CN117296288A

CN117296288A - Method for transmitting HARQ-ACK information, user equipment, processing device, storage medium, method for receiving HARQ-ACK information, and base station

Info

Publication number: CN117296288A
Application number: CN202280034284.9A
Authority: CN
Inventors: 裵德显; 梁锡喆; 金善旭
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2021-05-10
Filing date: 2022-05-10
Publication date: 2023-12-26

Abstract

Based on a first cell slot N scheduled for HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell change, the UE may determine a PUCCH cell from among a plurality of cells including the first cell and a second cell different from the first cell; determining a PUCCH cell slot associated with the first cell slot N from among slots on the PUCCH cell associated with the first cell slot N; and determining a target slot in which the HARQ-ACK transmission is to be delayed based on the downlink symbol overlap on a PUCCH cell slot on the PUCCH cell associated with the first cell slot N.

Description

Method for transmitting HARQ-ACK information, user equipment, processing device, storage medium, method for receiving HARQ-ACK information, and base station

Technical Field

The present disclosure relates to a wireless communication system.

Background

Various technologies such as machine-to-machine (M2M) communication, machine Type Communication (MTC), and various devices requiring high data throughput, for example, smart phones and tablet Personal Computers (PCs), have emerged and become popular. Thus, the data throughput required to be processed in cellular networks increases rapidly. To meet such a rapid increase in data throughput, a carrier aggregation technique or a cognitive radio technique for effectively employing more bands and a Multiple Input Multiple Output (MIMO) technique or a multiple Base Station (BS) cooperation technique for improving the data capacity transmitted on limited frequency resources have been developed.

As more and more communication devices require greater communication capacity, enhanced mobile broadband (eMBB) communication relative to conventional Radio Access Technologies (RATs) is required. In addition, large-scale machine type communication (mctc) for providing various services anytime and anywhere by connecting a plurality of devices and objects to each other is one of the main problems to be considered in next-generation communication.

Communication system designs that consider reliability and delay sensitive service/User Equipment (UE) are also being discussed. The introduction of next generation RATs is being discussed considering emmbb communication, mctc, ultra Reliable Low Latency Communication (URLLC), etc.

Disclosure of Invention

Technical problem

With the introduction of new radio communication technologies, the number of UEs to which a BS should provide services in a prescribed resource region is increasing, and the amount of data and control information transmitted/received by/from the BS to/from the UEs providing services is also increasing. Since the amount of resources available to the BS for communication with the UE is limited, a new method for the BS to efficiently receive/transmit uplink/downlink data and/or uplink/downlink control information using limited radio resources is required. In other words, due to the increase in the density of nodes and/or the density of UEs, a method of efficiently using high-density nodes or high-density UEs for communication is needed.

There is also a need for a method of efficiently supporting various services having different requirements in a wireless communication system.

For applications where performance is delay/delay sensitive, overcoming the delay or latency is an important challenge.

In addition, it is necessary to specify how the UE and the BS will operate when configuring Physical Uplink Control Channel (PUCCH) cell handover and hybrid automatic repeat request (HARQ) delay.

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

Technical proposal

In an aspect of the present disclosure, a method of transmitting hybrid automatic repeat request-acknowledgement (HARQ-ACK) information by a User Equipment (UE) in a wireless communication system is provided. The method may comprise the steps of: performing Physical Downlink Shared Channel (PDSCH) reception; determining a Physical Uplink Control Channel (PUCCH) cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In another aspect of the present disclosure, a UE configured to transmit HARQ-ACK information in a wireless communication system is provided. The UE may include: at least one transceiver; at least one processor; and at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations. The operations may include: PDSCH reception; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In another aspect of the present disclosure, a processing apparatus is provided. The processing device may include: at least one processor; and at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations. The operations may include: PDSCH reception; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In another aspect of the present disclosure, a computer-readable storage medium is provided. The computer-readable storage medium may be configured to store at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a UE. The operations may include: PDSCH reception; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In another aspect of the present disclosure, a computer program stored in a computer readable storage medium is provided. The computer program may include at least one program code including instructions that, when executed, cause at least one processor to perform operations. The operations may include: PDSCH reception; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In another aspect of the present disclosure, there is provided a method of receiving hybrid automatic repeat request-acknowledgement (HARQ-ACK) information from a User Equipment (UE) by a Base Station (BS) in a wireless communication system, the method comprising the steps of: performing PDSCH transmission; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK reception for PDSCH transmission and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which HARQ-ACK reception is delayed based on the HARQ-ACK reception overlapping with downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In another aspect of the present disclosure, a Base Station (BS) configured to receive HARQ-ACK information in a wireless communication system is provided. The BS may include: at least one transceiver; at least one processor; and at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations. The operations may include: performing PDSCH transmission; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK reception for PDSCH transmission and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which HARQ-ACK reception is delayed based on the HARQ-ACK reception overlapping with downlink symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In various aspects of the disclosure, the first cell time slot n may be a time slot in which HARQ-ACK transmission for PDSCH is scheduled.

In various aspects of the disclosure, multiple cells may be configured for PUCCH cell handover. Determining a PUCCH cell among the plurality of cells includes determining a PUCCH cell for the first cell slot n among the plurality of cells based on a predetermined rule for PUCCH cell handover.

In various aspects of the present disclosure, the target slot may be an earliest slot capable of performing HARQ-ACK reception among PUCCH cell slots determined based on a predetermined rule and a first cell slot on the first cell.

In various aspects of the present disclosure, HARQ-ACK transmission/reception may be performed in a PUCCH cell slot on a PUCCH cell for a first cell slot n based on HARQ-ACK transmission not overlapping with downlink symbols in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

This may be the earliest time slot that can be performed.

In various aspects of the disclosure, determining the target time slot may include: determining a PUCCH cell for a first cell slot n+k on the first cell based on a predetermined rule, where k is a positive integer; determining a PUCCH cell for a first cell slot n+k+1 on the first cell based on the HARQ-ACK reception overlapping with a downlink symbol in a PUCCH cell slot related to the first cell slot n+k among slots on the PUCCH cell for the first cell slot n+k; and determining whether HARQ-ACK transmission/reception can be performed in a PUCCH slot related to the first cell slot n+k+1 on a PUCCH cell for the first cell slot n+k+1.

In various aspects of the disclosure, PDSCH reception may be semi-persistently scheduled PDSCH reception.

The above-described solutions are only a part of examples of the present disclosure, and various examples into which technical features of the present disclosure are incorporated may be derived and understood by those skilled in the art from the following detailed description.

Advantageous effects

According to some implementations of the present disclosure, wireless communication signals may be efficiently transmitted/received. Thus, the overall throughput of the wireless communication system may be improved.

According to some implementations of the present disclosure, various services having different requirements may be efficiently supported in a wireless communication system.

According to some implementations of the present disclosure, the delay/delay generated during radio communication between communication devices may be reduced.

According to some implementations of the disclosure, when a User Equipment (UE) is able to switch cells to transmit PUCCH each time PUCCH is transmitted and delay transmission for hybrid automatic repeat request-acknowledgement (HARQ-ACK) for a semi-persistent scheduling (SPS) Physical Downlink Shared Channel (PDSCH) according to a Time Division Duplex (TDD) configuration, the UE may achieve lower delay of HARQ operation by combining Physical Uplink Control Channel (PUCCH) cell switching and HARQ-ACK delay.

Effects according to the present disclosure are not limited to those specifically described above, and other effects not described herein will be more clearly understood by those skilled in the art to which the present disclosure pertains from the following detailed description.

Drawings

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

fig. 1 shows an example of a communication system 1 to which an implementation of the present disclosure is applied;

fig. 2 is a block diagram illustrating an example of a communication device capable of performing a method according to the present disclosure;

fig. 3 illustrates another example of a wireless device capable of performing an implementation of the present disclosure;

fig. 4 shows an example of a frame structure used in a 3 rd generation partnership project (3 GPP) based wireless communication system;

fig. 5 shows a resource grid of time slots;

fig. 6 shows a slot structure used in a 3GPP based system;

fig. 7 illustrates an example of Physical Downlink Shared Channel (PDSCH) Time Domain Resource Assignment (TDRA) caused by a Physical Downlink Control Channel (PDCCH) and an example of Physical Uplink Shared Channel (PUSCH) TDRA caused by the PDCCH;

fig. 8 illustrates a hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission/reception process;

Fig. 9 shows an example of multiplexing Uplink Control Information (UCI) with PUSCH;

fig. 10 illustrates an example of a process of a UE having overlapping Physical Uplink Control Channels (PUCCHs) in a single slot to handle a collision between UL channels;

fig. 11 illustrates a case of performing UCI multiplexing based on fig. 10;

fig. 12 shows a process of a UE having overlapping PUCCHs and PUSCHs in a single slot to handle collision between UL channels;

fig. 13 illustrates UCI multiplexing considering a timeline condition;

fig. 14 shows an exemplary HARQ-ACK delay;

fig. 15 illustrates an exemplary PUCCH cell handover;

fig. 16 illustrates a HARQ-ACK transmission flow in accordance with some implementations of the present disclosure;

fig. 17 illustrates cells and time slots transmitting HARQ-ACK responses according to some implementations of the present disclosure; and

fig. 18 illustrates a HARQ-ACK reception flow in accordance with some implementations of the present disclosure.

Detailed Description

Hereinafter, an implementation according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below with reference to the appended drawings is intended to illustrate exemplary implementations of the present disclosure and is not intended to show the only implementations that can be implemented according to the present disclosure. The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one skilled in the art that the present disclosure may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or may be shown in block diagram form, focusing on important features of the structures and devices, so as not to obscure the concepts of the present disclosure. The same reference numbers will be used throughout this disclosure to refer to the same or like parts.

The techniques, apparatuses and systems described below may be applied to various wireless multiple access systems. For example, multiple-access systems may include Code Division Multiple Access (CDMA) systems, frequency Division Multiple Access (FDMA) systems, time Division Multiple Access (TDMA) systems, orthogonal Frequency Division Multiple Access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, multiple carrier frequency division multiple access (MC-FDMA) systems, and so forth. CDMA may be implemented by a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA 2000. TDMA may be implemented by radio technologies such as global system for mobile communications (GSM), general Packet Radio Service (GPRS), enhanced data rates for GSM evolution (EDGE) (i.e., GERAN), and the like. OFDMA may be embodied by radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA (E-UTRA), and the like. UTRA is part of Universal Mobile Telecommunications System (UMTS), and 3 rd generation partnership project (3 GPP) Long Term Evolution (LTE) is part of E-UMTS using E-UTRA. 3GPP LTE employs OFDMA on the Downlink (DL) and SC-FDMA on the Uplink (UL). LTE-advanced (LTE-a) is an evolved version of 3GPP LTE.

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

For terms and techniques not described in detail among terms and techniques used in the present disclosure, reference may be made to 3 GPP-based standard specifications (e.g., 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, 3GPP TS 36.300, 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.214, 3GPP TS 38.300, 3GPP TS 38.321, 3GPP TS 38.331, etc.).

In examples of the present disclosure described later, if a device "assumes" something, this may mean that the channel transmitting entity transmits the channel in compliance with the corresponding "assumption". This may also mean that the channel receiving entity receives or decodes the channel in a form conforming to the "hypothesis" in compliance with the "hypothesis" transmitting the channel.

In the present disclosure, a User Equipment (UE) may be fixed or mobile. Each of the various apparatuses that transmit and/or receive user data and/or control information through communication with a Base Station (BS) may be a UE. The term UE may be referred to as a terminal device, mobile Station (MS), mobile Terminal (MT), user Terminal (UT), subscriber Station (SS), wireless device, personal Digital Assistant (PDA), wireless modem, handheld device, etc. In the present disclosure, a BS refers to a fixed station that communicates with a UE and/or another BS and exchanges data and control information with the UE and the other BS. The term BS may be referred to as an Advanced Base Station (ABS), a Node B (NB), an evolved node B (eNB), a Base Transceiver System (BTS), an Access Point (AP), a Processing Server (PS), etc. Specifically, the BS of the Universal Terrestrial Radio Access (UTRAN) is referred to as NB, the BS of the evolved UTRAN (E-UTRAN) is referred to as eNB, and the BS of the new radio access technology network is referred to as gNB. Hereinafter, for convenience of description, regardless of the type or version of the communication technology, NB, eNB or gNB will be referred to as BS.

In the present disclosure, a node refers to a fixed point capable of transmitting/receiving radio signals to/from a UE by communicating with the UE. Regardless of its name, various types of BSs may act as nodes. For example, BS, NB, eNB, a pico cell eNB (PeNB), a home eNB (HeNB), a relay, a repeater, etc. may be a node. In addition, the node may not be a BS. For example, a Radio Remote Head (RRH) or a Radio Remote Unit (RRU) may be a node. Typically, the RRHs and RRUs have a lower power level than the BS. Since the RRH or RRU (hereinafter, RRH/RRU) is generally connected to the BS through a dedicated line such as an optical cable, the cooperative communication according to the RRH/RRU and the BS can be smoothly performed as compared with the cooperative communication according to the BS connected through a wireless link. At least one antenna is mounted per node. Antennas may refer to physical antenna ports or to virtual antennas or groups of antennas. Nodes may also be referred to as points.

In this disclosure, a cell refers to a particular geographic area in which one or more nodes provide communication services. Thus, in the present disclosure, communication with a particular cell may mean communication with a BS or node that provides communication services to the particular cell. The DL/UL signal of a specific cell refers to DL/UL signals from/to a BS or node providing communication service for the specific cell. The cell providing UL/DL communication services to the UE is specifically referred to as a serving cell. In addition, the channel state/quality of a specific cell refers to the channel state/quality of a channel or communication link generated between a BS or node providing a communication service to the specific cell and a UE. In a 3 GPP-based communication system, a UE may measure DL channel state from a particular node using cell-specific reference signal (CRS) transmitted on CRS resources and/or channel state information reference signal (CSI-RS) transmitted on CSI-RS resources allocated to the particular node by an antenna port of the particular node.

The 3 GPP-based communication system uses the concept of cells in order to manage radio resources and to distinguish cells related to radio resources from cells of a geographical area.

A "cell" of a geographical area may be understood as a coverage area where a node may use a carrier to provide a service, and a "cell" of radio resources is associated with a Bandwidth (BW) which is a frequency range configured by the carrier. Since DL coverage (the range over which a node can transmit a valid signal) and UL coverage (the range over which a node can receive a valid signal from a UE) depend on the carrier on which the signal is carried, the coverage of a node can also be associated with the coverage of a "cell" of the radio resource used by that node. Thus, the term "cell" may be used to indicate sometimes the service coverage of a node, to indicate radio resources at other times, or to indicate at other times the range reached by a signal using radio resources with an effective strength.

In the 3GPP communication standard, the concept of cells is used in order to manage radio resources. A "cell" associated with radio resources is defined by a combination of DL resources and UL resources, i.e., a combination of DL Component Carriers (CCs) and UL CCs. A cell may be configured by DL resources only or by a combination of DL and UL resources. If carrier aggregation is supported, a link between a carrier frequency of a DL resource (or DL CC) and a carrier frequency of a UL resource (or UL CC) may be indicated by system information. For example, the combination of DL resources and UL resources may be indicated by a system information block type 2 (SIB 2) linkage. In this case, the carrier frequency may be equal to or different from the center frequency of each cell or CC. When Carrier Aggregation (CA) is configured, the UE has only one Radio Resource Control (RRC) connection with the network. During RRC connection setup/re-establishment/handover, one serving cell provides non-access stratum (NAS) mobility information. During RRC connection re-establishment/handover, one serving cell provides security input. This cell is called a primary cell (Pcell). A Pcell refers to a cell operating on a primary frequency where a UE performs an initial connection establishment procedure or initiates a connection re-establishment procedure. Depending on the UE capability, the secondary cell (Scell) may be configured to form a set of serving cells with the Pcell. Scell may be configured after RRC connection establishment is complete and used to provide additional radio resources in addition to resources of a specific cell (SpCell). The carrier corresponding to the Pcell on DL is called a downlink primary CC (DL PCC), and the carrier corresponding to the Pcell on UL is called an uplink primary CC (UL PCC). The carrier corresponding to Scell on DL is referred to as downlink secondary CC (DL SCC), and the carrier corresponding to Scell on UL is referred to as uplink secondary CC (UL SCC).

In Dual Connectivity (DC) operation, the term special cell (SpCell) refers to a Pcell of a primary cell group (MCG) or a primary secondary cell (Pcell) of a Secondary Cell Group (SCG). SpCell supports PUCCH transmission and contention-based random access and is always enabled. The MCG is a set of serving cells associated with a master node (e.g., BS) and includes a SpCell (Pcell) and optionally one or more scells. For a UE configured with DC, the SCG is a subset of serving cells associated with the secondary node and includes PSCell and 0 or more scells. PSCell is the primary Scell of SCG. For UEs in rrc_connected state that are not configured with CA or DC, there is only one serving cell including only Pcell. For a UE in rrc_connected state, configured with CA or DC, the term serving cell refers to the set of cells including SpCell and all scells. In DC, two Medium Access Control (MAC) entities are configured for the UE, i.e., one MAC entity for the MCG and one MAC entity for the SCG.

For a UE configured with CA and not configured with DC, a Pcell PUCCH group (also referred to as a primary PUCCH group) including Pcell and 0 or more scells and a Scell PUCCH group (also referred to as a secondary PUCCH group) including only scells may be configured. For Scell, scell transmitting PUCCH associated with a corresponding cell (hereinafter, PUCCH cell) may be configured. The Scell indicating the PUCCH Scell belongs to the Scell PUCCH group (i.e., the secondary PUCCH group) and PUCCH transmission of related Uplink Control Information (UCI) is performed on the PUCCH Scell. If no PUCCH Scell is indicated for Scell or the cell indicated for PUCCH transmission of Scell is Pcell, scell belongs to Pcell PUCCH group (i.e. primary PUCCH group) and PUCCH transmission of related UCI is performed on Pcell. Hereinafter, if the UE is configured with an SCG and some implementations of the present disclosure related to PUCCH are applied to the SCG, the primary cell may refer to a PSCell of the SCG. If the UE is configured with a PUCCH Scell and some implementations of the present disclosure related to PUCCH are applied to the secondary PUCCH group, the primary cell may refer to the PUCCH Scell of the secondary PUCCH group.

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

The 3 GPP-based communication standard defines DL physical channels corresponding to resource elements carrying information originating from higher layers and DL physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, a Physical Downlink Shared Channel (PDSCH), a Physical Broadcast Channel (PBCH), a Physical Multicast Channel (PMCH), a Physical Control Format Indicator Channel (PCFICH), a Physical Downlink Control Channel (PDCCH), and the like are defined as DL physical channels, and a Reference Signal (RS) and a Synchronization Signal (SS) are defined as DL physical signals. The RS (also called pilot) represents a signal with a predefined special waveform known to both BS and UE. For example, demodulation reference signals (DMRS), channel state information RS (CSI-RS), and the like are defined as DL RS. The 3 GPP-based communication standard defines UL physical channels corresponding to resource elements carrying information originating from higher layers and UL physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), and a Physical Random Access Channel (PRACH) are defined as UL physical channels, and DMRS for UL control/data signals, sounding Reference Signals (SRS) for UL channel measurement, and the like are defined.

In this disclosure, PDCCH refers to a set of time-frequency resources (e.g., resource Elements (REs)) that carry Downlink Control Information (DCI), and PDSCH refers to a set of time-frequency resources that carry DL data. PUCCH, PUSCH and PRACH refer to a set of time-frequency resources carrying UCI, a set of time-frequency resources carrying UL data, and a set of time-frequency resources carrying a random access signal, respectively. In the following description, "UE transmits/receives PUCCH/PUSCH/PRACH" is used as the same meaning as UE transmits/receives UCI/UL data/random access signal on or through PUCCH/PUSCH/PRACH, respectively. In addition, "BS transmits/receives PBCH/PDCCH/PDSCH" is used as the same meaning as BS transmits broadcast information/DCI/DL data on or through PBCH/PDCCH/PDSCH, respectively.

In this specification, radio resources (e.g., time-frequency resources) scheduled or configured by a BS for a UE to transmit or receive PUCCH/PUSCH/PDSCH may be referred to as PUCCH/PUSCH/PDSCH resources.

Since the communication device receives a Synchronization Signal Block (SSB), DMRS, CSI-RS, PBCH, PDCCH, PDSCH, PUSCH, and/or PUCCH in the form of a radio signal on a cell, the communication device may not select and receive a radio signal including only a specific physical channel or a specific physical signal through a Radio Frequency (RF) receiver or may not select and receive a radio signal without a specific physical channel or a specific physical signal through an RF receiver. In practice, the communication device receives radio signals on a cell via an RF receiver, converts the radio signals as RF band signals to baseband signals, and then decodes physical signals and/or physical channels in the baseband signals using one or more processors. Thus, in some implementations of the present disclosure, not receiving a physical signal and/or physical channel may mean that the communication device is not attempting to recover the physical signal and/or physical channel from the radio signal, e.g., is not attempting to decode the physical signal and/or physical channel, but the non-communication device is not actually receiving the radio signal including the corresponding physical signal and/or physical channel.

