Patent Description:
As more and more communication devices require more communication capacity, there is a need for improved mobile broadband communication over existing radio access technology. Also, massive machine type communications (MTC), which provides various services by connecting many devices and objects, is one of the major issues to be considered in the next generation communication. In addition, communication system design considering reliability/latency sensitive service/UE is being discussed. The introduction of next generation radio access technology considering enhanced mobile broadband communication (eMBB), massive MTC (mMTC), ultra-reliable and low latency communication (URLLC) is discussed. This new technology may be called new radio access technology (new RAT or NR) in the present disclosure for convenience. NR is also called the fifth generation (<NUM>) system.

The improvement in performance and functions of a user equipment (UE) such as an increase in UE's display resolution, display size, processors, memories, and applications results in an increase in power consumption. It is important for the UE to reduce power consumption since power supply may be limited to a battery. This is also applied to a UE operating in NR.

One example for reducing power consumption of the UE includes a discontinuous reception (DRX) operation. The UE may need to monitor a physical downlink control channel (PDCCH) in every subframe to know whether there is data to be received. Since the UE does not always receive data in all subframes, such an operation results in unnecessary significant battery consumption. DRX is an operation for reducing the battery consumption. That is, the UE wakes up with a period of a DRX cycle to monitor a PDCCH during a determined time (DRX on duration). If there is no PDCCH detection during the time, the UE enters a sleeping mode, i.e., a state in which a radio frequency (RF) transceiver is turned off. In the presence of the PDCCH detection during the time, a PDCCH monitoring time may be extended, and data transmission and reception may be performed based on the detected PDCCH.

An additional method of reducing power consumption may also be required for the DRX operation. <CIT> relates to a UE that can monitor a downlink (DL) control channel for DL control information (DCI) at a predetermined monitoring occasion, wherein the predetermined monitoring occasion has a periodicity of P slots or P symbols with an offset Os. The UE can monitor a downlink (DL) control channel for DL control information (DCI) at a predetermined monitoring occasion, wherein Os has an offset with respect to a first slot in subframe number zero (SFN#<NUM>). The UE can monitor a downlink (DL) control channel for DL control information (DCI) at a predetermined monitoring occasion, wherein P is a positive integer greater than zero.

The present disclosure provides a method of monitoring a physical downlink control channel in a wireless communication system, and an apparatus using the method.

In one aspect, provided is a method according to claim <NUM>.

In another aspect, provided is a user equipment (UE) according to claim <NUM>.

In the present specification, "A or B" may mean "only A", "only B" or "both A and B". In other words, in the present specification, "A or B" may be interpreted as "A and/or B". For example, in the present specification, "A, B, or C" may mean "only A", "only B", "only C", or "any combination of A, B, C".

A slash (/) or comma used in the present specification may mean "and/or". For example, "A, B, C" may mean "A, B, or C".

In the present specification, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, in the present specification, the expression "at least one of A or B" or "at least one of A and/or B" may be interpreted as "at least one of A and B".

In addition, in the present specification, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B, and/or C" may mean "at least one of A, B, and C".

Technical features described individually in one figure in the present specification may be individually implemented, or may be simultaneously implemented.

<FIG> shows a wireless communication system to which the present disclosure may be applied. The wireless communication system may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE)/LTE-A system.

The E-UTRAN includes at least one base station (BS) <NUM> which provides a control plane and a user plane to a user equipment (UE) <NUM>. The UE <NUM> may be fixed or mobile, and may be referred to as another terminology, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. The BS <NUM> is generally a fixed station that communicates with the UE <NUM> and may be referred to as another terminology, such as an evolved node-B (eNB), a base transceiver system (BTS), an access point, etc..

The BSs <NUM> are interconnected by means of an X2 interface. The BSs <NUM> are also connected by means of an S1 interface to an evolved packet core (EPC) <NUM>, more specifically, to a mobility management entity (MME) through S1-MME and to a serving gateway (S-GW) through S1-U.

The EPC <NUM> includes an MME, an S-GW, and a packet data network-gateway (P-GW). The MME has access information of the UE or capability information of the UE, and such information is generally used for mobility management of the UE. The S-GW is a gateway having an E-UTRAN as an end point. The P-GW is a gateway having a PDN as an end point.

Layers of a radio interface protocol between the UE and the network can be classified into a first layer (L1), a second layer (L2), and a third layer (L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system. Among them, a physical (PHY) layer belonging to the first layer provides an information transfer service by using a physical channel, and a radio resource control (RRC) layer belonging to the third layer serves to control a radio resource between the UE and the network. For this, the RRC layer exchanges an RRC message between the UE and the BS.

<FIG> is a diagram showing a wireless protocol architecture for a user plane. <FIG> is a diagram showing a wireless protocol architecture for a control plane. The user plane is a protocol stack for user data transmission. The control plane is a protocol stack for control signal transmission.

Referring to <FIG> and <FIG>, a PHY layer provides an upper layer(=higher layer) with an information transfer service through a physical channel. The PHY layer is connected to a medium access control (MAC) layer which is an upper layer of the PHY layer through a transport channel. Data is transferred between the MAC layer and the PHY layer through the transport channel. The transport channel is classified according to how and with what characteristics data is transferred through a radio interface.

Data is moved between different PHY layers, that is, the PHY layers of a transmitter and a receiver, through a physical channel. The physical channel may be modulated according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and use the time and frequency as radio resources.

The functions of the MAC layer include mapping between a logical channel and a transport channel and multiplexing and demultiplexing to a transport block that is provided through a physical channel on the transport channel of a MAC Service Data Unit (SDU) that belongs to a logical channel. The MAC layer provides service to a Radio Link Control (RLC) layer through the logical channel.

The functions of the RLC layer include the concatenation, segmentation, and reassembly of an RLC SDU. In order to guarantee various types of Quality of Service (QoS) required by a Radio Bearer (RB), the RLC layer provides three types of operation mode: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through an Automatic Repeat Request (ARQ).

The RRC layer is defined only on the control plane. The RRC layer is related to the configuration, reconfiguration, and release of radio bearers, and is responsible for control of logical channels, transport channels, and PHY channels. An RB means a logical route that is provided by the first layer (PHY layer) and the second layers (MAC layer, the RLC layer, and the PDCP layer) in order to transfer data between UE and a network.

The function of a Packet Data Convergence Protocol (PDCP) layer on the user plane includes the transfer of user data and header compression and ciphering. The function of the PDCP layer on the user plane further includes the transfer and encryption/integrity protection of control plane data.

What an RB is configured means a process of defining the characteristics of a wireless protocol layer and channels in order to provide specific service and configuring each detailed parameter and operating method. An RB can be divided into two types of a Signaling RB (SRB) and a Data RB (DRB). The SRB is used as a passage through which an RRC message is transmitted on the control plane, and the DRB is used as a passage through which user data is transmitted on the user plane.

If RRC connection is established between the RRC layer of UE and the RRC layer of an E-UTRAN, the UE is in the RRC connected state. If not, the UE is in the RRC idle state.

A downlink transport channel through which data is transmitted from a network to UE includes a broadcast channel (BCH) through which system information is transmitted and a downlink shared channel (SCH) through which user traffic or control messages are transmitted. Traffic or a control message for downlink multicast or broadcast service may be transmitted through the downlink SCH, or may be transmitted through an additional downlink multicast channel (MCH). Meanwhile, an uplink transport channel through which data is transmitted from UE to a network includes a random access channel (RACH) through which an initial control message is transmitted and an uplink shared channel (SCH) through which user traffic or control messages are transmitted.

Logical channels that are placed over the transport channel and that are mapped to the transport channel include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), and a multicast traffic channel (MTCH).

The physical channel includes several OFDM symbols in the time domain and several subcarriers in the frequency domain. One subframe includes a plurality of OFDM symbols in the time domain. An RB is a resources allocation unit, and includes a plurality of OFDM symbols and a plurality of subcarriers. Furthermore, each subframe may use specific subcarriers of specific OFDM symbols (e.g., the first OFDM symbol) of the corresponding subframe for a physical downlink control channel (PDCCH), that is, an L1/L2 control channel. A Transmission Time Interval (TTI) is a unit time for subframe transmission.

Hereinafter, a new radio access technology (new RAT, NR) will be described.

As more and more communication devices require more communication capacity, there is a need for improved mobile broadband communication over existing radio access technology. Also, massive machine type communications (MTC), which provides various services by connecting many devices and objects, is one of the major issues to be considered in the next generation communication. In addition, communication system design considering reliability/latency sensitive service/UE is being discussed. The introduction of next generation radio access technology considering enhanced mobile broadband communication (eMBB), massive MTC (mMTC), ultrareliable and low latency communication (URLLC) is discussed. This new technology may be called new radio access technology (new RAT or NR) in the present disclosure for convenience.

<FIG> illustrates a system structure of a next generation radio access network (NG-RAN) to which NR is applied.

Referring to <FIG>, the NG-RAN may include a gNB and/or an eNB that provides user plane and control plane protocol termination to a terminal. <FIG> illustrates the case of including only gNBs. The gNB and the eNB are connected by an Xn interface. The gNB and the eNB are connected to a <NUM> core network (5GC) via an NG interface. More specifically, the gNB and the eNB are connected to an access and mobility management function (AMF) via an NG-C interface and connected to a user plane function (UPF) via an NG-U interface.

