Patent Description:
To meet the ever-increasing demand with respect to wireless data traffic since the commercialization of the <NUM> communication system, there have been efforts to develop an advanced fifth generation (<NUM>) system or pre-<NUM> communication system. For this reason, the <NUM> or pre-<NUM> communication system is also called a beyond 4th-generation (<NUM>) network communication system or post long term evolution (LTE) system. Implementation of the <NUM> communication system using ultrahigh frequency (millimeter wave (mmWave)) bands, e.g., <NUM> giga hertz (GHz) bands, is being considered to attain higher data transfer rates. To reduce propagation loss of radio waves and increase a transmission range of radio waves in the ultrahigh frequency bands, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large-scale antenna techniques are under discussion. To improve system networks, technologies for advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device to device (D2D) communication, wireless backhaul, moving networks, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like are also being developed in the <NUM> communication system. In addition, in the <NUM> system, an advanced coding modulation (ACM), e.g., hybrid FSK and QAM modulation (FQAM), sliding window superposition coding (SWSC), and an advanced access technology, e.g., filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SCMA) are being developed.

In the meantime, the Internet is evolving from a human-oriented connectivity network where humans generate and consume information to an Internet of things (IoT) network where distributed entities or things send, receive and process information without human intervention. Internet of Everything (IoE) technologies, in which a big data processing technology through connection with a cloud server, for example, is combined with the loT technology, have also emerged. To implement loT, various technologies, such as a sensing technology, a wired/wireless communication and network infrastructure, a service interfacing technology, and a security technology are required, and even technologies for sensor networks, machine to machine (M2M) communication, machine type communication (MTC) for connection between things are being studied these days. In the loT environment, intelligent Internet technology (IT) services that create new values for human life by collecting and analyzing data generated from connected things may be provided. loT may be applied to a variety of areas, such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart home appliances and advanced medical services through convergence and combination between existing information technologies (IT) and various industrial applications.

In this regard, various attempts to apply the <NUM> communication system to the loT network are being made. For example, technologies regarding sensor network, M2M, MTC, etc., are implemented by the <NUM> communication technologies, such as beamforming, MIMO, and array antenna schemes, etc. Even application of a cloud radio access network (cloud RAN) as the aforementioned big data processing technology may be an example of convergence of <NUM> and loT technologies.

<CIT> describes a method of performing a bandwidth part (BWP) operation in a wireless communication system. Specifically, the method performed by a terminal includes receiving a first message including information related to at least one initial BWP configuration from a network, receiving a second message including configuration information for an additional BWP from the network, receiving downlink control information (DCI) related to BWP switching for at least one configured BWP from the network, and transmitting and receiving signals to and from the network in an activated BWP based on the received DCI.

According to <CIT>, the pre-configuration of a grant of a non-active bandwidth part (BWP) or other wireless resource may be beneficial to reduce signaling overhead. A base station may not need to transmit a DCI to activate a configured grant if the configured grant on a non-active BWP is activated based on switching an active BWP to a pre-configured BWP. If a configured grant on a non-active BWP is activated, a base station may not need to transmit a DCI on a new active BWP for a resource grant. A wireless device may receive a DCI indicating a switch an active BWP from a first BWP to a second BWP for a particular cell. The configured grants may be type <NUM> grant-free transmission that may not need activation signaling. The activation and/or deactivation of the one or more configured grants may depend on the state of the second BWP.

A technical objective of the disclosure is to provide a method and apparatus for configuring a bandwidth part (BWP) resource for efficient uplink or downlink transmission or reception for various services in a mobile communication system.

Embodiments of the disclosure provide a method and apparatus for configuring a bandwidth part (BWP) resource for efficient uplink or downlink transmission or reception in a mobile communication system.

According to an embodiment of the disclosure, a method performed by a user equipment (UE) in a wireless communication system includes receiving resource configuration information in a time domain for an uplink (UL) or a downlink (DL) in a plurality of bandwidth parts (BWPs) from a base station (BS); receiving information about an activated BWP from the BS; determining a UL resource or a DL resource in the time domain corresponding to the activated BWP based on the resource configuration information and the information about the activated BWP; and communicating with the BS based on the UL resource or the DL resource of the time domain corresponding to the activated BWP.

According to an embodiment of the disclosure, a method performed by a BS in a wireless communication system includes transmitting resource configuration information in a time domain for UL or DL in a plurality of bandwidth parts (BWPs) to a UE; transmitting information about an activated BWP to the UE; and communicating with the UE based on a UL resource or a DL resource in the time domain corresponding to the activated BWP determined according to the resource configuration information and the information about the activated BWP.

Embodiments of the disclosure will be described in detail with reference to accompanying drawings.

Technological content well-known in the art or not directly related to the disclosure is omitted in the following description. Through the omission of content that might otherwise obscure the subject matter of the disclosure, the subject matter will be understood more clearly.

For the same reason, some parts in the accompanying drawings are exaggerated, omitted or schematically illustrated. The size of the respective elements may not fully reflect their actual size. In the drawings, the same or corresponding elements are denoted by the same reference numerals.

Advantages and features of the disclosure, and methods for achieving them will be understood more clearly when the following embodiments are read with reference to the accompanying drawings. The embodiments of the disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments of the 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 of ordinary skill in the art. Like numbers refer to like elements throughout the specification. In the description of the disclosure, when it is determined that a detailed description of related functions or configurations may unnecessarily obscure the subject matter of the disclosure, the detailed description will be omitted. Further, the terms, as will be mentioned later, are defined by taking functionalities in the disclosure into account, but may vary depending on practices or intentions of users or operators. Accordingly, the terms should be defined based on descriptions throughout this 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 a gNB, an eNB, a Node B, a base station (BS), a radio access unit, a base station controller, or a network node. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. Herein, downlink (DL) refers to a radio transmission path for a signal transmitted from a BS to a UE, and uplink (UL) refers to a radio transmission path for a signal transmitted from a UE to a BS. Although the following embodiments will focus on the long term evolution (LTE) or LTE-Advanced (LTE-A) system as an example, they may be applied to other communication systems with similar technical backgrounds or channel types. For example, the 5th generation (<NUM>) mobile communication technologies developed since the LTE-A, such as the <NUM> new radio (NR) may be included in the systems to which the embodiments of the disclosure will be applied, and the term '<NUM>' as herein used may be a concept including the existing LTE, LTE-A, or other similar services. Furthermore, embodiments of the disclosure will also be applied to different communication systems with some modifications to such an extent that does not significantly deviate the scope of the disclosure when judged by skilled people in the art.

It will be understood that each blocks and combination of the blocks of a flowchart may be performed by computer program instructions. The computer program instructions may be loaded on a processor of a universal computer, a special-purpose computer, or other programmable data processing equipment, and thus they generate means for performing functions described in the block(s) of the flowcharts when executed by the processor of the computer or other programmable data processing equipment. The computer program instructions may also be stored in computer-executable or computer-readable memories oriented for computers or other programmable data processing equipment, such that the instructions stored in the computer-executable or computer-readable memory may manufacture a product that contains instruction means for performing functions described in the block(s) of the flowchart. The computer program instructions may also be loaded on computers or programmable data processing equipment, so it is possible for the instructions to generate a process to be executed by the computer or the other programmable data processing equipment to provide operations for performing functions described in the block(s) of the flowchart.

Furthermore, each block may represent a part of a module, segment, or code including one or more executable instructions to perform particular logic function(s). It is noted that the functions described in the blocks may occur out of order in some alternative embodiments. For example, two successive blocks may be performed substantially at the same time or in reverse order depending on the corresponding functions.

The term "module" (or sometimes "unit") as used herein refers to a software or hardware component, such as field programmable gate array (FPGA) or application specific integrated circuit (ASIC), which performs some functions. However, the module is not limited to software or hardware. The module may be configured to be stored in an addressable storage medium, or to execute one or more processors. For example, the modules may include components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program codes, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables. Functions served by components and modules may be combined into a smaller number of components and modules, or further divided into a larger number of components and modules. Moreover, the components and modules may be implemented to execute one or more central processing units (CPUs) in a device or security multimedia card. In embodiments, the module may include one or more processors.

Embodiments of the disclosure will now be described in detail with reference to the accompanying drawings. A method and apparatus proposed in the embodiments of the disclosure are described by taking an example of a service to enhance coverage, without being limited thereto, and a combination of all or some of one or more embodiments of the disclosure may be used for a method of transmitting or receiving a data channel, a control channel or a reference signal corresponding to an additional service. Furthermore, the embodiments of the disclosure will also be applied through some modifications to an extent that does not significantly deviate from the scope of the disclosure when judged by those of ordinary skill in the art.

