CN117941442A

CN117941442A - Method and apparatus for transmitting and receiving reference signal in wireless communication system

Info

Publication number: CN117941442A
Application number: CN202280062569.3A
Authority: CN
Inventors: 安胜振; 梁锡喆; 金善旭; 李英大
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2021-09-29
Filing date: 2022-09-15
Publication date: 2024-04-26

Abstract

A method and apparatus for transmitting or receiving a reference signal in a wireless communication system are disclosed. According to an embodiment of the present disclosure, a method of receiving a Tracking Reference Signal (TRS) in a wireless communication system by a terminal thereof includes the steps of: receiving, from the network, a control element including first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information including a field related to a TRS corresponding to each of the N cells; and receiving one or more TRSs for one or more cells among the N cells, wherein a size of the control element may be based on the N value.

Description

Method and apparatus for transmitting and receiving reference signal in wireless communication system

Technical Field

The present disclosure relates to wireless communication systems, and more particularly, to a method and apparatus for transmitting or receiving a reference signal in a wireless communication system.

Background

A mobile communication system has been developed to provide a voice service while guaranteeing mobility of a user. However, the mobile communication system has been extended to data traffic as well as voice traffic, and currently, explosive growth of traffic has resulted in resource shortage, and users have demanded faster services, and thus, more advanced mobile communication systems have been demanded.

The general need for the next generation mobile communication system should be able to support the accommodation of explosive data traffic, a significant increase in transmission rate per user, the accommodation of a significantly increased number of connected devices, very low end-to-end delay and energy efficiency. For this reason, various technologies of dual connectivity, massive multiple input multiple output (massive MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), ultra wideband support, device networking, etc. have been studied.

Disclosure of Invention

Technical problem

Technical object of the present disclosure is to provide a method and apparatus for rapidly and efficiently providing information about a Reference Signal (RS) related to cell activation for a terminal in a wireless communication system.

An additional technical object of the present disclosure is to provide a method and apparatus for quickly and efficiently performing Channel State Information (CSI) feedback related to cell activation for a terminal in a wireless communication system.

Technical objects to be achieved by the present disclosure are not limited to the above technical objects, and other technical objects not described herein will be apparent to those skilled in the art from the following description.

Technical proposal

According to an aspect of the present disclosure, a method for receiving a Tracking Reference Signal (TRS) by a terminal in a wireless communication system, includes: receiving a control element from a network, the control element comprising first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information comprising a field related to a TRS corresponding to each of the N cells; and receiving at least one TRS for at least one of the N cells, and the size of the control element is based on the value of N.

According to an additional aspect of the present disclosure, a method for transmitting a Tracking Reference Signal (TRS) by a base station in a wireless communication system, the method comprising: transmitting a control element to a terminal, the control element including first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information including a field related to a TRS corresponding to each of the N cells; and transmitting at least one TRS for at least one of the N cells to the terminal, and the size of the control element is based on the value of N.

Technical effects

In accordance with the present disclosure, a method and apparatus for rapidly and efficiently providing information about a Reference Signal (RS) related to cell activation to a terminal in a wireless communication system may be provided.

In accordance with the present disclosure, a method and apparatus for quickly and efficiently performing Channel State Information (CSI) feedback related to cell activation for a terminal in a wireless communication system may be provided.

The effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein can be clearly understood by those skilled in the art from the following description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the detailed description of the disclosure, provide examples of the disclosure and together with the detailed description describe the technical features of the disclosure.

Fig. 1 illustrates a structure of a wireless communication system to which the present disclosure can be applied.

Fig. 2 illustrates a frame structure in a wireless communication system to which the present disclosure may be applied.

Fig. 3 illustrates a resource grid in a wireless communication system to which the present disclosure may be applied.

Fig. 4 illustrates physical resource blocks in a wireless communication system to which the present disclosure may be applied.

Fig. 5 illustrates a slot structure in a wireless communication system to which the present disclosure may be applied.

Fig. 6 illustrates a physical channel used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the physical channel.

Fig. 7 is a diagram illustrating a duration of an SCell activation operation related to the present disclosure.

Fig. 8 is a diagram illustrating an example of a method for receiving a reference signal by a terminal according to the present disclosure.

Fig. 9 is a diagram illustrating an example of a method for transmitting a reference signal by a base station according to the present disclosure.

Fig. 10 is a diagram illustrating various examples of MAC CEs indicating SCell activation and TRS information according to the present disclosure.

Fig. 11 and 12 are diagrams illustrating various examples of MAC CEs indicating SCell activation, TRS information, and/or CSI reporting according to the present disclosure.

Fig. 13 illustrates an example of TRS triggering based on cross-carrier scheduling according to the present disclosure.

Fig. 14 is a diagram illustrating an example of TRS/CSI-RS related QCL assumption in a fast SCell activation procedure according to the present disclosure.

Fig. 15 is a diagram illustrating a block diagram of a wireless communication device according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description, which is disclosed by the accompanying drawings, is intended to describe exemplary embodiments of the disclosure and is not intended to represent the only embodiments in which the disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the relevant art that the present disclosure may be practiced without these specific details.

In some cases, known structures and devices may be omitted or may be shown in block diagram form based on core functions of each structure and device in order to prevent ambiguity of the concepts of the present disclosure.

In this disclosure, when an element is referred to as being "connected," "combined," or "linked" to another element, it can comprise the indirect connection and the direct connection of yet another element therebetween. Furthermore, in the present disclosure, the terms "comprises" and/or "comprising" specify the presence of stated features, steps, operations, components, and/or elements, but do not preclude the presence or addition of one or more other features, stages, operations, components, elements, and/or groups thereof.

In the present invention, terms such as "first," "second," and the like are used merely to distinguish one element from another element and are not used to limit the order or importance between the elements unless otherwise indicated. Thus, within the scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment, and as such, a second element in an embodiment may be referred to as a first element in another embodiment.

The terminology used in the present disclosure is for the purpose of describing particular embodiments, and is not intended to limit the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" as used in this disclosure may refer to one of the relevant listed items or to any and all possible combinations of two or more of them. Furthermore, unless otherwise indicated, the words "/" and/or "between words in this disclosure have the same meaning.

The present disclosure describes a wireless communication network or a wireless communication system, and operations performed in the wireless communication network may be performed in a process in which a device (e.g., a base station) controlling the corresponding wireless communication network controls the network and transmits or receives signals, or may be performed in a process in which signals are transmitted or received between a terminal associated to the corresponding wireless network and the network or terminal.

In the present disclosure, a transmission or reception channel includes a meaning of transmitting or receiving information or signals through a corresponding channel. For example, transmitting a control channel means transmitting control information or a control signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a data signal through the data channel.

Hereinafter, downlink (DL) means communication from a base station to a terminal, and Uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be part of a base station and the receiver may be part of a terminal. In the uplink, the transmitter may be part of a terminal and the receiver may be part of a base station. The base station may be expressed as a first communication device and the terminal may be expressed as a second communication device. A Base Station (BS) may be replaced with terms such as a fixed station, a node B, eNB (evolved node B), a gNB (next generation node B), a BTS (base transceiver system), an Access Point (AP), a network (5G network), an AI (artificial intelligence) system/module, an RSU (road side unit), a robot, an unmanned aerial vehicle (UAV: unmanned aerial vehicle), an AR (augmented reality) device, a VR (virtual reality) device, and the like. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (user equipment), MS (mobile station), UT (user terminal), MSs (mobile subscriber station), SS (subscriber station), AMS (advanced mobile station), WT (wireless terminal), MTC (machine type communication) device, M2M (machine to machine) device, D2D (device to device) device, vehicle, RSU (road side unit), robot, AI (artificial intelligence) module, unmanned aerial vehicle (UAV: unmanned aerial vehicle), AR (augmented reality) device, VR (virtual reality) device, and the like.

The following description may be used for various radio access systems, such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by e.g. UTRA (universal terrestrial radio access) or CDMA 2000. TDMA may be implemented by radio technologies such as GSM (global system for mobile communications)/GPRS (general packet radio service)/EDGE (data rate enhanced GSM evolution). OFDMA may be implemented by radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), and the like. UTRA is part of UMTS (universal mobile telecommunications system). The 3GPP (third Generation partnership project) LTE (Long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA, and LTE-A (advanced)/LTE-A pro is a release-advanced version of 3GPP LTE. The 3GPP NR (New radio or New radio Access technology) is an advanced release of 3GPP LTE/LTE-A/LTE-A pro.

For the sake of clarity of description, description is made based on a 3GPP communication system (e.g., LTE-A, NR), but the technical ideas of the present disclosure are not limited thereto. LTE means technology after 3GPP TS (technical specification) 36.Xxx release 8. Specifically, the LTE technology in or after 3gpp TS 36.xxx release 10 is referred to as LTE-a, and the LTE technology in or after 3gpp TS 36.xxx release 13 is referred to as LTE-a pro.3GPP NR means technology in or after TS 38.Xxx release 15. LTE/NR may be referred to as a 3GPP system. "xxx" means the detailed number of a standard file. LTE/NR may be generally referred to as a 3GPP system. For background art, terms, abbreviations, etc. used to describe the present disclosure, reference may be made to matters described in the standard documents disclosed before the present disclosure. For example, the following documents may be referred to.

For 3GPP LTE, reference may be made to TS 36.211 (physical channels and modulation), TS 36.212 (multiplexing and channel coding), TS 36.213 (physical layer procedure), TS 36.300 (general description), TS 36.331 (radio resource control).

For 3GPP NR, reference may be made to TS 38.211 (physical channel and modulation), TS 38.212 (multiplexing and channel coding), TS 38.213 (physical layer procedure for control), TS 38.214 (physical layer procedure for data), TS 38.300 (NR and NG-RAN (new generation radio access network) overall description), TS 38.331 (radio resource control protocol specification).

Abbreviations for terms that may be used in the present disclosure are defined as follows.

