User equipments, base stations and methods

Abstract

A user equipment (UE) is described. The UE comprises reception circuitry configured to receive first information configuring first set of ROs, second information configuring a second set of ROs, and third information including first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs, control circuitry configured to determine available ROs for a PRACH transmission base on the first information, the second information and the third information.

Description

[DESCRIPTION][Title of Invention]USER EQUIPMENTS, BASE STATIONS AND METHODS[Technical Field]

[0001] The present invention relates to a user equipment, a base station and a method.[Background Art]

[0002] In the 3rd Generation Partnership Project (3GPP (Registered trademark)), a radio access method and a radio network for cellular mobile communications (hereinafter, referred to as Long Term Evolution, or Evolved Universal Terrestrial Radio Access) have been studied. In LTE (Long Term Evolution), a base station device is also referred to as an evolved NodeB (eNodeB), and a terminal device is also referred to as a User Equipment (UE). LTE is a cellular communication system in which multiple areas are deployed in a cellular structure, with each of the multiple areas being covered by a base station device. A single base station device may manage multiple cells. Evolved Universal Terrestrial Radio Access is also referred as E-UTRA.

[0003] In the 3GPP, the next generation standard (New Radio: NR) has been studied in order to make a proposal to the International-Mobile-Telecommunication-2020 (IMT-2020) which is a standard for the next generation mobile communication system defined by the International Telecommunications Union (ITU). NR has been expected to satisfy a requirement considering three scenarios of enhanced Mobile BroadBand (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliable and Low Latency Communication (URLLC), in a single technology framework.

[0004] With the increase of traffic for 5G with its pervasive, network energy saving is getting one of the important techniques for environmental sustainability, to reduceenvironmental impact (greenhouse gas emissions), and for operational cost savings. Novel solutions to improve network energy savings need to be developed.[Brief Description of the Drawings]

[0005] Figure 1 is a conceptual diagram of a wireless communication system;

[0006] Figure 2 is an example showing the relationship between subcarrier-spacing configuration u, the number of OFDM symbols per slot Nslotsymb, and the CP configuration;

[0007] Figure 3 is a diagram showing an example of a method of configuring a resource grid;

[0008] Figure 4 is a diagram showing a configuration example of a resource grid 3001;

[0009] Figure 5 is a schematic block diagram showing a configuration example of the base station device;

[0010] Figure 6 is a schematic block diagram showing a configuration example of the terminal device;

[0011] Figure 7 is an example showing the higher layer parameters included in MIB,'

[0012] Figure 8 is a diagram showing a configuration example of an SS / PBCH block;

[0013] Figure 9 is a diagram showing an example of SS / PBCH block transmission for 15 kHz SCS with carrier frequencies larger than 3 GHz;

[0014] Figure 10 is a diagram showing an example of the monitoring occasion of the search-space-set;

[0015] Figure 11 is a diagram showing an example of parameter structure of RACH- ConfigCommon and RACH-ConfigGeneric,

[0016] Figure 12 is a diagram showing an example of parameter constructure of featureCombinationPreambles and featureCombinatiorr,

[0017] Figure 13 is a diagram illustrating an example of a contention-based random access (CBRA) procedure of the terminal device 1;

[0018] Figure 14 is a diagram illustrating an example of a contention-free random access (CFRA) procedure of the terminal device 1;

[0019] Figure 15 is a diagram showing an example of a table of PRACH mask index;

[0020] Figure 16 is a diagram illustrating an example of allocation of SSB indexes to ROs;

[0021] Figure 17 is a diagram showing an example of adaptation of PRACH resources;

[0022] Figure 18 is a diagram showing an example of parameter structure of RACH- ConfigCommon2 configuring the adaptive PRACH resources;

[0023] Figure 19 is a diagram showing an example of a table of the association period mask index;

[0024] Figure 20 is a diagram showing an example of a method for a terminal device 1;

[0025] Figure 21 is a diagram showing an example of a method for a base station 3.[Description of Embodiments]

[0026] A user equipment (UE) is described. The UE may comprise reception circuitry configured to receive first information configuring first set of random access occasions (ROs), to receive second information configuring a second set of ROs, and to receive third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first setof ROs. The UE may comprise control circuitry configured to determine, in case that the first set of ROs is deactivated, available ROs from the second set of ROs, and to determine, in case that the first set of ROs is activated, the available ROs from the first set of ROs included in the time subset per the time periodicity and the second set of ROs. The UE may comprise transmission circuitry configured to transmit a random access preamble on a random access occasion in the available ROs.

[0027] The first parameter may show a number of association periods to indicate the time periodicity.

[0028] The second parameter may show which half or which quarter in the time periodicity the time subset is.

[0029] The reception circuitry may receive the first information, the second information and the third information by RRC signalling.

[0030] The activation of the first set of ROs may be indicated by physical downlink control channel (PDCCH).

[0031] A base station is described. The base station may comprise transmission circuitry configured to transmit first information configuring first set of random access occasions (ROs), to transmit second information configuring a second set of ROs, and to transmit third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs. The base station may comprise reception circuitry configured to monitor, in case that the first set of ROs is deactivated, a random access preamble on the second set of ROs, and to monitor, in case that the first set of ROs is activated, a random access preamble on the first set of ROs included in the time subset per the time periodicity and on the second set of ROs.

[0032] The first parameter may show a number of association periods to indicate the time periodicity.

[0033] The second parameter may show which half or which quarter in the time periodicity the time subset is.

[0034] The transmission circuitry may transmit the first information, the second information and the third information by RRC signalling.

[0035] The activation of the first set of ROs may be indicated to a terminal device by physical downlink control channel (PDCCH).

[0036] A method performed by a base station is described. The method may comprise transmitting first information configuring first set of random access occasions (ROs), transmitting second information configuring a second set of ROs, and transmitting third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs. The method may comprise monitoring, in case that the first set of ROs is deactivated, a random access preamble on the second set of ROs, and monitoring, in case that the first set of ROs is activated, a random access preamble on the first set of ROs included in the time subset per the time periodicity and on the second set of ROs.

[0037] floor (CX) may be a floor function for real number CX. For example, floor (CX) may be a function that provides the largest integer within a range that does not exceed the real number CX. ceil (DX) may be a ceiling function to a real number DX. For example, ceil (DX) may be a function that provides the smallest integer within the range not less than the real number DX. mod (EX, FX) may be a function that provides the remainder obtained by dividing EX by FX. mod (EX, FX) may be a function that providesa value which corresponds to the remainder of dividing EX by FX. It is exp (GA) = eAGX Here, e is Napier number. HX)A(IX) indicates IX to the power of HX.

[0038] In a wireless communication system according to one aspect of the present embodiment, at least OFDM (Orthogonal Frequency Division Multiplex) is used. An OFDM symbol is a unit of time domain of the OFDM. The OFDM symbol includes at least one or more subcarriers. An OFDM symbol is converted to a time-continuous signal in baseband signal generation. In downlink, at least CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplex) is used. In uplink, either CP-OFDM or DFT-s-OFDM (Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplex) is used. DFT-s-OFDM may be given by applying transform precoding to CP-OFDM. CP-OFDM is OFDM using CP (Cyclic Prefix).

[0039] The OFDM symbol may be a designation including a CP added to the OFDM symbol. That is, an OFDM symbol may be configured to include the OFDM symbol and a CP added to the OFDM symbol.

[0040] Figure 1 is a conceptual diagram of a wireless communication system. In Figure 1, the wireless communication system includes at least terminal device 1A to 1C and a base station device 3 (BS 3: Base station 3). Hereinafter, the terminal devices lAto 1C are also referred to as a terminal device 1 (UE 1: User Equipment 1).

[0041] A terminal device 1 is either in RRC_CONNECTED state or in RRC_INACTIVE state when an RRC (Radio Resource Control) connection has been established. If this is not the case, i.e. no RRC connection is established, the terminal device 1 is in RRC_IDLE state. When the terminal device 1 suspends the RRC connection, the terminal device 1 may be in RRC_INACTIVE state.

[0042] A terminal device 1 in RRC_IDLE state or a terminal device 1 in RRC_INACTIVE state may perform acquisition of system information (SI) and sending of SI request (if configured).

[0043] The BS 3 may be configured to include one or more transmission devices (or transmission points, transmission devices, reception devices, transmission points, reception points). When the BS 3 is configured by a plurality of transmission devices, each of the plurality of transmission devices may be arranged at a different position.

[0044] The BS 3 may provide one or more serving cells. A serving cell may be defined as a set of resources used for wireless communication. A serving cell is also referred to as a cell.

[0045] A serving cell may be configured to include at least one downlink component carrier (downlink carrier) and / or one uplink component carrier (uplink carrier). A serving cell may be configured to include at least two or more downlink component carriers and / or two or more uplink component carriers. A downlink component carrier and an uplink component carrier are also referred to as component carriers (carriers). The uplink component carrier can be used for sidelink communication.

[0046] For example, one resource grid may be provided for one component carrier. For example, one resource grid may be provided for one component carrier and a subcarrier-spacing configuration u. A subcarrier-spacing configuration u is also referred to as numerology. A resource grid includes Nslze’I'grid,xNRBSc subcarriers. The resource grid starts from a common resource block with index Nstart’ "grid. The common resource block with the index Nstart>"grid is also referred to as a reference point of the resource grid. The resource grid includes Nsubframe’ "Symb OFDM symbols. The subscript x indicates the transmission direction and indicates either downlink or uplink. One resource grid isprovided for an antenna port p, a subcarrier-spacing configuration u, and a transmission direction x. The resource grid may be applied to downlink, uplink and / or sidelink.

[0047] Resource grid is also referred to as carrier.

[0048] Nslze’ "grid, and Nstart’ "grid are given based at least on an RRC parameter (e.g. referred to as RRC parameter CarrierBandwidth). The RRC parameter is used to define one or more SCS (SubCarrier-Spacing) specific carriers. One resource grid corresponds to one SCS specific carrier. One component carrier may comprise one or more SCS specific carriers. The SCS specific carrier may be included in a system information block (SIB). For each SCS specific carrier, a subcarrier-spacing configuration u may be provided.

[0049] Figure 2 is an example showing the relationship between subcarrier-spacing configuration u, the number of OFDM symbols per slotNslotsymb, and the CP configuration. In Figure 2A, for example, when the subcarrier-spacing configuration u is set to 2 and the CP configuration is set to normal CP (normal cyclic prefix), NslotSymb = 14, Nframe’ “slot -40, Nsubframe>"slot = 4. Further, in Figure 2B, for example, when the subcarrier-spacing configuration u is set to 2 and the CP configuration is set to an extended CP (extended cyclic prefix), Nslotsymb = 12, Nframe’ "slot = 40, Nsubframe’ “slot = 4. The subcarrier-spacing configuration u may be applied to downlink, uplink and / or sidelink.

[0050] In the wireless communication system, a time unit Tomay be used to represent the length of the time domain. The time unit Tcis Tc= 1 / (dfmax * Nf). It is dfmax = 480 kHz. It is Nf = 4096. The constant k is k = dfmax* Nf / (dfrefNf,ref) = 64. dfref is 15 kHz. Nf, ref is 2048.

[0051] Transmission of signals in the downlink and / or transmission of signals in the uplink and / or transmission of signals in the sidelink may be organized into radio frames(system frames, frames) of length Tf. It is Tf = (dfmaxNf / 100) * Ts= 10 ms. One radio frame is configured to include ten subframes. The subframe length is Tsf = (dfmaxNf / 1000) Ts= 1 ms. The number of OFDM symbols per subframe is Nsubframe’Hsymb = Nsl0tSymbNSubframe’ "slot-

[0052] For a subcarrier-spacing configuration u, the number of slots included in a subframe and indexes may be given. For example, slot index n"smay be given in ascending order with an integer value ranging from 0 to Nsubframe,i'siot -1 in a subframe. For subcarrier-spacing configuration u, the number of slots included in a radio frame and indexes of slots included in the radio frame may be given. Also, the slot index n f may be given in ascending order with an integer value ranging from 0 to Nframe,!'siot -1 in the radio frame. Consecutive Nslotsymb OFDM symbols may be included in one slot. It is Nsl0tsymb = 14.

[0053] Figure 3 is a diagram showing an example of a method of configuring a resource grid. The horizontal axis in Figure 3 indicates frequency domain. Figure 3 shows a configuration example of a resource grid of subcarrier-spacing configuration M = MI in the component carrier 300 and a configuration example of a resource grid of subcarrierspacing configuration u = ui in a component carrier. One or more subcarrier-spacing configuration may be set for a component carrier. Although it is assumed in Figure 3 that u\ = «2-l, various aspects of this embodiment are not limited to the condition of u\ = ui- 1.

[0054] The component carrier 300 is a band having a predetermined width in the frequency domain.

[0055] Point 3000 is an identifier for identifying a subcarrier. Point 3000 is also referred to as point A. The common resource block (CRB) set 3100 is a set of common resource blocks for the subcarrier-spacing configuration MI.

[0056] Among the common resource block-set 3100, the common resource block including the point 3000 (the block indicated by the upper right diagonal line in Figure 3) is also referred to as a reference point of the common resource block-set 3100. The reference point of the common resource block-set 3100 may be a common resource block with index 0 in the common resource block-set 3100.

[0057] The offset 3011 is an offset from the reference point of the common resource block-set 3100 to the reference point of the resource grid 3001. The offset 3011 is indicated by the number of common resource blocks which is relative to the subcarrierspacing configuration I. The resource grid 3001 includes Nslze,"gridi^ common resource blocks starting from the reference point of the resource grid 3001.

[0058] The offset 3013 is an offset from the reference point of the resource grid 3001 to the reference point (Nstart> MBWP, / i) of the BWP (Bandwidth Part) 3003 of the index zl.

[0059] Common resource block-set 3200 is a set of common resource blocks with respect to subcarrier-spacing configuration U2.

[0060] A common resource block including the point 3000 (a block indicated by an upper left diagonal line in Figure 3) in the common resource block-set 3200 is also referred to as a reference point of the common resource block-set 3200. The reference point of the common resource block-set 3200 may be a common resource block with index 0 in the common resource block-set 3200.

[0061] The offset 3012 is an offset from the reference point of the common resource block-set 3200 to the reference point of the resource grid 3002. The offset 3012 isindicated by the number of common resource blocks for subcarrier-spacing configuration u - U2. The resource grid 3002 includes Nslze’“grid2,.-t common resource blocks starting from the reference point of the resource grid 3002.

[0062] The offset 3014 is an offset from the reference point of the resource grid 3002 to the reference point (Nstart’wBWP,a) of the BWP 3004 with index i2.

[0063] Figure 4 is a diagram showing a configuration example of a resource grid 3001. In the resource grid of Figure 4, the horizontal axis indicates OFDM symbol index Zsym, and the vertical axis indicates the subcarrier index ksc. The resource grid 3001 includes Nsize,ugrid1xNRBscsubcarriers, and includes Nsubframes’usymb OFDM symbols. A resource specified by the subcarrier index ksc and the OFDM symbol index Zsymin a resource grid is also referred to as a resource element (RE).

[0064] A resource block (RB) includes NRBSCconsecutive subcarriers. A resource block is a generic name of a common resource block, a physical resource block (PRB), and a virtual resource block (VRB). It is NRBSC= 12.

[0065] A resource block unit is a set of resources that corresponds to one OFDM symbol in one resource block. That is, one resource block unit includes 12 resource elements which corresponds to one OFDM symbol in one resource block.

[0066] Common resource blocks for a subcarrier-spacing configuration u are indexed in ascending order from 0 in the frequency domain in a common resource block-set. The common resource block with index 0 for the subcarrier-spacing configuration u includes (or collides with, matches) the point 3000. The index nuCRB of the common resource block with respect to the subcarrier-spacing configuration u satisfies the relationship of «“CRB = ceil (A:scI NRBSC). The subcarrier with ksc= 0 is a subcarrier with the same center frequency as the center frequency of the subcarrier which corresponds to the point 3000.

[0067] Physical resource blocks for a subcarrier-spacing configuration u are indexed in ascending order from 0 in the frequency domain in a BWP, The index nuPRB of the physical resource block with respect to the subcarrier-spacing configuration u satisfies the relationship of «" CRB - «UPRB + Nstart’wBWP, / . The Nstart’" BWP, I indicates the reference point of BWP with index i.

[0068] A BWP is defined as a subset of common resource blocks included in the resource grid. The BWP includes Nslze’ " BWP common resource blocks starting from the reference points Nstart,uBWP,i. A BWP for the downlink component carrier is also referred to as a downlink BWP. A BWP for the uplink component carrier is also referred to as an uplink BWP. A BWP for the sidelink is also referred to as a sidelink BWP.

[0069] An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. For example, the channel may correspond to a physical channel. For example, the symbols may correspond to OFDM symbols. For example, the symbols may correspond to resource block units. For example, the symbols may correspond to resource elements.

[0070] Two antenna ports are said to be QCL (Quasi Co-Located) if the large-scale properties of the channel over which a symbol on one antenna port is conveyed can be inferred from the channel over which a symbol on the other antenna port is conveyed. The large-scale properties include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters.

[0071] Carrier aggregation may be communication using a plurality of aggregated serving cells. Carrier aggregation may be communication using a plurality of aggregated component carriers. Carrier aggregation may be communication using a plurality ofaggregated downlink component carriers. Carrier aggregation may be communication using a plurality of aggregated uplink component carriers.

