阅读说明：本技术 用户终端以及基站 (User terminal and base station ) 是由 松村祐辉 柿岛佑一 永田聪 王静 侯晓林 于 2018-07-13 设计创作，主要内容包括：本公开的一方式所涉及的用户终端的特征在于,具有：接收单元,接收PDCCH(物理下行链路控制信道(Physical Downlink Control Channel))；以及控制单元,在低延迟波束选择通过高层信令被设定的情况下,设想为在该PDCCH的发送以及特定的信道的发送接收中使用相同的空间域滤波器。根据本公开的一方式,能够快速地切换信道的TCI状态或者波束。(A user terminal according to an aspect of the present disclosure includes: a reception unit configured to receive a PDCCH (Physical Downlink Control Channel); and a control unit configured to assume that the same spatial filter is used for transmission and reception of the PDCCH and transmission and reception of a specific channel when low-delay beam selection is set by higher-layer signaling. According to an aspect of the present disclosure, a TCI state or a beam of a channel can be rapidly switched.)

1. A user terminal, comprising:

a reception unit that receives a Physical Downlink Control Channel (PDCCH); and

when the low-delay beam selection is set by the higher layer signaling, the control section assumes that the same spatial filter is used for transmission of the PDCCH and transmission/reception of a specific channel.

2. The user terminal of claim 1,

the control unit assumes that the same downlink spatial domain transmission filter is used for transmission of the PDCCH and transmission of a Physical Downlink Shared Channel (PDSCH).

3. The user terminal of claim 1 or claim 2,

the control unit is assumed to be configured such that a downlink spatial domain transmission filter used for transmission of the PDCCH is the same as an uplink spatial domain reception filter used for reception of a physical uplink control channel, which is the PUCCH.

4. A base station, comprising:

a transmission unit configured to transmit a Physical Downlink Control Channel (PDCCH); and

a control unit that performs the following control: for a user terminal in which low-delay beam selection is set by higher-layer signaling, the same spatial filter is used for transmission of the PDCCH and transmission/reception of a specific channel.

5. The base station of claim 4,

the control unit performs the following control: the same downlink spatial domain transmission filter is used for transmission of the PDCCH and transmission of the PDSCH, i.e., the physical downlink shared channel.

6. The base station of claim 4 or claim 5,

the control unit performs the following control: the same spatial domain transmission filter is used for transmission of the PDCCH and reception of the physical uplink control channel, which is the PUCCH.

Technical Field

The present disclosure relates to a user terminal and a base station in a next generation mobile communication system.

Background

In a UMTS (Universal Mobile Telecommunications System) network, Long Term Evolution (LTE) is standardized for the purpose of higher data rate, lower latency, and the like (non-patent document 1). In addition, LTE-a (LTE-Advanced, LTE rel.10, 11, 12, 13) is standardized for the purpose of further large capacity, Advanced, and the like of LTE (LTE rel.8, 9).

Successor systems of LTE are also investigated (e.g. also referred to as FRA (Future Radio Access)), 5G (fifth generation mobile communication system), 5G + (plus), NR (New Radio), NX (New Radio Access), FX (Future generation Radio Access), LTE rel.14 or 15 and beyond, etc.).

Documents of the prior art

Non-patent document

Non-patent document 13 GPP TS 36.300 V8.12.0 "Evolved Universal Radio Access (E-UTRA) and Evolved Universal Radio Access Network (E-UTRAN); (ii) an Overall description; stage 2(Release 8) ", 4 months 2010

Disclosure of Invention

Problems to be solved by the invention

In future radio communication systems (hereinafter, abbreviated as NR), it is considered to control Transmission/reception processing of a channel based on a Transmission setting Indicator (TCI) state.

However, the TCI state control method that has been studied so far for Rel-15 NR requires a relatively long time for changing the TCI state, or communication overhead. Therefore, in a case where the TCI state needs to be frequently changed, communication throughput may be reduced.

Therefore, an object of the present disclosure is to provide a user terminal and a base station capable of rapidly switching a TCI state or a beam of a channel.

Means for solving the problems

A user terminal according to an aspect of the present disclosure includes: a reception unit configured to receive a PDCCH (Physical Downlink Control Channel); and a control unit configured to assume that the same spatial filter is used for transmission and reception of the PDCCH and transmission and reception of a specific channel when low-delay beam selection is set by higher-layer signaling.

Effects of the invention

According to an aspect of the present disclosure, a TCI state or a beam of a channel can be rapidly switched.

Drawings

Fig. 1 is a diagram showing an example of PDCCH beam management in Rel-15 NR.

Fig. 2 is a diagram showing an example of low-delay beam selection.

Fig. 3 is a diagram showing an example of PDCCH beam management in a case where low-delay beam selection is set.

Fig. 4 is a diagram showing an example of PUCCH or PUSCH resources for reporting CSI measurement results.

Fig. 5 is a diagram showing an example of PDSCH beam management in a case where low-delay beam selection is set.

Fig. 6 is a diagram illustrating an example of PUCCH beam management in a case where low-delay beam selection is set.

Fig. 7 is a diagram showing another example of PUCCH beam management in a case where low-delay beam selection is set.

FIG. 8 is a graph showing a graph based on T_offsetFig. is a diagram of an example of an assumption of a base station transmission beam of the PDCCH.

FIG. 9 is a graph showing a graph based on T_offsetFig. is a diagram of another example of the base station transmission beam of the PDCCH.

FIG. 10 is a graph showing a graph based on T_offsetFig. of yet another example of the base station transmission beam of the PDCCH in (1).

Fig. 11 is a diagram showing an example of a schematic configuration of a radio communication system according to an embodiment.

Fig. 12 is a diagram showing an example of the overall configuration of a base station according to an embodiment.

Fig. 13 is a diagram showing an example of a functional configuration of a base station according to an embodiment.

Fig. 14 is a diagram showing an example of the overall configuration of a user terminal according to an embodiment.

Fig. 15 is a diagram showing an example of a functional configuration of a user terminal according to an embodiment.

Fig. 16 is a diagram showing an example of hardware configurations of a base station and a user terminal according to an embodiment.

Detailed Description

(CORESET)

In NR, in order to transmit a physical layer Control signal (e.g., Downlink Control Information (DCI)) from a base station to a User terminal (User Equipment (UE)), a Control REsource SET (core: Control REsource SET) is used.

The CORESET is an allocation candidate region of a Control Channel (e.g., PDCCH (Physical Downlink Control Channel)). The CORESET may be configured to include specific frequency domain resources and time domain resources (e.g., 1 or 2OFDM symbols).

The UE may also receive, from the base station, configuration information of CORESET (which may also be referred to as CORESET configuration, CORESET-configuration). The UE can detect the physical layer control signal by monitoring the CORESET set to the terminal itself.

The CORESET setting may be notified by higher layer signaling, for example, or may be represented by a specific RRC information element (may also be referred to as "ControlResourceSet").

Here, the higher layer signaling may be one of RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information, and the like, or a combination thereof, for example.

For example, a MAC Control Element (MAC CE (Control Element)) or a MAC PDU (Protocol Data Unit) may be used for the MAC signaling. The broadcast Information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Minimum System Information (RMSI), or the like.

The CORESET may also be set to a specific number (e.g., 3 or less) per Bandwidth Part (BWP) set to the UE in the serving cell.

