CN113383602B

CN113383602B - Method and apparatus for transmitting and receiving data in wireless communication system

Info

Publication number: CN113383602B
Application number: CN202080012379.1A
Authority: CN
Inventors: 朴珍贤; 卢勳东; 吕贞镐; 杨熙喆; 池衡柱
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-02-15
Filing date: 2020-02-14
Publication date: 2024-04-09
Anticipated expiration: 2040-02-14
Also published as: KR20200099952A; CN113383602A

Abstract

A method performed by a terminal in a wireless communication system is provided. The method comprises the following steps: receiving Downlink Control Information (DCI) from at least one of a plurality of Transmission Reception Points (TRP), the DCI including information for transmitting a configuration indication (TCI) state; identifying whether each of the plurality of TRPs repeatedly transmits the same data via a Physical Downlink Shared Channel (PDSCH) based on a number of Code Division Multiplexing (CDM) groups indicated by the information about the antenna ports, the information about the antenna ports being included in the DCI; and receiving data from the plurality of TRPs based on the recognition result.

Description

Method and apparatus for transmitting and receiving data in wireless communication system

Technical Field

The present disclosure relates to wireless communication systems. More particularly, the present disclosure relates to methods and apparatus for transmitting and receiving data in a wireless communication system.

Background

In order to meet the increasing demand for wireless data services since the commercialization of the 4 th generation (4G) communication system, efforts have been made to develop advanced 5 th generation (5G) or quasi 5G communication systems. For this reason, 5G or quasi 5G communication systems are also referred to as super 4 th generation (4G) network communication systems or Long Term Evolution (LTE) after systems. Implementing a 5G communication system using an over-frequency (mmWave) band (e.g., 60GHz band) has been considered to achieve higher data rates. In order to reduce propagation loss of radio waves in the super-frequency band and increase transmission range, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antenna techniques are discussed. In addition, in order to improve system networks, technologies based on advanced small cells, cloud Radio Access Networks (RANs), ultra dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, coordinated communications, coordinated multipoint (CoMP), receiving end interference cancellation, etc. have been developed for 5G communication systems. In addition, hybrid frequency shift control keys (FSK) and Quadrature Amplitude Modulation (QAM) (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed for 5G communication systems, as well as advanced access techniques such as Filter Bank Multicarrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA).

In addition, the internet is a human-centric connectivity network that human generates and consumes information has evolved to an internet of things (IoT) network in which distributed entities such as things send, receive, and process information without human intervention. Internet of everything (IoT) technology has emerged in combination with the internet of everything, such as big data processing technology operating by connecting to cloud servers. In order to implement IoT, various technologies such as sensing technology, wired/wireless communication and network-based facilities, service interface technology, and security technology are required, and sensor networks for inter-thing communication, machine-to-machine (M2M), machine-type communication (MTC), etc. have been recently studied. Such IoT environments may provide intelligent Internet Technology (IT) services that can create new value related to human life by collecting and analyzing data generated between connected things. With the convergence and combination between existing Information Technology (IT) and various industrial applications, ioT is applicable in various fields such as smart homes, smart buildings, smart cities, smart cars or networking cars, smart grids, healthcare, smart appliances and advanced medical services.

In this regard, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies related to sensor networks, MTC, and M2M communication, etc. have been implemented via 5G communication technologies such as beamforming, MIMO, and array antennas. Even the application of a cloud RAN as the big data processing technology described above can be considered as an example of the convergence between 5G technology and IoT technology.

As described above, with the development of wireless communication systems, there is a need for a method for transmitting and receiving data for network cooperative communication.

The above information is presented merely as background information to aid in the understanding of the present disclosure. No determination has been made as to whether any of the above are applicable to the prior art of the present disclosure, nor has any assertion made.

Disclosure of Invention

Aspects of the present disclosure address at least the problems and/or disadvantages described above and provide at least the advantages described below. Accordingly, aspects of the present disclosure are directed to providing a method and apparatus for transmitting and receiving data between a transmitting node and a terminal to perform cooperative communication in a wireless communication system.

Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the presented embodiments.

Drawings

The foregoing and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings in which:

fig. 1 illustrates a time-frequency domain transmission structure of a Long Term Evolution (LTE), evolved universal terrestrial radio access (E-UTRA), LTE-a-advanced, new Radio (NR), or similar wireless communication system according to an embodiment of the present disclosure;

Fig. 2 shows a frame, subframe, and slot structure in 5G (5 th generation) according to an embodiment of the present disclosure;

fig. 3 illustrates an example of a bandwidth part (BWP) configuration in a wireless communication system according to an embodiment of the present disclosure;

fig. 4 illustrates BWP indication and change in a wireless communication system according to an embodiment of the present disclosure;

fig. 5 illustrates an example of a control resource set configuration of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure;

fig. 6 illustrates resource allocation in the Physical Downlink Shared Channel (PDSCH) frequency domain in a wireless communication system according to an embodiment of the disclosure;

fig. 7 illustrates resource allocation in the PDSCH time domain in a wireless communication system according to an embodiment of the present disclosure;

fig. 8 illustrates resource allocation in the time domain based on subcarrier spacing on a data channel and a control channel in a wireless communication system in accordance with an embodiment of the present disclosure;

fig. 9 illustrates PDSCH repeated transmission in a wireless communication system according to an embodiment of the disclosure;

fig. 10 illustrates protocol stacks of a Base Station (BS) and a User Equipment (UE) of a single cell 10-00, a Carrier Aggregation (CA) 10-10, and a Dual Connectivity (DC) 10-20 in a wireless communication system according to an embodiment of the present disclosure;

Fig. 11 illustrates an antenna port configuration and resource allocation for cooperative communication in a wireless communication system in accordance with an embodiment of the present disclosure;

fig. 12 illustrates a configuration of Downlink Control Information (DCI) for cooperative communication in a wireless communication system according to an embodiment of the present disclosure;

fig. 13A and 13B illustrate repeated transmission of a plurality of transmission-reception points (TRPs) by applying various resource allocation methods in a wireless communication system according to various embodiments of the present disclosure;

fig. 14 illustrates an application of a Transmission Configuration Indicator (TCI) state in a multiple TRP for repeated transmission of each slot in a wireless communication system according to an embodiment of the present disclosure;

fig. 15 illustrates a Redundancy Version (RV) configuration in a repeated transmission of each slot by a plurality of TRPs in a wireless communication system according to an embodiment of the present disclosure;

fig. 16 is a block diagram of a UE in a wireless communication system in accordance with an embodiment of the present disclosure; and

fig. 17 is a block diagram of a BS in a wireless communication system according to an embodiment of the present disclosure.

Throughout the drawings, identical reference numerals will be understood to refer to identical parts, components and structures.

Detailed Description

According to an aspect of the present disclosure, a method performed by a terminal in a wireless communication system is provided. The method comprises the following steps: receiving Downlink Control Information (DCI) from at least one of Transmission Reception Points (TRP), the DCI including first information about a Transmission Configuration Indication (TCI) state and second information about an antenna port; identifying whether each of the TRPs repeatedly transmits the same data via the physical downlink shared channel PDSCH based on the number of code division multiplexing CDM groups indicated by the second information on the antenna ports; and receiving data from the TRP based on the recognition result.

According to another aspect of the present disclosure, a terminal in a wireless communication system is provided. The terminal includes a transceiver and at least one processor. The at least one processor is configured to: controlling a transceiver to receive Downlink Control Information (DCI) from at least one of Transmission Reception Points (TRP), the DCI including first information about a Transmission Configuration Indication (TCI) state and second information about an antenna port; identifying whether each of the TRPs repeatedly transmits the same data via a Physical Downlink Shared Channel (PDSCH) based on a number of Code Division Multiplexing (CDM) groups indicated by the second information about the antenna ports; and controlling the transceiver to receive data from the TRP based on the identification result.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined in the claims and their equivalents. The following description includes various specific details that facilitate this understanding, but are to be considered exemplary only. Accordingly, one of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and the appended claims are not limited to written meanings, but are used only by the inventors for a clear and consistent understanding of the disclosure. Thus, it should be apparent to those skilled in the art that the following descriptions of the various embodiments of the present disclosure are provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It should be understood that the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more such surfaces.

Technical contents that are well known in the art or are not directly related to the present disclosure are omitted in the following description. The subject matter will be more clearly understood by omitting matters that might obscure the subject matter of the present disclosure.

For the same reason, some components in the drawings are enlarged, omitted, or schematically shown. The dimensions of the corresponding elements may not fully reflect their actual dimensions. Like reference numerals refer to like elements throughout the drawings.

The advantages, features and methods for accomplishing these embodiments will be understood more clearly upon reading the following embodiments with reference to the accompanying drawings. However, embodiments of the present disclosure may be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein; rather, these embodiments of the present disclosure are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the embodiments of the disclosure to those skilled in the art. Like numbers refer to like elements throughout.

Throughout this disclosure, the expression "at least one of a, b, or c" means a only, b only, c only, both a and b, both a and c, both b and c, all or a variant thereof.

A terminal may include a User Equipment (UE), a Mobile Station (MS), a cellular telephone, a smart phone, a computer, or a multimedia system capable of communication.

In this disclosure, the controller may also be referred to as a processor.

In this disclosure, a layer (or layer device) may also be referred to as an entity.

It will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. The computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks. The computer program instructions may also be stored in a computer-usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart block or blocks.

Additionally, each block shown in the flow diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It is noted that in alternative embodiments of the present disclosure, the functions noted in the block may occur out of the order. For example, two blocks shown in succession may be executed substantially concurrently or the blocks may be executed in the reverse order.

