.g., a smart watch or smart glasses), and a computer (e.g., a notebook). The household appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include sensors and smart meters. For example, the BS and the network may be implemented as wireless devices, and a specific wireless device 200a may operate as a BS / network node relative to other wireless devices.

[0294] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. AI technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BS / network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0295] Wireless communication / connections 150a, 150b, or 150c can be established between wireless devices 100a to 100f / BS 200 or between BS 200 / BS 200. In this document, wireless communication / connections can be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication), or inter-BS communication (e.g., relay, integrated access backhaul (IAB)). The wireless device and the BS / wireless device can send / receive radio signals to / from each other through wireless communication / connections 150a and 150b. For example, wireless communication / connections 150a and 150b can send / receive signals through various physical channels. To this end, at least a part of the various configuration information for configuring the processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and resource allocation processes can be executed based on various proposals of the present disclosure.

[0296] ​ Shows a wireless device applicable to the present disclosure.

[0297] Refer to ​ , the first wireless device 100 and the second wireless device 200 can send radio signals through various RATs (e.g., LTE and NR). In this document, {the first wireless device 100 and the second wireless device 200} can correspond to ​ {wireless device 100x and BS 200} and / or {wireless device 100x and wireless device 100x}.

[0298] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. For example, the processor 102 may process the information in the memory 104 to generate first information / signals, and then transmit radio signals including the first information / signals through the transceiver 106. The processor 102 may receive radio signals including second information / signals through the transceiver 106, and then store the information obtained by processing the second information / signals in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software codes including commands for executing part or all of the processes controlled by the processor 102 or for implementing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Herein, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0299] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. For example, the processor 202 may process the information within the memory 204 to generate third information / signals, and then transmit radio signals including the third information / signals through the transceiver 206. The processor 202 may receive radio signals including fourth information / signals through the transceiver 206, and then store the information obtained by processing the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software codes including commands for executing part or all of the processes controlled by the processor 202 or for implementing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. Herein, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with the RF unit. In this disclosure, the wireless device may represent a communication modem / circuit / chip.

[0300] In the following, the hardware components of wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by (but not limited to) one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document, and provide the generated signals to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive signals (e.g., baseband signals) from one or more transceivers 106 and 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document.

[0301] One or more processors 102 and 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processor devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be configured to include modules, procedures, or functions. The firmware or software configured to execute the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 to be driven by one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of code, commands, and / or command sets.

[0302] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories 104 and 204 may be configured by read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard disk drive, register, cache memory, computer-readable storage medium, and / or combinations thereof. One or more memories 104 and 204 may be located inside and / or outside one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 by various techniques such as wired or wireless connections.

[0303] One or more transceivers 106 and 206 may send user data, control information, and / or radio signals / channels mentioned in the methods and / or operation flowcharts of this document to one or more other devices. One or more transceivers 106 and 206 may receive descriptions, functions, processes, proposals, methods, and / or user data, control information, and / or radio signals / channels mentioned in the operation flowcharts disclosed in this document from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202 and send and receive radio signals. For example, one or more processors 102 and 202 may execute control so that one or more transceivers 106 and 206 can send user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 may execute control so that one or more transceivers 106 and 206 can receive user data, control information, or radio signals from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to send and receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document through one or more antennas 108 and 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert the received radio signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert the user data, control information, radio signals / channels, etc. processed using one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0304] ​ is a diagram showing the DRX operation of a UE according to an embodiment of the present disclosure.

[0305] The UE can perform DRX operations in the processes and / or methods described / proposed above. A UE configured with DRX can reduce power consumption by receiving DL signals discontinuously. DRX can be performed in the RRC_IDLE state, the RRC_INACTIVE state, and the RRC_CONNECTED state. The UE performs DRX in the RRC_IDLE state and the RRC_INACTIVE state to receive paging signals discontinuously. The DRX in the RRC_CONNECTED state (RRC_CONNECTED DRX) will be described below.

[0306] The DRX cycle includes an on-duration and a DRX opportunity. The DRX cycle defines the time interval between periodic repetitions of the on-duration. The on-duration is the time period during which the UE monitors the PDCCH. When the UE is configured with DRX, the UE performs PDCCH monitoring during the on-duration. When the UE successfully detects the PDCCH during PDCCH monitoring, the UE starts an inactivity timer and remains awake. In contrast, when the UE fails to detect any PDCCH during PDCCH monitoring, the UE transitions to the sleep state after the on-duration. Therefore, when DRX is configured, PDCCH monitoring / reception can be performed discontinuously in the time domain in the processes and / or methods described / proposed above. For example, when DRX is configured, the PDCCH reception timing (e.g., the time slot with PDCCH SS) can be configured discontinuously according to the DRX configuration in the present disclosure. In contrast, when DRX is not configured, PDCCH monitoring / reception can be performed continuously in the time domain. For example, when DRX is not configured, the PDCCH reception timing (e.g., the time slot with PDCCH SS) can be configured continuously in the present disclosure. Regardless of whether DRX is configured, PDCCH monitoring can be restricted during the time period configured as a measurement gap.