Here, BWP is a partial band set in a Carrier (also referred to as a cell, a serving cell, a Component Carrier (CC), or the like), and is also referred to as a partial band. The BWP may include Uplink (UL) BWP (UL BWP, Uplink) and Downlink (DL BWP, Downlink) BWP (DL BWP, Downlink). Each BWP given the above specified number of CORESET may also be a DL BWP.

The CORESET setting may mainly include information of resource association setting and RS association setting of the PDCCH. For the UE, the following parameters may also be given by higher layer signaling (CORESET setup) for CORESET # p set to each DL BWP (e.g., 0 ≦ p < 3). That is, the following parameters may be notified (set) to the UE for each CORESET:

an Identifier of CORESET (CORESET-ID (Identifier))),

the scramble ID of a DeModulation Reference Signal (DMRS) for PDCCH,

the duration of the CORESET (e.g., time duration, CORESET-time duration) indicated by the number of consecutive (consecutive) symbols,

resource Allocation in the Frequency domain (Frequency-domain Resource Allocation) (e.g., information indicating a specific number of Resource blocks constituting CORESET (CORESET-freq-dom)),

a mapping type (information indicating interleaving or non-interleaving) from a Control Channel Element (CCE) within the CORESET to a Resource Element Group (REG) (e.g., CORESET-CCE-to-REG-mapping-type),

information (e.g., CORESET-REG-bundle-size) indicating the size of a group (REG bundle) containing a certain number of REGs (REG bundle),

information (e.g., CORESET-Shift-index) indicating a Cyclic Shift (CS: Cyclic Shift, CS amount, or CS index) for the interleaver of the REG bundle,

a Transmission setting instruction (Transmission setting Indicator (TCI)) state for PDCCH (also referred to as QCL information (antenna port QCL) of an antenna port of DMRS for PDCCH reception),

an indication of the presence or absence of a TCI field (e.g., TCI-PresentInDCI) in DCI (e.g., DCI format 1_0 or DCI format 1_1) transmitted through the PDCCH in CORESET # p.

"CORESET-ID # 0" may also indicate CORESET set using the MIB (which may also be referred to as initial CORESET, default CORESET, or the like).

The Search region and the Search method of PDCCH candidates (PDCCH candidates) are defined as a Search Space (SS). The UE may also receive search space configuration information (which may also be referred to as search space configuration) from the base station. The search space setting may be notified by higher layer signaling (RRC signaling, etc.), for example.

The UE monitors CORESET based on the search space settings. The UE can determine the correspondence between the CORESET and the search space based on the CORESET-ID included in the search space setting. A CORESET may also be associated with one or more search spaces.

(QCL/TCI)

In NR, it is studied that a UE controls reception processing (e.g., demapping, demodulation, decoding, reception beamforming, etc.) and transmission processing (e.g., mapping, modulation, coding, precoding, transmission beamforming, etc.) of a channel (e.g., PDCCH, PDSCH, PUCCH, etc.) based on information (QCL information) related to Quasi-Co-Location (QCL).

Here, the QCL is an indicator indicating the statistical properties of the channel. For example, when a certain signal/channel and another signal/channel are in a QCL relationship, it may be assumed that at least one of doppler shift (doppler shift), doppler spread (doppler spread), average delay (average delay), delay spread (delay spread), and Spatial Parameter (Spatial Parameter) (for example, Spatial Rx Parameter)) is the same (at least one of them is QCL) among the different signals/channels.

The spatial reception parameters may correspond to reception beams (for example, reception analog beams) of the UE, or may be determined based on the spatial QCL. QCL (or at least one element of QCL) in the present disclosure may also be replaced with sQCL (spatial QCL).

QCLs may also be specified with multiple types (QCL types). For example, it can be assumed that four QCL types a-D of the same parameter (or parameter set) may also be set, which are indicated below:

QCL type A: doppler shift, doppler spread, mean delay, and delay spread,

QCL type B: the doppler shift and the doppler spread are then combined,

QCL type C: the average delay and the doppler shift are then determined,

QCL type D: the space receives the parameters.

The TCI state (TCI-state) may also represent (and may also contain) QCL information. The TCI state (and/or QCL information) may be information related to the QCL of a channel to be subjected to the qci (or a Reference Signal (RS) for the channel) and other signals (for example, other Downlink Reference signals (DL-RS) and may include at least one of information related to DL-RSs that are in a QCL relationship (DL-RS-related information) and information indicating the QCL type (QCL type information)).

The DL-RS association information may include at least one of information indicating DL-RS that is in QCL relationship and information indicating resources of the DL-RS. For example, when a plurality of reference signal sets (RS sets) are set for the UE, the DL-RS association information may indicate at least one of a DL-RS having a QCL relationship with a channel (or a port for the channel) among RSs included in the RS sets, resources for the DL-RS, and the like.

Here, at least one of the RS for Channel and the DL-RS may be at least one of a Synchronization Signal (SS), a Broadcast Channel (PBCH), a Synchronization Signal Block (SSB), a Mobility Reference Signal (MRS), a Channel state Information Reference Signal (CSI-RS), a DeModulation Reference Signal (DMRS), a beam-specific Signal, and the like, or a Signal formed by expanding or changing the same (for example, a Signal formed by changing at least one of density and period).

The synchronization Signal may be at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS), for example. The SSB may be a signal block including a synchronization signal and a broadcast channel, and may be referred to as an SS/PBCH block or the like.

Information on QCLs of the PDCCH (or DMRS antenna ports associated with the PDCCH) and the specific DL-RS may also be referred to as PDCCH TCI status or the like.

The UE may also determine the TCI status for the UE-specific pdcch (core set) based on RRC signaling and MAC CE.

For example, one or a plurality of (K) TCI states may be set for each CORESET by higher layer signaling (ControlResourceSet information element) for the UE. Furthermore, the UE may also activate (activate) one or more TCI states using the MAC CE for each CORESET. This MAC CE may also be referred to as a TCI status Indication MAC CE (TCI State Indication for UE-specific PDCCH MAC CE) for UE-specific PDCCH. The UE may also perform monitoring of the CORESET based on the activated TCI status corresponding to the CORESET.

The TCI state may also correspond to a beam. For example, the UE may also assume that PDCCHs for different TCI states are transmitted using different beams.

Information related to QCLs of PDSCH (or DMRS antenna ports associated with PDSCH) and specific DL-RS may also be referred to as TCI status for PDSCH, etc.

The UE may be notified (set) of M (M ≧ 1) TCI states (QCL information for M PDSCHs) for the PDSCH by higher layer signaling. In addition, the number M of TCI states set to the UE may also be limited by at least one of UE capability (UE capability) and QCL type.

The DCI used for scheduling the PDSCH may include a specific field (e.g., may be referred to as a field for TCI, a TCI field, a TCI status field, etc.) indicating a TCI status (QCL information for the PDSCH). The DCI may also be used for scheduling PDSCH of one cell, and may also be referred to as DL DCI, DL allocation, DCI format 1_0, DCI format 1_1, or the like, for example.

In addition, when the DCI includes a TCI field of x bits (for example, x is 3), the base station may set the maximum 2 to the DCI^xThe (e.g., 8 TCI states in the case of x — 3) kinds of TCI states are preset to the UE using higher layer signaling. The value of the TCI field (TCI field value) in the DCI may also indicate one of TCI states preset by higher layer signaling.