In the description of the disclosure, when it is determined that a detailed description of related functions or configurations may unnecessarily obscure the subject matter of the disclosure, the detailed description will be omitted. Further, the terms, as will be mentioned later, are defined by taking functionalities in the disclosure into account, but may vary depending on practices or intentions of users or operators. Accordingly, the terms should be defined based on descriptions throughout this specification.

Wireless communication systems are evolving from early systems that provide voice-oriented services to broadband wireless communication systems that provide high data rate and high quality packet data services such as third generation partnership project (3GPP) high speed packet access (HSPA), LTE or evolved universal terrestrial radio access (E-UTRA), LTE-A, LTE-Pro, 3GPP2 high rate packet data (HRPD), ultra-mobile broadband (UMB), and IEEE <NUM>. 16e communication standards.

As a representative example of such a broadband wireless communication system, an LTE system adopts orthogonal frequency division multiplexing (OFDM) for DL and single carrier frequency division multiple access (SC-FDMA) for UL. The UL refers to a radio link for a UE or MS to transmit data or a control signal to an eNode B (eNB) or BS, and the DL refers to a radio link for a BS to transmit data or a control signal to a UE or MS. Such a multiple-access scheme allocates and operates time-frequency resources for carrying data or control information for respective users not to overlap each other, i.e., to maintain orthogonality, thereby identifying each user's data or control information.

The <NUM> communication system that is a communication system since the LTE, needs to support services that simultaneously meet various demands to freely reflect the various demands from users and service providers. The services considered for the <NUM> communication system may include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), ultra-reliability low latency communication (URLLC), etc..

The eMBB is aimed at providing more enhanced data rates than the LTE, LTE-A or LTE-Pro may support. For example, in the <NUM> communication system, the eMBB is required to provide <NUM> Gbps peak data rate in DL and <NUM> Gbps peak data rate in UL in light of a single BS. Furthermore, the <NUM> communication system needs to provide increasing user perceived data rate while providing the peak data rate. To satisfy these requirements, enhancement of various technologies for transmission or reception including multiple-input multiple-output (MIMO) transmission technologies may be required. While the LTE system uses a maximum of <NUM> transmission bandwidth in the <NUM> band for signal transmission, the <NUM> communication system may use frequency bandwidth wider than <NUM> in the <NUM> to <NUM> band or in the <NUM> or higher band, thereby satisfying the data rate required by the <NUM> communication system.

A bandwidth part (BWP) technology for the BS to divide the entire carrier frequency band into multiple frequency bands that may be served by respective UEs when the BS supports wideband frequencies. In other words, when the BS supports a BWP and a particular UE has a small BW capability, the BS may provide a small frequency band for the UE through the BWP and may reduce energy consumption of the UE by reducing the frequency band through BWP switching. In addition, it has an effect of being able to support various services without latency to one UE through BWP switching while providing a different frame structure to each of multiple BWPs. The BWP technology may be applied to a one-to-one control channel or data channel between a certain UE and the BS. Furthermore, the BS may apply it for reducing energy of the BS by transmitting a control channel and a data channel for transmitting a common signal to be transmitted to multiple UEs in the system, e.g., a synchronization signal, a physical broadcast channel (PBCH) or system information, only in a configured BWP.

At the same time, in the <NUM> communication system, mMTC is considered to support an application service such as the Internet of Things (IoT). In order for the mMTC to provide the loT efficiently, support for access from massive number of UEs in a cell, enhanced coverage of the terminal, extended battery time, cost reduction of the terminal, etc., are required. Because the loT is equipped in various sensors and devices to provide communication functions, it may be supposed to support a large number of UEs in a cell (e.g., <NUM>,<NUM>,<NUM> terminals/km<NUM>). Furthermore, a UE supporting the mMTC is more likely to be located in a shadow area, such as basement of a building, which might not be covered by a cell by the nature of the service, so the mMTC requires an even larger coverage than expected for other services provided by the <NUM> communication system. The UE supporting the mMTC needs to be a low-cost UE, and requires quite long battery life time such as <NUM> to <NUM> years because the battery in the UE is hard to be changed frequently.

Finally, URLLC is a mission critical cellular-based wireless communication service. For example, the URLLC may provide services used for remote control over robots or machinery, industrial automation, unmanned aerial vehicle, remote health care, emergency alert, etc. Accordingly, communication offered by the URLLC requires very low latency and very high reliability. For example, URLCC services may need to satisfy sub-millisecond (less than <NUM> millisecond) air interface latency and simultaneously require a packet error rate equal to or lower than <NUM>-<NUM>. Hence, for the URLLC services, the <NUM> system needs to provide a smaller transmit time interval (TTI) than for other services, and simultaneously needs to allocate a wide range of resources for a frequency band to secure reliability of the communication link.

Those three services of the <NUM> communication system (hereinafter, interchangeably used with the <NUM> system), i.e., eMBB, URLLC, and mMTC, may be multiplexed and transmitted from a single system. In this case, to meet different requirements for the three services, different transmission or reception schemes and parameters may be used between the services.

A frame structure in a <NUM> system will now be described in more detail with reference to the accompanying drawings.

<FIG> illustrates a basic structure of time-frequency domain, which is a radio resource domain of a <NUM> system, according to an embodiment of the disclosure.

In <FIG>, the horizontal axis represents a time domain, and the vertical axis represents a frequency domain. A basic resource unit in the time and frequency domain is a resource element (RE) <NUM>, which may be defined as an orthogonal frequency division multiplexing (OFDM) symbol or discrete Fourier transform spread OFDM (DFT-s-OFDM) <NUM> in the time domain and a subcarrier <NUM> on the frequency domain. In the frequency domain, <MAT> (e.g., <NUM>) consecutive REs may constitute a single resource block (RB) <NUM>. In the time domain, <MAT> consecutive OFDM symbols may constitute a single subframe <NUM>.

<FIG> illustrates a slot structure considered in a <NUM> system, according to an embodiment of the disclosure.

In <FIG>, an example of structures of a frame <NUM>, a subframe <NUM> and a slot <NUM> are shown. The one frame <NUM> may be defined to be <NUM> long. The one subframe <NUM> may be defined to be <NUM>, and thus a total of <NUM> subframes <NUM> may constitute the one frame <NUM>. The one slot <NUM> or <NUM> may be defined to have <NUM> OFDM symbols (i.e., the number of symbols per <NUM> slot ( <MAT>). The one subframe <NUM> may include one or multiple slots <NUM> and <NUM>, and the number of slots <NUM> and <NUM> per one subframe may vary depending on subcarrier spacing configuration values µ <NUM> or <NUM>.

In the example of <FIG>, slot structures are shown in cases of the subcarrier spacing configuration values being <NUM> and <NUM>, i.e., µ=<NUM> (<NUM>) and µ=<NUM>(<NUM>), respectively. In the case of µ=<NUM> (<NUM>), the one subframe <NUM> includes one slot <NUM>, and in the case of µ=<NUM> (<NUM>), the one subframe <NUM> includes two slots <NUM>. That is, depending on the subcarrier spacing configuration value µ, the number of slots per one subframe ( <MAT>) may vary and the number of slots per one frame ( <MAT>) may vary accordingly. <MAT> and <MAT> depending on the subcarrier spacing configuration value µ may be defined as in Table <NUM> below.

In the <NUM> wireless communication system, synchronization signal block (SSB) (interchangeably used with SS block, SS/PBCH block, etc.) may be transmitted for initial access, and the SSB may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). In an initial access step in which the UE accesses the system for the first time, the UE may first obtain DL time and frequency domain synchronization from a synchronization signal through cell search and then obtain a cell identity (ID). The synchronization signal may include a PSS and an SSS. The UE may then receive a PBCH that carries a master information block (MIB) from the BS to obtain transmission or reception related system information such as system bandwidth or associated control information, and basic parameter values. Based on this information, the UE may obtain a system information block (SIB) by decoding a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH). After this, the UE exchanges IDs with the BS through a random access operation, and makes initial access to the network through operations of registration, authentication, etc..

An initial cell access operation procedure of a <NUM> communication system will now be described in more detail with reference to the accompanying drawings.

The synchronization signal is a signal to be a reference for cell search and may be transmitted with subcarrier spacing applied thereto, which is suitable to a channel condition such as phase noise for each frequency band. A <NUM> BS may transmit multiple synchronization signal blocks based on the number of analog beams intended for operation. The PSS and the SSS may be mapped and transmitted over <NUM> RBs, and the PBCH may be mapped and transmitted over <NUM> RBs. A structure in which the synchronization signal and the PBCH are transmitted in the <NUM> communication system will now be described.

<FIG> illustrates an SSB considered in a <NUM> communication system.

In <FIG>, an SSB <NUM> may be comprised of a PSS <NUM>, an SSS <NUM>, and a PBCH <NUM>.