-BM: beam management

-CQI: channel quality indicator

-CRI: channel state information-reference signal resource indicator

-CSI: channel state information

CSI-IM: channel state information-interference measurement

-CSI-RS: channel state information-reference signal

-DMRS: demodulation reference signal

-FDM: frequency division multiplexing

-FFT: fast fourier transform

IFDMA: interleaved frequency division multiple access

-IFFT: inverse fast fourier transform

-L1-RSRP: layer 1 reference signal received power

-L1-RSRQ: layer 1 reference signal reception quality

-MAC: media access control

-NZP: non-zero power

-OFDM: orthogonal frequency division multiplexing

PDCCH: physical downlink control channel

PDSCH: physical downlink shared channel

-PMI: precoding matrix indicator

-RE: resource elements

RI: rank indicator

-RRC: radio resource control

-RSSI: received signal strength indicator

-Rx: reception of

-QCL: quasi co-placement

SINR: signal to interference noise ratio

SSB (or SS/PBCH block): synchronization signal block (including PSS (primary synchronization signal), SSS (secondary synchronization signal) and PBCH (physical broadcast channel))

-TDM: time division multiplexing

-TRP: transmitting and receiving points

-TRS: tracking reference signals

-Tx: transmitting

-UE: user equipment

-ZP: zero power

Overall system

As more communication devices require higher capacity, a need has arisen for improved mobile broadband communications compared to existing Radio Access Technologies (RATs). In addition, large-scale MTC (machine type communication) that provides various services anytime and anywhere by connecting a plurality of devices and things is also one of the main problems to be considered for next-generation communication. In addition, communication system designs that consider reliability and latency sensitive services/terminals are discussed. Thus, the introduction of next generation RATs considering eMBB (enhanced mobile broadband communications), mMTC (large-scale MTC), URLLC (ultra-reliable low-latency communications), etc. is discussed, and for convenience, the corresponding technology is referred to as NR in this disclosure. NR is an expression representing an example of a 5G RAT.

A new RAT system including NR uses an OFDM transmission method or a transmission method similar thereto. The new RAT system may follow different OFDM parameters than those of LTE. Alternatively, the new RAT system follows the parameters of the existing LTE/LTE-a as it is, but may support a wider system bandwidth (e.g., 100 MHz). Alternatively, one cell may support multiple parameter sets. In other words, terminals operating according to different parameter sets may coexist in one cell.

The parameter set corresponds to one subcarrier spacing in the frequency domain. As the reference subcarrier spacing is scaled by an integer N, different parameter sets may be defined.

Referring to fig. 1, NG-RAN is configured with a gNB providing a control plane (RRC) protocol side for NG-RA (NG radio access) user plane (i.e., new AS (access layer) sublayer/PDCP (packet data convergence protocol)/RLC (radio link control)/MAC/PHY) and UE. The gNB is interconnected by an Xn interface. Furthermore, the gNB is connected to the NGC (new generation core) through an NG interface. More specifically, the gNB is connected to an AMF (access and mobility management power) through an N2 interface, and to a UPF (user plane function) through an N3 interface.

The NR system can support multiple parameter sets. Here, the parameter set may be defined by a subcarrier spacing and a Cyclic Prefix (CP) overhead. Here, the plurality of subcarrier spacings may be derived by scaling the basic (reference) subcarrier spacing by an integer N (or μ). Furthermore, although it is assumed that a very low subcarrier spacing is not used in a very high carrier frequency, the parameter set used may be selected independently of the frequency band. Further, various frame structures according to a plurality of parameter sets may be supported in the NR system.

Hereinafter, OFDM parameter sets and frame structures that can be considered in an NR system will be described. The plurality of OFDM parameter sets supported in the NR system may be defined as table 1 below.

TABLE 1

μ	Δf＝2^μ·15[kHz]	CP
			0	15	Normal state
1	30	Normal state
			2	60	Normal, extended
3	120	Normal state
			4	240	Normal state

The NR supports a plurality of parameter sets (or subcarrier spacing (SCS)) for supporting various 5G services. For example, when SCS is 15kHz, supporting wide area of traditional cellular band; and when SCS is 30kHz/60kHz, supporting dense city, lower time delay and wider carrier bandwidth; and when SCS is 60kHz or higher, bandwidths exceeding 24.25GHz are supported to overcome phase noise.

The NR frequency band is defined as the frequency range of both types (FR 1, FR 2). FR1 and FR2 can be configured as shown in table 2 below. In addition, FR2 may mean millimeter wave (mmW).

TABLE 2

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

Regarding the frame structure in the NR system, the sizes of various fields in the time domain are expressed as multiples of T _c＝1/(Δf_max·N_f) time units. Here, Δf _max is 480·10 ³ Hz, and N _f is 4096. The downlink and uplink transmissions are configured (organized) as radio frames having a duration of T _f＝1/(Δf_maxN_f/100)·T_c =10 ms. Here, the radio frame is configured with 10 subframes each having a duration of T _sf＝(Δf_maxN_f/1000)·T_c =1 ms. In this case, there may be one frame set for the uplink and one frame set for the downlink. Furthermore, transmission in the i-th uplink frame from the terminal should start earlier than the corresponding downlink frame in the corresponding terminal by T _TA＝(N_TA+N_TA,offset)T_c. For a subcarrier spacing configuration μ, the slots are numbered in ascending order of n _s ^μ∈{0,...,N_slot ^subframe,μ -1 in the subframe and in ascending order of n _s,f ^μ∈{0,...,N_slot ^frame,μ -1 in the radio frame. One slot is configured with N _symb ^slot consecutive OFDM symbols, and N _symb ^slot is determined according to the CP. The beginning of slot n _s ^μ in a subframe is aligned in time with the beginning of OFDM symbol n _s ^μN_symb ^slot in the same subframe. All terminals may not perform transmission and reception at the same time, which means that all OFDM symbols of a downlink slot or an uplink slot may not be used.

Table 3 shows the number of OFDM symbols per slot (N _symb ^slot), the number of slots per radio frame (N _slot ^frame,μ), and the number of slots per subframe (N _slot ^subframe,μ) in the normal CP, and table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

TABLE 3

μ	N_symb ^slot	N_slot ^frame,μ	N_slot ^subframe,μ
				0	14	10	1
1	14	20	2
				2	14	40	4
3	14	80	8
				4	14	160	16

TABLE 4

μ	N_symb ^slot	N_slot ^frame,μ	N_slot ^subframe,μ
				2	12	40	4

Fig. 2 is an example of μ=2 (SCS is 60 kHz), and referring to table 3,1 subframe may include 4 slots. The 1 subframe= {1,2,4} slot as shown in fig. 2 is an example, and the number of slots that can be included in the 1 subframe is defined as in table 3 or table 4. In addition, the micro slot may include 2,4, or 7 symbols or more or less.

Regarding physical resources in the NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. may be considered. Hereinafter, physical resources that can be considered in the NR system will be described in detail.

First, with respect to antenna ports, antenna ports are defined such that channels carrying symbols in an antenna port can be inferred from channels carrying other symbols in the same antenna port. When the massive nature of the channel in which the symbols in one antenna port are carried can be inferred from the channel carrying the symbols of another antenna port, it can be said that 2 antenna ports are in QC/QCL (quasi co-located or quasi co-located) relationship. In this case, the large-scale property includes at least one of delay spread, doppler spread, frequency shift, average received power, and reception timing.

Referring to fig. 3, it is illustratively described that a resource grid is configured with N _RB ^μN_sc ^RB subcarriers in a frequency domain and one subframe is configured with 14·2 ^μ OFDM symbols, but is not limited thereto. In an NR system, a transmitted signal is described by 2 ^μN_symb ^(μ) OFDM symbols and one or more resource grids configured with N _RB ^μN_sc ^RB subcarriers. Here, N _RB ^μ≤N_RB ^max,μ.N_RB ^max,μ denotes a maximum transmission bandwidth, which may be different between uplink and downlink and between parameter sets. In this case, one resource grid may be configured per mu and antenna port p. Each element of the resource grid for μ and antenna port p is called a resource element and is uniquely identified by an index pair (k, l'). Here, k=0,..n _RB ^μN_sc ^RB -1 is an index in the frequency domain, and l' =0,..2 ^μN_symb ^(μ) -1 refers to a symbol position in a subframe. When referencing a resource element in a slot, an index pair (k, l) is used. Here, l=0,..n _symb ^μ -1. The resource elements (k, l') for μ and antenna port p correspond to complex values a _k,l' ^(p,μ). When there is no risk of confusion or when no particular antenna port or parameter set is specified, the indices p and μmay be discarded, and the complex value may then be a _k,l' ^(p) or a _k,l'. Further, a Resource Block (RB) is defined to N _sc ^RB =12 consecutive subcarriers in the frequency domain.

Point a functions as a common reference point for the resource block grid and is obtained as follows.

-OffsetToPointA of the primary cell (PCell) downlink represents the frequency offset between point a and the lowest subcarrier of the lowest resource block overlapping with the SS/PBCH block used by the terminal for initial cell selection. It is expressed in units of resource blocks assuming that a subcarrier spacing of 15kHz is used for FR1 and a subcarrier spacing of 60kHz is used for FR 2.

-AbsoluteFrequencyPointA denotes the frequency position of point a, expressed in ARFCN (absolute radio frequency channel number).

For a subcarrier spacing configuration μ, the common resource blocks are numbered from 0 up in the frequency domain. The center of subcarrier 0 of common resource block 0 for subcarrier spacing configuration μ is the same as in "point a". The relationship between the common resource block number n _CRB ^μ of the subcarrier spacing configuration μ in the frequency domain and the resource elements (k, l) is given as the following equation 1.

[ Equation 1]

In equation 1, k is defined with respect to point a such that k=0 corresponds to a subcarrier centered on point a. The physical resource blocks are numbered from 0 to N _BWP,i ^size,μ -1 in the bandwidth part (BWP), and i is the number of BWP. The relationship between the physical resource block n _PRB and the common resource block n _CRB in BWP i is given by the following equation 2.

[ Equation 2]

N _BWP,i ^start,μ is the common resource block from which BWP starts with respect to common resource block 0.

Fig. 4 illustrates physical resource blocks in a wireless communication system to which the present disclosure may be applied. Also, fig. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

Referring to fig. 4 and 5, a slot includes a plurality of symbols in the time domain. For example, for a normal CP,1 slot includes 7 symbols, but for an extended CP,1 slot includes 6 symbols.