When more than 8 TCI states are set for the UE, less than 8 TCI states may be activated (or designated) using the MAC CE. The MAC CE may also be referred to as a TCI state Activation/Deactivation MAC CE (TCI States Activation/Deactivation for UE-specific PDSCH MAC CE) for the UE-specific PDSCH. The value of the TCI field within the DCI may also indicate one of the TCI states that is activated by the MAC CE.

The UE may also determine the QCL of the PDSCH (or DMRS port of the PDSCH) based on the TCI status indicated by the TCI field value in the DCI. For example, the UE may control the reception process (e.g., decoding, demodulation, etc.) of the PDSCH assuming that the DMRS port (or DMRS port group) of the PDSCH serving as the serving cell and the DL-RS corresponding to the TCI state notified through the DCI are QCL.

(Beam management)

However, in Rel-15 NR, a method of Beam Management (BM: Beam Management) has been studied so far. In this beam management, beam selection is being studied based on L1-RSRP reported by the UE. Changing (switching) a beam of a certain signal/channel corresponds to changing the TCL state (QCL) of the signal/channel.

The beam selected by the beam selection may be a transmission beam (Tx beam) or a reception beam (Rx beam). The beam selected by the beam selection may be a beam of the UE or a beam of the base station.

The UE may include L1-RSRP in the CSI and report the CSI using an Uplink Control Channel (PUCCH) or an Uplink Shared Channel (PUSCH).

The CSI may include at least one of a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), a SS/PBCH Block Resource Indicator (SS/PBCH Block Indicator), a Layer Identifier (LI), a Rank Identifier (RI), a Rank Indicator (L) and L1-RSRP.

The measurement results (e.g., CSI) reported for beam management may also be referred to as beam measurements (beam measurement), beam measurement results, beam measurement reports (beam measurement report), and the like.

The UE may measure the channel state using the CSI measurement resource to derive L1-RSRP. The CSI measurement resource may be at least one of a SS/PBCH block resource, a CSI-RS resource, another reference signal resource, and the like. The setting information of the CSI measurement report may also be set to the UE using higher layer signaling.

The CSI measurement report setting information (CSI-MeasConfig or CSI-resourceconconfig) may include information such as one or more Non-Zero Power (NZP: Non Zero Power) CSI-RS resource sets (NZP-CSI-RS-resources set), one or more Zero Power (ZP) CSI-RS resource sets (ZP-CSI-RS-resources set) (or CSI-IM (Interference Management) resource sets (CSI-IM-resources set)), and one or more SS/PBCH block resource sets (CSI-SSB-resources set) for CSI measurement.

The information of each resource set may include information related to repetition (repetition) of resources in the resource set. The information related to the repetition may also indicate, for example, 'on' or 'off'. In addition, 'on' may also be denoted as 'enabled or valid,' and 'off' may also be denoted as 'disabled or invalid'.

For example, for a resource set whose "on" is repeatedly set, the UE may assume that the same downlink spatial domain transmission filter (same downlink spatial domain transmission filter) is used for the resources in the resource set. In this case, the UE may also assume that resources within the resource set are transmitted using the same beam (e.g., from the same base station).

For a resource set whose 'close' is repeatedly set, the following control may be performed: the UE cannot assume (or may not assume) that resources within the set of resources are transmitted using the same downlink spatial domain transmit filter. In this case, the UE may also assume that the resources within the resource set are not transmitted using the same beam (transmitted using different beams). That is, the UE may assume that the base station is performing beam scanning for the resource set for which 'off' is repeatedly set.

Fig. 1 is a diagram showing an example of PDCCH beam management in Rel-15 NR. The NW (network, e.g., base station) determines to switch the TCI state for PDCCH of a certain UE (step S101). The NW transmits DCI for scheduling the PDSCH to the UE using the PDCCH in the earlier (before handover) TCI state (step S102).

The base station transmits the PDSCH including the TCI status indication MAC CE for the UE-specific PDCCH (step S103).

When the DCI is detected, the UE decodes the PDSCH to acquire the MAC CE. Upon receiving the MAC CE, the UE transmits HARQ-ACK (Hybrid Automatic Repeat reQuest Acknowledgement) for the PDSCH to which the MAC CE is provided (step S104). The UE applies an activation (activation) command based on the TCI state of the MAC CE 3 milliseconds after the slot in which the HARQ-ACK is transmitted (step S105).

Thereafter, the base station transmits the PDCCH in accordance with the new (switched) TCI state, and the UE can receive and decode the PDCCH (step S106).

As described above, the control method of the TCI state for PDCCH, which has been studied so far with respect to Rel-15 NR, requires a relatively long time to change the TCI state. In addition, for other channels (PDSCH, PUCCH, and the like), a relatively long time is required for changing the TCI state, and communication overhead is also required. Therefore, in a case where the TCI state needs to be frequently changed, for example, a delay involved in the change becomes a problem, and communication throughput may be reduced.

Accordingly, the present inventors have conceived a method of rapidly switching the TCI state or beam of a channel.

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. The radio communication methods according to the respective embodiments may be applied individually or in combination.

(Wireless communication method)

< setting of Low delay Beam selection >

In one embodiment, when the low-delay beam selection is set by the higher layer signaling, the UE may assume that the TCI state for the PDCCH is not set.

Fig. 2 is a diagram showing an example of low-delay beam selection. The NW determines to switch the TCI state for PDCCH of a certain UE (step S201). After step S201, the NW transmits the PDCCH in the new (switched) TCI state to the UE without performing PDCCH (dci) transmission, pdsch (mac ce) transmission, and the like in the earlier TCI state as in fig. 1 (step S202).

In addition, the low delay beam selection (low delay beam selection) may also be referred to as fast beam selection (fast beam selection), beam selection without TCI state (beam selection w/o TCI state), beam selection type ii (beam selection type ii), TCI state designation type 2, and the like.

On the other hand, in the method of indicating the TCI state using RRC + MAC CE as described in fig. 1, the high latency beam selection (high latency beam selection) may be referred to as low speed beam selection (slow beam selection), beam selection per TCI state (beam selection w TCI state), beam selection type i (beam selection type i), TCI state designation type 1, Rel-15 beam selection, and the like.

The UE may also assume to select according to a high delay beam when the low delay beam selection is not set. In this case, the UE can grasp the transmission beam of the base station by being set with the TCI state.

That is, the UE can switch the low delay beam selection and the high delay beam selection through higher layer signaling.

< receiving processing of PDCCH >

Even when the TCI state is not set as in fig. 2, the UE may attempt blind decoding of the PDCCH for the assumed TCI state, for example, and decode the PDCCH. The UE may also perform reception processing (demodulation, decoding, etc.) of the PDCCH assuming that a specific signal/channel (for example, at least one of the set SS/PBCH block and CSI-RS) and the DMRS of the PDCCH are QCL.

Further, the UE to which the low delay beam selection is set may assume that the UE reception beam for the PDCCH is the same as the UE reception beam corresponding to the latest reported beam measurement result. The UE to which the low delay beam selection is set may assume that the base station transmission beam for the PDCCH is the same as the base station transmission beam corresponding to the latest beam measurement result reported by the UE. In other words, the UE in which the low-delay beam selection is set may assume that the TCI state for the PDCCH is the same as the TCI state corresponding to the latest reported beam measurement result (QCL is used for the signal/channel used for measurement corresponding to the latest reported beam measurement result).