As illustrated, the SSB <NUM> may be mapped to four OFDM symbols <NUM> in the time domain. The PSS <NUM> and the SSS <NUM> may be transmitted in <NUM> RBs <NUM> in the frequency domain, and first and third OFDM symbols, respectively, in the time domain. In the <NUM> system, a total of <NUM> different cell IDs may be defined, and the PSS <NUM> may have three different values based on the cell's physical layer ID and the SSS <NUM> may have <NUM> different values. Upon detection of the PSS <NUM> and the SSS <NUM>, the UE may obtain one of <NUM> cell IDs as a combination of the PSS <NUM> and the SSS <NUM>. The cell ID obtained by the UE may be expressed in Equation <NUM> below: <MAT>.

In Equation <NUM>, N(<NUM>)ID may be estimated from the SSS <NUM>, and may have a value between <NUM> to <NUM>. N(<NUM>)ID may be estimated from the PSS <NUM>, and may have a value between <NUM> to <NUM>. The cell ID NcellID may be estimated in a combination of N(<NUM>)ID and N(<NUM>)ID.

The PBCH <NUM> may be transmitted on resources including <NUM> RBs <NUM> in the frequency domain and <NUM> RBs <NUM> and <NUM> on either side of the second to fourth OFDM symbols of the SSB in the time domain while the SSS <NUM> is transmitted in the middle <NUM> RBs. Various system information called an MIB may be transmitted in the PBCH <NUM>, and more particularly, the MIB may include information as in Table <NUM> below and a PBCH payload and a PBCH demodulation reference signal (DMRS) may include additional information as will be described at a later time.

As transmission bandwidth, <NUM> RBs, <NUM> of the PSS <NUM> and the SSS <NUM> and transmission bandwidth, <NUM> RBs, <NUM> of the PBCH <NUM> are different, there are six RBs on either side <NUM> and <NUM> in the first OFDM symbol aside from twelve RBs in the middle where the PSS <NUM> is transmitted, which may be used to transmit other signals or emptied.

The SSB may all be transmitted by using the same analog beam. That is, the PSS <NUM>, the SSS <NUM>, and the PBCH <NUM> may all be transmitted in the same beam. An analog beam has characteristics of not being applied differently in the frequency domain, and in all RBs in the frequency domain in a particular OFDM symbol in which a particular analog beam is applied, the same analog beam is applied. That is, four OFDM symbols in which the PSS <NUM>, the SSS <NUM>, and the PBCH <NUM> are transmitted may all be transmitted in the same analog beam.

<FIG> illustrates cases where SSBs are transmitted in a frequency band below <NUM> considered in a <NUM> communication system.

Referring to <FIG>, subcarrier spacing (SCS) of <NUM> <NUM> and SCS of <NUM> <NUM> and <NUM> may be used for SSB transmission in frequency bands below <NUM> in the <NUM> communication system. A transmission case, case #<NUM><NUM> for the SSB may have <NUM> SCS, and two transmission cases, case #<NUM><NUM> and case #<NUM><NUM> for the SSB may have <NUM> SCS.

In case #<NUM><NUM> with the SCS of <NUM> <NUM>, up to two SSBs may be transmitted in a time of <NUM> <NUM> (corresponding to a length of one slot when the one slot is comprised of <NUM> OFDM symbols). In the example of <FIG>, SSB #<NUM><NUM> and SSB #<NUM><NUM> are illustrated. In this case, SSB #<NUM><NUM> may be mapped to four consecutive symbols from the third OFDM symbol, and SSB #<NUM><NUM> may be mapped to four consecutive symbols starting from the ninth OFDM symbol.

Different analog beams may be applied to SSB #<NUM><NUM> and SSB #<NUM><NUM>. Accordingly, a beam may be applied to all of the third to sixth OFDM symbols to which SSB #<NUM><NUM> is mapped, and another beam may be applied to all of the ninth to twelfth OFDM symbols to which SSB #<NUM><NUM> is mapped. Which beam is to be used for <NUM>-th, <NUM>-th, <NUM>-th, and <NUM>-th OFDM symbols to which no SSB is mapped may be freely determined by the BS.

In case #<NUM><NUM> with the SCS of <NUM> <NUM>, up to two SSBs may be transmitted in a time of <NUM> <NUM> (corresponding to a length of one slot when the one slot is comprised of <NUM> OFDM symbols), and accordingly, up to four SSBs may be transmitted in a time of <NUM> (corresponding to a length of two slots when the one slot is comprised of <NUM> OFDM symbols). In the example of <FIG>, illustrated is an occasion when SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, and SSB #<NUM><NUM> are transmitted in <NUM> (i.e., in two slots). In this case, the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped from the fifth OFDM symbol and the ninth OFDM symbol of the first slot, respectively, and the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped from the third OFDM symbol and the seventh OFDM symbol of the second slot, respectively.

Different analog beams may be applied to the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, and the SSB #<NUM><NUM>. In other words, an identical analog beam may be applied to the fifth to eighth OFDM symbols of the first slot in which the SSB #<NUM><NUM> is transmitted, another identical analog beam may be applied to the ninth to twelfth OFDM symbols of the first slot in which the SSB #<NUM><NUM> is transmitted, another identical analog beam may be applied to the third to sixth OFDM symbols of the second slot in which the SSB #<NUM><NUM> is transmitted, and another identical analog beam may be applied to the seventh to tenth OFDM symbols of the second slot in which the SSB #<NUM><NUM> is transmitted may be applied. Which beam is to be used for OFDM symbols to which no SSB is mapped may be freely determined by the BS.

In case #<NUM><NUM> with the SCS of <NUM> <NUM>, up to two SSBs may be transmitted in a time of <NUM> <NUM> (corresponding to a length of one slot when the one slot is comprised of <NUM> OFDM symbols), and accordingly, up to four SSBs may be transmitted in a time of <NUM> (corresponding to a length of two slots when the one slot is comprised of <NUM> OFDM symbols). In the example of <FIG>, illustrated are SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, and SSB #<NUM><NUM> transmitted in <NUM> (i.e., in two slots). In this case, the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped from the third OFDM symbol and the ninth OFDM symbol of the first slot, respectively, and the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped from the third OFDM symbol and the ninth OFDM symbol of the second slot, respectively.

Different analog beams may be used for the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, and the SSB #<NUM><NUM>. As described above, an identical beam may be used in four OFDM symbols in which each SSB is transmitted, and which beam is to be used in OFDM symbols to which no SSB is mapped may be freely determined by the BS.

<FIG> illustrates cases where SSBs are transmitted in frequency bands above <NUM> considered in a <NUM> communication system.

Referring to <FIG>, SCS of <NUM> <NUM> and SCS of <NUM> <NUM> may be used for SSB transmission in frequency bands above <NUM> in the <NUM> communication system.

In case #<NUM><NUM> with the SCS of <NUM> <NUM>, up to four SSBs may be transmitted in a time of <NUM> <NUM> (corresponding to a length of two slots when the one slot is comprised of <NUM> OFDM symbols). In the example of <FIG>, illustrated is an occasion when SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, and SSB #<NUM><NUM> are transmitted in <NUM> (i.e., in two slots). In this case, the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped from the fifth OFDM symbol and the ninth OFDM symbol of the first slot, respectively, and the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped from the third OFDM symbol and the seventh OFDM symbol of the second slot, respectively.

In the same way as described above, different analog beams may be used for the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, and the SSB #<NUM><NUM>. An identical beam may be used in four OFDM symbols in which each SSB is transmitted, and which beam is to be used in OFDM symbols to which no SSB is mapped may be freely determined by the BS.

In case #<NUM><NUM> with the SCS of <NUM> <NUM>, up to <NUM> SSBs may be transmitted in a time of <NUM> <NUM> (corresponding to a length of four slots when one slot is comprised of <NUM> OFDM symbols). In the example of <FIG>, illustrated is an occasion when SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, SSB #<NUM><NUM>, and SSB#<NUM><NUM> are transmitted in <NUM> (i.e., in four slots). In this case, the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped to the ninth OFDM symbol and the thirteenth OFDM symbol of the first slot, respectively, the SSB #<NUM><NUM> and the SSB #<NUM><NUM> may be mapped to the third OFDM symbol and the seventh OFDM symbol of the second slot, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, and the SSB #<NUM><NUM> may be mapped to the fifth OFDM symbol, ninth OFDM symbol, and the thirteenth OFDM symbol of the third slot, respectively, and the SSB #<NUM><NUM> may be mapped to the third OFDM symbol of the fourth slot.

In the same way as described above, different analog beams may be used for the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, the SSB #<NUM><NUM>, and the SSB #<NUM><NUM>. An identical beam may be used in four OFDM symbols in which each SSB is transmitted, and which beam is to be used in OFDM symbols to which no SSB is mapped may be freely determined by the BS.