The term "module" (or sometimes "unit") as used herein refers to a software or hardware component that performs some function, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC). However, the modules are not limited to software or hardware. The modules may be configured to be stored in an addressable storage medium or configured to execute one or more processors. For example, a module may include components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided for by the components and modules may be combined into a fewer number of components and modules or further divided into a greater number of components and modules. In addition, the components and modules may be implemented as one or more Central Processing Units (CPUs) in an execution device or a secure multimedia card. In some implementations, a module may include one or more processors.

The operation principle of the embodiments of the present disclosure will now be described with reference to the accompanying drawings. Descriptions of some well-known techniques that may obscure the present disclosure will be omitted when necessary. In addition, the terms described below are defined in consideration of functions to be described in the present disclosure, but may be changed according to certain practices or intentions of a user or an operator. Accordingly, the terms should be defined according to the description in the present specification. In the following description, a base station is an entity for performing resource allocation for a terminal, and may be at least one of gNB, eNB, nodeB, a base station, a radio access unit, a base station controller, or a network node. The terminal may comprise a UE, MS, cellular phone, smart phone, computer or a multimedia system capable of communication. However, the present disclosure is not limited thereto. A technique in which a BS receives broadcast information from a UE in a wireless communication system will now be described. The present disclosure relates to a communication scheme integrating internet of things (IoT) technology with fifth generation (5G) communication systems that provide higher data transmission rates than fourth generation (4G) systems, and systems employing the same. The present disclosure is applicable to smart services based on 5G communications and IoT-related technologies, such as smart homes, smart buildings, smart cities, smart cars, networking cars, healthcare, digital education, smart retail, security and security services.

In the following description, for convenience of explanation, terms related to broadcast information, control information, state changes (e.g., events), network entities, components of messages and devices, terms related to communication coverage, and the like are presented. That is, the present disclosure is not limited to the following terms, but may use different terms having the same meaning in technical sense.

For ease of description, some terms and names defined in the third generation partnership project long term evolution (3 GPP LTE) standard will be used below. However, the present disclosure is not limited to these terms and definitions and is equally applicable to communication systems conforming to other standards.

Wireless communication systems are evolving from early systems providing voice-oriented services to broadband wireless communication systems providing high data rates and high quality packet data services, such as 3GPP High Speed Packet Access (HSPA), long Term Evolution (LTE) or evolved universal terrestrial radio access (E-UTRA), LTE-Advanced (LTE-a), LTE-Pro, 3GPP2 high rate packet data, ultra mobile broadband, and IEEE 802.16E communication standards.

As a representative example of such a broadband wireless communication system, the LTE system employs Orthogonal Frequency Division Multiplexing (OFDM) for Downlink (DL) and single carrier frequency division multiple access (SC-FDMA) for Uplink (UL). UL refers to a radio link for a UE or MS to transmit data or control signals to an eNode B or BS, and DL refers to a radio link for a BS to transmit data or control signals to a UE or MS. Such multiple access schemes allocate and operate time-frequency resources for carrying data or control information such that individual users do not overlap, i.e., remain orthogonal, with each other, thereby distinguishing the data or control information of each user.

As a future communication system after LTE, a 5G communication system needs to freely reflect various demands from users and service providers in order to support services satisfying the various demands. Services contemplated for 5G communication systems may include enhanced mobile broadband (eMBB), large-scale machine-type communication (mctc), ultra-reliable low-latency communication (URLL), and so forth.

In embodiments of the present disclosure, an eMBB is intended to provide a data rate that is rate enhanced over that supportable by LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, an eMBB is required to provide a peak data rate of 20Gbps in DL and 10Gbps in UL. In addition, the eMBB needs to provide an increased user perceived data rate while providing a peak data rate. To meet these requirements, more enhanced transmission or reception techniques including multiple-input multiple-output (MIMO) transmission techniques are needed. In addition, a frequency bandwidth wider than 20MHz in a 3GHz to 6GHz band or in a 6GHz or higher band may be used instead of 2GHz currently used by LTE, thereby satisfying a data rate required for a 5G communication system.

Meanwhile, in 5G communication systems, mctc is considered to support application services such as internet of things (IoT) application services. In order for mctc to efficiently provide IoT, it may be desirable to support access from a large number of terminals in a cell, enhance terminal coverage, extend battery time, reduce terminal prices, and so on. As IoT is equipped in various sensors and devices to provide communication functionality, it may be considered to support a large number of terminals in a cell (e.g., 1,000,000 terminals/km ² ). In addition, due to the nature of the service, the mctc-enabled terminals are likely to be located in a shadowed area such as a building that cannot be covered, and thus mctc may require a wider coverage than other services provided by the 5G communication system. Terminals supporting mctc need to be low cost terminals and may require a considerable battery life due to the difficulty in frequent replacement of the battery in the terminal.

Finally, ultra-reliable low latency communications (URLLC) are required to provide ultra-low latency and ultra-reliable communications for special purpose cellular-based wireless communication services, such as remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote healthcare, emergency alerts, and the like. Example(s)For example, the URLLC service needs to meet sub-millisecond (less than 0.5 millisecond) air interface delays and at the same time needs to meet less than 1 packet loss/every 10 th ^-5 Error rate of individual packets. Thus, for the URLLC service, the 5G system needs to provide a smaller Transmission Time Interval (TTI) than other services, and at the same time, needs a design of allocating a wide range of resources in a frequency band. MMTC, URLLC, and eMBB are examples of different types of services, and embodiments of the present disclosure are not limited to these types of services.

The aforementioned services considered in 5G communication systems need to be provided by being integrated together on a frame basis. In other words, for efficient resource management and control, individual services may be controlled and transmitted as a system as a whole without being operated separately.

While the embodiments disclosed below will now focus on, for example, LTE-a, LTE Pro or NR systems, they are equally applicable to other communication systems having similar technical contexts or channel types. In addition, embodiments of the present disclosure will also find application to other communication systems with modifications as determined by one of ordinary skill in the art without departing significantly from the scope of the present disclosure.

The present disclosure relates to a method and apparatus for repeatedly transmitting data and control signals between a plurality of transmitting nodes performing cooperative communication and a terminal to improve communication reliability.

According to the present disclosure, when network cooperative communication is used in a wireless communication system, reliability of receiving data/control signals at a terminal can be improved.

The frame structure in the 5G system will now be described in more detail with reference to the accompanying drawings.

Fig. 1 illustrates a transmission structure in the time-frequency domain of LTE, LTE-A, NR, or similar wireless communication systems, according to an embodiment of the present disclosure.

In other words, fig. 1 shows a basic structure of a time-frequency domain, which is a radio resource domain of a transmission data or control channel in a 5G system.

Referring to fig. 1, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The basic resource units in the time and frequency domains are resource elements(RE) 1-01, which may be defined as one Orthogonal Frequency Division Multiplexing (OFDM) symbol 1-02 of subframe 1-10 in the time domain and one subcarrier 1-03 in the frequency domain. In the frequency domain of the power supply,the (e.g., 12) consecutive REs may constitute a single Resource Block (RB) 1-04.

Fig. 2 shows frame, subframe, and slot structures in 5G according to an embodiment of the present disclosure.

For example, fig. 2 shows a slot structure considered in a 5G system.

Referring to fig. 2, an example of a frame 2-00, subframe 2-01, and slot 2-02 structure is shown. Frame 2-00 may be defined as 10ms. Subframe 2-01 may be defined as 1ms, so a total of 10 subframes 2-01 may constitute one frame 2-00. Slots 2-02 or 2-03 may be defined as having 14 OFDM symbols (i.e., the number of symbols per 1 slotEqual to 14). One subframe 2-01 may include one or more slots 2-02 or 2-03, and the number of slots 2-02 or 2-03 per 1 subframe may vary depending on the subcarrier spacing set value μ (2-04 and 2-05). In the example of fig. 2, the subcarrier spacing settings are 0 and 1, i.e., μ=0 (2-04) and μ=1 (2-05). In case μ=0 (2-04), one subframe 2-01 may include one slot 2-02; and in case of μ=1 (2-05), one subframe 2-01 may include two slots 2-03. That is, the number of slots per subframe +. >Changeable, corresponding to the number of time slots per frame +.>Can vary. Depending on the subcarrier spacing set value mu +.>And->Can be defined as in table 1 below.

TABLE 1

In NR, one component carrier or serving cell may include 250 RBs or more. Thus, the UE may consume excessive power when the UE always receives the entire serving cell bandwidth as in LTE. To solve this problem, the BS may configure one or more bandwidth parts (BWP) for the UE to support that the UE can change a reception area in the cell. In NR, the BS may configure the UE with "initial BWP" which is a bandwidth of a control resource set (CORESET) #0 (or Common Search Space (CSS)) in a Master Information Block (MIB). Subsequently, the BS may configure the first BWP for the UE through Radio Resource Control (RRC) signaling and then inform configuration information of the at least one BWP, which may be indicated later in Downlink Control Information (DCI). Thereafter, the BS may indicate which frequency band the UE may use by informing the BWP ID in the DCI. When the UE fails to receive DCI in the currently allocated BWP within a certain period of time, the UE returns to "default BWP" to attempt to receive the DCI. Fig. 3 illustrates an example of a BWP configuration in a wireless communication system according to an embodiment of the present disclosure.

Fig. 3 illustrates an example of a BWP configuration in a 5G communication system according to an embodiment of the present disclosure.

Referring to fig. 3, two BWP, bwp#1 3-05 and bwp#2 3-10 are configured in the ue bandwidth 3-00. The BS may configure one or more BWP for the UE and configure information as in table 2 for each BWP.