<FIG> illustrates a functional division between an NG-RAN and a 5GC.

Referring to <FIG>, the gNB may provide functions such as an inter-cell radio resource management (Inter Cell RRM), radio bearer management (RB control), connection mobility control, radio admission control, measurement configuration & provision, dynamic resource allocation, and the like. The AMF may provide functions such as NAS security, idle state mobility handling, and so on. The UPF may provide functions such as mobility anchoring, PDU processing, and the like. The SMF may provide functions such as UE IP address assignment, PDU session control, and so on.

<FIG> illustrates an example of a frame structure that may be applied in NR.

Referring to <FIG>, in the NR, a radio frame (hereinafter, also referred to as a frame) may be used in uplink and downlink transmissions. The frame has a length of <NUM>, and may be defined as two <NUM> half-frames (HFs). The HF may be defined as five <NUM> subframes (SFs). The SF may be divided into one or more slots, and the number of slots within the SF depends on a subcarrier spacing (SCS). Each slot includes <NUM> or <NUM> OFDM(A) symbols according to a cyclic prefix (CP). In case of using a normal CP, each slot includes <NUM> symbols. In case of using an extended CP, each slot includes <NUM> symbols.

The following table <NUM> illustrates a subcarrier spacing configuration µ.

The following table <NUM> illustrates the number of slots in a frame (Nframe,µslot), the number of slots in a subframe (Nsubframe,µslot), the number of symbols in a slot (Nslotsymb), and the like, according to subcarrier spacing configurations µ.

<FIG> illustrates a case of µ=<NUM>, <NUM>, <NUM>, <NUM>.

Table <NUM>-<NUM> below illustrates that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS, in case of using an extended CP.

In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, and so on) may be differently configured between a plurality of cells integrated to one UE. Accordingly, an (absolute time) duration of a time resource (e.g., SF, slot or TTI) (for convenience, collectively referred to as a time unit (TU)) configured of the same number of symbols may be differently configured between the integrated cells.

<FIG> illustrates a slot structure of an NR frame.

A slot may include a plurality of symbols in a time domain. A carrier may include a plurality of subcarriers in a frequency domain. A resource block (RB) may be defined as a plurality of consecutive subcarriers (e.g., <NUM> subcarriers) in the frequency domain. A bandwidth part (BWP) may be defined as a plurality of consecutive (physical) resource blocks ((P)RBs) in the frequency domain, and the BWP may correspond to one numerology (e.g., SCS, CP length, and so on). The carrier may include up to N (e.g., <NUM>) BWPs. Data communication may be performed via an activated BWP, and only one BWP may be activated for one UE. In a resource grid, each element may be referred to as a resource element (RE), and one complex symbol may be mapped thereto.

A physical downlink control channel (PDCCH) may include one or more control channel elements (CCEs) as illustrated in the following table <NUM>.

That is, the PDCCH may be transmitted through a resource including <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> CCEs. Here, the CCE includes six resource element groups (REGs), and one REG includes one resource block in a frequency domain and one orthogonal frequency division multiplexing (OFDM) symbol in a time domain.

Monitoring implies decoding of each PDCCH candidate according to a downlink control information (DCI) format. The UE monitors a set of PDCCH candidates in one or more CORESETs (to be described below) on an active DL BWP of each activated serving cell in which PDCCH monitoring is configured, according to a corresponding search space set.

A new unit called a control resource set (CORESET) may be introduced in the NR. The UE may receive a PDCCH in the CORESET.

Referring to <FIG>, the CORESET includes NCORESETRB number of resource blocks in the frequency domain, and NCORESETsymb ∈ { <NUM>, <NUM>, <NUM>} number of symbols in the time domain. NCORESETRB and NCORESETsymb may be provided by a base station via higher layer signaling. As illustrated in <FIG>, a plurality of CCEs (or REGs) may be included in the CORESET.

The UE may attempt to detect a PDCCH in units of <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> CCEs in the CORESET. One or a plurality of CCEs in which PDCCH detection may be attempted may be referred to as PDCCH candidates.

A plurality of CORESETs may be configured for the terminal.

<FIG> is a diagram illustrating a difference between a related art control region and the CORESET in NR.

Referring to <FIG>, a control region <NUM> in the related art wireless communication system (e.g., LTE/LTE-A) is configured over the entire system band used by a base station (BS). All the terminals, excluding some (e.g., eMTC/NB-IoT terminal) supporting only a narrow band, must be able to receive wireless signals of the entire system band of the BS in order to properly receive/decode control information transmitted by the BS.

On the other hand, in NR, CORESET described above was introduced. CORESETs <NUM>, <NUM>, and <NUM> are radio resources for control information to be received by the terminal and may use only a portion, rather than the entirety of the system bandwidth. The BS may allocate the CORESET to each UE and may transmit control information through the allocated CORESET. For example, in <FIG>, a first CORESET <NUM> may be allocated to UE <NUM>, a second CORESET <NUM> may be allocated to UE <NUM>, and a third CORESET <NUM> may be allocated to UE <NUM>. In the NR, the terminal may receive control information from the BS, without necessarily receiving the entire system band.

The CORESET may include a UE-specific CORESET for transmitting UE-specific control information and a common CORESET for transmitting control information common to all UEs.

Meanwhile, NR may require high reliability according to applications. In such a situation, a target block error rate (BLER) for downlink control information (DCI) transmitted through a downlink control channel (e.g., physical downlink control channel (PDCCH)) may remarkably decrease compared to those of conventional technologies. As an example of a method for satisfying requirement that requires high reliability, content included in DCI can be reduced and/or the amount of resources used for DCI transmission can be increased. Here, resources can include at least one of resources in the time domain, resources in the frequency domain, resources in the code domain and resources in the spatial domain.

In NR, the following technologies/features can be applied.

<FIG> illustrates an example of a frame structure for new radio access technology.

In NR, a structure in which a control channel and a data channel are time-division-multiplexed within one TTI, as shown in <FIG>, can be considered as a frame structure in order to minimize latency.

In <FIG>, a shaded region represents a downlink control region and a black region represents an uplink control region. The remaining region may be used for downlink (DL) data transmission or uplink (UL) data transmission. This structure is characterized in that DL transmission and UL transmission are sequentially performed within one subframe and thus DL data can be transmitted and UL ACK/NACK can be received within the subframe. Consequently, a time required from occurrence of a data transmission error to data retransmission is reduced, thereby minimizing latency in final data transmission.

In this data and control TDMed subframe structure, a time gap for a base station and a terminal to switch from a transmission mode to a reception mode or from the reception mode to the transmission mode may be required. To this end, some OFDM symbols at a time when DL switches to UL may be set to a guard period (GP) in the self-contained subframe structure.

<FIG> illustrates a structure of a self-contained slot.

In an NR system, a DL control channel, DL or UL data, a UL control channel, and the like may be contained in one slot. For example, first N symbols (hereinafter, DL control region) in the slot may be used to transmit a DL control channel, and last M symbols (hereinafter, UL control region) in the slot may be used to transmit a UL control channel. N and M are integers greater than or equal to <NUM>. A resource region (hereinafter, a data region) which exists between the DL control region and the UL control region may be used for DL data transmission or UL data transmission. For example, the following configuration may be considered. Respective durations are listed in a temporal order.

A PDCCH may be transmitted in the DL control region, and a physical downlink shared channel (PDSCH) may be transmitted in the DL data region. A physical uplink control channel (PUCCH) may be transmitted in the UL control region, and a physical uplink shared channel (PUSCH) may be transmitted in the UL data region. Downlink control information (DCI), for example, DL data scheduling information, UL data scheduling information, and the like, may be transmitted on the PDCCH. Uplink control information (UCI), for example, ACK/NACK information about DL data, channel state information (CSI), and a scheduling request (SR), may be transmitted on the PUCCH. A GP provides a time gap in a process in which a BS and a UE switch from a TX mode to an RX mode or a process in which the BS and the UE switch from the RX mode to the TX mode. Some symbols at the time of switching from DL to UL within a subframe may be configured as the GP.

Wavelengths are shortened in millimeter wave (mmW) and thus a large number of antenna elements can be installed in the same area. That is, the wavelength is <NUM> at <NUM> and thus a total of <NUM> antenna elements can be installed in the form of a <NUM>-dimensional array at an interval of <NUM> lambda (wavelength) in a panel of <NUM>×<NUM>. Accordingly, it is possible to increase a beamforming (BF) gain using a large number of antenna elements to increase coverage or improve throughput in mmW.

In this case, if a transceiver unit (TXRU) is provided to adjust transmission power and phase per antenna element, independent beamforming per frequency resource can be performed. However, installation of TXRUs for all of about <NUM> antenna elements decreases effectiveness in terms of cost. Accordingly, a method of mapping a large number of antenna elements to one TXRU and controlling a beam direction using an analog phase shifter is considered. Such analog beamforming can form only one beam direction in all bands and thus cannot provide frequency selective beamforming.