<FIG> illustrates cases where SSBs are transmitted with SCS of less than <NUM>. In the <NUM> communication system, SSBs may be periodically transmitted at an interval of <NUM> (corresponding to five frames or a half frame <NUM>).

In a frequency band below <NUM>, up to four SSBs may be transmitted in the time of <NUM> <NUM>. In a frequency band above <NUM> and below <NUM>, up to eight may be transmitted. In a frequency band above <NUM>, up to sixty four may be transmitted. As described above, <NUM> and <NUM> of SCS may be used at frequencies below <NUM>.

In an example of <FIG>, as case #<NUM><NUM> with <NUM> of SCS comprised of one slot of <FIG> may be mapped to the first slot and the second slot in the frequency band below <NUM>, up to four <NUM> may be transmitted, and as it may be mapped to the first, second, third, and fourth slots in the frequency band above <NUM> and below <NUM>, up to eight <NUM> may be transmitted. As case #<NUM><NUM> or case #<NUM><NUM> with <NUM> of SCS comprised of two slots of <FIG> may start to be mapped from the first slot in the frequency band below <NUM>, up to four <NUM> and <NUM> may be transmitted, and as it may start to be mapped from the first and third slots in the frequency band above <NUM> and below <NUM>, up to eight <NUM> and <NUM> may be transmitted.

<NUM> and <NUM> of SCS may be used in the frequency band above <NUM>. In an example of <FIG>, as case #<NUM><NUM> with <NUM> of SCS comprised of two slots of <FIG> may start to be mapped from 1st, 3rd, 5th, 7th, 11th, 13th, 15th, 17th, 21st, 23rd, 25th, 27th, 31st, 33rd, 35th and 37th slots in the frequency band above <NUM>, up to <NUM><NUM> may be transmitted. In an example of <FIG>, as case #<NUM><NUM> with <NUM> of SCS comprised of four slots of <FIG> may start to be mapped from 1st, 5th, 9th, 13th, 21st, 25th, 29th, and 33rd slots in the frequency band above <NUM>, up to <NUM><NUM> may be transmitted.

SSB indication information included in the system and actually transmitted will now be described in detail with reference to <FIG>. As described above, the SSB indication information actually transmitted may be obtained from system information called an SIB, or obtained even through higher layer signaling. The SSB indication information included in the system information and actually transmitted may be indicated in <NUM> bits to represent whether up to eight SSBs are transmitted in the frequency band below <NUM>, and may be indicated in a total of <NUM> bits to represent whether up to <NUM> SSBs <NUM> are transmitted in the frequency band above <NUM>. Specifically, in the frequency band below <NUM>, one bit may indicate whether one SSB is transmitted. When the first MSB is '<NUM>', it may indicate that the first SSB is actually transmitted from the BS, and when it is '<NUM>', it may indicate that the first SSB is not transmitted from the BS.

<FIG> illustrates an occasion when an SSB is transmitted with <NUM> of SCS in a frequency band above <NUM>.

Referring to <FIG>, to represent whether up to <NUM> SSBs are transmitted in a frequency band above <NUM>, <NUM> SSBs may be grouped into one, so <NUM> SSBs may be divided into <NUM> groups <NUM> to <NUM>. Hence, a total of <NUM> bits, <NUM> bits <NUM> of which indicate whether <NUM> SSBs in one group are transmitted and <NUM> bits <NUM> of which indicate whether there are <NUM> groups, may indicate whether all of the SSBs are transmitted. The <NUM> bits indicating whether transmission is made for one group may represent a pattern <NUM> in the same way as the aforementioned frequency band below <NUM>. Specifically, when the first MSB is '<NUM>', it indicates that the first SSB is transmitted <NUM> from the BS, and when the second MSB is '<NUM>', it indicates that the second SSB is not actually transmitted <NUM> from the BS. For the <NUM> bits <NUM> indicating whether there are <NUM> groups, when the first MSB is '<NUM>'(<NUM>), it indicates that <NUM> SSBs in the first group, Group# <NUM>, are not transmitted altogether (<NUM>). When the second MSB is '<NUM>', it indicates that <NUM> SSBs in the second group, Group#<NUM><NUM>, are transmitted (<NUM>) in a transmission pattern <NUM> of <NUM> consecutive SSBs in the configured one group. The actually transmitted SSB indication information transmitted not by system information but by higher layer signaling may be indicated in a total of <NUM> bits, each bit indicating whether one SSB is transmitted, thereby representing whether up to <NUM> SSBs are each transmitted regardless of the frequency band.

The UE may obtain the SIB by decoding the PDCCH and PDSCH based on system information included in the received MIB. The SIB may include one of at least UL cell bandwidth, a random access parameter, a paging parameter, a UL power control related parameter, etc. The UE may establish a radio link with the network through a random access procedure based on system information and synchronization with the network obtained in a cell search procedure. Random access may be used in a contention-based method or a contention-free method. The contention-based access method may be used for the purpose of e.g., the UE performing cell selection and re-selection in an initial cell access step or the UE going into an RRC_connected state from an RRC_idle state. The contention-free random access may be used to re-establish UL synchronization in case of DL data arrival, handover, or location measurement.

A <NUM>-step random access procedure (or <NUM>-step RACH procedure) will now be described in detail with reference to <FIG> illustrates a <NUM>-step random access procedure. Referring to <FIG>, in a first step <NUM> of the random access procedure, the UE may transmit a random access preamble (or message <NUM>) to the BS (or gNB). The BS may then measure a transmission delay between the UE and the BS and may be UL synchronized. In this case, the UE may transmit the random access preamble selected arbitrarily from a random access preamble set given in advance by the system information. Initial transmission power of the random access preamble may be determined based on a path loss between the BS and the UE, which is measured by the UE. Furthermore, the UE may determine a transmission beam direction (or transmission beam or beam) of the random access preamble based on a synchronization signal (or an SSB) received from the BS, and transmit the random access preamble by applying the determined transmission beam direction.

In a second step <NUM>, the BS may transmit, to the UE, a random access response (RAR) (or message <NUM>) to a detected random access attempt. The BS may transmit, to the UE, a UL transmission timing control command from a transmission delay measured from the random access preamble received in the first step. The BS may also transmit, to the UE, a UL resource and power control command to be used by the UE in scheduling information. The scheduling information may include control information about the UL transmission beam of the UE. The RAR is transmitted in a PDSCH and includes the following information:.

When the UE fails to receive the RAR, which is scheduling information for message <NUM> in the second step <NUM>, the procedure proceeds back to the first step <NUM>. When the procedure proceeds back to the first step, the UE increases transmission power of the random access preamble by a certain step (which is called power ramping) for transmission, thereby increasing a chance of receiving the random access preamble at the BS.

In the third step <NUM>, the UE may transmit, to the BS, UL data (scheduled transmission or message <NUM>) including its UE ID in a UL data channel (physical uplink shared channel (PUSCH)) by using a UL resource allocated in the second step <NUM>. Transmission timing of the UL data channel to transmit the message <NUM> follows the UL transmission timing control command received from the BS in the second step <NUM>. Furthermore, transmission power of the UL data channel to transmit the message <NUM> is determined by taking into account a power ramping value of the random access preamble and power control command received from the BS in the second step <NUM>. The UL data channel to transit the message <NUM> is a first UL data signal transmitted by the UE to the BS after the UE transmits the random access preamble.

Finally, in the fourth step <NUM>, when the BS determines that the UE has performed random access without collision with another UE, the BS may transmit, to the UE, data (a contention resolution message or message <NUM>) including an ID of the UE that has transmitted the UL data in the third step <NUM>. When receiving the signal transmitted by the BS in the fourth step <NUM>, the UE determines that random access is successful. The UE may then transmit HARQ-ACK or NACK indicating whether the message <NUM> was successfully received to the BS in a UL control channel (or physical uplink control channel (PUCCH)).

When the data transmitted by the UE in the third step <NUM> collides with data from another UE and the BS fails to receive the data from the UE, the BS may not perform any more data transmission to the UE. Hence, when the UE fails to receive data transmitted in the fourth step <NUM> from the BS in a certain time period, the UE may determine that the random access procedure has failed and may restart from the first step <NUM>.

As described above, in the first step <NUM> of the random access procedure, the UE may transmit the random access preamble in a PRACH. There are <NUM> available preamble sequences in each cell, and depending on the transmission type, four long preamble formats and nine short preamble formats may be used. The UE may use a root sequence index and a cyclic shift value signaled in the system information to create the <NUM> preamble sequences, and randomly select and use one sequence as a preamble.

The network may notify the UE of which time-frequency resources may be used for the PRACH in an SIB or through higher layer signaling. The frequency resource indicates a starting RB point for transmission to the UE, and the number of RBs to be used may be determined based on the preamble format and SCS applied. The network may notify the UE of the time resource such as a subframe index and a start symbol including a preset PRACH configuration cycle and a PRACH transmission time (interchangeably used with a PRACH occasion or transmission time), the number of PRACH transmission occasions in the slot, etc., which are preset in Table <NUM> below, through a PRACH configuration index (<NUM> to <NUM>). Through the PRACH configuration index, random access configuration information included in the SIB, and an index of an SSB selected by the UE, the UE may identify time and frequency resources in which to transmit the random access preamble and transmit the selected sequence to the BS as a preamble.

<FIG> illustrates an example of UL-DL configurations considered in a <NUM> communication system. In the <NUM> communication system, UL-DL configurations of symbols/slots may be set up in three steps. First, UL-DL of a symbol/slot may be semi-statically configured in symbols through cell-specific configuration information <NUM> in system information. Specifically, the cell-specific UL-DL configuration information in the system information may include UL-DL pattern information and reference subcarrier information. Through the UL-DL pattern information, a pattern periodicity <NUM>, the number of consecutive DL slots <NUM> from a starting point of each pattern and the number of symbols <NUM> of the next slot, and the number of consecutive UL slots <NUM> from the end of the pattern and the number of symbols <NUM> of the next slot may be indicated. In this case, the UE may determine slots and symbols for which UL or DL is not indicated as flexible slots and symbols.

Second, through user-specific configuration information by dedicated higher layer signaling, slots <NUM> and <NUM> including the flexible slot or flexible symbol may be indicated with the numbers <NUM> and <NUM> of consecutive DL symbols from the starting symbol of each slot and the numbers <NUM> and <NUM> of consecutive UL symbols from the end of each slot or may be indicated as full-slot DL or full-slot UL.

Finally, to dynamically change the DL signal transmission section and the UL signal transmission section, symbols indicated as the flexible symbols (that is, symbols not indicated as DL or UL) in each slot may be indicated by slot format indicators (SFIs) <NUM> and <NUM> included in a DL control channel to indicate whether each symbol is a DL symbol, a UL symbol or a flexible symbol. The slot format indicator may select one index from a table in which UL-DL configurations of <NUM> symbols in one slot are set up in advance as in Table <NUM> below.

Although an additional coverage extension technology has been introduced for <NUM> mobile communication services as compared to traditional LTE communication services, coverage of the BS and the UE decreases as actual coverage of the <NUM> mobile communication services mostly uses a TDD system suitable for a service having a high proportion of DL traffic and has a higher center frequency to increase the frequency band, so coverage enhancement is a key requirement. Especially, because transmission power of the UE is generally lower than transmission power of the BS and a proportion of DL is higher than that of UL in the time domain to support a service having a higher DL traffic portion, coverage enhancement in the UL channel is a key demand. To enhance the coverage of the UL channel between the BS and the UE, there is a method of increasing time resources in the UL channel, reducing the center frequency, or increasing transmission power of the UE. Changing the frequency, however, is restricted to a frequency band determined for each network operator, and the maximum transmission power of the UE is determined within a rule to reduce interference.

Accordingly, to enhance coverage of the BS and the UE, UL and DL resources may be divided even in the frequency domain as in the FDD system instead of dividing portions in the time domain according to UL and DL traffic portions in the TDD system. A system that is able to flexibly divide UL and DL resources in the time domain and the frequency domain may be called an (time or frequency) divisional duplexing (DD) (XDD) system, flexible TDD system, a hybrid TDD system, a TDD-FDD system, a hybrid TDD-FDD system, etc., but will be called the XDD system in the disclosure.

<FIG> illustrates UL and DL configurations of an XDD system, in which UL and DL resources are divided flexibly in the time and frequency domain. From the perspective of the BS, an entire XDD system UL-DL configuration <NUM> may flexibly allocate a resource to each symbol or slot <NUM> depending on UL and DL traffic portions in an entire frequency band <NUM>. In this case, a guard band <NUM> may be allocated for a frequency band between a DL resource <NUM> and a UL resource <NUM>. The guard band may be allocated as a way to reduce interference in receiving a UL channel or signal due to out-of-band emission occurring when the BS transmits a DL channel or signal on the DL resource <NUM>. In this case, for example, UE <NUM><NUM> and UE <NUM><NUM> generally having more UL traffic than DL traffic may be allocated DL and UL resources at a ratio of <NUM>:<NUM> in the time domain according to a configuration from the BS. At the same time, UE <NUM><NUM> that is operating on cell edges and has insufficient UL coverage may be allocated only a UL resource in a particular time section according to a configuration from the BS. In addition, UE <NUM><NUM> that is operating on cell edges and has insufficient UL coverage but relatively has lots of DL and UL traffic may be allocated a lot of UL resources in the time domain for UL coverage and a lot of DL resources in the frequency domain. Like the above example, UEs operating relatively at a center of the cell and having lots of DL traffic may be allocated more DL resources in the time domain, and UEs operating relatively on cell edges and not having sufficient UL coverage may be allocated more UL resources in the time domain.

In the disclosure, UL coverage may be enhanced by optimizing relations between BWPs and UL-DL configurations to flexibly allocate UL and DL resources in the time and frequency domain. Main issues of the disclosure will now be described through specific embodiments.

Although the disclosure proposes a relation between a BWP and a UL-DL configuration and an associated method and apparatus for transmitting or receiving a channel and signal in the BS and the UE to enhance coverage, the disclosure will be applied to a method and apparatus for transmitting or receiving a channel and signal for a service (e.g., URLLC) that may be provided by a <NUM> system having different purposes than coverage enhancement. Furthermore, the disclosure provides a method and apparatus for transmitting or receiving a channel and signal in the BS and the UE in an XDD system, but the disclosure is not limited to the XDD system but may also be applied to a method and apparatus for transmitting or receiving a channel and signal in another division duplex system that may be provided in the <NUM> system.

A first embodiment of the disclosure is a method of configuring a relation between a BWP and a UL-DL configuration in the XDD system. Through the method of configuring a relation between a BWP and a UL-DL configuration as described in this embodiment, the UE may be allocated more required resources by BWP switching made depending on the occasion such as an occasion when the UL or DL time domain resource is not sufficient.

Specifically, as UL and DL resources may be divided and allocated not only in the time domain but also in the frequency domain in the XDD system as described above, UL-DL configurations may be made in the frequency domain and the time domain through a different UL-DL configuration for each BWP instead of performing the UL-DL configuration only in the time domain as in the traditional TDD system. The BS and the UE may change resources basically in the frequency domain through BWP switching and may change UL-DL configurations in the frequency domain and the time domain by changing resources in the time domain through a UL-DL configuration associated with the BWP.

Accordingly, methods of configuring a relation between a BWP and a UL-DL configuration in the XDD system is proposed.

The following methods may be considered as the method of configuring a relation between a BWP and a UL-DL configuration in the XDD system:.

The BS may perform UL-DL configurations in the time domain for each BWP for the UE. Therefore, when there is a change of BWP, the UL-DL configuration in the time domain may be changed as well. BWP-specific UL-DL configuration information configured for each BWP may include UL-DL pattern information and reference subcarrier information. The UL-DL pattern information may indicate a pattern periodicity <NUM> in the time domain, the number of consecutive DL slots <NUM> from a starting point of each pattern and the number of symbols <NUM> of the next slot, and the number of consecutive UL slots <NUM> from the end of the pattern and the number of symbols <NUM> of the next slot. In this case, slots and symbols for which UL or DL is not indicated may be determined as flexible slots and symbols.

In this method, UL-DL configurations for symbols/slots may be set up e.g., in four steps. First, UL-DL for symbols/slots corresponding to all BWPs (or a particular initial BWP or a default BWP) may be semi-statically configured in symbols through cell-specific configuration information in system information. Specifically, the cell-specific UL-DL configuration information in the system information may include UL-DL pattern information and reference subcarrier information. The UL-DL pattern information may indicate a pattern periodicity, the number of consecutive DL slots from a starting point of each pattern and the number of symbols of the next slot, and the number of consecutive UL slots from the end of the pattern and the number of symbols of the next slot. In this case, slots and symbols for which UL or DL is not indicated may be determined as flexible slots and symbols.

Second, through user-specific configuration information by dedicated higher layer signaling, slots including a flexible slot or flexible symbol corresponding to all BWPs (or a particular initial BWP or a default BWP) may be indicated with the number of consecutive DL symbols from the starting symbol of each slot and the number of consecutive UL symbols from the end of the slot or may be indicated as full-slot DL or full-slot UL.

Third, BWP-specific UL-DL may be configured by dedicated higher layer signaling. In a BWP for which there is a BWP-specific UL-DL configuration, the BWP-specific UL-DL configuration set up for the BWP is obeyed while the UL-DL configurations set up for all the BWPs (or a particular initial BWP or a default BWP) in the first step are ignored. The BWP-specific UL-DL configuration may include UL-DL pattern information and reference subcarrier information as in the cell-specific UL-DL configuration information. The UL-DL pattern information may indicate a pattern periodicity, the number of consecutive DL slots from a starting point of each pattern and the number of symbols of the next slot, and the number of consecutive UL slots from the end of the pattern and the number of symbols of the next slot. In this case, slots and symbols for which UL or DL is not indicated may be determined as flexible slots and symbols.

Finally, to dynamically change the DL signal transmission section and the UL signal transmission section, symbols indicated as the flexible symbols (that is, symbols not indicated as DL or UL) in each slot may be indicated by slot format indicators (SFIs) <NUM> and <NUM> included in a DL control channel to indicate whether each symbol is a DL symbol, a UL symbol or a flexible symbol. To indicate this, one index may be selected through the slot format indicator from a table in which UL-DL configurations for <NUM> symbols to indicate this.

UL-DL configuration of symbols/slots is not limited to the method but may be performed in other various methods.

<FIG> illustrates an example of UL-DL configurations for each BWP in the time domain in an XDD system. Referring to <FIG>, one UE may be configured with four BWPs <NUM>, <NUM>, <NUM> and <NUM> for UL-DL in the respective time domain. For example, pattern periodicity of BWP#<NUM><NUM> being <NUM> slots <NUM> (or <NUM> based on <NUM> of SCS), the number of consecutive DL slots from a starting point of the pattern being three <NUM>, the number of DL symbols in the next slot being seven <NUM>, the number of consecutive UL slots being one <NUM> from an end of the pattern, and the number of UL symbols in the next slot being four <NUM> may be configured. In this case, BWP#<NUM><NUM> is configured with more DL resources than UL resources in the time domain, so it may be activated for the UE when DL traffic is higher than UL traffic. Pattern periodicity of BWP#<NUM><NUM> being <NUM> slots <NUM> (or <NUM> based on <NUM> of SCS), the number of consecutive DL slots from a starting point of the pattern being zero, the number of DL symbols in the next slot being seven <NUM>, the number of consecutive UL slots being four <NUM> from an end of the pattern, and the number of UL symbols in the next slot being four <NUM> may be configured. In this case, BWP#<NUM><NUM> is configured with a narrow frequency band and more UL resources than DL resources in the time domain, so it may be activated for the UE for UL repetitive transmission when UL coverage is insufficient. Pattern periodicity of BWP#<NUM><NUM> being <NUM> slots <NUM> (or <NUM> based on <NUM> of SCS), the number of consecutive DL slots from a starting point of the pattern being three <NUM>, the number of DL symbols in the next slot being seven <NUM>, the number of consecutive UL slots being one <NUM> from an end of the pattern, and the number of UL symbols in the next slot being four <NUM> may be configured. In this case, BWP#<NUM><NUM> is configured with a wide frequency band and more DL resources than UL resources in the time domain, so it may be activated for the UE when high traffic is required for the service and DL traffic is higher than UL traffic. Pattern periodicity of BWP#<NUM><NUM> being <NUM> slots <NUM> (or <NUM> based on <NUM> of SCS), the number of consecutive DL slots from a starting point of the pattern being zero, the number of DL symbols in the next slot being seven <NUM>, the number of consecutive UL slots being four <NUM> from an end of the pattern, and the number of UL symbols in the next slot being four <NUM> may be configured. In this case, BWP#<NUM><NUM> is configured with a wide frequency band and more UL resources than DL resources in the time domain, so it may be activated for the UE to support a service having high DL traffic while performing UL repetitive transmission when UL coverage is short but the service requires high traffic. BWP#<NUM><NUM> and BWP#<NUM><NUM> have the same frequency band, but BWP#<NUM> may be configured with a DL resource and BWP#<NUM> may be configured with a UL resource in the same time domain according to the UL-DL configuration. In this case, even when the UE is configured with the resource <NUM> or <NUM> in all the frequency bands, the UE may determine which resource <NUM> or <NUM> has been actually configured in the frequency band according to other configurations (guard band configuration or indication or BWP configuration) (a method of identifying which resource of the frequency band is for DL or UL in the configured frequency band is proposed in a second embodiment).

The method may easily change the UL-DL configuration by BWP switching and associated change in UL-DL configuration without additional indication or signaling. In this case, from the perspective of the UE, UL-DL may be efficiently configured with little overhead because the UE is indicated about a UL-DL configuration for a currently activated BWP without need to be indicated about configurations of all resources.

The BS may perform UL-DL configuration in multiple time domains for the UE. Accordingly, UL-DL configuration may be performed in the time domain not for each BWP but in combination. UL-DL configuration in the time domain is not changed along with the BWP switching, but may be changed separately from the BWP.

In this method, UL-DL configurations for symbols/slots may be set up e.g., in three steps. First, UL-DL configuration of one or more symbols/slots may be semi-statically performed in symbols through cell-specific configuration information <NUM> in system information. Specifically, each cell-specific UL-DL configuration information in the system information may include UL-DL pattern information and reference subcarrier information. Through the UL-DL pattern information, a pattern periodicity <NUM>, the number of consecutive DL slots <NUM> from a starting point of each pattern and the number of symbols <NUM> of the next slot, and the number of consecutive UL slots <NUM> from the end of the pattern and the number of symbols <NUM> of the next slot may be indicated. In this case, slots and symbols for which UL or DL is not indicated may be determined as flexible slots and symbols. One or more cell-specific UL-DL configurations may be indicated, and the UE may be indicated about one of them.

Second, through user-specific configuration information by dedicated higher layer signaling, slots <NUM> and <NUM> including the flexible slot or flexible symbol in the indicated cell-specific UL-DL configuration may be indicated with the numbers <NUM> and <NUM> of consecutive DL symbols from the starting symbol of each slot and the numbers <NUM> and <NUM> of consecutive UL symbols from the end of each slot or may be indicated as full-slot DL or full-slot UL.

Finally, to dynamically change the DL signal transmission section and the UL signal transmission section, symbols indicated as the flexible symbols (that is, symbols not indicated as DL or UL) in each slot may be indicated by slot format indicators (SFIs) <NUM> and <NUM> included in a DL control channel to indicate whether each symbol is a DL symbol, a UL symbol or a flexible symbol. To indicate this, the slot format indicator may select one index from a table in which UL-DL configurations for <NUM> symbols in one slot are set up in advance as in Table <NUM> above.

UL-DL configuration of symbols/slots in the method is not limited to the method but may be performed in other various methods.

<FIG> illustrates an example of association between a BWP and a UL-DL configuration in the time domain in an XDD system. Referring to <FIG>, one UE is configured with three BWPs <NUM>, <NUM>, and <NUM> and indicated about UL-DL configurations <NUM> and <NUM> in two time domains. For example, pattern periodicity of UL-DL configuration#<NUM><NUM> in the first time domain being <NUM> slots <NUM> (or <NUM> based on <NUM> of SCS), the number of consecutive DL slots from a starting point of the pattern being three <NUM>, the number of DL symbols in the next slot being seven <NUM>, the number of consecutive UL slots being one <NUM> from an end of the pattern, and the number of UL symbols in the next slot being four <NUM> may be configured. Pattern periodicity of UL-DL configuration#<NUM><NUM> in the second time domain being <NUM> slots <NUM> (or <NUM> based on <NUM> of SCS), the number of consecutive DL slots from a starting point of the pattern being zero, the number of DL symbols in the next slot being seven <NUM>, the number of consecutive UL slots being four <NUM> from an end of the pattern, and the number of UL symbols in the next slot being four <NUM> may be configured. When the BWP#<NUM><NUM> is activated and the UE is indicated about UL-DL configuration#<NUM><NUM>, the UE may be configured with the configuration when DL traffic is higher than UL traffic because the UE is configured <NUM> to have more DL resources than UL resources in the time domain. Moreover, when UL-DL configuration#<NUM><NUM> is indicated, the UE may be configured with the configuration when the UE has more UL traffic than DL traffic because more UL resources are configured than DL resources <NUM>. In addition, when BWP#<NUM><NUM> is activated and the UE is indicated about UL_DL configuration#<NUM><NUM>, the UE may be configured with the configuration when having low traffic <NUM> because there are small frequency resources <NUM>. When BWP#<NUM><NUM> is activated and the UE is indicated about UL-DL configuration#<NUM><NUM>, UEs located on cell edges and having short UL coverage may be configured with the configuration because there are small frequency resources and more UL resources are allocated than the DL resources in the time domain. When BWP#<NUM><NUM> is activated and UL-DL configuration#<NUM><NUM> is indicated, the UE may be indicated about UL-DL configuration#<NUM><NUM> when having high traffic because it uses the entire frequency resources <NUM>. In this case, even though the UE is configured with the resources <NUM> in the entire frequency band, the UE may determine which resource <NUM> or <NUM> has been actually configured in the frequency band according to other configurations (guard band configuration or indication or BWP configuration) (a method of identifying which resource of the frequency band is for DL or UL in the configured frequency band is proposed in the second embodiment).

The method may support a lot more cases and may be applied to various scenarios by separately configuring the BWP and the UL-DL configuration.

The second embodiment of the disclosure describes a method of identifying which resource in the frequency domain is for DL or UL in the first embodiment. The UE may need to determine which resource is actually allocated in the frequency domain when the UE is configured with a UL-DL configuration only in the time domain as in the previous embodiment. In the XDD system in particular, as described above, as a way to reduce interference in receiving a UL channel or signal due to out-of-band emission occurring when the BS transmits a DL channel or signal in a DL resource, a guard band is configured, but when the configuration is violated because of wrong reception or wrong determination of the UE, both DL and UL may be subject to severe interference. To prevent this, a method of identifying a resource configuration in the frequency domain even when the UE is configured with a UL-DL configuration only in the time domain will be described.

Specifically, the UE may determine that there is only DL or UL resource at one point when there is no guard band, and determine that there are both UL and DL resources at one point in the frequency domain when the guard band is configured. Furthermore, as described above, it is very difficult for the BS to implement resource allocation that avoids consecutive DLs or ULs at the same point in time, and as mentioned above, interference due to the out-of-band emission occurs between UL and DL, and accordingly may occur at multiple points. Hence, the UE and the BS may indirectly identify between DL resource and UL resource by configuring the guard band. However, when a frequency band in a BWP includes the guard band, a higher frequency section and a lower frequency section may be separated based on the guard band but the UE may not determine which one is for UL or DL based on only the guard band.

Hence, the following methods may be considered as a method of identifying resource configurations in the frequency domain even when the UE is configured with the UL-DL configuration only in the time domain in the XDD system.

The UE may determine that a section including a frequency band for which an initial BWP (or default BWP or the lowest indexed BWP) is configured has been configured as DL resources. Specifically, as an SSB block always needs to be transmitted from the BS for UEs that make initial access thereto in the initial BWP, the guard band is prevented from being included and many resources may be considered as DL resources. Hence, a section having higher frequencies is separated from a section having lower frequencies based on the configured guard band, and the section including the initial BWP in the frequency band may be determined as being configured for DL and the section not including the initial BWP may be determined as being configured for U L.

<FIG> is a flowchart for describing operations of a method by which the UE is able to identify resource configurations in a frequency band, according to the second embodiment.

The UE may receive guard band location and size configuration information and a UL-DL configuration in the time domain in operation <NUM>. The UE may receive information for dynamically enabling or disabling or activating or releasing) the guard band and scheduling channel information through higher layer signaling or DCI, in operation <NUM>. Operations <NUM> and <NUM> are described sequentially for convenience of explanation, but may be performed at the same time or in a different order. The UE may compare a slot/symbol format based on the UL-DL configuration in the time domain and a format of the configured or scheduled channel, in operation <NUM>. When the slot/symbol format based on the UL-DL configuration in the time domain is different from the format of the configured or scheduled channel in operation <NUM>, the UE does not perform transmission when the format of the configured or scheduled channel or signal is UL and does not perform reception when the format is DL in operation <NUM>. When the slot/symbol format based on the UL-DL configuration in the time domain is the same as the format of the configured or scheduled channel in operation <NUM>, the UE determines whether the guard band is dynamically enabled or disabled (or activated or released) in operation <NUM>. When the UE determines that the guard band is dynamically disabled (or released) in operation <NUM>, the UE performs transmission when the format of the configured or scheduled channel or signal is UL and performs reception when the format is DL in <NUM>. When the UE determines that the guard band is dynamically enabled (or activated) in operation <NUM>, the UE compares an initial BWP configured based on the frequency band of the guard band and a location of the channel configured or scheduled by higher layer signaling or DCI in operation <NUM>. When the initial BWP configured based on the frequency band of the guard band and the location of the channel or signal configured or scheduled through higher layer signaling or DCI are the same, the UE does not transmit a configured or scheduled UL channel or signal but receives a configured or scheduled DL channel or signal, in operation <NUM>. When the initial BWP configured based on the frequency band of the guard band is different from the location of the channel or signal configured or scheduled through higher layer signaling or DCI, the UE transmits the configured or scheduled UL channel or signal and does not receive the configured or scheduled DL channel or signal, in operation <NUM>.

This method is not limited to using the frequency band of the initial BWP, and may be applied to a frequency band of a default BWP or the lowest indexed BWP instead of the frequency band of the initial BWP.

The UE may determine that a section including a frequency band in which an SSB including SIB information is transmitted is configured as a DL resource. Specifically, as an SSB block including the SIB information always needs to be transmitted from the BS for UEs that make initial access thereto in a frequency band in which the SSB including the SIB information is transmitted, the guard band is prevented from being included and many resources may be considered as DL resources. Hence, a section having higher frequencies is separated from a section having lower frequencies based on the configured guard band, and the section included in the frequency band in which the SSB including the SIB information is transmitted may be determined as being configured for DL and the section not including the frequency band where the SSB including the SIB information is transmitted may be determined as being configured for U L.

<FIG> is a flowchart for describing operations of another method by which the UE is able to identify resource configurations in a frequency band, according to the second embodiment.

The UE may receive guard band location and size configuration information and a UL-DL configuration in the time domain in operation <NUM>. The UE may receive information for dynamically enabling or disabling or activating or releasing) the guard band and scheduling channel information through higher layer signaling or DCI, in operation <NUM>. Operations <NUM> and <NUM> are described sequentially for convenience of explanation, but may be performed at the same time or in a different order. The UE compares a slot/symbol format based on the UL-DL configuration in the time domain and a format of the configured or scheduled channel, in operation <NUM>. When the slot/symbol format based on the UL-DL configuration in the time domain is different from the format of the configured or scheduled channel in operation <NUM>, the UE does not perform transmission when the format of the configured or scheduled channel or signal is UL and does not perform reception when the format is DL in operation <NUM>. When the slot/symbol format based on the UL-DL configuration in the time domain is the same as the format of the configured or scheduled channel in operation <NUM>, the UE determines whether the guard band is dynamically enabled or disabled (or activated or released) in operation <NUM>. When the UE determines that the guard band is dynamically disabled (or released) in operation <NUM>, the UE performs transmission when the format of the configured or scheduled channel or signal is UL and performs reception when the format is DL in <NUM>. When the UE determines that the guard band is dynamically enabled (or activated) in operation <NUM>, the UE compares the frequency band, in which the SSB including the SIB information is transmitted, configured based on the frequency band of the guard band and a location of the channel configured or scheduled by higher layer signaling or DCI in operation <NUM>. When the frequency band, in which the SSB including the SIB information is transmitted, based on the frequency band of the guard band and the location of the channel or signal configured or scheduled through higher layer signaling or DCI are the same, the UE does not transmit the configured or scheduled UL channel or signal but receives the configured or scheduled DL channel or signal, in operation <NUM>. When the frequency band, in which the SSB including the SIB information is transmitted, based on the frequency band of the guard band is different from the location of the channel or signal configured or scheduled through higher layer signaling or DCI, the UE transmits the configured or scheduled UL channel or signal and does not receive the configured or scheduled DL channel or signal, in operation <NUM>.

The UE may determine that a section including a frequency band in which a PRACH may be transmitted is configured as a UL resource. Specifically, a frequency band in which a PRACH may be transmitted is prevented from being included in the guard band and may always be considered as a UL resource because the BS needs to be always available for PRACH reception for UEs that make initial access thereto, the time of which may not be predicted. Hence, a section having higher frequencies may be separated from a section having lower frequencies based on the configured guard band, and the section included in the frequency band in which the PRACH may be transmitted may be determined as being configured for UL and the section not including the frequency band where the PRACH may be transmitted may be determined as being configured for DL.