TABLE 2

In addition to the configuration information as described in table 2, various parameters related to BWP may be configured for the UE. The above information may be transmitted to the UE by the BS through upper layer signaling (e.g., RRC signaling). At least one of the configured one or more BWP may be activated. Whether or not to activate the configured BWP may be semi-statically notified from the BS to the UE through RRC signaling, or dynamically notified from the BS to the UE through a Medium Access Control (MAC) Control Element (CE) or DCI.

Such BWP configuration supported by the 5G communication system may be used for various purposes.

For example, when the bandwidth supported by the UE is smaller than the system bandwidth, the bandwidth supported by the UE may be supported through a BWP configuration. For example, in table 2, when a frequency location (configuration information 2) of BWP is configured for the UE, the UE may transmit or receive data at a specific frequency location in a system bandwidth.

In another example, to support different parameter sets, the BS may configure a plurality of BWP for the UE. For example, to support data transmission and reception for a UE using 15KHz subcarrier spacing and 30KHz subcarrier spacing, two BWPs may be configured to use 15KHz and 30KHz subcarrier spacing, respectively. Different BWPs may be frequency division multiplexed, and for data transmission and reception with a specific subcarrier spacing, BWPs configured with the subcarrier spacing may be activated.

In another example, in order to reduce power consumption of the UE, the BS may configure the UE with BWP having different bandwidth sizes. For example, when a user equipment supports a very large bandwidth (e.g., a bandwidth of 100 MHz) and transmits or receives data in the bandwidth, the user equipment consumes a very large power. In particular, the DL control channels of large bandwidth (100 MHz) are unnecessarily monitored in the absence of traffic, which can be very inefficient in terms of power consumption. Accordingly, in order to reduce power consumption of the UE, the BS may configure the UE with BWP (e.g., 20MHz BWP) having a relatively small bandwidth. In the absence of traffic, monitoring may be performed at a BWP of 20 MHz; and when data occurs, the data may be transmitted or received at BWP of 100MHz under the instruction of the base station. Fig. 4 illustrates BWP indication and change in a wireless communication system according to an embodiment of the present disclosure.

Fig. 4 illustrates a method of dynamically changing a BWP configuration according to an embodiment of the present disclosure.

Referring to fig. 4, as described above in connection with table 2, the BS may configure one or more BWP and inform the UE of information about bandwidth of each BWP, frequency location of BWP, parameter set of BWP, etc. in the configuration of BWP. In fig. 4, two BWP are configured for the UE, BWP #1 4-05 and BWP #2 4-10 in the UE bandwidth 4-00. One or more of the configured BWP may be activated, for example, in fig. 4, one BWP is activated. Specifically, in fig. 4, BWP #1 4-05 of BWP configured in slot #0 4-25 is activated, and the UE may monitor a Physical Downlink Control Channel (PDCCH) configured in control resource set #1 4-45 of BWP #1 4-05 and transmit or receive data 4-55 in BWP #1 4-05. The set of control resources for the UE to receive the PDCCH may be different depending on which of the configured BWP is activated, and accordingly, the bandwidth for the UE to monitor the PDCCH may be different. For example, conversely, the UE may monitor the PDCCH in control resource set #2 4-50.

The BS may also transmit an indicator for switching the BWP configuration. The configuration of switching BWP may be equivalently regarded as activating a specific BWP (e.g., switching from BWP a to BWP B). The BS may transmit a configuration switch indicator to the UE, and then the UE may determine BWP to be activated by applying configuration switch based on the configuration switch indicator at a specific point in time after receiving the configuration switch indicator from the BS, and monitor the PDCCH in a control resource set configured for the activated BWP.

In fig. 4, the BS may transmit a configuration switch indicator 4-15 to the UE in slot #1 4-30, the configuration switch indicator 4-15 indicating that BWP activation switches from BWP #1 4-05 to BWP #24-10. Upon receiving the indicator, the UE may activate bwp#24-10 according to the description of the indicator. In this case, a transition time of 4-20 for BWP handover may be required, and thus the time at which the application BWP handover is activated may be determined. For example, in FIG. 4, after receiving the configuration switch indicator 4-15, a transition time of 4-20 of one slot is required. During the transition time 4-20, no data transmission or reception may be performed in 4-60. Accordingly, BWP #24-10 is activated in slot #2 4-35, and an operation of transmitting or receiving a control channel and data can be performed in the activated BWP. Similarly, BWP #24-10 may be activated in slot #3 4-40 and an operation of transmitting or receiving a control channel and data may be performed in the activated BWP.

The BS may pre-configure one or more BWP for the UE via upper layer signaling (e.g., RRC signaling), and configure the handover indicators 4-15 may indicate activation by: the configuration switch indicator 4-15 is mapped to one of the BWP preconfigured by the BS. For example, log ₂ The N-bit indicator may select and indicate one of the preconfigured N BWPs. An example of indicating configuration information about BWP using a 2-bit indicator is shown in table 3.

TABLE 3

Indicator value	BWP configuration
		00	Bandwidth configuration A configured by upper layer signaling
01	Bandwidth configuration B configured by upper layer signaling
		10	Bandwidth configuration C configured by upper layer signaling
11	Bandwidth configuration D configured by upper layer signaling

The configuration switch indicator 4-15 of BWP as described in fig. 4 may be transmitted from the base station to the UE in the type of MAC CE signaling or layer 1 (L1) signaling (e.g., common DCI, group-shared DCI, UE-specific DCI).

Based on the configuration switch indicators 4-15 of BWP as described in fig. 4, when BWP activation is applied may follow the following way: when to apply the configuration switch may be determined according to a predetermined value (e.g., N (1) slots after receiving the configuration switch indicator), set for the UE by the BS through upper layer signaling (e.g., RRC signaling), or partially notified in the configuration switch indicators 4-15. Alternatively, when to apply the configuration switch may be determined by a combination of the above methods. The UE may start applying the changed configuration from the point of time obtained in the above method after receiving the configuration switch indicator 4-15 of BWP.

The DL control channel in the 5G communication system will now be described in detail with reference to the related drawings.

Fig. 5 illustrates an example of configuring a control resource set of a DL control channel in a wireless communication system according to an embodiment of the present disclosure.

In particular, fig. 5 illustrates an example of transmitting a control resource set (or CORESET) of a DL control channel in a 5G wireless communication system.

Referring to fig. 5, two control resource sets, control resource set #1 5-01 and control resource set #2 5-02, are configured in BWP 5-10 in the frequency domain and slot 5-20 in the time domain. In the frequency domain, the control resource sets 5-01 and 5-02 may be configured in a specific frequency resource 5-03 in the entire UE BWP 5-10. In the time domain, control resource sets 5-01 and 5-02 may be configured in one or more OFDM symbols and may be defined by a control resource set duration of 5-04. In the example of fig. 5, control resource set #1 5-01 is configured to have a control resource set duration of two symbols, and control resource set #2 5-02 is configured to have a control resource set duration of one symbol.

As described above, in 5G, a control resource set may be configured for a UE by a BS through upper layer signaling (e.g., system Information (SI), MIB, or RRC signaling). Configuring the control resource set for the UE is to provide the UE with information such as the control resource set ID, the frequency location of the control resource set, the symbol length of the control resource set, etc. For example, the information in table 4 may be included in the above information.

TABLE 4

In table 4, TCI-statepdcch (abbreviated TCI state) configuration information may include information about one or more synchronization signal/physical broadcast channel block indexes having a quasi-co-located (QCL) relationship with demodulation reference signals transmitted in corresponding control resource sets or channel state information reference signal (CSI-RS) indexes.

Hereinafter, a method of allocating time-frequency resources for data transmission in NR will be described.

In NR, in addition to allocation of candidate frequency domain resources by BWP indication, the following specific frequency domain resource allocation (FD-RA) may be provided.

Fig. 6 illustrates resource allocation in the PDSCH frequency domain in a wireless communication system according to an embodiment of the present disclosure.

Specifically, FIG. 6 shows three methods of frequency resource allocation in NR, namely type 06-00, type 1 6-05 and dynamic switching 6-10 configurable by upper layers.

Referring to fig. 6, when a UE is configured by upper layer signaling to use only resource type 0 (6-00), some DCIs for allocating PDSCH to the UE have a structure including N _RBG A bitmap of bits. The conditions thereof will be described later. N (N) _RBG Refers to the number of Resource Block Groups (RBGs) determined according to the Size of BWP allocated by the BWP indicator and the upper layer parameters RBG-Size in table 5 as follows, and data is transmitted in the RBG represented by 1 based on the bitmap.

TABLE 5

Size of bandwidth portion	Configuration 1	Configuration 2
			1-36	2	4
37-72	4	8
			73-144	8	16
145-275	16	16

When the UE is configured by upper layer signaling to use only resource type 1 (6-05), some DCIs for allocating PDSCH to the UE have a structure includingBit frequency domain resource allocation information. The conditions thereof will be described later. This may allow the BS to set the length of the starting VRB 6-20 and the frequency domain resources 6-25 allocated consecutively starting from the starting VRB 6-20.

When the UE is configured to use the resource type 0 and the resource type 1 through upper layer signaling (6-10), some DCIs for allocating PDSCH to the UE have frequency domain resource allocation information in bits 6-35, and bits 6-35 correspond to the larger one of the payload 6-15 for configuring the resource type 0 and the payload 6-20 for configuring the resource type 1. The conditions thereof will be described later. In this case, one bit 6-30 may be added to the Most Significant Bit (MSB) of the frequency domain allocation information in the DCI, and when the bit is "0", it indicates that resource type 0 is used, and when the bit is "1", it indicates that resource type 1 is used.

Fig. 7 illustrates resource allocation in the PDSCH time domain in a wireless communication system according to an embodiment of the present disclosure.