Hybrid beamforming (BF) having a number B of TXRUs which is smaller than Q antenna elements can be considered as an intermediate form of digital BF and analog BF. In this case, the number of directions of beams which can be simultaneously transmitted are limited to B although it depends on a method of connecting the B TXRUs and the Q antenna elements.

When a plurality of antennas is used in NR, hybrid beamforming which is a combination of digital beamforming and analog beamforming is emerging. Here, in analog beamforming (or RF beamforming) an RF end performs precoding (or combining) and thus it is possible to achieve the performance similar to digital beamforming while reducing the number of RF chains and the number of D/A (or A/D) converters. For convenience, the hybrid beamforming structure may be represented by N TXRUs and M physical antennas. Then, the digital beamforming for the L data layers to be transmitted at the transmitting end may be represented by an N by L matrix, and the converted N digital signals are converted into analog signals via TXRUs, and analog beamforming represented by an M by N matrix is applied.

System information of the NR system may be transmitted in a broadcasting manner. In this case, in one symbol, analog beams belonging to different antenna panels may be simultaneously transmitted. A scheme of introducing a beam RS (BRS) which is a reference signal (RS) transmitted by applying a single analog beam (corresponding to a specific antenna panel) is under discussion to measure a channel per analog beam. The BRS may be defined for a plurality of antenna ports, and each antenna port of the BRS may correspond to a single analog beam. In this case, unlike the BRS, a synchronization signal or an xPBCH may be transmitted by applying all analog beams within an analog beam group so as to be correctly received by any UE.

In the NR, in a time domain, a synchronization signal block (SSB, or also referred to as a synchronization signal and physical broadcast channel (SS/PBCH)) may consist of <NUM> OFDM symbols indexed from <NUM> to <NUM> in an ascending order within a synchronization signal block, and a PBCH associated with a primary synchronization signal (PSS), secondary synchronization signal (SSS), and demodulation reference signal (DMRS) may be mapped to the symbols. As described above, the synchronization signal block may also be represented by an SS/PBCH block.

In NR, since a plurality of synchronization signal blocks(SSBs) may be transmitted at different times, respectively, and the SSB may be used for performing initial access (IA), serving cell measurement, and the like, it is preferable to transmit the SSB first when transmission time and resources of the SSB overlap with those of other signals. To this purpose, the network may broadcast the transmission time and resource information of the SSB or indicate them through UE-specific RRC signaling.

In NR, beams may be used for transmission and reception. If reception performance of a current serving beam is degraded, a process of searching for a new beam through the so-called Beam Failure Recovery (BFR) may be performed.

Since the BFR process is not intended for declaring an error or failure of a link between the network and a UE, it may be assumed that a connection to the current serving cell is retained even if the BFR process is performed. During the BFR process, measurement of different beams (which may be expressed in terms of CSI-RS port or Synchronization Signal Block (SSB) index) configured by the network may be performed, and the best beam for the corresponding UE may be selected. The UE may perform the BFR process in a way that it performs an RACH process associated with a beam yielding a good measurement result.

Now, a transmission configuration indicator (hereinafter, TCI) state will be described. The TCI state may be configured for each CORESET of a control channel, and may determine a parameter for determining an RX beam of the UE, based on the TCI state.

For each DL BWP of a serving cell, a UE may be configured for three or fewer CORESETs. Also, a UE may receive the following information for each CORESET.

QCL will be described. If a characteristic of a channel through which a symbol on one antenna port is conveyed can be inferred from a characteristic of a channel through which a symbol on the other antenna port is conveyed, the two antenna ports are said to be quasi co-located (QCLed). For example, when two signals A and B are transmitted from the same transmission antenna array to which the same/similar spatial filter is applied, the two signals may go through the same/similar channel state. From a perspective of a receiver, upon receiving one of the two signals, another signal may be detected by using a channel characteristic of the received signal.

In this sense, when it is said that the signals A and B are quasi co-located (QCLed), it may mean that the signals A and B have went through a similar channel condition, and thus channel information estimated to detect the signal A is also useful to detect the signal B. Herein, the channel condition may be defined according to, for example, a Doppler shift, a Doppler spread, an average delay, a delay spread, a spatial reception parameter, or the like.

A 'TCI-State' parameter associates one or two downlink reference signals to corresponding QCL types (QCL types A, B, C, and D, see Table <NUM>).

Each 'TCI-State' may include a parameter for configuring a QCL relation between one or two downlink reference signals and a DM-RS port of a PDSCH (or PDDCH) or a CSI-RS port of a CSI-RS resource.

Meanwhile, for each DL BWP configured to a UE in one serving cell, the UE may be provided with <NUM> (or less) search space sets. For each search space set, the UE may be provided with at least one of the following information.

<NUM>) search space set index s (<NUM>≤s<<NUM>), <NUM>) an association between a CORESET p and the search space set s, <NUM>) a PDCCH monitoring periodicity and a PDCCH monitoring offset (slot unit), <NUM>) a PDCCH monitoring pattern within a slot (e.g., indicating a first symbol of a CORSET in a slot for PDCCH monitoring), <NUM>) the number of slots in which the search space set s exists, <NUM>) the number of PDCCH candidates per CCE aggregation level, <NUM>) information indicating whether the search space set s is CSS or USS.

In the NR, a CORESET#<NUM> may be configured by a PBCH (or a UE-dedicated signaling for handover or a PSCell configuration or a BWP configuration). A search space (SS) set#<NUM> configured by the PBCH may have monitoring offsets (e.g., a slot offset, a symbol offset) different for each associated SSB. This may be required to minimize a search space occasion to be monitored by the UE. Alternatively, this may be required to provide a beam sweeping control/data region capable of performing control/data transmission based on each beam so that communication with the UE is persistently performed in a situation where a best beam of the UE changes dynamically.

<FIG> illustrates physical channels and typical signal transmission.

Referring to <FIG>, in a wireless communication system, a UE receives information from a BS through a downlink (DL), and the UE transmits information to the BS through an uplink (UL). The information transmitted/received by the BS and the UE includes data and a variety of control information, and there are various physical channels according to a type/purpose of the information transmitted/received by the BS and the UE.

The UE which is powered on again in a power-off state or which newly enters a cell performs an initial cell search operation such as adjusting synchronization with the BS or the like (S11). To this end, the UE receives a primary synchronization channel (PSCH) and a secondary synchronization channel (SSCH) from the BS to adjust synchronization with the BS, and acquire information such as a cell identity (ID) or the like. In addition, the UE may receive a physical broadcast channel (PBCH) from the BS to acquire broadcasting information in the cell. In addition, the UE may receive a downlink reference signal (DL RS) in an initial cell search step to identify a downlink channel state.

Upon completing the initial cell search, the UE may receive a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) corresponding thereto to acquire more specific system information (S12).

Thereafter, the UE may perform a random access procedure to complete an access to the BS (S13 - S16). Specifically, the UE may transmit a preamble through a physical random access channel (PRACH) (S13), and may receive a random access response (RAR) for the preamble through a PDCCH and a PDSCH corresponding thereto (S14). Thereafter, the UE may transmit a physical uplink shared channel (PUSCH) by using scheduling information in the RAR (S15), and may perform a contention resolution procedure similarly to the PDCCH and the PDSCH corresponding thereto (S16).

After performing the aforementioned procedure, the UE may perform PDCCH/PDSCH reception (S17) and PUSCH/physical uplink control channel (PUCCH) transmission (S18) as a typical uplink/downlink signal transmission procedure. Control information transmitted by the UE to the BS is referred to as uplink control information (UCI). The UCI includes hybrid automatic repeat and request (HARQ) acknowledgement (ACK)/negative-ACK (NACK), scheduling request (SR), channel state information (CSI), or the like. The CSI includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indication (RI), or the like. In general, the UCI is transmitted through the PUCCH. However, when control information and data are to be transmitted simultaneously, the UCI may be transmitted through the PUSCH. In addition, the UE may aperiodically transmit the UCI through the PUSCH according to a request/instruction of a network.

In order to enable reasonable battery consumption when bandwidth adaptation (BA) is configured, only one uplink BWP and one downlink BWP or only one downlink/uplink BWP pair for each uplink carrier may be activated at once in an active serving cell, and all other BWPs configured in the UE are deactivated. In the deactivated BWPs, the UE does not monitor the PDCCH, and does not perform transmission on the PUCCH, PRACH, and UL-SCH.

For the BA, RX and TX bandwidths of the UE are not necessarily as wide as a bandwidth of a cell, and may be adjusted. That is, it may be commanded such that a width is changed (e.g., reduced for a period of low activity for power saving), a position in a frequency domain is moved (e.g., to increase scheduling flexibility), and a subcarrier spacing is changed (e.g., to allow different services). A subset of the entire cell bandwidth of a cell is referred to as a bandwidth part (BWP), and the BA is acquired by configuring BWP(s) to the UE and by notifying the UE about a currently active BWP among configured BWPs. When the BA is configured, the UE only needs to monitor the PDCCH on one active BWP. That is, there is no need to monitor the PDCCH on the entire downlink frequency of the cell. A BWP inactive timer (independent of the aforementioned DRX inactive timer) is used to switch an active BWP to a default BWP. That is, the timer restarts when PDCCH decoding is successful, and switching to the default BWP occurs when the timer expires.