[0072] Figure 5 is a schematic block diagram showing a configuration example of the BS 3. As shown in Figure 5, the BS 3 includes at least a part or all of the wireless transmission / reception unit (physical layer processing unit) 30 and the higher-layer processing unit 34. The wireless transmission / reception unit 30 includes at least a part or all of the antenna unit 31, the RF unit 32 (Radio Frequency unit 32), and the baseband unit 33. The higher-layer processing unit 34 includes at least a part or all of the medium access control layer processing unit 35 and the radio resource control (RRC) layer processing unit 36.

[0073] The wireless transmission / reception unit 30 includes at least a part of or all of a wireless transmission unit 30a and a wireless reception unit 30b. The configuration of the baseband unit 33 included in the wireless transmission unit 30a and the configuration of the baseband unit 33 included in the wireless reception unit 30b may be the same or different. The configuration of the RF unit 32 included in the wireless transmission unit 30a and the configuration of the RF unit 32 included in the wireless reception unit 30b may be the same or different. The configuration of the antenna unit 31 included in the wireless transmission unit 30a and the configuration of the antenna unit 31 included in the wireless reception unit 30b may be the same or different.

[0074] The higher-layer processing unit 34 provides downlink data (a transport block) to the wireless transmission / reception unit 30 (or the wireless transmission unit 30a). The higher-layer processing unit 34 performs processing of a medium access control (MAC) layer, a packet data convergence protocol layer (PDCP layer), a radio link control layer (RLC layer) and / or an RRC layer.

[0075] The medium access control layer processing unit 35 included in the higher-layer processing unit 34 performs processing of the MAC layer.

[0076] The radio resource control layer processing unit 36 included in the higher-layer processing unit 34 performs the process of the RRC layer. The radio resource control layer processing unit 36 manages various configuration information I parameters (RRC parameters) of the terminal device 1. The radio resource control layer processing unit 36 configures an RRC parameter based on the RRC message received from the terminal device 1.

[0077] The wireless transmission / reception unit 30 (or the wireless transmission unit 30a) performs processing such as encoding and modulation. The wireless transmission / reception unit 30 (or the wireless transmission unit 30a) generates a physical signal by encoding and modulating the downlink data. The wireless transmission / reception unit 30 (or the wireless transmission unit 30a) converts OFDM symbols in the physical signal to a baseband signal by conversion to a time-continuous signal. The wireless transmission / reception unit 30 (or the wireless transmission unit 30a) transmits the baseband signal (or the physical signal) to the terminal device 1 via radio frequency. The wireless transmission / reception unit 30 (or the wireless transmission unit 30a) may arrange the baseband signal (or the physical signal) on a component carrier and transmit the baseband signal (or the physical signal) to the terminal device 1.

[0078] The wireless transmission / reception unit 30 (or the wireless reception unit 30b) performs processing such as demodulation and decoding. The wireless transmission / reception unit 30 (or the wireless reception unit 30b) separates, demodulates and decodes the received physical signal, and provides the decoded information to the higher-layer processing unit 34. The wireless transmission / reception unit 30 (or the wireless receptionunit 30b) may perform the channel access procedure prior to the transmission of the physical signal.

[0079] The wireless transmission / reception unit 30 may have a function to transmit one or more synchronization signal and physical broadcasting channel blocks (SSBs) to one or more terminal device 1. The wireless transmission / reception unit 30 may have a function to transmit a master information block (MIB) on physical broadcast channel (PBCH). The wireless transmission / reception unit 30 may have a function to transmit first information configuring first set of random access occasions (ROs), and second information configuring a second set of ROs. The wireless transmission / reception unit 30 may have a function to transmit third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs. The wireless transmission / reception unit 30 may have a function to transmit a PDSCH on physical resource block(s). The wireless transmission / reception unit 30 may have a function to monitor, in case that the first set of ROs is deactivated, a random access preamble on the second set of ROs, and to monitor, in case that the first set of ROs is activated, a random access preamble on the first set of ROs included in the time subset per the time periodicity and on the second set of ROs.

[0080] The RF unit 32 demodulates the physical signal received via the antenna unit 31 into a baseband signal (down convert), and / or removes extra frequency components. The RF unit 32 provides the processed analog signal to the baseband unit 33.

[0081] The baseband unit 33 converts an analog signal (signals on radio frequency) input from the RF unit 32 into a digital signal (a baseband signal). The baseband unit 33 separates a portion which corresponds to CP (Cyclic Prefix) from the digital signal. The baseband unit 33 performs Fast Fourier Transformation (FFT) on the digital signal fromwhich the CP has been removed. The baseband unit 33 provides the physical signal in the frequency domain.

[0082] The baseband unit 33 performs Inverse Fast Fourier Transformation (IFFT) on downlink data to generate an OFDM symbol, adds a CP to the generated OFDM symbol, generates a digital signal (baseband signal), and convert the digital signal into an analog signal. The baseband unit 33 provides the analog signal to the RF unit 32.

[0083] The RF unit 32 removes extra frequency components from the analog signal (signals on radio frequency) input from the baseband unit 33, up-converts the analog signal to a radio frequency, and transmits it via the antenna unit 31. The RF unit 32 may have a function of controlling transmission power. The RF unit 32 is also referred to as a transmission power control unit.

[0084] At least one or more serving cells (or one or more component carriers, one or more downlink component carriers, one or more uplink component carriers) may be configured for the terminal device 1.

[0085] Each of the serving cells set for the terminal device 1 may be any of PCell (Primary cell), PSCell (Primary SCG cell), and SCell (Secondary Cell).

[0086] A PCell is a serving cell included in an MCG (Master Cell Group). A PCell is a cell (implemented cell) which performs an initial connection establishment procedure or a connection re-establishment procedure by the terminal device 1.

[0087] A PSCell is a serving cell included in a SCG (Secondary Cell Group). A PSCell is a serving cell in which random-access is performed by the terminal device 1 in a reconfiguration procedure with synchronization (Reconfiguration with synchronization).

[0088] A SCell may be included in either an MCG or a SCG.

[0089] The serving cell group (cell group) is a designation including at least MCG and SCG. The serving cell group may include one or more serving cells (or one or more component carriers). One or more serving cells (or one or more component carriers) included in the serving cell group may be operated by carrier aggregation.

[0090] One or more downlink BWPs may be configured for each serving cell (or each downlink component carrier). One or more uplink BWPs may be configured for each serving cell (or each uplink component carrier).

[0091] Among the one or more downlink BWPs set for the serving cell (or the downlink component carrier), one downlink BWP may be set as an active downlink BWP (or one downlink BWP may be activated). Among the one or more uplink BWPs set for the serving cell (or the uplink component carrier), one uplink BWP may be set as an active uplink BWP (or one uplink BWP may be activated).

[0092] A PDSCH, a PDCCH, a CSI-RS and other physical downlink channels / signals may be received in the active downlink BWP. The terminal device 1 may receive the PDSCH, the PDCCH, and the CSI-RS in the active downlink BWP. Additionally, in some case, the terminal device 1 may receive the CSI-RS or other physical downlink channels / signals (e.g., Positioning RS (PRS)) in the downlink BWP that is not active or in the cell that is not a serving cell. A PUCCH, a PUSCH, an SRS and other physical uplink channels / signals may be sent on the active uplink BWP. The terminal device 1 may transmit the PUCCH, the PUSCH, the SRS and other physical uplink channels / signals in the active uplink BWP. Additionally, in some case, the terminal device 1 may receive the SRS or other physical uplink channels / signals (e.g., SRS for Positioning) in the uplink BWP that is not active or in the cell that is not a serving cell. The active downlink BWP and the active uplink BWP are also referred to as active BWP.

[0093] Downlink BWP switching deactivates an active downlink BWP and activates one of inactive downlink BWPs which are other than the active downlink BWP. The downlink BWP switching may be controlled by a BWP field included in a downlink control information. The downlink BWP switching may be controlled based on higher-layer parameters.

[0094] Uplink BWP switching is used to deactivate an active uplink BWP and activate any inactive uplink BWP which is other than the active uplink BWP. Uplink BWP switching may be controlled by a BWP field included in a downlink control information. The uplink BWP switching may be controlled based on higher-layer parameters.

[0095] Among the one or more downlink BWPs set for the serving cell, two or more downlink BWPs may not be set as active downlink BWPs. For the serving cell, one downlink BWP may be active at a certain time.

[0096] Among the one or more uplink BWPs set for the serving cell, two or more uplink BWPs may not be set as active uplink BWPs. For the serving cell, one uplink BWP may be active at a certain time.

[0097] The aforementioned procedures for Uplink BWP may be applicable to Sidelink BWP.

[0098] Figure 6 is a schematic block diagram showing a configuration example of the terminal device 1. As shown in Figure 6, the terminal device 1 includes at least a part or all of the wireless transmission / reception unit (physical layer processing unit) 10 and the higher-layer processing unit 14. The wireless transmission / reception unit 10 includes at least a part or all of the antenna unit 11, the RF unit 12, and the baseband unit 13. The higher- layer processing unit 14 includes at least a part or all of the medium access control layer processing unit 15 and the radio resource control layer processing unit 16.

[0099] The wireless transmission I reception unit 10 includes at least a part of or all of a wireless transmission unit 10a and a wireless reception unit 10b. The configuration of the baseband unit 13 included in the wireless transmission unit 10a and the configuration of the baseband unit 13 included in the wireless reception unit 10b may be the same or different. The configuration of the RF unit 12 included in the wireless transmission unit 10a and the RF unit 12 included in the wireless reception unit 10b may be the same or different. The configuration of the antenna unit 11 included in the wireless transmission unit 10a and the configuration of the antenna unit 11 included in the wireless reception unit 10b may be the same or different.

[0100] The higher-layer processing unit 14 provides uplink or sidelink data (a transport block) to the wireless transmission / reception unit 10 (or the wireless transmission unit 10a). The higher-layer processing unit 14 performs processing of a MAC layer, a packet data integration protocol layer, a radio link control layer, and / or an RRC layer. The higher-layer processing unit 14 may also performs processing of a MAC layer, a packet data integration protocol layer, a radio link control layer, and / or an RRC layer for PC5.

[0101] The medium access control layer processing unit 15 included in the higher-layer processing unit 14 performs processing of the MAC layer.

[0102] The radio resource control layer processing unit 16 included in the higher- layer processing unit 14 performs the process of the RRC layer and / or the PC5 RRC (PC5-RRC) process. The radio resource control layer processing unit 16 manages various configuration information I parameters (RRC parameters and / or PC5 RRC (PC5-RRC) parameters) of the terminal device 1. The radio resource control layer processing unit 16 configures RRC parameters based on the RRC message received from the BS 3 and / orPC5 RRC parameters based on the PC5 RRC (PC5-RRC) message received from another terminal device 1.

[0103] The wireless transmission / reception unit 10 (or the wireless transmission unit 10a) performs processing such as encoding and modulation. The wireless transmission / reception unit 10 (or the wireless transmission unit 10a) generates a physical signal by encoding and modulating the uplink data and / or sidelink data. The wireless transmission / reception unit 10 (or the wireless transmission unit 10a) converts OFDM symbols in the physical signal to a baseband signal by conversion to a time-continuous signal. The wireless transmission / reception unit 10 (or the wireless transmission unit 10a) transmits the baseband signal (or the physical signal) to the BS 3 or to another terminal device 1 via radio frequency. The wireless transmission / reception unit 10 (or the wireless transmission unit 10a) may arrange the baseband signal (or the physical signal) on a BWP (active uplink BWP) and transmit the baseband signal (or the physical signal) to the BS 3.

[0104] The wireless transmission / reception unit 10 (or the wireless reception unit 10b) performs processing such as demodulation and decoding. The wireless transmission / reception unit 10 (or the wireless reception unit 10b) may receive a physical signal in a BWP (active downlink BWP) of a serving cell and / or in a Sidelink BWP. The wireless transmission / reception unit 10 (or the wireless reception unit 10b) separates, demodulates and decodes the received physical signal, and provides the decoded information to the higher-layer processing unit 14. The wireless transmission / reception unit 10 (or the wireless reception unit 10b) may perform the channel access procedure prior to the transmission of the physical signal.

[0105] The wireless transmission / reception unit 10 may have a function to receive, from a BS 3, one or more synchronization signal and physical broadcasting channel blocks (SSBs). The wireless transmission I reception unit 10 may have a function to receive a master information block (MIB). The wireless transmission / reception unit 10 may have a function to receive first information configuring first set of random access occasions (ROs), and second information configuring a second set of ROs. The wireless transmission I reception unit 10 may have a function to receive a PDSCH on physical resource block(s). The wireless transmission / reception unit 10 may have a function to receive third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs. The wireless transmission / reception unit 10 may have a function to transmit a random access preamble on a random access occasion in the available ROs.

[0106] The RF unit 12 demodulates the physical signal received via the antenna unit 11 into a baseband signal (down convert), and / or removes extra frequency components. The RF unit 12 provides the processed analog signal to the baseband unit 13.

[0107] The baseband unit 13 converts an analog signal (signals on radio frequency) input from the RF unit 12 into a digital signal (a baseband signal). The baseband unit 13 separates a portion which corresponds to CP from the digital signal, performs fast Fourier transformation on the digital signal from which the CP has been removed, and provides the physical signal in the frequency domain.

[0108] The baseband unit 13 performs inverse fast Fourier transformation on uplink data to generate an OFDM symbol, adds a CP to the generated OFDM symbol, generates a digital signal (baseband signal), and convert the digital signal into an analog signal. The baseband unit 13 provides the analog signal to the RF unit 12.

[0109] The RF unit 12 removes extra frequency components from the analog signal (signals on radio frequency) input from the baseband unit 13, up-converts the analog signal to a radio frequency, and transmits it via the antenna unit 11 The RF unit 12 may have a function of controlling transmission power. The RF unit 12 is also referred to as a transmission power control unit.

[0110] The higher-layer processing unit 14 may have a function to select an SSB from the one or more SSBs based on one or more reference signal received power (RSRP) thresholds. The higher-layer processing unit 14 may have a function to determine, in case that the first set of ROs is deactivated, available ROs from the second set of ROs, and to determine, in case that the first set of ROs is activated, the available ROs from the first set of ROs included in the time subset per the time periodicity and the second set of ROs.

[0111] Hereinafter, physical signals (signals) will be described.

[0112] Physical signal is a generic term for downlink physical channels, downlink physical signals, uplink physical channels, uplink physical signals, sidelink physical channels, and sidelink physical signals. The physical channel is a generic term for downlink physical channels, uplink physical channels and sidelink physical channels.

[0113] An uplink physical channel may correspond to a set of resource elements that carry information originating from the higher-layer and / or uplink control information. The uplink physical channel may be a physical channel used in an uplink component carrier. The uplink physical channel may be transmitted by the terminal device 1. The uplink physical channel may be received by the BS 3. In the wireless communication system according to one aspect of the present embodiment, at least part or all of PUCCH (Physical Uplink Control CHannel), PUSCH (Physical Uplink Shared CHannel), and PRACH (Physical Random Access CHannel) may be used.

[0114] A PUCCH may be used to transmit uplink control information (UCI). The PUCCH may be sent to deliver (transmission, convey) uplink control information. The uplink control information may be mapped to (or arranged in) the PUCCH. The terminal device 1 may transmit PUCCH in which uplink control information is arranged. The BS 3 may receive the PUCCH in which the uplink control information is arranged.

[0115] Uplink control information (uplink control information bit, uplink control information sequence, uplink control information type) includes at least part or all of channel state information (CSI), scheduling request (SR), and HARQ-ACK (Hybrid Automatic Repeat request ACKnowledgement).

[0116] Channel state information is conveyed by using channel state information bits or a channel state information sequence. Scheduling request is also referred to as a scheduling request bit or a scheduling request sequence. HARQ-ACK information is also referred to as a HARQ-ACK information bit or a HARQ-ACK information sequence.

[0117] HARQ-ACK information may include HARQ-ACK status which corresponds to a transport block (TB: Transport block, MAC PDU: Medium Access Control Protocol Data Unit, DL-SCH: Downlink-Shared Channel, UL-SCH: Uplink-Shared Channel, PDSCH: Physical Downlink Shared CHannel, PUSCH: Physical Uplink Shared CHannel). The HARQ-ACK status may indicate ACK (acknowledgement) or NACK (negative-acknowledgement) corresponding to the transport block. The ACK may indicate that the transport block has been successfully decoded. The NACK may indicate that the transport block has not been successfully decoded. The HARQ-ACK information may include a HARQ-ACK codebook that includes one or more HARQ-ACK status (or HARQ-ACK bits).

[0118] For example, the correspondence between the HARQ-ACK information and the transport block may mean that the HARQ-ACK information and the PDSCH used for transmission of the transport block correspond.

[0119] HARQ-ACK status may indicate ACK or NACK which correspond to one CBG (Code Block Group) included in the transport block.

[0120] The scheduling request may at least be used to request PUSCH (or UL-SCH) resources for new transmission. The scheduling request may be used to indicate either a positive SR or a negative SR. The fact that the scheduling request indicates a positive SR is also referred to as "a positive SR is sent". The positive SR may indicate that the PUSCH (or UL-SCH) resource for initial transmission is requested by the terminal device 1. A positive SR may indicate that a higher-layer is to trigger a scheduling request. The positive SR may be sent when the higher-layer instructs to send a scheduling request. The fact that the scheduling request bit indicates a negative SR is also referred to as "a negative SR is sent". A negative SR may indicate that the PU SCH (or UL-SCH) resource for initial transmission is not requested by the terminal device 1. A negative SR may indicate that the higher-layer does not trigger a scheduling request. A negative SR may be sent if the higher-layer is not instructed to send a scheduling request.