Based on such an assumption, the UE can monitor PDCCH (core) using a specific UE reception beam without being notified of the TCI status for PDCCH.

In addition, the "low delay beam selection is set" in the present disclosure may be replaced with "low delay beam selection is set and the repetition of resources in the CSI measurement resource set is set to" off' ", or" low delay beam selection is set and the base station applies transmission beam scanning to the CSI measurement resource ", and the like.

Further, CORESET in the present disclosure may also be replaced with at least one of a search space, a search space set, PDCCH candidates, and the like.

Fig. 3 is a diagram showing an example of PDCCH beam management in a case where low-delay beam selection is set. The UE assumes that low-delay beam selection is set, and further, RS #1 to #4 that are repeatedly turned off are set as reference signals for CSI measurement.

The base station transmits RS #1 to #4 to the UE (step S301). For the transmission of the RS, the base station may also apply transmit beam scanning. The UE may assume the same UE reception beam for RS #1- #4 that is repeatedly turned 'off' (may perform reception processing using the same UE reception beam).

The UE transmits measurement reports (e.g., CSI) based on the measurement results of the RSs #1 to #4 using the PUCCH or the PUSCH (step S302). The UE may also transmit the measurement result of the best beam among RSs #1- #4, for example. The measurement report will be described later.

The base station may determine to switch the TCI state for PDCCH of the UE at an arbitrary timing (step S303). The base station may transmit the PDCCH transmitted by any CORESET after step S303 using the new base station transmission beam (TCI state) (step S304).

The UE may use the same UE reception beam as the UE reception beam corresponding to the latest beam measurement result reported in step S302 (the UE reception beam used in step S301) in the CORESET reception in step S304.

< Beam measurement report >

An example of the measurement report in step S302 will be described. The UE may perform at least one of channel quality measurement and interference measurement based on at least one of the CSI measurement resource and the interference measurement resource, and report (transmit) the measurement result (for example, CSI) using the PUCCH or the PUSCH.

The CSI measurement resource and the interference measurement resource may be, for example, the resource of the SS/PBCH block, the resource of the CSI-RS, or the like. The base station may also perform transmission or reception beam selection based on the reporting result of the UE. Hereinafter, the CSI measurement and the interference measurement are collectively referred to as CSI measurement.

The CSI measurement/reporting in the present disclosure may also be replaced with at least one of measurement/reporting for beam management, beam measurement/reporting, radio link quality measurement/reporting, and the like.

The result of the channel quality measurement may include L1-RSRP, for example.

The Interference measurement result may include SINR (Signal to Interference plus Noise Ratio), SNR (Signal to Noise Ratio), RSRQ (Reference Signal Received Quality), and other Interference-related indicators (for example, any indicator other than L1-RSRP). The SINR, SNR, and RSRQ may be referred to as L1-SINR, L1-SNR, L1-RSRQ, respectively.

When the UE reports at least one of L1-RSRP, L1-RSRQ, L1-SINR, and the result of channel quality measurement, a specific number of maximum values (a specific number of values from the maximum value) may also be reported. In case the UE reports at least one of the results of the interference measurements, a certain number of minimum values (a certain number of values from the minimum) may also be reported. When the UCI includes a plurality of values, one value and a difference between the one value and another value may be included.

The UE may also be notified of information related to the particular number using higher layer signaling, physical layer signaling, or a combination thereof. The specific number may be, for example, 1, 2, 4, etc. The specific number may also be set to different values in the reporting of channel quality measurements and the reporting of interference measurements.

The UE may also report a beam index (beam ID), a CSI measurement resource ID (e.g., SSBRI, CRI), or an index of a CSI measurement signal (e.g., SSB index, CSI-RS ID) corresponding to at least one of a specific number of the largest L1-RSRP, L1-RSRQ, L1-SINR, and a result of the channel quality measurement.

The UE may also report a beam index (beam ID), a CSI measurement resource ID (e.g., SSBRI, CRI), or an index of a CSI measurement signal (e.g., SSB index, CSI-RS ID) corresponding to at least one of the results of the certain number of minimum interference measurements.

The PUCCH or PUSCH resource may correspond to a beam index, CSI measurement resource ID, or index of a CSI measurement signal. The UE may report the information on the beam index or the like by using a specific PUCCH/PUSCH resource without explicitly reporting the information, and may implicitly notify the base station of the beam index or the like.

For example, the UE may be set with X (e.g., 8) PUCCH/PUSCH resources corresponding to beams/resources/IDs for CSI measurement by higher layer signaling. The UE may also transmit the CSI report using X (e.g., 2) resources corresponding to the beam/resource/ID of the report target among the X resources.

The PUCCH/PUSCH resources set for CSI reporting may correspond to at least one of time resources, frequency resources, Code resources (e.g., cyclic shift, Orthogonal Cover Code (OCC)), and the like.

Fig. 4 is a diagram showing an example of PUCCH or PUSCH resources for reporting CSI measurement results. In this example, the UE is configured with eight PUCCH/PUSCH resources for reporting, corresponding to the CSI measurement resource. For example, the resource may be a resource for a Scheduling Request (SR) for PUCCH format 0.

The set resources correspond to beams a-h, respectively. In fig. 4, the UE transmits SR resources corresponding to beams c and f in order to report the results of these beams.

The above-mentioned "maximum of the specific number" may be replaced with "the measurement result is equal to or more than the threshold value", "the measurement result is equal to or more than the threshold value, and the specific number is maximum", or the like. Further, "the specified number is the smallest" described above may be replaced with "the measurement result is smaller than the threshold", "the measurement result is smaller than the threshold, and the specified number is the smallest", or the like. The threshold value here may be set by higher layer signaling or may be determined by specification.

In case the UE reports more than one number of measurements to the base station, how the base station decides the beam for the UE may also depend on the installation of the base station.

< channel for control applying no setting of TCI State >

The control associated with low-delay beam selection (e.g., control not setting the TCI state) of the present disclosure may also be applied only to the PDCCH. This is because the above-described problem (delay) for beam selection is assumed to mainly act on beam selection of Rel-15 NR for PDCCH and other channels. In this case, complication of the installation of the UE can be suppressed.

Further, control without setting the TCI state may also be applied to the PDSCH. In this case, the UE may also assume that the PDCCH and the PDSCH are transmitted from the base station using the same transmission beam. By not setting the TCI state for the PDSCH, notification of the TCI state for the PDSCH using DCI, MAC CE, or the like becomes unnecessary, and therefore reduction of communication overhead can be expected.

Further, control without setting the TCI state may also be applied to the PUCCH. In this case, the UE may assume that the transmission beam of the PDCCH of the base station and the reception beam of the PUCCH of the base station are the same beam.

Here, the terms corresponding to the TCI state may also be expressed as spatial relationship (spatial relationship) for the PUCCH. In Rel-15 NR, the PUCCH configuration information (PUCCH-Config information element) of RRC can include spatial relationship information between a specific RS and a PUCCH. The specific RS is at least one of SSB, CSI-RS and a Sounding Reference Signal (SRS).

When the spatial relationship information on the SSB or CSI-RS and the PUCCH is set, the UE may transmit the PUCCH using the same spatial filter as that used for reception of the SSB or CSI-RS. That is, in this case, the UE may assume that the UE reception beam of the SSB or CSI-RS and the UE transmission beam of the PUCCH are the same.

When the spatial relationship information on the SRS and the PUCCH is set, the UE may transmit the PUCCH using the same spatial filter as that used for transmission of the SRS. That is, in this case, the UE may assume that the UE transmission beam for SRS and the UE transmission beam for PUCCH are the same.

In addition, a spatial domain filter used for transmission of the base station, a downlink spatial domain transmission filter (downlink spatial domain transmission filter), and a transmission beam of the base station may be replaced with each other. The spatial domain filter for reception of the base station, the uplink spatial domain receive filter (uplink spatial domain receive filter), and the receive beam of the base station may also be replaced with each other.

In addition, a spatial domain filter for transmission of the UE, an uplink spatial domain transmission filter (uplink spatial domain transmission filter), and a transmission beam of the UE may be replaced with each other. A spatial domain filter for reception of the UE, a downlink spatial domain receive filter (downlink spatial domain receive filter), and a reception beam of the UE may also be replaced with each other.

When more than one piece of spatial relationship information on the PUCCH is set, control is performed such that one PUCCH resource is activated and one PUCCH spatial relationship is activated at a certain time by activating/deactivating a MAC CE (PUCCH spatial relationship Activation/Deactivation MAC CE) by the PUCCH spatial relationship.

The MAC CE may include information such as a serving cell ID, a BWP ID, and a PUCCH resource ID of an application target.

The UE may apply the setting corresponding to the spatial domain filter based on the MAC CE for PUCCH transmission 3 milliseconds after the slot in which the HARQ-ACK for the PDSCH to which the MAC CE is provided is transmitted.

By not setting the spatial relationship to the PUCCH, notification (activation) of the spatial relationship for PUCCH using the MAC CE or the like becomes unnecessary, and therefore reduction of communication overhead can be expected.

Specific examples will be described below.

[ control for not setting TCI State on PDSCH ]

When the low delay beam selection is set by the higher layer signaling, the UE may assume that the PDCCH and the PDSCH are transmitted from the base station using the same transmission beam.

When the PDSCH is Semi-persistently assigned (for example, when the PDSCH is Semi-Persistent Scheduling (SPS)), the UE may assume that the base station transmission beam of the PDSCH is the same as the base station transmission beam of the closest pdcch (coreset).

When the PDSCH is dynamically allocated with resources, the UE may assume that a base station transmission beam for the PDSCH is the same as a base station transmission beam for a pdcch (core) scheduling the PDSCH.

When the low delay beam selection is set by the higher layer signaling, the UE may use the same UE reception beam for receiving the PDCCH and the PDSCH.

When the PDSCH is semi-statically allocated, the UE may receive the PDSCH using the UE reception beam for the latest pdcch (coreset).

When the PDSCH is dynamically allocated with resources, the UE may receive the PDSCH using a UE reception beam for a pdcch (core) scheduling the PDSCH.

When the UE is set to select the low-delay beam, the TCI field included in the DCI may be assumed to be 0 bits. For example, the TCI field of DCI format 1_1 may be 0 bit when the higher layer parameter (TCI-PresentInDCI) indicating that the TCI field is not valid or the higher layer parameter indicating low delay beam selection is valid.

Even when more than eight TCI states are set by higher layer signaling, if low delay beam selection is set, the UE may assume that there is no notification of UE-specific PDSCH-specific TCI state activation/deactivation MAC CE (MAC CE for beam selection of PDSCH) (reception of the MAC CE is not expected).

Fig. 5 is a diagram showing an example of PDSCH beam management in the case where low-delay beam selection is set. Steps S301 to S304 may be the same as in the example of fig. 3, and therefore, redundant description is omitted. In this example, it is assumed that the UE detects DCI scheduling PDSCH in the PDCCH of step S304.

The UE performs a PDSCH reception process based on the DCI (step S305). The UE may assume that the base station transmission beam of the PDSCH in step S305 is the same as the base station transmission beam of the PDCCH in step S304.

The UE may assume that the UE reception beam of the PDSCH in step S305 is the same as the UE reception beam of the PDCCH in step S304.

Furthermore, when the TCI state is not set for the PDCCH, the UE may assume that the UE reception beam for the PDSCH in step S305, the UE reception beam for the PDCCH in step S304, and the UE reception beam corresponding to the latest beam measurement result reported in step S302 (the UE reception beam used in step S301) are the same.

[ control without setting TCI State on PUCCH ]

When the low delay beam selection is set by the higher layer signaling, the UE may use the same beam (the same transmission/reception beam) for transmission/reception of the PDCCH, PDSCH, and PUCCH.

When the PUCCH is semi-statically allocated (for example, when P-CSI report or SP-CSI report), the UE may assume that the base station beam (reception beam) of the PUCCH and the base station beam (transmission beam) of the closest PDCCH or PDSCH are the same.

In the case of PUCCH based on dynamic scheduling (for example, in the case of transmitting HARQ-ACK for PDSCH scheduled by DL assignment via PUCCH), the UE may assume that the base station beam (reception beam) of the PUCCH is the same as the base station beam (transmission beam) of at least one of the PDSCH corresponding to the PUCCH and the PDCCH on which the PDSCH is scheduled.

When the low delay beam selection is set by the higher layer signaling, the UE may assume that the reception beam of the PDCCH and the transmission beam of the PUCCH are the same.

When the PUCCH is semi-statically allocated, the UE may assume that the UE transmission beam for the PUCCH is the same as the UE reception beam for the closest PDCCH or PDSCH.

In the case of PUCCH based dynamic scheduling, the UE may assume that a UE transmission beam for the PUCCH is the same as a UE reception beam for at least one of a PDSCH corresponding to the PUCCH and a PDCCH on which the PDSCH is scheduled.

When the low-delay beam selection is set, the UE may assume that there is no notification of activation/deactivation of the MAC CE in the PUCCH spatial relationship (may not expect reception of the MAC CE).

Fig. 6 is a diagram illustrating an example of PUCCH beam management in the case where low-delay beam selection is set. Steps S301 to S305 may be the same as in the example of fig. 5, and therefore, redundant description is omitted.

The UE transmits HARQ-ACK for the PDSCH received in step S305 (step S306). The UE may assume that the base station reception beam of the PUCCH in step S306, the base station transmission beam of the PDSCH in step S305, and the base station transmission beam of the PDCCH in step S304 are the same.

The UE may assume that the UE transmission beam of the PUCCH in step S306, the UE reception beam of the PDSCH in step S305, and the UE reception beam of the PDCCH in step S304 are the same.

Furthermore, when the TCI state is not set for the PDCCH, the UE may assume that the UE transmission beam of the PUCCH in step S306, the UE reception beam of the PDSCH in step S305, the UE reception beam of the PDCCH in step S304, and the UE reception beam corresponding to the latest beam measurement result reported in step S302 (the UE reception beam used in step S301) are the same.

Fig. 7 is a diagram showing another example of PUCCH beam management in the case where low-delay beam selection is set. Steps S301 to S303 and S306 may be the same as in the example of fig. 6, and therefore, redundant description is omitted. In this example, it is assumed that the UE detects DCI scheduling PDSCH in the PDCCH of step S304. In addition, unlike the example of fig. 6, the DCI includes a field specifying the TCI state for the PDSCH.

The UE performs a PDSCH reception process based on the DCI (step S405). The UE may not assume that the base station transmission beam for the PDSCH in step S405 is the same as the base station transmission beam for the PDCCH in step S304, or may assume the same (fig. 7 shows an example that is not assumed).