<FIG> illustrates a scenario in which three different bandwidth parts are configured.

<FIG> shows an example in which BWP<NUM>, BWP<NUM>, and BWP<NUM> are configured on a time-frequency resource. The BWP<NUM> may have a width of <NUM> and a subcarrier spacing of <NUM>. The BWP<NUM> may have a width of <NUM> and a subcarrier spacing of <NUM>. The BWP<NUM> may have a width of <NUM> and a subcarrier spacing of <NUM>. In other words, each BWP may have a different width and/or a different subcarrier spacing.

Now, discontinuous reception (DRX) will be described.

Referring to <FIG>, the DRX cycle includes an 'on duration (hereinafter, also referred to as a 'DRX-on duration') and an 'opportunity for DRX'. The DRX cycle defines a time interval in which the on-duration is cyclically repeated. The on-duration indicates a time duration in which a UE performs monitoring to receive a PDCCH. If DRX is configured, the UE performs PDCCH monitoring during the 'on-duration'. If there is a PDCCH successfully detected during the PDCCH monitoring, the UE operates an inactivity timer and maintains an awake state. On the other hand, if there is no PDCCH successfully detected during the PDCCH monitoring, the UE enters a sleep state after the 'on-duration' ends.

Table <NUM> shows a UE procedure related to DRX (RRC_CONNECTED state). Referring to Table <NUM>, DRX configuration information may be received through higher layer (e.g., RRC) signaling. Whether DRX is ON or OFF may be controlled by a DRX command of a MAC layer. If the DRX is configured, PDCCH monitoring may be performed discontinuously.

MAC-CellGroupConfig may include configuration information required to configure a medium access control (MAC) parameter for a cell group. MAC-CellGroupConfig may also include configuration information regarding DRX. For example, MAC-CellGroupConfig may include information for defining DRX as follows.

Herein, if any one of drx-OnDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerDL is operating, the UE performs PDCCH monitoring in every PDCCH occasion while maintaining an awake state.

The UE may know a starting point of a DRX cycle, a duration (duration time) of the DRX cycle, a starting point of an on-duration timer, and a duration of the on-duration timer according to a DRX configuration. Thereafter, the UE attempts reception/detection for scheduling information (i.e., PDCCH) within the on-duration of each DRX cycle (this may be represented that scheduling information is monitored).

If the scheduling information (PDCCH) is detected within the on-duration of the DRX cycle (DRX-on duration), an inactivity timer is activated, and detection is attempted for another scheduling information during a given inactivity timer duration (a time duration in which the inactivity timer runs). In this case, the on-duration and the inactivity timer duration in which the UE performs the signal reception/detection operation may be together referred to as an active time. If the scheduling information is not detected in the on-duration, only the on-duration may be the active time.

When the inactivity timer ends without reception/detection of an additional signal (a control signal or data), the UE does not perform scheduling information and corresponding DL reception/UL transmission until an on-duration of a next DRX cycle (a DRX on duration) starts after the inactivity timer ends.

A duration adjustment of a DRX cycle, a duration adjustment of an on-duration timer/inactivity timer, or the like plays an important role in determining whether the UE sleeps. According to the setting for a corresponding parameter, the network may configure the UE to frequently sleep or continuously perform monitoring on the scheduling information. This may act as an element for determining whether power saving of the UE will be achieved.

Now, the present disclosure will be described.

Hereinafter, a PDCCH which provides power saving (PS) information will be referred to as a PS-PDCCH. That is, the PS-PDCCH may be a PDCCH notifying of the PS information. Whether to apply a power saving scheme, a method of applying the power saving scheme, or the like may be indicated to the UE by using the PS-PDCCH.

For example, a DCI format notifying of the PS information through the PS-PDCCH (for convenience, such a DCI format is referred to as a DCI format 2_6) may be received outside (other than) a DRX active time. Hereinafter, receiving the PS-PDCCH may have the equivalent meaning as receiving the DCI format (e.g., DCI format 2_6) through the PS-PDCCH.

For example, the following information may be included in the DCI format (e.g., DCI format 2_6) notifying of the PS information.

A PS-PDCCH may be used for PDCCH monitoring adaptation which is one of power saving schemes. The PDCCH monitoring adaptation may imply a scheme of adaptively skipping PDCCH monitoring or reducing PDCCH monitoring according to conditions in PDCCH monitoring occasions (which may imply a time point at which the PDCCH can be monitored) in which PDCCH monitoring is scheduled.

A PS-PDCCH for the purpose of PDCCH monitoring adaptation may be used for the purpose of search space set on/off. In this case, not only on/off for an individual search space set but also on/off for total (configured) search space sets is possible. Thus, wake-up and go-to-sleep functions may be included.

A PS-PDCCH monitoring method or the like is proposed in terms of search space (hereinafter, SS) set configuration adaptation. In general, content proposed below may be applied not only to a PS-PDCCH for the purpose of PDCCH monitoring adaptation (and/or SS set configuration adaptation) but also to PS-PDCCH reception related to power saving of other purposes.

A monitoring occasion based on a typical SS set configuration may be determined by monitoring-related parameters (e.g., monitoring periodicity, pattern, duration, offset, etc.) in the SS set configuration.

On the other hand, a monitoring occasion for a PS-PDCCH (e.g., PS-PDCCH for the wake-up purpose) may be determined by the following method. Herein, the PS-PDCCH for the wake-up purpose may imply a part of a PS-PDCCH for the SS set configuration adaptation, or may imply a PS-PDCCH configured independent of the PS-PDCCH for the SS set configuration adaptation. In addition, a wake-up indication may be transmitted independently through one PS-PDCCH, or may be transmitted by using some fields in one PS-PDCCH together with another power saving scheme.

In addition, wake-up in the present disclosure may be applied to all configured SS sets or may indicate wake-up for a specific SS set. For example, when wake-up is indicated for all configured SS sets, a UE may perform PDCCH monitoring in a PDCCH monitoring occasion specified for the all SS sets, and when wake-up is indicated for a specific SS set, PDCCH monitoring may be performed in a PSCCH monitoring occasion specified for the specific SS set.

The following option may be implemented alone or in combination. In addition, as described above, a PS-PDCCH indicating adaptation for an SS set configuration may operate as a PS-PDCCH for the wake-up or go-to-sleep purpose. For example, among monitoring occasions of the PS-PDCCH performing adaptation for the SS set configuration, a monitoring occasion located temporally first in an on-duration of a DRX operation may be interpreted for the wake-up purpose.

A monitoring occasion for a wake-up PS-PDCCH is proposed below, and a monitoring-related parameter may be configured in a PDCCH for power saving other than wake-up by the existing SS set configuration or the like.

If the PS-PDCCH for the wake-up purpose is a part of the PS-PDCCH for SS set configuration adaptation, the wake-up PS-PDCCH may imply a PS-PDCCH transmitted in some monitoring occasions among monitoring occasions of an SS set which monitors the SS set configuration adaptation PS-PDCCH.

A network may use a PS-PDCCH to indicate whether a UE will perform PDCCH monitoring in a corresponding DRX cycle (for all SS set(s) or specific SS set(s)). In this case, a monitoring occasion of a (wake-up) PS-PDCCH may be determined based on an offset with an on-duration (e.g., a DRX-on duration). For example, assuming that a monitoring occasion is located in a slot before (or after) a specific slot from a starting slot of an on-duration, the specific slot may be determined based on an offset value. Specifically, the specific slot may be directly indicated by the offset value, or the specific slot may be indirectly indicated such that monitoring is performed only in a monitoring occasion located in a specific time duration which comes after a slot indicated by the offset value. This will be described below in greater detail.

The offset value may be predefined, or may be indicated by the network through higher layer signaling (e.g., RRC signaling) or the like.

The aforementioned option <NUM>) may imply that a monitoring occasion for a PS-PDCCH (for the wake-up purpose) is configured independently, even if a monitoring occasion is configured by an SS set configuration for a PS-PDCCH.

The monitoring occasion of the PS-PDCCH (for notifying of whether wake-up is achieved) may be located in a plurality of slots consecutive from a monitoring occasion location designated by the aforementioned offset (or designed by a specific period, e.g., <NUM> slots, <NUM> slots, etc.). This may be used to increase a detection probability of the wake-up PS-PDCCH. Increasing of the detection probability may imply that DCI of the same content is repeatedly transmitted in a state of assuming the same TCI state, or may include a case where the DCI of the same content is transmitted in association with different TCI states.

In addition, the above description may imply that the PS-PDCCH for the wake-up purpose is monitored only in some of configured monitoring occasions even if monitoring occasions are designated by a monitoring periodicity, offset, or the like in the SS set configuration for the PS-PDCCH.