[0121] The channel state information may include at least part or all of a channel quality indicator (CQI), a precoder matrix indicator (PMI), and a rank indicator (RI). CQI is an indicator related to channel quality (e.g., propagation quality) or physical channel quality, and PMI is an indicator related to a precoder. RI is an indicator related to transmission rank (or the number of transmission layers).

[0122] Channel state information may be provided at least based on receiving one or more physical signals (e.g., one or more CSI-RSs) used at least for channel measurement.The channel state information may be selected by the terminal device 1 at least based on receiving one or more physical signals used for channel measurement. Channel measurements may include interference measurements.

[0123] A PUCCH may correspond to a PUCCH format. A PUCCH may be a set of resource elements used to convey a PUCCH format. A PUCCH may include a PUCCH format. A PUCCH format may include UCI.

[0124] A PUSCH may be used to transmit uplink data (a transport block) and / or uplink control information. A PUSCH may be used to transmit uplink data (a transport block) corresponding to a UL-SCH and / or uplink control information. A PUSCH may be used to convey uplink data (a transport block) and / or uplink control information. A PUSCH may be used to convey uplink data (a transport block) corresponding to a UL-SCH and / or uplink control information. Uplink data (a transport block) may be arranged in a PUSCH. Uplink data (a transport block) corresponding to UL-SCH may be arranged in a PUSCH. Uplink control information may be arranged to a PUSCH. The terminal device 1 may transmit a PUSCH in which uplink data (a transport block) and / or uplink control information is arranged. The BS 3 may receive a PUSCH in which uplink data (a transport block) and / or uplink control information is arranged.

[0125] A PRACH may be used to transmit a random-access preamble. The PRACH may be used to convey a random-access preamble. The sequence xu, v (n) of the PRACH is defined by xu,v(n) = xu(mod (n + Cv, LRA)). The xumay be a ZC sequence (Zadoff-Chu sequence). The xumay be defined by xu= exp (-jpui (i + 1) / LRA). The j is an imaginary unit. The p is the circle ratio. The Cv corresponds to cyclic shift of the PRACH. LRA corresponds to the length of the PRACH. The LRA may be 839 or 139 or another value. The i is an integer in the range of 0 to LRA-1. The u is a sequence index for thePRACH. A transmission of PRACH means a transmission of random-access preamble on PRACH. The terminal device 1 may transmit the PRACH. The BS 3 may receive the PRACH. Single PRACH transmission is a transmission of a random access preamble on a PRACH occasion. Multiple PRACH transmissions (can be called as PRACH repetition, preamble repetitions and / or Msgl repetition) is multiple transmissions of a random access preamble on multiple PRACH occasions within a PRACH attempt.

[0126] For a given PRACH occasion, 64 random-access preambles are defined. The random-access preamble is specified (determined, given) at least based on the cyclic shift Cvof the PRACH and the sequence index u for the PRACH.

[0127] An uplink physical signal may correspond to a set of resource elements. The uplink physical signal may not carry information generated in the higher-layer. The uplink physical signal may be a physical signal used in the uplink component carrier. The terminal device 1 may transmit an uplink physical signal. The BS 3 may receive the uplink physical signal. In the radio communication system according to one aspect of the present embodiment, at least a part or all of UL DMRS (UpLink Demodulation Reference Signal), SRS (Sounding Reference Signal), UL PTRS (UpLink Phase Tracking Reference Signal) may be used.

[0128] UL DMRS is a generic name of a DMRS for a PUSCH and a DMRS for a PUCCH.

[0129] A set of antenna ports of a DMRS for a PUSCH (a DMRS associated with a PUSCH, a DMRS included in a PUSCH, a DMRS which corresponds to a PUSCH) may be given based on a set of antenna ports for the PUSCH. That is, the set of DMRS antenna ports for the PUSCH may be the same as the set of antenna ports for the PUSCH.

[0130] Transmission of a PUSCH and transmission of a DMRS for the PUSCH may be indicated (or scheduled) by one DCI format. The PUSCH and the DMRS for the PUSCH may be collectively referred to as a PUSCH. Transmission of the PUSCH may be transmission of the PUSCH and the DMRS for the PUSCH.

[0131] A PUSCH may be estimated from a DMRS for the PUSCH. That is, propagation path of the PUSCH may be estimated from the DMRS for the PUSCH.

[0132] A set of antenna ports of a DMRS for a PUCCH (a DMRS associated with a PUCCH, a DMRS included in a PUCCH, a DMRS which corresponds to a PUCCH) may be identical to a set of antenna ports for the PUCCH.

[0133] Transmission of a PUCCH and transmission of a DMRS for the PUCCH may be indicated (or triggered) by one DCI format. The arrangement of the PUCCH in resource elements (resource element mapping) and / or the arrangement of the DMRS in resource elements for the PUCCH may be provided at least by one PUCCH format. The PUCCH and the DMRS for the PUCCH may be collectively referred to as PUCCH. Transmission of the PUCCH may be transmission of the PUCCH and the DMRS for the PUCCH.

[0134] A PUCCH may be estimated from a DMRS for the PUCCH. That is, propagation path of the PUCCH may be estimated from the DMRS for the PUCCH.

[0135] A downlink physical channel may correspond to a set of resource elements that carry information originating from the higher-layer and / or downlink control information. The downlink physical channel may be a physical channel used in the downlink component carrier. The BS 3 may transmit the downlink physical channel. The terminal device 1 may receive the downlink physical channel. In the wireless communication system according to one aspect of the present embodiment, at least a partor all of PBCH (Physical Broadcast Channel), PDCCH (Physical Downlink Control Channel), and PDSCH (Physical Downlink Shared Channel) may be used.

[0136] The downlink physical channels including PBCH and PDSCH may be used to provide system information (SI) to one or more terminal devices 1.

[0137] SI is divided into the MIB (Master Information Block) and a number of SIBs (System Information Block(s)).

[0138] The MIB is always transmitted on the BCH with a periodicity of 80 ms and repetitions made within 80 ms and it includes parameters that are needed to acquire SIB1 from the cell. The first transmission of the MIB is scheduled in subframes and repetitions are scheduled according to the period of SSB.

[0139] The SIB1 may be transmitted on the DL-SCH with a periodicity of 160 ms and variable transmission repetition periodicity within 160 ms. The default transmission repetition periodicity of SIB1 is 20 ms but the actual transmission repetition periodicity may be up to network implementation. SIB1 repetition transmission period may be 20 ms. SIB1 transmission repetition period may be the same as the SSB period. SIB1 includes information regarding the availability and scheduling (e.g. mapping of SIBs to SI message, periodicity, Si-window size) of other SIBs with an indication whether one or more SIBs are only provided on-demand and, in that case, the configuration needed by the terminal device 1 to perform the SI request. SIB1 may be cell-specific SIB.

[0140] SIB1 may be provided on-demand. The terminal device 1 may perform SIB1 request if the SIB1 is not provided for corresponding SS / PBCH block (SSB). A channel / signal used to perform SIB1 request may be called as uplink wakeup signal (UL- WUS). The SIB1 request may be performed by transmitting a random access preambleon PRACH using a certain configuration (e.g. use of the dedicated random access preamble for SIB1 request and / or a dedicated random access resource for SIB1 request).

[0141] SIBs other than SIB1 and posSIBs are carried in Systeminformation (SI) messages, which are transmitted on the DL-SCH. Only SIBs or posSIBs having the same periodicity can be mapped to the same SI message. SIBs and posSIBs are mapped to different SI messages, i.e. an SI message contains either only SIBs or only posSIBs. Each SI message is transmitted within periodically occurring time domain windows (referred to as Si-windows with same length for all SI messages). Each SI message is associated with an Si-window and the Si-windows of different SI messages do not overlap. That is, within one Si-window only the corresponding SI message is transmitted. An SI message may be repeated with the same content a number of times within the Si-window. Any SIB or posSIB except SIB1 can be configured to be cell specific or area specific, using an indication in SIB1. The cell specific SIB is applicable only within a cell that provides the SIB while the area specific SIB is applicable within an area referred to as SI area, which consists of one or several cells and is identified by systemlnformationArealD.

[0142] The mapping of SIBs to SI messages is configured in higher layer parameter schedulinglnfoList and higher layer parameter schedulingInfoList2, while the mapping of posSIBs to SI messages is configured in higher layer parameter posSchedulinglnfoList and higher layer parameter schedulingInfoList2. Each SIB and each posSIB is mapped to a single SI message.

[0143] For a terminal device 1 in RRC CONNECTED state, the network can provide system information through dedicated signalling for the terminal device 1 using the RRCReconfiguration message.

[0144] For PSCell and SCells, the network provides the required SI by dedicated signalling, i.e. within an RRCReconfiguration message. Nevertheless, the terminal device 1 shall acquire MIB of the PSCell to get SFN timing of the SCG (which may be different from MCG). Upon change of relevant SI for SCell, the network releases and adds the concerned SCell. For PSCell, the required SI can only be changed with Reconfiguration with Sync.

[0145] The PBCH may be used to transmit a MIB and / or physical layer control information. The physical layer control information is a kind of downlink control information. The PBCH may be sent to deliver the MIB and / or the physical layer control information. A BCH may be mapped (or corresponding) to the PBCH. The terminal device 1 may receive the PBCH. The BS 3 may transmit the PBCH. The physical layer control information is also referred to as a PBCH payload and a PBCH payload related to timing. The MIB may include one or more higher-layer parameters.

[0146] Figure 7 is an example showing the higher layer parameters included in MIB which is a higher layer parameter for MIB and the higher layer parameters included in PDCCH-ConfigSIBl which is an IE for pdcch-ConfigSIBl included in MIB.

[0147] The higher layer parameter MIB includes parameter systemFrameNumber, parameter subCarrierSpacingCommon, parameter ssb-Subcarrier Offset, parameter dmrs- TypeA-Position, parameter pdcch-ConfigSIBl, parameter cellBarred, intraFreqReselection and spare bit.

[0148] systemFrameNumber indicates the 6 most significant bits (MSB) of the 10-bit System Frame Number (SFN). The 4 LSB of the SFN are conveyed in the PBCH transport block as part of channel coding (i.e. outside the MIB encoding).

[0149] subCarrierSpacingCommon indicates subcarrier spacing for SIB1, Msg.2 / 4 and MsgB for initial access, paging and broadcast Si-messages. If the terminal device 1 acquires this MIB on an FR1 carrier frequency, the value scsl5or60 corresponds to 15 kHz and the value scs30or!20 corresponds to 30 kHz. If the terminal device 1 acquires this MIB on an FR2 carrier frequency, the value scs!5or60 corresponds to 60 kHz and the value scs30or!20 corresponds to 120 kHz. For operation with shared spectrum channel access in FR1 and for operation in FR2-2, the subcarrier spacing for SIB1, Msg.2 / 4 and MsgB for initial access, paging and broadcast Si-messages is same as that for the corresponding SSB. For operation with shared spectrum channel access, this field instead is used for deriving the QCL relation between SS / PBCH blocks.

[0150] ssb-SubcarrierOffset corresponds to £_SSB, which is the frequency domain offset between SSB and the overall resource block grid in number of subcarriers. The k_SSB is determined based on the ssb-SubcarrierOffset in the acquired MIB. For operation with shared spectrum channel access in FR1, this field corresponds toSSB, and &_SSB is obtained fromSSB. The 4 least significant bits of kSSBare given by the ssb-SubcarrierOffset and the most significant bit of kSSBis given by the PBCH payload. If k̄SSB≥ 24, k_SSB = k̄SSB; otherwise, k_SSB = 2[k̄SSB / 2]. The LSB of this field is used also for deriving the QCL relation between SS / PBCH blocks. This field may indicate that this cell does not provide SIB1 and that there is hence no CORESET 0 configured in MIB. In this case, the field pdcch-ConfigSIBl may indicate the frequency positions where the UE may (not) find a SS / PBCH with a control resource set and search space for SIB1 or configuration of uplink wakeup signal to request the base station 3 to transmit SS / PBCH block with a control resource set and search space for SIB 1 (or SS / PBCH block which is associated with SIB1).

[0151] dmrs-TypeA-Position indicates position of (first) DM-RS for downlink and uplink.

[0152] pdcch-ConfigSIB1 determines a common ControlResourceSet (CORESET), a common search space and necessary PDCCH parameters. If the field ssb-SubcarrierOffset indicates that SIB1 is absent, the field pdcch-ConfigSIB1 indicates the frequency positions where the UE may find SS / PBCH block with SIB1, the frequency range where the network does not provide SS / PBCH block with SIB1 or the configuration of SIB1 request signal (can be referred as uplink wakeup signal: UL-WUS).

[0153] cellBarred indicates if the cell is barred. Value barred means that the cell is barred.

[0154] intraFreqReselection controls cell selection / reselection to intra-frequency cells when the highest ranked cell is barred, or treated as barred by the UE.

[0155] The IE PDCCH-ConfigSIBl is used to configure CORESET#0 and search space#0. The PDCCH-ConfigSIBl includes parameter controlResourceSetZero and parameter searchSpaceZero.

[0156] controlResourceSetZero may be used to determine a common ControlResourceSet (CORESET) with ID #0 (can be referred as CORESET#0). The CORESET#0 is a control resource set for at least SIB1 scheduling, can be configured either via MIB or via dedicated RRC signalling. The CORESET 0 is a special type of CORESET which carries PDCCH / DCI for SIB1.

[0157] searchSpaceZero may be used to determines a common search space with ID #0.

[0158] Physical layer control information includes 8 bits. The physical layer control information may include at least part or all of 0A to 0D. The 0A is radio frame information.The OB is half radio frame information (half system frame information). The OC is SS / PBCH block index information. The OD is subcarrier offset information.

[0159] The radio frame information is used to indicate a radio frame in which the PBCH is transmitted (a radio frame including a slot in which the PBCH is transmitted). The radio frame information is represented by 4 bits. The radio frame information may be represented by 4 bits of a radio frame indicator. The radio frame indicator may include 10 bits. For example, the radio frame indicator may at least be used to identify a radio frame from index 0 to index 1023.

[0160] The half radio frame information is used to indicate whether the PBCH is transmitted in first five subframes or in second five subframes among radio frames in which the PBCH is transmitted. Here, the half radio frame may be configured to include five subframes. The half radio frame may be configured by five subframes of the first half of ten subframes included in the radio frame. The half radio frame may be configured by five subframes in the second half of ten subframes included in the radio frame.

[0161] The SS / PBCH block index information is used to indicate an SS / PBCH block index. The SS / PBCH block index information may be represented by 3 bits. The SS / PBCH block index information may consist of 3 bits of an SS / PBCH block index indicator. The SS / PBCH block index indicator may include 6 bits. The SS / PBCH block index indicator may at least be used to identify an SS / PBCH block from index 0 to index 63 (or from index 0 to index 3, from index 0 to index 7, from index 0 to index 9, from index 0 to index 19, etc.).

[0162] The subcarrier offset information is used to indicate subcarrier offset. The subcarrier offset information may be used to indicate the difference between the firstsubcarrier in which the PBCH is arranged and the first subcarrier in which the control resource set with index 0 is arranged.

[0163] A PDCCH may be used to transmit downlink control information (DCI). A PDCCH may be transmitted to deliver downlink control information. Downlink control information may be mapped to a PDCCH. The terminal device 1 may receive a PDCCH in which downlink control information is arranged. The BS 3 may transmit the PDCCH in which the downlink control information is arranged.

[0164] Downlink control information may correspond to a DCI format. Downlink control information may be included in a DCI format. Downlink control information may be arranged in each field of a DCI format.

[0165] DCI format is a generic name for DCI format 0_0, DCI format 0_1, DCI format 1_0, and DCI format 1_1. Uplink DCI format is a generic name of the DCI format 0_0 and the DCI format 0_1. Downlink DCI format is a generic name of the DCI format 1_0 and the DCI format 1_1.

[0166] Radio Network Temporary Identifier (RNTI) is used to differentiate / identify a connected terminal device 1 (UE) in the cell, a specific radio channel, a group of terminal devices 1 in case of paging, a group of terminal devices 1 for which power control is issued by the base station 3, system information transmitted for all the terminal devices 1 by base station 3 (gNB). RNTI is a 16-bit identifier and its value depends on type of RNTI including SI-RNTI, P-RNTI, RA-RNTI, TC-RNTI, C-RNTI, MCS-C-RNTI, CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI, INT-RNTI, SFI-RNTI and SP-CSI-RNTI.

[0167] A PDSCH may be used to transmit one or more transport blocks. A PDSCH may be used to transmit one or more transport blocks which corresponds to a DL-SCH.A PDSCH may be used to convey one or more transport blocks. A PDSCH may be used to convey one or more transport blocks which corresponds to a DL-SCH. One or more transport blocks may be arranged in a PDSCH. One or more transport blocks which corresponds to a DL-SCH may be arranged in a PDSCH. The BS 3 may transmit a PDSCH. The terminal device 1 may receive the PDSCH.

[0168] Downlink physical signals may correspond to a set of resource elements. The downlink physical signals may not carry the information generated in the higher-layer. The downlink physical signals may be physical signals used in the downlink component carrier. A downlink physical signal may be transmitted by the BS 3. The downlink physical signal may be transmitted by the terminal device 1. In the wireless communication system according to one aspect of the present embodiment, at least a part or all of an SS (Synchronization signal), DL DMRS (DownLink DeModulation Reference Signal), CSI-RS (Channel State Information-Reference Signal), and DL PTRS (DownLink Phase Tracking Reference Signal) may be used.