The UE may assume that the base station reception beam of the PUCCH in step S306 is the same as the base station transmission beam of the PDCCH in step S304.

The UE may assume that the UE transmission beam of the PUCCH in step S306 is the same as the UE reception beam of the PDCCH in step S304.

Furthermore, when the TCI state is not set for the PDCCH, the UE may assume that the UE transmission beam of the PUCCH in step S306, the UE reception beam of the PDCCH in step S304, and the UE reception beam corresponding to the latest beam measurement result reported in step S302 (the UE reception beam used in step S301) are the same.

According to the above-described embodiment, the TCI state for the PDCCH can be set more flexibly.

< modification example >

[ variation of PDCCH reception processing ]

In the assumption described above regarding the PDCCH reception process, "the latest beam measurement result to be reported" may not be limited to a specific type of CSI report. The specific kind of CSI report may also be, for example, one of a Periodic CSI (P-CSI: Periodic CSI) report, an Aperiodic CSI (a-CSI: Aperiodic CSI) report, a Semi-permanent (Semi-Persistent) CSI (SP-CSI: Semi-Persistent CSI) report, or a combination thereof.

In this case, the base station controls the UE to perform a specific type of CSI report, thereby changing the assumption of the UE regarding the PDCCH reception beam (TCI state).

In addition, the "reception beam/base station transmission beam/TCI state for PDCCH" in the above assumption may be the "reception beam/base station transmission beam/TCI state for PDCCH at time T", and in this case, the "latest report" in the above assumption may be replaced with "at time T compared to time T_offsetThe most recent time reported beforeNew ". T is_offsetOr may be defined based on the time required for the UE or the base station to switch beams (e.g., UE receive beams, base station transmit beams).

In addition, with T_offsetThe related information may also be notified to the UE using higher layer signaling, physical layer signaling, or a combination thereof.

FIG. 8 is a graph showing a graph based on T_offsetFig. is a diagram of an example of an assumption of a base station transmission beam of the PDCCH. Steps S302-1 and S302-2 are similar to step S302 described above, but differ in that S302-1 is a report on the base station transmission beam #1 and S302-2 is a report on the base station transmission beam # 2.

Steps S304-1 and S304-2 are similar to step S304 described above, but differ in that the UE assumes that the base station transmission beam #1 is applied to the PDCCH in S304-1, and the UE assumes that the base station transmission beam #2 is applied to the PDCCH in S304-2.

This is because at the time of step S304-1, the report of step S304-1 is at T_offsetThe latest report transmitted at the previous time point, but the report of step S304-2 is at T_offsetAre transmitted at a time within.

Further, this is because at the time of step S304-2, the report of step S304-2 is at T_offsetThe latest report transmitted at the previous time.

Also, the assumption of the UE regarding the reception beam for the PDCCH may vary within the duration (duration) of a certain CORESET.

FIG. 9 is a graph showing a graph based on T_offsetFig. is a diagram of another example of the base station transmission beam of the PDCCH. In this example, step S302-3 is shown at a different location in the time of CORESET as compared to FIG. 8.

Further, compared to step S304 described above, the UE is different in that the UE assumes that the base station transmission beam #1 is applied to the PDCCH up to the middle in the CORESET of step S304-3, and the UE assumes that the base station transmission beam #2 is applied to the subsequent PDCCH.

This is because the report of step S304-1 is at T at the time point halfway in CORESET described above_offsetTransmitted at the previous timeBut the report of step S304-2 is at T_offsetAre transmitted at a time within.

This is because the report of step S304-2 is at T after the time point in the middle of CORESET described above_offsetThe latest report transmitted at the previous time.

FIG. 10 is a graph showing a graph based on T_offsetFig. of yet another example of the base station transmission beam of the PDCCH in (1). In this example, the same example as fig. 9 is shown.

Fig. 10 is different from fig. 9 in that the UE does not change the assumption of the base station transmission beam in the CORESET in step S304-3 in the middle. The UE may also assume that the base station transmission beam applied to the PDCCH in the CORESET is T from the time of the starting position (e.g., starting symbol, starting slot, etc.) of the CORESET_offsetThe base station corresponding to the latest report transmitted at the previous time, i.e., the report of step S304-1, transmits the beam # 1.

In this way, the UE can also assume T from the reporting of the beam measurement result_offsetThe base station transmission beam/UE reception beam of the CORESET (PDCCH included in the CORESET) started later is assumed to be the same as the base station transmission beam/UE reception beam corresponding to the beam measurement result. In this case, since switching of the base station transmission beam or the UE reception beam does not occur in CORESET, it is possible to suppress occurrence of a time (time at which transmission and reception are not possible) for switching of the transmission and reception beams in CORESET.

[ other T_offset]

When the low delay beam selection is set by the higher layer signaling, the UE may assume that the base station transmission beam of the PDSCH at time T is T compared with time T_offset2The base station transmission beam of the (latest) PDCCH at the previous time is the same.

When the low delay beam selection is set by the higher layer signaling, the UE may assume that the UE reception beam of the PDSCH at time T is T compared with time T_offset2The UE reception beam of the (latest) PDCCH at the previous time is the same.

UE passes higher layer signaling at low delay beam selectionWhen the command is set, the base station reception beam of the PUCCH at time T may be assumed to be T compared with time T_offset3At least one of the base station transmission beam of the PDSCH (the latest) and the base station transmission beam of the PDCCH at the previous time is the same.

When the low-delay beam selection is set by the higher layer signaling, the UE may assume that the UE transmission beam of the PUCCH at time T is T compared with T at time T_offset3At least one of the UE reception beam of the PDSCH (the latest) and the UE reception beam of the PDCCH at the previous time is the same.

T_offset2、T_offset3Etc. may also be defined based on the time required for the UE or base station to switch beams (e.g., UE transmit beam, base station receive beam). In addition, with T_offset2、T_offset3Etc. the related information may also be notified to the UE using higher layer signaling, physical layer signaling, or a combination thereof.

In addition, "assuming (estimate)" in the present disclosure can also be assumed to mean performing reception processing, transmission processing, measurement processing, and the like.

(Wireless communication System)

Hereinafter, a configuration of a radio communication system according to an embodiment of the present disclosure will be described. In this radio communication system, communication is performed using one of the radio communication methods according to the above embodiments of the present disclosure or a combination thereof.

Fig. 11 is a diagram showing an example of a schematic configuration of a radio communication system according to an embodiment. In the wireless communication system 1, Carrier Aggregation (CA) and/or Dual Connectivity (DC) can be applied in which a plurality of basic frequency blocks (component carriers) are integrated into one unit of 1 system bandwidth (e.g., 20MHz) of the LTE system.

The wireless communication system 1 may be referred to as LTE (Long Term Evolution), LTE-a (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), NR (New Radio), FRA (Future Radio Access), New-RAT (Radio Access Technology), and the like, and may also be referred to as a system that implements them.

The wireless communication system 1 includes a base station 11 forming a macrocell C1 having a relatively wide coverage area, and base stations 12(12a to 12C) arranged within the macrocell C1 and forming a small cell C2 narrower than the macrocell C1. In addition, the user terminal 20 is arranged in the macro cell C1 and each small cell C2. The arrangement, number, and the like of each cell and user terminal 20 are not limited to the illustrated embodiments.