In a case where the SS set configuration is also indicated for the PS-PDCCH for the wake-up purpose or an SS set configuration which monitors a PS-PDCCH indicating adaptation for an SS set configuration is indicated and in a case where a monitoring occasion is determined by parameters (e.g., monitoring periodicity, offset, etc.) in the configuration, regarding the PS-PDCCH for the wake-up purpose and associated with a DRX operation, a monitoring occasion for the PS-PDCCH for the wake-up purpose may be determined by the SS set configuration (otherwise, in a case where the DRX operation is not applied or in case of a monitoring occasion of the SS set after the wake-up, the monitoring occasion may be determined by a PS-PDCCH configuration, which may be used for on/off, configuration change, or the like for the configured SS set). For example, monitoring on the PS-PDCCH for the wake-up purpose may start in a monitoring occasion nearest to a DRX-on duration among monitoring occasions based on the SS set configuration. In this case, the nearest monitoring occasion may imply the nearest monitoring occasion among monitoring occasions before the start of the on-duration, or may imply the nearest monitoring occasion among monitoring occasions after the start of the on-duration.

Alternatively, to ensure a processing time or the like for the PDCCH, the network may configure a specific offset (in this case, the offset may be applied before or after an on-duration starting point), and a monitoring occasion nearest from the offset may be defined as a starting point of PS-PDCCH monitoring.

This may be interpreted as a method of defining a monitoring starting point of a corresponding SS set in each DRX cycle of a DRX operation when the PS-PDCCH plays a role of not only wake-up but also SS set configuration adaptation (this may be also applied to other options). In addition, in this case, it may be assumed that an initial monitoring occasion of each DRX cycle is used for the wake-up purpose.

Whether to wake up may be determined with monitoring on the existing SS set without having to additionally define a PS-PDCCH for wake-up. For example, a network may configure a specific SS set for the wake-up purpose among SS sets configured in a conventional manner. In this case, a UE may perform only monitoring on the SS set in an on-duration of each DRX cycle. Thereafter, upon detecting a PDCCH in the SS set, monitoring on another SS set configured in a corresponding active BWP may start. That is, a representative SS set may be configured by the network, and whether to monitor another SS set may be determined (or assumed to be determined) by the UE according to whether the PDCCH is detected in the representative SS set.

A network may be configured to use one or a plurality of the existing SS sets for the purpose of wake-up PS-PDCCH monitoring. When monitoring on a corresponding SS set is performed in an on-duration of a DRX operation, a UE may perform monitoring on a PDCCH designated on an SS set configuration (e.g., a PDCCH designated depending on RNTI, DCI type) and a wake-up PS-PDCCH together. This may be implemented in such a manner that a configured PDCCH and a wake-up PS-PDCCH are monitored in all monitoring occasions or only a PS-PDCCH is monitored in a specific monitoring occasion (e.g., a monitoring occasion existing in a specific range from an on-duration starting point, a designed number of monitoring occasions from the on-duration starting point).

In addition, if both the existing configured PDCCH and the wake-up PS-PDCCH are monitored, it may be interpreted that detection of the existing configured PDCCH indicates wake-up. In this case, upon detecting one of the PS-PDCCH and the existing configured PDCCH, the UE may perform monitoring on another SS set.

Alternatively, the existing configured PDCCH may imply wake-up for all configured SS sets, and the wake-up PDCCH may imply wake-up for specific SS set(s).

In order to decrease complexity in this operation, it may be assumed that a size of DCI of the PS-PDCCH is equal to that of DCI monitored in a corresponding SS set. In this case, the wake-up PS-PDCCH and DCI configured to be monitored in the SS set may be identified by RNTI or the like.

A PS-PDCCH may be used for not only wake-up but also adaptation for a monitoring operation of a PDCCH. For example, the PS-PDCCH for PDCCH monitoring adaptation may be used for dynamic adaptation of an SS set configuration. As described above, the SS set configuration adaptation may dynamically configure on/off for each SS set, and if associated with a DRX operation, a first monitoring occasion (of an SS set adaptation PS-PDCCH) in each DRX cycle may operate as wake-up or go-to-sleep. The present disclosure proposes a method for implementing this.

The SS set adaptation PS-PDCCH may be used for the GTS purpose.

If the PS-PDCCH for the GTS purpose (without additional wake-up) operates in association with a DRX operation, the UE may perform monitoring on configured SS sets in a DRX on-duration, and may be indicated to turn specific SS set(s) off by a PS-PDCCH playing a role of GTS. Herein, the GTS may imply an operation result of the PS-PDCCH, and an actual PS-PDCCH may be an SS set adaptation PS-PDCCH detected in a monitoring occasion of an SS set for SS set adaptation.

The following drawings were created to explain a specific example of the present specification. The names of specific devices described in the drawings or the names of specific signals/messages/fields are presented by way of example, so that the technical features of the present specification are not limited to the specific names used in the following drawings.

<FIG> exemplifies reception of a PS-PDCCH used for GTS and an operation of a UE according thereto. Referring to <FIG>, the UE may receive/detect a PS-PDCCH for GTS while monitoring search space (SS) sets configured in the DRX on-duration. For example, the PS-PDCCH may indicate monitoring off for search space #<NUM> among search spaces #<NUM> and <NUM>.

Then, the UE may skip monitoring for search space #<NUM> after the PS-PDCCH.

Since the GTS implies a monitoring skip for the SS set, disadvantageously, it is difficult to cope with upon generation of data to be transmitted to a corresponding UE in a monitoring skip duration. To solve this, the following method may be taken into account.

Method <NUM>) If monitoring of specific SS set(s) is skipped by an SS set adaptation PS-PDCCH, a duration to be skipped may be predefined or may be indicated by a network. For example, a GTS timer may be configured, and monitoring on the SS set(s) may be resumed if this timer expires.

Method <NUM>) If monitoring of specific SS set(s) is skipped by an SS set adaptation PS-PDCCH, monitoring on the SS set adaptation PS-PDCCH may be continuously maintained. This implies that wake-up for SS set(s) of which monitoring is being skipped may be indicated by using the SS set adaptation PS-PDCCH. In this case, a monitoring configuration for the SS set adaptation PS-PDCCH may conform to a configuration for the existing SS set adaptation PS-PDCCH, or a configuration at a specific condition may be predefined or configured additionally. Additionally, the method <NUM> may also be applied limitedly only when monitoring of all SS sets configured by the GTS is skipped.

The SS set adaptation PS-PDCCH may be generally used for the purpose of dynamic adaptation for a SS set configuration. This may imply that the aforementioned PS-PDCCH for the wake-up purpose or GTS purpose is part of the PS-PDCCH for the SS set configuration adaptation purpose. That is, the PS-PDCCH for the SS set configuration adaptation purpose may be used for the wake-up or GTS purpose according to a configuration in DCI.

On/off of SS set monitoring may be performed by the following methods.

A PS-PDCCH may indicate whether to perform monitoring on a configured SS set, and may be implemented in the following manner.

<FIG> illustrates a method for monitoring a physical downlink control channel (PDCCH) of a UE.

Referring to <FIG>, the UE monitors a PS-PDCCH that notifies power saving (PS) information in a discontinuous reception (DRX)-on duration (S100).

The UE performs PDCCH monitoring in the DRX-on duration based on the detected PS-PDCCH (S200).

The PS-PDCCH includes information informing a specific search space set (or a specific search space) among a plurality of search space sets configured for the DRX-on duration.

The PS-PDCCH includes a bitmap informing the specific search space set.

The network provides the UE with a higher layer signal informing a predetermined number of search space sets to which PDCCH monitoring on/off can be applied among a plurality of search space sets configured for the DRX-on duration. Thereafter, a bitmap informing the specific search space set among the predetermined number of search space sets is provided to the UE through the PS-PDCCH. The number of bits of the bitmap may be determined based on the predetermined number. For example, if the predetermined number of search space sets is four, it may be determined as <NUM> bits or as <NUM> bits.

The UE monitors the PDCCH in search spaces other than the specific search space set among the plurality of search space sets. That is, PDCCH monitoring is skipped in the specific search space set.

A time interval for skipping the PDCCH monitoring in the specific search space set may be informed or predetermined by the network. For example, a timer (referred to as a GTS timer) may be set by the network, and when the GTS timer expires, monitoring of the specific search space set may be resumed.

In the time interval for skipping the PDCCH monitoring, the UE maintains monitoring for another PS-PDCCH. Here, the another PS-PDCCH may be a PS-PDCCH including information indicating to the UE to wake up for the specific search space set. This means that a search space set for receiving the PS-PDCCH informing a wake-up indication is continuously monitored (not sleep) despite the GTS.

The PS-PDCCH may further include a field indicating wake-up of the UE.

A time point at which PDCCH monitoring based on PS-PDCCH is applied may be determined to be the same as a minimum applicable delay value applied to cross-slot scheduling. For example, let assume that PDCCH and PDSCH are received on a carrier to which the same numerology is applied. When the DCI (the PDCCH) scheduling the PDSCH is received in slot n, if the PDSCH scheduled by the DCI can be allocated only after slot n+K0, the KO may be referred to as a minimum applicable delay. When this minimum applicable KO is, for example, <NUM> slots, the time of applying the PDCCH monitoring based on the PS-PDCCH (that is, the application time of the PS-PDCCH indicating SS set adaptation) can also be assumed to be <NUM> slots later from the time of receiving the PS-PDCCH (DCI).