[0169] The synchronization signal may be used at least for the terminal device 1 to synchronize in the frequency domain and / or time ‘domain for downlink. The synchronization signal is a generic name of PSS (Primary Synchronization Signal) and SSS (Secondary Synchronization Signal).

[0170] Figure 8 is a diagram showing a configuration example of an SS / PBCH block. In Figure 8, the horizontal axis indicates time domain (OFDM symbol index lsym), and the vertical axis indicates frequency domain. The shaded blocks indicate a set of resource elements for a PSS. The blocks of grid lines indicate a set of resource elements for an SSS. Also, the blocks in the horizontal line indicate a set of resource elements for a PBCHand a set of resource elements for a DMRS for the PBCH (DMRS related to the PBCH, DMRS included in the PBCH, DMRS which corresponds to the PBCH).

[0171] As shown in Figure 8, the SS / PBCH block includes a PSS, an SSS, and a PBCH. The SS / PBCH block includes 4 consecutive OFDM symbols. The SS / PBCH block includes 240 subcarriers. The PSS is allocated to the 57th to 183rd subcarriers in the first OFDM symbol. The SSS is allocated to the 57th to 183rd subcarriers in the third OFDM symbol. The first to 56th subcarriers of the first OFDM symbol may be set to zero. The 184th to 240th subcarriers of the first OFDM symbol may be set to zero. The 49th to 56th subcarriers of the third OFDM symbol may be set to zero. The 184th to 192nd subcarriers of the third OFDM symbol may be set to zero. In the first to 240th subcarriers of the second OFDM symbol, the PBCH is allocated to subcarriers in which the DMRS for the PBCH is not allocated. In the first to 48th subcarriers of the third OFDM symbol, the PBCH is allocated to subcarriers in which the DMRS for the PBCH is not allocated. In the 193rd to 240th subcarriers of the third OFDM symbol, the PBCH is allocated to subcarriers in which the DMRS for the PBCH is not allocated. In the first to 240th subcarriers of the 4th OFDM symbol, the PBCH is allocated to subcarriers in which the DMRS for the PBCH is not allocated.

[0172] The antenna ports of a PSS, an SSS, a PBCH, and a DMRS for the PBCH in an SS / PBCH block may be identical.

[0173] A PBCH may be estimated from a DMRS for the PBCH. For the DM-RS for the PBCH, the channel over which a symbol for the PBCH on an antenna port is conveyed can be inferred from the channel over which another symbol for the DM-RS on the antenna port is conveyed only if the two symbols are within a SS / PBCH block transmitted within the same slot, and with the same SS / PBCH block index.

[0174] DL DMRS is a generic name of DMRS for a PBCH, DMRS for a PDSCH, and DMRS for a PDCCH.

[0175] A set of antenna ports for a DMRS for a PDSCH (a DMRS associated with a PDSCH, a DMRS included in a PDSCH, a DMRS which corresponds to a PDSCH) may be given based on the set of antenna ports for the PDSCH. The set of antenna ports for the DMRS for the PDSCH may be the same as the set of antenna ports for the PDSCH.

[0176] Transmission of a PDSCH and transmission of a DMRS for the PDSCH may be indicated (or scheduled) by one DCI format. The PDSCH and the DMRS for the PDSCH may be collectively referred to as PDSCH. Transmitting a PDSCH may be transmitting a PDSCH and a DMRS for the PDSCH.

[0177] A PDSCH may be estimated from a DMRS for the PDSCH. For a DM-RS associated with a PDSCH, the channel over which a symbol for the PDSCH on one antenna port is conveyed can be inferred from the channel over which another symbol for the DM-RS on the antenna port is conveyed only if the two symbols are within the same resource as the scheduled PDSCH, in the same slot, and in the same PRG (Precoding Resource Group).

[0178] Antenna ports for a DMRS for a PDCCH (a DMRS associated with a PDCCH, a DMRS included in a PDCCH, a DMRS which corresponds to a PDCCH) may be the same as an antenna port for the PDCCH.

[0179] A PDCCH may be estimated from a DMRS for the PDCCH. For a DM-RS associated with a PDCCH, the channel over which a symbol for the PDCCH on one antenna port is conveyed can be inferred from the channel over which another symbol for the DM-RS on the same antenna port is conveyed only if the two symbols are withinresources for which the UE may assume the same precoding being used (i.e. within resources in a REG bundle).

[0180] A BCH (Broadcast CHannel), a UL-SCH (Uplink-Shared CHannel) and a DL-SCH (Downlink-Shared CHannel) are transport channels. A channel used in the MAC layer is called a transport channel. A unit of transport channel used in the MAC layer is also called transport block (TB) or MAC PDU (Protocol Data Unit). In the MAC layer, control of HARQ (Hybrid Automatic Repeat request) is performed for each transport block. The transport block is a unit of data delivered by the MAC layer to the physical layer. In the physical layer, transport blocks are mapped to codewords and modulation processing is performed for each codeword.

[0181] One UL-SCH and one DL-SCH may be provided for each serving cell. BCH may be given to PCell. BCH may not be given to PSCell and SCell.

[0182] ABCCH (Broadcast Control CHannel), a CCCH (Common Control CHannel), and a DCCH (Dedicated Control CHannel) are logical channels. The BCCH is a channel of the RRC layer used to deliver MIB or system information. The CCCH may be used to transmit a common RRC message in a plurality of terminal devices 1. The CCCH may be used for the terminal device 1 which is not connected by RRC. The DCCH may be used at least to transmit a dedicated RRC message to the terminal device 1. The DCCH may be used for the terminal device 1 that is in RRC-connected mode.

[0183] The RRC message includes one or more RRC parameters (information elements, higher layer parameters). For example, the RRC message may include a MIB. For example, the RRC message may include system information (SIB: System Information Block, MIB). SIB is a generic name for various type of SIBs (e.g., SIB1, SIB2). For example, the RRC message may include a message which corresponds to aCCCH. For example, the RRC message may include a message which corresponds to a DCCH. RRC message is a general term for common RRC message and dedicated RRC message,

[0184] The BCCH in the logical channel may be mapped to the BCH or the DL-SCH in the transport channel. The CCCH in the logical channel may be mapped to the DL-SCH or the UL-SCH in the transport channel. The DCCH in the logical channel may be mapped to the DL-SCH or the UL-SCH in the transport channel.

[0185] The UL-SCH in the transport channel may be mapped to a PUSCH in the physical channel. The DL-SCH in the transport channel may be mapped to a PDSCH in the physical channel. The BCH in the transport channel may be mapped to a PBCH in the physical channel.

[0186] A higher-layer parameter is a parameter included in an RRC message or a MAC CE (Medium Access Control - Control Element). The higher-layer parameter is a generic name of information included in a MIB, system information, a message which corresponds to CCCH, a message which corresponds to DCCH, and a MAC CE. A higher-layer parameter may be referred to as an RRC parameter or an RRC configuration if the higher-layer parameter is the parameter included in the RRC message.

[0187] A higher-layer parameter may be a cell-specific parameter or a UE-specific parameter. A cell-specific parameter is a parameter including a common configuration in a cell. A UE-specific parameter is a parameter including a configuration that may be configured differently for each UE.

[0188] The BS 3 may indicate change of cell-specific parameters by reconfiguration with random-access. The UE may change cell-specific parameters before triggering random-access. The BS 3 may indicate change of UE-specific parameters byreconfiguration with or without random-access. The UE may change UE-specific parameters before or after random-access.

[0189] The procedure performed by the terminal device 1 includes at least a part or all of the following 5A to 5C. The 5A is cell search. The 5B is random-access. The 5C is data communication.

[0190] The cell search is a procedure used by the terminal device 1 to synchronize with a cell in the time domain and / or the frequency domain and to detect a physical cell identity (PCI). The terminal device 1 may detect the physical cell ID by performing synchronization of time domain and / or frequency domain with a cell by the cell search. The cell search is based on the primary synchronization signal (PSS), secondary synchronization signal (SSS), and PBCH DMRS, located on the synchronization raster.

[0191] A sequence of a PSS is given based at least on a physical cell ID (PCI). A sequence of an SSS is given based at least on the physical cell ID (PCI). PSS has 3 values 0,1 and 2 and created using m-sequence. SSS has 336 values 0 to 335 and generated using product of 2 m-sequences. PCI values will vary from 0 to 1007.

[0192] The PCI is used to distinguish cells on the radio. The PCIs of SS / PBCH blocks transmitted in different frequency locations do not have to be unique, i.e. different SS / PBCH blocks in the frequency domain can have different PCIs. However, when an SS / PBCH block is associated with an RMSI, the SS / PBCH block is referred to as a Cell- Defining SSB (CD-SSB). A PCell is always associated to a CD-SSB located on the synchronization raster.

[0193] When an SS / PBCH block is not associated with an RMSI, the SS / PBCH block is referred to as a non-Cell Defining SSB (NCD-SSB), which can be used to perform radio link monitoring (RLM), beam failure detection (BFD), and radio resourcemanagement (RRM) measurements and measurements for RA resource selection inside the active DL BWP when the active BWP does not contain the CD-SSB. The terminal device 1 may be configured with multiple SSBs provided that each BWP is configured with at most one SSB (CD-SSB or NCD-SSB).

[0194] An SS / PBCH block candidate indicates a resource for which transmission of the SS / PBCH block may exist. An SS / PBCH block may be transmitted at a resource indicated as the SS / PBCH block candidate. The BS 3 may transmit an SS / PBCH block at an SS / PBCH block candidate. The terminal device 1 may receive (detect) the SS / PBCH block at the SS / PBCH block candidate.

[0195] A set of SS / PBCH block candidates in a half radio frame is also referred to as an SS-burst-set. The SS-burst-set is also referred to as a transmission window, a SS transmission window, or a DRS transmission window (Discovery Reference Signal transmission window). The SS-burst-set is a generic name that includes at least a first SS-burst-set and a second SS-burst-set.

[0196] For a half frame with SS / PBCH blocks, the first symbol indexes for candidate SS / PBCH blocks are determined according to the SCS of SS / PBCH blocks as follows, where index 0 corresponds to the first symbol of the first slot in a half-frame.

[0197] (Case A) - if the SCS of SS / PBCH blocks is 15 kHz, the first symbols of the candidate SS / PBCH blocks have indexes of {2,8}+14n.- For operation without shared spectrum channel access:- For carrier frequencies smaller than or equal to 3 GHz, n=0,1.- For carrier frequencies within FR1 larger than 3 GHz, n=0,1,2,3.- For operation with shared spectrum channel access, n=0,1,2,3,4.

[0198] (Case B) - if the SCS of SS / PBCH blocks is 30 kHz, the first symbols of the candidate SS / PBCH blocks have indexes {4,8,16,20}+28n. For carrier frequencies smaller than or equal to 3 GHz, n=0. For carrier frequencies within FR1 larger than 3 GHz, n=0,1.

[0199] (Case C) - if the SCS of SS / PBCH blocks is 30 kHz, the first symbols of the candidate SS / PBCH blocks have indexes {2,8}+14n.-For operation without shared spectrum channel access- For paired spectrum operation- For carrier frequencies smaller than or equal to 3 GHz, n=0,1. For carrier frequencies within FR1 larger than 3 GHz, n=0,1,2,3.- For unpaired spectrum operation- For carrier frequencies smaller than 1.88 GHz, n=0,1. For carrier frequencies within FR1 equal to or larger than 1.88 GHz, n=0,1,2,3.- For operation with shared spectrum channel access, n=0, 1,2, 3, 4, 5, 6, 7, 8, 9.

[0200] (Case D) - if the SCS of SS / PBCH blocks is 120 kHz, the first symbols of the candidate SS / PBCH blocks have indexes {4,8,16,20}+28n. For carrier frequencies within FR2, n=0, 1,2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18.

[0201] (Case E) - if the SCS of SS / PBCH blocks is 240 kHz, the first symbols of the candidate SS / PBCH blocks have indexes {8,12,16,20,32,36,40,44}+56n. For carrier frequencies within FR2-1, n=0,1,2,3,5,6,7,8.

[0202] (Case F) - if the SCS of SS / PBCH blocks is 480 kHz SCS, the first symbols of the candidate SS / PBCH blocks have indexes {2,9}+14 n. For carrier frequencies within FR2-2, n = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31.

[0203] (Case G) - if the SCS of SS / PBCH blocks is 960 kHz, the first symbols of the candidate SS / PBCH blocks have indexes {2,9}+14 n. For carrier frequencies within FR2-2, n = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31.

[0204] From the above cases, if the SCS of SS / PBCH blocks is not provided by RRC parameter (ssbSubcarrierSpacing), the applicable cases for a cell depend on a respective frequency band. A same case applies for all SS / PBCH blocks on the cell.

[0205] The BS 3 transmits SS / PBCH blocks of one or more indexes at a predetermined cycle. The terminal device 1 may detect an SS / PBCH block of at least one of the SS / PBCH blocks of the one or more indexes. The terminal device 1 may attempt to decode the PBCH included in the SS / PBCH block.

[0206] The terminal device 1 assumes that reception occasions of a PBCH, PSS, and SSS are in consecutive symbols, and form a SS / PBCH block. The terminal device 1 assumes that SSS, PBCH DM-RS, and PBCH data have same EPRE. The terminal device 1 may assume that the ratio of PSS EPRE to SSS EPRE in a SS / PBCH block is either OdB or 3dB. If the terminal device 1 has not been provided dedicated higher layer parameters, the terminal device 1 may assume that the ratio of PDCCH DMRS EPRE to SSS EPRE is within -8 dB and 8 dB when the terminal device 1 monitors PDCCHs for a DCI format l_0 with CRC scrambled by SI-RNTI, P-RNTI, or RA-RNTI, or for a DCI format 2_7, or for a DCI format 4_0.

[0207] For a half frame with SS / PBCH blocks, the first symbol indexes for candidate SS / PBCH blocks are determined according to the SCS of SS / PBCH blocks.

[0208] The terminal device 1 can be provided per serving cell by ssb-periodicityServingCell a periodicity of the half frames for reception of the SS / PBCHblocks for the serving cell. If the terminal device 1 is not configured a periodicity of the half frames for receptions of the SS / PBCH blocks, the terminal device 1 assumes a periodicity of a half frame. The terminal device 1 assumes that the periodicity is same for all SS / PBCH blocks in the serving cell.

[0209] Figure 9 is a diagram showing an example of SS / PBCH block transmission for 15 kHz SCS with carrier frequencies larger than 3 GHz. In this case, there are 8 SSB candidate positions in a half frame, and the half frame with SS / PBCH blocks is repeated every SSB periodicity (e.g. 20ms). The base station 3 transmits SS / PBCH blocks on one or more SSB candidate positions. The candidate positions where the base station 3 use for SSB transmission are indicated to the terminal device 1 by higher layer parameter (ssb-PositionsInBurst). The ssb-PositionsInBurst indicates the time domain positions of the transmitted SS-blocks in a half frame with SS / PBCH blocks as bitmap. The first / leftmost bit corresponds to SS / PBCH block index 0 (SSB candidate position 1 in Figure 9), the second bit corresponds to SS / PBCH block index 1 (SSB candidate position 2 in Figure 9), and so on. Value 0 in the bitmap indicates that the corresponding SS / PBCH block is not transmitted while value 1 indicates that the corresponding SS / PBCH block is transmitted. The periodicity where the base station 3 use for SSB transmission are indicated to the terminal device 1 by higher layer parameter (ssb-PeriodicityServingCell). The ssb-PeriodicityServingCell indicates the SSB periodicity in ms for the rate matching purpose. If the field for ssb-PeriodicityServingCell is absent, the terminal device 1 applies the value 5 ms.

[0210] For initial cell selection, the terminal device 1 may assume that half frames with SS / PBCH blocks occur with a periodicity of 2 frames.

[0211] The Master Information Block (MIB) on PBCH provides the terminal device 1 with parameters (e.g. CORESET#0 configuration) for monitoring of PDCCH for scheduling PDSCH that carries System Information Block 1 (SIB1). PBCH may also indicate that there is no associated SIB1, in which case the UE may be pointed to another frequency from where to search for an SSB that is associated with a SIB1 as well as a frequency range where the UE may assume no SSB associated with SIB1 is present. The indicated frequency range is confined within a contiguous spectrum allocation of the same operator in which SSB is detected. PBCH may also indicate that associated SIB is absent (there is no associated SIB1 on that time), in which case the terminal device 1 may be provided the configuration for SIB1 request (uplink wakeup signal: UL-WUS) by MIB information or by other information.

[0212] The random-access is a procedure including at least a part or all of message 1, message 2, message 3, and message 4.

[0213] The message 1 (Msgl, Msg 1) is a procedure (or transmitted signal / channel itself for the procedure) in which the terminal device 1 transmits one or plurality of PRACH. The terminal device 1 transmits one PRACH (one random access preamble) in one PRACH occasion (RO: RACH occasion) selected from among one or more ROs based on at least the index of the SS / PBCH block candidate detected based on the cell search. The terminal device 1 may transmit a plurality of PRACHs using a plurality of ROs (can be referred as RO group) selected from among one or more ROs based on at least the index of the SS / PBCH block candidate detected based on the cell search. The RO is a resource in time and frequency domain to transmit a random access preamble.

[0214] When one or a plurality of ROs are configured by higher layer, the terminal device 1 and / or the BS3 assume that a part or all of the one or a plurality of ROs are assumed to be valid ROs with following conditions.

[0215] For paired spectrum (i.e. FDD), or supplementary uplink band, all ROs are assumed to be valid RO.