For example, fig. 7 shows an example of time domain resource allocation in NR.

Referring to fig. 7, the bs may be based on a data channel and a control channel (μ) set using an upper layer _PDSCH ，μ _PDCCH ) Subcarrier spacing (SCS) on and scheduling offset K ₀ And a starting position 7-00 and a length 7-05 of an OFDM symbol in a slot dynamically indicated in the DCI to indicate a position of PDSCH resources in the time domain.

Fig. 8 illustrates resource allocation in the time domain based on SCS on a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.

Referring to fig. 8, the data channel and the control channel have the same SCS 8-00 (μ) _PDSCH ＝μ _PDCCH ) In this case, since the data and control slot numbers are the same, the BS and UE would expect to shift K according to the preset slot ₀ A scheduling offset occurs. On the other hand, the data channel and the control channel have different SCS 8-05 (μ) _PDSCH ＝μ _PDCCH ) In this case, since the data and control slot numbers are different, the BS and the UE may expect a slot offset K preset according to the SCS based on the PDCCH ₀ A scheduling offset occurs.

In NR, in order to effectively receive a control channel of a UE, various DCI formats for different purposes are provided as shown in table 6.

TABLE 6

For example, the BS may schedule PDSCH in one cell using DCI format 0_0 or DCI format 0_1.

When DCI format 0_1 is transmitted with a cyclic redundancy check scrambled by a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (CS-RNTI), or a new RNTI, it includes at least the following information:

Identifier of DCI format (1 bit): as DCI format indicator, always set to 1

-frequency domain resource allocation (N _RBG Bits orBit): indicates frequency domain resource allocation and when monitoring DCI format 1_0 in UE-specific search space,/v->Is the size of the active DL BWP; otherwise, go (L)>Is the size of the initial DL BWP. N (N) _RBG Is the number of resource block groups. The method specifically refers to frequency domain resource allocation.

-time domain resource allocation (0-4 bits): time domain resource allocation is indicated according to the above description.

-mapping of VRBs to PRBs (1 bit): for mapping of non-interleaved VRPs to PRBs, the bit is 0; for the interleaved VRP to PRB mapping, the bit is 1.

Modulation and coding scheme (5 bits): indicating the modulation order and coding rate used for PDSCH transmission.

-new data indicator (1 bit): the initial transmission or retransmission is indicated according to whether it is switched.

Redundancy version (2 bits): representing redundancy versions for PDSCH transmissions.

HARQ process number (4 bits): the HARQ process number for PDSCH transmission is indicated.

-downlink allocation index (2 bits): DAI indicator.

TPC commands (2 bits) for scheduled PUCCH: PUCCH power control indicator.

-PUCCH resource indicator (3 bits): a PUCCH resource indicator indicating one of 8 resources configured by an upper layer.

PDSCH to harq_feedback timing indicator (3 bits): a HARQ feedback timing indicator indicating one of eight feedback timing offsets set by an upper layer.

When DCI format 1_1 is transmitted along with a CRC scrambled by a C-RNTI, CS-RNTI, or new RNTI, it includes at least the following information:

identifier of DCI format (1 bit): as the DCI format indicator, 1 is always set.

-carrier indicator (0 or 3 bits): the CC (or cell) that transmitted the PDSCH allocated in the DCI is indicated.

-a bandwidth part indicator (0, 1 or 2 bits) indicating that BWP of PDSCH allocated in DCI is transmitted.

Frequency domain resource allocation (determining payload from the frequency domain resource allocation): indicating the frequency domain resource allocation,is the size of the active DL BWP. The method specifically refers to frequency domain resource allocation.

-mapping of VRBs to PRBs (0 or 1 bit): for mapping of non-interleaved VRPs to PRBs, the bit is 0; for the interleaved VRP to PRB mapping, the bit is 1. When the frequency domain resource allocation is set to resource type 0, it has 0 bits.

Size indicator of PRB combination: bit 0 when the upper layer parameter prb-bundledtype is not set or is set to "static" and bit 1 when prb-1 is set to "dynamic".

-rate matching indicator (0, 1 or 2 bits): indicating a rate matching pattern.

-ZP CSI-RS trigger (0, 1 or 2 bits): an indicator of the aperiodic ZP CSI-RS is triggered.

For transport block 1:

modulation and coding scheme (5 bits): representing the modulation order and coding rate used for PDSCH transmission.

For transport block 2:

-downlink allocation index (0, 2 or 4 bits): DAI indicator

TPC commands (2 bits) for scheduled PUCCH: PUCCH power control indicator.

-antenna port (4, 5 or 6 bits): DMRS ports and CDM groups indicating no data.

-transmitting a configuration indication (0 or 3 bits): TCI indicator.

-SRS request (2 or 3 bits): SRS transmission request indicator

-CBG transfer information (0, 2, 4, 6 or 8 bits): an indicator indicating whether a code block group on the allocated PDSCH is transmitted. "0" indicates a corresponding CBG to be not transmitted, and "1" indicates a CBG to be transmitted.

CBG erasure information (0 or 1 bit): an indicator indicating whether a previous CBG is contaminated, wherein a "0" indicates that the previous CBG may be contaminated and a "1" indicates that the previous CBG may be combined for receiving a retransmission.

DMRS sequence initialization (0 or 1 bit): DMRS indicator of scrambling ID selection.

The number of DCIs of different sizes that the UE can receive in each slot in the respective cells is at most 4. The number of different sized DCIs scrambled by the C-RNTI that the UE can receive in each slot in the respective cell is at most three.

Fig. 9 illustrates PDSCH repeated transmission in a wireless communication system according to an embodiment of the present disclosure.

Referring to fig. 9, in NR, the same PDSCH is repeatedly transmitted in 9-00 to increase the reliability of PDSCH reception by the UE. The BS may set the number of PDSCH transmission repetitions, e.g., PDSCH-aggregation factor in PDSCH-Config, and when the number of transmission repetitions is set, the scheduled PDSCH in the DCI may be repeatedly transmitted in the same number of slots as the number of consecutive transmission repetitions in 9-05. In a slot, all transmission repetitions of the PDSCH may be allocated the same time resource, which may be a starting position 7-00 and a length 7-05 of an OFDM symbol in one slot indicated by DCI, as shown in fig. 7. In addition, the same MCS may be applied to all transmission repetitions of PDSCH. The UE may desire to perform repeated transmission of PDSCH in a single layer. In addition, as shown in table 7, the RV of the repeatedly transmitted PDSCH may be determined according to the RV value indicated in the DCI of the scheduled PDSCH and the index of the repeatedly transmitted PDSCH.

TABLE 7

In table 7, n may indicate an index of each of PDSCH transmission repetition numbers determined by an upper layer in 9-10 and 9-15.

Fig. 10 illustrates protocol stacks of BSs and UEs of a single cell, carrier Aggregation (CA), and Dual Connectivity (DC) in a wireless communication system according to an embodiment of the present disclosure.

Referring to fig. 10, radio protocols of the next generation mobile communication system in each of the UE and the NR BS may include an NR service data adaptation protocol (NR SDAP) 10-25 or 10-70, an NR packet data convergence protocol (NR PDCP) 10-30 or 10-65, an NR radio link control (NR RLC) 10-35 or 10-60, and an NR media access control (NR MAC) 10-40 or 10-55.

The primary functions of NR SDAP 10-25 or 10-70 can include some of the following functions:

-a user plane data transfer function;

-a mapping function between quality of service (QoS) flows and data bearers for both DL and UL;

-a tagging function of QoS flow IDs for both UL and DL; and

-a mapping function of reflected QoS flows of UL SDAP PDUs to DRBs.

For the SDAP layer device, the UE may receive in an RRC message a configuration of whether to use a header of the SDAP layer device or whether to use SDAP layer device functionality, and when the SDAP header is configured, receiving a 1-bit non-access stratum reflective QoS (NAS reflective QoS) indicator and a 1-bit reflective QoS access stratum reflective QoS (AS reflective QoS) indicator may indicate that the UE updates or reconfigures the mapping information between QoS flows and data bearers for the uplink or downlink. The SDAP header may include QoS flow ID information indicating QoS. QoS flow ID information may be used for data processing priority, scheduling, etc. for smoother service.

The primary functions of NR PDCP 10-30 or 10-65 can include some of the following functions:

header compression and decompression functions (e.g., header compression and decompression: ROHC only);

-a user data transfer function;

-a sequential transmission function (e.g. sequential transmission of upper layer PDUs);

-an out-of-order transfer function (e.g. out-of-order transfer of upper layer PDUs);

a reordering function (e.g., reordering of PDCP PDUs for reception);

-a duplicate detection function (e.g. duplicate detection of lower layer SDUs);

-a retransmission function (e.g. retransmission of PDCP SDUs);

-an encryption and decryption function; and

a timer-based SDU discard function (e.g., timer-based SDU discard in the uplink).

The reordering function of the NR PDCP device may refer to a function of reordering PDCP PDUs received from a lower layer based on a PDCP Sequence Number (SN). The reordering function of the NR PDCP device may include a function of transmitting data to an upper layer in a reordered order or directly transmitting data to an upper layer regardless of the order. In addition, the reordering function of the NR PDCP device may include a function of reordering sequences to record lost PDCP PDUs, a function of reporting a status of the lost PDCP PDUs to a transmitting end, or a function of requesting retransmission of the lost PDCP PDUs.