The network may provide the UE with a higher layer signal indicating whether to activate or deactivate the PDCCH monitoring skip in the search space indicated by the PS-PDCCH. The UE may skip PDCCH monitoring in the search space indicated by the PS-PDCCH only when the higher layer signal informs the activation (i.e., indicates that PDCCH monitoring can be skipped).

<FIG> illustrates an operation method between a network and a UE.

Referring to <FIG>, the network provides a configuration of search space sets to which PDCCH monitoring on/off can be applied to the UE (S171).

The UE receives a PS-PDCCH including a bitmap indicating a specific search space set among the search space sets (S172), and in the DRX on duration, monitor the PDCCH in the remaining search spaces except for the specific search space set among the search space sets (S173). As a result, it can be seen that the PS-PDCCH serves to inform go-to-sleep (GTS) for the specific search space set.

From a network point of view, after transmitting a PS-PDCCH indicating power saving (PS) information in a discontinuous reception (DRX)-on duration (e.g., after transmitting a PS-PDCCH including a bitmap indicating a specific search space set among the search space sets), the network may transmit the PDCCH, to the UE, in the DRX-on duration based on the PS-PDCCH (e.g., for the UE, the network may transmit the PDCCH in the remaining search spaces except for the specific search space set among the search space sets).

A network may adjust a monitoring periodicity of specific SS set(s) by using a specific field in a PS-PDCCH. This may be implemented in such a manner that monitoring on part of the existing monitoring occasions is skipped or in such a manner that a monitoring periodicity is changed.

When the part of monitoring occasions is skipped, a scheme of indicating a rule for the skip (e.g., the skip of odd slots or the skip of even slots) or a scheme of indicating a skip duration may be used.

Such a scheme may also be applied to an aggregation level and the number of candidates to be monitored in each SS set.

When a PS-PDCCH for the purpose of the SS set configuration adaptation operates in a non-DRX operation as an additional operation, skipping of monitoring on all configured SS sets may be interpreted as newly defining the same operation as a DRX operation, which may cause unnecessary procedure execution of the network and the UE, a complexity increase, or the like. Therefore, it may be assumed in the present disclosure that an operation of turning on/off all configured SS sets is not performed in the non-DRX operation. This may be interpreted as a restriction for some of functions of the PS-PDCCH for the purpose of SS set configuration adaptation in the non-DRX operation.

It shall be determined from which time point a PS-PDCCH for the aforementioned PDCCH monitoring adaptation will be applied. To this end, a time point of applying the P-PDCCH may be configured by using at least one of the following methods. The methods proposed below may be implemented alone or in combination.

In addition, the following methods may be applied differently depending on the purpose of the PS-PDCCH. For example, methods <NUM>, <NUM>, and <NUM> below may be used in a PS-PDCCH for wake-up, and a method <NUM> below may be used in a PS-PDCCH for GTS.

In addition, the following methods may be applied in the same manner not only to a PS-PDCCH for PDCCH monitoring adaptation but also to a PS-PDCCH for other purposes (e.g., antenna adaptation, BWP/SCell operation, etc.). For example, in case of the antenna adaptation, a time point of applying the PS-PDCCH may be determined by adding a delay value related to antenna switching to an offset proposed below.

As a simple method, a UE may assume that power saving related content (e.g., SS set on/off, monitoring periodicity change, etc.) indicated by a PS-PDCCH is applied from a slot next to a slot in which the PS-PDCCH is received.

For example, assume that the PS-PDCCH is received in a slot n, and monitoring on all SS sets is skipped in the PS-PDCCH. In this case, the UE may skip monitoring on configured SS set(s) from a slot n+<NUM>. However, upon receiving DCI for PDSCH scheduling in the slot n, an operation of receiving the PDSCH may be performed even after the slot n. A technique of the method <NUM> also includes a technique applied from a symbol next to a CORESET which has received the PS-PDCCH, and a technique for implementing this may be applied in the same manner as described above.

A time point of applying a PS-PDCCH may be determined based on PDCCH decoding capacity of a UE. This may be effective in a sense that unnecessary buffering or the like can be reduced in an operation such as wake-up or the like. For example, when the UE requires two slots for PDCCH decoding (and TCI application), the UE may assume that a time point of applying a PS-PDCCH received in a slot n is a slot n+<NUM>.

When ACK transmission for a PS-PDCCH is introduced, a time point of applying the PS-PDCCH may be determined by considering a delay by which corresponding ACK arrives at a network. For example, when a time required when the network receives ACK for the PS-PDCCH from a time point at which a UE receives the PS-PDCCH is <NUM> slots, the UE may assume that a time point of applying the PS-PDCCH received in a slot n is a slot n+<NUM>.

Irrespective of a reception position of a PS-PDCCH in a slot, it may be assumed that information of a PS-PDCCH is applied from the slot. For example, when the present disclosure is applied to a PS-PDCCH, when an SS set of which monitoring is skipped by the PS-PDCCH is detected in a corresponding slot, and when decoding on a candidate of the skipped SS set is stopped or a PDSCH is scheduled, corresponding PDSCH reception may be skipped.

Method <NUM>. Additionally, it may be assumed that, when minimum applicable KO in cross-slot scheduling is configured, a time point of applying a PS-PDCCH for SS set adaptation is determined by an application delay of the minimum application KO. For example, it may be assumed that, when the application delay of the minimum applicable KO is <NUM> slots, a time point of applying a PS-PDCCH indicating the SS set adaptation is <NUM> slots after a time point of receiving corresponding DCI.

A network may determine whether to apply a power saving scheme by considering a traffic situation of the network, a service type of a UE, a mobility of the UE, a battery situation, or the like. These factors may change dynamically, which may imply that whether to apply the power saving scheme shall also be changeable dynamically. For this reason, the present disclosure proposes to dynamically configure whether to apply the power saving scheme, which can be implemented by using the following method.

The network may indicate a power saving scheme list and/or CORESET/SS set configuration for PS-PDCCH transmission/reception or the like to the UE. In this case, the configuration of the CORESET/SS set or the like may be indicated alone or in combination according to the power saving scheme (combination).

Whether to perform monitoring on a corresponding CORESET/SS set may be indicated by signaling such as RRC/MAC CE or the like by the network. That is, the UE may perform monitoring on a PS-PDCCH after activation of CORESET/SS set monitoring is indicated by additional RRC/MAC CE signaling, rather than performing monitoring based on only the CORESET/SS set configuration for power saving. Deactivation for monitoring may also be indicated by RRC/MAC CE signaling.

For example, the network may indicate a plurality of CORESET/SS sets capable of monitoring a PS-PDCCH through RRC signaling or the like, and may indicate a time point at which the UE performs monitoring and the CORESET/SS set to the UE through MAC CE signaling. Alternatively, CORESET/SS set candidate signaling may be indicated through a broadcast signal (e.g., system information (SIB)) to reduce a signaling overhead or the like.

<FIG> illustrates a wireless device applicable to the present specification.

The processors <NUM> may control the memory <NUM> and/or the transceivers <NUM> and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processors <NUM> may process information within the memory <NUM> to generate first information/signals and then transmit radio signals including the first information/signals through the transceivers <NUM>. In addition, the processor <NUM> may receive radio signals including second information/signals through the transceiver <NUM> and then store information obtained by processing the second information/signals in the memory <NUM>. The memory <NUM> may be connected to the processory102 and may store a variety of information related to operations of the processor <NUM>. For example, the memory <NUM> may store software code including commands for performing a part or the entirety of processes controlled by the processor <NUM> or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor <NUM> and the memory <NUM> may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver <NUM> may be connected to the processor <NUM> and transmit and/or receive radio signals through one or more antennas <NUM>. The transceiver <NUM> may include a transmitter and/or a receiver. The transceiver <NUM> may be interchangeably used with a radio frequency (RF) unit. In the present specification, the wireless device may represent a communication modem/circuit/chip.

The processor <NUM> may control the memory <NUM> and/or the transceiver <NUM> and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor <NUM> may process information within the memory <NUM> to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver <NUM>. In addition, the processor <NUM> may receive radio signals including fourth information/signals through the transceiver <NUM> and then store information obtained by processing the fourth information/signals in the memory <NUM>. The memory <NUM> may be connected to the processor <NUM> and may store a variety of information related to operations of the processor <NUM>. For example, the memory <NUM> may store software code including commands for performing a part or the entirety of processes controlled by the processor <NUM> or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor <NUM> and the memory <NUM> may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver <NUM> may be connected to the processor <NUM> and transmit and/or receive radio signals through one or more antennas <NUM>. The transceiver <NUM> may include a transmitter and/or a receiver. The transceiver <NUM> may be interchangeably used with an RF unit. In the present specification, the wireless device may represent a communication modem/circuit/chip.

For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors <NUM> and <NUM>. The one or more processors <NUM> and <NUM> may be implemented with at least one computer readable medium (CRM) including instructions to be executed by at least one processor. That is, the at least one CRM including the instructions to be executed by the at least one processor may perform operations including receiving an offset based on a starting slot of a DRX-on duration and monitoring a PS-PDCCH notifying of power saving (PS) information in a time window between the starting slot and a time based on the offset.