[0216] For unpaired spectrum, (1) if the terminal device 1 is not provided higher layer parameter tdd-UL-DL-ConfigurationCommon, a RO in a PRACH slot is assumed to be valid RO if it does not precede a SS / PBCH block in the PRACH slot and starts at least Ngapsymbols after a last SS / PBCH block reception symbol, where Ngapis predetermined; (2) if a UE is provided the tdd-UL-DL-ConfigurationCommon, a RO in a PRACH slot is assumed to be valid RO if it is within UL symbols, or if it does not precede a SS / PBCH block in the PRACH slot and starts at least Ngapsymbols after a last downlink symbol and at least Ngapsymbols after a last SS / PBCH block symbol.

[0217] The message 2 (Msg2, Msg 2) is a procedure (or transmitted signal / channel itself for the procedure) in which the terminal device 1 attempts to detect a DCI format l_0 with CRC (Cyclic Redundancy Check) scrambled by an RA-RNTI (Random Access-Radio Network Temporary Identifier). The terminal device 1 may attempt to monitor RA response(s) during the time window called as RAR window. The terminal device 1 may attempt to detect the DCI format l_0 in a search-space-set while the RAR window is running.

[0218] The message 3 (Msg3, Msg 3) is a procedure (or transmitted signal / channel itself for the procedure) for transmitting a PUSCH scheduled by a random-access response grant included in the DCI format l_0 detected in the message 2 procedure. Therandom-access response grant is indicated by the MAC CE included in the PDSCH scheduled by the DCI format l_0.

[0219] The PUSCH scheduled based on the random-access response grant is either a message 3 PUSCH or a PUSCH. The message 3 PUSCH contains a contention resolution identifier MAC CE. The contention resolution ID MAC CE includes a contention resolution ID.

[0220] Retransmission of the message 3 PUSCH is scheduled by DCI format 0_0 with CRC scrambled by a TC-RNTI (Temporary Cell-Radio Network Temporary Identifier).

[0221] The message 4 (Msg4, Msg 4) is a procedure (or transmitted signal / channel itself for the procedure) that attempts to detect a DCI format l_0 with CRC scrambled by either a C-RNTI (Cell-Radio Network Temporary Identifier) or a TC-RNTI. The terminal device 1 receives a PDSCH scheduled based on the DCI format l_0. The PDSCH may include a collision resolution ID.

[0222] Data communication is a generic term for downlink communication and uplink communication.

[0223] In data communication, the terminal device 1 attempts to detect a PDCCH (attempts to monitor a PDCCH, monitors a PDCCH) in a resource identified at least based on one or all of a control resource set (CORESET) and a search-space-set. It’s also called as “the terminal device 1 attempts to detect a PDCCH in a control resource set”, “the terminal device 1 attempts to detect a PDCCH in a search-space-set”, “the terminal device 1 attempts to detect a PDCCH candidate in a control resource set”, “the terminal device 1 attempts to detect a PDCCH candidate in a search-space-set’ ’, “the terminal device 1 attempts to detect a DCI format in a control resource set”, or “the terminal device 1atempts to detect a DCI format in a search-space-set”. Monitoring a PDCCH may be equivalent as monitoring a DCI format in the PDCCH.

[0224] The control resource set (CORESET) is a set of resources configured by the number of resource blocks and a predetermined number of OFDM symbols in a slot. A CORESET consists of a set of PRBs with a time duration of 1 to 3 OFDM symbols. The resource units Resource Element Groups (REGs) and Control Channel Elements (CCEs) are defined within a CORESET with each CCE consisting a set of REGs. Control channels are formed by aggregation of CCE. Different code rates for the control channels are realized by aggregating different number of CCE. Interleaved and non-interleaved CCE-to-REG mapping are supported in a CORESET. The terminal device 1 monitors a set of PDCCH candidates in the configured monitoring occasions in one or more configured CORESETs according to the corresponding search space configurations.

[0225] The set of resources for the control resource set may be indicated by higher-layer parameters. The number of OFDM symbols included in the control resource set may be indicated by higher-layer parameters.

[0226] A PDCCH may be also called as a PDCCH candidate.

[0227] A search-space-set is defined as a set of PDCCH candidates. A search-space-set may be a Common Search Space (CSS) set or a UE-specific Search Space (USS) set.

[0228] The CSS set is a generic name of a type-0 PDCCH CSS set, a type-Oa PDCCH CSS set, a type-1 PDCCH CSS set, a type-2 PDCCH CSS set, and a type-3 PDCCH CSS set. The USS set may be also called as UE-specific PDCCH search-space-set.

[0229] The type-0 PDCCH CSS may be used as a common search-space-set (CSS set) with index 0. The type-0 PDCCH CSS set may be a common search-space-set with index 0. The type-0 PDCCH Common Search Space is a subset of PDCCH Search Spacethat is dedicated to transmit the PDCCH for SI message (SIB). The type-0 PDCCH CSS set may be a common search-space-set to transmit the PDCCH scheduling SIB1.

[0230] A search-space-set is associated with (included in, corresponding to) a control resource set. The index of the control resource set associated with the search-space-set may be indicated by higher-layer parameters.

[0231] For a search-space-set, a part or all of 6A to 6C may be indicated at least by higher-layer parameters. The 6A is PDCCH monitoring period. The 6B is PDCCH monitoring pattern within a slot. The 6C is PDCCH monitoring offset.

[0232] A monitoring occasion of a search-space-set may correspond to one or more OFDM symbols in which the first OFDM symbol of the control resource set associated with the search-space-set is allocated. A monitoring occasion of a search-space-set may correspond to resources identified by the first OFDM symbol of the control resource set associated with the search-space-set. A monitoring occasion of a search-space-set is given based at least on a part or all of PDCCH monitoring periodicity, PDCCH monitoring pattern within a slot, and PDCCH monitoring offset.

[0233] Figure 10 is a diagram showing an example of the monitoring occasion of the search-space-set. In Figure 10, the search-space-set 91 and the search-space-set 92 are sets in the primary cell 301, the search-space-set 93 is a set in the secondary cell 302, and the search-space-set 94 is a set in the secondary cell 303.

[0234] In Figure 10, the block indicated by the grid line indicates the search-space-set 91, the block indicated by the upper right diagonal line indicates the search-space-set 92, the block indicated by the upper left diagonal line indicates the search-space-set 93, and the block indicated by the horizontal line indicates the search-space-set 94.

[0235] In Figure 10, the PDCCH monitoring periodicity for the search-space-set 91 is set to 1 slot, the PDCCH monitoring offset for the search-space-set 91 is set to 0 slot, and the PDCCH monitoring pattern for the search-space-set 91 is [1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0]. That is, the monitoring occasion of the search-space-set 91 corresponds to the first OFDM symbol (OFDM symbol # 0) and the eighth OFDM symbol (OFDM symbol # 7) in each of the slots.

[0236] In Figure 10, the PDCCH monitoring periodicity for the search-space-set 92 is set to 2 slots, the PDCCH monitoring offset for the search-space-set 92 is set to 0 slots, and the PDCCH monitoring pattern for the search-space-set 92 is [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]. That is, the monitoring occasion of the search-space-set 92 corresponds to the leading OFDM symbol (OFDM symbol # 0) in each of the even slots.

[0237] In Figure 10, the PDCCH monitoring periodicity for the search-space-set 93 is set to 2 slots, the PDCCH monitoring offset for the search-space-set 93 is set to 0 slots, and the PDCCH monitoring pattern for the search-space-set 93 is [0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0]. That is, the monitoring occasion of the search-space-set 93 corresponds to the eighth OFDM symbol (OFDM symbol # 8) in each of the even slots.

[0238] In Figure 10, the PDCCH monitoring periodicity for the search-space-set 94 is set to 2 slots, the PDCCH monitoring offset for the search-space-set 94 is set to 1 slot, and the PDCCH monitoring pattern for the search-space-set 94 is [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]. That is, the monitoring occasion of the search-space-set 94 corresponds to the leading OFDM symbol (OFDM symbol # 0) in each of the odd slots.

[0239] The type-0 PDCCH CSS set may be at least used for a DCI format with a cyclic redundancy check (CRC) sequence scrambled by an SI-RNTI (System Information-Radio Network Temporary Identifier).

[0240] SI-RNTI is used for broadcast of system information. It is a common RNTI meaning that, it is not allocated to any UE explicitly and common to all UEs in the cell. SI-RNTI is of 16-bit in length and its value may be fixed to 65535 (OxFFFF). A single SI-RNTI is used to address all SI messages. Broadcast of System Information uses BCCH logical channel which is then mapped to DL-SCH transport channel which intern mapped to PDSCH physical channel. The terminal devices 1 should know the scheduling information for PDSCH which is carrying System Information. The required scheduling information is contained in DCI (Downlink Control Information) whose CRC is scrambled by SI-RNTI. The terminal device 1 starts decoding PDCCH scrambled with SI-RNTI at the start of SI Window (for the concerned SI message) until the end of the SI window, or until the SI message was received excluding the following subframes.

[0241] The type-Oa PDCCH CSS set may be used at least for a DCI format with a cyclic redundancy check sequence scrambled by an SI-RNTI.

[0242] The type-1 PDCCH CSS set may be used at least for a DCI format with a CRC sequence scrambled by an RA-RNTI (Random Access-Radio Network Temporary Identifier) or a CRC sequence scrambled by a TC-RNTI (Temporary Cell-Radio Network Temporary Identifier).

[0243] TC-RNTI is used during Random Access procedure, the base station 3’s MAC generates Random Access Response (RAR) as a response to the Random Access Preamble transmitted by the terminal device 1. The MAC RAR contains TC-RNTI. During contention based random access procedure, the terminal device 1 stores received TC-RNTI (received in RAR) and uses it during random access procedure. The terminal device 1 shall discard the TC-RNTI value received in RAR during non-contention based random access procedure. The terminal device 1 shall use TC-RNTI for scrambling ofmsg3 (PUSCH corresponding to RAR grant) and its retransmissions. During contention based RA procedure, the terminal device 1 monitors PDCCH scrambled with TC-RNTI. The TC-RNTI is promoted to C-RNTI for a terminal device 1 which detects RA success and does not already have a C-RNTI.

[0244] The type-2 PDCCH CSS set may be used for a DCI format with a CRC sequence scrambled by P-RNTI (Paging-Radio Network Temporary Identifier).

[0245] P-RNTI is used by the terminal devices 1 for the reception of paging. It is common RNTI meaning that it is not allocated to any terminal device 1 explicitly. P-RNTI is of 16-bit in length and its value may be fixed to 65534 (OxFFFE). Paging message is carried by PCCH logical channel which is mapped to PCH transport channel. The PCH transport channel is mapped to PDSCH physical channel. The base station 3 scrambles PDCCH’s CRC with P-RNTI for transmission of PDSCH that carries paging information DCI Formats which carries scheduling information for paging.

[0246] The type-3 PDCCH CSS set may be used for a DCI format with a CRC sequence scrambled by a C-RNTI (Cell-Radio Network Temporary Identifier).

[0247] C-RNTI is a unique identification used for identifying RRC Connection and scheduling which is dedicated to a particular terminal device 1. The base station 3 assigns different C-RNTI values to different terminal devices 1. The base station 3 uses C-RNTI to allocate a terminal device 1 with uplink grants, downlink assignments, etc. C-RNTI is used by base station 3 to differentiate uplink transmissions (e.g. PUSCH, PUCCH) of a terminal device 1 from others.

[0248] The UE-specific search-space-set (USS set) may be used at least for a DCI format with a CRC sequence scrambled by a C-RNTI.

[0249] In downlink communication, the terminal device 1 may detect a downlink DCI format. The detected downlink DCI format is at least used for resource assignment for a PDSCH. The detected downlink DCI format is also referred to as downlink assignment. The terminal device 1 attempts to receive the PDSCH. Based on a PUCCH resource indicated based on the detected downlink DCI format, an HARQ-ACK corresponding to the PDSCH (HARQ-ACK corresponding to a transport block included in the PDSCH) may be reported to the BS 3.

[0250] In uplink communication, the terminal device 1 may detect an uplink DCI format. The detected uplink DCI format is at least used for resource assignment for a PUSCH. The detected uplink DCI format is also referred to as uplink grant. The terminal device 1 transmits the PUSCH.

[0251] PUSCH transmission(s) can be dynamically scheduled by an UL grant in a DCI, or the transmission can correspond to a configured grant Type 1 or Type 2. The configured grant Type 1 PUSCH transmission is semi-statically configured to operate upon the reception of higher layer parameter of configuredGrantConfig including rrc-ConfiguredUplinkGrant without the detection of an UL grant in a DCI. The configured grant Type 2 PUSCH transmission is semi-persistently scheduled by an UL grant in a valid activation DCI according to those procedure(s) after the reception of higher layer parameter configuredGrantConfig not including rrc-ConfiguredUplinkGrant. If configuredGrantConfigToAddModList is configured, more than one configured grant configuration of configured grant Type 1 and / or configured grant Type 2 may be active at the same time on an active BWP of a serving cell.

[0252] The random access procedure may include a contention-based random access (CBRA) procedure and a contention-free random access (CFRA) procedure.

[0253] The random access procedure may be initiated by a PDCCH order, by the MAC entity itself, or by RRC. There is only one random access procedure ongoing at any point in time in a MAC entity. The random access procedure on an SCell shall only be initiated by a PDCCH order.

[0254] The random access procedure may have two random access (RA) type which are 4-step RAtype (can be called as Type-1 random access procedure) and 2-step RAtype (can be called as Type-2 random access procedure).

[0255] Prior to initiation of a physical random access procedure, Layer 1 of the terminal device 1 receives from higher layers a set of SS / PBCH block indexes and provides to higher layers a corresponding set of RSRP measurements.

[0256] Prior to initiation of the physical random access procedure, Layer 1 of the terminal device 1 may receive from higher layers an indication to perform a Type-1 random access procedure, or a Type-2 random access procedure.

[0257] From the physical layer perspective, the Type-1 random access procedure includes the transmission of random access preamble (Msgl) in a PRACH, random access response (RAR) message with a PDCCH / PDSCH (Msg2), and when applicable, the transmission of a PUSCH scheduled by a RAR UL grant, and PDSCH for contention resolution.

[0258] From the physical layer perspective, the Type-2 random access procedure includes the transmission of random access preamble in a PRACH and of a PUSCH (MsgA) and the reception of a RAR message with a PDCCH / PDSCH (MsgB), and when applicable, the transmission of a PUSCH scheduled by a fallback RAR UL grant, and PDSCH for contention resolution.

[0259] If a random access procedure is initiated by a PDCCH order to the terminal device 1, a PRACH transmission is with a same SCS as a PRACH transmission initiated by higher layers.

[0260] If the terminal device 1 is configured with two UL carriers for a serving cell and the terminal device 1 detects a PDCCH order, the terminal device 1 uses the UL / SUL indicator field value from the detected PDCCH order to determine the UL carrier for the corresponding PRACH transmission.

[0261] Prior to initiation of the physical random access procedure, Layer 1 of the terminal device 1 receives the following information from the higher layers:

[0262] - Configuration of PRACH transmission parameters (e.g. PRACH preamble format, time resources, and frequency resources for PRACH transmission).

[0263] - Parameters for determining the root sequences and their cyclic shifts in the PRACH preamble sequence set (index to logical root sequence table, cyclic shift, and set type (unrestricted, restricted set A, or restricted set B)).

[0264] Following RRC parameters for the random access procedure may be configured by RRC (can be by system information or by dedicated RRC signalling).

[0265] RACH-ConfigCommon is used to specify the cell specific random access parameters. For a cell, Different RACH-ConfigCommon (can be called as RACK configuration and one or more of additional RACH configurations) are provided by an RRC parameter to specify the random access parameters for different features and / or different feature combinations such as single PRACH transmission, mutiple PRACH transmissions, RedCap and so on. The one or more of additional RACH configurations may be provided as a list of RACH configurations. Each RACH configuration included in the list may be RACH-ConfigCommon. The terminal device 1 may receive the list ofRACH configurations. The base station 3 may transmit the list of RACH configurations. Each RACH-ConfigCommon may include rach-ConfigGeneric, ssb-perRACH-OccasionAndCB-PreamblesPerSSB, rsrp-ThresholdSSB and featureCombinationPreamblesList. Each RACH configuration may be associated with the feature combinations indicated by the featureCombinationPreamblesList. Each RACH configuration may be associated with a feture or a feature combination. Each RACH configuration may be associated with one or multiple fetures or one or more multiple feature combinations. The terminal device 1 and / or the base station 3 may identify multiple PRACH occasions (RACH occasions, ROs) based on the RACH configuration. Figure 11 shows an example of parameter structure of RACH-ConfigCommon and RACH-ConfigGeneric which is an information element for rach-ConfigGeneric.

[0266] The parameter rach-ConfigGeneric indicates generic RACH parameters including prach-ConfigurationIndex, msg1-FDM and msg1-FrequencyStart, zeroCorrelationZoneConfig, preambleReceivedTargetPower, preambleTransMax, powerRampingStep and ra-ResponseWindow.

[0267] The parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB defines the number of SSBs mapped to each RO for 4-step RA type and the number of contentionbased Random Access Preambles mapped to each SSB.

[0268] prach-ConfigurationIndex indicates the available set of ROs for the transmission of the random access preamble for Msg1. These are also applicable to the MsgA PRACH if the ROs are shared between 2-step and 4-step RA types.

[0269] The parameter msg1-FDM indicates the number of ROs FDMed in one time instance.

[0270] The parameter msg1-FrequencyStart indicates offset of lowest RO in frequency domain with respective to PRB 0. The value is configured so that the corresponding RACH resource is entirely within the bandwidth of the UL BWP.