The UE may receive guard band location and size configuration information and a UL-DL configuration in the time domain in operation <NUM>. The UE may receive information for dynamically enabling or disabling or activating or releasing) the guard band and scheduling channel information through higher layer signaling or DCI, in operation <NUM>. Operations <NUM> and <NUM> are described sequentially for convenience of explanation, but may be performed at the same time or in a different order. The UE compares a slot/symbol format based on the UL-DL configuration in the time domain and a format of the configured or scheduled channel, in operation <NUM>. When the slot/symbol format based on the UL-DL configuration in the time domain is different from the format of the configured or scheduled channel in operation <NUM>, the UE does not perform transmission when the format of the configured or scheduled channel or signal is UL and does not perform reception when the format is DL in operation <NUM>. When the slot/symbol format based on the UL-DL configuration in the time domain is the same as the format of the configured or scheduled channel in operation <NUM>, the UE may determine whether the guard band is dynamically enabled or disabled (or activated or released) in operation <NUM>. When the UE determines that the guard band is dynamically disabled (or released) in operation <NUM>, the UE performs transmission when the format of the configured or scheduled channel or signal is UL and performs reception when the format is DL in <NUM>. When the UE determines that the guard band is dynamically enabled (or activated) in operation <NUM>, the UE compares the frequency band in which the PRACH is transmitted, configured based on the frequency band of the guard band and a location of the channel configured or scheduled by higher layer signaling or DCI in operation <NUM>. When the frequency band, in which the PRACH is transmitted, based on the frequency band of the guard band is the same as the location of the channel or signal configured or scheduled through higher layer signaling or DCI, the UE transmits the configured or scheduled UL channel or signal and does not receive the configured or scheduled DL channel or signal, in operation <NUM>. When the frequency band, in which the PRACH is transmitted, based on the frequency band of the guard band is different from the location of the channel or signal configured or scheduled through higher layer signaling or DCI, the UE does not transmit the configured or scheduled UL channel or signal but receives the configured or scheduled DL channel or signal, in operation <NUM>.

The UE may be indicated about whether a higher (or lower or higher and lower) frequency band based on the guard band is for UL or DL, from the BS through higher layer signaling or L1 signaling. The UE may be indicated about whether the frequency band is for UL or DL from the BS with small overhead. Specifically, when a higher (or lower) section of the frequency band based on the guard band is indicated as UL, the UE transmits a configured or scheduled UL channel or signal and does not receive a configured or scheduled DL channel or signal. On the contrary, when a higher (or lower) section of the frequency band based on the guard band is indicated as DL, the UE does not transmit the configured or scheduled UL channel or signal but receives the configured or scheduled DL channel or signal.

The aforementioned methods <NUM>, <NUM>, <NUM>, and <NUM> may be operated in combination.

<FIG> is a block diagram of a UE, according to an embodiment of the disclosure.

Referring to <FIG>, a UE <NUM> may include a transceiver <NUM>, a controller <NUM>, and a storage <NUM>. The transceiver <NUM>, the controller <NUM>, and the storage <NUM> of the UE <NUM> may operate according to a method of efficiently transmitting or receiving a channel and signal in the <NUM> communication system as described above in connection with the previous embodiments. The elements of the UE <NUM> is not, however, limited thereto. For example, the UE <NUM> may include more or fewer elements than described above. In addition, in a special occasion, the transceiver <NUM>, the controller <NUM>, and the storage <NUM> may be implemented in the form of a single chip.

The transceiver <NUM> may include a transmitter and a receiver in another embodiment. The transceiver <NUM> may transmit or receive signals to or from a BS. The signals may include control information and data. For this, the transceiver <NUM> may include an RF transmitter for up-converting the frequency of a signal to be transmitted and amplifying the signal and an RF receiver for low-noise amplifying a received signal and down-converting the frequency of the received signal. In addition, the transceiver <NUM> may receive a signal on a wireless channel and output the signal to the controller <NUM>, or transmit a signal output from the controller <NUM> on a wireless channel.

The controller <NUM> may control a series of processes for the UE <NUM> to be operated according to the embodiments of the disclosure. For example, the controller <NUM> may perform at least one of a BWP-specific UL-DL configuration method, a method by which the UE is able to identify resource configurations in the frequency domain even when configured with UL-DL configurations only in the time domain, and a UL channel or signal transmission method and a DL channel or signal reception method in the UE. The storage <NUM> may store control information or data such as UL-DL configuration information, guard band configuration information, etc., included in a signal obtained by the UE <NUM>, and have sectors for storing data required for control of the controller <NUM> and data that occurs during the control in the controller <NUM>.

<FIG> is a block diagram of a BS, according to an embodiment.

Referring to <FIG>, a BS <NUM> may include a transceiver <NUM>, a controller <NUM>, and a storage <NUM>. The transceiver <NUM>, the controller <NUM>, and the storage <NUM> of the BS <NUM> may operate according to a method of efficiently transmitting or receiving a channel and signal in the <NUM> communication system as described above in connection with the previous embodiments. The elements of the BS <NUM> is not, however, limited thereto. In another embodiment, the BS <NUM> may include more or fewer elements than described above. In addition, in a special occasion, the transceiver <NUM>, the controller <NUM>, and the storage <NUM> may be implemented in the form of a single chip. The transceiver <NUM> may include a transmitter and a receiver in another embodiment. The transceiver <NUM> may transmit or receive signals to or from a UE. The signals may include control information and data. For this, the transceiver <NUM> may include an RF transmitter for up-converting the frequency of a signal to be transmitted and amplifying the signal and an RF receiver for low-noise amplifying a received signal and down-converting the frequency of the received signal. In addition, the transceiver <NUM> may receive a signal on a wireless channel and output the signal to the controller <NUM>, or transmit a signal output from the controller <NUM> on a wireless channel.

The controller <NUM> may control a series of processes for the BS <NUM> to be operated according to the embodiments of the disclosure. For example, the controller <NUM> may perform at least one of a BWP-specific UL-DL configuration method, a method of identifying resource configurations in the frequency domain even when configured with UL-DL configurations only in the time domain, and a UL channel or signal reception method and a DL channel or signal transmission method in the BS.

The storage <NUM> may store control information or data such as UL-DL configuration information, guard band configuration information, etc., determined by the BS <NUM>, or control information or data received from the UE, and have sectors for storing data required for control of the controller <NUM> and data that occurs during the control in the controller <NUM>.

A method of configuring a BWP in a UE in a wireless communication system according to an embodiment may include obtaining system information including UL-DL configuration information; identifying a UL-DL pattern and reference subcarrier information based on the UL-DL configuration information; and determining a flexible symbol corresponding to a symbol not configured as UL or DL, based on a result of the identifying.

A method performed by a UE in a wireless communication system according to an embodiment may include receiving resource configuration information in a time domain for UL or DL in a plurality of BWPs from a BS; receiving information about an activated BWP from the BS; determining a UL resource or a DL resource in the time domain corresponding to the activated BWP based on the resource configuration information and the information about the activated BWP; and communicating with the BS based on the UL resource or the DL resource of the time domain corresponding to the activated BWP.

According to an embodiment, the activated BWP may include at least one BWP among the plurality of BWPs determined based on an amount of traffic or UL coverage.

According to an embodiment, the method may further include receiving information about a guard band for distinguishing between a UL resource and a DL resource in a frequency domain of the activated BWP from the BS.

According to an embodiment, the information about the guard band may indicate that the UL resource and the DL resource are present in a same time section in the frequency domain.

According to an embodiment, the communicating with the BS may include performing transmission of UL data or reception of DL data according to the received information about the guard band.

According to an embodiment, the performing of transmission of the UL data or reception of the DL data may include determining at least one of frequency bands, in which an SSB is transmitted, as a DL resource, when the guard band is present in the frequency domain.

According to an embodiment, the performing of the transmission of the UL data or the reception of the DL data may include determining at least one of frequency bands, in which a PRACH is transmitted, as a UL resource, when the guard band is present in the frequency domain.

According to an embodiment, the performing of the transmission of the UL data or the reception of the DL data may include determining at least one of frequency bands corresponding to an initial BWP as a DL resource, when the guard band is present in the frequency domain.

A method performed by a BS in a wireless communication system according to an embodiment may include transmitting resource configuration information in a time domain for UL or DL in a plurality of BWPs to a UE; transmitting information about an activated BWP to the UE; and communicating with the UE based on a UL resource or a DL resource in the time domain corresponding to the activated BWP determined according to the resource configuration information and the information about the activated BWP.

According to an embodiment, the method may further include transmitting information about a guard band for distinguishing between a UL resource and a DL resource in a frequency domain of the activated BWP to the UE.

According to an embodiment, the communicating with the UE may include performing reception of UL data or transmission of DL data according to the received information about the guard band.

According to an embodiment, at least one of frequency bands, in which an SSB is transmitted, may be determined as a DL resource, when the guard band is present in the frequency domain.

Claim 1:
A method performed by a user equipment, UE, (<NUM>) in a wireless communication system, the method comprising:
receiving (<NUM>), from a base station, BS, resource configuration information for uplink, UL, or downlink, DL, transmission in a plurality of bandwidth parts, BWPs, the resource configuration information indicating UL and DL resources configured per BWP in a time domain;
receiving (<NUM>), from the BS, information associated with an activated BWP;
determining frequency domain resource information corresponding to the activated BWP;
determining time domain resource information, based on the resource configuration information and the activated BWP, the time domain resource information including at least one UL resource and at least one DL resource configured for the activated BWP; and
communicating (<NUM>; <NUM>; <NUM>) with the BS based on the time domain resource information and the frequency domain resource information.