That is, at least one computer readable medium (CRM) including instructions based on being executed by at least one processor may perform the following steps. Monitoring a PS-PDCCH informing of power saving (PS) information in a discontinuous reception (DRX)-on duration and performing PDCCH monitoring in the DRX-on duration based on the detected PS-PDCCH. The PS-PDCCH includes information indicating a specific search space set among a plurality of search space sets configured for the DRX-on duration, and the UE monitors the PDCCH in remaining search spaces other than the specific search space set among the plurality of search space sets.

In addition, the one or more memories <NUM> and <NUM> may be connected to the one or more processors <NUM> and <NUM> through various technologies such as wired or wireless connection.

In addition, the one or more processors <NUM> and <NUM> may perform control so that the one or more transceivers <NUM> and <NUM> may receive user data, control information, or radio signals from one or more other devices. In addition, the one or more transceivers <NUM> and <NUM> may be connected to the one or more antennas <NUM> and <NUM> and the one or more transceivers <NUM> and <NUM> may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, through the one or more antennas <NUM> and <NUM>.

<FIG> shows an example of a structure of a signal processing module. Herein, signal processing may be performed in the processors <NUM> and <NUM> of <FIG>.

Referring to <FIG>, the transmitting device (e.g., a processor, the processor and a memory, or the processor and a transceiver) in a UE or BS may include a scrambler <NUM>, a modulator <NUM>, a layer mapper <NUM>, an antenna port mapper <NUM>, a resource block mapper <NUM>, and a signal generator <NUM>.

The transmitting device can transmit one or more codewords. Coded bits in each codeword are scrambled by the corresponding scrambler <NUM> and transmitted over a physical channel. A codeword may be referred to as a data string and may be equivalent to a transport block which is a data block provided by the MAC layer.

Scrambled bits are modulated into complex-valued modulation symbols by the corresponding modulator <NUM>. The modulator <NUM> can modulate the scrambled bits according to a modulation scheme to arrange complex-valued modulation symbols representing positions on a signal constellation. The modulation scheme is not limited and m-PSK (m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude Modulation) may be used to modulate the coded data. The modulator may be referred to as a modulation mapper.

The complex-valued modulation symbols can be mapped to one or more transport layers by the layer mapper <NUM>. Complex-valued modulation symbols on each layer can be mapped by the antenna port mapper <NUM> for transmission on an antenna port.

Each resource block mapper <NUM> can map complex-valued modulation symbols with respect to each antenna port to appropriate resource elements in a virtual resource block allocated for transmission. The resource block mapper can map the virtual resource block to a physical resource block according to an appropriate mapping scheme. The resource block mapper <NUM> can allocate complex-valued modulation symbols with respect to each antenna port to appropriate subcarriers and multiplex the complex-valued modulation symbols according to a user.

Signal generator <NUM> can modulate complex-valued modulation symbols with respect to each antenna port, that is, antenna-specific symbols, according to a specific modulation scheme, for example, OFDM (Orthogonal Frequency Division Multiplexing), to generate a complex-valued time domain OFDM symbol signal. The signal generator can perform IFFT (Inverse Fast Fourier Transform) on the antenna-specific symbols, and a CP (cyclic Prefix) can be inserted into time domain symbols on which IFFT has been performed. OFDM symbols are subjected to digital-analog conversion and frequency up-conversion and then transmitted to the receiving device through each transmission antenna. The signal generator may include an IFFT module, a CP inserting unit, a digital-to-analog converter (DAC) and a frequency upconverter.

<FIG> shows another example of a structure of a signal processing module in a transmitting device. Herein, signal processing may be performed in a processor of a UE/BS, such as the processors <NUM> and <NUM> of <FIG>.

Referring to <FIG>, the transmitting device (e.g., a processor, the processor and a memory, or the processor and a transceiver) in the UE or the BS may include a scrambler <NUM>, a modulator <NUM>, a layer mapper <NUM>, a precoder <NUM>, a resource block mapper <NUM>, and a signal generator <NUM>.

The transmitting device can scramble coded bits in a codeword by the corresponding scrambler <NUM> and then transmit the scrambled coded bits through a physical channel.

Scrambled bits are modulated into complex-valued modulation symbols by the corresponding modulator <NUM>. The modulator can modulate the scrambled bits according to a predetermined modulation scheme to arrange complex-valued modulation symbols representing positions on a signal constellation. The modulation scheme is not limited and pi/<NUM>-BPSK (pi/<NUM>-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude Modulation) may be used to modulate the coded data.

The complex-valued modulation symbols can be mapped to one or more transport layers by the layer mapper <NUM>.

Complex-valued modulation symbols on each layer can be precoded by the precoder <NUM> for transmission on an antenna port. Here, the precoder may perform transform precoding on the complex-valued modulation symbols and then perform precoding. Alternatively, the precoder may perform precoding without performing transform precoding. The precoder <NUM> can process the complex-valued modulation symbols according to MIMO using multiple transmission antennas to output antenna-specific symbols and distribute the antenna-specific symbols to the corresponding resource block mapper <NUM>. An output z of the precoder <NUM> can be obtained by multiplying an output y of the layer mapper <NUM> by an N x M precoding matrix W. Here, N is the number of antenna ports and M is the number of layers.

Each resource block mapper <NUM> maps complex-valued modulation symbols with respect to each antenna port to appropriate resource elements in a virtual resource block allocated for transmission.

The resource block mapper <NUM> can allocate complex-valued modulation symbols to appropriate subcarriers and multiplex the complex-valued modulation symbols according to a user.

Signal generator <NUM> can modulate complex-valued modulation symbols according to a specific modulation scheme, for example, OFDM, to generate a complex-valued time domain OFDM symbol signal. The signal generator <NUM> can perform IFFT (Inverse Fast Fourier Transform) on antenna-specific symbols, and a CP (cyclic Prefix) can be inserted into time domain symbols on which IFFT has been performed. OFDM symbols are subjected to digital-analog conversion and frequency up-conversion and then transmitted to the receiving device through each transmission antenna. The signal generator <NUM> may include an IFFT module, a CP inserting unit, a digital-to-analog converter (DAC) and a frequency upconverter.

The signal processing procedure of the receiving device may be reverse to the signal processing procedure of the transmitting device. Specifically, the processor of the transmitting device decodes and demodulates RF signals received through antenna ports of the transceiver. The receiving device may include a plurality of reception antennas, and signals received through the reception antennas are restored to baseband signals, and then multiplexed and demodulated according to MIMO to be restored to a data string intended to be transmitted by the transmitting device. The receiving device may include a signal restoration unit that restores received signals to baseband signals, a multiplexer for combining and multiplexing received signals, and a channel demodulator for demodulating multiplexed signal strings into corresponding codewords. The signal restoration unit, the multiplexer and the channel demodulator may be configured as an integrated module or independent modules for executing functions thereof. More specifically, the signal restoration unit may include an analog-to-digital converter (ADC) for converting an analog signal into a digital signal, a CP removal unit that removes a CP from the digital signal, an FET module for applying FFT (fast Fourier transform) to the signal from which the CP has been removed to output frequency domain symbols, and a resource element demapper/equalizer for restoring the frequency domain symbols to antenna-specific symbols. The antenna-specific symbols are restored to transport layers by the multiplexer and the transport layers are restored by the channel demodulator to codewords intended to be transmitted by the transmitting device.

<FIG> illustrates an example of a wireless communication device according to an implementation example of the present disclosure.

Referring to <FIG>, the wireless communication device, for example, a terminal may include at least one of a processor <NUM> such as a digital signal processor (DSP) or a microprocessor, a transceiver <NUM>, a power management module <NUM>, an antenna <NUM>, a battery <NUM>, a display <NUM>, a keypad <NUM>, a global positioning system (GPS) chip <NUM>, a sensor <NUM>, a memory <NUM>, a subscriber identification module (SIM) card <NUM>, a speaker <NUM> and a microphone <NUM>. A plurality of antennas and a plurality of processors may be provided.

The processor <NUM> can implement functions, procedures and methods described in the present description. The processor <NUM> in <FIG> may be the processors <NUM> and <NUM> in <FIG>.

The memory <NUM> is connected to the processor <NUM> and stores information related to operations of the processor. The memory may be located inside or outside the processor and connected to the processor through various techniques such as wired connection and wireless connection. The memory <NUM> in <FIG> may be the memories <NUM> and <NUM> in <FIG>.

A user can input various types of information such as telephone numbers using various techniques such as pressing buttons of the keypad <NUM> or activating sound using the microphone <NUM>. The processor <NUM> can receive and process user information and execute an appropriate function such as calling using an input telephone number. In some scenarios, data can be retrieved from the SIM card <NUM> or the memory <NUM> to execute appropriate functions. In some scenarios, the processor <NUM> can display various types of information and data on the display <NUM> for user convenience.