The primary functions of NR RLC 10-35 or 10-60 may include some of the following functions:

-a data transmission function (e.g. transmission of upper layer PDUs);

ARQ functionality (e.g., by ARQ error correction);

concatenation, segmentation and reassembly functions (e.g., concatenation, segmentation and reassembly of RLC SDUs);

-a re-segmentation function (e.g. re-segmentation of RLC data PDUs);

a reordering function (e.g., reordering of RLC data PDUs);

-a repetition detection function;

-an error detection function (e.g. protocol error detection);

-RLC SDU discard function; and

RLC re-establishment function.

The sequence transfer function of the NR RLC device may refer to a function of sequentially transferring RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of receiving, reassembling, and delivering a plurality of RLC SDUs generated by segmentation of an original RLC SDU, and a function of reordering received RLC PDUs based on RLC SN or PDCP SN. In addition, the in-sequence delivery function of the NR RLC device may include a function of reordering sequences to record missing RLC PDUs, a function of reporting a status of the missing RLC PDUs to a transmitting end, or a function of requesting retransmission of the missing PDCP PDUs. In addition, the sequential transfer function of the NR RLC device may include: when there is a missing RLC SUD, transmitting RLC SDUs preceding the missing RLC SDUs to an upper layer in sequence; or when the timer expires due to the missing RLC SDU, sequentially transmitting all RLC SDUs received before the timer is started to an upper layer; or a function of sequentially transmitting all RLC SDUs currently received to an upper layer when a timer expires while there is a missing RLC SDU. In addition, the in-order delivery function of the NR RLC device may process RLC PDUs by processing the RLC PDUs in the order of reception without considering the order (unordered delivery) (or in the order of arrival without considering the order of SNs), or when RLC PDUs are segmented, reconstruct the segments stored in a buffer or received into complete RLC PDUs, process the RLC PDUs, and deliver them to the PDCP device. The NR RLC layer may not include a concatenation function, and the concatenation function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

The out-of-order transfer function of the NR RLC device may refer to a function of directly transferring RLC SDUs received from a lower layer to an upper layer regardless of the order of RLC SDUs. The out-of-order delivery function of the NR RLC device may include a function of receiving, reassembling, and delivering a plurality of RLC SDUs generated by segmentation of an original RLC SDU, and a function of storing RLC SNs or PDCP SNs of the received RLC PDUs and reordering the received RLC PDUs based on the RLC SNs or PDCP SNs to record missing RLC PDUs.

The NR MAC layer 10-40 or 10-55 may be connected to a plurality of NR RLC layer devices configured in the same UE, and the main functions of the NR MAC layer 10-40 or 10-55 may include some of the following functions:

-a mapping function (e.g. mapping between logical channels and transport channels);

multiplexing and demultiplexing functions (e.g., multiplexing/demultiplexing of MAC SDUs);

-a scheduling information reporting function;

HARQ functionality (e.g. by HARQ error correction);

-a logical channel priority control function (e.g. priority handling between logical channels of one UE);

UE priority control functions (e.g., priority handling between UEs by dynamic scheduling);

-an MBMS service identification function;

-a transport format selection function; and

-a filling function.

The NR PHY layer 10-45 or 10-50 may perform channel coding and modulation on upper layers, form data into OFDM symbols and transmit on a radio channel, or may demodulate OFDM symbols received on a radio channel, perform channel decoding on the OFDM symbols and transmit the result to the upper layers.

The details of the radio protocol architecture of fig. 10 may vary differently depending on the carrier (or cell) operating scheme. For example, when the BS transmits data to the UE based on a single carrier (or cell), the BS and the UE use a protocol architecture having a single structure per layer as in 10-00. When the BS transmits data to the UE based on CA in which a single Transmission Reception Point (TRP) uses a plurality of carriers, the BS and the UE use a protocol architecture in which each layer up to the RLC layer has a single structure and has PHY layers multiplexed by the MAC layer as in 10-10. In another example, when the BS transmits data to the UE based on DC in which a plurality of TRPs use a plurality of carriers, each layer of the BS and the UE use the SDAP and the PDCP has a single structure and has a protocol architecture of PHY layers multiplexed by the PDCP.

Referring to the description of the DCI structure, PDSCH time/frequency resource allocation and the repeated PDSCH transmission procedure performed based on the DCI structure and PDSCH time/frequency resource allocation, NR uses a single transmission point/panel/beam in PDSCH repeated transmission in release 15. Applications using cooperative communication of multiple transmission points/panels/beams in PDSCH repeated transmissions may achieve more robust performance (e.g., channel blocking), but they need to support additional standards. In addition, in the NR of the current release 15, a plurality of consecutive slots are used in PDSCH repeated transmission, which means that delay required for reception and decoding of PDSCH is long. Delay may be reduced when PDSCH to be repeatedly transmitted using cooperative communication is transmitted at multiple transmission points/panels/beams, but additional standards need to be supported for this. Accordingly, the present disclosure provides a method of achieving improved reliability and reduced delay in PDSCH repeated transmissions using cooperative communications.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. The description of the related functions or constructions of the present disclosure may be skipped when it is determined that the subject matter of the present disclosure is not clear. In addition, terms described later are defined in consideration of functions to be described in the present disclosure, but may be changed according to certain practices or intentions of a user or an operator. Accordingly, the terms should be defined based on the description in the present specification.

In the following description, a BS is an entity for performing resource allocation for a terminal, and may be at least one of a gNB, an eNB, a node B, a radio access unit, a base station controller, or a network node. The terminal may comprise a UE, MS, cellular phone, smart phone, computer or a multimedia system capable of communication. While the following embodiments of the present disclosure will now focus on, for example, NR, LTE or LTE-a systems, they are equally applicable to other communication systems having similar technical contexts or channel types. In addition, embodiments of the present disclosure will also find application to other communication systems with modifications as determined by one of ordinary skill in the art without departing significantly from the scope of the present disclosure.

The present disclosure is applicable to Frequency Division Duplex (FDD) and Time Division Duplex (TDD) systems.

In the following description, upper layer signaling is a method of transmitting a signal from a BS to a UE on a downlink data channel of a PHY layer or transmitting a signal from a UE to a BS on an uplink data channel of a PHY layer, which may also be referred to as RRC signaling, PDCP signaling, or MAC CE.

The UE may determine whether to apply the cooperative communication in various ways, for example, by having a PDCCH to which a PDSCH of the cooperative communication is applied in a specific format, by having a PDCCH to which a PDSCH of the cooperative communication is applied include a specific indicator indicating whether to apply the cooperative communication, by having a PDCCH to which a PDSCH of the cooperative communication is applied be scrambled by a specific RNTI, or assuming that the cooperative communication is applied in a specific portion indicated by an upper layer. Hereinafter, for convenience of explanation, an example when the UE receives the PDSCH to which cooperative communication is applied based on a condition similar to the aforementioned condition may be referred to as a non-coherent (NC) Joint Transmission (JT) case.

Determining the priority between a and B may mean various examples such as selecting one of a and B having a higher priority according to a preset priority rule and performing a corresponding operation, or omitting or discarding the other of the lower priorities.

The above examples will now be described by way of several embodiments, in which case one or more embodiments may be applied simultaneously or in combination, rather than individually.

First embodiment: DCI reception of NC-JT

Unlike the existing communication system, the 5G wireless communication system can support not only a service requiring a higher transmission speed but also a service with a very short delay and a service requiring a higher connection density. In a wireless communication network including a plurality of cells, TRPs, or beams, cooperative communication between the respective cells, TRPs, and/or beams is one of key technologies that can satisfy various service demands by increasing UE received signal strength or efficiently performing interference control between the respective cells, TRPs, and/or beams. According to embodiments of the present disclosure, collaborative communications may also be referred to as collaborative transmissions.

Joint Transmission (JT) is a representative transmission technique for cooperative communications that may support UEs with different cells, TRPs, and/or beams to increase the signal strength received by the UE. Meanwhile, since channels between respective cells, TRPs, and/or beams and UEs may have significantly different characteristics, each link between each cell, TRP, and/or beam and UE needs to apply different precoding, MCS, resource allocation, and the like. In particular, in the case of NC JTs supporting incoherent precoding between individual cells, TRPs and/or beams, individual DL transmission information configuration of individual cells, TRPs and/or beams may become important. The separate DL transmission information configuration of the respective cells, TRPs, and/or beams may be a main cause of increasing the payload required for DL DCI transmission, which may adversely affect the reception performance of the PDCCH transmitting the DCI. Therefore, in order to support JT, a trade-off between DCI information amount and PDCCH reception performance needs to be considered.

Fig. 11 illustrates an antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to an embodiment of the present disclosure.

Referring to fig. 11, coherent JT (C-JT) supporting coherent precoding between individual cells, TRPs, and/or beams is shown in 11-00. In the case of C-JT, a single data (e.g., PDSCH) may be transmitted from TRP a 11-05 and TRP B11-10, and joint precoding may be performed at multiple TRPs. This means that the same PDSCH may be transmitted from TRP a 11-05 and TRPB 11-10 to the same DMRS port (e.g., DMRS port A, B at both TRPs). In this case, the UE 11-15 may receive DCI information to receive the PDSCH demodulated by the DMRS port A, B.

In fig. 11, NC-JTs supporting non-phase interference coding between individual cells, TRPs and/or beams are shown in 11-20. In the case of NC-JT, PDSCH may be transmitted for each cell, TRP, and/or beam, and separate precoding may be applied for each PDSCH. Since each cell, TRP, and/or beam transmits a different PDSCH, throughput may be improved compared to single cell, TRP, and/or beam transmissions; or the reliability may be improved compared to single cell, TRP and/or beam transmissions due to repeated transmissions of the same PDSCH by individual cells, TRP and/or beams.