As more and more communication devices require greater communication capacity, eMBB communication with respect to the conventional Radio Access Technology (RAT) is required. In addition, large-scale MTC, which provides various services anytime and anywhere by connecting a plurality of devices and objects to each other, is one of the main problems to be considered in next-generation communication. In addition, communication system designs that consider reliability and delay sensitive services/UEs are also being discussed. Considering eMBB communication, large-scale MTC, ultra-reliable low latency communication (URLLC), etc., the introduction of next generation RATs is being discussed. Currently, in 3GPP, research on the next generation mobile communication system after EPC is underway. In the present disclosure, for convenience, the corresponding technology is referred to as a New RAT (NR) or a fifth generation (5G) RAT, and a system using NR or supporting NR is referred to as an NR system.

Fig. 1 shows an example of a communication system 1 to which an implementation of the present disclosure is applied. Referring to fig. 1, a communication system 1 applied to the present disclosure includes a wireless device, a BS, and a network. Here, a wireless device means a device that performs communication using a RAT (e.g., 5G NR or LTE (e.g., E-UTRA)), and may be referred to as a communication/radio/5G device. Wireless devices may include, but are not limited to, robots 100a, vehicles 100b-1 and 100b-2, augmented reality (XR) devices 100c, handheld devices 100d, home appliances 100e, internet of things (IoT) devices 100f, and Artificial Intelligence (AI) devices/servers 400. For example, the vehicle may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing vehicle-to-vehicle communication. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., an unmanned aerial vehicle). XR devices may include Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) devices, and may be implemented in the form of head-mounted devices (HMDs), head-up displays (HUDs) installed in vehicles, televisions, smart phones, computers, wearable devices, home appliance devices, digital signage, vehicles, robots, and the like. The handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters. For example, the BS and network may also be implemented as wireless devices, and a particular wireless device may operate as a BS/network node with respect to another wireless device.

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

Wireless communication/connections 150a and 150b may be established between wireless devices 100 a-100 f and BS200, as well as between wireless devices 100 a-100 f. Here, wireless communications/connections such as UL/DL communications 150a and side link communications 150b (or device-to-device (D2D) communications) may be established over various RATs (e.g., 5G NR). The wireless device and BS/wireless device may transmit/receive radio signals to/from each other through wireless communication/connections 150a and 150b. To this end, at least a part of various configuration information configuration procedures for transmitting/receiving radio signals, various signal processing procedures (e.g., channel coding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocation procedures may be performed based on various proposals of the present disclosure.

Fig. 2 is a block diagram illustrating an example of a communication device capable of performing a method according to the present disclosure. Referring to fig. 2, the first wireless device 100 and the second wireless device 200 may transmit and/or receive radio signals through various RATs (e.g., LTE and NR). Here, { first wireless device 100 and second wireless device 200} may correspond to { wireless device 100x and BS200} and/or { wireless device 100x and wireless device 100x } of fig. 1.

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

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

Wireless communication techniques implemented in wireless devices 100 and 200 of the present disclosure may include narrowband internet of things for low power communications, as well as LTE, NR, and 6G. For example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology and implemented in standards such as LTE Cat NB1 and/or LTE Cat NB 2. However, NB-IoT technology is not limited to the above names. Additionally or alternatively, wireless communication techniques implemented in wireless devices XXX and YYY of the present disclosure may perform communications based on LTE-M techniques. For example, LTE-M technology may be an example of LPWAN technology and is referred to by various names including enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented in at least one of the following various standards: 1) LTE CAT 0, 2) LTE CAT M1, 3) LTE CAT M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine-type communications, and/or 7) LTE M, etc., but the LTE-M technology is not limited to the above names. Additionally or alternatively, in view of low power communication, the wireless communication technology implemented in the wireless devices XXX and YYY of the present disclosure may include at least one of ZigBee, bluetooth, and LPWAN, but the wireless communication technology is not limited to the above names. For example, zigBee technology may create Personal Area Networks (PANs) related to small/low power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

Hereinafter, hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as a Physical (PHY) layer, a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Resource Control (RRC) layer, and a Service Data Adaptation Protocol (SDAP) layer). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the functions, procedures, proposals, and/or methods disclosed in the present disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information in accordance with the functions, processes, proposals, and/or methods disclosed in the present disclosure. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, proposals, and/or methods disclosed in the present disclosure, and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, proposals, and/or methods disclosed in the present disclosure.

One or more of the processors 102 and 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more of the processors 102 and 202 may be implemented in hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors 102 and 202. The functions, processes, proposals and/or methods disclosed in the present disclosure may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes or functions. Firmware or software configured to perform the functions, processes, proposals and/or methods disclosed in the present disclosure may be included in the one or more processors 102 and 202 or stored in the one or more memories 104 and 204 to be driven by the one or more processors 102 and 202. The functions, procedures, proposals and/or methods disclosed in the present disclosure may be implemented in the form of codes, commands and/or command sets using firmware or software.

One or more memories 104 and 204 may be coupled to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, commands, and/or instructions. One or more of the memories 104 and 204 may be configured by read-only memory (ROM), random-access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, a hard drive, registers, a cache memory, a computer-readable storage medium, and/or combinations thereof. The one or more memories 104 and 204 may be located internal and/or external to the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 by various techniques, such as a wired or wireless connection.

One or more transceivers 106 and 206 may transmit the user data, control information, and/or radio signals/channels referred to in the methods and/or operational flow diagrams of the present disclosure to one or more other devices. One or more transceivers 106 and 206 may receive the user data, control information, and/or radio signals/channels mentioned in the functions, processes, proposals, methods, and/or operational flowcharts disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control such that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control such that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208. The one or more transceivers 106 and 206 may be configured to transmit and receive the user data, control information, and/or radio signals/channels referred to in the functions, processes, proposals, methods, and/or operational flowcharts disclosed in the present disclosure through the one or more antennas 108 and 208. In the present disclosure, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106 and 206 may convert received radio signals/channels, etc., from RF band signals to baseband signals for processing received user data, control information, radio signals/channels, etc., using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert user data, control information, radio signals/channels, etc., processed using the one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more of the transceivers 106 and 206 may include (analog) oscillators and/or filters.

Fig. 3 illustrates another example of a wireless device capable of performing implementations of the present disclosure. Referring to fig. 3, wireless devices 100 and 200 may correspond to wireless devices 100 and 200 of fig. 2 and may be configured by various elements, components, units/portions, and/or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and an additional component 140. The communication unit may include a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 may include one or more processors 102 and 202 and/or one or more memories 104 and 204 of fig. 2. For example, transceiver 114 may include one or more transceivers 106 and 206 and/or one or more antennas 108 and 208 of fig. 2. The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140, and controls the overall operation of the wireless device. For example, the control unit 120 may control the electrical/mechanical operation of the wireless device based on programs/codes/commands/information stored in the memory unit 130. The control unit 120 may transmit information stored in the memory unit 130 to the outside (e.g., other communication devices) via the communication unit 110 through a wireless/wired interface, or store information received from the outside (e.g., other communication devices) via the communication unit 110 in the memory unit 130 through a wireless/wired interface.

The additional components 140 may be configured differently depending on the type of wireless device. For example, the additional component 140 may include at least one of a power supply unit/battery, an input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented as, but is not limited to, a robot (100 a of fig. 1), a vehicle (100 b-1 and 100b-2 of fig. 1), an XR device (100 c of fig. 1), a handheld device (100 d of fig. 1), a home appliance (100 e of fig. 1), an IoT device (100 f of fig. 1), a digital broadcast UE, a holographic device, a public safety device, an MTC device, a medical device, a financial technology device (or a financial device), a security device, a climate/environment device, an AI server/device (400 of fig. 1), a BS (200 of fig. 1), a network node, and the like. Wireless devices may be used in mobile or stationary locations depending on the use/service.

In fig. 3, the various elements, components, units/portions and/or modules in wireless devices 100 and 200 may all be connected to each other through wired interfaces, or at least a portion thereof may be connected wirelessly through communication unit 110. For example, in each of the wireless devices 100 and 200, the control unit 120 and the communication unit 110 may be connected by wire, and the control unit 120 and the first unit (e.g., 130 and 140) may be connected wirelessly through the communication unit 110. The various elements, components, units/portions and/or modules within wireless devices 100 and 200 may also include one or more elements. For example, the control unit 120 may be configured by a set of one or more processors. As an example, the control unit 120 may be configured by a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing unit, and a memory control processor. As another example, the memory 130 may be configured by Random Access Memory (RAM), dynamic RAM (DRAM), read Only Memory (ROM)), flash memory, volatile memory, non-volatile memory, and/or combinations thereof.

In the present disclosure, at least one memory (e.g., 104 or 204) may store instructions or programs that, when executed, may cause at least one processor operatively connected to the at least one memory to perform operations in accordance with some embodiments or implementations of the present disclosure.

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

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

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

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

Fig. 4 shows an example of a frame structure used in a 3 GPP-based wireless communication system.

The frame structure of fig. 4 is merely exemplary, and the number of subframes, the number of slots, and the number of symbols in a frame may be variously changed. In an NR system, different sets of OFDM parameters (e.g., subcarrier spacing (SCS)) may be configured for multiple cells aggregated for one UE. Thus, the (absolute time) duration of a time resource comprising the same number of symbols, e.g. subframes, slots or Transmission Time Intervals (TTIs), may be configured differently for the aggregated cells. Here, the symbols may include OFDM symbols (or cyclic prefix-OFDM (CP-OFDM) symbols) and SC-FDMA symbols (or discrete fourier transform-spread-OFDM (DFT-s-OFDM) symbols). In this disclosure, symbols, OFDM-based symbols, OFDM symbols, CP-OFDM symbols, and DFT-s-OFDM symbols are used interchangeably.

Referring to fig. 4, in the NR system, UL transmission and DL transmission are organized into frames. Each frame has T _f ＝(△f _max *N _f /100)*T _c Time duration=10 ms and is divided into two half frames of 5ms each. The basic unit of time for NR is T _c ＝1/(△f _max *N _f ) Wherein Δf _max ＝480*10 ³ Hz and N _f =4096. For reference, the basic time unit of LTE is T _s ＝1/(△f _ref *N _f,ref ) Wherein Δf _ref ＝15*10 ³ Hz and N _f,ref ＝2048。T _c And T _f With a constant k=t _c /T _f A relation of=64. Each half frame includes 5 subframes, and the duration T of a single subframe _sf 1ms. The subframe is further divided into slots, and the number of slots in the subframe depends on the subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix. In the normal CP, each slot includes 14 OFDM symbols, and in the extended CP, each slot includes 12 OFDM symbols. The parameter set depends on the exponentially scalable subcarrier spacing Δf=2 ^u *15kHz. The following table shows the number of OFDM symbols per slot (N ^slot _symb ) Number of slots per frame (N ^frame,u _slot ) And the number of slots per subframe (N ^subframe,u _slot )。

TABLE 1

u	N ^slot _symb	N ^frame,u _slot	N ^subframe,u _slot
				0	14	10	1
1	14	20	2
				2	14	40	4
3	14	80	8
				4	14	160	16

The following table shows the subcarrier spacing Δf=2 ^u *15kHz, the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe.

TABLE 2

u	N ^slot _symb	N ^frame,u _slot	N ^subframe,u _slot
				2	12	40	4

For subcarrier spacing configuration u, the slots may be indexed in ascending order within a subframe as follows: n is n ^u _s ∈{0,...,n ^subframe ^,u _slot -1}, and indexed in ascending order within the frame as follows: n is n ^u _s,f ∈{0,...,n ^frame,u _slot -1}。

Fig. 5 shows a resource grid of time slots. A slot includes a plurality of (e.g., 14 or 12) symbols in the time domain. For each parameter set (e.g., subcarrier spacing) and carrier, from a Common Resource Block (CRB) N indicated by higher layer signaling (e.g., RRC signaling) ^start,u _grid Start defining N ^size,u _grid,x *N ^RB _sc Sub-carriers and N ^subframe,u _symb Resource grid of OFDM symbols, where N ^size,u _grid,x Is the number of Resource Blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink. N (N) ^RB _sc Is the number of subcarriers per RB. In a 3GPP based wireless communication system, N ^RB _sc Typically 12. For a given antenna port p, subcarrier spacing configuration u and transmission link (DL or UL), there is one resource grid. The carrier bandwidth N of the subcarrier spacing configuration u is given to the UE by higher layer parameters (e.g., RRC parameters) ^size,u _grid . Each element in the resource grid for the antenna port p and the subcarrier spacing configuration u is referred to as a Resource Element (RE), and one complex symbol may be mapped to each RE. Each RE in the resource grid is uniquely marked by an index k in the frequency domain and an index l representing the symbol position relative to a reference point in the time domainAnd (5) identifying. In the NR system, RBs are defined by 12 consecutive subcarriers in the frequency domain. In the NR system, RBs are classified into CRBs and Physical Resource Blocks (PRBs). For subcarrier spacing configuration u, the CRB is numbered from 0 upward in the frequency domain. The center of subcarrier 0 of CRB 0 of subcarrier spacing configuration u is equal to "point a" serving as a common reference point of the RB grid. PRBs for subcarrier spacing configuration u are defined in a bandwidth part (BWP) and range from 0 to N ^size,u _BWP,i -1 number, where i is the number of BWP. PRB n in BWP i _PRB And CRB n ^u _CRB The relation between is represented by n ^u _PRB ＝n ^u _CRB +N ^size,u _BWP,i Given, where N ^size _BWP,i Is the CRB where BWP starts with respect to CRB 0. BWP comprises a plurality of consecutive RBs in the frequency domain. For example, BWP may be a given parameter set u in BWP i on a given carrier _i A subset of defined contiguous CRBs. The carrier may include a maximum of N (e.g., 5) BWPs. The UE may be configured with one or more BWPs on a given component carrier. Data communication is performed through the enabled BWP, and only a predetermined number of BWP (e.g., one BWP) among the BWP configured for the UE on the component carrier may be active.

For each serving cell in the set of DL BWP or UL BWP, the network may configure at least the initial DL BWP and one (if the serving cell is configured with an uplink) or two (if a supplemental uplink is used) initial UL BWP. The network may configure additional UL and DL BWP. For each DL BWP or UL BWP, the following parameters may be provided to the UE for the serving cell: i) SCS (SCS); ii) CP; iii) From at N ^start _BWP Supposition of =275 indicates offset RB _set And length L _RB CRB N provided as RRC parameter locationBandWidth of Resource Indicator Value (RIV) ^start _BWP ＝O _carrier +RB _start And the number N of contiguous RBs ^size _BWP ＝L _RB And a value O provided by RRC parameter offsettopcarrier for SCS _carrier The method comprises the steps of carrying out a first treatment on the surface of the Index in the set of DL BWP or UL BWP; a set of BWP common parameters; and a set of BWP-specific parameters.

Virtual Resource Blocks (VRBs) may be defined within BWP andfrom 0 to N ^size,u _BWP,i -1 index, wherein i denotes BWP number. VRBs may be mapped to PRBs according to a non-interleaved mapping. In some implementations, for non-interleaved VRB-to-PRB mapping, VRB n may be mapped to PRB n.

A UE configured with carrier aggregation may be configured to use one or more cells. If the UE is configured with multiple serving cells, the UE may be configured with one or more cell groups. The UE may also be configured with multiple cell groups associated with different BSs. Alternatively, the UE may be configured with multiple cell groups associated with a single BS. Each cell group of the UE includes one or more serving cells and includes a single PUCCH cell configuring PUCCH resources. The PUCCH cell may be Scell configured as a PUCCH cell among Pcell of a corresponding cell group or Scell. Each serving cell of the UE belongs to one of the cell groups of the UE and does not belong to multiple cells.

Fig. 6 shows a slot structure used in a 3GPP based system. In all 3GPP based systems (e.g. in NR systems), each slot may have a self-contained structure comprising i) DL control channels, ii) DL or UL data and/or iii) UL control channels. For example, the first N symbols in a slot may be used to transmit DL control channels (hereinafter DL control region), and the last M symbols in a slot may be used to transmit UL control channels (hereinafter UL control region), where N and M are integers other than negative numbers. A resource region (hereinafter, a data region) between the DL control region and the UL control region may be used to transmit DL data or UL data. Symbols in a single slot may be divided into consecutive symbol groups that may be used as DL symbols, UL symbols, or flexible symbols. Hereinafter, information indicating how each symbol in a slot is used will be referred to as a slot format. For example, the slot format may define which symbols in the slot are for UL and which symbols in the slot are for DL.

When the BS intends to operate a serving cell in a Time Division Duplex (TDD) mode, the BS may configure UL and DL allocation patterns for the serving cell through higher layer (e.g., RRC) signaling. For example, the following parameters may be used to configure a TDD DL-UL pattern:

-DL-UL-TransmissionPeriodicity providing periodicity of DL-UL pattern;

nrofDownlinkSlots, which provide the number of consecutive full DL slots at the beginning of each DL-UL pattern, where full DL slots are slots with DL symbols only;

nrofDownlinkSymbols, which provide the number of consecutive DL symbols at the beginning of the slot immediately after the last full DL slot;

nrofUplinkSlots, which provides the number of consecutive full UL slots at the end of each DL-UL pattern, where a full UL slot is a slot with UL symbols only; and

nrofUplinkSymbols, which provide the number of consecutive UL symbols at the end of the slot immediately preceding the first full UL slot.

The remaining symbols, which are not configured as DL symbols or UL symbols, among the symbols in the DL-UL pattern are flexible symbols.

If the configuration of the TDD DL-UL pattern, i.e., TDD UL-DL configuration (e.g., TDD-UL-DL-configuration command or TDD-UL-DL-configuration defined) is provided to the UE through higher layer signaling, the UE sets a slot format per slot on a plurality of slots based on the configuration.

For the symbols, although various combinations of DL symbols, UL symbols, and flexible symbols may exist, a predetermined number of combinations may be predefined as slot formats, and the predefined slot formats may be respectively identified by slot format indexes. The following table shows a part of the predefined slot format. In the following table, D represents DL symbols, U represents UL symbols, and F represents flexible symbols.

TABLE 3

To indicate which slot format is used in a specific slot among the predefined slot formats, the BS may configure a set of slot format combinations suitable for the corresponding serving cell per cell for the serving cell set through higher layer (e.g., RRC) signaling, and cause the UE to monitor a group common PDCCH of a Slot Format Indicator (SFI) through higher layer (e.g., RRC) signaling. Hereinafter, DCI carried by a group common PDCCH of an SFI will be referred to as an SFIDCI. DCI format 2_0 is used as SFIDCI. For example, for each serving cell in the set of serving cells, the BS may provide to the UE a (start) position of a slot format combination ID (i.e., SFI index) of the corresponding serving cell in the SFIDCI, a set of slot format combinations applicable to the serving cell, and a reference subcarrier spacing configuration for each of the slot formats in the slot format combinations indicated by the SFI index value in the SFIDCI. One or more slot formats are configured for each slot format combination in the set of slot format combinations and a slot format combination ID (i.e., SFI index) is assigned to the slot format combination. For example, when the BS intends to configure a slot format combination having N slot formats, N slot format indexes among slot format indexes of a predefined slot format (see, e.g., table 3) may be indicated for the slot format combination. To configure a group common PDCCH in which a UE monitors an SFI, a BS informs the UE of an SFI-RNTI corresponding to a Radio Network Temporary Identifier (RNTI) for the SFI and a total length of a DCI payload scrambled with the SFI-RNTI. Upon detecting the PDCCH based on the SFI-RNTI, the UE may determine a slot format of a corresponding serving cell from an SFI index of the serving cell among SFI indexes in a DCI payload in the PDCCH.

The symbols indicated as flexible symbols by the TDD DL-UL pattern configuration may be indicated as UL symbols, DL symbols, or flexible symbols by SFIDCI. Symbols indicated as DL/UL symbols by TDD DL-UL pattern configuration are not overwritten by SFIDCI as UL/DL symbols or flexible symbols.

If the TDD DL-UL pattern is not configured, the UE determines whether each slot is for UL or DL based on SFIDCI and/or DCI (e.g., DCI Format 1_0, DCI Format 1_1, DCI Format 1_2, DCI Format 0_0, DCI Format 0_1, DCI Format 0_2, and DCI Format 2_3) for scheduling or triggering transmission of a DL or UL signal and determines symbol allocation in each slot.

The NR frequency band is defined as two types of frequency ranges, FR1 and FR2.FR2 is also known as millimeter wave (mmW). The following table shows the frequency range over which NR can operate.

TABLE 4

Frequency range assignment	Corresponding frequency range	Subcarrier spacing
			FR1	410MHz-7125MHz	15、30、60kHz
FR2	24250MHz-52600MHz	60、120、240kHz

Hereinafter, physical channels usable in the 3 GPP-based wireless communication system will be described in detail.

The PDCCH carries DCI. For example, the PDCCH (i.e., DCI) carries information on a transport format and resource allocation of a downlink shared channel (DL-SCH), information on resource allocation of an uplink shared channel (UL-SCH), paging information on a Paging Channel (PCH), system information on the DL-SCH, information on resource allocation of a control message (e.g., a Random Access Response (RAR) transmitted on a PDSCH) of a higher layer (hereinafter, higher layer) among protocol stacks of the UE/BS than a physical layer, transmission power control command, information on activation/deactivation of a Configuration Scheduling (CS), and the like. The DCI including resource allocation information on the DL-SCH is referred to as PDSCH scheduling DCI, and the DCI including resource allocation information on the UL-SCH is referred to as PUSCH scheduling DCI. The DCI includes a Cyclic Redundancy Check (CRC). The CRC is masked/scrambled with various identifiers, e.g., a Radio Network Temporary Identifier (RNTI), according to the owner and purpose of the PDCCH. For example, if the PDCCH is for a particular UE, the CRS is masked with a UE identifier (e.g., cell-RNTI (C-RNTI)). If the PDCCH is used for a paging message, the CRC is masked with a paging RNTI (P-RNTI). If the PDCCH is used for system information (e.g., a System Information Block (SIB)), the CRC is masked with a system information RNTI (SI-RNTI). If the PDCCH is used for a random access response, the CRC is masked with a random access-RNTI (RA-RNTI).