The carrier comprises a plurality of subcarriers in the frequency domain. An RB (resource block) is defined to be a plurality (e.g., 12) of consecutive subcarriers in the frequency domain. BWP (bandwidth part) is defined as a plurality of consecutive (physical) resource blocks in the frequency domain and may correspond to one parameter set (e.g., SCS, CP length, etc.). The carrier may include a maximum of N (e.g., 5) BWPs. Data communication may be performed through the activated BWP, and only one BWP may be activated for one terminal. In a resource grid, each element is referred to as a Resource Element (RE) and may map one complex symbol.

In an NR system, each Component Carrier (CC) may support up to 400MHz. If a terminal operating in such a wideband CC is always operating with a radio Frequency (FR) chip for the entire CC turned on, terminal battery consumption may increase. Alternatively, when considering multiple application scenarios (e.g., eMBB, URLLC, mmtc, V X, etc.) operating in one wideband CC, different parameter sets (e.g., subcarrier spacing, etc.) may be supported in each frequency band in the corresponding CC. Alternatively, each terminal may have different capabilities for maximum bandwidth. In view of this, the base station may instruct the terminal to operate in only a partial bandwidth, not in the full bandwidth of the wideband CC, and for convenience, the corresponding partial bandwidth is defined as a bandwidth part (BWP). BWP may be configured with consecutive RBs on the frequency axis and may correspond to one parameter set (e.g., subcarrier spacing, CP length, time slot/micro-slot duration).

Meanwhile, the base station may configure a plurality of BWP even in one CC configured for the terminal. For example, BWP occupying a relatively small frequency domain may be configured in a PDCCH monitoring slot, and PDSCH indicated by PDCCH may be scheduled in a larger BWP. Alternatively, when the UE is congested in a specific BWP, some terminals may be configured with other BWPs for load balancing. Alternatively, some full-bandwidth intermediate spectrum may be excluded in consideration of frequency domain inter-cell interference cancellation between neighboring cells, etc., and BWP on both edges may be configured in the same slot. In other words, the base station may configure at least one DL/UL BWP to a terminal associated with the wideband CC. The base station may activate at least one DL/UL BWP of the configured DL/UL BWP at a specific time (through L1 signaling or MAC CE (control element) or RRC signaling, etc.). Further, the base station may instruct (through L1 signaling or MAC CE or RRC signaling, etc.) to switch to other configured DL/UL BWP. Alternatively, based on a timer, when the timer value expires, a switch may be made to the determined DL/UL BWP. Here, the activated DL/UL BWP is defined as an active DL/UL BWP. But may not receive the configuration regarding DL/UL BWP when the terminal performs the initial access procedure or before setting up the RRC connection, and thus the DL/UL BWP assumed by the terminal in these cases is defined as an initially active DL/UL BWP.

Fig. 6 illustrates a physical channel used in a wireless communication system to which the present disclosure can be applied and general signal transmission and reception methods using the physical channel.

In a wireless communication system, a terminal receives information from a base station through a downlink and transmits information to the base station through an uplink. The information transmitted and received by the base station and the terminal includes data and various control information, and there are various physical channels according to the type/purpose of the information they transmit and receive.

When the terminal is turned on or newly enters a cell, it performs an initial cell search including synchronization with a base station, etc. (S601). For initial cell search, a terminal may synchronize with a base station by receiving a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station and obtain information such as a cell Identifier (ID). The terminal may then acquire broadcast information in the cell by receiving a Physical Broadcast Channel (PBCH) from the base station. Meanwhile, the terminal may check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search phase.

The terminal that completed the initial cell search may obtain more detailed system information by receiving a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH) according to information carried in the PDCCH (S602).

Meanwhile, when the terminal accesses the base station for the first time or does not have radio resources for signal transmission, it may perform a Random Access (RACH) procedure on the base station (S603 to S606). For the random access procedure, the terminal may transmit a specific sequence as a preamble through a Physical Random Access Channel (PRACH) (S603 and S605), and may receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S604 and S606). The contention-based RACH may additionally perform a contention resolution procedure.

The terminal that then performs the above procedure may perform PDCCH/PDSCH reception (S607) and PUSCH (physical uplink shared channel)/PUCCH (physical uplink control channel) transmission (S608) as a general uplink/downlink signal transmission procedure. Specifically, the terminal receives Downlink Control Information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for a terminal, and a format varies according to its purpose of use.

Meanwhile, control information transmitted by the terminal to the base station through the uplink or received by the terminal from the base station includes downlink/uplink ACK/NACK (acknowledgement/non-acknowledgement) signals, CQI (channel quality indicator), PMI (precoding matrix indicator), RI (rank indicator), and the like. For the 3GPP LTE system, the terminal can transmit the control information of CQI/PMI/RI and the like through PUSCH and/or PUCCH.

Table 5 shows an example of DCI formats in an NR system.

TABLE 5

Referring to table 5, DCI formats 0_0, 0_1, and 0_2 may include resource information (e.g., UL/SUL (supplemental UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), information related to Transport Blocks (TBs) (e.g., MCS (modulation and coding scheme), NDI (new data indicator), RV (redundancy version), etc.), information related to HARQ (hybrid-automatic repeat and request) (e.g., procedure number, DAI (downlink assignment index), PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., DMRS sequence initialization information, antenna ports, CSI requests, etc.), power control information related to scheduling of PUSCH (e.g., PUSCH power control, etc.), and control information included in each DCI format may be predefined.

DCI format 0_0 is used to schedule PUSCH in one cell. The information included in the DCI format 0_0 is CRC (cyclic redundancy check) scrambled and transmitted through a C-RNTI (cell radio network temporary identifier) or CS-RNTI (configured scheduling RNTI) or MCS-C-RNTI (modulation coding scheme cell RNTI).

DCI format 0_1 is used to indicate scheduling or Configuration Grant (CG) downlink feedback information of one or more PUSCHs to a terminal in one cell. The information included in the DCI format 0_1 is CRC-scrambled and transmitted through a C-RNTI or CS-RNTI or SP-CSI-RNTI (semi-persistent CSI RNTI) or MCS-C-RNTI.

DCI format 0_2 is used to schedule PUSCH in one cell. The information included in the DCI format 0_2 is CRC-scrambled and transmitted through the C-RNTI or the CS-RNTI or the SP-CSI-RNTI or the MCS-C-RNTI.

Next, DCI formats 1_0, 1_1, and 1_2 may include resource information (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block) -PRB (physical resource block) mapping, etc.), transport Block (TB) -related information (e.g., MCS, NDI, RV, etc.), HARQ-related information (e.g., a process number, DAI, PDSCH-HARQ feedback timing, etc.), multiple antenna-related information (e.g., antenna ports, TCI (transmission configuration indicator), SRS (sounding reference signal) request, etc.), PUCCH-related information (e.g., PUCCH power control, PUCCH resource indicator, etc.) regarding scheduling of PDSCH, and control information included in each DCI format may be predefined.

DCI format 1_0 is used to schedule PDSCH in one DL cell. The information included in the DCI format 1_0 is CRC-scrambled by the C-RNTI or the CS-RNTI or the MCS-C-RNTI and transmitted.

DCI format 1_1 is used to schedule PDSCH in one cell. The information included in the DCI format 1_1 is CRC-scrambled by the C-RNTI or the CS-RNTI or the MCS-C-RNTI and transmitted.

DCI format 1_2 is used to schedule PDSCH in one cell. The information contained in the DCI format 1_2 is CRC-scrambled by the C-RNTI or CS-RNTI or MCS-C-RNTI and transmitted.

Carrier aggregation

The wireless communication system may support Carrier Aggregation (CA). For example, a 3GPP LTE or NR system can support a wider uplink/downlink (UL/DL) bandwidth by aggregating multiple UL/DL Component Carriers (CCs). Each CC may or may not be adjacent to each other in the frequency domain. The bandwidth of each CC may be determined independently. Asymmetric carrier aggregation in which the number of UL CCs and the number of DL CCs are different is also possible.

When carrier aggregation is applied, a specific one CC supporting basic operation may be referred to as a primary CC (PCC), and at least one additional CC may be referred to as a secondary CC (SCC). For one CC, only UL may be configured, only DL may be configured, or UL and DL may be configured.

A control channel (e.g., PDCCH) including scheduling information for transmission and reception of UL/DL data channels (e.g., PUSCH/PDSCH) in a specific CC may be transmitted in the corresponding specific CC. Such operations may be referred to as self-carrier scheduling (or simply self-scheduling) to distinguish such operations from cross-carrier scheduling (CCS) (or simply cross-scheduling), as will be described below.

When Cross Carrier Scheduling (CCS) or cross scheduling is applied, for example, a PDCCH for downlink allocation may be transmitted on DL CC #0 and a corresponding PDSCH may be transmitted on DL CC # 2. For CCS, a Carrier Indicator Field (CIF) may be used. The configuration in the PDCCH (or DCI) for the presence or absence of CIF may be semi-statically enabled or disabled by terminal-specific (or terminal group-specific) higher layer signaling (e.g., RRC signaling).

When CIF is disabled, PDCCH on DL CC may allocate PDSCH resources on the same DL CC or PUSCH resources on one UL CC linked to the same DL CC. In this case, the CIF may not be included in the DCI.

When CIF is enabled, PDCCH on DL CC may allocate PDSCH or PUSCH resources on one DL/UL CC indicated by CIF among multiple aggregated DL/UL CCs. In a DCI format including CIF, a CIF field having a size of x bits (e.g., x=3) may have a fixed position in the DCI regardless of the DCI format size.

When CIF is present/applied, the base station may allocate a monitoring DL CC (or set of DL CCs) to reduce PDCCH Blind Decoding (BD) complexity at the terminal side. For PDSCH/PUSCH scheduling, the terminal may perform detection/decoding of PDCCH only in the corresponding DL CC(s). In addition, the base station may transmit the PDCCH by monitoring only DL CCs (sets). The monitored DL CC set can be configured in a terminal-specific, terminal group-specific or cell-specific manner.

For example, assume that three DL CCs are aggregated and DL CC a is configured as a PDCCH monitoring CC. When CIF is disabled, each DL CC may transmit only PDCCH scheduling its own PDSCH (i.e., self-carrier scheduling). When CIF is enabled through terminal-specific (or terminal group-specific or cell-specific) higher layer signaling, a specific CC (e.g., DL CC a) may use CIF to transmit PDCCH scheduling PDSCH of another DL CC and PDCCH scheduling PDSCH of DL CC a (i.e., cross-carrier scheduling). The PDCCH may not be transmitted in DL CCs B and C.