[0271] The parameter preambleReceivedTargetPower indicates initial random access preamble power for 4-step RA type.

[0272] The parameter rsrp-ThresholdSSB indicates an RSRP threshold for the selection of the SSB for 4-step RA type, the rsrp-ThresholdSSB may be used for the UE to select an SSB from one or more SSBs and corresponding PRACH resources for path-loss estimation and (re)transmission based on the SSB that satisfies a threshold indicated by the rsrp-ThresholdSSB. The rsrp-ThresholdSSB may be included in the PRACH configuration information. The rsrp-ThresholdSSB may be considered as a parameter indicating an RSRP threshold to determine the number of PRACHs to transmit within a RACH attempt (can be referred as the number of PRACH repetition or number of preamble repetitions). When there is at least one available SSB with RSRP above the threshold configured by rsrp-ThresholdSSB, the terminal device 1 may perform PRACH transmission without repetition (i.e. one PRACH can be transmitted within a RACH attempt.)

[0273] The parameter rsrp-ThresholdCSI-RS indicates an RSRP threshold for the selection of CSI-RS for 4-step RA type.

[0274] The parameter powerRampingStep indicates the power-ramping factor.

[0275] The parameter ra-Preamblelndex indicates a random access preamble;

[0276] The parameter ra-ssb-OccasionMasklndex defines RO(s) associated with an SSB in which the MAC entity may transmit a random access preamble.

[0277] The parameter ra-OccasionList defines RO(s) associated with a CSI-RS in which the MAC entity may transmit a random access preamble.

[0278] The parameter preambleTransMax indicates the maximum number of random access preamble transmission.

[0279] The parameter number OfPreamblesForThisPartition indicates the number of consecutive preambles associated with the set of random access resources applicable to the random access procedure.

[0280] The parameter ra-Response Window indicates the time window to monitor RA response(s).

[0281] The parameter ra-ContentionResolutionTimer indicates the Contention Resolution Timer.

[0282] The parameter featureCombinationPreamblesList specifies a series of preamble partitions each associated to a combination of features as FeatureCombinationPreambles.

[0283] The parameter FeatureCombinationPreambles associates a set of preambles with a feature combination. For parameters which can be provided in this parameter, the terminal device 1 applies the value when performing random access using a preamble in this featureCombinationPreambles. The featureCombinationPreambles may include featureCombination, startPreambleForThisPartition, number OfPreamblesP er SSB- ForThisPartition, ssb-SharedRo-Masklndex, rsrp-ThresholdSSB, deltaPreamble and prach-RepetitionConfig. Figure 12 shows an example of parameter constructure of featureCombinationPreambles and featureCombination. The terminal device 1 may receive FeatureCombinationPreambles including featureCombination to specify a RACK resource for a feature combination. The base station 3 may transmitFeatureCombinationPreambles including featureCombination to specify a RACH resource for a feature combination.

[0284] The parameter featureCombination indicates which combination of features that the preambles indicated by this parameter are associated with. The terminal device 1 ignores a RACH resource defined by this FeatureCombinationPreambles if any feature within the featureCombination is not supported by the terminal device 1 or has an unknown value. As shown in figure 12, featureCombination can include redCap, smallData, nsag, msg3-Repetitions, prach-Repetitions, spare3, spare2 and spare 1.

[0285] If the redCap is present in featureCombination, the redCap indicates that RedCap is part of this feature combination.

[0286] If the smallData is present in featureCombination, the smallData indicates that Small Data is part of this feature combination.

[0287] If the nsag is present in featureCombination, the nsag indicates NSAG(s) that are part of this feature combination.

[0288] If the msg3-Repetitions is present in featureCombination, the msg3-Repetitions indicates that signalling of msg3 repetition is part of this feature combination.

[0289] If the prach-Repetitions is present in featureCombination, the prach-Repetitions indicates that PRACH repetition is part of this feature combination. Alternatively, the prach-Repetitions may be configured by the list of PRACH repetitions with repetition number. If a PRACH repetition with a certain repetition number is included in the list, the PRACH repetition with the repetition number is part of this feature combination. When the terminal device 1 performs the PRACH repetition, the terminal device 1 specifies / determines RACH resources including random access preambles and ROs based on the featureCombinationPreambles and featureCombination with prach-Repetitions. The terminal device 1 may receive one or plurality of repetition numbers which are associated with a RACH configuration (e.g. rach-ConfigCommon) by the prach-Repetitions. The base station 3 may transmit one or plurality of repetition numbers which are associated with a RACH configuration (e.g. rach-ConfigCommon) by the prach-Repetitions.

[0290] spare3, spare2 and spare1 are spare parameters.

[0291] The terminal device 1 may use following variables for the random access procedure.

[0292] PREAMBLE_TRANSMISSION_COUNTER (can be referred as a preamble transmission counter) is used to count the number of attempts of a preamble transmission.

[0293] PREAMBLE POWER RAMPING COUNTER (can be referred as a power ramping counter) is used to count the number of power ramping which increase the transmission power of the preamble transmission.

[0294] PREAMBLE_POWER_RAMPING_STEP is used to storage the step size of power ramping.

[0295] PREAMBLE_RECEIVED_TARGET_POWER is used to storage the received target power of a preamble transmission.

[0296] TEMPORARY_C-RNTI is used to storage the temporary C-RNTI.

[0297] RA_TYPE is used to storage the RA type.

[0298] MSGA PREAMBLE POWER RAMPING STEP is used to storage the step size of power ramping for 2-step RA.

[0299] When the random access procedure is initiated on a serving cell, the terminal device 1 (can be MAC entity of the terminal device 1) sets thePREAMBLE TRANSMISSION COUNTER to 1 and sets the PREAMBLE_POWER_RAMPING_COUNTER to 1.

[0300] When the terminal device 1 performs 4-step RA procedure (RA_TYPE is set to 4-stepRA), the terminal device 1 set PREAMBLE POWER RAMPING STEP to power RampingStep which is higher layer parameter provided by RRC.

[0301] Physical random access procedure for the terminal device 1 is triggered upon request of a PRACH transmission by higher layers or by a PDCCH order for a cell. A configuration by higher layers for a PRACH transmission may include the following:

[0302] - A configuration for PRACH transmission on the cell.

[0303] - A preamble index, a preamble subcarrier spacing (SCS), PPRACH, target,acorresponding RA-RNTI when applicable, and a PRACH resource for the cell.

[0304] - A number of Nreppreamble> 1 preamble repetitions for the PRACH transmission if the terminal device 1 would transmit the PRACH with repetitions (can be referred as PRACH repetition or preamble repetitions).

[0305] The preamble repetitions are multiple random access preamble transmissions, each of the multiple random access preamble transmissions is transmitted on a PRACH occasion (RO).

[0306] The terminal device 1 transmits a PRACH on a cell using the selected PRACH format with transmission power PPRACH,b,f,c(i) on the indicated PRACH resource or on determined Nreppreambleresources (NreppreamblePRACH occasions) using the same Tx spatial filter in case of ANreppreamblepreamble repetitions.

[0307] For Type-1 random access procedure, the terminal device 1 is provided a number N of SS / PBCH block indexes associated with one PRACH occasion and anumber R of contention based preambles per SS / PBCH block index per valid RO by ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0308] Figure 13 is a diagram illustrating an example of a contention-based random access (CBRA) procedure of the terminal device 1 according to the present embodiment.

[0309] In 1101, the terminal device 1 transmits a random access preamble to the BS (BS) 3 via a PRACH. The transmitted random access preamble may be referred to as a message 1 (Msgl, Msg 1). The transmission of the random access preamble will also be referred to as PRACH transmission. The random access preamble is configured to notify information to the BS 3 using one sequence among a plurality of sequences. For example, 64 types (the numbers of random access preamble indexes range from 1 to 64) of sequences are prepared. In a case that 64 types of sequences are prepared, it is possible to indicate 6-bit information (which may be ra-Preamblelndex or a preamble index) for the BS 3. The information may be indicated as a random access preamble identifier (Random Access Preamble Identifier, RAPID).

[0310] For a Msgl procedure (can be referred as a PRACH attempt), the terminal device 1 may transmit multiple PRACHs (can be referred as PRACH repetition).

[0311] The terminal device 1 may use same sequence for the multiple PRACHs for a PRACH attempt. The terminal device 1 may use different sequence for the multiple PRACHs for a PRACH attempt.

[0312] For each Msg 1 procedure, the terminal device 1 determines whether to increment the power ramping counter (PREAMBLE_POWER_RAMPING_COUNTER) or not.

[0313] For each preamble transmission (in case of the PRACH repetition, the preamble transmission may be each repetition of the PRACH repetition), the Layer 1 (canbe referred as PHY layer, lower layer) of the terminal device 1 determines whether to notify higher layers (can be referred as MAC layer and / or further higher layers, Layer 2 and / or further higher layers) to suspend the power ramping counter.

[0314] To determine the transmission power of the random access preamble, the terminal device 1 set the PREAMBLE_RECEIVED_TARGET_POWER to preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) * PREAMBLE_POWER_RAMPING_STEP + POWER_OFFSET_2STEP_RA wherein preambleReceivedTargetPower is the higher layer parameter signaled by RRC, DELTA PREAMBLE is the variable which is determined based on a format used for the PRACH, and POWER_OFFSET_2STEP_RA is the power offset variable which is applied when RA_ TYPE is switched from 2-stepRA to 4-stepRA during this random access procedure.

[0315] The MAC entity (MAC layer processing unit 15) of the terminal device 1 instruct the physical layer (physical layer processing unit 10 of the terminal device 1) to transmit the random access preamble using the PREAMBLE_RECEIVED_TARGET_POWER.

[0316] The physical layer of the terminal device 1 determines a transmission power for a PRACH, on active UL B WP of a carrier of a serving cell based on DL RS for serving cell as PPRACH = min{PcMAX, PREAMBLE_RECEIVED_TARGET_POWER + PL}, wherein PCMAX is the UE configured maximum output power, and PL is a pathloss for the active UL BWP of the carrier based on the DL RS associated with the PRACH transmission on the active DL BWP of the serving cell.

[0317] For a PRACH transmission (or multiple PRACH transmissions in a PRACH attempt), the terminal device 1 apply a spatial domain transmission filter (can be referred as UL transmission beam) for beam forming.

[0318] In a case of a CBRA procedure, an index of a random access preamble is randomly selected by the terminal device 1 itself; In the CBRA procedure, the terminal device 1 selects SS / PBCH blocks that have SS / PBCH block RSRP exceeding a configured threshold value and performs selection of a preamble group. In a case that a relationship between the SS / PBCH block and the random access preamble has been configured, the terminal device 1 randomly selects ra-Preamblelndex from one or a plurality of random access preambles associated with the selected SS / PBCH block and the selected preamble group and sets selected ra-Preamblelndex to the preamble index (PREAMBLE INDEX).

[0319] Based on a dropping rule, the terminal device 1 may drop a preamble transmission for a PRACH transmission. If one or more PRACH transmission(s) of the PRACH repetition in one PRACH attempt are dropped based on the dropping rules, the dropped PRACH transmission(s) is not postponed.

[0320] As the dropping rule, following conditions are considered.- power allocation to PUSCH / PUCCH / PRACH / SRS transmissions with a priority rule - power allocation in EN-DC or NE-DC or NR-DC operation,- slot format determination,- the PUSCH / PUCCH / PRACH / SRS transmission occasions are in the same slot - the gap between a PRACH transmission and PUSCH / PUCCH / SRS transmission is small- DAPS operation- HD-UE operation in paired spectrum- RO masking based on mask index

[0321] If due to the dropping rule above, the terminal device 1 does not transmit a random access preamble for PRACH transmission in a transmission occasion, Layer 1 of the terminal device 1 notifies higher layers to suspend the corresponding power ramping counter. If due to the dropping rule above, the terminal device 1 transmits a random access preamble for PRACH transmission with reduced power in a transmission occasion, Layer 1 of the terminal device 1 may notify higher layers to suspend the corresponding power ramping counter.

[0322] Next, the BS 3 that has received the Msgl 1101 generates a RAR message including an uplink grant (Random Access Response Grant, RAR UL grant) for indicating transmission for the terminal device 1 and transmits a random access response including the generated RAR message to the terminal device 1 in DL-SCH in 1102. In other words, the BS 3 transmits, in the PDSCH in a primary cell, the random access response including the RAR message corresponding to the random access preamble transmitted in 1101. The PDSCH corresponds to a PDCCH including RA-RNTI. This RA-RNTI is calculated by RA-RNTI = 1 + s_id + 14 x t_id + 14 x 80 x f_id + 14 x 80 x 8 x ul_carrier_id. Here, s_id is an index of the first OFDM symbol of the last valid RO corresponding to the PRACH transmission and is a value of 0 to 13. t_id is an index of the first slot of the last valid RO corresponding to the PRACH transmission in the system frame and is a value of 0 to 79. f_id is an index of last valid RO corresponding to the PRACH transmission in the frequency domain and is a value of 0 to 7. ul_carrier_id is an uplink carrier used for Msgl transmission. ul_carrier_id for the NUL carrier is 0 while ul_carrier_id for the SUL carrier is 1. Here, the last valid RO corresponding to the PRACH transmission isirrespective of whether the PRACH transmission on the last valid RO is dropped or not based on some of the dropping rule as described above. For the last valid RO corresponding to the PRACH transmission, the valid RO for the dropped PRACH transmission due to some of the dropping rule should be excluded from the calculation of RA-RNTI. The RA-RNTI is calculated / computed based on a time / frequency location of the last RO of the one or plurality of ROs corresponding to the PRACH transmission which are included in a subset of ROs indicated by a mask index.

[0323] The random access response may be referred to as a message 2 (Msg2, Msg 2) 1102. Also, the BS 3 includes, in the Msg2, a random access preamble identifier corresponding to the received random access preamble and an RAR message (MAC RAR) corresponding to the identifier. The BS 3 calculates a deviation in transmission timing between the terminal device 1 and the BS 3 from the received random access preamble and includes, in the RAR message, transmission timing adjustment information (Timing Advance (TA) command) for adjusting the deviation. The RAR message includes at least a random access response grant field mapped to the uplink grant, a Temporary Cell Radio Network Temporary Identifier (C-RNTI) field to which Temporary C-RNTI is mapped, and a Timing Advance (TA) command. The terminal device 1 adjusts the timing of the PUSCH transmission based on the TA command. The timing of the PUSCH transmission may be adjusted for each cell group. The BS 3 includes, in the Msg2 1102, the random access preamble identifier corresponding to the received random access preamble.

[0324] In order to respond to PRACH transmission, the terminal device 1 detects (monitors) the DCI format l_0 to which a CRC parity bit scrambled with the corresponding RA-RNTI is added, during a time period of a random access response window (RAR window). The time period of the RAR window (window size) is providedby a higher layer parameter ra-ResponseWindow. The window size is the number of slots based on the subcarrier spacing of the Typel-PDCCH common search space. The RAR window starts at the first symbol of the earliest CORESET the terminal device 1 is configured to receive PDCCH for Typel-PDCCH CSS set that is at least one symbol, after the last symbol of the last RO corresponding to the PRACH transmission, where the symbol duration corresponds to the SCS for Typel-PDCCH CSS set. If NUETA,adjor NcommonTA,adjis not zero, the window starts after an additional TTA+ kmacmsec where TTAis predefined and kmacis provided by higher layer parameter kmac or kmac= 0 if kmac is not provided. Here, the last RO corresponding to the PRACH transmission is irrespective of whether the PRACH transmission on the last valid RO is dropped or not based on some of the dropping rule as described above. For the last valid RO corresponding to the PRACH transmission, the valid RO for the dropped PRACH transmission due to some of the dropping rule should be excluded for the starting point of the RAR window.

[0325] In a case that the terminal device 1 detects the DCI format l_0 to which the CRC scrambled with RA-RNTI is added and the PDSCH including one DL-SCH transport block in the RAR window, then the terminal device 1 passes the transport block to the higher layer. The higher layer analyzes the transport block for the random access preamble identifier (RAPID) related to the PRACH transmission. In a case that the higher layer identifies RAPID included in the RAR message of the DL-SCH transport block, the higher layer indicates the uplink grant for the physical layer. The identification means that RAPID included in the received random access response and RAPID corresponding to the transmitted random access preamble are the same. The uplink grant will be referred to as a random access response uplink grant (RAR UL grant) in the physical layer. Inother words, the terminal device 1 can specify the RAR message (MAC RAR) dedicated to itself from the BS 3, by monitoring the random access response (contained in Msg2 1102) corresponding to the random access preamble identifier.

[0326] In a case that the terminal device 1 does not detect the DCI format l_0 to which CRC scrambled with RA-RNTI is added in the RAR window, or (ii) in a case that the terminal device 1 does not properly receive the DL-SCH transport block in the PDSCH in the RAR window, or (iii) in a case that the higher layer does not identify RAPID related to the PRACH transmission, the higher layer provides an indication to transmit the PRACH to the physical layer.

[0327] In a case that the random access preamble identifier corresponding to the transmitted random access preamble is included in the received random access response, and the random access preamble has been selected based on the information received by the terminal device 1 from the BS 3, the terminal device 1 regards the non-contention-based random access procedure as having successfully been completed and transmits the PUSCH based on the uplink grant included in the random access response.