Various radio resource allocations for the following occasions can be considered: such as the same timing of time-frequency resources used at the plurality of TRPs for PDSCH transmission in 11-40, the timing of time-frequency resources used at the plurality of TRPs in 11-45 not overlapping each other at all, and the timing of some of the time-frequency resources used at the plurality of TRPs in 11-50 overlapping each other. In the case where the same PDSCH is repeatedly transmitted from a plurality of TRPs at each of the above occasions of radio resource allocation to improve reliability, when the UE does not know whether the PDSCH is repeatedly transmitted, the improvement of reliability may be limited because the UE may not perform combining on the PHY layer of the PDSCH. Accordingly, the present disclosure provides how to instruct and configure duplicate transmissions to improve reliability in NC-JT transmissions.

In order to allocate multiple PDSCH to a UE simultaneously to support NC-JT, various forms, structures, and relationships of DCI may be considered.

Fig. 12 illustrates a configuration of DCI for cooperative communication in a wireless communication system according to an embodiment of the present disclosure.

Specifically, fig. 12 shows four cases of DCI designs for supporting NC-JT.

Referring to fig. 12, case #1 12-00 shows an example when N-1 different PDSCHs are transmitted from other N-1 TRPs (TRP #1 to trp# (N-1)) in addition to PDSCH transmitted from service TRP (TRP # 0), in which case control information of PDSCH transmitted from other TRPs is transmitted in the same DCI format as control information of PDSCH transmitted from service TRP. Specifically, the UE may obtain control information of PDSCH transmitted from different TRPs (TRP #0 to trp# (N-1)) through DCIs (DCI #0 to dci# (N-1)) all having the same DCI format and the same payload. In case #1, the degree of freedom of control (allocation) of each PDSCH is completely safe, but when each DCI is transmitted from a different TRP, reception performance may be degraded due to a difference in coverage of each DCI.

In fig. 12, case #2 12-05 shows an example when N-1 different PDSCHs are transmitted from other N-1 TRPs (TRP #1 to TRP # (N-1)) in addition to PDSCH transmitted from service TRP (TRP # 0), in which case control information of PDSCH transmitted from other TRPs is transmitted in a different DCI format or a different DCI payload than control information of PDSCH transmitted from service TRP. For example, dci#0 carrying control information of PDSCH transmitted from service TRP (trp#0) may include all information elements of DCI format 1_0 to DCI format 1_1, but "shortened" DCI (dci#0 to dci# (N-2)) carrying control information of PDSCH transmitted from cooperative TRP (trp#1 to trp# (N-1)) may include only some information elements of DCI format 1_0 to DCI format 1_1. Accordingly, the sdi carrying control information of the PDSCH transmitted from the cooperative TRP may have a smaller payload than the general DCI (ncui), or include reserved bits lacking the number of bits compared to ncui. In case #2, each PDSCH control (allocation) degree of freedom may be limited according to the content of the information element included in the sdi, but since the reception performance of the sdi is superior to that of the nci, the probability that each sdi has a coverage difference may be reduced.

In fig. 12, case # 3-10 shows another timing when N-1 different PDSCHs are transmitted from other N-1 TRPs (TRP #1 to TRP # (N-1)) in addition to the PDSCH transmitted from the service TRP (TRP # 0), in which case control information of the PDSCH transmitted from the other TRPs is transmitted in a different DCI format or a different DCI payload than the control information of the PDSCH transmitted from the service TRP. For example, control information dci#0 carrying PDSCH transmitted from service TRP (trp#0) may include all information elements of DCI format 1_0 to DCI format 1_1, and control information of PDSCH transmitted from cooperative TRP (trp#1 to trp# (N-1)) may be carried in such a manner that some information elements of DCI format 1_0 to DCI format 1_1 are collected and carried only in "secondary" DCI (sdi). For example, the sdi may include at least one of frequency domain resource allocation, time domain resource allocation, or HARQ related information such as MCS of cooperative TRP. Information not included in the sdi, such as a BWP indicator or a carrier indicator, may follow DCI serving TRP (i.e., dci#0), or normal DCI (ncdci). In case #3, each PDSCH control (allocation) degree of freedom may be limited according to the content of the information element included in the sdi, but compared to case #1 or case #2, the reception performance of the sdi may be controlled and the complexity of DCI blind decoding of the UE may be reduced.

In fig. 12, case # 4-15 shows an example when N-1 different PDSCHs are transmitted from other N-1 TRPs (TRP #1 to TRP # (N-1)) in addition to PDSCH transmitted from service TRP (TRP # 0), in which case control information of PDSCH transmitted from other TRPs is transmitted in the same DCI, long DCI or lci as control information of PDSCH transmitted from service TRP. In this case, the UE obtains control information of PDSCH transmitted from different TRPs (TRP #0 to trp# (N-1)) in a single DCI. In case #4, the DCI blind decoding complexity in the UE does not increase, but the PDSCH control (allocation) degree of freedom decreases, for example, the number of cooperative TRPs is limited due to limitation of the long DCI payload.

In the following description and embodiments of the present disclosure, scdci may refer to various types of auxiliary DCIs carrying control information of PDSCH transmitted from cooperative TRPs, such as shortened DCI, secondary DCI, or general DCI (having the aforementioned DCI formats 1_0 to 1_1), and unless otherwise stated, the description thereof may be similarly applied to various types of auxiliary DCIs.

In the following description and embodiments of the present disclosure, the above case #1, case #2, and case #3, which support NC-JT using one or more DCIs (PDCCHs), are classified as NC-JT based on multiple PDCCHs, and the case #4, which support NC-JT using a single DCI (PDCCH), is classified as NC-JT based on a single PDCCH.

In embodiments of the present disclosure, the term "cooperative TRP" may be replaced with various terms including "cooperative panel" or "cooperative beam" when actually used.

In the embodiments of the present disclosure, for convenience of explanation, the expression "apply NC-JT" is used herein, but various explanations thereof may be made to adapt to the context, such as "UE simultaneously receives one or more PDSCH in one BWP", "UE simultaneously receives PDSCH based on two or more TCI indications in one BWP", "PDSCH received by UE is associated with one or more DMRS port groups", and the like.

In the present disclosure, the radio protocol architecture of NC-JT may be used differently according to TRP development scenarios. For example, when there is no or little backhaul delay between cooperative TRPs, a structure based on MAC layer multiplexing (CA-like method) similar to that shown in 9-10 of fig. 9 may be used. On the other hand, when there is a large backhaul delay between cooperative TRPs (for example, when CSI exchange or scheduling information exchange between cooperative TRPs requires 2ms or more), a separate structure of each TRP from the RLC layer may be used to ensure robustness of the delay (DC-like method).

Second embodiment: method for configuring NC-JT repeated transmission

In the present embodiment of the present disclosure, a specific configuration and indication method for two or more TRPs to repeatedly transmit the same PDSCH in the same transmission band (e.g., component carrier, BWP, etc.) is provided as described in the first embodiment of the present disclosure.

Fig. 13A and 13B illustrate repeated transmission of multiple TRPs using various resource allocation methods in a wireless communication system according to various embodiments of the present disclosure.

That is, fig. 13A and 13B illustrate a case where two or more TRPs repeatedly transmit the same PDSCH.

In the current NR, as many slots as the number of repeated transmissions are required to repeatedly transmit the same PDSCH as described above, and the same cell, TRP, and/or beam is used in each repeated transmission. On the other hand, referring to fig. 13A and 13B, in the embodiments of the present disclosure, in 13-00 and 13-05, repeated transmission is performed using different TRP in each slot to obtain higher reliability. Meanwhile, different retransmission methods may be used depending on the capability of the UE, delay requirements, available resource conditions between TRPs, and the like. For example, when the UE has NC-JT reception capability, each TRP may use a method of transmitting the same PDSCH in the same time-frequency resource, thereby improving frequency resource usage and reducing delay required for PDSCH decoding in 13-10 and 13-15. This method is effective when beams are almost orthogonal to each other and thus beam interference between TRPs involved in simultaneous transmission is small. In another embodiment of the present disclosure, in 13-20 and 13-25, each TRP may use a method of transmitting the same PDSCH in the same time and non-overlapping frequency resources. This approach is effective when beam interference between TRPs involved in simultaneous transmission is large and each TRP has many available frequency resources. In yet another embodiment of the present disclosure, in 13-30 and 13-35, each TRP may use a method of transmitting the same PDSCH in different OFDM symbols of the same slot. This method is effective when each TRP has little available frequency resources and the amount of data to be transmitted is small. In addition, modifications may be made based on the above-described methods.

In the above method, a single DCI may be used to schedule repeated transmissions in 13-00, 13-10, 13-20, and 13-30, and the DCI may indicate a list of all TRPs to be involved in the repeated transmissions. The list of TRPs performing the retransmission may be indicated in the form of a TCI state list, and the length of the TCI state list may be dynamically changed. The DCI may be repeatedly transmitted to improve reliability, and a different beam may be used for each DCI in repeated transmission. Alternatively, multiple DCIs may be used to schedule repeated transmissions in 13-05, 13-15, 13-25, and 13-35, and each DCI may correspond to a PDSCH of a different TRP to be involved in the repeated transmissions. The TRP of each DCI may be indicated in the form of a TCI status. Alternatively, the repeated transmission may be scheduled using shortened DCI, and each of the normal DCI and the secondary DCI may correspond to PDSCH of different TRP to be involved in the repeated transmission. The above-described indication method can be commonly applied to repeated transmission by a plurality of TRPs and different data transmission by a plurality of TRPs.

In NC-JT transmission based on single/multiple/shortened DCI, when a UE does not know whether a PDSCH transmitted from each TRP is repeated data or different data, each PDSCH may be independently decoded, and even if the transmitted PDSCH is repeated, the UE may not perform PDSCH combining, thereby failing to obtain performance advantages. The following example can be considered as a method of determining whether or not retransmission occurs.