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

PDSCH is a physical layer UL channel for UL data transmission. PDSCH carries DL data (e.g., DL-SCH transport blocks) and is subject to modulation such as Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64QAM, 256QAM, etc. The codeword is generated by encoding a Transport Block (TB). PDSCH may carry a maximum of two codewords. Scrambling and modulation mapping per codeword may be performed and modulation symbols generated from the respective codewords may be mapped to one or more layers. The respective layers are mapped to radio resources together with DMRS and generated as OFDM symbol signals. Then, the OFDM symbol signal is transmitted through the corresponding antenna port.

The PUCCH is a physical layer UL channel for Uplink Control Information (UCI) transmission. The PUCCH carries UCI. The UCI type transmitted on the PUCCH includes hybrid automatic repeat request acknowledgement (HARQ-ACK) information, scheduling Request (SR), and Channel State Information (CSI). UCI bits include HARQ-ACK information bits (if present), SR information bits (if present), link Recovery Request (LRR) information bits (if present), and CSI bits (if present). In the present disclosure, the HARQ-ACK information bits correspond to HARQ-ACK codebooks. In particular, a bit sequence in which HARQ-ACK information bits are arranged according to a predetermined rule is called a HARQ-ACK codebook.

-a Scheduling Request (SR): information for requesting UL-SCH resources.

-hybrid automatic repeat request (HARQ) -Acknowledgement (ACK): response to DL data packets (e.g., codewords) on PDSCH. The HARQ-ACK indicates whether the communication device successfully received the DL data packet. In response to a single codeword, a 1-bit HARQ-ACK may be transmitted. In response to the two codewords, a 2-bit HARQ-ACK may be transmitted. The HARQ-ACK response includes a positive ACK (abbreviated ACK), a Negative ACK (NACK), discontinuous Transmission (DTX), or NACK/DTX. Here, the term HARQ-ACK may be used interchangeably with HARQ ACK/NACK, or a/N.

-Channel State Information (CSI): feedback information about DL channels. The CSI may include Channel Quality Information (CQI), a Rank Indicator (RI), a Precoding Matrix Indicator (PMI), a CSI-RS resource indicator (CRI), an SS/PBCH resource block indicator (SSBRI), and a layer indicator (L1). CSI can be classified into CSI part 1 and CSI part 2 according to UCI types included in CSI. For example, CRI, RI, and/or CQI of the first codeword may be included in CSI part 1, and LI, PMI, and/or CQI of the second codeword may be included in CSI part 2.

-Link Recovery Request (LRR)

In the present disclosure, PUCCH resources configured/indicated by the BS for/to the UE for HARQ-ACK, SR, and CSI transmission are referred to as HARQ-ACK PUCCH resources, SR PUCCH resources, and CSI PUCCH resources, respectively, for convenience.

The PUCCH format may be defined as follows according to UCI payload size and/or transmission length (e.g., the number of symbols included in the PUCCH resource). For PUCCH formats, reference may also be made to table 5.

(0) PUCCH format 0 (PF 0 or F0)

Supported UCI payload size: up to K bits (e.g., k=2)

-number of OFDM symbols constituting a single PUCCH: 1 to X symbols (e.g., x=2)

-a transmission structure: only UCI signals are included in PUCCH format 0 without DMRS. The UE transmits UCI status by selecting and transmitting one of a plurality of sequences. For example, the UE transmits a specific UCI to the BS by transmitting one of a plurality of sequences through PUCCH (PUCCH format 0). The UE transmits PUCCH (PUCCH format 0) in PUCCH resources for a corresponding SR configuration only when transmitting a positive SR.

The configuration of PUCCH format 0 includes the following parameters for the corresponding PUCCH resource: an index of the initial cyclic shift, a number of symbols for PUCCH transmission, and/or a first symbol for PUCCH transmission.

(1) PUCCH format 1 (PF 1 or F1)

Supported UCI payload size: up to K bits (e.g., k=2)

-number of OFDM symbols constituting a single PUCCH: y to Z symbols (e.g., y=4 and z=14)

-a transmission structure: DMRS and UCI are configured/mapped in TDM to different OFDM symbols. In other words, the DMRS is transmitted in a symbol in which a modulation symbol is not transmitted, and UCI is represented as a product between a specific sequence (e.g., orthogonal Cover Code (OCC)) and a modulation (e.g., QPSK) symbol. Code Division Multiplexing (CDM) is supported between multiple PUCCH resources (conforming to PUCCH format 1) (within the same RB) by applying Cyclic Shift (CS)/OCC to both UCI and DMRS. PUCCH format 1 carries UCI of at most 2 bits and spreads modulation symbols in the time domain by OCC (differently configured according to whether frequency hopping is performed).

The configuration of PUCCH format 1 includes the following parameters for the corresponding PUCCH resource: an index of an initial cyclic shift, a number of symbols for PUCCH transmission, a first symbol for PUCCH transmission, and/or an index of OCC.

(2) PUCCH format 2 (PF 2 or F2)

Supported UCI payload size: over K bits (e.g., k=2)

-number of OFDM symbols constituting a single PUCCH: 1 to X symbols (e.g., x=2)

-a transmission structure: DMRS and UCI are configured/mapped using Frequency Division Multiplexing (FDM) within the same symbol. The UE transmits UCI by applying IFFT to the encoded UCI bits without DFT. PUCCH format 2 carries UCI of a bit size larger than K bits, and the modulation symbols are subjected to FDM with DMRS for transmission. For example, DMRS is located in symbol indexes #1, #4, #7, and #10 within a given RB with a density of 1/3. A Pseudo Noise (PN) sequence is used for the DMRS sequence. Frequency hopping may be enabled for 2-symbol PUCCH format 2.

The configuration of PUCCH format 2 includes the following parameters for the corresponding PUCCH resource: the number of PRBs, the number of symbols used for PUCCH transmission, and/or the first symbol used for PUCCH transmission.

(3) PUCCH format 3 (PF 3 or F3)

Supported UCI payload size: over K bits (e.g., k=2)

-a transmission structure: DMRS and UCI are configured/mapped to different OFDM symbols in TDM. The UE transmits UCI by applying DFT to the encoded UCI bits. PUCCH format 3 does not support UE multiplexing for the same time-frequency resource (e.g., the same PRB).

The configuration of PUCCH format 3 includes the following parameters for the corresponding PUCCH resource: the number of PRBs, the number of symbols used for PUCCH transmission, and/or the first symbol used for PUCCH transmission.

(4) PUCCH format 4 (PF 4 or F4)

Supported UCI payload size: over K bits (e.g., k=2)

-a transmission structure: DMRS and UCI are configured/mapped to different OFDM symbols in TDM. PUCCH format 4 may be multiplexed into up to 4 UEs in the same PRB by applying OCC at the front end of DFT and CS (or Interleaved FDM (IFDM) mapping) to DMRS. In other words, the modulation symbols of UCI undergo TDM with DMRS for transmission.

The configuration of PUCCH format 4 includes the following parameters for the corresponding PUCCH resource: the number of symbols for PUCCH transmission, the length of OCC, the index of OCC, and the first symbol for PUCCH transmission.

The following table shows PUCCH formats. The PUCCH formats can be divided into short PUCCH formats (formats 0 and 2) and long PUCCH formats (formats 1, 3, and 4) according to the PUCCH transmission length.

TABLE 5

PUCCH resources may be determined according to UCI type (e.g., a/N, SR or CSI). PUCCH resources for UCI transmission may be determined based on UCI (payload) size. For example, the BS may configure a plurality of PUCCH resource sets for the UE, and the UE may select a specific PUCCH resource set corresponding to a specific range according to a range (e.g., UCI bit number) of UCI (payload) size. For example, the UE may select one of the following PUCCH resource sets according to the UCI bit number NUCI.

PUCCH resource set #0 if UCI number of bits= <2

PUCCH resource set #1, if 2<UCI number of bits=<N ₁

...

PUCCH resource set # (K-1), if N _K-2 <UCI number of bits=<N _K-1

Here, K represents the number of PUCCH resource sets (K>1) And N _i The maximum UCI bit number supported by PUCCH resource set #i is represented. For example, PUCCH resource set #1 may include resources of PUCCH formats 0 to 1, and the other PUCCH resource sets may include resources of PUCCH formats 2 to 4 (see table 5).

The configuration of each PUCCH resource includes a PUCCH resource index, a starting PRB index, and a configuration of one of PUCCH formats 0 to 4. The BS configures a code rate for multiplexing HARQ-ACK, SR and CSI report within PUCCH transmission using PUCCH format 2, PUCCH format 3 or PUCCH format 4 to the UE through a higher layer parameter maxCodeRate. The higher layer parameter maxCodeRate is used to determine how to feedback UCI on PUCCH resources of PUCCH formats 2, 3 or 4.

If the UCI type is SR and CSI, PUCCH resources to be used for UCI transmission in the PUCCH resource set may be configured for the UE through higher layer signaling (e.g., RRC signaling). If the UCI type is HARQ-ACK of a semi-persistent scheduling (SPS) PDSCH, PUCCH resources in the PUCCH resource set to be used for UCI transmission may be configured for the UE through higher layer signaling (e.g., RRC signaling). On the other hand, if the UCI type is HARQ-ACK for PDSCH scheduled by DCI, PUCCH resources to be used for UCI transmission in the PUCCH resource set may be scheduled by DCI.

In the case of DCI-based PUCCH resource scheduling, the BS may transmit DCI to the UE on the PDCCH and indicate PUCCH resources to be used for UCI transmission in a specific PUCCH resource set through an ACK/NACK resource indicator (ARI) in the DCI. The ARI may be used to indicate PUCCH resources for ACK/NACK transmission and is also referred to as a PUCCH Resource Indicator (PRI). Here, DCI may be used for PDSCH scheduling and UCI may include HARQ-ACK for PDSCH. The BS may configure a PUCCH resource set including a greater number of PUCCH resources than the ARI can represent for the UE through (UE-specific) higher layer (e.g., RRC) signaling. The ARI may indicate PUCCH resource subsets of the PUCCH resource sets, and which PUCCH resource of the indicated PUCCH resource subsets to use may be determined according to an implicit rule based on transmission resource information (e.g. starting CCE index of PDCCH) on the PDCCH.

For UL-SCH data transmission, the UE should include UL resources available to the UE, and for DL-SCH data reception, the UE should include DL resources available to the UE. The BS assigns UL resources and DL resources to the UE through resource allocation. The resource allocations may include Time Domain Resource Allocation (TDRA) and Frequency Domain Resource Allocation (FDRA). In this disclosure, UL resource allocation is also referred to as UL grant, and DL resource allocation is referred to as DL assignment. UL grants are received dynamically by the UE on PDCCH or in RAR, or semi-permanently configured by BS for the UE through RRC signaling. The DL assignment is received dynamically by the UE on the PDCCH or semi-permanently configured for the UE by the BS through RRC signaling.

On the UL, the BS may dynamically allocate UL resources to the UE through a PDCCH addressed to a cell radio network temporary identifier (C-RNTI). The UE monitors the PDCCH to find possible UL grants for UL transmissions. The BS may allocate UL resources to the UE using the configuration grant. Two types of configuration permissions, type 1 and type 2, may be used. In type 1, the BS directly provides the configured UL grant (including periodicity) through RRC signaling. In type 2, the BS may configure the periodicity of RRC configuration UL grants through RRC signaling, and signal, enable, or disable the configured UL grants through PDCCH addressed to the configuration scheduling RNTI (CS-RNTI). For example, in type 2, the PDCCH addressed to the CS-RNTI indicates that the corresponding UL grant may be implicitly reused according to the periodicity configured through RRC signaling until deactivated.

On DL, the BS may dynamically allocate DL resources to the UE through a PDCCH addressed to the C-RNTI. The UE monitors the PDCCH to find possible DL grants. The BS may allocate DL resources to the UE using SPS. The BS may configure the periodicity of the configured DL assignment through RRC signaling, and signal, enable, or disable the configured DL assignment through PDCCH addressed to the CS-RNTI. For example, the PDCCH addressed to the CS-RNTI indicates that the corresponding DL assignment can be implicitly reused according to the periodicity configured through RRC signaling until deactivated.

Hereinafter, resource allocation through the PDCCH and resource allocation through the RRC will be described in more detail.

* Resource allocation by PDCCH: dynamic permissions/assignments

The PDCCH may be used to schedule DL transmissions on PDSCH and UL transmissions on PUSCH. The DCI on the PDCCH used to schedule the DL transmission can include a DL resource assignment including at least a modulation and coding format (e.g., a Modulation and Coding Scheme (MCS)) index I associated with the DL-SCH _MCS ) Resource allocation and HARQ information. The DCI on the PDCCH for scheduling UL transmission may include UL scheduling grant including at least modulation and coding format, resource allocation, and HARQ information associated with the UL-SCH. The HARQ information about the DL-SCH or UL-SCH may include a new information indicator (NDI), a Transport Block Size (TBS), a Redundancy Version (RV), and a HARQ process ID (i.e., HARQ process number). The size and purpose of DCI carried by one PDCCH differ according to DCI formats. For example, DCI format 0_0, DCI format 0_1, or DCI format 0_2 may be used to schedule PUSCH, and DCI format 1_0, DCI format 1_1, or DCI format 1_2 may be used to schedule PDSCH. Specifically, DCI format 0_2 and DCI format 1_2 may be used to schedule a packet with a transmission reliability and delay guaranteed to be greater than DCI format 0_0, DCI format 0_1, DCI format 1_0, or DCI format 1_1 Higher transmission reliability and lower latency requirements are sought. Some implementations of the present disclosure may be applied to UL data transmission based on DCL format 0_2. Some implementations of the present disclosure may be applied to DL data reception based on DCI format 1_2.

Fig. 7 shows an example of PDSCH TDRA caused by PDCCH and an example of PUSCH TDRA caused by PDCCH.

The DCI carried by the PDCCH to schedule the PDSCH or PUSCH includes a TDRA field. The TDRA field provides a value m of a row index m+1 for an allocation table of PDSCH or PUSCH. The predefined default PDSCH time domain allocation is applied as an allocation table of PDSCH, or the BS is applied as an allocation table of PDSCH through PDSCH TDRA table configured by RRC signal PDSCH-timedomainalllocation list. The predefined default PUSCH time domain allocation is applied as an allocation table of PUSCH, or the BS applies as an allocation table of PUSCH through PUSCH TDRA table configured by RRC signal PUSCH-timedomainalllocation list. The PDSCH TDRA table to be applied and/or the PUSCH TDRA table to be applied may be determined according to fixed/predefined rules (e.g. with reference to 3gpp TS 38.214).

In PDSCH time domain resource configuration, each index row defines DL assignment and PDSCH slot offset K ₀ The starting and length indicator values SLIV (or starting position (e.g., starting symbol index S) and allocation length (e.g., number of symbols L)) of PDSCH in a direct slot), and PDSCH mapping type. In PUSCH time domain resource configuration, each index row defines UL grant and PUSCH slot offset K ₂ A starting position (e.g., starting symbol index S) and an allocation length (e.g., number of symbols L) of PUSCH in a slot, and a PUSCH mapping type. K of PDSCH ₀ And PUSCH K ₂ The difference between the slot with PDCCH and the slot with PDSCH or PUSCH corresponding to PDCCH is indicated. The SLIV represents a joint indicator with respect to a start symbol S of the start of a slot having the PDSCH or PUSCH and the number L of consecutive symbols counted from the symbol S. There are two PDSCH/PUSCH mapping types: one is mapping type a and the other is mapping type B. In case of PDSCH/PUSCH mapping type a, DMRS is mapped to PDSCH/PUSCH resources with respect to the beginning of a slot. One or both of the PDSCH/PUSCH resources according to other DMRS parametersThe symbol may be used as a DMRS symbol. For example, in case of PDSCH/PUSCH mapping type a, the DMRS is located in the third symbol (symbol # 2) or the fourth symbol (symbol # 3) in the slot according to RRC signaling. In case of PDSCH/PUSCH mapping type B, DMRS is mapped with respect to the first OFDM symbol of PDSCH/PUSCH resources. One or two symbols from the first symbol of PDSCH/PUSCH resources may be used as DMRS symbols according to other DMRS parameters. For example, in case of PDSCH/PUSCH mapping type B, the DMRS is located at the first symbol allocated for PDSCH/PUSCH. In the present disclosure, the PDSCH/PUSCH mapping type may be referred to as a mapping type or DMRS mapping type. For example, in the present disclosure, PUSCH mapping type a may be referred to as mapping type a or DMRS mapping type a, and PUSCH mapping type B may be referred to as mapping type B or DMRS mapping type B.

The scheduling DCI includes an FDRA field providing assignment information on RBs for a PDSCH or PUSCH. For example, the FDRA field provides information about a cell for PDSCH or PUSCH transmission to the UE, information about BWP for PDSCH or PUSCH transmission, and/or information about RB for PDSCH or PUSCH transmission.

* Resource allocation by RRC

As described above, there are two types of transmissions without dynamic permissions: configuration license type 1 and configuration license type 2. In configuration grant type 1, UL grant is provided by RRC and stored as configuration UL grant. In configuration grant type 2, UL grants are provided by the PDCCH and stored or cleared as configuration UL grants based on L1 signaling indicating configuration UL grant enablement or disablement. Type 1 and type 2 may be configured by RRC per serving cell and per BWP. Multiple configurations may be active simultaneously on different serving cells.

When configuring configuration grant type 1, the following parameters may be provided to the UE through RRC signaling:

-CS-RNTI corresponding to CS-RNTI for retransmission;

periodicity corresponding to the periodicity of configuration license type 1;

-timeDomainOffset indicating a resource offset in the time domain relative to a System Frame Number (SFN) =0;

-a timedomainalillocation value m providing a row index m+1 pointing to the allocation table, indicating a combination of start symbol S, length L and PUSCH mapping type;

-frequency domain allocation; and

-mcsAndTBS providing I indicating modulation order, target code rate and transport block size _MCS 。

When configuring configuration grant type 1 for a serving cell through RRC, the UE stores UL grant provided by RRC as the indicated configuration UL grant for the serving cell and initializes or reinitializes the configuration UL grant to start with a symbol according to timeDomainOffset and S (derived from SLIV) and repeat at periodicity. After configuring the UL grant for configuration grant type 1, the UE may consider the UL grant to repeat with each symbol association satisfying the following equation: [ (SFN numberOfSlotsPerFrame (numberOfSymbolsPerSlot) + (number of slots in frame x number of symbols per slot) +number of symbols in slots ] = (timeDomainOffset x number of symbols per slot+s+n x periodic) module (1024 x number of symbols per frame x number of symbols per slot), where number of symbols per frame and number of consecutive OFDM symbols per slot are indicated for all N > =0, respectively (see tables 1 and 2).

For configuration grant type 2, the bs may provide the following parameters to the UE through RRC signaling:

-CS-RNTI corresponding to CS-RNTI for enabling, disabling and retransmitting; and

Periodicity providing periodicity of configuration license type 2.

The actual UL grant is provided to the UE through PDCCH (addressed to CS-RNTI). After configuring the UL grant for configuration grant type 2, the UE may consider the UL grant to repeat with each symbol association satisfying the following equation: [ (SFN x number ofslotsperframe x number ofsymbol perslot) + (number of slots in frame x number of symbols in slot) +]＝[(SFN _{Start time} *numberOfSlotsPerFrame*numberOfSymbolsPerSlot+slot _{Start time} *numberOfSymbolsPerSlot+symbol _{Start time} )+N*periodicity]Modulo (1024 x numberOfSlotsPerframe x numberOfSymbsPerslot) for allN>=0, wherein SFN _{Start time} 、slot _{Start time} And symbol _{Start time} SFN, slot and symbol, respectively, representing the first transmission opportunity of PUSCH after configuration grant is (re) initialized, number ofslotsperframe and number ofsymbolsperslot indicate the number of consecutive slots per frame and the number of consecutive OFDM symbols per slot, respectively (refer to tables 1 and 2).

In some scenarios, the UE may be further provided by the BS with parameters HARQ-ProcID-Offset and/or parameters HARQ-ProcID-Offset2 for deriving HARQ process IDs configuring UL grants. The HARQ-ProcID-Offset is an Offset of the HARQ process configuring the grant for the shared spectrum channel access operation, and the HARQ-ProcID-Offset2 is an Offset of the HARQ process configuring the grant. In the present disclosure, cg-retransmission timer is the duration after transmission (retransmission) based on configuration grant, where the UE should not autonomously perform retransmission based on HARQ process of transmission (retransmission). Cg-retransmission timer may be provided to the UE by the BS when configuring retransmissions for configuring UL grants. For configuration grants that do not configure neither HARQ-ProcID-Offset nor cg-retransmission timer, the HARQ process ID associated with the first symbol of the UL transmission may be derived from: HARQ process id= [ floor (current_symbol/periodicity) ] module nrofHARQ-Processes. For a configured UL grant with HARQ-ProcID-Offset2, the HARQ process ID associated with the first symbol of the UL transmission may be derived from: HARQ process id= [ current_symbol/periodicity) ] module nrofHARQ-process+harq-ProcID-Offset 2, wherein current_symbol= (SFN x number of slots in number of slots of number symbols per slot + frame, and number of slots per frame and number of consecutive OFDM symbols per slot, respectively. For a configuration UL grant with cg-retransmission timer, the UE may select a HARQ process ID from among HARQ process IDs available for configuration grant configuration.

On DL, semi-persistent scheduling (SPS) may be provided to the UE through RRC signaling from the BS per serving cell and per BWP. For DL SPS, DL assignments are provided to the UE over the PDCCH and stored or cleared based on L1 signaling indicating SPS activation or deactivation. When configuring SPS, the BS may provide the following parameters to the UE through RRC signaling (e.g., SPS configuration) for configuring semi-persistent transmission:

-CS-RNTI corresponding to CS-RNTI for enabling, disabling and retransmitting;

-nrofHARQ-Processes, providing the number of HARQ Processes for SPS;

-periodicity providing periodicity of configuration DL assignment for SPS;

n1PUCCH-AN, HARQ resources of PUCCH for SPS are provided (the network configures HARQ resources to format 0 or format 1, and the actual PUCCH resources are configured by PUCCH-Config and referenced by its ID in n1 PUCCH-AN).

Multiple DL SPS configurations may be configured within the BWP of the serving cell. After configuring DL assignments for SPS, the UE may consider that the nth DL assignment occurs in sequence in a slot satisfying the following equation: (numberOfSlotsPerFrame SFN + number of slots in frame) = [ (numberOfSlotsPerFrame SFN) _{Start time} +slot _{Start time} )+N*periodicity*numberOfSlotsPerFrame/10]Modulo (1024 x numberOfSlotsPerframe), where SFN _{Start time} And slot _{Start time} The SFN and slot, respectively, representing the first transmission of PDSCH after configuration DL assignment is (re) initialized, the numberOfSlotsPerFrame and numberOfSymbolsPerSlot indicate the number of consecutive slots per frame and the number of consecutive OFDM symbols per slot, respectively (refer to tables 1 and 2).

In some scenarios, the UE may be further provided by the BS with a parameter HARQ-ProcID-Offset for deriving the HARQ process ID configuring the DL assignment. The HARQ-ProcID-Offset is the Offset of the HARQ process of the SPS. For a configuration DL assignment without HARQ-ProcID-Offset, the HARQ process ID associated with the slot from which the DL transmission starts may be determined from: HARQ process id= [ floor (current_slot 10/(numberofslot perframe)) ] module nrofHARQ-Processes, wherein current_slot= [ (SFN x number slot perframe) +slot number in the frame ], and numberofslot perframe represents the number of consecutive slots per frame. For a configured DL assignment with HARQ-ProcID-Offset, the HARQ process ID associated with the slot from which the DL transmission starts may be determined from: HARQ process id= [ floor (current_slot/periodicity) ] module nrofHARQ-process+harq-ProcID-Offset, where current_slot= [ (SFN x number slot perframe) +number of slots in frame ], and number slot perframe represents the number of consecutive slots per frame.

If the CRC of the corresponding DCI format is scrambled with a CS-RNTI provided by an RRC parameter CS-RNTI and a new data indicator field of an enabled transport block is set to 0, the UE verifies the DL SPS assignment PDCCH or configures the UL grant type 2PDCCH for scheduling enablement or scheduling release. If all fields of the DCI format are set according to tables 6 and 7, verification of the DCI format is achieved. Table 6 shows an example of a special field for DL SPS and UL grant type 2 scheduling enable PDCCH verification, and table 7 shows an example of a special field for DL SPS and UL grant type 2 scheduling release PDCCH verification.

TABLE 6

TABLE 7

	DCI Format 0_0	DCI Format 1_0
			HARQ process number	All set to "0"	All set to "0"
Redundancy version	Set to "00"	Set to "00"
			Modulation and coding scheme	All set to "1"	All set to "1"
Resource block assignment	All set to "1"	All set to "1"

The actual DL assignment and UL grant for DL SPS or UL grant type 2 and the corresponding MCS are provided by resource assignment fields (e.g., a TDRA field providing a TDRA value m, an FDRA field providing a frequency resource block assignment, and/or an MCS field) in the DCI format carried by the corresponding DL SPS or UL grant type 2 scheduling enable PDCCH. If authentication is achieved, the UE treats the information in the DCI format as a valid enablement or valid release of DL SPS or configuration UL grant type 2.

In the present disclosure, a DL SPS-based PDSCH may be referred to as an SPS PDSCH, and a UL Configuration Grant (CG) -based PUSCH may be referred to as a CG PUSCH. The PDSCH dynamically scheduled by DCI carried on PDCCH may be referred to as a Dynamic Grant (DG) PDSCH and the PUSCH dynamically scheduled by DCI carried on PDCCH may be referred to as a DG PUSCH.

Fig. 8 illustrates a HARQ-ACK transmission/reception procedure.

Referring to fig. 8, the ue may detect a PDCCH in a slot n. Next, the UE may receive the PDSCH in the slot n+k0 according to scheduling information received through the PDCCH in the slot n and then transmit the UCI through the PUCCH in the slot n+k1. In this case, the UCI includes a HARQ-ACK response to the PDSCH.

DCI (e.g., DCI format 1_0 or DCI format 1_1) carried by a PDCCH for scheduling PDSCH may include the following information.

-FDRA: FDRA indicates the set of RBs allocated to PDSCH.

-TDRA: the TDRA indicates DL assignment and PDSCH slot offset K0, starting position (e.g., symbol index S) and length (e.g., number of symbols L) of PDSCH in the slot, and PDSCH mapping type. PDSCH mapping type a or PDSCH mapping type B may be indicated by TDRA. For PDSCH mapping type a, the DMRS is located in the third symbol (symbol # 2) or the fourth symbol (symbol # 3) in the slot. For PDSCH mapping type B, DMRS is allocated in the first symbol allocated for PDSCH.

PDSCH-to-harq_feedback timing indicator: the indicator indicates K1.

The HARQ-ACK response may consist of one bit if the PDSCH is configured to transmit at most one TB. If the PDSCH is configured to transmit a maximum of 2 TBs, the HARQ-ACK response may consist of 2 bits when spatial bundling is not configured and one bit when spatial bundling is configured. When the HARQ-ACK transmission timing for the plurality of PDSCH is designated as the slot n+k1, UCI transmitted in the slot n+k1 includes HARQ-ACK responses for the plurality of PDSCH.

In this disclosure, a HARQ-ACK payload composed of HARQ-ACK bits of one or more PDSCH may be referred to as a HARQ-ACK codebook. According to the HARQ-ACK payload determination scheme, the HARQ-ACK codebook may be classified into i) a semi-static HARQ-ACK codebook, ii) a dynamic HARQ-ACK codebook, and iii) a HARQ-ACK codebook based on HARQ processes.

In the case of a semi-static HARQ-ACK codebook, parameters related to the HARQ-ACK payload size to be reported by the UE are determined semi-statically by the (UE-specific) higher layer (e.g., RRC) signal. The HARQ-ACK payload size of the semi-static HARQ-ACK codebook (e.g., the (maximum) HARQ-ACK payload (size) transmitted through one PUCCH in one slot) may be determined based on the number of HARQ-ACK bits corresponding to a combination (hereinafter, bundling window) of all DL carriers (i.e., DL serving cells) configured for the UE and all DL scheduling slots (or PDSCH transmission slots or PDCCH monitoring slots) that may indicate HARQ-ACK transmission timing. That is, in the semi-static HARQ-ACK codebook scheme, the size of the HARQ-ACK codebook is fixed (at a maximum value) regardless of the amount of DL data actually scheduled. For example, DL grant DCI (PDCCH) includes PDSCH and HARQ-ACK timing information, and the PDSCH and HARQ-ACK timing information may have one of a plurality of values (e.g., k). For example, when PDSCH is received in slot # m and PDSCH and HARQ-ACK timing information in DL grant DCI (PDCCH) for scheduling PDSCH indicates k, HARQ-ACK information of PDSCH may be transmitted in slot # (m+k). By way of example, k ε {1,2,3,4,5,6,7,8}. When the HARQ-ACK information is transmitted in the slot #n, the HARQ-ACK information may include the maximum possible HARQ-ACK based on the bundling window. That is, the HARQ-ACK information of the slot #n may include HARQ-ACKs corresponding to the slot# (n-k). For example, when k e {1,2,3,4,5,6,7,8}, the HARQ-ACK information for slot # n may include HARQ-ACKs corresponding to slot # (n-8) to slot # (n-1) regardless of actual DL data reception (i.e., maximum number of HARQ-ACKs). Here, the HARQ-ACK information may be replaced by a HARQ-ACK codebook or a HARQ-ACK payload. The time slot may be understood/replaced with a candidate occasion for DL data reception. As described in the examples, the bundling window may be determined based on PDSCH and HARQ-ACK timing based on HARQ-ACK slots, and the PDSCH and HARQ-ACK timing set may have predefined values (e.g., {1,2,3,4,5,6,7,8 }) or may be configured by higher layer (RRC) signaling. The semi-static HARQ-ACK codebook is referred to as a type 1HARQ-ACK codebook. For a type 1HARQ-ACK codebook, the number of bits to be transmitted in the HARQ-ACK report is fixed and may be large. If many cells are configured, but only a few cells are scheduled, the type 1HARQ-ACK codebook may be inefficient.

In the case of a dynamic HARQ-ACK codebook, the HARQ-ACK payload size to be reported by the UE may be dynamically changed by DCI or the like. The dynamic HARQ-ACK codebook is referred to as a type 2HARQ-ACK codebook. The type 2HARQ-ACK codebook may be considered as optimized HARQ-ACK feedback because the UE only sends feedback for the scheduled serving cell. However, under poor channel conditions, the UE may erroneously determine the number of scheduled serving cells. To address this issue, a Downlink Assignment Index (DAI) may be included as part of the DCI. For example, in a dynamic HARQ-ACK codebook scheme, DL scheduling DCI may include counter-DAI (i.e., c-DAI) and/or total-DAI (i.e., t-DAI). Here, the DAI indicates a downlink assignment index and is used for the BS to inform the UE of the PDSCH of which HARQ-ACK is to be included in one HARQ-ACK transmission transmitted or scheduled. Specifically, c-DAI is an index indicating an order between PDCCHs carrying DL scheduling DCI (hereinafter, DL scheduling PDCCHs), and t-DAI is an index indicating a total number of DL scheduling PDCCHs until a current slot of a PDCCH having t-DAI exists.

In the case of HARQ-ACK codebook based HARQ processes, the HARQ-ACK payload is determined based on all HARQ processes of all configured (or enabled) serving cells in the PUCCH group. For example, the size of the HARQ-ACK payload that the UE is to use HARQ-ACK codebook reporting based on HARQ processes may be determined based on the number of serving cells and the number of HARQ processes of the serving cells that are all configured or enabled in the PUCCH group configured for the UE. The HARQ-ACK codebook based on HARQ processes is also referred to as a type 3HARQ-ACK codebook. The type 3HARQ-ACK codebook may be applied to one-time feedback.

Fig. 9 shows an example of multiplexing UCI with PUSCH. When PUCCH resources and PUSCH resources overlap in slots and PUCCH-PUSCH simultaneous transmission is not configured, UCI may be transmitted on PUSCH as shown. The transmission of UCI on PUSCH is referred to as UCI piggybacking or PUSCH piggybacking. Specifically, fig. 9 shows a case where HARQ-ACK and CSI are carried on PUSCH resources.

When a plurality of UL channels overlap within a predetermined time interval, a method of designating the UE to process the UL channels is required in order to allow the BS to correctly receive the UL channels. Hereinafter, a method of handling collision between UL channels will be described.

Fig. 10 illustrates an example of a process of processing a collision between UL channels by a UE having overlapping PUCCHs in a single slot.

To transmit UCI, the UE may determine PUCCH resources for each UCI. Each PUCCH resource may be defined by a start symbol and a transmission interval. When PUCCH resources for PUCCH transmission overlap in a single slot, the UE may perform UCI multiplexing based on the PUCCH resource having the earliest starting symbol. For example, the UE may determine (in time) overlapping PUCCH resources (hereinafter, PUCCH resource B) based on the PUCCH resource having the earliest starting symbol in the slot (hereinafter, PUCCH resource a) (S1001). The UE may apply UCI multiplexing rules to PUCCH resource a and PUCCH resource B. For example, based on UCI a of PUCCH resource a and UCI B of PUCCH resource B, MUX UCI including all or part of UCI a and UCI B may be obtained according to UCI multiplexing rules. In order to multiplex UCI associated with PUCCH resource a and PUCCH resource B, the UE may determine a single PUCCH resource (hereinafter, MUX PUCCH resource) (S1003). For example, the UE determines a PUCCH resource set (hereinafter, PUCCH resource set X) corresponding to a payload size of the MUX UCI among PUCCH resource sets configured or available to the UE for the UE, and determines one of PUCCH resources belonging to the PUCCH resource set X as a MUX PUCCH resource. For example, using a PUCCH resource indicator field in the last DCI among DCIs having PDSCH to HARQ feedback timing indicator fields indicating the same slot for PUCCH transmission, the UE may determine one of PUCCH resources belonging to PUCCH resource set X as MUX PUCCH resource. The UE may determine the total number of PRBs of the MUX PUCCH resource based on the payload size of the MUX UCI and the maximum code rate of the PUCCH format of the MUX PUCCH resource. If the MUX PUCCH resource overlaps with other PUCCH resources (except for PUCCH resource a and PUCCH resource B), the UE may perform the above operation again based on the MUX PUCCH resource (or the PUCCH resource having the earliest starting symbol among the other PUCCH resources including the MUX PUCCH resource).

Fig. 11 illustrates a case where UCI multiplexing is performed based on fig. 10. Referring to fig. 11, when a plurality of PUCCH resources overlap in a slot, UCI multiplexing may be performed based on an earliest PUCCH resource a (e.g., PUCCH resource a having an earliest starting symbol). In fig. 11, case 1 and case 2 show that a first PUCCH resource overlaps with another PUCCH resource. In this case, the process of fig. 10 may be performed in a state where the first PUCCH resource is regarded as the earliest PUCCH resource a. In contrast, case 3 shows that the first PUCCH resource does not overlap with another PUCCH resource and the second PUCCH resource overlaps with another PUCCH resource. In case 3, UCI multiplexing is not performed on the first PUCCH resource. In contrast, the process of fig. 10 may be performed in a state where the second PUCCH resource is regarded as the earliest PUCCH resource a. Case 2 shows that the MUX PUCCH resource determined to transmit the multiplexed UCI overlaps with another PUCCH resource again. In this case, the process of fig. 10 may be additionally performed in a state where the MUX PUCCH resource (or the earliest PUCCH resource (e.g. PUCCH resource with earliest starting symbol) among other PUCCH resources including the MUX PUCCH resource) is regarded as the earliest PUCCH resource a.

Fig. 12 shows the processing of collisions between UL channels by UEs having overlapping PUCCHs and PUSCHs in a single slot.

To transmit UCI, the UE may determine PUCCH resources (S1201). The determination of PUCCH resources for UCI may include determining MUX PUCCH resources. In other words, the determination of PUCCH resources for UCI by the UE may include determining MUX PUCCH resources based on a plurality of overlapping PUCCHs in the slot.

The UE may perform UCI piggyback on PUSCH resources based on the determined (MUX) PUCCH resources (S1203). For example, when there are PUSCH resources on which UCI transmission is allowed to be multiplexed, the UE may apply UCI multiplexing rules to PUCCH resources overlapping (on the time axis) with PUSCH resources. The UE may send UCI on PUSCH.

When there is no PUSCH overlapping the determined PUCCH resource in the slot, S1203 is omitted, and UCI may be transmitted on the PUCCH.

When the determined PUCCH resource overlaps with the plurality of PUSCHs on the time axis, the UE may multiplex UCI with one of the PUSCHs. For example, when the UE intends to transmit PUSCH to a corresponding serving cell, the UE may multiplex UCI on PUSCH of a specific serving cell (e.g., serving cell having the smallest serving cell index) among the serving cells. When there is more than one PUSCH in a slot of a particular serving cell, the UE may multiplex UCI on the earliest PUSCH transmitted in the slot.

Fig. 13 illustrates UCI multiplexing considering a timeline condition. When the UE performs UCI and/or data multiplexing for PUCCH and/or PUSCH overlapping on the time axis, the UE may lack processing time for UCI and/or data multiplexing due to flexible UL timing configuration for PUCCH or PUSCH. In order to prevent the processing time of the UE from being insufficient, two timeline conditions (hereinafter, multiplexing timeline conditions) described below are considered in performing UCI/data multiplexing for the overlapping PUCCHs and/or PUSCHs (on the time axis).

(1) The last symbol of PDSCH corresponding to HARQ-ACK information is received before time T1 from the start symbol of the earliest channel among the overlapped PUCCHs and/or PUSCHs (on the time axis). T1 may be based on i) a minimum PDSCH processing time N defined in terms of UE processing capability ₁ And/or ii) d predefined as an integer equal to or greater than 0 according to the location of the scheduling symbol, PDSCH mapping type, BWP switch, etc _1,1 To determine.

For example, the number of the cells to be processed,t1 may be determined as follows: t1= (n1+d) _1,1 )*(2048+144)*κ*2 ^-u *T _c . N1 is based on u of tables 8 and 9 for UE processing capacities #1 and #2, respectively, and μ is (μ) _PDCCH ,μ _PDSCH ,μ _UL ) One leading to a maximum T1, where μ _PDCCH μ corresponds to the subcarrier spacing of the PDCCH for scheduling PDSCH _PDSCH Subcarrier spacing, μ corresponding to scheduled PDSCH _UL Subcarrier spacing corresponding to UL channel to which HARQ-ACK is to be transmitted, and κ=t _c /T _f =64. In Table 8, at N _1,0 In the case of (2), if the PDSCH DMRS position of the added DMRS is l ₁ =12, then N _1,0 =14, otherwise, N _1,0 =13 (refer to section 7.4.1.1.2 of 3gpp TS 38.211). If the last symbol of PDSCH for PDSCH mapping type a exists on the i-th slot, then for i<7，d _1,1 =7-i, otherwise, d _1,1 =0. If the PDSCH has a mapping type B for UE processing capability #1, d when the number of allocated PDSCH symbols is 7 _1,1 May be 0, d when the number of allocated PDSCH symbols is 4 _1,1 May be 3, d when the number of allocated PDSCH symbols is 2 _1,1 May be 3+d, where d is the number of overlapping symbols of the scheduled PDCCH and the scheduled PDSCH. If the PDSCH mapping type is B for UE processing capability #2, d when the number of allocated PDSCH symbols is 7 _1,1 May be 0 and d when the number of allocated PDSCH symbols is 4 _1,1 May correspond to the number of overlapping symbols of the scheduled PDCCH and the scheduled PDSCH. Furthermore, if the number of allocated PDSCH symbols is 2, d when the scheduled PDSCH is within 3-symbol CORESET and PDSCH have the same starting symbol _1,1 May be 3, and for other cases d _1,1 May be the number of overlapping symbols of the scheduled PDCCH and the scheduled PDSCH. In the present disclosure, T1 may also be referred to as t_proc,1.

(2) The last symbol of the (e.g., trigger) PDCCH for indicating PUCCH or PUSCH transmission is received before time T2 from the start symbol of the earliest channel among the (on the time axis) overlapping PUCCHs and/or PUSCHs. T2 may be based on i) minimum PUSCH preparation time defined according to UE PUSCH timing capabilityM N ₂ And/or ii) d predefined as an integer equal to or greater than 0 according to scheduled symbol positions, BWP switching, etc _2,x To determine. d, d _2,x D, which can be categorized as being related to the position of the scheduled symbol _2,1 And d related to BWP handoff _2,2 。

For example, T2 may be determined as follows: t2=max { (n2+d) _2,1 )*(2048+144)*κ*2 ^-u *T _c +T _ext +T _switch ,d _2,2 }. N2 is based on u of tables 10 and 11 for UE timing capabilities #1 and #2, respectively, and μ is (μ) _DL ,μ _UL ) One leading to a maximum T1, where μ _DL Subcarrier spacing, μ corresponding to PDCCH carrying DCI for scheduling PUSCH _UL Subcarrier spacing corresponding to PUSCH, and κ=t _c /T _f =64. D if the first symbol of PUSCH allocation consists of DMRS only _2,1 May be 0, otherwise, d _2,1 May be 1. D if the scheduling DCI triggers a BWP handoff _2,2 Equal to the switching time, otherwise, d _2,2 Is 0. The switching time may be defined differently according to the Frequency Range (FR). For example, for FR1, the switching time may be defined as 0.5ms, and for FR2, as 0.25ms. In the present disclosure, T2 may also be referred to as t_proc,2.

The following table shows the processing time according to the UE processing capability. Specifically, table 8 shows PDSCH processing time for PDSCH processing capability #1 of the UE, table 9 shows PDSCH processing time for PDSCH processing capability #2 of the UE, table 10 shows PUSCH preparation time for PUSCH timing capability #1 of the UE, and table 11 shows PUSCH processing time for PUSCH timing capability #2 of the UE.

TABLE 8

TABLE 9

u/SCS	PDSCH decoding time N ₁ [ symbol ]]
		0/15kHz	3
1/30kHz	4.5
		2/60kHz	For frequency ranges 1,9

TABLE 10

u/SCS	PUSCH preparation time N ₂ [ symbol ]]
		0/15kHz	10
1/30kHz	12
		2/60kHz	23
3/120kHz	36

TABLE 11

u/SCS	PUSCH preparation time N ₂ [ symbol ]]
		0/15kHz	5
1/30kHz	5.5
		2/60kHz	For frequency range 1, 11

The UE may report PDSCH processing capability supported thereby to the BS for a carrier corresponding to one of the band entries in the band combination. For example, it may be reported whether the UE supports only PDSCH processing capability #1 or PDSCH processing capability #2 as UE capability with respect to the respective subcarrier spacing (SCS) supported in the corresponding frequency band. The UE may report to the BS regarding the carrier corresponding to one of the band entries in the band combination, thereby supporting PUSCH processing capability. For example, it may be reported whether the UE supports only PUSCH processing capability #1 or PUSCH processing capability #2 as UE capability with respect to the respective SCS supported in the corresponding frequency band.

If a UE configured to multiplex different UCI types within one PUCCH intends to transmit a plurality of overlapping PUCCHs in a slot or transmit overlapping PUCCHs and PUSCHs in a slot, the UE may multiplex UCI types when a specific condition is satisfied. The particular condition may include a multiplexed timeline condition. For example, PUCCH and PUSCH to which UCI multiplexing is applied in fig. 10 to 12 may be UL channels satisfying multiplexing timeline conditions. Referring to fig. 13, a ue may need to transmit a plurality of UL channels (e.g., UL channels #1 to # 4) in the same slot. Here, UL ch#1 may be a PUSCH scheduled by pdcch#1. UL ch#2 may be a PUCCH for transmitting HARQ-ACK for PDSCH. PDSCH is scheduled by pdcch#2, and resources of UL ch#2 may also be indicated by pdcch#2.

In this case, if UL channels (e.g., UL channels #1 to # 3) overlapping on the time axis satisfy the multiplexing time line condition, the UE may perform UCI multiplexing for UL channels #1 to #3 overlapping on the time axis. For example, the UE may check whether the first symbol of UL ch#3 from the last symbol of PDSCH satisfies the condition of T1. The UE may also check whether the first symbol of UL ch#3 satisfies the condition of T2 from the last symbol of pdcch#1. If the multiplexing timeline condition is satisfied, the UE may perform UCI multiplexing for UL channels #1 to # 3. In contrast, if the earliest UL channel (e.g., UL channel with earliest starting symbol) among the overlapping UL channels does not satisfy the multiplexing timeline condition, the UE may not be allowed to multiplex all corresponding UCI types.

In some scenarios, it is specified that the UE does not expect to transmit more than one PUCCH with HARQ-ACK information in one slot. Thus, according to these scenarios, the UE may transmit at most one PUCCH with HARQ-ACK information in one slot. In order to prevent a case where the UE fails to transmit HARQ-ACK information due to a limit on the number of HARQ-ACK PUCCHs that the UE can transmit, the BS needs to perform DL scheduling so that HARQ-ACK information can be multiplexed on one PUCCH resource. However, when considering delay and reliability-critical services (e.g., URLLC services), a scheme of focusing a plurality of HARQ-ACK feedback on only one PUCCH in a slot may be undesirable in terms of PUCCH performance. Further, in order to support the delay critical service, the BS may need to schedule a plurality of consecutive PDSCH of short duration in one slot. Although the UE may transmit PUCCH in random symbols in a slot through configuration/indication of the BS, if the UE is allowed to transmit only at most one HARQ-ACK PUCCH in a slot, the BS may not perform fast back-to-back scheduling of PDSCH and the UE may not perform fast HARQ-ACK feedback. Accordingly, multiple (non-overlapping) HARQ-ACK PUCCHs (or PUSCHs) may be allowed to be transmitted in one slot for more flexible and efficient resource usage and service support. Thus, in some scenarios, PUCCH feedback based on a slot comprising 14 OFDM symbols may be considered, as well as PUCCH feedback based on a sub-slot comprising less than 14 OFDM symbols (e.g. 2 to 7) OFDM symbols.

UL channels may be scheduled or triggered with different priorities. In some implementations of the disclosure, the priority of UL channels may be represented by a priority index, and UL channels with a greater priority index may be determined to have a higher priority than UL channels with a smaller priority index. In some implementations, the priority of the UL channel may be provided by DCI that schedules or triggers UL channel transmission or by RRC configuration regarding permissions configured for the UL channel. If the priority (or priority index) of the UL channel is not provided to the UE, the priority of the UL channel may be adjusted to a low priority (or priority index 0).

For HARQ-ACK feedback for multiple DL data channels (e.g., multiple PDSCH) with different service types, qoS, latency requirements, reliability requirements, and/or priorities, separate codebooks may be formed/generated. For example, the HARQ-ACK codebook for PDSCH associated with high priority and the HARQ-ACK codebook for PDSCH associated with low priority may be configured/formed separately. For HARQ-ACK feedback for PDSCH of different priorities, the respective PUCCH transmissions of different priorities may consider different parameters and resource configurations (see, e.g., information Element (IE) PUCCH-configuration list of 3gpp TS 38.331). For example, if the pdsch-HARQ-ACK-codebook list is provided to the UE through RRC signaling, the UE may be instructed to generate one or more HARQ-ACK codebooks through the pdsch-HARQ-ACK-codebook list. If the UE is instructed to generate one HARQ-ACK codebook, the HARQ-ACK codebook is associated with a PUCCH with priority index 0. If pdsch-HARQ-ACK-codebook list is provided to the UE, the UE multiplexes HARQ-ACK information associated with the same priority index only in the same HARQ-ACK codebook. If the UE is instructed to generate two HARQ-ACK codebooks, the first HARQ-ACK codebook is associated with a PUCCH of priority index 0 and the second HARQ-ACK codebook is associated with a PUCCH of priority index 1.

The unit of time difference between DL data channel and PUCCH transmission for HARQ-ACK feedback transmission (e.g., PDSCH-to-harq_feedback timing indicator) may be determined by a preconfigured sub-slot length (e.g., the number of symbols constituting a sub-slot). For example, a unit of a time difference from a DL data channel to a PUCCH for HARQ-ACK feedback transmission may be configured by a parameter "subslotLengthForPUCCH" in configuration information PUCCH-Config for configuring a UE-specific PUCCH parameter. According to these scenarios, the length units of PDSCH-to-HARQ feedback timing indicators may be configured for each HARQ-ACK codebook.

In some scenarios, UL or DL scheduling may be performed dynamically or semi-statically, and the BS may configure or indicate the transmission direction (e.g., DL, UL, or flexible) of each symbol to the UE semi-statically using a tdd-UL-DL-configuration command or a tdd-UL-DL-configuration decoded message or dynamically using DCI format 2_0. UL or DL scheduling configured by the configured/indicated transmission direction may also be cancelled.

In some scenarios, UL or DL scheduling may be performed dynamically or semi-statically, and the BS may configure or indicate the transmission direction (e.g., DL, UL, or flexible) of each symbol for or to the UE dynamically using tdd-UL-DL-configuration command or tdd-UL-DL-configuration decoded messages semi-statically or using DCI format 2_0. UL or DL scheduling configured by the configured/indicated transmission direction may also be cancelled.

Fig. 14 shows an exemplary HARQ-ACK delay.

In some scenarios (e.g., 3GPP NR Rel-16), if the UE receives a PDSCH scheduled by the BS, the UE may transmit a PUCCH carrying HARQ-ACK for the PDSCH (hereinafter, HARQ-ACK PUCCH) at a time specified by scheduling information of the PDSCH. However, this series of operations always causes the UE to transmit the PUCCH after a predetermined time elapses from the reception of the SPS PDSCH of the semi-persistent configuration. As a result, the TDD pattern misaligned with the period of the SPS PDSCH may be used, or PUCCH transmission may be easily canceled by dynamic TDD operation of the BS. Further, PDSCH transmission associated with the cancelled PUCCH transmission may also be cancelled or retransmission may be requested. To solve these problems, an operation in which the UE delays PUCCH timing determined for PDSCH in a prescribed or arbitrary manner, i.e., a delayed operation, is being considered. For example, when a transmission direction in which a PUCCH configured to carry HARQ-ACK for SPS PDSCH (hereinafter, SPS HARQ-ACK) is configured or indicated is canceled, it may be considered to delay HARQ-ACK transmission to a HARQ-ACK delay after an originally expected time. Referring to fig. 14, for example, when the SPS PDSCH in the slot #m-1 uses the HARQ process #i and when the HARQ-ACK transmission for the SPS PDSCH is scheduled in the slot #m, the UE may determine to defer the PUCCH for the HARQ-ACK transmission for the SPS PDSCH from the slot #m to the slot #n based on a predetermined condition. According to such HARQ-ACK delay, even if PUCCH transmission is cancelled, the UE and the BS may transmit/receive HARQ-ACK information for the SPS PDSCH later.

In some scenarios (e.g., LTE-based systems or NR Rel-16 based systems), the CCs (i.e., serving cells) for PUCCH transmission by a UE may be semi-statically configured through RRC signaling from the BS. In some scenarios, in order to enable the UE to transmit the PUCCH as soon as possible, it is being considered to dynamically switch the carrier (or cell) transmitting the PUCCH by determining the CC transmitting the PUCCH based on L1 signaling from the BS or by any determination by the UE, or to semi-statically switch the cell (or cell) transmitting the PUCCH according to a predefined rule. In this disclosure, switching CCs may refer to switching cells including CCs. In other words, carrier switching as described herein may mean switching from one cell to another or may also mean switching between carriers within a single cell.

Fig. 15 illustrates an exemplary PUCCH cell handover. For clarity of description, fig. 15 shows an example in which a cell transmitting PDSCH is different from a candidate PUCCH cell for PUCCH cell handover and SCS of a cell transmitting PDSCH is also different from SCS of the candidate PUCCH cell. However, PDSCH may be transmitted on candidate PUCCH cells, and SCS of a cell transmitting PDSCH may be the same as SCS of some candidate PUCCH cells.

In some implementations of the disclosure, when the UE is able to use multiple CCs, the UE may change the PUCCH transmission carrier (e.g., PUCCH cell) according to a predefined rule or based on L1 signaling provided by the BS, thereby enabling the UE to perform continuous UL transmission.

In some implementations, the UE may select PUCCH resources using a set of HARQ-ACK feedback timing values (e.g., dl-DataToUL-ACK-r16, or dl-DataToUL-ACK-DCI-1-2-r 16) configured on a primary cell of a PUCCH group that schedules PDSCH. For example, if the PUCCH group for scheduling PDSCH is MCG, the UE may determine HARQ-ACK feedback timing value K for PDSCH based on the set of HARQ-ACK feedback timing values configured on Pcell. If the PUCCH group of the scheduled PDSCH is SCG, the UE may determine the HARQ-ACK feedback timing value K of the PDSCH based on the set of HARQ-ACK feedback timing values configured on the PSCell of the SCG. If the PUCCH group of the scheduled PDSCH is the primary PUCCH group, the UE may determine the HARQ-ACK feedback timing value K of the PDSCH based on the set of HARQ-ACK feedback timing values configured on the Pcell. If the PUCCH group of the scheduled PDSCH is a secondary PUCCH group, the UE may determine the HARQ-ACK feedback timing value K of the PDSCH based on the HARQ-ACK feedback timing value set configured on the PUCCH-SCell of the secondary PUCCH group.

Referring to fig. 15, for example, for the DL slot n _D If no PUCCH cell handover is configured, supported or indicated, the UE may transmit PUCCH including HARQ-ACK information for PDSCH reception in UL slot n+k on the primary cell (e.g., cell a in fig. 15), where slot n is the same as slot n _D The last slots overlapping for PUCCH transmission and K may be provided by the determined HARQ-ACK feedback timing value K. In some implementations, the determined HARQ-ACK feedback timing value K may be counted based on time slots on the primary cell. On the other hand, when PUCCH cell handover is configured, supported or indicated, PUCCH cells may be determined according to predefined/preconfigured rules or L1 signaling for slots on the primary cell determined based on the determined HARQ-ACK feedback timing value K. For example, referring to fig. 15, when PUCCH cell handover is configured, supported, or indicated, and when a PUCCH cell of a slot n+2 is determined as a cell B according to a predefined/preconfigured rule or L1 signaling, the UE may perform PUCCH transmission for PDSCH in an earliest slot (slot m) overlapping with a slot n+2 on a cell a, for example, among slots on the cell B, instead of performing PUCCH transmission for PDSCH in a slot n+2 on the cell a.

As described above, HARQ-ACK transmission delay and PUCCH carrier switching are being considered to solve the following problems: transmission of HARQ-ACK for SPS PDSCH is not allowed in TDD environment; and long delays occur in a TDD environment. In other words, HARQ-ACK delay and PUCCH cell switching are being considered to enable the UE to perform PUCCH transmission as soon as possible. A commonality of dynamically switching PUCCH carriers or delaying transmission of HARQ-ACKs is that UL transmissions on resources that are not available for transmission due to TDD operation are performed on other available resources. Thus, both HARQ-ACK transmission delay (i.e., HARQ-ACK delay) and PUCCH carrier switching (i.e., PUCCH cell switching) may be required. Since the effects achievable by HARQ-ACK delay and PUCCH cell switching are also similar, it may be desirable for the UE and BS to perform one of two operations when HARQ-ACK delay and PUCCH cell switching are required. For example, if the UE is able to perform HARQ-ACK deferral and PUCCH cell switching in a slot in which HARQ-ACK transmission is not allowed, the UE may transmit HARQ-ACK with lower delay by performing only PUCCH cell switching without deferring HARQ-ACK transmission. Alternatively, the UE may perform only the HARQ-ACK deferral, but the UE may consider the effect of PUCCH cell handover while performing the HARQ-ACK deferral.

However, when the UE supports both HARQ-ACK delay and PUCCH cell handover and the UE selects one of the two operations, more specifically, when the UE autonomously determines one of the two operations, it needs to be considered how the BS will operate.

Hereinafter, an implementation of the present disclosure that realizes lower delay by combining the above two methods will be described by assuming that each time a UE transmits PUCCH, the UE can dynamically switch carriers for PUCCH transmission by determining a CC for the UE to perform PUCCH transmission based on L1 signaling (e.g., DCI) from a BS or by determining a CC (arbitrarily or according to a predetermined rule), and the UE can delay transmission of HARQ-ACK for SPS PDSCH according to a TDD configuration. For example, an implementation of the present disclosure that allows HARQ-ACKs to be transmitted in earlier slots by considering PUCCH cell switching during HARQ-ACK deferral operations will be described.

In some implementations of the present disclosure, if the UE is able to use multiple CCs, the UE may switch PUCCH transmission carriers according to a predefined rule (PUCCH carrier switching) or delay HARQ-ACK transmission (HARQ-ACK delay) that is not allowed due to TDD operation to perform continuous UL transmission. In this case, according to some implementations of the present disclosure, the UE may determine whether to perform PUCCH carrier switching or HARQ-ACK deferral for UL transmissions configured/indicated on unavailable resources based on the TDD configuration and the CA configuration. The UE may also determine PUCCH carriers and PUCCH resources to be used for respective operations.

When performing the HARQ-ACK deferral, the UE may defer the HARQ-ACK transmission from the initially indicated/configured HARQ-ACK transmission slot (hereinafter referred to as an initial slot) to another slot (hereinafter referred to as a target slot).

If the UE is configured with an SCG, the UE may apply some implementations of the disclosure described below to both the MCG and the SCG. If some implementations of the present disclosure described below are applied to an MCG, the terms "secondary cell" and "serving cell" in the following description may refer to the secondary cell and the serving cell, respectively, belonging to the MCG. If some implementations of the present disclosure described below are applied to an SCG, the terms "secondary cell" (without PSCell) and "serving cell" in the following description may refer to secondary cells and serving cells, respectively, belonging to the SCG. Hereinafter, the term "primary cell" may refer to a Pcell of an MCG when some implementations of the present disclosure are applied to the MCG, and to a PSCell of an SCG when some implementations of the present disclosure are applied to the SCG.

When the UE is configured with a PUCCH-SCell, the UE may apply some implementations of the present disclosure described below to both the primary PUCCH group and the secondary PUCCH group. If some implementations of the present disclosure described below are applied to a primary PUCCH group, the terms "secondary cell" and "serving cell" in the following description may refer to a secondary cell and a serving cell, respectively, belonging to the primary PUCCH group. If some implementations of the present disclosure described below are applied to a secondary PUCCH group, the terms "secondary cell" (without PSCell) and "serving cell" in the following description may refer to a secondary cell and a serving cell, respectively, belonging to the secondary PUCCH group. Hereinafter, the term "primary cell" may refer to a Pcell of a primary PUCCH group when some implementations of the present disclosure are applied to the primary PUCCH group, and to a PUCCH-SCell of a secondary PUCCH group when some implementations of the present disclosure are applied to the secondary PUCCH group.

In the present disclosure, the term "carrier" or "Component Carrier (CC)" may refer to a cell including the above-described carriers. In other words, the term "carrier switch" may refer to switching from one cell to another or switching between carriers within a single cell.

UE side:

fig. 16 illustrates a HARQ-ACK transmission flow in accordance with some implementations of the present disclosure.

The UE may be provided with cell configuration when connected to the BS. The UE may obtain information about CCs available to the UE from the cell configuration. The BS may send a MAC Control Element (CE) message to the UE to enable or disable the respective carriers. When the BS schedules the UE to receive the PDSCH and transmit the PUCCH carrying the HARQ-ACK response thereto, the UE may dynamically select a carrier of the PUCCH to which the UE will transmit the HARQ-ACK response according to some implementations of the present disclosure. In addition, according to some implementations of the present disclosure, the UE may determine PUCCH resources to use on the corresponding carrier.

In some implementations, for example, the UE may receive scheduling information on PDSCH reception and scheduling information on PUCCH transmission of HARQ-ACK response thereto (S1601). If the UE supports HARQ-ACK extension and PUCCH cell switching, the UE may determine a PUCCH cell and PUCCH slot in which the UE will perform PUCCH transmission for scheduled PDSCH reception based on the HARQ-ACK extension and/or PUCCH cell switching according to some implementations of the present disclosure (S1603). The UE may perform PUCCH transmission including HARQ-ACK information received for the scheduled PDSCH in the determined PUCCH slot on the determined PUCCH cell (S1605).

The following are examples of UE operations according to some implementations of the present disclosure.

1) Upon connection to the BS, the UE may receive an RRC configuration including CC information (e.g., servingCellConfigCommon) from the BS through RRC signaling.

2) The UE may receive the SPS PDSCH configuration and the RRC configuration for deferring HARQ-ACK for the SPS PDSCH from the BS through RRC signaling.

3) The BS may send a MAC CE message to the UE to enable or disable the various carriers configured for the UE.

4) The BS may schedule the UE to perform PDSCH reception, SPS PDSCH release reception, and PUCCH transmission for HARQ-ACK response thereto.

5) The UE may determine whether to change the carrier of the PUCCH to transmit for the HARQ-ACK response and/or change the HARQ-ACK transmission time indicated/configured to the UE based on some implementations of the present disclosure.

6) The UE may determine PUCCH resources to use on the changed/determined carrier and/or at the changed/determined HARQ-ACK transmission time based on some implementations of the present disclosure.

In some implementations of the disclosure, DL symbols may refer to symbols included in at least one of:

-a set of symbols in a time slot indicated as DL by tdd-UL-DL-configuration command or tdd-UL-DL-configuration de-directed;

-a set of symbols in a slot indicated to the UE by PDCCH-ConfigSIB1 in a Master Information Block (MIB) of a control resource set (CORESET) of a Type0-PDCCH CSS set;

-a set of symbols in a slot indicated to the UE by ssb-locationinburst in systeminformatioblocktype 1 or by ssb-locationinburst in ServingCellConfigCommon for receiving an SS/PBCH block in any of a plurality of serving cells; or alternatively

-the SFI index field value is indicated as the set of symbols in the slot of DCI format 2_0 of DL.

In some implementations of the present disclosure, UL symbols may refer to symbols included in at least one of:

-a set of symbols in a time slot indicated as UL by tdd-UL-DL-configuration command or tdd-UL-DL-configuration de-directed;

-N preceding with an active PRACH occasion and an active PRACH occasion _gap Symbol sets in the time slots corresponding to the symbols; or alternatively

-the SFI index field value is indicated as the set of symbols in the slot of DCI format 2_0 of the UL.

The following UE operations according to some implementations of the present disclosure are mainly illustrated in the context of UCI transmission on PUCCH, more specifically, transmission of HARQ-ACK response to SPS PDSCH on PUCCH. However, the implementations of the present disclosure are applicable not only to transmission of HARQ-ACK responses for PDSCH scheduled by DCI, but also to PUSCH transmission and PUCCH transmission carrying other UCI.

In some implementations of the present disclosure, PUCCH carrier switching refers to an operation in which a UE arbitrarily changes a PUCCH carrier according to a predefined rule and performs PUCCH transmission as described above. The following rules may be considered as predefined rules.

When PUCCH radio resources are determined based on PRI included in DCI, and when DCI includes PUCCH carrier indication, UE may perform PUCCH carrier switching according to the PUCCH carrier indication.

The UE may be configured with a PUCCH carrier switching pattern through higher layer signaling of the BS.

The > PUCCH carrier switching pattern may mean information to list a list including one or more available UL CCs in order according to a specific time unit (e.g., several slots) within a specific time period (e.g., several tens of slots, one frame, or 10 ms).

>>To indicate that the list of available UL CCs occupies a specific time unit, a time length T may be included in each list _L . Length of time T _L The time taken by the corresponding list may be meant. In this case, the period of the PUCCH carrier switching pattern may be the time length T of the list of available UL CCs _L Is a sum of (a) and (b). For example, there may be a specific UL CC list l1= { C1, C2, C3}, and time information T may be additionally assigned to the list L1 _L . For example, l1= { { C1, C2, C3}, T may be provided _L }. In this case, it may be at time T _L During which at least one of C1, C2 or C3 is used. These lists may be enumerated sequentially. For example, if the list is given as { L1, L2, L3,..ln }, the sum of the time lengths T of the respective lists LN may represent the length of the entire pattern.

In some implementations, information indicating that PUCCH carrier switching is not performed for a specific duration may also be included in one or more patterns. This information can also be represented as a list of UL CCs including individual RRC parameters (e.g., nopucc hcarrierswitching). The UE may not perform PUCCH carrier switching for a duration including such information.

> the time unit or slot length (i.e., the length of time per slot) can be determined by UL SCS configuration configured in the cell. For example, at least one of the following may be considered.

> > individual UL reference SCS of PUCCH carrier switching pattern may be configured, and the time unit may be determined by a corresponding SCS value.

> > the time unit may be determined by the maximum or minimum SCS among SCSs of UL BWP configured for the UE.

> time units may be determined by a configurable maximum or minimum SCS in the cell. As an example, the time units may be determined by the minimum or maximum SCS configuration u provided by the freefinul or SCS-specificcarrier list of the freefinul-SIB.

When the length of one frame is 10ms, the slot length according to each SCS configuration u can be determined according to table 1.

< implementation A1> first delays within PUCCH carrier, then carrier switching

When the UE receives the SPS PDSCH configured/indicated by the BS and attempts to transmit a HARQ-ACK response to the SPS PDSCH, if HARQ-ACK transmission determined based on the indicated or configured PUCCH resources and PDSCH-to-HARQ-ACK timing is not allowed due to overlapping in time with one or more DL symbols, the UE may first perform a HARQ-ACK deferral procedure in an initial slot to determine a new target slot for transmitting the HARQ-ACK response and then transmit the HARQ-ACK response in the corresponding slot.

In addition, the UE may attempt PUCCH carrier switching to perform PUCCH transmission in an initial slot on another CC in the following case: when the UE is allowed to transmit the HARQ-ACK response at a position far from the end of the associated PDSCH reception or from the start time of the indicated PUCCH transmission by more than a time interval T (e.g., maximum delay limit) in the initial slot as a result of the HARQ-ACK delay procedure, i.e., due to the HARQ-ACK delay (e.g., when the HARQ-ACK response is allowed to be transmitted at a later time than t_pdsch+t or t_pucch+t, where t_pdsch and t_pucch are respectively the PDSCH reception end time and the PUCCH transmission start time); when an explicit delay budget (e.g., a packet delay budget) is given for a service associated with the HARQ-ACK response transmitted by the UE and it is determined that the determined target time slot is unlikely to meet the delay budget (e.g., the packet delay budget); or when it is difficult to successfully perform the HARQ-ACK deferral procedure for other reasons.

The time interval T may be predefined or may be determined by L1 signaling and/or higher layer signaling from the BS.

According to implementation A1, the UE may minimize the execution of the PUCCH carrier switching operation, thereby maximizing the utilization of channel information on a single CC acquired and maintained on a corresponding CC.

< implementation A2> first carrier switch and then delay

When the UE receives the SPS PDSCH configured/indicated by the BS and attempts to transmit a HARQ-ACK response to the SPS PDSCH, if HARQ-ACK transmission determined based on the indicated or configured PUCCH resources and PDSCH-to-HARQ-ACK timing is not allowed due to overlapping in time with one or more DL symbols, the UE may first attempt PUCCH carrier switching in an initial slot to perform PUCCH transmission. The UE may perform a HARQ-ACK deferral procedure if PUCCH transmission in the initial slot is not allowed after PUCCH carrier switching.

For example, the UE attempts HARQ-ACK PUCCH transmission in the initial slot based on PUCCH carrier switching if possible. If the UE is not allowed to transmit PUCCH in the initial slot despite PUCCH carrier switching (e.g., in case there are no CCs with enough UL symbols available for PUCCH transmission in the initial slot), the UE may additionally perform HARQ-ACK deferral to determine a new target slot for transmitting HARQ-ACK and then transmit HARQ-ACK response in the corresponding slot.

When the UE additionally performs HARQ-ACK deferral, the UE may perform HARQ-ACK deferral based on some implementations of the present disclosure. Accordingly, the UE may perform HARQ-ACK deferral considering a plurality of CCs and minimize a Round Trip Time (RTT) required for PDSCH reception.

Alternatively, in order to simplify UE operation, when the UE receives an SPS PDSCH configured/indicated by the BS and attempts to transmit a HARQ-ACK response to the SPS PDSCH, if HARQ-ACK transmission determined based on the indicated or configured PUCCH resources and PDSCH-to-HARQ-ACK timing is not allowed due to overlapping in time with one or more DL symbols, the UE may perform PUCCH transmission by attempting PUCCH carrier switching in an initial slot. The UE does not perform the HARQ-ACK deferral procedure even if PUCCH transmission is not allowed in the initial slot after PUCCH carrier switching. In other words, once the UE performs PUCCH carrier switching, the UE does not perform HARQ-ACK deferral procedures.

As another example, when PUCCH carrier switching is performed according to a PUCCH carrier switching pattern, the permission of PUCCH carrier switching in each case may be determined by the PUCCH carrier pattern. The UE may not perform PUCCH carrier switching at a position indicating the initial CC on the PUCCH carrier pattern, but may perform PUCCH carrier switching at a position indicating a carrier for switching. The UE may perform PUCCH carrier switching at a time when PUCCH carrier switching is allowed and perform HARQ-ACK deferral procedure in a period when PUCCH carrier switching is not allowed.

< implementation A2-1> delay after carrier switch

In case of using the implementation A2, when the UE receives the SPS PDSCH configured/indicated by the BS and attempts to transmit the HARQ-ACK response to the SPS PDSCH, if HARQ-ACK transmission determined based on the indicated or configured PUCCH resources and PDSCH-to-HARQ-ACK timing is not allowed due to overlapping in time with one or more DL symbols, the UE may first attempt PUCCH carrier switching in an initial slot to perform PUCCH transmission.

When the UE is explicitly configured with a target carrier for carrier switching to be used in a UL slot scheduling a corresponding PUCCH, the UE may perform a HARQ-ACK deferral procedure if PUCCH transmission is not allowed in an initial slot after PUCCH carrier switching. In this case, the following method can be considered.

* Method a2_1: the UE may perform carrier switching to a target carrier configured to be used in the initial slot and then delay PUCCH transmission to a target slot on the target carrier where the UE can perform PUCCH transmission. The UE may perform PUCCH carrier switching to the target carrier again if the UL carrier configured to be used in the target slot is different from the target carrier.

* Method a2_2: the UE may perform a HARQ-ACK deferral procedure on the original carrier to defer PUCCH transmission to a target slot on the original carrier where the UE can perform PUCCH transmission. The UE may perform carrier switching to a target carrier configured to be used in a target slot and then perform PUCCH transmission.

* Method a2_3: the UE may consider UL carriers configured for use in respective UL slots while performing the HARQ-ACK deferral procedure as in implementation A3/B3. For example, while looking for the first UL slot of the PUCCH that the UE is able to transmit a delay, the UE may consider the feasibility of transmission on the target UL carrier of the corresponding slot (e.g., the UL slot configuring the PUCCH carrier to be used). If PUCCH transmission is allowed, the UE may delay PUCCH transmission to a slot in which PUCCH transmission is allowed among slots of the target UL carrier.

< implementation A3> HARQ-ACK delay and PUCCH carrier switching

Fig. 17 illustrates a cell and a slot transmitting a HARQ-ACK response according to some implementations of the present disclosure.

When a UE configured with a plurality of CCs performs a HARQ-ACK deferral operation, more specifically, when the UE intends to transmit a HARQ-ACK response that should be transmitted in an initial slot on an initial CC indicated/configured by the BS, the UE may determine a target slot and a target CC for transmitting the HARQ-ACK response by considering the configured CC (even) in another slot (i.e., a target slot). For example, when a UE configured with a plurality of CCs is to perform (SPS) PDSCH reception configured/indicated by a BS and attempt to transmit a HARQ-ACK response to (SPS) PDSCH reception, the UE may determine a target slot and a target CC for actually performing HARQ-ACK transmission determined based on indicated or configured PUCCH resources and PDSCH-to-HARQ-ACK timing by considering the configured CCs and HARQ-ACK delays.

* Method a3_1: among slots within a predetermined time interval from the initial slot, CCs having consecutive available symbols (e.g., consecutive UL or flexible symbols) of PUCCH resources sufficient to transmit a HARQ-ACK response for a deferral may be selected as target PUCCH carriers. In this case, the slot of each CC in which there are consecutive available symbols may become a target slot of each CC. The predetermined time interval may be a value indicated or configured by the BS or a maximum delay limit based on which the UE derives.

* Method a3_2: when determining the target slots of the respective CCs, the CC having the smallest gap from the initial slot to the target slot may be selected as the target CC.

* Method a3_3: when determining the target slots of the respective CCs, a CC having the earliest starting symbol of PUCCH resources for transmitting the delayed HARQ-ACK response in the target slots of the respective CCs may be selected as the target CC.

* Method a3_4: the enabled CC may be selected as the target CC.

* Method a3_5: a CC having the same SCS as the initial CC may be selected as the target CC.

* Method a3_6: CCs having SCS greater than or equal to the initial CC may be selected as target CCs.

* Method a3_7: CCs capable of handling the same priority level as HARQ-ACK responses deferred from the initial CC may be selected as target CCs. For example, if the HARQ-ACK response delayed from the initial CC has a high priority, a CC configured with PUCCH resources of high priority may be selected as the target CC.

* Method a3_8: if two or more CCs are selected according to all considered conditions, a CC having a lowest cell index among the two or more CCs may be selected as a target CC.

Alternatively, in some implementations of the present disclosure, a method (described below) in which the UE determines a PUCCH carrier to be changed based on PUCCH carrier switching may be equally applied as a method of determining a target CC. For example, PUCCH cells of a slot may be determined according to a predetermined or predefined rule. In this case, in order to perform the HARQ-ACK deferral operation in consideration of the plurality of CCs, the UE may transmit a deferred HARQ-ACK response by applying PUCCH carrier switching to an earliest slot in which the UE can perform PUCCH transmission under the following assumption: for a given PUCCH in initial slot n (i.e., the PUCCH given for initial slot n), PUCCH carrier switching is performed for each of the following slots: time slot n, time slot n+1,..and time slot n+k. In other words, in order to support simultaneous configuration of HARQ-ACK delay and PUCCH cell handover, the UE may operate as follows. The UE may determine a next PUCCH slot on the determined PUCCH cell according to a rule predefined for PUCCH cell handover. Then, according to the HARQ-ACK deferral rule, the UE may determine whether the next PUCCH slot on the determined PUCCH cell is a target PUCCH slot for transmission. Here, the next PUCCH slot is a slot determined based on PUCCH cell switching on the determined PUCCH cell, which is mapped from a slot n+k on the initial cell to which the HARQ-ACK response is scheduled, and k increases on the initial cell.

Referring to fig. 17, assuming that an initial CC to which transmission of a HARQ-ACK response is scheduled and an initial slot are cell a and slot n, respectively, a UE may determine that cell B is a PUCCH transmission cell of slot n according to a predefined rule of PUCCH cell switching. The UE may determine whether transmission of the HARQ-ACK response is allowed in an earliest time slot (time slot m) overlapping with time slot n among the time slots on cell B. For example, the UE may determine PUCCH resources for UCI including a corresponding HARQ-ACK response in an earliest slot (slot m) overlapping with slot n among slots on cell B. The UE may then determine whether transmission of the HARQ-ACK response is allowed in slot m on cell B according to whether the PUCCH resource includes a DL symbol. If transmission of the HARQ-ACK response is not allowed in the slot m on cell B, for example, if the PUCCH resource in the slot m on cell B for the HARQ-ACK response includes a DL symbol, the UE may determine to delay transmission of the HARQ-ACK response. To determine the target slot to which the transmission of the HARQ-ACK response is deferred, the UE may determine the PUCCH cell of slot n+1 on cell a to which the transmission of the HARQ-ACK response was originally scheduled. Then, the UE may determine whether a slot m+2 mapped from the slot n+1 among slots on cell B, which is a PUCCH cell of the slot n+1, is a target slot for transmitting the deferred HARQ-ACK response. If the transmission of the deferred HARQ-ACK response is allowed in slot m+2 on cell B, the UE may transmit UCI including the deferred HARQ-ACK response on PUCCH resources in slot m+2 on cell B. If the transmission of the deferred HARQ-ACK response is not allowed in the slot m+2 on the cell B, the UE may determine whether the transmission of the deferred HARQ-ACK response is allowed in the slot n+2 on the cell a, which is the PUCCH cell of the slot n+2, and determine whether the slot n+2 on the cell a is the target slot.

When considering UL slots of respective UL CCs, slot lengths (i.e., time lengths of slots) configured for respective priorities and respective HARQ-ACK codebooks may also be considered to count UL slots. In order to simplify the operation, considering the priority indicated/configured for the source PUCCH to perform carrier switching, the UL slot applied to the target CC when the corresponding priority is used may be regarded as the UL slot of the target CC. For example, assuming that for cell a, slot lengths X and Y are used for priorities 0 and 1, respectively, and for cell B, slot lengths Y and Z are used for priorities 0 and 1, respectively, UCI on PUCCH transmission indicated as priority 1 of cell a may be transmitted via PUCCH on cell B at slot length Z if UCI on PUCCH transmission needs to be transmitted on cell B by carrier switching. In some implementations of the present disclosure, for this operation, the target CC may be restrictively selected from CCs configured with the same priority.

Since the effects obtained by the HARQ-ACK extension and the PUCCH cell switching are similar, the UE and the BS can achieve the purpose of transmitting PUCCH which cannot be transmitted due to overlapping with DL symbols in a slot initially scheduled on an initial cell to some extent even if only one of the HARQ-ACK extension and the PUCCH cell switching is performed when the HARQ-ACK extension and the PUCCH cell switching are required. However, when the UE and the BS consider the HARQ-ACK delay and the PUCCH cell switching together according to implementation A3, the UE and the BS may implement a shorter delay in PUCCH transmission than when only one of the HARQ-ACK delay and the PUCCH cell switching is performed or considered separately.

< implementation A4> maximum HARQ-ACK delay considering PUCCH carrier switching

When the UE configures a plurality of CCs and performs a HARQ-ACK deferral operation, i.e., when the UE performs BS indication/configures HARQ-ACK response transmission performed in an initial slot on an initial CC in another slot (i.e., a target slot), the UE may determine a maximum HARQ-ACK deferral range max_defer in consideration of the configured CCs. The UE may perform HARQ-ACK deferral only within the max_defer range. For example, to determine the value of max_defer, the UE may consider at least one of the following.

When the UE considers the configured set of PDSCH-to-harq_feedback timing K1 to determine max_defer, e.g., when the UE considers the configured dlDataToUL-ACK, dl-DataToUL-ACK-r16 or dl-DataToUL-ackfordcdeiformat1_2,

> UE may consider only a K1 set configured for UL CCs (e.g., primary cells) used when PUCCH carrier switching is not performed.

> UE may consider the K1 set of all candidate cells that may be subject to configured PUCCH carrier switching.

> UE may consider only the K1 set of available UL CC configurations configured for PUCCH carrier switching patterns at HARQ-ACK delay.

If the UE determines max_defer using max_defer included in each SPS PDSCH configuration, the UE may use the corresponding value without any change. The parameter max_defer in the SPS PDSCH configuration may indicate the maximum number of slots or sub-slots in which SPS HARQ-ACK transmissions may be deferred.

When the UE determines max_defer considering the configured PDSCH-to-harq_feedback timing K1 set, the UE may determine the maximum K1 value in the configured K1 set as the maximum HARQ-ACK deferral range max_defer, for example. That is, even if the HARQ-ACK deferral is performed, the HARQ-ACK deferral may be performed such that a slot position difference between the deferred HARQ-ACK PUCCH and PDSCH reception related thereto is limited to max_defer.

In order to determine the maximum K1 value or apply the determined max_defer value to UL CCs having different slot lengths (e.g., different SCS), a time length of max_defer needs to be determined. That is, when PUCCH carrier switching is used, the timing of PUCCH transmission of a timing delay received from the PDSCH may be limited by the length of time of max_defer that is actually calculated. For this purpose, at least one of the following may be considered.

An effective slot offset length obtained by applying SCS of UL CC used when PUCCH carrier switching is not performed is used as a time length of max_defer. That is, even if the UE performs HARQ-ACK extension based on PUCCH carrier switching, the HARQ-ACK extension based on PUCCH carrier switching does not exceed the maximum HARQ-ACK extension range when PUCCH carrier switching is not performed.

The length of time of > max_refer may be determined based on UL reference SCS or UL reference cell for PUCCH carrier switching pattern. The PUCCH carrier switching pattern may be predefined/preconfigured based on the UL reference SCS or UL reference cell. The BS may configure the value of max_defer of each SPS configuration based on the UL reference SCS or UL reference cell, and the UE may determine the (maximum) slot range in which HARQ-ACK deferral is allowed by interpreting the configured value of max_defer based on the UL reference SCS or UL reference cell. UL reference SCS or UL reference cell may be configured or defined to be commonly used for all SPS configurations (e.g., primary cell or Pcell may be predefined as UL reference cell). Alternatively, UL reference SCS or UL reference cells may be configured for each SPS configuration.

The length of time of > max_refer may be determined based on the maximum or minimum SCS among UL BWP configured for all candidate cells subject to PUCCH carrier switching.

The length of time of > max_transfer may be determined based on the configurable maximum or minimum SCS in the cell. For example, the length of time of max_defer may be determined based on the minimum or maximum SCS configuration u provided by SCS-specificcarrier list of the FrequencyInfoUL or FrequencyInfoUL-SIB as RRC configuration.

According to the given SCS, max_defer (number of OFDM symbols per slot) (symbol length of the given SCS) or max_defer (10 ms)/(number of slots per frame of the given SCS) can be used as the actual time length of max_defer.

When max_defer is applied under the assumption of a specific cell or a specific SCS, the deferred PUCCH transmission may overlap with the boundary of the maximum deferred range determined by max_defer. For example, in a typical single carrier operation, the boundary of the maximum deferral range, which is determined by max_defer, is aligned with the slot boundary, and thus there is no difficulty in verifying the validity of the deferral operation. In typical single carrier operation, the UE may determine the PUCCH as valid if it is deferred within the boundary of the deferred range and as invalid if it is deferred outside the boundary of the deferred range. However, in the HARQ-ACK deferral process considering PUCCH carrier switching, the boundary of the determined maximum deferral range may not be aligned with the slot boundary of the UL carrier transmitting PUCCH.

If the boundary of the maximum extension range is not aligned with the slot boundary of the UL carrier transmitting the PUCCH, the boundary of the extension range may extend into the PUCCH resource. In this case, it may be difficult to determine whether the corresponding PUCCH needs to be dropped because it is beyond the boundary of the deferred range. In some implementations of the present disclosure, the effectiveness of PUCCH discard and deferral operations may be evaluated in view of the following.

* Method a4_1: the boundary of the deferral range may be redefined based on the slot of the PUCCH carrier. For this purpose, at least one of the following methods may be considered.

* Method a4_1-1: based on the reference cell or the reference SCS used to determine the boundary of the deferred range, the UE may determine that a slot of a PUCCH carrier that overlaps in time with one or more slots in the range in which deferred operation is allowed is in the range in which deferred operation is allowed.

* Method a4_1-2: based on the reference cell or the reference SCS used to determine the boundary of the deferral range, the UE may determine that a slot of a PUCCH carrier that overlaps more than half (i.e., overlaps more than half of symbols included in the slot) in time with a slot within the range that allows deferral operation is within the range that allows deferral operation.

* Method a4_1-3: based on the reference cell or the reference SCS for determining the boundary of the deferred range, the UE may determine that the slot of the PUCCH carrier fully included in the range allowing deferred operation is in the range allowing deferred operation. In other words, the UE may assume that a slot ending just before the boundary of the deferred range is within a range that allows deferred operation.

* Method a4_2: the validity of the deferred operation may be determined based on the PUCCH resources, more specifically, by comparing the PUCCH resources to the boundary of the deferred range. For this purpose, at least one of the following methods may be considered.