[0328] In a case that the random access preamble identifier corresponding to the transmitted random access preamble is included in the received random access response, and the random access preamble has been selected by the terminal device 1 itself, TC-RNTI is set to the value of the TC-RNTI field included in the received random access response, and the random access Msg3 1103 is transmitted in the PUSCH based on the uplink grant included in the random access response. The PUSCH corresponding to the uplink grant included in the random access response is transmitted in a serving cell in which the corresponding preamble has been transmitted in the PRACH.

[0329] The random access process described in Figure 13 is regarded as a 4-step random access type, which requires two round round-trip transmissions between the terminal device 1 and the BS 3. To further reduce the latency of the random access process, a 2-step random access may be considered.

[0330] For the 2-step random access type, the preamble (Msgl) and the scheduled PUSCH transmission (Msg3) defined in the 4-step type are combined into a single message MsgA. The RAR (Msg2) and the contention resolution message (Msg4) are combined into a single message MsgB.

[0331] The MsgA PRACH preambles are separate from the 4-step random access preambles, but can be transmitted in the same PRACH occasions (ROs) as the preambles of 4-step random access type, or in separate ROs. The PUSCH transmissions are organized into PUSCH occasions (POs) which span multiple symbols and PRBs with optional guard periods and guard bands between consecutive POs. Each PO consists of multiple DMRS ports and DMRS sequences, with each DMRS port / DMRS sequence pair known as PUSCH resource unit (PRU). The 2-step random access type supports at least one-to-one and multiple-to-one mapping between the preambles and PRUs.

[0332] Figure 14 is a diagram illustrating an example of a contention-free random access (CFRA) procedure of the terminal device 1 according to the present embodiment.

[0333] In 1201, the BS 3 transmits a PDCCH order to the terminal device 1 on a PDCCH, and indicates the terminal device 1 to perform a random access procedure. Information indicated by the PDCCH order may include preamble index information, PRACH mask index information, SS / PBCH index information.

[0334] The preamble index information is information indicating one or more preamble indexes out of preamble indexes of available random access preamble indexesindicated by the random access configuration information. Note that, in a case where the preamble index information is a prescribed value, the terminal apparatus 1 may select one random access preamble from one or more available random access preambles at random.

[0335] The PRACH mask index information is information indicating an index of one or more RACH occasions (ROs) associated with the SS / PBCH indicated by “SS / PBCH index” information for the PRACH transmission. Note that a time resource and / or a frequency resource indicated by the PRACH mask index information may be one specific resource or may indicate selectable multiple resources.

[0336] The SS / PBCH index information is information the SS / PBCH that shall be used to determine the RO(s) for the PRACH transmission.

[0337] In 1202, the terminal device 1 that has received the PDCCH order transmits a random access preamble to the BS 3 via a PRACH. The transmitted random access preamble may be referred to as Msgl. The transmission of the random access preamble will also be referred to as PRACH transmission. Note that the terminal device 1 transmits a random access preamble that is indicated in a case where the PDCCH order indicates a preamble index indicating one random access preamble. Note that, in a case where a preamble index indicating a prescribed value is indicated by the PDCCH order, the terminal device 1 may select one random access preamble from available random access preambles at random. Note that, in a case where a PRACH mask index is indicated by the PDCCH order, the terminal device 1 transmits a random access preamble by using a frequency resource and / or a time resource corresponding to the indicated PRACH mask index.

[0338] In 1203, the BS 3 that has received a random access preamble generates a random access response including an uplink grant for indicating the terminal device 1 to performtransmission, and transmits the generated random access response to the terminal device 1 on a PDSCH. The random access response may be referred to as message 2 or Msg 2. The terminal device 1 that has transmitted a random access preamble monitors a PDCCH for the random access response identified by an RA-RNTI, within multiple subframe periods (referred to as RA response windows) after the transmission of the random access preamble. In a case where the terminal device 1 that has transmitted a random access preamble detects a relevant RA-RNTI, the terminal device 1 decodes the random access response mapped to the PDSCH. The terminal device 1 that has successfully decoded the random access response confirms whether or not a random access preamble identifier corresponding to the transmitted random access preamble is included in the random access response. In a case where the random access preamble identifier is included, the terminal device 1 considers the random access procedure successfully completed.

[0339] In CFRA procedure, through transmission and / or reception of the above 3 messages, the terminal device 1 can establish synchronization with the BS 3, and can perform uplink data transmission to the BS 3.

[0340] In a case where the terminal device 1 receives a PDCCH from the BS 3 and the PDCCH includes information indicating initiation of a random access procedure, the terminal device 1 may perform the contention-free random access (CFRA) procedure. Note that the information indicating initiation of a random access procedure may be referred to as a PDCCH order, message 0, Msg.0, or the like. The CFRA procedure is a procedure in which a random access is performed by using a preamble corresponding to a random access preamble index indicated by a PDCCH order from the base station 3. The CFRA procedure is used to promptly establish uplink synchronization between the terminal device 1 and the BS 3 in a case where a handover and a transmission timing ofa terminal device 1 are not valid although the BS 3 and the terminal device 1 are connected, for example. Note that the purpose of the random access is not limited to the above purposes.

[0341] In a case of the CFRA procedure, an index of the random access preamble is selected based on information received by the terminal device 1 from the BS 3. Here, the information received by the terminal device 1 from the BS 3 may be included in the PDCCH. The information can be called as PDCCH order. In a case that all the values of bits of the index of the random access preamble received from the BS 3 are 0, the contention-based random access procedure is executed by the terminal device 1, and the index of the random access preamble is selected by the terminal device 1 itself.

[0342] Hereinafter, the determination of available random access resources (e.g. random access preamble and RO) for PRACH transmission by the terminal device 1 will be described.

[0343] For a random access procedure without any feature combination, the terminal device 1 is provided a number N of SS / PBCH block indexes associated with one PRACH occasion and a number R of contention based preambles per SS / PBCH block index per valid RO by ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0344] For a random access procedure associated with a feature combination indicated by FeatureCombinationPreambles, the terminal device 1 is provided a number N of SS / PBCH block indexes associated with one RO by ssb-perRACH-OccasionAndCB-PreamblesPerSSB and a number S of contention based preambles per SS / PBCH block index per valid RO by startPreambleForThisPartition and numberOfPreamblesPerSSB-ForThisPartition. The PRACH transmission can be on a subset of PRACH occasionsassociated with a same SS / PBCH block index within an SSB-RO mapping cycle for a UE provided with a PRACH mask index by ssb-SharedRO-MaskIndex according to figure 15.

[0345] Figure 15 shows an example of a table of PRACH mask index. The table shows allowed ROs of a SS / PBCH block (SSB) for each PRACH mask index. For example, in case that PRACH mask index 0 is indicated, all valid ROs for a SSB are available for PRACH transmission. For example, in case that PRACH mask index 1-8 is indicated, RO corresponding to PRACH occasion index 1-8 for a SSB is available for PRACH transmission. The ROs are mapped consecutively per corresponding SS / PBCH block index. The indexing of the RO indicated by the mask index value is reset per mapping cycle of consecutive ROs per SS / PBCH block index. The terminal device 1 selects for a PRACH transmission the RO indicated by PRACH mask index value for the indicated SS / PBCH block index in the first available mapping cycle. For example, in case that PRACH mask index 9 or 10 is indicated, every even ROs or every odd ROs for a SSB are available for PRACH transmission.

[0346] Considering this PRACH mask is basically applied per RO, there is some issues to apply the PRACH mask index for a feature combination with PRACH repetition since the PRACH repetition is performed using multiple ROs (RO group). If the PRACH mask is applied for the ROs configured for the PRACH repetitions, a part of the multiple ROs would be masked and dropped in most cases.

[0347] For paired spectrum (a.k.a. frequency division multiplexing: FDD), or supplementary uplink band, all ROs configured by PRACH configuration information are valid RO.

[0348] For unpaired spectrum (a.k.a. time division multiplexing: TDD), if the terminal device 1 is not provided a configuration of configuration for TDD by tdd-UL-DL-ConfigurationCommon, an RO in a PRACH slot is valid if it does not precede a SS / PBCH block in the PRACH slot and starts at least Ngapsymbols after a last SS / PBCH block reception symbol, where Ngapis predefined. If the terminal device 1 is provided tdd-UL-DL-ConfigurationCommon, an RO in a PRACH slot is valid if it is within UL symbols, or it does not precede a SS / PBCH block in the PRACH slot and starts at least Ngapsymbols after a last downlink symbol and at least Ngapsymbols after a last SS / PBCH block symbol.

[0349] SS / PBCH block indexes provided by ssb-PositionsInBurst in SIB 1 or in a higher layer parameter are mapped to valid ROs in the following order- (1) First, in increasing order of preamble indexes within a single RO- (2) Second, in increasing order of frequency resource indexes for frequency multiplexed ROs- (3) Third, in increasing order of time resource indexes for time multiplexed ROs within a PRACH slot- (4) Fourth, in increasing order of indexes for PRACH slots

[0350] An association period, starting from frame 0, for mapping SS / PBCH block indexes to ROs is the smallest value in the set determined by the PRACH configuration period such that N SS / PBCH block indexes are mapped at least once to the ROs within the association period, where the terminal device 1 obtains N from the value of ssb-PositionsInBurst in SIB1 or in a higher layer parameter. If after an integer number of SS / PBCH block indexes to ROs mapping cycles within the association period there is a set of ROs or PRACH preambles that are not mapped to N SS / PBCH block indexes, no SS / PBCH block indexes are mapped to the set of ROs or PRACH preambles. An association pattern period includes one or more association periods and is determined so that a pattern between ROs and SS / PBCH block indexes repeats at most every 160 msec.ROs not associated with SS / PBCH block indexes after an integer number of association periods, if any, are not used for PRACH transmissions.

[0351] Figure 16 is a diagram illustrating an example of allocation of SSB indexes to ROs according to the embodiment of the present invention. Figure 16 illustrates an example of a case in which two PRACH slots are present in a certain time period, two ROs in the time direction and two ROs in the frequency direction are present in one PRACH slot, and SSB indexes 0 to 11 are present. Two SSB indexes are mapped to one RO, the SSB indexes are mapped in accordance with the aforementioned rules (1) to (4), and the SSB indexes are mapped from the SSB index 0 again from the seventh RO.

[0352] In a case that although the SSB indexes are mapped to each RO, all the SSB indexes (all SS / PBCH blocks transmitted by the BS 3) are not mapped even in a case that all the ROs in a PRACH configuration period specified by prach-Configlndex are used, the SSB indexes may be mapped over a plurality of PRACH configuration periods. However, the entire number of SS / PBCH blocks transmitted by the BS 3 may be indicated by a higher layer parameter. The period at which the PRACH configuration period is repeated a predetermined number of times such that all the SSB indexes are mapped at least once will be referred to as an association period. As the number of times the PRACH configuration period configuring the association period is repeated, a minimum value that satisfies the conditions, as mentioned before, in a predefined set of a plurality of values may be used. The predefined set of a plurality of values may be defined for each PRACH configuration period. However, in a case that all the SSB indexes are mapped to the ROs in the association period, and the number of remaining ROs is greater than the number of SS / PBCH blocks, the SSB indexes may be mapped again. However, in a case that all the SSB indexes are mapped to the ROs in the association period, and the number ofremaining ROs is smaller than the number of SS / PBCH blocks, the SSB indexes may not be mapped to the remaining ROs. A cycle at which the ROs are allocated to all the SSB indexes once will be referred to as an SSB index allocation cycle. In a case that SSB-perRACH-Occasion is equal to or greater than 1, each of the SSB indexes is mapped to one RO in one SSB index allocation cycle. In a case that SSB-perRACH-Occasion is a value that is smaller than 1, each SSB index is mapped to 1 / SSB-perRACH-Occasion ROs in one SSB index allocation cycle. The terminal device 1 may specify the association period based on the PRACH configuration period indicated by the PRACH configuration index and the number of SS / PBCH blocks specified by the higher parameter provided by the higher layer (higher layer signal).

[0353] Each of one or a plurality of random access preamble groups included in random access configuration information may be associated for each reference signal (for example, an SS / PBCH block, a CSI-RS, or a downlink transmission beam). The terminal device 1 may select a random access preamble group based on the received reference signal (for example, the SS / PBCH block, the CSI-RS, or the downlink transmission beam).

[0354] However, the random access preamble group associated with each SS / PBCH block may be specified by one or a plurality of parameters notified from the higher layer. The one parameter or one of the plurality of parameters may be one index (for example, a start index) of one or a plurality of available preambles. The one parameter or the one of the plurality of parameters may be the number of preambles that can be used for a contention-based random access per SS / PBCH block. The one parameter or the one of the plurality of parameters may be a total of the number of preambles that can be used for the contention-based random access per SS / PBCH block and the number of preamblesthat can be used for the non-contention-based random access. The one parameter or the one of the plurality of parameters may be the number of SS / PBCH blocks associated with one RO.

[0355] However, the terminal device 1 may receive one or a plurality of downlink signals, each of which is transmitted using one downlink transmission beam, receive random access configuration information associated with one of the downlink signals, and perform the random access procedure based on the received random access configuration information. The terminal device 1 may receive one or a plurality of SS / PBCH blocks in the SS burst set, receive random access configuration information associated with one of the SS / PBCH blocks, and perform the random access procedure based on the received random access configuration information. The terminal device 1 may receive one or a plurality of CRI-RSs, receive random access configuration information associated with one of the CRI-RSs, and perform the random access procedure based on the received random access configuration information. The random access configuration information may be included in system information transmitted by the BS 3 to the terminal device 1.

[0356] One or a plurality of pieces of random access configuration information may include one random access channel configuration (RACH-Config) and / or one physical random access channel configuration ( RACH-Config).

[0357] Parameters related to the random access for each reference signal may be included in the random access channel configuration.

[0358] Parameters (such as an index of PRACH configuration, a RO, and the like) related to the physical random access channel for each reference signal may be included in the physical random access channel configuration.

[0359] The BS 3 transmits an RRC parameter including one or a plurality of pieces of random access configuration information (which may include random access resources) as an RRC message to the terminal device 1.

[0360] The terminal device 1 may select one or a plurality of available random access preambles and / or one or a plurality of available ROs used for the random access procedure based on properties of a transmission path with the BS 3.

[0361] The terminal device 1 may select one or a plurality of available random access preambles and / or one or a plurality of ROs used for the random access procedure based on properties of the transmission path (which may be a RSRP, for example) measured by a reference signal (an SS / PBCH bock and / or a CSI-RS, for example) received from the BS 3.

[0362] To suppress the energy consumption for PRACH (Msgl) monitoring on the base station 3, the base station 3 may perform adaptation of PRACH resources (PRACH occasions).

[0363] For the adaptation of PRACH resources, the base station 3 may configure adaptive PRACH resources (can be referred as additional PRACH resources / second PRACH resources) which can be dynamically activated / deactivated by signalling including DCI signalling, MAC CE signalling and / or RRC signalling.

[0364] The base station 3 may configure the adaptive PRACH resources in addition to semi-static PRACH resources (can be referred as normal PRACH resources / first PRACH resources). The semi-static PRACH resources can be the PRACH resources configured by RACH-ConfigCommon in Figure 11. The adaptive PRACH resources may be used by only UEs with a capability of PRACH adaptation (e.g. NES-capable UEs).

[0365] Figure 17 is a diagram showing an example of adaptation of PRACH resources. In Figure 17(a), before activating the adaptive PRACH resources, only first set of ROs (semi-static PRACH resources) for SSB1 is available for PRACH transmissions. In Figure 17(b), after activating the adaptive PRACH resources, both first set of ROs (semi-static PRACH resources) and second set of ROs (adaptive PRACH resources) for SSB1 is available for PRACH transmissions. In this way, by changing the amount of PRACH resources within the same cell, the base station 3 can monitor the PRACH as frequently as necessary. For example, if there is no terminal device 1 within a cell, the base station 3 use the less amount of PRACH resources (i.e. only semi-static PRACH resources) to save its energy consumption. Then, when the traffic in the cell increase with the number of terminal device 1, the base station 3 use the large amount of PRACH resources (i.e. both semi-static PRACH resources and adaptive PRACH resources) to support PRACH transmissions / receptions with less collision probability.

[0366] The adaptive PRACH resources can be the PRACH resources configured by RACH-ConfigCommon2 in Figure 18.

[0367] Figure 18 shows an example of parameter structure of RACH- ConfigCommon2 configuring the adaptive PRACH resources. The parameters rach-ConfigGeneric, ssb-perRACH-OccasionAndCB-PreamblesPerSSB, rsrp-ThresholdSSB and featureCombinationPreambleList in RACH-ConfigCommon2 have same functionality with same parameters in RACH-ConfigCommon. If each of these parameters is not provided in RACH-ConfigCommon2, the same parameter in RACH-ConfigCommon may be used to configure the adaptive PRACH resources.

[0368] The parameter associationMaskPeriod indicates periodicity N to apply an association period mask index in number of association periods.

[0369] The parameter associationMaskIndex indicates an index of the association period mask which is applied within N association periods configured by the associationMaskPeriod. The association period mask index identifies a time subset of N association periods in which the terminal device 1 can send a random access preamble in the adaptive PRACH resources. The PRACH transmission can be on a set of ROs within the time subset of N association periods indicated by the association period mask index according to Figure 19.