A. Method 1: when a specific MCS table is established at an upper layer, for example, when the table is established with, for example, qam LowSE having low spectral efficiency, the UE assumes that each PDSCH transmitted by NC-JT carries the same data, otherwise the UE assumes that each PDSCH transmitted by NC-JT carries different data.

B. Method 2: when one or all of the DCIs of an NC-JT transmission are scrambled by a particular RNTI, e.g., when the DCIs are scrambled by an MCS-C-RNTI, the UE assumes that each PDSCH transmitted by the NC-JT carries the same data, otherwise the UE assumes that each PDSCH transmitted by the NC-JT carries different data.

C. Method 3: when the MCS level indicated in one or all DCIs of NC-JT transmission is below a certain threshold, the UE assumes that each PDSCH transmitted by NC-JT carries the same data, otherwise the UE assumes that each PDSCH transmitted by NC-JT carries different data.

D. Method 4: when the number of DMRS ports, CDM groups, or layers indicated in one DCI of NC-JT transmission is 1, the UE assumes that each PDSCH transmitted by NC-JT carries the same data, otherwise the UE assumes that each PDSCH transmitted by NC-JT carries different data.

E. Method 5: when the HARQ process number indicated in all DCIs transmitted by NC-JT is the same as the NDI value, the UE presumes that each PDSCH transmitted by NC-JT carries the same data, otherwise, the UE presumes that each PDSCH transmitted by NC-JT carries different data. There are the following limitations in current NR: the UE does not expect to receive the PDSCH specified by the specific HARQ process ID until ACK of the PDSCH is transmitted, except for retransmission. The above limitations may be replaced by the following limitations: the UE does not expect to receive PDSCH specified by the specific TCI state except for the specific HARQ process ID until ACK of PDSCH is transmitted. Thus, when one TRP has the same limitations as described above, repeated data transmission between different TRPs is allowed.

The above examples may be operated in combination with two or more examples, and a similar method of determining whether PDSCH transmitted by NC-JT is repeatedly transmitted may be used in addition to these examples.

Meanwhile, in the current NR, the transmission repetition number (or the number of repeated transmissions) is semi-statically set. However, the required level of reliability may be met without repeated transmissions or with a fewer number of repetitions than the set number, depending on, for example, variations in channel conditions. Accordingly, the transmission repetition number can be dynamically set to improve transmission efficiency. For example, when scheduling duplicate transmissions in a single DCI, the number of transmission repetitions may be equal to or proportional to the number of TCI states indicated in the DCI. The value of x may be set dynamically or semi-statically and may be equal to the value in NR designated as the number of transmission repetitions when it is semi-statically set.

When the number of transmission repetitions is greater than the number of TCI states, the TCI states may follow a particular pattern when the TCI states are applied to each repetition slot. For example, when the transmission repetition number is 4 and the TCI state indexes 1 and 2 are indicated, the TCI state may be applied to each transmission slot in a pattern of 1, 2, or 1, 2.

Alternatively, the semi-statically set number of transmission repetitions may be a maximum number of transmission repetitions, and the actual number of transmission repetitions may be dynamically indicated, for example, in DCI/MAC-CE. When the number of transmission repetitions is indicated in the DCI, the number may be indicated in a new field or by redefining an existing field. For example, when a single transmission layer is used only for repeated transmission, a "code point" indicating a plurality of DMRS ports is not used in an antenna port field of DCI, and thus the field may be redefined to indicate the actual transmission repetition number. In another example, the number of transmission repetitions may be set to a value equal to or proportional to the number of TCI states indicated in the DCI/MAC-CE. In yet another example, the number of transmission repetitions may be indicated in a time domain resource allocation field indicated in the DCI. For example, the number of transmission repetitions may be combined with the value indicated in the current NR (e.g., K as described above in connection with fig. 8 ₀ Values of S, L, etc.) are indicated by adding to the values in the time domain resource allocation field of the DCI. Meanwhile, when the repeated transmission is scheduled in a plurality of DCIs, the transmission repetition number may be x, which is equal to or proportional to the number of DCIs scheduled for repeated transmission, and And x may have a value as described above. When the number of transmission repetitions is indicated semi-statically as well as dynamically, there may be a priority order between them. For example, the dynamically indicated number of transmission repetitions may be prioritized over the semi-statically indicated number of transmission repetitions.

Third embodiment: method for configuring retransmission of each time slot using multiple TRPs

The present embodiments of the present disclosure provide various specific methods for supporting repeated transmissions for each slot using multiple TRPs.

First, when the number of transmission repetitions per slot is set in an upper layer, for example, when a PDSCH-aggregation factor is set in PDSCH-Config, and when a plurality of states in DCI scheduling PDSCH indicate a plurality of TRPs, the UE may receive PDSCH by applying respective TCI states to different slots. In this case, there may be one DCI scheduling PDSCH. Meanwhile, in NR, an operation of applying the TCI state to a PDSCH reception time point may be different according to each condition in consideration of time required to decode DCI, as described above in connection with fig. 14.

Fig. 14 illustrates an application of a Transmission Configuration Indicator (TCI) state in a wireless communication system for repeated transmission of each slot by a plurality of TRPs according to an embodiment of the present disclosure.

Condition 1. When DCI 14-00 of the scheduled PDSCH indicates one or more TCI states and a time offset 14-10 between DCI and PDSCH reception time points is equal to or greater than a certain threshold, PDSCH may be received in the TCI state indicated in the DCI.

Condition 2. When DCI 14-00 of the scheduled PDSCH does not indicate a TCI state and a time offset 14-10 between the DCI and a PDSCH reception time point is equal to or greater than a certain threshold, the PDSCH may be received in the TCI state mapped to CORESET 14-05 to which the DCI belongs.

Condition 3. When the time offset 14-10 between DCI and PDSCH reception time points is less than a certain threshold, PDSCH may be received in the TCI state mapped to the lowest CORESET 14-15 monitored at PDSCH reception.

Therefore, in performing repeated transmission per slot using a plurality of TRPs, a method of applying TCI status for each of the above conditions is required. For example, a plurality of TCI states indicated in DCI may be applied to each slot according to one of the following rules.

Rule 1. The indicated respective TCI states are applied to all retransmission slots in sequence. However, for the slot for which condition 3 applies, the indicated TCI state is ignored.

Rule 2. The indicated respective TCI states are sequentially applied to the retransmission slots satisfying the condition 1.

When the number of repeated transmission slots is greater than the indicated number of TCI states, the TCI states may follow a particular pattern when applied to each repeated slot. For example, when the number of repeated transmission slots is 4 and TCI state indexes 1 and 2 are indicated, the TCI state may be applied to each transmission slot in a pattern of 1, 2, or 1, 2. This pattern may be applied to rule 1 or rule 2.

When condition 2 or condition 3 applies to some of the retransmission slots, a single TCI state as before may be applied to all corresponding retransmission slots, or multiple TCI states may be commonly applied to all CORESETs or each CORESET. The rules and TCI state patterns described above may be similarly applied when multiple TCI states are applied to a repeated transmission slot.

In the current NR, the same MCS is applied to repeated transmission of each slot. However, in the repeated transmission of each slot using a plurality of TRPs, the channel between each TRP and the UE may vary greatly, and thus a different MCS needs to be configured for each TRP. In this method, the MCS of the second TRP may be set in the MCS field of the second codeword of the DCI, for example. Since the current NR assumes that the repeated transmission in each slot is transmitted on a single layer, the maximum number of codewords set in the upper layer may be 1. Thus, when repeated transmission per slot is configured and the maximum number of codewords set in the upper layer is 2, and when two or more TCI states are indicated in a single DCI, the UE may interpret the MCS field of the second codeword as the MCS of the second TRP. In this case, the MCS value and RV value of the second codeword may not be set to values disabling the second codeword, for example, mcs=6 and rv=1.

In the current NR, the number of symbols and the symbol positions are the same in the repeated transmission of each slot. However, in repeated transmissions for each slot using multiple TRPs, the traffic conditions and available resources for the various TRPs may be different, and thus it may be useful to configure different symbol numbers and symbol positions for each TRP. In this method, the time domain resource allocation field of the aforementioned DCI may set a different value for each TRP. For example, a resource allocation table for each code point mapped to the time domain resource allocation field of the DCI may be separately configured for each TCI state in an upper layer. Alternatively, the time domain resource allocation field of the DCI may be set separately for each TRP. In this case, the number of TRP or TCI states indicated in the DCI may be dynamically changed, in which case blind decoding is required due to dynamic change in DCI size when the number of time domain resource allocation fields is also dynamically set. Thus, the number of time domain resource allocation fields may be fixed to the semi-statically set number of transmission repetitions or the maximum number of TCI states indicated in the DCI. Time slot offset K in time domain resource allocation field ₀ The 7-10 and/or PDSCH mapping types may be applied to the first TRP, while the remaining TRPs may be ignored. Alternatively, the resource allocation table configured in all time domain resource allocation fields/upper layers may be configured with a common K0 and/or PDSCH mapping type.

Fig. 15 illustrates RV configuration in repeated transmission of each slot by a plurality of TRPs in a wireless communication system according to an embodiment of the present disclosure.

Referring to fig. 15, in the current NR, RV values according to table 7 may be used for repeated transmission of each slot. When the RV value is fully applied and multiple TRPs (e.g., two TRPs in fig. 15) are transmitted in alternate time slots, two TRPs may use different RV values in 15-00. In case that the RV value is fully applied and two TRPs are transmitted in alternate slots, the UE may perform soft combining between PDSCH using the same RV value when the two TRPs use the same RV in 15-05. Performing soft combining may further improve reception reliability when there is significant channel variation between the respective TRP and the UE. In order for different TRPs to use the same RV as described above, expression n m in Table 7od4=i, i=0, 1,2,3 can be redefined as, for exampleOr->Alternatively, n may be redefined as, for example, "transmission occasion of TRP" or "related to TCI state", instead of "transmission occasion".