* Method a4_2-1: if one or more symbols of the PUCCH resource are included in the range where deferred operation is allowed, the UE may determine that the deferred operation is valid. In other words, the UE may determine that the deferral operation is invalid only when the starting symbol of the PUCCH resource is later than the boundary of the deferral range.

* Method a4_2-2: if more than half of the symbols of the PUCCH resource are included in the range where the deferred operation is allowed, the UE may determine that the deferred operation is valid.

* Method a4_2-3: the UE may determine that the deferred operation is valid only when all symbols of the PUCCH resource are included in a range in which the deferred operation is allowed. In other words, if the last symbol of the PUCCH resource is later than the boundary of the deferral range, the UE may determine that the deferral operation is invalid.

< implementation A5> reference subcarrier spacing for PUCCH cell/carrier switching

In some implementations of the present disclosure, PUCCH cell/carrier switching may mean that the UE arbitrarily changes PUCCH cells/carriers according to a predefined rule and performs PUCCH transmission as described above. The following rules may be considered as predefined rules.

* When PUCCH radio resources are determined based on PRI included in DCI, and when DCI includes PUCCH carrier indication, PUCCH carrier switching may be performed according to the PUCCH carrier indication.

* The UE may be configured with a PUCCH carrier switching pattern through higher layer signaling from the BS. The PUCCH carrier switching pattern may refer to information listing cells to be used in a specific time unit (e.g., a slot of a given SCS configuration) within a specific time period (e.g., tens of slots, one frame, or 10 ms). If the UE performs PUCCH carrier/cell handover between two cells: the PUCCH carrier switching pattern may correspond to information listing whether the primary cell or the configured SCell will be used in each time unit of a specific time period, and the SCell configured as a target of PUCCH carrier/cell switching. The length of the time unit or slot may be determined by the UL SCS configuration configured for the cell. For example, the reference SCS configuration u_ref of the reference sub-carrier spacing provided in tdd-UL-DL-configuration Common can be used to determine the length of a time unit or time slot.

If the length of one frame is 10ms, the slot length according to each SCS configuration u can be determined according to table 1.

As described above, the reference SCS configuration provided to the UE by tdd-UL-DL-configuration command can be used to determine the slot length of the PUCCH cell/carrier switching pattern. However, since a corresponding parameter is not necessary for the UE operation, the BS may not configure the parameter for network configuration and operation. According to some implementations of the present disclosure, in case the UE does not receive higher layer parameters required to interpret the PUCCH cell/carrier switching pattern, the UE may interpret the PUCCH cell/carrier switching pattern using at least one of the following methods.

* Method a5_1: to prevent these cases, the reference SCS configuration in tdd-UL-DL-configuration command can be defined as a prerequisite for PUCCH cell/carrier switching. In other words, it may be specified that PUCCH cell/carrier switching is performed only when the reference SCS parameter in tdd-UL-DL-configuration command is configured. For example, if the reference SCS configuration in tdd-UL-DL-configuration command is not provided to the UE, the UE may not perform the PUCCH cell/carrier switching operation. Alternatively, the tdd-UL-DL-configuration common parameter set may be defined as a prerequisite element of the PUCCH cell/carrier switching capability of the UE. In other words, it may be specified that PUCCH cell/carrier switching is performed only when the UE is configured with IE tdd-UL-DL-configuration command. Thus, if the BS configures PUCCH cell/carrier switching operation for the UE, the tdd-UL-DL-configuration common parameter set may be always provided.

* Method a5_2: in preparation for the case where the tdd-UL-DL-configuration command parameter set is not provided, a separate UL reference SCS may be configured for the PUCCH carrier switching pattern. Only when the tdd-UL-DL-configuration command parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the corresponding SCS.

* Method a5_3: when the tdd-UL-DL-configuration common parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the maximum or minimum SCS among all UL BWPs configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the maximum or minimum SCS among all UL BWPs configured for the UE (in the primary cell) at all times, regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

* Method a5_4: when the tdd-UL-DL-configuration command parameter set is not provided, the slot length of the PUCCH carrier switching pattern may be determined based on a configurable maximum or minimum SCS in the primary cell. For example, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the minimum or maximum SCS configuration u provided by the sc-specificcarrier list of the freelnfo ul or freelnfo ul-SIB. Alternatively, to simplify UE operation, the slot length of the PUCCH carrier switching pattern may be determined based on the maximum or minimum SCS configurable in the primary cell at all times, regardless of whether the tdd-UL-DL-configuration common parameter set is provided to the UE.

* Method a5_5: when the tdd-UL-DL-configuration command parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on a predefined SCS value (e.g., u=0 for 15 khz). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on predefined SCS values at all times (e.g., u=0 for 15 khz), regardless of whether the tdd-UL-DL-configuration common parameter set is provided to the UE.

* Method a5_6: when the tdd-UL-DL-configuration common parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on SCS of the BWP having the lowest Identifier (ID) among all UL BWPs configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the BWP having the lowest ID among all UL BWPs configured for the UE (in the primary cell) at all times, regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

* Method a5_7: when the tdd-UL-DL-ConfigurationCommon parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on SCS of an initial UL BWP (e.g., BWP provided by RRC parameter initiallinkbwp) configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the initial UL BWP (e.g., BWP provided by RRC parameter initial uplink BWP) configured for the UE (in the primary cell) at all times, regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

* Method a5_8: when the tdd-UL-DL-ConfigurationCommon parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the first active UL BWP (e.g., BWP provided by the RRC parameter firstactionbwp-Id) configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the first active BWP (e.g., the BWP provided by the RRC parameter firstactionbwp-Id) configured for the UE at all times (in the primary cell), regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

The UE and the BS may use a plurality of the above methods simultaneously and complementarily. For example, the UE and the BS may use the methods a5_1 and a5_2 together. Specifically, when the tdd-UL-DL-configuration command parameter set is provided, the UE and the BS may use the method a5_1. The UE and BS may use the method a5_2 when the tdd-UL-DL-ConfigurationCommon parameter set is not provided.

BS side:

The above-described implementation of the present disclosure will be explained again from the perspective of the BS. The BS may provide cell configuration to UEs connected to the BS. The BS may transmit information on CCs available to the UE through cell configuration. The BS may send a MAC CE message to the UE to enable or disable the various carriers. When the BS schedules the UE to receive the PDSCH and transmit the PUCCH carrying the HARQ-ACK response thereto, the UE may dynamically select a carrier for which the UE will transmit the PUCCH carrying the HARQ-ACK response according to some implementations of the present disclosure, and the BS may receive UCI on PUCCH resources to be used on the corresponding carrier according to some implementations of the present disclosure.

In some implementations, for example, the BS may transmit scheduling information on PDSCH transmission and scheduling information on PUCCH reception of HARQ-ACK response thereto (S1801). If the UE supports HARQ-ACK extension and PUCCH cell switching, for example, if the BS configures HARQ-ACK extension and PUCCH cell switching for the UE, the BS may determine PUCCH cells and PUCCH slots that the BS will perform PUCCH reception for scheduled PDSCH transmission based on the HARQ-ACK extension and/or PUCCH cell switching according to some implementations of the present disclosure (S1803). The BS may perform PUCCH reception including HARQ-ACK information transmitted for the scheduled PDSCH in the determined PUCCH slot on the determined PUCCH cell (S1805).

The following are examples of BS operations according to some implementations of the present disclosure.

1) When the UE connects to the BS, the BS may transmit an RRC configuration including CC information (e.g., servingCellConfigCommon) to the UE through RRC signaling.

2) The BS may transmit the SPS PDSCH configuration and the RRC configuration for deferring HARQ-ACK for the SPS PDSCH to the UE through RRC signaling.

5) The BS may determine whether to change the carrier of the PUCCH to transmit for the HARQ-ACK response and/or change the indicated/configured HARQ-ACK transmission time based on some implementations of the present disclosure.

6) The BS may determine PUCCH resources to use on the changed/determined carrier and/or at the changed/determined HARQ-ACK transmission time based on some implementations of the present disclosure.

-a set of symbols in a slot indicated to the UE by the PDCCH-ConfigSIB1 in MIB of CORESET of Type0-PDCCH CSS set;

-and an effective PRACH occasionPrevious N _gap Symbol sets in the time slots corresponding to the symbols; or alternatively

The following BS operations according to some implementations of the present disclosure are mainly explained in the context of UCI reception on PUCCH, more specifically, reception of HARQ-ACK response to SPS PDSCH on PUCCH. However, the implementations of the present disclosure are applicable not only to the reception of HARQ-ACK responses for PDSCH scheduled by DCI, but also to PUSCH reception and PUCCH reception carrying other UCI.

In some implementations of the present disclosure, PUCCH carrier switching refers to the BS arbitrarily changing a PUCCH carrier according to a predefined rule and performing an operation of PUCCH reception as described above. The following rules may be considered as predefined rules.

When PUCCH radio resources are determined based on PRI included in DCI, and when DCI includes PUCCH carrier indication, BS may perform PUCCH carrier switching for UE according to the PUCCH carrier indication.

The UE may be configured with a PUCCH carrier switching pattern through higher layer signaling (e.g., RRC signaling) from the BS.

>>To indicate that the list of available UL CCs occupies a specific time unit, a time length T may be included in each list _L . Length of time T _L The time taken by the corresponding list may be meant. In this case, the period of the PUCCH carrier switching pattern may be the time length T of the available UL CC list _L Is a sum of (a) and (b). For example, there may be a specific UL CC list l1= { C1, C2, C3}, and time information T may be additionally assigned to the list L1 _L . For example, l1= { { C1, C2, C3}, T may be provided _L }. In this case, it may be at time T _L During which at least one of C1, C2 or C3 is used. These lists may be enumerated sequentially. For example, if a list is givenGiven as { L1, L2, L3,..ln }, the sum of the time lengths T of the respective lists LN may represent the length of the entire pattern.

In some implementations, information indicating that PUCCH carrier switching is not performed for a specific duration may also be included in the one or more patterns. This information can also be represented as a list of UL CCs including individual RRC parameters (e.g., nopucc hcarrierswitching). The BS may perform PUCCH reception by assuming that the UE does not perform PUCCH carrier switching for the duration indicated by the correspondence information.

When the length of one frame is 10ms, the slot length of u according to each SCS configuration can be determined according to table 1.

< implementation B1> first delays within PUCCH carrier, then carrier switching

When the BS transmits an SPS PDSCH configured/indicated for the UE and attempts to receive a HARQ-ACK response to the SPS PDSCH, if HARQ-ACK reception determined based on PUCCH resources indicated or configured for the UE and PDSCH-to-HARQ-ACK timing is not allowed due to overlap in time with one or more DL symbols, the BS may attempt to receive the HARQ-ACK response in the new target slot by assuming that the UE will first perform a HARQ-ACK deferral procedure in the initial slot to determine a new target slot for transmitting the HARQ-ACK response and then transmit the HARQ-ACK response in the corresponding slot.

In addition, the BS may receive the HARQ-ACK response by assuming that the UE will attempt PUCCH carrier switching to perform PUCCH transmission in an initial slot on another CC in the following case: when the BS is allowed to receive the HARQ-ACK response at a position far from the end of the related PDSCH transmission or from the start time of the indicated PUCCH reception than a time interval T (e.g., maximum delay limit) as a result of the HARQ-ACK delay procedure, i.e., due to the HARQ-ACK delay (e.g., when the HARQ-ACK response is allowed to be received at a later time than t_pdsch+t or t_pucch+t, where t_pdsch and t_pucch are respectively the PDSCH reception end time and the PUCCH transmission start time); when an explicit delay budget (e.g., a packet delay budget) is given for a service associated with the HARQ-ACK response transmitted by the UE and it is determined that the determined target time slot is unlikely to meet the delay budget (e.g., the packet delay budget); or when it is difficult to successfully perform the HARQ-ACK deferral procedure for other reasons.

According to implementation B1, the UE may minimize the execution of the PUCCH carrier switching operation, thereby maximizing the utilization of channel information on a single CC acquired and maintained on a corresponding CC.

< implementation B2> first carrier switch, then delay

When the BS transmits SPS PDSCH configured/indicated for the UE and attempts to receive HARQ-ACK response to the SPS PDSCH, the BS may receive PUCCH by assuming that the UE will first attempt PUCCH carrier switching in an initial slot if HARQ-ACK reception determined based on PUCCH resources indicated or configured for the UE and PDSCH-to-HARQ-ACK timing is not allowed due to overlap in time with one or more DL symbols. If the UE is expected to be unable to transmit PUCCH in the initial slot after PUCCH carrier switching, the BS may receive PUCCH from the UE in the expected target slot by assuming that the UE will perform HARQ-ACK deferral procedure.

For example, the BS may receive the HARQ-ACK response based on the following assumption: if possible, the UE will attempt HARQ-ACK PUCCH transmission in the initial slot based on PUCCH carrier switching; and if the UE is not allowed to transmit PUCCH in the initial slot despite PUCCH carrier switching (e.g., in case there are no CCs with enough UL symbols available for PUCCH transmission in the initial slot), the UE will additionally perform HARQ-ACK deferral to determine a new target slot for transmitting HARQ-ACK and then transmit HARQ-ACK response in the corresponding slot.

The BS may assume that if the UE additionally performs HARQ-ACK deferral, the UE will perform HARQ-ACK deferral based on some implementations of the present disclosure. Accordingly, the UE may perform HARQ-ACK deferral considering a plurality of CCs and minimize RTT required for PDSCH reception.

Alternatively, in order to simplify UE operation, when the BS transmits an SPS PDSCH configured/indicated for the UE and attempts to receive a HARQ-ACK response to the SPS PDSCH, if HARQ-ACK reception determined based on PUCCH resources and PDSCH-to-HARQ-ACK timing indicated or configured for the UE is not allowed due to overlapping in time with one or more DL symbols, the BS may receive the PUCCH based on the following assumption: the UE will perform PUCCH transmission by attempting PUCCH carrier switching in the initial slot; or even if PUCCH transmission is not allowed in the initial slot after PUCCH carrier switching, the UE will not perform HARQ-ACK deferral procedure. In other words, the BS may perform PUCCH reception by assuming that the UE will not perform the HARQ-ACK deferral procedure once the UE performs PUCCH carrier switching.

As another example, when PUCCH carrier switching is performed according to a PUCCH carrier switching pattern, the permission of PUCCH carrier switching in each case may be determined by the PUCCH carrier pattern. The BS may assume that the UE will not perform PUCCH carrier switching at a position indicating the initial CC on the PUCCH carrier pattern, but will perform PUCCH carrier switching at a position indicating a carrier for switching. In this case, the BS may perform PUCCH reception by assuming that the UE will perform PUCCH carrier switching at a time when PUCCH carrier switching is allowed and perform HARQ-ACK deferral procedures in a period when PUCCH carrier switching is not allowed.

< implementation B2-1> delay after carrier switch

In case of using implementation B2, when the BS transmits the SPS PDSCH configured/indicated for the UE and attempts to receive the HARQ-ACK response to the SPS PDSCH, if HARQ-ACK reception determined based on the PUCCH resources indicated or configured for the UE and the PDSCH-to-HARQ-ACK timing is not allowed due to overlapping in time with one or more DL symbols, the BS may receive the PUCCH by assuming that the UE will first attempt PUCCH carrier switching in an initial slot to transmit PUCCH.

When the BS explicitly configures the UE with a target carrier for carrier switching to be used in UL slots of the corresponding PUCCH, the BS may receive the PUCCH by assuming that if the UE cannot transmit the PUCCH in the initial slot after PUCCH carrier switching, the UE will perform HARQ-ACK deferral procedure. In this case, the following method can be considered.

* Method b2_1: the BS may perform carrier switching to a target carrier configured to be used in the initial slot and then delay PUCCH reception to a target slot on the target carrier where the BS can perform PUCCH reception. If the UL carrier configured to be used in the target slot is different from the target carrier, the BS may assume that the UE will perform PUCCH carrier switching to the target carrier again.

* Method b2_2: the BS may perform a HARQ-ACK deferral procedure on the original carrier to defer PUCCH reception to a target slot on the original carrier where the BS can perform PUCCH reception. The BS may perform PUCCH reception by assuming that the UE will perform carrier switching to a target carrier configured to be used in a target slot and then transmit PUCCH.

* Method b2_3: the BS may consider UL carriers configured to be used in respective UL slots while performing the HARQ-ACK deferral procedure as in implementation A3/B3. For example, the BS may consider the feasibility of reception on a target UL carrier of a corresponding slot (e.g., a UL slot configuring a PUCCH carrier to be used) while looking for the first UL slot of a PUCCH that the BS is able to receive a deferred. If PUCCH reception is allowed, the BS may delay PUCCH reception to a slot allowing PUCCH transmission among slots of the target UL carrier.

< implementation B3> HARQ-ACK delay and PUCCH carrier switching

When the BS configures a plurality of CCs for the UE, and when the UE performs a HARQ-ACK deferral operation, more specifically, when the BS intends to (even) receive a HARQ-ACK response received in an initial slot on an initial CC indicated/configured to the UE in another slot (i.e., a target slot), the BS may perform HARQ-ACK response reception by assuming that the UE will determine a target slot and a target CC for transmitting the HARQ-ACK response in consideration of the configured CCs. For example, when the BS is to perform BS configuration/(SPS) PDSCH transmission indicating to UEs for which the BS has configured a plurality of CCs and attempt to receive HARQ-ACK responses to the (SPS) PDSCH transmission, the BS may determine a target slot and a target CC for actually performing HARQ-ACK response reception determined based on PUCCH resources and PDSCH-to-HARQ-ACK timing indicated or configured to the UE in consideration of the configured CCs and HARQ-ACK delays. In some implementations of the present disclosure, the BS may determine a target slot and a target CC in which the UE will perform PUCCH transmission according to at least one of the following methods.

* Method b3_1: among slots within a predetermined time interval from the initial slot, CCs having consecutive available symbols (e.g., consecutive UL or flexible symbols) of PUCCH resources sufficient to transmit a HARQ-ACK response for a deferral may be selected as target PUCCH carriers. In this case, the slot of each CC in which there are consecutive available symbols may become a target slot of each CC. The predetermined time interval may be a value indicated or configured by the BS or a maximum delay limit based on which the UE derives.

* Method b3_2: when determining the target slots of the respective CCs, the CC having the smallest gap from the initial slot to the target slot may be selected as the target CC.

* Method b3_3: when determining the target slots of the respective CCs, a CC having the earliest starting symbol of PUCCH resources for transmitting the delayed HARQ-ACK response in the target slots of the respective CCs may be selected as the target CC.

* Method b3_4: the enabled CC may be selected as the target CC.

* Method b3_5: a CC having the same SCS as the initial CC may be selected as the target CC.

* Method b3_6: CCs having SCS greater than or equal to the initial CC may be selected as target CCs.

* Method b3_7: CCs capable of handling the same priority level as HARQ-ACK responses deferred from the initial CC may be selected as target CCs. For example, if the HARQ-ACK response delayed from the initial CC has a high priority, a CC configured with PUCCH resources of high priority may be selected as the target CC.

* Method b3_8: if two or more CCs are selected according to all considered conditions, a CC having a lowest cell index among the two or more CCs may be selected as a target CC.

Alternatively, in some implementations of the present disclosure, a method (described below) in which the UE determines a PUCCH carrier to be changed based on PUCCH carrier switching may be equally applied as a method of determining a target CC. For example, PUCCH cells of a slot may be determined according to a predetermined or predefined rule. In this case, in order to perform the HARQ-ACK deferral operation in consideration of the plurality of CCs, the UE may transmit a deferred HARQ-ACK response by applying PUCCH carrier switching to an earliest slot in which the UE can perform PUCCH transmission under the following assumption: for a given PUCCH in initial slot n (i.e., the PUCCH given for initial slot n), PUCCH carrier switching is performed for each of the following slots: time slot n, time slot n+1,..and time slot n+k. In other words, in order to enable the UE to support simultaneous configuration of HARQ-ACK delay and PUCCH cell handover, the BS may operate as follows. The BS may determine a next PUCCH slot on the determined PUCCH cell according to a rule predefined for PUCCH cell handover of the UE. Then, according to the HARQ-ACK deferral rule, the BS may determine whether the next PUCCH slot on the determined PUCCH cell is a target PUCCH slot for reception. Here, the next PUCCH slot is a slot determined based on PUCCH cell switching on the determined PUCCH cell, which is mapped from a slot n+k on the initial cell to which the HARQ-ACK response is scheduled, and k increases on the initial cell.