[0307] The above embodiments are combinations of elements and features of the present disclosure in specific forms. Unless otherwise mentioned, these elements or features can be considered optional. Each element or feature can be implemented without being combined with other elements or features. In addition, embodiments of the present disclosure can be configured by combining some elements and / or some features. The operation order described in the embodiments of the present disclosure can be rearranged. Some structures or features of any one embodiment can be included in another embodiment, or can be replaced with the corresponding structures or features of another embodiment. Obviously, the claims that are not explicitly cited in the appended claims can be presented as combinations of embodiments of the present disclosure, or can be included as new claims through subsequent amendments after the application is filed.

[0308] Those skilled in the art will understand that the present disclosure can be implemented in other specific ways different from those described herein without departing from the spirit and basic characteristics of the present disclosure. Therefore, the above embodiments are to be construed in all respects as illustrative and not restrictive. The scope of the present disclosure should be determined by the appended claims and their legal equivalents, rather than by the above description, and all variations falling within the meaning and scope of equivalence of the appended claims should be included therein.

[0309] Industrial applicability

[0310] The present disclosure is applicable to a UE, a BS, or other devices in a wireless mobile communication system.

Claims

1. A method performed by a user equipment (UE), the method comprising: Detecting a physical broadcast channel (PBCH) signal via a synchronization signal block (SSB); And Obtaining system information including first system information based on the PBCH signal, the first system information being configured for a first initial downlink (DL) bandwidth part (BWP) and including information about a first initial uplink (UL) BWP, Wherein a first random access channel (RACH) configuration is included in the first system information, Wherein, based on the UE being a second type of UE having reduced capabilities compared to a first type of UE, obtaining the system information includes: Obtaining second system information for the second type of UE, the second system information being configured for a second initial DL BWP dedicated to the second type of UE and including information about a second initial UL BWP dedicated to the second type of UE, Wherein the UE operates on the second initial DL BWP instead of on the first initial DL BWP, Wherein the UE performs a random access procedure based on a second RACH configuration provided for the second type of UE, and Wherein the second RACH configuration is included in the second system information.

2. The method according to claim 1, wherein, The second initial DL BWP does not exceed the maximum bandwidth of the second type of UE.

3. The method according to claim 1, wherein, The PBCH signal is a common signal for the first type of UE and the second type of UE.

4. A processor-readable storage medium having stored thereon a program for performing the method of claim 1.

5. A device, comprising: A memory configured to store instructions; And A processor configured to perform operations by executing the instructions, Wherein the operations performed by the processor include: Detecting a physical broadcast channel (PBCH) signal via a synchronization signal block (SSB); and Obtaining system information including first system information based on the PBCH signal, the first system information being configured for a first initial downlink (DL) bandwidth part (BWP) and including information about a first initial uplink (UL) BWP, Wherein a first random access channel (RACH) configuration is included in the first system information, Wherein, based on the device being a second type of device having reduced capabilities compared to a first type of device, obtaining the system information includes: Obtaining second system information for the second type of device, the second system information being configured for a second initial DL BWP dedicated to the second type of device and including information about a second initial UL BWP dedicated to the second type of device, Wherein the device operates on the second initial DL BWP instead of on the first initial DL BWP, Wherein the device performs a random access procedure based on a second RACH configuration provided for the second type of device, and Wherein the second RACH configuration is included in the second system information.

6. The apparatus according to claim 5, further comprising: a transceiver configured to transmit and receive radio signals under the control of the processor, wherein the apparatus is a user equipment (UE).

7. The device according to claim 5, wherein The apparatus is an application specific integrated circuit (ASIC) or a digital signal processing device.

8. A method performed by a base station, the method comprising: transmitting a physical broadcast channel (PBCH) signal via a synchronization signal block (SSB); and transmitting system information including first system information based on the PBCH signal, the first system information being configured for a first initial downlink (DL) bandwidth part (BWP) and including information about a first initial uplink (UL) BWP, wherein a first random access channel (RACH) configuration is included in the first system information, wherein, based on the base station being configured to support both a first type of user equipment (UE) and a second type of UE having reduced capabilities compared to the first type of UE, transmitting the system information includes: transmitting second system information for the second type of UE, the second system information being configured for a second initial DL BWP dedicated to the second type of UE and including information about a second initial UL BWP dedicated to the second type of UE, wherein the base station communicates with the second type of UE on the second initial DL BWP rather than the first initial DL BWP, wherein the base station performs a random access procedure with the second type of UE based on a second RACH configuration provided for the second type of UE, and wherein the second RACH configuration is included in the second system information.

9. A base station, comprising: a memory configured to store instructions; and a processor configured to perform operations by executing the instructions, wherein the operations performed by the processor include: transmitting a physical broadcast channel (PBCH) signal via a synchronization signal block (SSB); and transmitting system information including first system information based on the PBCH signal, the first system information being configured for a first initial downlink (DL) bandwidth part (BWP) and including information about a first initial uplink (UL) BWP, wherein a first random access channel (RACH) configuration is included in the first system information, wherein, based on the base station being configured to support both a first type of user equipment (UE) and a second type of UE having reduced capabilities compared to the first type of UE, transmitting the system information includes: transmitting second system information for the second type of UE, the second system information being configured for a second initial DL BWP dedicated to the second type of UE and including information about a second initial UL BWP dedicated to the second type of UE, wherein the base station communicates with the second type of UE on the second initial DL BWP rather than the first initial DL BWP, Wherein, the base station performs a random access procedure with the second type of UE based on a second RACH configuration provided for the second type of UE, and wherein, the second RACH configuration is included in the second system information.

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