The transceiver <NUM> is connected to the processor <NUM> and transmit and/or receive RF signals. The processor can control the transceiver in order to start communication or to transmit RF signals including various types of information or data such as voice communication data. The transceiver includes a transmitter and a receiver for transmitting and receiving RF signals. The antenna <NUM> can facilitate transmission and reception of RF signals. In some implementation examples, when the transceiver receives an RF signal, the transceiver can forward and convert the signal into a baseband frequency for processing performed by the processor. The signal can be processed through various techniques such as converting into audible or readable information to be output through the speaker <NUM>. The transceiver in <FIG> may be the transceivers <NUM> and <NUM> in <FIG>.

Although not shown in <FIG>, various components such as a camera and a universal serial bus (USB) port may be additionally included in the terminal. For example, the camera may be connected to the processor <NUM>.

<FIG> is an example of implementation with respect to the terminal and implementation examples of the present disclosure are not limited thereto. The terminal need not essentially include all the components shown in <FIG>. That is, some of the components, for example, the keypad <NUM>, the GPS chip <NUM>, the sensor <NUM> and the SIM card <NUM> may not be essential components. In this case, they may not be included in the terminal.

<FIG> shows an example of a processor <NUM>.

Referring to <FIG>, the processor <NUM> may include a control channel monitoring unit <NUM> and a data channel receiving unit <NUM>. The processor <NUM> may execute the methods described in <FIG> (from a perspective of a receiver). For example, the processor <NUM> may receive an offset based on a starting slot of a DRX-on duration, and may monitor a PS-PDCCH notifying of power saving (PS) information in a time window between the starting slot and a time based on the offset. Upon detecting/receiving a PDCCH including scheduling information in the DRX-on duration, a PDSCH may be received based on the PDCCH (or a PUSCH may be transmitted). The processor <NUM> may be an example of the processors <NUM> and <NUM> of <FIG>.

Referring to <FIG>, the processor <NUM> may include a control information/data generating module <NUM> and a transmitting module <NUM>. The processor <NUM> may execute the methods described in <FIG> (from a perspective of a transceiver). For example, the processor <NUM> may generate an offset based on a starting slot of a DRX-on duration, and then may notify a UE about it. In addition, the processor <NUM> may transmit a PS-PDCCH notifying of power saving (PS) information in a time window between the starting slot and a time based on the offset. Thereafter, a PDCCH including scheduling information may be transmitted in the DRX-on duration, and a PDSCH may be transmitted or a PUSCH may be received based on the PDCCH. The processor <NUM> may be an example of the processors <NUM> and <NUM> of <FIG>.

<FIG> shows another example of a wireless device.

Referring to <FIG>, the wireless device may include one or more processors <NUM> and <NUM>, one or more memories <NUM> and <NUM>, and one or more transceivers <NUM> and <NUM>.

The example of the wireless device described in <FIG> is different from the example of the wireless described in <FIG> in that the processors <NUM> and <NUM> and the memories <NUM> and <NUM> are separated in <FIG> whereas the memories <NUM> and <NUM> are included in the processors <NUM> and <NUM> in the example of <FIG>. That is, the processor and the memory may constitute one chipset. That is, a chipset (a device of a wireless communication system) may include a processor and a memory coupled with the processor, wherein the processor is configured to receive an offset based on a starting slot of a DRX-on duration and to monitor a PS-PDCCH notifying of PS information in a time window between the time slot and a time based on the offset.

<FIG> shows another example of a wireless device applied to the present specification. The wireless device may be implemented in various forms according to a use-case/service.

In addition, the control unit <NUM> may transmit the information stored in the memory unit <NUM> to the exterior (e.g., other communication devices) via the communication unit <NUM> through a wireless/wired interface or store, in the memory unit <NUM>, information received through the wireless/wired interface from the exterior (e.g., other communication devices) via the communication unit <NUM>.

In addition, each element, component, unit/portion, and/or module within the wireless devices <NUM> and <NUM> may further include one or more elements. For example, the control unit <NUM> may be configured by a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphical processing unit, and a memory control processor. For another example, the memory <NUM> may be configured by a Random Access Memory (RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory, a volatile memory, a non-volatile memory, and/or a combination thereof.

<FIG> illustrates a hand-held device applied to the present specification. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), or a portable computer (e.g., a notebook). The hand-held device may be referred to as a mobile station (MS), a user terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT).

Blocks <NUM> to <NUM>/140a to140c respective correspond to the blocks <NUM> to <NUM>/<NUM> of <FIG>.

In addition, the memory unit <NUM> may store input/output data/information.

For example, in the case of data communication, the I/O unit 140c may acquire information/signals (e.g., touch, text, voice, images, or video) input by a user and the acquired information/signals may be stored in the memory unit <NUM>. In addition, the communication unit <NUM> may receive radio signals from other wireless devices or the BS and then restore the received radio signals into original information/signals.

<FIG> illustrates a communication system <NUM> applied to the present specification.

Referring to <FIG>, a communication system <NUM> applied to the present specification includes wireless devices, Base Stations (BSs), and a network. Herein, the wireless devices represent devices performing communication using Radio Access Technology (RAT) (e.g., <NUM> New RAT (NR)) or Long-Term Evolution (LTE)) and may be referred to as communication/radio/<NUM> devices. The wireless devices may include, without being limited to, a robot 100a, vehicles 100b-<NUM> and 100b-<NUM>, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an Artificial Intelligence (AI) device/server <NUM>. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous vehicle, and a vehicle capable of performing communication between vehicles. Herein, the vehicles 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) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). For example, the BSs and the network may be implemented as wireless devices and a specific wireless device 200a may operate as a BS/network node with respect to other wireless devices.

In addition, 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.

Wireless communication/connections 150a, 150b, or 150c may be established between the wireless devices 100a to 100f/BS <NUM>, or BS <NUM>/BS <NUM>. Herein, the wireless communication/connections may be established through various RATs (e.g., <NUM> 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 devices and the BSs/the wireless devices may transmit/receive radio signals to/from each other through the wireless communication/connections 150a and 150b. For example, the wireless communication/connections 150a and 150b may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.

Meanwhile, the NR supports multiple numerologies (or subcarrier spacing (SCS)) for supporting diverse <NUM> services. For example, if the SCS is <NUM>, a wide area of the conventional cellular bands may be supported. If the SCS is <NUM>/<NUM>, a dense-urban, lower latency, and wider carrier bandwidth is supported. If the SCS is <NUM> or higher, a bandwidth greater than <NUM> is used in order to overcome phase noise.

An NR frequency band may be defined as a frequency range of two types (FR1, FR2). Values of the frequency range may be changed. For example, the frequency range of the two types (FR1, FR2) may be as shown below in Table <NUM>. For convenience of explanation, among the frequency ranges that are used in an NR system, FR1 may mean a "sub <NUM> range", and FR2 may mean an "above <NUM> range" and may also be referred to as a millimeter wave (mmW).

As described above, the values of the frequency ranges in the NR system may be changed. For example, as shown in Table <NUM> below, FR1 may include a band in the range of <NUM> to <NUM>. That is, FR1 may include a frequency band of at least <NUM> (or <NUM>, <NUM>, <NUM>, and so on). For example, a frequency band of at least <NUM> (or <NUM>, <NUM>, <NUM>, and so on) included in FR1 may include an unlicensed band.

<FIG> illustrates a vehicle or an autonomous vehicle applicable to the present specification. The vehicle or autonomous vehicle may be implemented by a mobile robot, a car, a train, a manned/unmanned Aerial Vehicle (AV), a ship, etc..

The blocks <NUM>/<NUM>/140a to 140d respectively correspond to the blocks <NUM>/<NUM>/<NUM> of <FIG>.

For example, the communication unit <NUM> may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the obtained data. The control unit <NUM> may control the driving unit 140a such that the vehicle or the autonomous vehicle <NUM> may move along the autonomous driving path according to the driving plan (e.g., speed/direction control). In the middle of autonomous driving, the communication unit <NUM> may aperiodically/periodically acquire recent traffic information data from the external server and acquire surrounding traffic information data from neighboring vehicles. In the middle of autonomous driving, the sensor unit 140c may obtain a vehicle state and/or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and the driving plan based on the newly obtained data/information. The communication unit <NUM> may transfer information about a vehicle position, the autonomous driving path, and/or the driving plan to the external server. The external server may predict traffic information data using AI technology, etc., based on the information collected from vehicles or autonomous vehicles and provide the predicted traffic information data to the vehicles or the autonomous vehicles.

Claim 1:
A method for monitoring a physical downlink control channel, PDCCH, of a user equipment, UE, in a wireless communication system, the method comprising:
receiving (S171) a higher layer signal informing a predetermined number of search space sets to which PDCCH monitoring on/off can be applied among a plurality of search space sets configured for a discontinuous reception-on, DRX-on, duration;
monitoring (<NUM>; S172) a PS-PDCCH notifying power saving, PS, information in the DRX-on duration; and
performing PDCCH monitoring (<NUM>; S173) in the DRX-on duration based on the PS-PDCCH,
wherein the PS-PDCCH includes a bitmap informing a specific search space set among the predetermined number of search space sets,
wherein a number of bits of the bitmap is determined based on the predetermined number,
wherein the PDCCH is monitored in search spaces other than the specific search space set among the plurality of search space sets, and
wherein the UE maintains monitoring for another PS-PDCCH in the specific search space.