The above examples may be operated in combination with two or more examples, and although the retransmission of each slot is described in the present embodiment of the present disclosure for convenience of explanation, the embodiments of the present disclosure may be similarly applied to other retransmission configuration methods, for example, a method of performing the retransmission in different OFDM symbols in slots of 13-30 or 13-35, or a method of performing the retransmission in non-overlapping frequency resources of 13-20 or 13-25.

Fig. 16 is a block diagram of a UE in a wireless communication system according to an embodiment of the present disclosure.

Referring to fig. 16, the ue may include transceivers 16-00 and 16-10, and a processing module 16-05 including a memory and a processor. The transceivers 16-00 and 16-10 and the processing module 16-05 may operate according to the aforementioned communication methods of the UE. However, the components of the UE are not limited thereto. For example, the UE may include more or fewer elements than described above. In addition, transceivers 16-00 and 16-10 and processing module 16-05 may be implemented in a single chip.

Transceivers 16-00 and 16-10 may transmit signals to and receive signals from BSs. The signals may include control information and data. To this end, the transceivers 16-00 and 16-10 may include an RF transmitter for up-converting a signal to be transmitted and amplifying the signal, and an RF receiver for low noise amplifying a received signal and down-converting a frequency of the received signal. However, this is merely an example of transceivers 16-00 and 16-10, and the elements of transceivers 16-00 and 16-10 are not limited to RF transmitters and RF receivers.

In addition, the transceivers 16-00 and 16-10 may receive a signal on a wireless channel and output the signal to the processing module 16-05, or transmit a signal output from the processing module 16-05 on a wireless channel.

The processing module 16-05 may store programs and data required for UE operation. In addition, the processing module 16-05 may store control information or data included in signals obtained by the UE. The memory of the processing module 16-05 may include a memory such as Read Only Memory (ROM), random Access Memory (RAM), hard disk, compact disk ROM (CD-ROM), digital Versatile Disk (DVD), or a combination of these storage media.

According to embodiments of the present disclosure, the processing module 16-05 may control a series of processes for operating the UE. In some embodiments of the present disclosure, the processing module 16-05 may control components of the UE such that the UE receives a two-layer DCI including a plurality of PDSCH for simultaneously receiving.

Referring to fig. 17, the bs may include transceivers 17-00 and 17-10, and a processing module 17-05 including a memory and a processor. The transceivers 17-00 and 17-10 and the processing module 17-05 may operate according to the aforementioned communication method of the BS. However, the components of the BS are not limited thereto. For example, the BS may include more or fewer elements than those described above. In addition, transceivers 17-00 and 17-10 and processing module 17-05 may be implemented in a single chip.

Transceivers 17-00 and 17-10 may transmit signals to and receive signals from BSs. The signals may include control information and data. To this end, the transceivers 17-00 and 17-10 may include an RF transmitter for up-converting a signal to be transmitted and amplifying the signal, and an RF receiver for low noise amplifying a received signal and down-converting a frequency of the received signal. However, this is merely an example of transceivers 17-00 and 17-10, and the elements of transceivers 17-00 and 17-10 are not limited to RF transmitters and RF receivers.

In addition, the transceivers 17-00 and 17-10 may receive a signal on a wireless channel and output the signal to the processing module 17-05, or transmit a signal output from the processing module 17-05 on a wireless channel.

The processing module 17-05 may store programs and data required for BS operation. In addition, the processing module 17-05 may store control information or data included in the signal obtained by the BS. The memory of the processing module 17-05 may comprise a memory such as a ROM, RAM, hard disk, CD-ROM, DVD or a combination of these storage mediums.

According to embodiments of the present disclosure, the processing module 17-05 may control a series of processes of operating the BS. In some embodiments of the present disclosure, the processing module 17-05 may control components of the BS to configure and transmit two-layer DCI including allocation information for a plurality of PDSCH.

The methods according to embodiments of the present disclosure described in the claims or specification of the present disclosure may be implemented in hardware, software, or a combination of hardware and software.

When implemented in software, a non-transitory computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the non-transitory computer readable storage medium are configured to be executed by one or more processors in the electronic device. The one or more programs may include instructions that cause the electronic device to perform a method according to the embodiments described in the claims or specification of the present disclosure.

Programs (software modules, software) may be stored in RAM, non-volatile memory including flash memory, ROM, electrically Erasable Programmable ROM (EEPROM), magnetic disk storage, CD-ROM, DVD, or other types of optical storage and/or magnetic tape. Alternatively, the program may be stored in the memory in a combination of some or all of them. The memory may be provided in plural.

The program may also be stored in a connectable storage device accessible through a communication network including the internet, an intranet, a Local Area Network (LAN), a wide area network (WLAN), a Storage Area Network (SAN), or a combination thereof. The storage device may be connected to a device that performs embodiments of the present disclosure through an external port. In addition, a separate storage device in the communication network may be connected to the device that performs the embodiments of the present disclosure.

In the embodiments of the present disclosure, the components are represented in the singular or the plural. However, it should be understood that the singular or plural representation is appropriately selected for ease of explanation, depending on the presented circumstances, the present disclosure is not limited to the singular or plural form of the components. Furthermore, elements in the singular may be represented where plural is in the singular and vice versa.

In addition, the embodiments of the present disclosure may be operated by being combined with each other as necessary. For example, embodiments of the present disclosure and some other embodiments of the present disclosure may be combined to operate a BS and a UE. For example, embodiments of the present disclosure and some other embodiments of the present disclosure may be combined to operate a BS and a UE. Although the embodiments of the present disclosure are provided for the FDD LTE system, modifications of the embodiments of the present disclosure based on the technical concepts of the above embodiments of the present disclosure may also be employed by other systems such as the TDD LTE system, the 5G or NR system, or the like.

While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising:

receiving downlink control information, DCI, from at least one of the transmission reception points, TRP, the DCI comprising first information related to a transmission configuration indication, TCI, state and second information about an antenna port;

identifying whether each of the TRPs repeatedly transmits the same data via a physical downlink shared channel PDSCH based on the number of code division multiplexing CDM groups indicated by the second information about the antenna ports; and

data is received from the TRP based on the identified result.

2. The method of claim 1, wherein the first information related to the TCI state indicates two TCI states in a predefined TCI state list.

3. The method of claim 1, wherein identifying whether each of the TRPs repeatedly transmits the same data via the PDSCH based on the number of CDM groups further comprises:

In case the second information about the antenna port indicates that the number of CDM groups is 1, it is recognized that each of the TRPs repeatedly transmits the same data via the PDSCH.

4. The method of claim 3, wherein a number of TCI states indicated by the first information related to the TCI state is the same as a number of times each of the TRPs repeatedly transmits the same data via the PDSCH.

5. The method of claim 3, wherein the number of times each of the TRPs repeatedly transmits the same data via the PDSCH is indicated by a time domain resource allocation field included in the DCI.

6. The method of claim 3, wherein receiving the data from the TRP further comprises:

in the case where each of the TRPs repeatedly transmits the same data via the PDSCH more than the number of TCI states indicated by the first information related to the TCI states, a predefined pattern associated with the TCI states is applied to a slot in which the same data is received from the TRP.

7. The method of claim 6, wherein applying the predefined pattern to the time slot further comprises:

Applying a first TCI state and a second TCI state to a first time slot and a second time slot, respectively, of the time slots, with the first mode activated; and applying the first and second TCI states to a third and fourth one of the time slots, respectively; and

applying a first TCI state to a first and a second one of the time slots with the second mode activated; and applying the second TCI state to a third slot and a fourth slot of the slots.

8. The method of claim 1, wherein identifying whether each of the TRPs repeatedly transmits the same data via the PDSCH based on the number of CDM groups further comprises:

in case the second information about the antenna port indicates that the number of CDM groups is 2, each of the TRPs is identified to transmit different data via the PDSCH.

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

a transceiver; and

at least one processor configured to:

controlling the transceiver to receive downlink control information, DCI, from at least one of the transmission reception points, TRP, the DCI comprising first information related to a transmission configuration indication, TCI, status and second information about antenna ports,

Identifying whether each of the TRPs repeatedly transmits the same data via a physical downlink shared channel PDSCH based on the number of code division multiplexing CDM groups indicated by the second information about the antenna port, and

controlling the transceiver to receive data from the TRP based on the identified result.

10. The terminal of claim 9, wherein the first information related to the TCI state indicates two TCI states in a predefined TCI state list.

11. The terminal of claim 9, wherein the at least one processor is further configured to:

12. The terminal of claim 11, wherein a number of TCI states indicated by the first information related to the TCI state is the same as a number of times each of the TRPs repeatedly transmits the same data via the PDSCH, and

wherein the number of times that each of the TRPs repeatedly transmits the same data via the PDSCH is indicated by a time domain resource allocation field included in the DCI.

13. The terminal of claim 11, wherein the at least one processor is further configured to:

14. The terminal of claim 13, wherein the at least one processor is further configured to:

applying a first and a second TCI state to a first and a second one of the time slots, respectively, and applying the first and the second TCI state to a third and a fourth one of the time slots, respectively, with the first mode activated, and

in the case where the second mode is activated, a first TCI state is applied to a first and second slot of the slots, and a second TCI state is applied to a third and fourth slot of the slots.

15. The terminal of claim 9, wherein the at least one processor is further configured to: