KR20220051073A - Method and apparatus for scheduling a data channel in a wireless mobile communication system - Google Patents

Abstract

The present disclosure provides a method for allowing one PCell to transmit a PDCCH including scheduling control information for a data channel, transmitted through another SCell, or to receive a PDCCH including scheduling control information for a data channel, transmitted through the one SCell, through a PSCell or the another SCell, when a PCell is configured in a first frequency band and an SCell is configured in a second frequency band, in a method for scheduling a data channel in a wireless mobile communication system.

Description

Method and apparatus for scheduling a data channel in a wireless mobile communication system

The present invention provides a method of allocating a data channel transmission resource during frequency merging in a next-generation/5G radio access network (hereinafter, referred to as NR [New Radio] in the present invention).

In one aspect, the present embodiments provide a method for scheduling a data channel in a wireless mobile communication system. When a PCell is configured in a first frequency band and an SCell is configured in a second frequency band, one SCell uses another SCell. Transmitting a PDCCH including scheduling control information for a data channel transmitted through the PSCell or receiving a PDCCH including scheduling control information for a data channel transmitted through the one SCell through the PSCell or the other SCell method can be provided.

1 is a diagram schematically illustrating a structure of an NR wireless communication system to which this embodiment can be applied.
2 is a diagram for explaining a frame structure in an NR system to which this embodiment can be applied.
3 is a diagram for explaining a resource grid supported by a radio access technology to which this embodiment can be applied.
4 is a diagram for explaining a bandwidth part supported by a radio access technology to which the present embodiment can be applied.
5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which the present embodiment can be applied.
6 is a diagram for explaining a random access procedure in a radio access technology to which this embodiment can be applied.
7 is a diagram for explaining CORESET.
8 is a diagram illustrating an example of symbol level alignment among different SCSs to which this embodiment can be applied.
9 is a diagram illustrating a conceptual example of a bandwidth part to which the present embodiment can be applied.
10 is a diagram showing the configuration of a base station according to another embodiment.
11 is a diagram showing the configuration of a user terminal according to another embodiment.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present embodiments, if it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present technical idea, the detailed description may be omitted. When "includes", "having", "consisting of", etc. mentioned in this specification are used, other parts may be added unless "only" is used. When a component is expressed in the singular, it may include a case in which the plural is included unless otherwise explicitly stated.

In addition, in describing the components of the present disclosure, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms.

In the description of the positional relationship of the components, when it is described that two or more components are "connected", "coupled" or "connected", two or more components are directly "connected", "coupled" or "connected" ", but it will be understood that two or more components and other components may be further "interposed" and "connected," "coupled," or "connected." Here, other components may be included in one or more of two or more components that are “connected”, “coupled” or “connected” to each other.

In the description of the temporal flow relationship related to the components, the operation method or the production method, for example, the temporal precedence relationship such as "after", "after", "after", "before", etc. Alternatively, when a flow precedence relationship is described, it may include a case where it is not continuous unless "immediately" or "directly" is used.

On the other hand, when numerical values or corresponding information (eg, level, etc.) for a component are mentioned, even if there is no separate explicit description, the numerical value or the corresponding information is based on various factors (eg, process factors, internal or external shock, Noise, etc.) may be interpreted as including an error range that may occur.

A wireless communication system in the present specification refers to a system for providing various communication services such as voice and data packets using radio resources, and may include a terminal, a base station, or a core network.

The present embodiments disclosed below may be applied to a wireless communication system using various wireless access technologies. For example, the present embodiments are CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access) Alternatively, it may be applied to various various radio access technologies such as non-orthogonal multiple access (NOMA). In addition, the wireless access technology may mean not only a specific access technology, but also a communication technology for each generation established by various communication consultation organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA may be implemented with a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with a radio technology such as global system for mobile communications (GSM)/general packet radio service (GPRS)/enhanced datarates for GSM evolution (EDGE). OFDMA may be implemented with a radio technology such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and evolved UTRA (E-UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, and provides backward compatibility with a system based on IEEE 802.16e. UTRA is part of the universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) that uses evolved-UMTSterrestrial radio access (E-UTRA), and employs OFDMA in the downlink and SC- FDMA is employed. As such, the present embodiments may be applied to currently disclosed or commercialized radio access technologies, or may be applied to radio access technologies currently under development or to be developed in the future.

On the other hand, the terminal in the present specification is a comprehensive concept meaning a device including a wireless communication module that performs communication with a base station in a wireless communication system, WCDMA, LTE, NR, HSPA and IMT-2020 (5G or New Radio), etc. It should be interpreted as a concept including all of UE (User Equipment), MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), wireless device, etc. in GSM. In addition, the terminal may be a user's portable device such as a smart phone depending on the type of use, and in a V2X communication system may mean a vehicle, a device including a wireless communication module in the vehicle, and the like. In addition, in the case of a machine type communication (Machine Type Communication) system, it may mean an MTC terminal, an M2M terminal, a URLLC terminal, etc. equipped with a communication module to perform machine type communication.

A base station or cell of the present specification refers to an end that communicates with a terminal in terms of a network, a Node-B (Node-B), an evolved Node-B (eNB), gNode-B (gNB), a Low Power Node (LPN), Sector, site, various types of antennas, base transceiver system (BTS), access point, point (eg, transmission point, reception point, transmission/reception point), relay node ), mega cell, macro cell, micro cell, pico cell, femto cell, RRH (Remote Radio Head), RU (Radio Unit), small cell (small cell), such as a variety of coverage areas. In addition, the cell may mean including a BWP (Bandwidth Part) in the frequency domain. For example, the serving cell may mean the Activation BWP of the UE.

In the various cells listed above, since there is a base station controlling one or more cells, the base station can be interpreted in two meanings. 1) in relation to the radio area, it may be the device itself providing a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, or a small cell, or 2) may indicate the radio area itself. In 1), the devices providing a predetermined radio area are controlled by the same entity, or all devices interacting to form a radio area cooperatively are directed to the base station. A point, a transmission/reception point, a transmission point, a reception point, etc. become an embodiment of a base station according to a configuration method of a wireless area. In 2), the radio area itself in which signals are received or transmitted from the point of view of the user terminal or the neighboring base station may be indicated to the base station.

In the present specification, a cell is a component carrier having a coverage of a signal transmitted from a transmission/reception point or a coverage of a signal transmitted from a transmission/reception point (transmission point or transmission/reception point), and the transmission/reception point itself. can

The uplink (Uplink, UL, or uplink) refers to a method of transmitting and receiving data by the terminal to the base station, and the downlink (Downlink, DL, or downlink) refers to a method of transmitting and receiving data to the terminal by the base station do. Downlink may mean a communication or communication path from a multi-transmission/reception point to a terminal, and uplink may mean a communication or communication path from a terminal to a multi-transmission/reception point. In this case, in the downlink, the transmitter may be a part of multiple transmission/reception points, and the receiver may be a part of the terminal. In addition, in the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of the multi-transmission/reception point.

The uplink and the downlink transmit and receive control information through a control channel such as a Physical Downlink Control CHannel (PDCCH) and a Physical Uplink Control CHannel (PUCCH), and a Physical Downlink Shared CHannel (PDSCH), a Physical Uplink Shared CHannel (PUSCH), etc. Data is transmitted and received by configuring the same data channel. Hereinafter, a situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH may be expressed in the form of 'transmitting and receiving PUCCH, PUSCH, PDCCH and PDSCH'. do.

For clarity of explanation, the present technical idea will be mainly described below for the 3GPP LTE/LTE-A/NR (New RAT) communication system, but the present technical characteristics are not limited to the corresponding communication system.

In 3GPP, after research on 4G (4th-Generation) communication technology, 5G (5th-Generation) communication technology is developed to meet the requirements of ITU-R's next-generation wireless access technology. Specifically, 3GPP develops LTE-A pro, which improves LTE-Advanced technology to meet the requirements of ITU-R as a 5G communication technology, and a new NR communication technology separate from 4G communication technology. LTE-A pro and NR both refer to 5G communication technology. Hereinafter, 5G communication technology will be described focusing on NR unless a specific communication technology is specified.

In the NR operation scenario, various operation scenarios were defined by adding consideration of satellites, automobiles, and new verticals to the existing 4G LTE scenarios. It is deployed in a range and supports the mMTC (Massive Machine Communication) scenario that requires a low data rate and asynchronous connection, and the URLLC (Ultra Reliability and Low Latency) scenario that requires high responsiveness and reliability and supports high-speed mobility. .

To satisfy this scenario, NR discloses a wireless communication system to which a new waveform and frame structure technology, low latency technology, mmWave support technology, and forward compatible technology are applied. In particular, in the NR system, various technological changes are presented in terms of flexibility in order to provide forward compatibility. The main technical features of NR will be described with reference to the drawings below.

<Normal NR system>

1 is a diagram schematically illustrating a structure of an NR system to which this embodiment can be applied.

1, the NR system is divided into a 5G Core Network (5GC) and an NR-RAN part, and the NG-RAN controls the user plane (SDAP/PDCP/RLC/MAC/PHY) and UE (User Equipment) It consists of gNBs and ng-eNBs that provide planar (RRC) protocol termination. The gNB interconnects or gNBs and ng-eNBs are interconnected via an Xn interface. gNB and ng-eNB are each connected to 5GC through the NG interface. 5GC may be configured to include an Access and Mobility Management Function (AMF) in charge of a control plane such as terminal access and mobility control functions, and a User Plane Function (UPF) in charge of a control function for user data. NR includes support for both the frequency band below 6 GHz (FR1, Frequency Range 1) and the frequency band above 6 GHz (FR2, Frequency Range 2).

gNB means a base station that provides NR user plane and control plane protocol termination to a terminal, and ng-eNB means a base station that provides E-UTRA user plane and control plane protocol termination to a terminal. The base station described in this specification should be understood as encompassing gNB and ng-eNB, and may be used as a meaning to distinguish gNB or ng-eNB as needed.

<NR Waveform, Pneumologic and Frame Structure>

In NR, a CP-OFDM waveform using a cyclic prefix is used for downlink transmission, and CP-OFDM or DFT-s-OFDM is used for uplink transmission. OFDM technology is easy to combine with MIMO (Multiple Input Multiple Output), and has advantages of using a low-complexity receiver with high frequency efficiency.

Meanwhile, in NR, since the requirements for data rate, delay rate, coverage, etc. are different for each of the three scenarios described above, it is necessary to efficiently satisfy the requirements for each scenario through the frequency band constituting an arbitrary NR system. . To this end, a technique for efficiently multiplexing a plurality of different numerology-based radio resources has been proposed.