The definition of terms related to cells in the present invention is as follows. In the present disclosure, a cell may be interpreted according to the context and may mean, for example, a serving cell. In addition, a cell may be composed of one DL CC and 0 to 2 UL CCs. For example, a cell may be composed of one DL CC and one UL CC.

For terminals in which Carrier Aggregation (CA) is configured, the primary cell (PCell) corresponds to a cell operating on a primary frequency, i.e., a frequency in which the terminal performs setup/re-establishment for initial access, and for Dual Connectivity (DC) operation, a cell operating on a primary frequency among a set of primary cells (MCG) corresponds to the primary cell.

For terminals in which Carrier Aggregation (CA) is configured, the secondary cell (SCell) corresponds to a cell that provides additional radio resources to the SpCell.

For DC operation, a primary secondary cell (PSCell) (or primary SCG cell) corresponds to a cell in which a terminal performs random access when the terminal performs a reconfiguration and synchronization procedure in a Secondary Cell Group (SCG).

For DC operation, the special cell (SpCell) refers to the PCell of the MCG or the PSCell of the SCG. For non-DC operation, spCell refers to PCell.

For terminals in the rrc_connected state in which CA/DC is not configured, there is only one serving cell (ServCell), and the corresponding cell corresponds to the primary cell. For terminals in rrc_connected state in which CA/DC is configured, the serving cell refers to a set of cells including SpCell and all scells.

The addition/change of the list of scells may be configured for the terminal by higher layer (e.g., RRC) signaling. Thus, one or more scells may be configured for a terminal. Based on the one or more scells configured for the terminal, the network may indicate activation/deactivation of the configured scells (deactivation). The SCell activation/deactivation of the terminal may be performed based on the SCell activation/deactivation MAC CE, a predetermined timer, or an indication of SCell status provided with the SCell configuration.

Enhanced SCell activation

As described above, in order to perform large-capacity data transmission/reception by using an extended bandwidth through a new CA/DC-based SCell, the SCell needs to be configured (e.g., added/changed) for a terminal first, and thereafter, an activated procedure related to the configured SCell is performed.

Immediately after the SCell is activated, data scheduling and data transmission/reception (e.g., PDSCH/PUSCH scheduling and PDSCH/PUSCH transmission/reception through DCI) may not be performed between the network and the terminal on the corresponding SCell. For example, synchronization and tracking may need to be performed to minimize errors prior to data transmission/reception on an activated SCell. For example, the terminal may perform fine tracking based on a predetermined Reference Signal (RS) after receiving the SSB. Further, the terminal may send feedback (e.g., CSI reports) to the network based on the RSs from the network.

The present disclosure describes various examples for supporting/performing faster SCell activation. For example, the present disclosure includes: embodiment 1 related to a method for allowing a terminal to quickly receive an RS for tracking purposes (in the following description, a temporary RS for tracking purposes is referred to as a "TRS"), embodiment 2 related to a method for quickly reporting feedback on a downlink channel state, embodiment 3 related to a method for reducing time of an overall procedure from SCell activation to CSI feedback, and embodiment 4 related to a method for effectively applying QCL information of a TRS.

In fig. 7, the horizontal axis corresponds to time, and a point of time when the SCell activation indication/command is received (or a point of time when the base station transmits the SCell activation indication/command) may be referred to as t ₀. Specifically, activation for a specific SCell may be signaled/indicated by a MAC CE for the specific SCell transmitted in the PCell (or another SCell that has been activated).

For the PDSCH including the MAC CE, the terminal may transmit HARQ-ACK information to the network. The point in time at which the HARQ-ACK information is transmitted by the terminal (or the point in time at which the HARQ-ACK information is received by the base station) may be referred to as t ₁. For example, the HARQ-ACK information may include ACK information for PDSCH decoding success and NACK information for failure. The length (or duration) of the portion of time required for the terminal to receive the PDSCH, attempt to decode it, and transmit HARQ-ACK information may be referred to as T _HARQ.

Next, the terminal may prepare to perform transmission/reception on the corresponding SCell based on the information indicated by the SCell activation MAC CE. The point in time at which transmission/reception preparation is completed on the SCell to be activated may be referred to as t ₂. For example, the terminal may perform synchronization through SSB reception on the activated SCell, preparation of CSI-RS reception with frequency configuration, automatic Gain Control (AGC) preparation, and the like, and thus the length of its time portion may be referred to as T _{activation_time}.

Finally, the terminal may perform CSI reporting. CSI reporting of the terminal may not be necessary. The transmission time point at which CSI reports are made by the terminal (or the reception time point at which CSI reports are made by the base station) may be referred to as t ₃. For example, the terminal may transmit CSI reports in the uplink by performing CSI-RS measurements, channel estimation, CSI calculation, and the like. The length of the time portion for performing the above may be referred to as T _{CSI_Reporting}.

Thus, the total length of time from when the terminal receives the SCell activation indication and first transmits the CSI report may be T _HARQ+T_{activate_time}+T_{CSI_Reporting}.

The present disclosure generally describes methods for efficiently signaling/indicating various information, such as RS-related information, to a terminal for reducing the length of the T _{activation_time} duration and/or reducing the length of the T _{CSI_Reporting} duration.

Fig. 8 is a diagram illustrating an example of a method for receiving a reference signal of a terminal according to the present disclosure.

In step S810, the terminal may receive a control element indicating cell activation from the base station.

The control element may include first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated. For example, among M (M is an integer greater than or equal to N) cells (e.g., scells) configured for a terminal (e.g., added/changed through higher layer signaling), activation of N cells may be indicated. That is, the control element may indicate that the cell (or SCell) corresponding to the indicated identifier/index is activated by including information about the cell identifier (or cell index) for each of the N cells.

The control element may further include a field related to a TRS (hereinafter, a TRS related field) corresponding to each of the N cells. The number of TRS related fields may be equal to N, which is the number of cells for which activation is indicated. That is, one TRS related field may correspond to one cell for which activation is indicated.

The TRS related field may indicate an identifier of the TRS. For example, an identifier of the TRS may indicate a configuration of the TRS (i.e., CSI-RS for tracking purposes). One or more CSI-RS configurations (e.g., pre-configured by higher layer signaling) may be provided to the terminal, and where a particular CSI-RS configuration may be pre-configured for tracking purposes related to cell activation. The TRS configuration provided in this manner (i.e., corresponding to the CSI-RS configuration) may include various configuration parameters such as CSI-RS/TRS resources, periodicity, offset, and QCL information. That is, the TRS configuration may be specified by an identifier of the TRS.

The TRS related field may indicate a TRS identifier for the cell for which activation is indicated or may indicate that TRS is not used. A cell for which TRS is not used to be indicated for activation may mean that the TRS is not triggered or that the TRS is not configured. The indication that the TRS is not used may include a TRS related field indicating a 0 (zero) value or a null state.

As such, a control element indicating cell activation may be generated/provided/received/processed in the form of MAC CE through the MAC layer based on a configuration for a cell (e.g., SCell addition/change configuration) signaled by a higher layer (e.g., RRC), or a configuration for a TRS (e.g., CSI-RS configuration, or CSI-RS configuration configured for the purpose of a TRS related to cell activation).

In step S820, the terminal may receive TRSs for one or more cells.

Here, the one or more cells may be some or all of the N cells for which activation is indicated. That is, among cells for which activation is indicated, a TRS indication or trigger may be applied to a certain cell, and a TRS indication or trigger may not be applied to other cells.

The terminal can receive TRSs for one or more cells in an aperiodic manner, and information required for the reception of the TRSs can be based on CSI-RS/TRS configuration indicated by a TRS-related field.

Fig. 9 is a diagram illustrating an example of a reference signal transmission method of a base station according to the present disclosure.

In step S910, the base station may transmit a control element indicating cell activation to the terminal.

Here, the description related to the control element indicating the cell activation is the same as that described with reference to step S810 of fig. 8, and redundant description will be omitted.

In step S920, the base station may transmit a TRS for one or more cells to the terminal.

The description about one or more cells and the configuration for TRS transmission or reception are the same as those described with reference to step S820 of fig. 8, and redundant description will be omitted.

A detailed example of the reference signal transmission/reception method for fast cell activation described with reference to fig. 8 and 9 will be described hereinafter. In addition, although not shown in fig. 8 and 9, CSI report transmission/reception related to cell activation may be additionally performed, and detailed examples thereof will be described below.

Example 1

The present embodiment relates to a method in which a terminal rapidly receives a TRS or a base station supports the same TRS. For example, a method for quickly and efficiently performing activation of an SCell configured for a terminal and preparation for reception on the SCell will be described.

The terminal may receive an activation command for an (non-activated) SCell through a MAC CE in the PCell (or any already activated SCell). For the SCell indicated by the activation command, the terminal may prepare for reception from the beginning of the T _{activation_time} duration (i.e., T ₁ in fig. 7). Here, the preparation for reception may include the terminal preparing to correctly perform reception and decoding of a physical channel (e.g., PDCCH or PDSCH) including information transmitted from the base station by using reception-related information (e.g., SSB, frequency, CSI-RS resource, etc.) included in the RRC configuration message related to SCell addition/change. For example, the T _{activation_time} duration may include a time for performing synchronization of the terminal with the base station based on SSB, AGC, frequency synchronization, preparation for reception and measurement of a channel, and the like, and additionally include a predetermined offset corresponding to a processing time for transition of a previous operation and a next operation, and the like.

In order to shorten the duration of this part, a method for allowing the terminal to quickly perform measurement on channel reception may be considered. For example, by triggering a reference signal (e.g., TRS) such as CSI-RS resources with an SCell activation command in a terminal-specific (or terminal-specific) manner, the terminal may perform fast and accurate time tuning and receive channel analysis by the reference signal. For example, the TRS may be transmitted aperiodically or via at least one burst. One burst may correspond to a unit in which one or more transmissions (e.g., 2-4 transmissions) are performed during a predetermined duration. In addition, the terminal may perform CSI reporting based on the TRS, and the CSI reporting time may be advanced as much as the TRS trigger is performed at an earlier time.