[0370] Figure 19 shows an example of a table of the association period mask index. The table shows association periods which is available for PRACH transmission in adaptive PRACH resources for each association period mask index (associationMaskIndex. In case that association period mask index 0 is indicated, ROs of the adaptive PRACH resources in the first half of N association periods is available for PRACH transmission. In case that association period mask index 1 is indicated, ROs of the adaptive PRACH resources in the second half of A association periods is available for PRACH transmission. In case that association period mask index 2 is indicated, ROs of the adaptive PRACH resources in the first quarter of N association periods is available for PRACH transmission. In case that association period mask index 3 is indicated, ROs of the adaptive PRACH resources in the second quarter of N association periods is available for PRACH transmission. In case that association period mask index 4 is indicated, ROs of the adaptive PRACH resources in the third quarter of N association periods is available for PRACH transmission. In case that association period mask index 5 is indicated, ROs of the adaptive PRACH resources in the fourth quarter of N association periods is available for PRACH transmission. In case that association period mask index 6 is indicated, ROs of the adaptive PRACH resources in the first association period in N association periodsis available for PRACH transmission. In case that association period mask index 7 is indicated, ROs of the adaptive PRACH resources in the (N / 2+1)-th association period in N association periods is available for PRACH transmission. Some index values in the table may be reserved and not be used. The indexing of the association periods indicated by the mask index value is reset per N association periods. The indexing of the association periods indicated by the mask index value may be reset at SFNO. By configuring the length of periodicity (i.e. N) by higher layer signalling (RRC parameter), the granularity of association period masking can be adapted. For example, in case that N = 16 and association period mask index = 0, ROs in consecutive 8 association periods are available and ROs in consecutive 8 association periods are not available. It means the base station 3 can stop PRACH monitoring in the consecutive 8 association periods for network energy saving or for scheduling other signals / channels. On the other hand, in case that N = 2 and association period mask index = 0, ROs in every even association periods are available and ROs in every odd association periods are not available. By configuring the value of N by RRC, the base station 3 can allocate available ROs with high scheduling flexibility for variable traffic conditions.

[0371] In the example shown in Figure 18 and Figure 19, the association mask index (associationMasklndex)' has 8 candidate values and the periodicity for the association mask index N (associationMaskPeriod) has 4 candidate values. The number of candidates for these parameters can be different. For example, the number of candidates for the association mask index (associationMasklndex) may be 4 or 16. For example, the number of candidates for the periodicity for the association mask index N (associationMaskPeriod) may be 2 or 8.

[0372] In this embodiment, the association mask index associationMasklndex) is associated with subset of N association periods based on the table as shown in Figure 19. However, as another embodiment, the association mask index associationMasklndex) may indicate a single association period in N association periods. For example, if the value of the association mask index is n, ROs of the adaptive PRACH resources in n-th association period in the N association periods may be available for PRACH transmission.

[0373] The terminal device 1 with the capability of PRACH adaptation may perform PRACH transmission using an RO included in either of semi-static PRACH resources and adaptive PRACH resources if the adaptive PRACH resources is activated.

[0374] The terminal device 1 without the capability of PRACH adaptation may perform PRACH transmission using an RO included only in semi-static PRACH resources.

[0375] Following random resource selection rule may be used by the terminal devicel.

[0376] If the Random Access procedure was initiated for SpCell beam failure recovery; and if the beamFailureRecoveryTimer (in clause 5.17) is either running or not configured; and if the contention-free Random Access Resources for beam failure recovery request associated with any of the SSBs and / or CSI-RSs have been explicitly provided by RRC; and if at least one of the SSBs with SS-RSRP above rsrp-ThresholdSSB amongst the SSBs in candidateBeamRSList or the CSI-RSs with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the CSI-RSs in candidateBeamRSList is available, the terminal device 1 may select an SSB with SS-RSRP above rsrp-ThresholdSSB amongst the SSBs in candidateBeamRSList or a CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the CSI-RSs in candidateBeamRSList. If CSI-RS is selected, and there is no ra- Preamblelndex associated with the selected CSI-RS, the terminal device 1 set thePREAMBLE_INDEX to a ra-PreambleIndex corresponding to the SSB in candidateBeamRSList which is quasi-colocated with the selected CSI-RS. Otherwise: the terminal device 1 may set the P REAMBLE _INDEX to a ra-Preamblelndex corresponding to the selected SSB or CSI-RS from the set of Random Access Preambles for beam failure recovery request.

[0377] Else if the ra-Preamblelndex has been explicitly provided by PDCCH and if the ra-Preamblelndex is not 0b000000: the terminal device 1 may set the P REAMBLE _INDEX to the signalled ra-Preamblelndex and may select the SSB signalled by PDCCH.

[0378] Elseif the contention-free random access resources associated with SSBs have been explicitly provided in a higher layer parameter and at least one SSB with SS-RSRP above rsrp-ThresholdSSB amongst the associated SSBs is available, the terminal device 1 may select an SSB with SS-RSRP above rsrp-ThresholdSSB amongst the associated SSBs and may set the PREAMBLE_INDEX to a ra-Preamblelndex corresponding to the selected SSB.

[0379] Elseif the contention-free random access resources associated with CSI-RSs have been explicitly provided in a higher layer parameter and at least one CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the associated CSI-RSs is available, the terminal device 1 may select a CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the associated CSI-RSs and may set the PREAMBLE_INDEX to a ra-Preamblelndex corresponding to the selected CSI-RS.

[0380] Elseif the Random Access procedure was initiated for SI request and if the Random Access Resources for SI request have been explicitly provided by RRC: if at least one of the SSBs with SS-RSRP above rsrp-ThresholdSSB is available the terminaldevice 1 may select an SSB with SS-RSRP above rsrp-ThresholdSSB and may select any SSB, otherwise.

[0381] For the CBRA, the terminal device 1 may select an SSB with SS-RSRP above rsrp-ThresholdSSB if at least one of the SSBs with SS-RSRP above rsrp-ThresholdSSB is available and may select any SSB, otherwise. The terminal device 1 may select a random access preamble randomly with equal probability from the random access preambles associated with the selected SSB and the selected random access preambles group. The terminal device 1 may set the PREAMBLE_INDEX to the selected random access preamble.

[0382] The terminal device 1 may determine a RO for PRACH transmission as following.

[0383] If the terminal device 1 selects a SS / PBCH block (SSB) and performs a single PRACH transmission (i.e. not PRACH repetition), the terminal device 1 determines the next available RO from the ROs corresponding to the selected SSB permitted by the restrictions given by the ra-ssb-OccasionMasklndex if configured, or ssb-SharedRO-MaskIndex if configured, and / or associationMasklndex and associationMaskPeriod if configured, or indicated by PDCCH

[0384] If the terminal device 1 has capability for PRACH adaptation and the adaptive PRACH resources are activated, the terminal device 1 determines the next available RO from the semi-static PRACH resources and the adaptive PRACH resources.

[0385] If the terminal device 1 selects a CSI-RS and performs a single PRACH transmission (i.e. not PRACH repetition) and if there is no contention-free random access resource associated with the selected CSI-RS, the terminal device 1 determine the next available RO from the ROs, permitted by the restrictions given by the ra-ssb-OccasionMasklndex if configured, corresponding to the SSB in candidateBeamRSList which is quasi-colocated with the selected CSI-RS. If the terminal device 1 selects a CSI-RS and performs a single PRACH transmission (i.e. not PRACH repetition) and if there is contention-free random access resource associated with the selected CSI-RS, the terminal device 1 determines the next available RO from the ROs in ra-OccasionList corresponding to the selected CSI-RS.

[0386] If the terminal device 1 the terminal device 1 selects a CSI-RS and performs a PRACH repetition, and if there is no contention-free random access resource associated with the selected CSI-RS, the terminal device 1 determine the next available RO group from the RO groups, permitted by the restrictions given by the ra-ssb-OccasionMasklndex if configured, corresponding to the SSB in candidateBeamRSList which is quasi-colocated with the selected CSI-RS. If the terminal device 1 selects a CSI-RS and performs a PRACH repetition and if there is contention-free random access resource associated with the selected CSI-RS, the terminal device 1 determines the next available RO group from the RO groups in ra-OccasionList corresponding to the selected CSI-RS.

[0387] Using the selected random access resources (random access preamble and RO), the terminal device 1 performs the random access preamble transmission procedure.

[0388] The DCI format for PDCCH order may include, in addition to a field indicating random access preamble index and a field indicating SS / PBCH index, a PRACH mask index field for the PRACH transmission.

[0389] The PRACH mask index field may indicate one or more ROs associated with a SSB indicated by SS / PBCH index for the PRACH transmission according to the table provided by figure 15.

[0390] The terminal device 1 may transmit a signal / channel which can be called as PRACH resource modification request (or can be called as uplink wake up signal (UL-WUS)) to require the base station 3 to change / switch / reconfigure the adaptive PRACH resources. If the base station 3 receives the PRACH resource modification request transmitted by the terminal device 1, the base station 3 may change / switch / reconfigure the adaptive PRACH resources.

[0391] In the PRACH resource modification request procedure, the terminal device 1 transmit a PRACH resource modification request signal. The PRACH resource modification request signal may be referred as uplink wake up signal (UL-WUS). The PRACH resource modification request signal may be a preamble. The PRACH resource modification request signal may be a preamble for the PRACH resource modification request. The PRACH resource modification request signal may be the random access preamble. The triggering of the PRACH resource modification request procedure may be the triggering of the random access procedure.

[0392] After transmitting the PRACH resource modification request signal, the terminal device 1 may monitor an acknowledgement for the PRACH resource modification request signal. The acknowledgement for the PRACH resource modification request signal may be Msg2 (or random access response). If the acknowledgement for PRACH resource modification request signal is received, the terminal device 1 may apply the PRACH resource modification (activation of the adaptive PRACH resources) for the PRACH transmission.

[0393] A part of the configuration of the PRACH resource modification request signal may be predetermined. For example, the PRACH resource modification request signal may be transmitted on predetermined time / frequency resource. For example, the resourcefor the PRACH resource modification request signal may be a fixed time / frequency location corresponding to the resource of SS / PBCH block with PBCH for the acquired MIB.

[0394] Figure 13 shows an example of a method for a terminal device 1. The method comprises receiving first information configuring first set of ROs, second information configuring a second set of ROs, and third information including first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs (Step 1001). The method comprises determining available ROs for a PRACH transmission base on the first information, the second information and the third information (Step 1002). In the method, in case that the first set of ROs is deactivated, available ROs may be determined from the second set of ROs, and in case that the first set of ROs is activated, the available ROs may be determined from the first set of ROs included in the time subset per the time periodicity and the second set of ROs. The method comprises transmitting a random access preamble on a random access occasion in the available ROs (Step 1003). The first parameter may show a number of association periods (N) to indicate the time periodicity. The second parameter may show which half or which quarter in the time periodicity the time part is. Each of the first information, the second information and the third information may be signaled to the terminal device 1 by system information, by RRC signalling or by PDCCH. The activation of the first set of ROs is indicated by PDCCH, by RRC signalling or by system information.

[0395] Figure 14 shows an example of a method for a BS 3. The method comprises transmitting first information configuring first set of ROs, second information configuring a second set of ROs, and third information including a first parameterindicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs (Step 2001). The method comprises monitoring a random access preamble on available ROs for a PRACH transmission base on the first information, the second information and the third information (Step 1002). In the method, in case that the first set of ROs is deactivated, the BS 3 may monitor a random access preamble on the second set of ROs, and in case that the first set of ROs is activated, the BS 3 may monitor a random access preamble on the first set of ROs included in the time subset per the time periodicity and on the second set of ROs. The first parameter may show a number of association periods (N) to indicate the time periodicity. The second parameter may show which half or which quarter in the time periodicity the time part is. Each of the first information, the second information and the third information may be signaled from the BS 3 by system information, by RRC signalling or by PDCCH. The activation of the first set of ROs is indicated by PDCCH, by RRC signalling or by system information.

[0396] Each of a program running on the BS 3 and the terminal device 1 according to an aspect of the present invention may be a program that controls a Central Processing Unit (CPU) and the like, such that the program causes a computer to operate in such a manner as to realize the functions of the above-described embodiment according to the present invention. The information handled in these devices is transitorily stored in a Random-Access-Memory (RAM) while being processed. Thereafter, the information is stored in various types of Read-Only-Memory (ROM) such as a Flash ROM and a Hard- Disk-Drive (HDD), and when necessary, is read by the CPU to be modified or rewritten.

[0397] Note that the terminal device 1 and the BS 3 according to the above-described embodiment may be partially achieved by a computer. In this case, this configuration maybe realized by recording a program for realizing such control functions on a computer-readable recording medium and causing a computer system to read the program recorded on the recording medium for execution.

[0398] Note that it is assumed that the "computer system" mentioned here refers to a computer system built into the terminal device 1 or the BS 3, and the computer system includes an OS and hardware components such as a peripheral device. Furthermore, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, and the like, and a storage device built into the computer system such as a hard disk.

[0399] Moreover, the "computer-readable recording medium" may include a medium that dynamically retains a program for a short period of time, such as a communication line that is used to transmit the program over a network such as the Internet or over a communication line such as a telephone line, and may also include a medium that retains a program for a fixed period of time, such as a volatile memory within the computer system for functioning as a server or a client in such a case. Furthermore, the program may be configured to realize some of the functions described above, and also may be configured to be capable of realizing the functions described above in combination with a program already recorded in the computer system.

[0400] Furthermore, the BS 3 according to the above-described embodiment may be achieved as an aggregation (an device group) including multiple devices. Each of the devices configuring such an device group may include some or all of the functions or the functional blocks of the BS 3 according to the above-described embodiment. The device group may include each general function or each functional block of the BS 3.Furthermore, the terminal device 1 according to the above-described embodiment can also communicate with the BS 3 as the aggregation.

[0401] Furthermore, the BS 3 according to the above-described embodiment may serve as an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and / or NG-RAN (Next Gen RAN, NR-RAN). Furthermore, the BS 3 according to the abovedescribed embodiment may have some or all of the functions of a node higher than an eNodeB or the gNB.

[0402] Furthermore, some or all portions of each of the terminal device 1 and the BS 3 according to the above-described embodiment may be typically achieved as an LSI which is an integrated circuit or may be achieved as a chip set. The functional blocks of each of the terminal device 1 and the BS 3 may be individually achieved as a chip, or some or all of the functional blocks may be integrated into a chip. Furthermore, a circuit integration technique is not limited to the LSI, and may be realized with a dedicated circuit or a general-purpose processor. Furthermore, in a case that with advances in semiconductor technology, a circuit integration technology with which an LSI is replaced appears, it is also possible to use an integrated circuit based on the technology.

[0403] Furthermore, according to the above-described embodiment, the terminal device has been described as an example of a communication device, but the present invention is not limited to such a terminal device, and is applicable to a terminal device or a communication device of a fixed-type or a stationary-type electronic device installed indoors or outdoors, for example, such as an Audio-Video (AV) device, a kitchen device, a cleaning or washing machine, an air-conditioning device, office equipment, a vending machine, and other household devices.

[0404] Furthermore, according to the above-described embodiment, the words / parameters described by Italic may be RRC parameter, higher layer parameter, PC5-RRC parameter and / or preconfigured parameter.

[0405] The embodiments of the present invention have been described in detail above referring to the drawings, but the specific configuration is not limited to the embodiments and includes, for example, an amendment to a design that falls within the scope that does not depart from the gist of the present invention. Furthermore, various modifications are possible within the scope of one aspect of the present invention defined by claims, and embodiments that are made by suitably combining technical means disclosed according to the different embodiments are also included in the technical scope of the present invention. Furthermore, a configuration in which constituent elements, described in the respective embodiments and having mutually the same effects, are substituted for one another is also included in the technical scope of the present invention.

Claims

[CLAIMS]1. A user equipment (UE), comprising:reception circuitry configured to receive first information configuring first set of random access occasions (ROs), to receive second information configuring a second set of ROs, and to receive third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs,control circuitry configured to determine, in case that the first set of ROs is deactivated, available ROs from the second set of ROs, and to determine, in case that the first set of ROs is activated, the available ROs from the first set of ROs included in the time subset per the time periodicity and the second set of ROs, andtransmission circuitry configured to transmit a random access preamble on a random access occasion in the available ROs.

2. The UE according to the claim 1: whereinthe first parameter shows a number of association periods to indicate the time periodicity.

3. The UE according to the claim 2: whereinthe second parameter shows which half or which quarter in the time periodicity the time subset is.

4. The UE according to the claim 1: whereinthe reception circuitry receives the first information, the second information and the third information by RRC signalling.

5. The UE according to the claim 1: whereinthe activation of the first set of ROs is indicated by physical downlink control channel.

6. A base station, comprising:transmission circuitry configured to transmit first information configuring first set of random access occasions (ROs), to transmit second information configuring a second set of ROs, and to transmit third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs, reception circuitry configured to monitor, in case that the first set of ROs is deactivated, a random access preamble on the second set of ROs, and to monitor, in case that the first set of ROs is activated, a random access preamble on the first set of ROs included in the time subset per the time periodicity and on the second set of ROs.

7. The base station according to the claim 6: whereinthe first parameter shows a number of association periods to indicate the time periodicity.

8. The base station according to the claim 6: whereinthe second parameter shows which half or which quarter in the time periodicity the time subset is.

9. The base station according to the claim 6: whereinthe transmission circuitry transmits the first information, the second information and the third information by RRC signalling.

10. A method performed by a base station, the method comprising:transmitting first information configuring first set of random access occasions (ROs), transmitting second information configuring a second set of ROs, and transmitting third information including a first parameter indicating a time periodicity and a second parameter indicating which time subset in the time periodicity is available for the first set of ROs, andmonitoring, in case that the first set of ROs is deactivated, a random access preamble on the second set of ROs, and monitoring, in case that the first set of ROs is activated, a random access preamble on the first set of ROs included in the time subset per the time periodicity and on the second set of ROs.

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