Referring to fig. 17, assuming that an initial CC and an initial slot in which a BS schedules a UE to transmit a HARQ-ACK response are cell a and slot n, respectively, the BS and the UE may determine that cell B is a PUCCH transmission cell of slot n according to a predefined rule of PUCCH cell switching. The BS may determine whether the BS can receive the HARQ-ACK response from the UE in an earliest time slot (time slot m) overlapping with time slot n among the time slots on cell B. For example, the BS may determine PUCCH resources for UCI including a corresponding HARQ-ACK response in an earliest slot (slot m) overlapping with slot n among slots on cell B. The BS may then determine whether the BS can receive the HARQ-ACK response from the UE in slot m on cell B according to whether the PUCCH resource includes the DL symbol. If the BS cannot receive the HARQ-ACK response from the UE in the slot m on cell B, for example, if the PUCCH resource in the slot m on cell B for the HARQ-ACK response includes a DL symbol, the BS may determine to delay the reception of the HARQ-ACK response. To determine the target slot to which the reception of the HARQ-ACK response is deferred, the BS may determine the PUCCH cell of slot n+1 on cell a to which the reception of the HARQ-ACK response was originally scheduled. The BS may then determine whether a slot m+2 mapped from the slot n+1 among slots on cell B, which is a PUCCH cell of the slot n+1, is a target slot for receiving the delayed HARQ-ACK response. If the reception of the deferred HARQ-ACK response is allowed in slot m+2 on cell B, the BS may receive UCI including the deferred HARQ-ACK response on PUCCH resources in slot m+2 on cell B. If the reception of the deferred HARQ-ACK response is not allowed in the slot m+2 on the cell B, for example, if the PUCCH resource for UCI including the deferred response in the slot m+2 on the cell B includes a DL symbol, the BS may determine whether the reception of the deferred HARQ-ACK response is allowed in the slot n+2 on the cell a, which is the PUCCH cell of the slot n+2, and determine whether the slot n+2 on the cell a is a target slot.

When the UE and the BS consider the HARQ-ACK delay and the PUCCH cell switching together according to implementation B3, the UE and the BS may implement a shorter delay in PUCCH transmission than when only one of the HARQ-ACK delay and the PUCCH cell switching is performed or the HARQ-ACK delay and the PUCCH cell switching are considered separately.

< implementation B4> maximum HARQ-ACK delay considering PUCCH carrier switching

When the BS configures a plurality of CCs for the UE and when the UE performs HARQ-ACK deferral operation, more specifically, when the BS intends to (even) receive in another slot (i.e., a target slot) a HARQ-ACK response that is received in an initial slot on an initial CC indicated/configured to the UE, the BS may perform HARQ-ACK response reception by assuming that the UE will determine a maximum HARQ-ACK deferral range max_defer in consideration of the configured CCs. The UE may perform HARQ-ACK deferral only within the max_defer range. For example, the BS may assume that the UE may determine the value of max_defer in consideration of at least one of the following.

When the UE determines max_defer considering the configured PDSCH-to-harq_feedback timing K1 set, the BS may assume that the UE determines, for example, the maximum K1 value in the configured K1 set as the maximum HARQ-ACK deferred range max_defer. That is, even if the HARQ-ACK deferral is performed, the HARQ-ACK deferral may be performed such that a slot position difference between the deferred HARQ-ACK PUCCH and PDSCH reception related thereto is limited to max_defer.

An effective slot offset length obtained by applying SCS of UL CC used when PUCCH carrier switching is not performed is used as a time length of max_defer. That is, the BS may assume that even though the UE performs HARQ-ACK extension based on PUCCH carrier switching, the HARQ-ACK extension based on PUCCH carrier switching does not exceed the maximum HARQ-ACK extension range when PUCCH carrier switching is not performed.

When max_defer is applied under the assumption of a specific cell or a specific SCS, the deferred PUCCH transmission may overlap with the boundary of the maximum deferred range determined by max_defer. For example, in a typical single carrier operation, the boundary of the maximum deferral range, which is determined by max_defer, is aligned with the slot boundary, and thus there is no difficulty in verifying the validity of the deferral operation. In typical single carrier operation, the BS and the UE may determine the PUCCH as valid if the PUCCH is deferred within the boundary of the deferred range and as invalid if the PUCCH is deferred outside the boundary of the deferred range. However, in the HARQ-ACK deferral process considering PUCCH carrier switching, the boundary of the determined maximum deferral range may not be aligned with the slot boundary of the UL carrier receiving PUCCH.

If the boundary of the maximum extension range is not aligned with the slot boundary of the UL carrier receiving the PUCCH, the boundary of the extension range may extend into the PUCCH resource. In this case, it may be difficult to determine whether the corresponding PUCCH needs to be dropped because it is beyond the boundary of the deferred range. In some implementations of the present disclosure, the effectiveness of PUCCH discard and deferral operations may be evaluated in view of the following.

* Method b4_1: the boundary of the deferral range may be redefined based on the slot of the PUCCH carrier. For this purpose, at least one of the following methods may be considered.

* Method b4_1-1: based on the reference cell or the reference SCS used to determine the boundary of the deferred range, the BS may determine that a slot of a PUCCH carrier that overlaps in time with one or more slots in the range in which deferred operation is allowed is in the range in which deferred operation is allowed.

* Method b4_1-2: based on the reference cell or the reference SCS used to determine the boundary of the deferral range, the BS may determine that a slot of a PUCCH carrier that overlaps more than half (i.e., overlaps more than half of symbols included in the slot) in time with a slot within the range in which deferral operation is allowed.

* Method b4_1-3: based on the reference cell or the reference SCS for determining the boundary of the deferred range, the BS may determine that the slot of the PUCCH carrier fully included in the range allowing deferred operation is in the range allowing deferred operation. In other words, the BS may assume that a slot ending just before the boundary of the deferred range is within a range that allows deferred operation.

* Method b4_2: the validity of the deferred operation may be determined based on the PUCCH resources, more specifically, by comparing the PUCCH resources to the boundary of the deferred range. For this purpose, at least one of the following methods may be considered.

* Method b4_2-1: if one or more symbols of the PUCCH resource are included in the range where deferred operation is allowed, the BS may determine that the deferred operation is valid. In other words, the BS may determine that the deferral operation is invalid only when the starting symbol of the PUCCH resource is later than the boundary of the deferral range.

* Method b4_2-2: if more than half of the symbols of the PUCCH resource are included in the range where the deferred operation is allowed, the BS may determine that the deferred operation is valid.

* Method b4_2-3: the BS may determine that the deferred operation is valid only when all symbols of the PUCCH resource are included in a range in which the deferred operation is allowed. In other words, if the last symbol of the PUCCH resource is later than the boundary of the deferral range, the BS may determine that the deferral operation is invalid.

< implementation B5> reference subcarrier spacing for PUCCH cell/carrier switching

In some implementations of the present disclosure, PUCCH cell/carrier switching may mean that the UE arbitrarily changes PUCCH cell/carrier according to a predefined rule and performs PUCCH transmission, and the BS receives a corresponding transmission from the UE on the changed PUCCH cell/carrier as described above. The following rules may be considered as predefined rules.

As described above, the reference SCS configuration provided to the UE by tdd-UL-DL-configuration command can be used to determine the slot length of the PUCCH cell/carrier switching pattern. However, since a corresponding parameter is not necessary for the UE operation, the BS may not configure the parameter for network configuration and operation. According to some implementations of the present disclosure, in case the BS does not configure higher layer parameters required to interpret the PUCCH cell/carrier switching pattern for the UE, the BS and the UE may interpret the PUCCH cell/carrier switching pattern using at least one of the following methods.

* Method b5_1: to prevent these cases, the reference SCS configuration in tdd-UL-DL-configuration command can be defined as a prerequisite for PUCCH cell/carrier switching. In other words, it may be specified that PUCCH cell/carrier switching is performed only when the reference SCS parameter in tdd-UL-DL-configuration command is configured. For example, if the BS does not provide the reference SCS configuration in tdd-UL-DL-configuration command to the UE, the BS may assume that the UE will not perform PUCCH cell/carrier switching operation. Alternatively, the tdd-UL-DL-configuration common parameter set may be defined as a prerequisite element of the PUCCH cell/carrier switching capability of the UE. In other words, it may be specified that PUCCH cell/carrier switching is performed only when the UE is configured with IE tdd-UL-DL-configuration command. Thus, if the BS configures PUCCH cell/carrier switching operation for the UE, the tdd-UL-DL-configuration common parameter set may be always provided.

* Method b5_2: in order to prepare for the case where the tdd-UL-DL-configuration command parameter set is not provided to the UE, a separate UL reference SCS may be configured for the PUCCH carrier switching pattern. Only when the tdd-UL-DL-configuration command parameter set is not provided, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the corresponding SCS.

* Method b5_3: when the tdd-UL-DL-ConfigurationCommon parameter set is not provided, the BS may assume that the UE will determine the slot length of the PUCCH cell/carrier switching pattern based on the maximum or minimum SCS among all UL BWPs configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the maximum or minimum SCS among all UL BWPs configured for the UE (in the primary cell) at all times, regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

* Method b5_4: when the tdd-UL-DL-configuration command parameter set is not provided to the UE, the slot length of the PUCCH carrier switching pattern may be determined based on a configurable maximum or minimum SCS in the primary cell. For example, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the minimum or maximum SCS configuration u provided by the sc-specificcarrier list of the freelnfo ul or freelnfo ul-SIB. Alternatively, to simplify UE operation, the slot length of the PUCCH carrier switching pattern may be determined based on the maximum or minimum SCS configurable in the primary cell at all times, regardless of whether the tdd-UL-DL-configuration common parameter set is provided to the UE.

* Method b5_5: when the tdd-UL-DL-configuration command parameter set is not provided to the UE, the slot length of the PUCCH cell/carrier switching pattern may be determined based on a predefined SCS value (e.g., u=0 for 15 khz). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on predefined SCS values at all times (e.g., u=0 for 15 khz), regardless of whether the tdd-UL-DL-configuration common parameter set is provided to the UE.

* Method b5_6: when the tdd-UL-DL-configuration common parameter set is not provided to the UE, the slot length of the PUCCH cell/carrier switching pattern may be determined based on SCS of the BWP having the lowest ID among all UL BWPs configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the BWP having the lowest ID among all UL BWPs configured for the UE (in the primary cell) at all times, regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

* Method b5_7: when the tdd-UL-DL-configuration common parameter set is not provided to the UE, the slot length of the PUCCH cell/carrier switching pattern may be determined based on SCS of an initial UL BWP (e.g., BWP provided by RRC parameter initiallinkbwp) configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the initial UL BWP (e.g., BWP provided by RRC parameter initial uplink BWP) configured for the UE (in the primary cell) at all times, regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

* Method b5_8: when the tdd-UL-DL-configuration command parameter set is not provided to the UE, the slot length of the PUCCH cell/carrier switching pattern may be determined based on SCS of the first active UL BWP (e.g., BWP provided by the RRC parameter firstactionbwp-Id) configured for the UE (in the primary cell). Alternatively, to simplify UE operation, the slot length of the PUCCH cell/carrier switching pattern may be determined based on the SCS of the first active BWP (e.g., the BWP provided by the RRC parameter firstactionbwp-Id) configured for the UE at all times (in the primary cell), regardless of whether the tdd-UL-DL-configuration command parameter set is provided to the UE.

The UE and the BS may use a plurality of the above methods simultaneously and complementarily. For example, the UE and the BS may use the methods b5_1 and b5_2 together. Specifically, when the tdd-UL-DL-configuration command parameter set is provided, the UE and the BS may use the method b5_1. The UE and BS may use the method b5_2 when the tdd-UL-DL-ConfigurationCommon parameter set is not provided.

In some implementations of the present disclosure, the BS may provide RRC configuration through a cell configuration process to configure available CCs to the UE. When the BS configures and/or instructs the UE to receive the SPS PDSCH and to transmit the PUCCH carrying the HARQ-ACK response to the SPS PDSCH, the UE may determine or change a carrier for transmitting the PUCCH carrying the HARQ-ACK response or a slot for transmitting the PUCCH according to some implementations of the present disclosure. The BS may receive UCI (including HARQ-ACK information for PDSCH) on PUCCH resources in a determined/changed slot on a determined/changed carrier according to some implementations of the disclosure.

According to some implementations of the present disclosure, when the BS and the UE are able to use multiple CCs, the BS and the UE may determine whether to perform PUCCH carrier switching and/or HARQ-ACK deferral for UL transmissions configured/indicated on unavailable resources based on the TDD configuration and the CA configuration. Alternatively, the BS and the UE may perform HARQ-ACK deferral by considering a plurality of CCs (e.g., by considering PUCCH carrier switching according to a predetermined/defined rule between the plurality of CCs). If the UE is able to communicate using multiple CCs with different TDD configurations, the BS and UE may determine/change PUCCH transmit carriers and delay HARQ-ACK responses according to some implementations of the present disclosure, allowing transmission/reception discarded due to predetermined/predefined conditions to be performed while minimizing additional delay.

The UE may perform operations in association with the transmission of HARQ-ACK information according to some implementations of the present disclosure. The UE may include: at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. The processing means for the UE may comprise: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. The computer-readable (non-volatile) storage medium may store at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations according to some implementations of the present disclosure. The computer program or computer program product may include instructions recorded on at least one computer-readable (non-volatile) storage medium and that, when executed, cause (at least one processor) to perform operations according to some implementations of the present disclosure. For a UE, a processing device, a computer-readable (non-volatile) storage medium, and/or a computer program product, operations may include: performing PDSCH reception; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for PDSCH reception and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping DL symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In some implementations, the first cell time slot n may be a time slot in which HARQ-ACK transmissions for PDSCH are scheduled.

In some implementations, multiple cells may be configured for PUCCH cell handover. Determining a PUCCH cell among the plurality of cells may include determining a PUCCH cell for the first cell slot n among the plurality of cells based on a predetermined rule of PUCCH cell handover.

In some implementations, the target slot may be an earliest slot among PUCCH cell slots determined based on a predetermined rule and the first cell slot on the first cell that is capable of performing HARQ-ACK transmission.

In some implementations, the operations may further include: based on the HARQ-ACK transmission not overlapping DL symbols in a PUCCH cell slot on a PUCCH cell for the first cell slot n, HARQ-ACK transmission is performed in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

In some implementations, determining the target time slot may include: determining a PUCCH cell for a first cell slot n+k on the first cell based on a predetermined rule, where k is a positive integer; determining a PUCCH cell for a first cell slot n+k+1 on the first cell based on the HARQ-ACK transmission overlapping with a downlink symbol in a PUCCH cell slot related to the first cell slot n+k among slots on the PUCCH cell for the first cell slot n+k; and determining whether HARQ-ACK transmission can be performed in a PUCCH cell slot related to the first cell slot n+k+1 on a PUCCH cell for the first cell slot n+k+1.

In some implementations, PDSCH reception may be semi-persistently scheduled PDSCH reception.

The BS may perform operations in association with the reception of HARQ-ACK information according to some implementations of the present disclosure. The BS may include: at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. The processing means for the BS may include: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. The computer-readable (non-volatile) storage medium may store at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations according to some implementations of the present disclosure. The computer program or computer program product may include instructions recorded on at least one computer-readable (non-volatile) storage medium and that, when executed, cause (at least one processor) to perform operations according to some implementations of the present disclosure. For a BS, a processing device, a computer readable (non-volatile) storage medium, and/or a computer program product, operations may include: performing PDSCH transmission; determining a PUCCH cell among a plurality of cells including the first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK reception for PDSCH transmission and a predetermined rule for PUCCH cell switching; determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and determining a target slot to which HARQ-ACK reception is delayed based on the HARQ-ACK reception overlapping DL symbols in a PUCCH cell slot on the PUCCH cell for the first cell slot n.

In some implementations, the target slot may be an earliest slot among PUCCH cell slots determined based on a predetermined rule and the first cell slot on the first cell that is capable of performing HARQ-ACK reception.

In some implementations, the operations may further include: based on the HARQ-ACK reception not overlapping DL symbols in a PUCCH cell slot on a PUCCH cell for the first cell slot n, HARQ-ACK reception is performed in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

In some implementations, determining the target time slot may include: determining a PUCCH cell for a first cell slot n+k on the first cell based on a predetermined rule, where k is a positive integer; determining a PUCCH cell for a first cell slot n+k+1 on the first cell based on the HARQ-ACK reception overlapping with a downlink symbol in a PUCCH cell slot related to the first cell slot n+k among slots on the PUCCH cell for the first cell slot n+k; and determining whether HARQ-ACK reception can be performed in a PUCCH cell slot related to the first cell slot n+k+1 on a PUCCH cell for the first cell slot n+k+1.

In some implementations, the PDSCH transmission may be a semi-persistently scheduled PDSCH transmission.

Examples of the disclosure as described above have been presented to enable one of ordinary skill in the art to make and practice the disclosure. Although the present disclosure has been described with reference to examples, various modifications and changes may be made by those skilled in the art in the examples of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples set forth herein but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Industrial applicability

Implementations of the present disclosure may be used in a BS, a UE, or other device in a wireless communication system.

Claims

1. A method of transmitting hybrid automatic repeat request-acknowledgement, HARQ-ACK, information by a user equipment, UE, in a wireless communication system, the method comprising the steps of:

performing physical downlink shared channel PDSCH reception;

determining a physical uplink control channel, PUCCH, cell among a plurality of cells including a first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK transmission for the PDSCH reception and a predetermined rule for PUCCH cell switching;

Determining a PUCCH cell slot related to the first cell slot n among slots on the PUCCH cell for the first cell slot n; and

determining a target slot to which the HARQ-ACK transmission is deferred based on the HARQ-ACK transmission overlapping downlink symbols in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

2. The method of claim 1, wherein the first cell slot n is a slot in which HARQ-ACK transmissions for the PDSCH reception are scheduled.

3. The method of claim 1, wherein the plurality of cells are configured for the PUCCH cell handover, and

wherein the step of determining the PUCCH cell among the plurality of cells comprises determining the PUCCH cell for the first cell slot n among the plurality of cells based on the predetermined rule for the PUCCH cell handover.

4. The method of claim 3, wherein the target slot is an earliest slot among PUCCH cell slots determined based on the predetermined rule and a first cell slot on the first cell, which can perform the HARQ-ACK transmission.

5. The method of claim 1, further comprising the step of:

the HARQ-ACK transmission is performed in the PUCCH cell slot on the PUCCH cell for the first cell slot n based on the HARQ-ACK transmission not overlapping with downlink symbols in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

6. The method of claim 1, wherein the step of determining the target time slot comprises the steps of:

determining a PUCCH cell for a first cell slot n+k on the first cell based on the predetermined rule, where k is a positive integer;

determining a PUCCH cell for a first cell slot n+k+1 on the first cell based on the HARQ-ACK transmission overlapping with downlink symbols in a PUCCH cell slot related to the first cell slot n+k among slots on the PUCCH cell for the first cell slot n+k; and

determining whether the HARQ-ACK transmission can be performed in a PUCCH cell slot related to the first cell slot n+k+1 on the PUCCH cell for the first cell slot n+k+1.

7. The method of claim 1, wherein the PDSCH reception is semi-persistently scheduled PDSCH reception.

8. A user equipment, UE, configured to transmit hybrid automatic repeat request-acknowledgement, HARQ-ACK, information in a wireless communication system, the UE comprising:

at least one transceiver;

at least one processor; and

at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations comprising:

performing physical downlink shared channel PDSCH reception;

9. A processing apparatus in a wireless communication system, the processing apparatus comprising:

at least one processor; and

performing physical downlink shared channel PDSCH reception;

determining a physical uplink control channel, PUCCH, cell among a plurality of cells including a first cell and a second cell different from the first cell based on a first cell time slot n on the first cell scheduling hybrid automatic repeat request-acknowledgement, HARQ-ACK, transmission for the PDSCH reception and a predetermined rule for physical uplink control channel, PUCCH, cell handover;

10. A computer-readable storage medium configured to store at least one program code comprising instructions that, when executed, cause at least one processor to perform operations comprising:

performing physical downlink shared channel PDSCH reception;

11. A method of receiving hybrid automatic repeat request-acknowledgement HARQ-ACK information from a user equipment UE by a base station BS in a wireless communication system, the method comprising the steps of:

Performing physical downlink shared channel PDSCH transmission;

determining a physical uplink control channel, PUCCH, cell among a plurality of cells including a first cell and a second cell different from the first cell based on a first cell slot n on the first cell scheduling HARQ-ACK reception for the PDSCH transmission and a predetermined rule for PUCCH cell switching;

a target slot to which the HARQ-ACK reception is deferred is determined based on the HARQ-ACK reception overlapping with downlink symbols in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

12. The method of claim 11, wherein the first cell slot n is a slot in which HARQ-ACK transmission for PDSCH reception is scheduled.

13. The method of claim 11, wherein the plurality of cells are configured for the PUCCH cell handover, and

14. The method of claim 13, wherein the target slot is an earliest slot among PUCCH cell slots determined based on the predetermined rule and a first cell slot on the first cell that can perform the HARQ-ACK reception.

15. The method of claim 11, further comprising the step of:

the HARQ-ACK reception is performed in the PUCCH cell slot on the PUCCH cell for the first cell slot n based on the HARQ-ACK reception not overlapping with downlink symbols in the PUCCH cell slot on the PUCCH cell for the first cell slot n.

16. The method of claim 11, wherein the step of determining the target time slot comprises the steps of:

determining a PUCCH cell for a first cell slot n+k+1 on the first cell based on the HARQ-ACK reception overlapping with downlink symbols in a PUCCH cell slot related to the first cell slot n+k among slots on the PUCCH cell for the first cell slot n+k; and

Determining whether the HARQ-ACK reception can be performed in a PUCCH cell slot related to the first cell slot n+k+1 on the PUCCH cell for the first cell slot n+k+1.

17. The method of claim 11, wherein the PDSCH transmission is a semi-persistently scheduled PDSCH transmission.

18. A base station, BS, configured to receive hybrid automatic repeat request-acknowledgement, HARQ-ACK, information from a user equipment, UE, in a wireless communication system, the BS comprising:

at least one transceiver;

at least one processor; and

performing physical downlink shared channel PDSCH transmission;