Specific details of TRS triggering will be described below. For example, trigger information for TRS transmissions may be provided/indicated for each SCell for which activation is indicated. The signaling/indication scheme for this may be defined by a combination of one or more of the following examples a-G.

Example a. A set of parameters (e.g., RS transmission resources, QCL related information, etc.) for a plurality of (candidate) TRSs is configured in advance for each SCell through RRC signaling.

Example b. with respect to activated scells (except deactivated scells), whether to transmit TRS for each cell and RS parameter information may be sequentially indicated according to a cell index order. Here, the individual cell index indication information for the SCell that is the target of the TRS trigger may be omitted.

Example c.trs trigger information and information indicating SCell activation may be included in the same single MAC CE or included in separate MAC CEs but may be transmitted through the same PDSCH. When included in a separate MAC CE, it is possible to sequentially indicate whether or not to transmit TRSs for each cell and RS parameter information according to a cell index order by triggering the MAC CE by the TRSs only for scells for which activation is indicated by the SCell activation MAC CE (except for scells for which deactivation is indicated). Here, the individual cell index indication information for the SCell that is the target of the TRS trigger on the RS triggering the MAC CE may be omitted.

Example d.trs transmission timing information (e.g., trigger offset, trigger slot offset, etc.) may be indicated as common timing for all scells for which TRS is triggered, or may be indicated separately for each SCell (or TRS). When separate timing information is indicated for each SCell (or TRS), the corresponding timing information may be included in an RS parameter set configured in advance through RRC signaling.

Example f. For an indication of TRS trigger information, one or more bit-sized fields/information may be defined. For example, when each cell is allocated 3 bits of information, the TRS trigger information may indicate one of eight states. For example, each of the eight states may indicate a TRS identifier or may indicate no TRS (e.g., null or 0). For example, the 8 states may include { no TRS, RS ID #a1, RS ID #a2, RS ID #a3, RS ID #a4, RS ID #a5, RS ID #a6, RS ID #a7}. When 4 TRS IDs from 1 to 4 are configured for the corresponding SCell, they are mapped as a1=1, a2=2, a3=3, a4=4 (in this case, TRSs corresponding to RS ID #a5/a6/a7 do not exist), and when 1 to 10 are configured, the lowest 7 indexes among them may be mapped to a1-a7. Alternatively, each mapping information such as an ID corresponding to a1 and an ID corresponding to a2 may be preconfigured through RRC signaling. In addition, reserved bits may be added to match an octet unit (octet unit). In various examples to be described below, the size of the reserved bits R may be 1 bit to 7 bits.

Example g. existing MAC CEs for SCell activation/deactivation indication may be referred to as (legacy) SCell activation/deactivation MAC CEs, and MAC CEs proposed in the present disclosure including TRS information/fields may be referred to as names (e.g., enhanced SCell activation/deactivation MAC CEs) different from (legacy) SCell activation/deactivation MAC CEs. For example, a terminal supporting 3GPP Standard Release 17 (R-17) can apply legacy MAC CEs and enhanced MAC CEs separately, or can follow enhanced MAC CEs.

Fig. 10 is a diagram illustrating various examples of MAC CEs indicating SCell activation and TRS information according to the present disclosure. An example will be described below with reference to fig. 10.

Example 1-1

The present embodiment relates to a method of defining a new MAC CE and simultaneously providing information related to SCell activation and TRS triggering on a single message.

The example of fig. 10 (a) corresponds to an example of the MAC CE configuration according to the present embodiment.

For example, for each SCell, a MAC CE including Y-bit information indicating an SCell index (or ID) and Z-bit information indicating a TRS ID (or index) may be defined.

The Z-bit information may indicate which of a plurality of TRS IDs is transmitted or no TRS is transmitted. The particular state indicating that the TRS is not transmitted may correspond to "no TRS trigger", null, or 0 (zero).

The sum of Y and Z bits may be configured to 8 bits or less. One octet including Y bit information and/or Z bit information may be allocated/mapped for each SCell.

Information about different scells may be allocated/mapped separately to different octets.

For such MAC CEs, a new MAC Logical Channel ID (LCID) field value different from the existing MAC CE may be applied.

The MAC CE may include a field for an SCell index (or ID) in which an indicated SCell is activated, and a field for an ID (or index) indicating a TRS (resource) triggered for a corresponding SCell among CSI-RS resources (e.g., candidate RRC resource related list of TRSs) preconfigured by RRC. The location of each RS, the number of transmissions, the transmission time, QCL related information, etc. may be included in a TRS list provided when scells are added/changed in RRC. In the example of fig. 10 (a), one octet may be configured to include 4 bits of activation information and 3 bits of TRS information for one SCell. In the example of fig. 10 (a), bits corresponding to C ₀ may be reserved.

In case of multiple SCell activation, multiple octets may be included in the MAC CE. One octet may include one SCell ID and a TRS ID triggered for the corresponding SCell. The number of octets included in one MAC CE may be variable according to the number of scells for which activation is indicated simultaneously.

The example of fig. 10 (b) corresponds to a modified example of the MAC CE configuration.

For example, for each SCell, a MAC CE including X-bit information indicating whether a TRS is triggered (or on-off), Y-bit information indicating an SCell index (or ID), and Z-bit information indicating a TRS ID (or index) may be defined.

The X-bit information may indicate whether the TRS is transmitted, and the Z-bit information may indicate which of a plurality of TRS IDs is transmitted. For example, the X bit may be defined as a1 bit and may indicate that the TRS is triggered if its value is 1, and may indicate that the TRS is not triggered (or no TRS trigger, or null state) if the value is 0.

The sum of X, Y and Z bits may be configured to 8 bits or less. One octet including X-bit information, Y-bit information, and/or Z-bit information may be allocated/mapped for each SCell.

Information about different scells may be individually allocated/mapped to different octets.

For such MAC CEs, a new MAC LCID field value different from the existing MAC CE may be applied.

In the example of fig. 10 (b), one octet may be configured to include 1 bit (e.g., a field named T) indicating whether the TRS is triggered, 4 bits of activation information for one SCell, and 2 bits of TRS information. In the example of fig. 10 (b), bits corresponding to C ₀ may be reserved.

In case of multiple SCell activation, multiple octets may be included in the MAC CE. One octet may include information regarding whether a TRS is triggered, one SCell ID, and a TRS ID triggered for the corresponding SCell. The number of octets included in one MAC CE may be variable simultaneously according to the number of scells for which activation is indicated.

Examples 1 to 2

The present embodiment relates to a method of indicating a TRS ID of an additional octet only for an SCell for which SCell activation is indicated.

The example of fig. 10 (c) corresponds to an example of the MAC CE configuration according to the present embodiment.

For example, SCell activation/deactivation may be indicated by a value of a bit position in a bitmap of cell indexes (C ₁ to C ₇ or C ₁ to C ₃₁), similar to existing SCell activation/deactivation MAC CEs.

An additional octet for the corresponding MAC CE may be defined and may include TRS ID information. The added TRS ID information may be included only for each activated SCell, and may not be included for scells for which activation is not indicated. Alternatively, the TRS information for the SCell for which activation is indicated may be indicated by a MAC CE separate from the corresponding MAC CE.

When the SCell activation indication and the TRS ID are included in one MAC CE, a bit (e.g., a field named P) indicating whether the TRS ID indication field is added (or exists) may be defined.

The TRS ID information may be included continuously or sequentially only for the activated SCell. As in the example of fig. 10 (C), the activation for C ₁、C₄ and C ₇ may be indicated among the SCell indices of C ₁-C₇. The first TRS ID field may indicate a TRS ID triggered for SCell index 1 (i.e., C ₁), the second TRS ID field may indicate a TRS ID triggered for SCell index 4 (i.e., C ₄), and the third TRS ID field may indicate a TRS ID triggered for SCell index 7 (i.e., C ₇).

The TRS ID field is illustrated as 3 bits in size, but may be smaller or larger than it. One TRS ID field (e.g., RS ID field for SCell 7) may be defined across two octets. When multiple TRS ID fields do not form one octet, one or more additional R bits may be applied to match the octet unit.

For such MAC CEs, a new MAC LCID field value different from the existing MAC CE may be applied. Alternatively, the same LCID value as the existing SCell activation/deactivation MAC CE may be applied.

Unlike the SCell index corresponding to the state value of the SCell index field in embodiments 1-1, 1-2, each bit position may correspond to a different SCell index according to the SCell index bitmap. That is, embodiments 1-2 can be defined in such a manner that a field for TRS ID is added in an existing SCell activation/deactivation MAC CE.

The addition/presence of the TRS ID may be indicated by the value of the P field. For example, if the value of the P field is 1, it may indicate that one or more TRS ID fields are present, and if the value is 0, it may indicate that no TRS ID field is present. The bit position of the P field is exemplary, and the P field may be located on the highest SCell index (e.g., C ₇) side.

Alternatively, even when the P field is not defined (e.g., when the P field position is defined as R bits), it may be defined that the TRS ID field does not exist when the activated SCell index is not indicated (e.g., when all cs ₁-C₇ are 0 values), and the TRS ID field exists when at least one SCell index is indicated as activated.

Examples 1 to 3

The present embodiment relates to a method of indicating a TRS ID in an additional octet for all scells, whether activated or not.

The example of fig. 10 (d) corresponds to an example of the MAC CE configuration according to the present embodiment.

For example, SCell activation/deactivation may be indicated by a value of a bit position in a bitmap of cell indexes (C ₁ to C ₇ or C ₁ to C ₃₁₀), similar to existing SCell activation/deactivation MAC CEs.

Additional octets are defined for the corresponding MAC CEs, and may include TRS ID information. The TRS ID information added is included for each of all configured scells, and may be added regardless of whether the corresponding SCell is activated. Alternatively, the TRS information for the configured SCell may be indicated by a MAC CE separate from the corresponding MAC CE.

When the SCell activation indication and the TRS ID are included in one MAC CE, a bit (e.g., a field named P) indicating whether the TRS ID indication field is added (or exists) may be defined. In this case, the same LCID value as the existing SCell activation/deactivation MAC CE may be applied.

The TRS ID information may be included continuously or sequentially only for configured scells. The TRS ID information for an unconfigured (or non-added) SCell index or an inactive SCell may be indicated as no TRS trigger, null value or zero value.