User terminal 20 can connect to both base station 11 and base station 12. The user terminal 20 envisages the use of either CA or DC while using macro cell C1 and small cell C2. Further, the user terminal 20 may also apply CA or DC using a plurality of cells (CCs).

The user terminal 20 and the base station 11 can communicate with each other using a carrier having a narrow bandwidth (also referred to as an existing carrier, legacy carrier, or the like) in a relatively low frequency band (e.g., 2 GHz). On the other hand, a carrier having a relatively high bandwidth (e.g., 3.5GHz, 5GHz, etc.) may be used between the user terminal 20 and the base station 12, or the same carrier as that used between the user terminal and the base station 11 may be used. The configuration of the frequency band used by each base station is not limited to this.

The user terminal 20 can perform communication in each cell by using Time Division Duplex (TDD) and/or Frequency Division Duplex (FDD). In addition, a single parameter set (Numerology) may be applied to each cell (carrier), or a plurality of different parameter sets may be applied.

The parameter set may be a communication parameter applied to transmission and/or reception of a certain signal and/or channel, and may indicate at least one of a subcarrier interval, a bandwidth, a symbol length, a cyclic prefix length, a subframe length, a TTI length, the number of symbols per TTI, a radio frame structure, a specific filtering process performed by the transmitter and receiver in a frequency domain, a specific windowing process performed by the transmitter and receiver in a time domain, and the like. For example, when the subcarrier spacing of the configured OFDM symbols differs and/or the number of OFDM symbols differs for a certain physical channel, it may be said that the parameter set differs.

The connection between the base station 11 and the base station 12 (or between two base stations 12) may be wired (for example, an optical fiber conforming to a CPRI (Common Public Radio Interface), an X2 Interface, or the like) or wireless.

The base station 11 and each base station 12 are connected to the upper station apparatus 30, and are connected to the core network 40 via the upper station apparatus 30. The upper node apparatus 30 includes, for example, an access gateway apparatus, a Radio Network Controller (RNC), a Mobility Management Entity (MME), and the like, but is not limited thereto. Each base station 12 may be connected to the upper station apparatus 30 via the base station 11.

The base station 11 is a base station having a relatively wide coverage area, and may be referred to as a macro base station, a sink node, an enb (enodeb), a transmission/reception point, or the like. The base station 12 is a base station having a local coverage area, and may be referred to as a small base station, a micro base station, a pico base station, a femto base station, an HeNB (home evolved node b), an RRH (Remote Radio Head), a transmission/reception point, or the like. Hereinafter, the base stations 11 and 12 are collectively referred to as the base station 10 without distinguishing them.

Each user terminal 20 is a terminal supporting various communication schemes such as LTE and LTE-a, and may include not only a mobile communication terminal (mobile station) but also a fixed communication terminal (fixed station).

In the wireless communication system 1, as a radio Access scheme, Orthogonal Frequency Division Multiple Access (OFDMA) is applied to a downlink, and Single Carrier Frequency Division Multiple Access (SC-FDMA) and/or OFDMA is applied to an uplink.

OFDMA is a multicarrier transmission scheme in which a frequency band is divided into a plurality of narrow frequency bands (subcarriers) and data is mapped to each subcarrier to perform communication. SC-FDMA is a single-carrier transmission scheme in which a system bandwidth is divided into bands each composed of one or consecutive resource blocks for each terminal, and a plurality of terminals use different bands to reduce interference between terminals. The uplink and downlink radio access schemes are not limited to the combination thereof, and other radio access schemes may be used.

In the radio communication system 1, as Downlink channels, Downlink Shared channels (PDSCH: Physical Downlink Shared Channel), Broadcast channels (PBCH: Physical Broadcast Channel), Downlink L1/L2 control channels, and the like, which are Shared by the user terminals 20, are used. User data, higher layer control Information, SIB (System Information Block), and the like are transmitted through the PDSCH. Also, MIB (Master Information Block) is transmitted through PBCH.

The Downlink L1/L2 Control Channel includes PDCCH (Physical Downlink Control Channel), EPDCCH (Enhanced Physical Downlink Control Channel), PCFICH (Physical Control Format Indicator Channel), PHICH (Physical Hybrid-ARQ Indicator Channel), and the like. Downlink Control Information (DCI) including scheduling Information of the PDSCH and/or the PUSCH and the like are transmitted through the PDCCH.

In addition, DCI scheduling DL data reception may be referred to as DL allocation, and DCI scheduling UL data transmission may be referred to as UL grant.

The number of OFDM symbols for PDCCH is transmitted through PCFICH. Transmission acknowledgement information (for example, also referred to as retransmission control information, HARQ-ACK, ACK/NACK, and the like) of HARQ (Hybrid Automatic Repeat reQuest) for PUSCH is transmitted by PHICH. EPDCCH and PDSCH (downlink shared data channel) are frequency division multiplexed, and used for transmission of DCI and the like in the same manner as PDCCH.

In the radio communication system 1, as Uplink channels, an Uplink Shared Channel (PUSCH), an Uplink Control Channel (PUCCH), a Random Access Channel (PRACH), and the like, which are Shared by the user terminals 20, are used. Through the PUSCH, user data, higher layer control information, and the like are transmitted. In addition, downlink radio Quality information (Channel Quality Indicator (CQI)), acknowledgement information, Scheduling Request (SR), and the like are transmitted through the PUCCH. Through the PRACH, a random access preamble for establishing a connection with a cell is transmitted.

In the wireless communication system 1, as downlink Reference signals, Cell-specific Reference signals (CRS), Channel State Information Reference signals (CSI-RS), DeModulation Reference signals (DMRS), Positioning Reference Signals (PRS), and the like are transmitted. In addition, in the wireless communication system 1, as the uplink Reference Signal, a measurement Reference Signal (SRS: Sounding Reference Signal), a demodulation Reference Signal (DMRS), and the like are transmitted. In addition, the DMRS may also be referred to as a user terminal specific Reference Signal (UE-specific Reference Signal). Further, the reference signals transmitted are not limited to these.

(base station)

Fig. 12 is a diagram showing an example of the overall configuration of a base station according to an embodiment. The base station 10 includes a plurality of transmission/reception antennas 101, an amplifier unit 102, a transmission/reception unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission line interface 106. The number of the transmission/reception antenna 101, the amplifier unit 102, and the transmission/reception unit 103 may be one or more.

User data transmitted from the base station 10 to the user terminal 20 via the downlink is input from the upper station apparatus 30 to the baseband signal processing unit 104 via the transmission line interface 106.

In baseband signal processing section 104, with respect to user Data, transmission processes such as PDCP (Packet Data Convergence Protocol) layer processing, division and combination of user Data, RLC (Radio Link Control) layer transmission processing such as RLC retransmission Control, MAC (Medium Access Control) retransmission Control (for example, HARQ transmission processing), scheduling, transport format selection, channel coding, Inverse Fast Fourier Transform (IFFT) processing, and precoding processing are performed, and the user Data is transferred to transmission/reception section 103. The downlink control signal is also subjected to transmission processing such as channel coding and inverse fast fourier transform, and transferred to transmission/reception section 103.

Transmission/reception section 103 converts the baseband signal output from baseband signal processing section 104 by precoding for each antenna to the radio frequency band and transmits the converted signal. The radio frequency signal frequency-converted by the transmission/reception section 103 is amplified by the amplifier section 102 and transmitted from the transmission/reception antenna 101. The transmitting/receiving section 103 can be configured by a transmitter/receiver, a transmitting/receiving circuit, or a transmitting/receiving device described based on common knowledge in the technical field of the present disclosure. The transmission/reception section 103 may be configured as an integrated transmission/reception section, or may be configured by a transmission section and a reception section.