Specifically, the NR transmission numerology is determined based on sub-carrier spacing and cyclic prefix (CP), and the μ value is used as an exponential value of 2 based on 15 kHz as shown in Table 1 below. is changed to

μ subcarrier spacing Cyclic prefix Supported for data Supported for synch 0 15 Normal Yes Yes One 30 Normal Yes Yes 2 60 Normal, Extended Yes No 3 120 Normal Yes Yes 4 240 Normal No Yes

As shown in Table 1 above, the NR numerology can be divided into five types according to the subcarrier spacing. This is different from the fact that the subcarrier interval of LTE, one of the 4G communication technologies, is fixed at 15 kHz. Specifically, in NR, subcarrier intervals used for data transmission are 15, 30, 60, and 120 kHz, and subcarrier intervals used for synchronization signal transmission are 15, 30, 120, 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier interval. On the other hand, as for the frame structure in NR, a frame having a length of 10 ms is defined, which is composed of 10 subframes having the same length of 1 ms. One frame can be divided into half frames of 5 ms, and each half frame includes 5 subframes. In the case of a 15 kHz subcarrier interval, one subframe consists of one slot, and each slot consists of 14 OFDM symbols.

2 is a diagram for explaining a frame structure in an NR system to which this embodiment can be applied.

Referring to FIG. 2 , a slot is fixedly composed of 14 OFDM symbols in the case of a normal CP, but the length of the slot in the time domain may vary according to the subcarrier interval. For example, in the case of a numerology having a 15 kHz subcarrier interval, the slot is 1 ms long and is composed of the same length as the subframe. Contrary to this, in the case of numerology having a 30 kHz subcarrier interval, a slot consists of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, the subframe and the frame are defined to have a fixed time length, and the slot is defined by the number of symbols, so that the time length may vary according to the subcarrier interval.

Meanwhile, NR defines a basic unit of scheduling as a slot, and also introduces a mini-slot (or a sub-slot or a non-slot based schedule) in order to reduce transmission delay in a radio section. When a wide subcarrier interval is used, the length of one slot is shortened in inverse proportion, so that transmission delay in a radio section can be reduced. The mini-slot (or sub-slot) is for efficient support of the URLLC scenario and can be scheduled in units of 2, 4, or 7 symbols.

Also, unlike LTE, NR defines uplink and downlink resource allocation at a symbol level within one slot. In order to reduce the HARQ delay, a slot structure capable of transmitting HARQ ACK/NACK directly within a transmission slot has been defined, and this slot structure will be described as a self-contained structure.

NR is designed to support a total of 256 slot formats, of which 62 slot formats are used in 3GPP Rel-15. In addition, a common frame structure constituting an FDD or TDD frame is supported through a combination of various slots. For example, a slot structure in which all symbols of a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink symbols and uplink symbols are combined are supported. In addition, NR supports that data transmission is scheduled to be distributed in one or more slots. Accordingly, the base station may inform the terminal whether the slot is a downlink slot, an uplink slot, or a flexible slot using a slot format indicator (SFI). The base station may indicate the slot format by indicating the index of the table configured through UE-specific RRC signaling using SFI, and may indicate dynamically through DCI (Downlink Control Information) or statically or through RRC. It can also be ordered quasi-statically.

<NR Physical Resources>

In relation to a physical resource in NR, an antenna port, a resource grid, a resource element, a resource block, a bandwidth part, etc. are considered do.

An antenna port is defined such that a channel on which a symbol on an antenna port is carried can be inferred from a channel on which another symbol on the same antenna port is carried. When the large-scale property of a channel on which a symbol on one antenna port is carried can be inferred from a channel on which a symbol on another antenna port is carried, the two antenna ports are QC/QCL (quasi co-located or It can be said that there is a quasi co-location) relationship. Here, the wide range characteristic includes one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

3 is a diagram for explaining a resource grid supported by a radio access technology to which this embodiment can be applied.

Referring to FIG. 3 , in the resource grid, since NR supports a plurality of numerologies on the same carrier, a resource grid may exist according to each numerology. In addition, the resource grid may exist according to an antenna port, a subcarrier interval, and a transmission direction.

A resource block consists of 12 subcarriers, and is defined only in the frequency domain. In addition, a resource element is composed of one OFDM symbol and one subcarrier. Accordingly, as in FIG. 3 , the size of one resource block may vary according to the subcarrier interval. In addition, NR defines "Point A" serving as a common reference point for a resource block grid, a common resource block, a virtual resource block, and the like.

4 is a diagram for explaining a bandwidth part supported by a radio access technology to which the present embodiment can be applied.

In NR, unlike LTE in which the carrier bandwidth is fixed at 20Mhz, the maximum carrier bandwidth is set from 50Mhz to 400Mhz for each subcarrier interval. Therefore, it is not assumed that all terminals use all of these carrier bandwidths. Accordingly, in NR, as shown in FIG. 4, a bandwidth part (BWP) may be designated within the carrier bandwidth and used by the terminal. In addition, the bandwidth part is associated with one numerology and is composed of a subset of continuous common resource blocks, and may be dynamically activated according to time. Up to four bandwidth parts are configured in the terminal, respectively, in uplink and downlink, and data is transmitted/received using the activated bandwidth part at a given time.

In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, to prevent unnecessary frequency re-tunning between downlink and uplink operations For this purpose, the downlink and uplink bandwidth parts are set in pairs to share a center frequency.

<NR Initial Connection>

In NR, the terminal accesses the base station and performs a cell search and random access procedure in order to perform communication.

Cell search is a procedure in which the terminal synchronizes with the cell of the corresponding base station using a synchronization signal block (SSB) transmitted by the base station, obtains a physical layer cell ID, and obtains system information.

5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 5, the SSB consists of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) occupying 1 symbol and 127 subcarriers, respectively, and a PBCH spanning 3 OFDM symbols and 240 subcarriers.

The UE receives the SSB by monitoring the SSB in the time and frequency domains.

SSB can be transmitted up to 64 times in 5ms. A plurality of SSBs are transmitted using different transmission beams within 5 ms, and the UE performs detection on the assumption that SSBs are transmitted every 20 ms when viewed based on one specific beam used for transmission. The number of beams that can be used for SSB transmission within 5 ms time may increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted in 3 GHz or less, and SSB can be transmitted using up to 8 different beams in a frequency band of 3 to 6 GHz and up to 64 different beams in a frequency band of 6 GHz or more.

Two SSBs are included in one slot, and the start symbol and the number of repetitions within the slot are determined according to the subcarrier interval as follows.

On the other hand, the SSB is not transmitted at the center frequency of the carrier bandwidth, unlike the SS of the conventional LTE. That is, the SSB may be transmitted in a place other than the center of the system band, and a plurality of SSBs may be transmitted in the frequency domain when wideband operation is supported. Accordingly, the UE monitors the SSB using a synchronization raster that is a candidate frequency location for monitoring the SSB. The carrier raster and synchronization raster, which are the center frequency location information of the channel for initial access, are newly defined in NR. Compared to the carrier raster, the synchronization raster has a wider frequency interval than that of the carrier raster. can

The UE may acquire the MIB through the PBCH of the SSB. MIB (Master Information Block) includes minimum information for the terminal to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH includes information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (eg, SIB1 neurology information, information related to SIB1 CORESET, search space information, PDCCH related parameter information, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB in the carrier is transmitted through SIB1), and the like. Here, the SIB1 neurology information is equally applied to some messages used in the random access procedure for accessing the base station after the UE completes the cell search procedure. For example, the neurology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

The aforementioned RMSI may mean System Information Block 1 (SIB1), and SIB1 is periodically broadcast (eg, 160 ms) in the cell. SIB1 includes information necessary for the UE to perform an initial random access procedure, and is periodically transmitted through the PDSCH. In order for the UE to receive SIB1, it must receive neurology information used for SIB1 transmission and CORESET (Control Resource Set) information used for scheduling SIB1 through the PBCH. The UE checks scheduling information for SIB1 by using SI-RNTI in CORESET, and acquires SIB1 on PDSCH according to the scheduling information. SIBs other than SIB1 may be transmitted periodically or may be transmitted according to the request of the terminal.

6 is a diagram for explaining a random access procedure in a radio access technology to which this embodiment can be applied.

Referring to FIG. 6 , upon completion of cell search, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted through the PRACH. Specifically, the random access preamble is transmitted to the base station through a PRACH consisting of continuous radio resources in a specific slot that is periodically repeated. In general, when a UE initially accesses a cell, a contention-based random access procedure is performed, and when random access is performed for beam failure recovery (BFR), a contention-free random access procedure is performed.

The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), a UL grant (uplink radio resource), a temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and a Time Alignment Command (TAC). Since one random access response may include random access response information for one or more terminals, the random access preamble identifier may be included to inform which terminal the included UL Grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, RA-RNTI (Random Access - Radio Network Temporary Identifier).

Upon receiving the valid random access response, the terminal processes information included in the random access response and performs scheduled transmission to the base station. For example, the UE applies the TAC and stores the temporary C-RNTI. In addition, data stored in the buffer of the terminal or newly generated data is transmitted to the base station by using the UL grant. In this case, information for identifying the terminal should be included.

Finally, the terminal receives a downlink message for contention resolution.

<NR CORESET>

The downlink control channel in NR is transmitted in a CORESET (Control Resource Set) having a length of 1 to 3 symbols, and transmits uplink/downlink scheduling information, SFI (Slot Format Index), and TPC (Transmit Power Control) information. .

As such, in NR, the concept of CORESET was introduced in order to secure the flexibility of the system. CORESET (Control Resource Set) means a time-frequency resource for a downlink control signal. The UE may decode the control channel candidates by using one or more search spaces in the CORESET time-frequency resource. Quasi CoLocation (QCL) assumptions for each CORESET are set, and this is used for the purpose of notifying the characteristics of the analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay, which are characteristics assumed by the conventional QCL.

7 is a diagram for explaining CORESET.

Referring to FIG. 7 , CORESET may exist in various forms within a carrier bandwidth within one slot, and CORESET may consist of up to three OFDM symbols in the time domain. In addition, CORESET is defined as a multiple of 6 resource blocks up to the carrier bandwidth in the frequency domain.

The first CORESET is indicated through the MIB as part of the initial bandwidth part configuration to receive additional configuration information and system information from the network. After connection establishment with the base station, the terminal may receive and configure one or more pieces of CORESET information through RRC signaling.

In the present specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals or various messages related to NR (New Radio) can be interpreted in various meanings used in the past or present or used in the future.

The present disclosure provides data channel transmission resources for one or more cells through one DCI (Downlink Control Information) when frequencies are merged in a next-generation/5G radio access network (hereinafter referred to as NR [New Radio] in the present invention). Suggestions on how to allocate That is, a method of allocating PDSCH to one or more cells through one DL assignment DCI or allocating PUSCH to one or more cells through one UL grant DCI is proposed.

New Radio (NR)

Recently, NR conducted in 3GPP was designed to satisfy various QoS requirements required for each segmented and detailed usage scenario as well as an improved data rate compared to LTE. In particular, eMBB (enhancement Mobile BroadBand), mMTC (massive MTC), and URLLC (Ultra Reliable and Low Latency Communications) are defined as representative usage scenarios of NR. As a method to satisfy the requirements for each usage scenario, a flexible frame compared to LTE Structural design is required. Since each usage scenario has different requirements for data rates, latency, reliability, coverage, etc., different numerology ( e.g. subcarrier spacing, subframe, TTI, etc.) based radio resource unit (unit) is designed to efficiently multiplex.

As a method for this, a method for supporting multiplexing based on TDM, FDM or TDM/FDM through one or a plurality of NR component carrier(s) for numerology having different subcarrier spacing values and a scheduling unit in the time domain In the configuration, there was a discussion about how to support more than one time unit. In this regard, in NR, a subframe is defined as a type of time domain structure, and as a reference numerology for defining the corresponding subframe duration, 14 OFDM symbols of the same 15 kHz Sub-Carrier Spacing (SCS)-based normal CP overhead as LTE It was decided to define a single subframe duration composed of Accordingly, in NR, a subframe has a time duration of 1 ms. However, unlike LTE, the NR subframe is an absolute reference time duration, and slots and mini-slots may be defined as time units that are the basis of actual uplink/downlink data scheduling. In this case, the number of OFDM symbols constituting the corresponding slot, the y value, is determined to have a value of y=14 regardless of the SCS value in the case of normal CP.

Accordingly, any slot is composed of 14 symbols, and depending on the transmission direction of the slot, all symbols are used for DL transmission, or all symbols are used for UL transmission, or DL portion + (gap) + It may be used in the form of a UL portion.

In addition, a mini-slot composed of fewer symbols than the slot is defined in any numerology (or SCS), and a short time-domain scheduling interval for uplink/downlink data transmission/reception is set based on this, or slot aggregation A long time-domain scheduling interval for uplink/downlink data transmission/reception can be configured through . In particular, in the case of transmission and reception of latency-critical data such as URLLC, it is difficult to satisfy the latency requirement when scheduling is performed in 1ms (14 symbols)-based slot units defined in a numerology-based frame structure with a small SCS value such as 15kHz. Therefore, for this, a mini-slot composed of fewer OFDM symbols than the corresponding slot is defined, and based on this, scheduling for latency-critical data such as the corresponding URLLC can be defined.

Alternatively, as described above, by multiplexing and supporting numerology having different SCS values in one NR carrier using TDM and/or FDM methods, based on the slot (or mini-slot) length defined for each numerology. A method of scheduling data according to latency requirements is also being considered. For example, when SCS is 60 kHz as shown in FIG. 8 below, since the symbol length is reduced by about 1/4 compared to when SCS is 15 kHz, when one slot is configured with 14 OFDM symbols, the corresponding 15 kHz based slot While the length becomes 1ms, the slot length based on 60kHz is reduced to about 0.25ms.

As such, in NR, by defining different SCS or different TTI lengths, a discussion is ongoing on how to satisfy each requirement of URLLC and eMBB.

Wider bandwidth operations

In the case of the existing LTE system, scalable bandwidth operation for an arbitrary LTC CC (Component Carrier) was supported. That is, according to the frequency deployment scenario, any LTE operator was able to configure a bandwidth of at least 1.4 MHz to a maximum of 20 MHz in configuring one LTE CC, and a normal LTE terminal can configure a bandwidth of 20 MHz for one LTE CC. Transceiver capability was supported.

However, in the case of NR, the design is made to enable support for NR terminals having different transmission/reception bandwidth capabilities through one wideband NR CC, and accordingly, as shown in FIG. It is required to configure one or more bandwidth part(s) composed of the specified bandwidth, and to support flexible wider bandwidth operation through different bandwidth part configuration and activation for each terminal.

Specifically, in NR, one or more bandwidth parts can be configured through one serving cell configured from the viewpoint of the UE, and the UE activates one DL bandwidth part and one UL bandwidth part in the corresponding serving cell to obtain uplink/downlink data It is defined to be used for sending and receiving. In addition, when multiple serving cells are configured in the corresponding UE, that is, even for a UE to which CA is applied, one DL bandwidth part and/or UL bandwidth part is activated for each serving cell, and up/down using the radio resource of the corresponding serving cell. It is defined to be used for sending and receiving link data.

Specifically, an initial bandwidth part for an initial access procedure of a UE is defined in an arbitrary serving cell, and one or more UE-specific bandwidth part(s) are configured through dedicated RRC signaling for each UE, and fallback for each UE A default bandwidth part for operation can be defined.

However, it can be defined to activate and use a plurality of DL and/or UL bandwidth parts at the same time according to the capability and bandwidth part(s) configuration of the UE in any serving cell, but in NR rel-15, any UE It was defined to activate and use only one DL bandwidth part and UL bandwidth part at a time.

DSS (Dynamic Spectrum Sharing)

With the evolution of wireless mobile communication systems, operators are interested in refarming arbitrary LTE frequency bands and utilizing them as NRs. In the process, the DSS technology used for NR signal transmission and reception using some idle resources of the corresponding LTE frequency band was defined through rel-15. Specifically, as a method of transmitting and receiving NR DL or UL signals through any LTE DL subframe or LTE UL subframe of the LTE frequency band, in particular, in the case of the LTE DL subframe, the remaining REs except for the control region and CRS transmission REs in which PDCCH transmission is performed A method for transmitting the NR DL signal through the

As described above for efficient migration from LTE to NR, a design for DSS technology that allows some radio resources to be used for NR signal transmission and reception in an arbitrary LTE frequency band was partially made through 3GPP rel-15.

As an implementation form in DSS, some resources of some LTE DL subframes in LTE frequency band are used for PDCCH, PDSCH and DM RS transmission of NR, and some resources of LTE UL subframe are used for NR PUSCH, PUCCH and DM RS transmission The form and the like may be applied.

In particular, in the case of LTE frequency band, since it is often configured in a low frequency band compared to NR, one base station can support a wider cell coverage in terms of cell coverage. On the other hand, in the case of an NR cell configured in a high frequency band, small for data boosting may be suitable for the cell. In such a cell deployment scenario, for an arbitrary terminal, an NR cell configured based on DSS in an LTE band may be configured as a primary cell (PCell), and an NR cell configured in an NR frequency band may be configured as a secondary cell (SCell).

As such, when an arbitrary NR cell configured based on DSS in the LTE frequency band is configured as a primary cell, and an NR cell configured in the NR frequency band is configured as a secondary cell, in the case of a PCell that supports only self-scheduling, PDCCH due to coexistence with LTE capacity may be insufficient. Accordingly, it is necessary to support the scheduling method for the data channel of the PCell through the SCell, that is, cross-carrier scheduling also for the PCell.

Alternatively, PDSCH or PUSCH allocation information for one or more cells may be transmitted through one scheduling DCI, ie, DL assignment DCI or UL grant.

The present invention proposes a method of allocating PDSCH or PUSCH to one or more cells through one DCI when CA is configured for an arbitrary terminal.

Method 1. Cell-grouping-based multi-cell scheduling method

Through grouping of cells that can be scheduled through one DCI, multi-cell scheduling for cells belonging to the same group can be supported.

As an embodiment of cell grouping for this, grouping between a scheduling cell and a scheduled cell may be set through cross-carrier scheduling setting. That is, the number of cells that can be scheduled through one DCI is limited to 2, and the two cells are limited to a scheduling cell in which DCI transmission is performed and a scheduled cell in which a scheduling DCI for a data channel is transmitted through the corresponding scheduling cell. there is.

Specifically, according to cross-carrier scheduling in the existing CA situation, cross-carrier scheduling in which scheduling for a data channel is performed through a PCell or another scheduling SCell can be applied to any SCell. That is, according to the existing cross-carrier scheduling setting method, any SCell becomes a scheduling cell that transmits a PDCCH including scheduling control information for PDSCH/PUSCH transmitted through another SCell, or is transmitted through the corresponding SCell. The PDCCH including the scheduling control information for the PDSCH/PUSCH could operate as a scheduled cell in the form of being transmitted through another SCell or PCell or PSCell.

For an arbitrary SCell, cross-carrier scheduling was set through an RRC message. The RRC message format for setting the corresponding cross-carrier scheduling is as follows. Accordingly, according to the existing cross-carrier scheduling setting method, in the case of PCell and PSCell, the setting value through schedulingCellInfo is limited to 'own'. As a scheduled cell in which cross-carrier scheduling from

In this way, when CA is configured in an arbitrary terminal, whether or not scheduling control information for a corresponding cell will be transmitted through the corresponding cell through the cross-carrier scheduling configuration information for each cell (that is, the scheduling cell is 'own'). The self-scheduling method set to ') or whether to be transmitted through another cell (ie, the cross-carrier scheduling method in which the scheduling cell is set to 'other') was set.

In addition, when an arbitrary cell is set to 'own', whether to transmit scheduling control information to another cell through the corresponding cell, that is, whether to operate as a scheduling cell according to cross-carrier scheduling setting, is set through the cif-Presence.

In this method, when an arbitrary cell is configured as a scheduling cell, a method for supporting multi-cell scheduling through 1:1 grouping with a scheduled cell(s) whose scheduling is performed through the corresponding cell is proposed.

As a method for this, when an arbitrary cell is configured as a scheduling cell, it can be defined to set whether multi-cell scheduling is supported through additional mcif-Presence configuration. That is, when an arbitrary cell is configured as a scheduling cell and mcif-Presecnce is configured, the scheduling DCI (ie, DL assignment DCI or UL grant) transmitted through the corresponding scheduling cell includes the mci information area. The corresponding mci is an information area for indicating whether the corresponding scheduling DCI includes multi-cell scheduling information. When the corresponding mci is indicated (that is, when mci is set to '1'), the corresponding DCI is scheduled It can be defined to include resource allocation information for the corresponding scheduling cell in addition to the resource allocation information for the cell. For example, if cell A, cell B, and cell C are configured for an arbitrary terminal, cell A is configured as a scheduling cell, and cell B and cell C are configured as scheduled cells for which scheduling is performed through cell A, respectively, the base station can configure mcif-presence through cross-carrier scheduling configuration information for cell A. When mcif-presence for Cell A is configured, scheduling DCI transmitted through cell A should include mcif, and it can be defined that multi-cell scheduling is performed through the combination of the corresponding mcif information and cif. That is, whether the corresponding scheduling DCI is scheduling information for cell A, cell B, or cell C is indicated through cif. In the case of scheduling information for cell B or cell C, additionally mcif indicates whether single cell scheduling information for cell B or cell C or multi-cell scheduling information for cell A+Cell B or cell A+Cell C, including scheduling information for cell A, which is an additional scheduling cell. can be defined to

As another method, the scheduled cell may be set to always be scheduled including the scheduling cell. That is, in the above scheme, if mcif-Presence is set through the cross-carrier scheduling setting for the scheduling cell, and multi-cell scheduling is dynamically indicated through DCI through this, the cross-carrier scheduling setting for the scheduled cell is conversely configured. It can be defined that multi-cell scheduling is configured through the That is, as in the above example, cell A, cell B, and cell C are configured for an arbitrary terminal, cell A is configured as a scheduling cell, and cell B and cell C are scheduled cells for which scheduling is performed through cell A, respectively. If configured, the base station may additionally include multi-cell scheduling configuration information in addition to schedulingCellID information and cif-inschedulingCell information through cross-carrier scheduling configuration information for cell B or Cell C. Accordingly, depending on whether the corresponding multi-cell scheduling is set, it is determined whether the scheduled cell will be scheduled for single cell or multi-cell scheduling together with the scheduling cell. That is, if the corresponding multi-cell scheduling is not configured, and as before, if the cif of the scheduling DCI transmitted through the corresponding cell A indicates cell B or cell C, the corresponding DCI is a single data for cell B or cell C, respectively. Only cell scheduling information is included. Conversely, when multi-cell scheduling is configured for an arbitrary scheduled cell, the corresponding scheduled cell may be defined to be scheduled together with cell A, which is a scheduling cell. For example, when multi-cell scheduling is configured through the cross-carrier scheduling configuration information for cell B, the scheduling control information for the corresponding cell B can be defined to include the scheduling control information for the cell A, which is the scheduling cell. there is. That is, when the cif of the scheduling DCI transmitted through cell A indicates cell B, the corresponding scheduling DCI may be defined to include the scheduling information for cell A together with the scheduling information for cell B.

In the above, a method for supporting multi-cell scheduling only for up to two cells by limiting to one scheduling cell + one scheduled cell when configuring multi-cell scheduling is proposed.

As another method, in multi-cell scheduling, the number of cells or the maximum number of cells that can be scheduled through one scheduling DCI may be set by the base station. For example, for any scheduling cell, the number of cells for which scheduling is performed through one scheduling DCI transmitted through the corresponding cell may be set, or the maximum number of cells that can be scheduled may be set. Specifically, when the number of cells is set, the scheduling DCI transmitted through the corresponding scheduling cell includes scheduling control information corresponding to the set number of cells. To this end, the base station can configure multi-cell scheduling for an arbitrary terminal through RRC signaling, and in this case, it can include configuration information on the number of cells for which scheduling is performed through the single scheduling DCI. In addition, the RRC message for configuring the multi-cell scheduling may include cgif-inschedulingcell information. A corresponding cell group indication field (cgif) is cell group information indicated through scheduling DCI, and one cell group includes cells corresponding to the set number of cells. For example, if four cells of cell A, cell B, cell C, and cell D are configured for an arbitrary terminal and cell A is to be configured as a scheduling cell, the base station sends an RRC message for multi-cell scheduling configuration. cell A may be configured as a scheduling cell through For example, when N=3 is set, it means that scheduling for three cells is performed through one scheduling DCI, and the payload size of the scheduling DCI is determined accordingly. In addition, according to this, multi-cell scheduling information for cell B, cell C, and cell D is to include cgif configuration information along with the scheduling cell ID in which scheduling for the corresponding cell is performed. In this case, one or more pieces of cgif information may be set in one cell. That is, one cell may belong to one or more cell groups. Accordingly, the scheduling DCI transmitted from the corresponding scheduling cell, that is, cell A, includes cgif, and the cell group scheduled through the corresponding DCI is indicated through the corresponding cgif.

However, in this case, as above, all cell groups may be defined to necessarily include a scheduling cell.

Alternatively, as described above, the maximum number of cells that can be scheduled through one DCI may be configured through multi-cell scheduling configuration information. In this case, the Nmax value, which is the maximum value of the number of cells, is set through the RRC message for multi-cell scheduling to be the same as the number of cells, and one cell group includes a number of cell(s) less than or equal to Nmax. can be composed of Hereinafter, RRC signaling for specific multi-cell scheduling configuration can be applied in the same way, except that when the number of cells is set, the number of cells compared to the number of cells, the maximum number of cells, the N value is set, and the Nmax value is set. there is.

Additionally, as described above, the multi-cell scheduling configuration may be transmitted in the form of a cross-carrier scheduling configuration RRC message, or a separate RRC message for multi-cell scheduling may be defined.

Method 2. Dynamic indication without cell grouping

It can be defined to transmit cell indication information in which scheduling is dynamically performed through DCI without separate cell grouping as in the above scheme 1.

As a method for this, one scheduling DCI for multi-cell scheduling may be defined to include cell indication information for indicating a cell in which scheduling is performed through the corresponding DCI, and the cell indication information may be bitmap information. . That is, when CA is configured for an arbitrary terminal, an arbitrary scheduling cell for multi-cell scheduling may be configured by the base station. Accordingly, when an arbitrary cell is configured as a scheduling cell for multi-cell scheduling, the base station may transmit multi-cell scheduling DCI including scheduling control information for one or more cells through the corresponding cell. The multi-cell scheduling DCI is configured to include bitmap information for indicating one or more cells for which scheduling is performed through the corresponding DCI. In this case, the bitmap size for indicating the corresponding cell may be included in the RRC message for configuring the corresponding multi-cell scheduling. For example, the bitmap size configuration information is transmitted directly or configuration information on the maximum number of cells that can be scheduled through one DCI and configuration information on the Nmax value is transmitted, and accordingly, the corresponding bitmap size and the payload of the multi-cell scheduling DCI are transmitted accordingly. size can be determined. A scheduled cell scheduled through the corresponding multi-cell scheduling DCI is also configured through the RRC message for the multi-cell scheduling. In this case, the corresponding scheduled cell configuration information may include information on the location of a bit indicating a corresponding cell in bitmap information for cell indication together with scheduling cell ID information through which the multi-cell scheduling DCI is transmitted.

However, the multi-cell scheduling RRC message may be defined as a separate RRC message or as a form of the cross-carrier scheduling RRC message.

10 is a diagram showing the configuration of the base station 1000 according to another embodiment.

Referring to FIG. 10 , the base station 1000 according to another embodiment includes a controller 1010 , a transmitter 1020 , and a receiver 1030 .

In the method for scheduling a data channel in a wireless mobile communication system required to carry out the present invention, the controller 1010 is configured to, when the PCell is configured in the first frequency band and the SCell in the second frequency band The SCell transmits a PDCCH including scheduling control information for a data channel transmitted through another SCell or transmits a PDCCH including scheduling control information for a data channel transmitted through the one SCell to the PSCell or the other SCell. Controls the overall operation of the base station 1000 according to the method configured to receive through.

The transmitter 1020 and the receiver 1030 are used to transmit/receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

11 is a diagram showing the configuration of a user terminal 1100 according to another embodiment.

Referring to FIG. 11 , a user terminal 1100 according to another embodiment includes a receiver 1110 , a controller 1120 , and a transmitter 1130 .

The receiver 1110 receives downlink control information, data, and a message from the base station through a corresponding channel.

In addition, in the method of scheduling a data channel in a wireless mobile communication system necessary for carrying out the present invention, the controller 1120 is configured to configure one PCell in the first frequency band and SCell in the second frequency band The SCell of the SCell transmits a PDCCH including scheduling control information for a data channel transmitted through another SCell or transmits a PDCCH including scheduling control information for a data channel transmitted through the one SCell to the PSCell or the other Controls the overall operation of the user terminal 1100 according to a method configured to receive through the SCell.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through a corresponding channel.

The above-described embodiments may be supported by standard documents disclosed in at least one of IEEE 802, 3GPP and 3GPP2, which are wireless access systems. That is, steps, configurations, and parts not described in order to clearly reveal the present technical idea among the present embodiments may be supported by the above-described standard documents. In addition, all terms disclosed in this specification can be described by the standard documents disclosed above.

The above-described embodiments may be implemented through various means. For example, the present embodiments may be implemented by hardware, firmware, software, or a combination thereof.

In the case of implementation by hardware, the method according to the present embodiments may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), FPGAs (Field Programmable Gate Arrays), may be implemented by a processor, a controller, a microcontroller or a microprocessor.

In the case of implementation by firmware or software, the method according to the present embodiments may be implemented in the form of an apparatus, procedure, or function that performs the functions or operations described above. The software code may be stored in the memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may transmit/receive data to and from the processor by various well-known means.

Also, as described above, terms such as "system", "processor", "controller", "component", "module", "interface", "model", or "unit" generally refer to computer-related entities hardware, hardware and software. may mean a combination of, software, or running software. For example, the aforementioned component may be, but is not limited to, a process run by a processor, a processor, a controller, a controlling processor, an object, a thread of execution, a program, and/or a computer. For example, both an application running on a controller or processor and a controller or processor can be a component. One or more components may reside within a process and/or thread of execution, and the components may be located on one device (eg, a system, computing device, etc.) or distributed across two or more devices.

The above description is merely illustrative of the technical spirit of the present disclosure, and various modifications and variations will be possible without departing from the essential characteristics of the present disclosure by those skilled in the art to which the present disclosure pertains. In addition, the present embodiments are not intended to limit the technical spirit of the present disclosure, but to explain, and thus the scope of the present technical spirit is not limited by these embodiments. The protection scope of the present disclosure should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present disclosure.

Claims (1)

A method for scheduling a data channel in a wireless mobile communication system, the method comprising:
When the PCell is configured in the first frequency band and the SCell is configured in the second frequency band, one SCell transmits a PDCCH including scheduling control information for a data channel transmitted through another SCell, or the one SCell A method configured to receive a PDCCH including scheduling control information for a data channel transmitted through the PSCell or the other SCell.

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