In the example of fig. 10 (d), one TRS ID field is defined as a 4-bit size, and when 7 TRS ID fields for 7 scells are included, the last 4 bits may be configured as R bits.

In the above example, the TRS ID field may indicate an ID of TRS related information (e.g., a TRS parameter set) preconfigured by the RRC, and may include the TRS related information indicated by the MAC CE. For example, the TRS related information may be indicated to the terminal explicitly or implicitly. More specifically, the TRS related information may include time/frequency resource location, TCI status, SSB in QCL relation, the number of bursts, time offset (or transmission time point related information), and the like. Some or all of such TRS related information may be configured in advance through RRC signaling, and other or all information may be indicated to the terminal through the MAC CE. When some or all of the TRS related information is transmitted through the MAC CE, the bit length of the TRS ID field (or SCELL RS ID field) may be increased in examples of the present disclosure.

Example 2

The present embodiment relates to a method in which a terminal rapidly reports feedback on a downlink channel state or a base station supports the method.

For example, by quickly performing CSI reporting related information and triggering, the length of the T _{activation_time}+T_{CSI_Reporting} portion in the example of fig. 7 may be reduced. To quickly perform CSI reporting, a combination of one or more of the following examples a-H may be applied.

Basically, information on a TRS trigger and/or information on a CSI-RS trigger attached to a TRS is provided/indicated by a MAC CE for each of scells for which activation is indicated. In addition, information related to CSI reporting based on the triggered TRS and/or CSI-RS (or based on measurements for the TRS and/or CSI-RS) may be indicated by the MAC CE.

Example a. A set of parameters (e.g., RS transmission resources, QCL related information, etc.) for multiple (candidate) TRSs and/or multiple (candidate) CSI-RSs is configured for each SCell in advance through RRC signaling.

Example b. for activated scells, the following information may be indicated, in addition to whether to be transmitted, RS parameter information, and trigger offset information for TRS and/or CSI-RS for each SCell. Based on measurements for RSs (e.g., TRSs and/or CSI-RSs), UL (e.g., PUCCH or PUSCH) resources for CSI report transmission (e.g., CSI UL resource information), CSI report transmission timing (e.g., CSI report timing information), etc., information that may additionally be indicated may include whether a CSI report is sent (e.g., CSI request information).

Example c. information on whether CSI reports are transmitted may be indicated together for all scells for which RSs (e.g., TRSs and/or CSI-RSs) are triggered, or separately for each SCell (or RS).

Example d. Information about UL resources for CSI report transmission may be indicated together for all scells for which CSI reports are indicated, or indicated/configured separately for each SCell (or RS).

Example e. information about CSI reporting timing may be indicated together for all scells for which CSI reporting is indicated, or indicated/configured separately for each SCell (or RS). For example, the information about CSI reporting timing may be indicated/configured as a relative offset (or slot offset) from RS (e.g., TRS and/or CSI-RS) transmission timing, or as a relative offset (or slot offset) from a point in time when the trigger offset=0.

The example f.trs and/or CSI-RS trigger information and corresponding CSI report information may be included in the same single MAC CE or in separate MAC CEs, but may be transmitted through the same PDSCH.

Example g. RRC configuration for TRS may include information related to CSI reporting configuration. When CSI report configuration related information is not provided to the terminal, CSI reporting may not be performed.

Example h. semi-persistent triggers or aperiodic triggers may be applied to CSI reporting. Semi-persistent CSI reporting triggers may be limited to performing CSI reporting only once.

Example 2-1

The present embodiment relates to a method of indicating a CSI-RS transmission trigger and a CSI measurement/reporting operation based thereon by applying a TRS as a reference RS for CSI measurement or by a MAC CE associated with the TRS trigger.

When a TRS-related trigger is indicated by the MAC CE, the TRS may be transmitted aperiodically or in bursts for a specific duration corresponding to T _{activation_time} after a predetermined time offset. Here, the TRS may be used as a reference RS for CSI measurement, and a reference RS of CSI-RS preconfigured through RRC may be used for CSI measurement. To perform tracking (e.g., time tracking) by the general TRS or the aperiodic TRS, a modified form of CSI-RS may be used. For example, tracking and CSI measurement/reporting may be performed based on the TRS. Alternatively, tracking may be performed based on the TRS, and CSI measurement/reporting may be performed by triggering CSI-RS other than the TRS.

Example 2-2

This embodiment relates to a method of triggering CSI reports by a TRS-trigger-related MAC CE.

In the example of fig. 10 (a), a MAC CE including Y-bit information indicating an SCell index for each SCell, Z-bit information indicating a TRS ID, and W-bit information indicating triggering CSI reporting may be defined. In the example of fig. 10 (b), a MAC CE including X-bit information indicating whether a TRS is triggered (or on-off), Y-bit information indicating an SCell index (or ID), Z-bit information indicating a TRS ID (or index), and W-bit information indicating CSI report triggering may be defined. Here, W bit information may be defined by using reserved bits (e.g., C ₀ bits) in fig. 10 (a) and 10 (b).

The CSI report may also not be triggered when the Z-bit TRS ID field in the example of fig. 10 (a) or the X-bit T field in the example of fig. 10 (b) indicates "no TRS trigger" or a null state. Alternatively, CSI measurement/reporting may be triggered based on additional CSI-RS triggers even when the TRS is not triggered.

In the examples of fig. 10 (a) and 10 (b), w+x+y bits or w+x+y+z bits may be configured with 8 bits or less. One octet configured as W bit information, X bit information, Y bit information, and/or Z bit information may be allocated/mapped for each SCell.

In the above example, when the value of W-bit information related to CSI report triggering is 1, a TRS (or aperiodic TRS) -based CSI report is triggered, and when the value is 0, the CSI report may not be triggered. Alternatively, when the value of the W-bit information is 1, CSI reporting based on CSI-RS triggered by the MAC CE triggering TRS is triggered, and when the value is 0, CSI reporting may not be triggered.

Additionally or alternatively, a method in which CSI reporting is triggered when a TRS is triggered in Z-bit information indicating a TRS ID (or index), or a method in which CSI-RS for CSI reporting is triggered when a TRS is triggered in Z-bit information may be applied instead of defining W-bit information related to CSI reporting triggering.

In the examples of fig. 10 (a) and 10 (b), the SCell index, TRS ID, and whether CSI is reported for SCell activation may be indicated by each octet simultaneously.

In addition, when the TRS ID field instead of the CSI report trigger bit (e.g., the W-bit information described above) has a value of "no TRS trigger" or a null state (or corresponding RS ID value), it may be defined that TRS and/or CSI-RS transmission is not triggered and that TRS and/or CSI-RS based CSI reporting is also not triggered.

When the CSI report is triggered, the number of TRS transmissions (e.g., TRS transmissions in a burst manner) and/or information related to the corresponding CSI-RS resources, uplink resources related to the CSI report, information about transmission timing, etc. may be configured in advance between the base station and the terminal through RRC signaling, and, for example, when the SCell is added/changed, the corresponding information may be provided to the terminal.

Even in case of aperiodic RS (e.g., TRS and/or CSI-RS) triggers and CSI reporting triggers, CSI reporting may be performed through PUCCH for one-time transmission or for limited number of repeated transmissions for the purpose of enhancing reliability such as URLLC, not for periodic repeated transmission. The correlation parameters for CSI reporting through the PUCCH in this way may be provided through RRC signaling (e.g., CSI reporting correlation configuration) or may be provided through the MAC CE (e.g., including additional information in the example of fig. 10 (c) or 10 (d)).

The CSI reports may be configured aperiodically or may be configured to be semi-persistent.

In case of CSI reporting through PUSCH, information on transmission-related resource allocation and transmission time of the corresponding PUSCH may be provided to the terminal in advance through configuration/reconfiguration information in RRC procedure for SCell-related addition/change.

Examples 2 to 3

The present embodiment relates to an additional method of triggering CSI reporting through a MAC CE associated with TRS triggering.

For example, CSI reporting may be triggered by a MAC CE such as the example of fig. 10 (c). For example, as shown in fig. 10 (c), one MAC CE including information on CSI reporting may be defined in addition to a bitmap indicating SCell activation and SCell RS (i.e., TRS) ID information. Alternatively, the MAC CE including the TRS ID information and the CSI report information may be defined separately from the MAC CE indicating the bitmap of SCell activation.

In the bitmap indicating SCell activation, a bit indicating whether additional information (e.g., TRS ID information and/or CSI report information) exists/is added may be defined. For example, C ₀ bits previously defined as R bits may be defined as a P field indicating whether additional information exists. In this case, existing LCIDs may be identically reused or new LCIDs may be allocated.

The CSI report information may indicate that CSI reporting is not performed, or may indicate a specific index value related to CSI reporting. For example, by reusing higher layer configured information (e.g., RRC configured CSI-AssociatedReportConfigInfo, SP CSI-RS resource set ID, maxNrOfSemiPersistentPUSCH-Trigger related information, etc.) related to a CSI request field included in DCI, contents indicated by CSI report information through a MAC CE may be defined.

The size of the CSI report information may be 1 bit or more.

Based on the example of fig. 11 (c), the example of fig. 11 (a) may correspond to a MAC CE in which the above-described CSI report information is additionally reflected.

For example, TRS information for SCell activation/deactivation can be added in the form of a bitmap, and trigger information related to CSI report transmission related to the corresponding CSI-RS can be added. The size of SCELL RS ID field corresponding to the TRS ID may be reduced to 2 bits compared to 3 bits in the example of fig. 10 (c), but the scope of the present disclosure is not limited thereto and may be defined as a value of 3 bits or more. When the TRS ID field indicates no TRS trigger or null state and is mapped to indicate that CSI reporting is also not triggered, the CSI report field is not separately defined or may be included in the TRS ID field.

In addition, information on resource allocation related to PUCCH and/or PUSCH transmission and transmission timing for CSI reporting may be provided to the terminal through the MAC CE. In this case, the information bits may be continuously concatenated with a TRS ID and/or CSI-RS (i.e., CSI-RS transmission trigger control for CSI reporting) associated with one SCell. For example, in the example of fig. 11 (a), indication information about resources/time points, etc. may be added after CSI report bits.

The information related to CSI reporting through PUCCH/PUSCH configured/indicated through RRC and/or MAC CE may include PUCCH/PUSCH related resource (e.g., time/frequency resource) information, transmission time (e.g., time offset, number of slots, slot number, etc.) related information, repeated transmission related information (e.g., number of times, period, etc.), and the like.

In embodiments 2-2 and 2-3, when CSI reports are received from a base station a plurality of times, information for enabling/disabling (or activating/deactivating) CSI reports by the base station can be defined in the form of MAC CEs. Such CSI report disabling related MAC CEs may be sent to the terminal on the SCell. For example, at a point in time t ₀ of fig. 7, the terminal may receive a MAC CE on the PCell for activating/triggering a semi-persistent (SP) CSI report on the SCell. In addition, AGC, reception-related preparation, SSB-based synchronization, and the like may be performed in a duration between t ₁ and t ₂, and CSI reporting may be performed at a point in time (e.g., point in time t ₃) after t ₂. Upon receiving one or more CSI reports from the terminal, the base station may send a MAC CE on the SCell, deactivating the SP CSI report on the SCell. In this case, it may be assumed that the TRS can be transmitted in an aperiodic or semi-persistent manner.

When compared to the example of fig. 7, the various examples described in this disclosure are applied, the length of each duration may be shortened or some operations may be overlapped or omitted (e.g., TRS/CSI-RS triggered with SCell activation indication, instead of performing TRS/CSI-RS triggering and receiving after SCell activation).

Considering the case where a particular cell is a known cell for a terminal (e.g., millimeter wave, intra-continuous CA, terminal with information about the cell, such as a previously connected cell), the trigger for CSI reporting and TRS/CSI-RS transmission may not be provided. For example, in the case of millimeter waves, since L1-RSRP for SSB or the like is used by beam management, CSI reporting may not be required.

In the example of fig. 11 (a), as in the example of fig. 11 (c), TRS ID information may be indicated only for an activated SCell, and since the number of octets included in a MAC CE is variable, transmission overhead may be reduced.

The examples of fig. 11 (b) to 12 (b) correspond to modified examples of MAC CEs indicating TRS ID information and CSI reports for all scells (i.e., not limited to activated scells). Unlike the examples of fig. 11 (b) to 12 (b), a MAC CE including TRS information and CSI report information for an SCell may be defined separately from a MAC CE indicating whether the SCell is activated.

In the examples of fig. 11 (b) and 11 (c), 1-bit information indicating whether an octet exists/is added to the SCell activation MAC CE may be included. In addition, 1-bit information indicating whether the TRS is triggered or not and 1-bit information indicating whether the CSI report is triggered or not may be included. Whether CSI reporting is triggered may be mapped to whether TRS is triggered (e.g., when no TRS trigger is indicated), and thus a separate field for whether CSI reporting is triggered may not be defined. For such MAC CEs, different LCID values may be defined or the same LCID value may be applied.

In the example of fig. 11 (b), the AC field may indicate whether the RS ID field exists in an octet corresponding to Ci (cell index) corresponding to the activated cell. It may be indicated that when the value of the AC field is 1, the candidate RS ID field exists, and when the value is 0, the R field exists instead of the RS ID field. In addition, when the AC field is 0, it may indicate that there is no octet added thereafter. In the example of fig. 11 (b), the R field may be replaced with a field indicating whether CSI reporting is triggered. It may indicate that CSI reporting is triggered for SCell corresponding to Ci when the value of CSI reporting field is 1, and that CSI reporting is not triggered for SCell corresponding to Ci when the value is 0.

In the example of fig. 11 (c), the R field may be replaced with a field indicating whether CSI reporting is triggered. It may indicate that CSI reporting is triggered for SCell corresponding to Ci when the value of CSI reporting field is 1, and is not triggered for SCell corresponding to Ci when the value is 0. Alternatively, the R/CSI report field may be replaced with an AC field (refer to the description of fig. 11 (b)).

In the example of fig. 12 (a), one of two R fields of one octet may be replaced with a field indicating CSI report. The remaining one R field may be replaced with an AC field. The descriptions of the AC field and the CSI report field are the same as those in the examples of fig. 11 (b) and 11 (c).

In the example of fig. 12 (b), an RS ID field may exist for Ci corresponding to the activated cell. When the activation/deactivation of scells and the RS ID are configured as separate octets, the Ci field may be replaced with information indicating for which SCell the CSI report is triggered, or may be mapped to corresponding information.

In addition, although there is no trigger for the TRS of the SCell, CSI reporting may be triggered, and in this case, the TRS ID bit may indicate 0 or no TRS trigger or null state.

Example 3

The present embodiment relates to a method for reducing time from SCell activation of a terminal to an overall procedure of CSI feedback, and is supported by a base station.

For example, a method of reducing the overall time of T _HARQ+T_{activate_time}+T_{CSI_Reporting} in the example of fig. 7 will be described.

In the above-described embodiments, it is assumed that the base station receives HARQ-ACK information for MAC CEs including an SCell activation command, and then the terminal prepares and receives TRSs and/or CSI-RSs in the corresponding SCell and reports CSI. The present embodiment relates to a method of simply and quickly performing the start-up of all triggers. For example, it may be reported to the base station through CSI reporting, rather than reporting to the base station through HARQ-ACK feedback, whether the terminal has successfully decoded the MAC CE (or PDSCH carrying it) including the SCell activation command. That is, based on whether the CSI report is received from the terminal, the base station may determine whether the terminal has successfully decoded the MAC CE/PDSCH including the SCell activation command.

In other words, when the SCell activation command, the TRS trigger, the CSI-RS trigger, and/or the CSI report (based on the TRS and/or the CSI-RS) are indicated through a specific MAC CE/PDSCH, the terminal may omit transmission of separate HARQ-ACK feedback for the corresponding MAC CE/PDSCH. Based on the information indicated by the corresponding MAC CE/PDSCH, the terminal may perform CSI reporting.

Alternatively, when only an SCell activation command, a TRS trigger, and/or a CSI-RS trigger is indicated by a specific MAC CE/PDSCH, and a CSI report (based on TRS and/or CSI-RS) is not indicated, the terminal may perform HARQ-ACK feedback transmission for the corresponding MAC CE/PDSCH.

Hereinafter, a method of triggering SCell activation through DCI will be described. That is, unlike the method of indicating SCell activation through MAC CE in the example described above, TRSs for scells may be triggered in advance by PDCCH carrying DCI including CSI request-related information on PCell (or any already activated SCell).

The activated SCell may be indicated by CIF (carrier indicator field) without an SCell activation command by MAC CE and may be activated in a cross-carrier scheduling scheme.

The TRS trigger and the CSI report trigger may be indicated simultaneously by triggering through a CSI request field included in the UL scheduling related DCI (e.g., DCI format 0 series).

The TRS trigger may be performed through information included in the DL scheduling related DCI (e.g., DCI format 1 series), and thus the CSI-RS trigger and CSI report based thereon may be derived.

The base station may determine that the corresponding SCell is activated through CSI reporting of the terminal.

For example, an SCell to be activated may be indicated by a CIF field in the PCell (or SCell capable of cross-carrier scheduling with another SCell). The terminal knows which SCell is indicated for activation through the CIF field in the DCI. When there is no HARQ feedback for the MAC CE command, the base station can know whether the SCell of the terminal is activated only when the CSI report is properly performed. Some information related to CSI reporting may be dynamically indicated through DCI rather than configuring/indicating the same information to a terminal through RRC/MAC CE, thereby reducing RRC/MAC CE transmission overhead. That is, by using CIF fields included in the UL scheduling related DCI format 0 series or the DL scheduling related DCI format 1 series, some or all of SCell activation, PUSCH/PDSCH scheduling, TRS trigger, CSI-RS trigger, CSI reporting trigger (based on TRS/CSI-RS) may be indicated simultaneously through DCI.

Example 4

The present embodiment relates to a method in which a terminal effectively applies QCL information of a TRS, or a base station supports the same method. For example, QCL related information of the TRS/CSI-RS may be utilized in the SCell activation procedure.

The QCL source for the TRS may be SSB. In addition, during SCell activation, the TRS may become a QCL source for another RS. For example, the other RS may be DMRS, CSI-RS, periodic TRS (P-TRS), SSB, or the like.

QCL assumptions related to CSI-RS in fast SCell activation can be summarized as follows.

As in QCL hypothesis example 1, it may be assumed that the QCL source of another RS (DMRS, CSI-RS) is a P-TRS, the QCL source of the P-TRS is a TRS (or AP-TRS), and the QCL source of the TRS (or AP-TRS) is an SSB.

As in QCL hypothesis example 2, SSB may be omitted in the QCL source. For example, it may be assumed that the QCL source of another RS (DMRS, CSI-RS) is a P-TRS and the QCL source of the P-TRS is a TRS (or AP-TRS).

As in QCL hypothesis example 3, it may be assumed that the QCL source of the CSI-RS for initial CSI reporting for completing SCell activation is a TRS (or AP-TRS), and the QCL source of the TRS (or AP-TRS) is an SSB. Alternatively, the SSB may be omitted from the QCL source.

As in QCL hypothesis example 4, it may be assumed that the QCL source of another RS (DMRS, CSI-RS) is P-TRS and the QCL source of P-TRS is SSB. This may correspond to a case where the TRS (or AP-TRS) is not triggered.

In the example of fig. 14, CSI-RS related to the initial CSI report may not be indicated in the MAC CE or DCI. In addition, the indication of the TRS for the AP-TRS based can also be omitted from the MAC CE.

In various examples of the present disclosure described above, provision of SCell configuration (e.g., addition/change) for a terminal in the CA/DC case corresponds to a state in which the terminal stores only information about the SCell in advance, and corresponds to a state in which an actual transmission/reception operation on the SCell is not performed. The actual transmission/reception operation may be performed after receiving an activation command (e.g., MAC CE) for the SCell. With the development of wireless communication systems, a case in which a large amount of data needs to be suddenly transmitted/received in response to a request such as URLLC is considered, and a rapid completion of SCell activation is required for efficient data transmission/reception. Therefore, when a command for activating the SCell is provided from a higher layer as necessary, it is important to quickly perform an operation for transmitting and receiving data through radio resources. According to various examples of the present disclosure described above, since the TRS for the SCell is provided together with the SCell activation command, time tracking for the SCell may be quickly completed and CSI reporting may also be performed if necessary. Therefore, the SCell can be efficiently and quickly used, compared to the conventional method of triggering the RS after SCell activation is completed. Therefore, even when transmission/reception of a large amount of data is suddenly required, a service for rapidly transmitting/receiving a large amount of data while minimizing delay can be realized.

General purpose device to which the present disclosure may be applied

Referring to fig. 15, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through a plurality of radio access technologies (e.g., LTE, NR).

The first wireless device 100 may include one or more processors 102 and one or more memories 104, and may 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 descriptions, functions, processes, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor 102 may transmit a wireless signal including the first information/signal through the transceiver 106 after generating the first information/signal by processing the information in the memory 104. Further, the processor 102 may receive a wireless signal including the second information/signal through the transceiver 106, and then store information obtained through signal processing of 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 store software code including commands for executing all or part of the processes controlled by the processor 102 or for executing descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem/circuit/chip designed to implement wireless communication technologies (e.g., LTE, NR). The transceiver 106 may be coupled to the processor 102 and may transmit and/or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be used with an RF (radio frequency) unit. In this disclosure, a wireless device may mean a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may 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 descriptions, functions, processes, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor 202 may generate the third information/signal by processing the information in the memory 204 and then transmit a wireless signal including the third information/signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information/signals through the transceiver 206, and then store information obtained through signal processing of the fourth information/signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, memory 204 may store software code including commands for executing all or part of the processes controlled by processor 202 or for executing descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 206 may be coupled to the processor 202 and may transmit and/or receive wireless signals via one or more antennas 208. The transceiver 206 may include a transmitter and/or a receiver. The transceiver 206 may be used with an RF unit. In this disclosure, a wireless device may mean a communication modem/circuit/chip.

Hereinafter, the hardware elements of the wireless device 100, 200 will be described in more detail. It is not limited thereto and one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). The one or more processors 102, 202 may generate one or more PDUs (protocol data units) and/or one or more SDUs (service data units) according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts included in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information in accordance with the descriptions, functions, procedures, proposals, methods, and/or operational flow diagrams disclosed in this disclosure. The one or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information to provide to the one or more transceivers 106, 206 according to the functions, procedures, proposals, and/or methods disclosed in the present disclosure. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure.

One or more of the processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more of the processors 102, 202 may be implemented in hardware, firmware, software, or a combination thereof. In an example, one or more ASICs (application specific integrated circuits), one or more DSPs (digital signal processors), one or more DSPDs (digital signal processing devices), one or more PLDs (programmable logic devices), or one or more FPGAs (field programmable gate arrays) may be included in the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure may be implemented by using firmware or software and the firmware or software may be implemented to include modules, procedures, functions, and the like. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present invention may be implemented in firmware or software in the form of codes, commands and/or command sets.

The one or more memories 104, 204 may be coupled to the one or more processors 102, 202 and may be capable of storing data, signals, messages, information, programs, code, instructions, and/or commands in a variety of forms. One or more of the memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drives, registers, cash memory, computer-readable storage medium, and/or combinations thereof. The one or more memories 104, 204 may be located internal and/or external to the one or more processors 102, 202. Further, the one or more memories 104, 204 may be connected to the one or more processors 102, 202 by a variety of techniques, such as a wired or wireless connection.

One or more transceivers 106, 206 may transmit user data, control information, wireless signals/channels, etc. referred to in the methods and/or operational flowcharts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals/channels, etc. referred to in the description, functions, procedures, proposals, methods, and/or operational flowcharts, etc. disclosed in this disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may transmit and receive wireless signals. For example, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Further, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Further, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, wireless signals/channels, etc. mentioned in the description, functions, procedures, proposals, methods, and/or operational flowcharts, etc. of the present disclosure through one or more antennas 108, 208. In the present invention, 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, 206 may process the received user data, control information, wireless signals/channels, etc. by converting the received wireless signals/channels, etc. from RF band signals to baseband signals using the one or more processors 102, 202. The one or more transceivers 106, 206 may convert user data, control information, wireless signals/channels, etc., processed by using the one or more processors 102, 202 from baseband signals to RF band signals. Thus, one or more transceivers 106, 206 may include (analog) oscillators and/or filters.

The above-described embodiments are intended to combine elements and features of the present disclosure in a predetermined form. Each element or feature should be considered optional unless explicitly mentioned otherwise. Each element or feature can be implemented without being combined with other elements or features. Furthermore, embodiments of the present disclosure may include combining some elements and/or features. The order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in or substituted for corresponding elements or features of other embodiments. It is clear that embodiments may include combining claims without explicit dependencies in the claims or may be included as new claims by modification after application.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. The foregoing detailed description is, therefore, not to be taken in a limiting sense, and is intended to be illustrative in every respect. The scope of the invention should be determined by a fair interpretation of the accompanying claims and all changes that come within the meaning and range of equivalency of the disclosure are intended to be embraced therein.

The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in accordance with the methods of the various embodiments in a device or computer, as well as non-transitory computer-readable media that store such software or instructions, etc., and that can be executed in a device or computer. Commands that may be used to program a processing system that performs the features described in this disclosure may be stored in a storage medium or a computer readable storage medium, and the features described in this disclosure may be implemented by using a computer program product that includes such a storage medium. The storage medium may include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state storage devices, and it may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices located remotely from the processor. The memory, or alternatively, the non-volatile memory device in the memory, includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any one of a variety of machine-readable media to control the hardware of the processing system, and may be integrated into software and/or firmware that allows the processing system to interact with other mechanisms using results from embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

Here, the wireless communication technology implemented in the wireless device 100, 200 of the present disclosure may include narrowband internet of things for low power communication and LTE, NR, and 6G. Here, for example, NB-IoT technology may be an example of LPWAN (low power wide area network) technology, may be implemented in standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above names. Additionally or alternatively, wireless communication techniques implemented in the wireless devices 100, 200 of the present disclosure may perform communications based on LTE-M techniques. Here, in an example, the LTE-M technology may be an example of LPWAN technology and may be referred to as various names such as eMTC (enhanced machine type communication) or the like. For example, LTE-M technology may implement 1) LTE CAT 0, 2) LTE CAT M1, 3) LTE CAT M2, 4) LTE non-BL (non-bandwidth limited), 5) LTE-MTC, 6) LTE machine type communication, and/or 7) LTE M, etc., in at least any of various standards including, but not limited to, the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless device 100, 200 of the present disclosure may include at least any one of ZigBee, bluetooth, and Low Power Wide Area Network (LPWAN) that allows for low power communication, and it is not limited to the above names. In an example, the ZigBee technology may generate PANs (personal area networks) 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.

[ Industrial availability ]

The method proposed by the present disclosure is mainly described based on an example applied to the 3GPP LTE/LTE-a, 5G system, but may also be applied to various wireless communication systems other than the 3GPP LTE/LTE-a, 5G system.

Claims

1. A method for receiving a Tracking Reference Signal (TRS) by a terminal in a wireless communication system, the method comprising:

receiving a control element from a network, the control element comprising first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information comprising a field related to a TRS corresponding to each of the N cells; and

At least one TRS for at least one of the N cells is received,

Wherein the size of the control element is based on the value of N.

2. The method according to claim 1, wherein:

The number of fields associated with the TRS is N.

3. The method according to claim 2, wherein:

A field associated with the TRS indicates an identifier of the TRS or includes information indicating a null state or a 0 (zero) value.

4. A method according to claim 3, wherein:

the at least one TRS corresponds to a number of fields of the TRS in which the identifier of the TRS is indicated among the N TRS fields.

5. A method according to claim 3, wherein:

The identifier of the TRS indicates a Channel State Information (CSI) -RS configuration associated with at least one of a resource, periodicity, or offset of the TRS.

6. The method according to claim 1, wherein:

The control element is based on at least one of a configuration for the cell or a configuration for the TRS.

7. The method according to claim 1, wherein:

at least one of the configuration for the cell or the configuration for the TRS is configured by a higher layer.

8. The method according to claim 1, wherein:

The N cells correspond to secondary cells (scells) for which the activation is indicated among cells configured for the terminal.

9. The method according to claim 1, wherein:

The control element is a Medium Access Control (MAC) Control Element (CE).

10. The method according to claim 1, wherein:

the TRS corresponds to an aperiodic CSI-RS used for tracking for an SCell for fast SCell activation.

11. A terminal for receiving a Tracking Reference Signal (TRS) in a wireless communication system, the terminal comprising:

At least one transceiver; and

At least one processor, the at least one processor being connected to the at least one transceiver,

Wherein the at least one processor is configured to:

Receiving, by the at least one transceiver, a control element from the network, the control element including first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information including a field related to a TRS corresponding to each of the N cells; and

At least one TRS for at least one of the N cells is received by the at least one transceiver,

Wherein the size of the control element is based on the value of N.

12. A method for transmitting a Tracking Reference Signal (TRS) by a base station in a wireless communication system, the method comprising:

transmitting a control element to a terminal, the control element including first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information including a field related to a TRS corresponding to each of the N cells; and

At least one TRS for at least one of the N cells is transmitted to the terminal,

Wherein the size of the control element is based on the value of N.

13. A base station for transmitting a Tracking Reference Signal (TRS) in a wireless communication system, the base station comprising:

At least one transceiver; and

Wherein the at least one processor is configured to:

Transmitting, by the at least one transceiver, a control element to a terminal, the control element including first information indicating identifiers for N (N is an integer greater than or equal to 1) cells for which activation is indicated and second information including a field related to a TRS corresponding to each of the N cells; and

At least one TRS for at least one of the N cells is transmitted to the terminal through the at least one transceiver,

Wherein the size of the control element is based on the value of N.

14. A processing apparatus configured to control a terminal in a wireless communication system, the processing apparatus comprising:

At least one processor; and

At least one computer memory operably connected to the at least one processor and storing instructions for performing the method according to any one of claims 1 to 10 based on execution by the at least one processor.

15. At least one non-transitory computer-readable medium storing at least one instruction, wherein:

The at least one instruction, when executed by at least one processor, controls a device in a wireless communication system to perform the method according to any one of claims 1 to 10.