On the other hand, for the uplink signal, the radio frequency signal received by the transmission/reception antenna 101 is amplified by the amplifier unit 102. Transmission/reception section 103 receives the uplink signal amplified by amplifier section 102. Transmitting/receiving section 103 frequency-converts the received signal into a baseband signal, and outputs the baseband signal to baseband signal processing section 104.

The baseband signal processing section 104 performs Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing, error correction decoding, reception processing for MAC retransmission control, and reception processing for the RLC layer and the PDCP layer on the user data included in the input uplink signal, and transfers the user data to the upper station apparatus 30 via the transmission path interface 106. The call processing unit 105 performs call processing (setting, release, and the like) of a communication channel, state management of the base station 10, management of radio resources, and the like.

The transmission line interface 106 transmits and receives signals to and from the upper station apparatus 30 via a specific interface. The transmission path Interface 106 may transmit and receive signals (backhaul link signaling) with other base stations 10 via an inter-base station Interface (e.g., an optical fiber compliant with a Common Public Radio Interface (CPRI), an X2 Interface).

Further, transmission/reception section 103 may further include an analog beamforming section for performing analog beamforming. The analog beamforming unit may be configured by an analog beamforming circuit (e.g., a phase shifter or a phase shift circuit) or an analog beamforming device (e.g., a phase shifter) described based on common knowledge in the technical field of the present invention. The transmission/reception antenna 101 may be formed of an array antenna, for example.

Fig. 13 is a diagram showing an example of a functional configuration of a base station according to an embodiment. In this example, the functional blocks of the characteristic parts in the present embodiment are mainly shown, and it is also conceivable that the base station 10 further has other functional blocks necessary for wireless communication.

The baseband signal processing section 104 includes at least a control section (scheduler) 301, a transmission signal generation section 302, a mapping section 303, a reception signal processing section 304, and a measurement section 305. These configurations may be included in base station 10, and a part or all of the configurations may not be included in baseband signal processing section 104.

The control unit (scheduler) 301 performs overall control of the base station 10. The control unit 301 may be configured by a controller, a control circuit, or a control device described based on common knowledge in the technical field of the present disclosure.

The control unit 301 controls, for example, generation of a signal in the transmission signal generation unit 302, allocation of a signal in the mapping unit 303, and the like. Further, the control unit 301 controls reception processing of signals in the received signal processing unit 304, measurement of signals in the measurement unit 305, and the like.

Control section 301 controls scheduling (e.g., resource allocation) of system information, a downlink data signal (e.g., a signal transmitted via PDSCH), and a downlink control signal (e.g., a signal transmitted via PDCCH and/or EPDCCH. Control section 301 controls generation of a downlink control signal and/or a downlink data signal and the like based on the result of determining whether retransmission control for an uplink data signal is necessary or not and the like.

Control section 301 controls scheduling of Synchronization signals (e.g., PSS (Primary Synchronization Signal))/SSS (Secondary Synchronization Signal))), downlink reference signals (e.g., CRS, CSI-RS, DMRS), and the like.

Control section 301 controls scheduling of an uplink data signal (e.g., a signal transmitted on a PUSCH), an uplink control signal (e.g., a signal transmitted on a PUCCH and/or a PUSCH, acknowledgement information, etc.), a random access preamble (e.g., a signal transmitted on a PRACH), an uplink reference signal, and the like.

Control section 301 may also perform control for forming a transmission beam and/or a reception beam using digital BF (e.g., precoding) in baseband signal processing section 104 and/or analog BF (e.g., phase rotation) in transmission/reception section 103. Control section 301 may perform control for forming a beam based on the downlink propagation path information, uplink propagation path information, and the like. These propagation path information may be acquired from received signal processing section 304 and/or measurement section 305.

Transmission signal generating section 302 generates a downlink signal (downlink control signal, downlink data signal, downlink reference signal, and the like) based on an instruction from control section 301, and outputs the downlink signal to mapping section 303. The transmission signal generation unit 302 can be configured by a signal generator, a signal generation circuit, or a signal generation device described based on common knowledge in the technical field of the present disclosure.

Transmission signal generating section 302 generates, for example, a DL assignment notifying assignment information of downlink data and/or an UL grant notifying assignment information of uplink data, based on an instruction from control section 301. Both DL allocation and UL grant are DCI, and comply with DCI format. The downlink data signal is subjected to coding processing and modulation processing according to a coding rate, a modulation scheme, and the like determined based on Channel State Information (CSI) and the like from each user terminal 20.

Mapping section 303 maps the downlink signal generated by transmission signal generating section 302 to a specific radio resource based on an instruction from control section 301, and outputs the result to transmitting/receiving section 103. The mapping unit 303 can be configured by a mapper, a mapping circuit, or a mapping device described based on common knowledge in the technical field related to the present disclosure.

Received signal processing section 304 performs reception processing (for example, demapping, demodulation, decoding, and the like) on the received signal input from transmission/reception section 103. Here, the reception signal is, for example, an uplink signal (an uplink control signal, an uplink data signal, an uplink reference signal, or the like) transmitted from the user terminal 20. The reception signal processing unit 304 can be configured by a signal processor, a signal processing circuit, or a signal processing device described based on common knowledge in the technical field of the present disclosure.

The received signal processing unit 304 outputs information decoded by the reception processing to the control unit 301. For example, when a PUCCH including HARQ-ACK is received, the HARQ-ACK is output to control section 301. Further, the received signal processing unit 304 outputs the received signal and/or the signal after the reception processing to the measurement unit 305.

The measurement unit 305 performs measurements related to the received signal. The measurement unit 305 can be configured by a measurement instrument, a measurement circuit, or a measurement device described based on common knowledge in the technical field of the present disclosure.

For example, measurement section 305 may perform RRM (Radio Resource Management) measurement, CSI (Channel State Information) measurement, and the like based on the received signal. Measurement section 305 may also perform measurement of Received Power (for example, RSRP (Reference Signal Received Power)), Received Quality (for example, RSRQ (Reference Signal Received Quality)), SINR (Signal to Interference plus Noise Ratio)), SNR (Signal to Noise Ratio)), Signal Strength (for example, RSSI (Received Signal Strength Indicator)), propagation path information (for example, CSI), and the like. The measurement result may also be output to the control unit 301.

Transmission/reception section 103 may transmit Downlink Control Information (DCI) (DL assignment, etc.) for scheduling of a downlink shared channel (e.g., PDSCH) using the PDCCH. The transmission/reception section 103 may transmit the setting information of the low delay beam selection to the user terminal 20.

Transmission/reception section 103 may receive, from user terminal 20, a measurement result of a reference signal (reference signal for CSI measurement, for example, SSB, CSI-RS) measured by applying the downlink spatial domain reception filter.

The control unit 301 may also perform the following control: for the user terminal 20 in which the low-delay beam selection is set by the higher layer signaling, the same spatial filter is used for transmission of the PDCCH and transmission/reception of the specific channel.

The control unit 301 may also perform the following control: the same downlink spatial domain transmission filter is used for transmission of the PDCCH and transmission of the PDSCH.

The control unit 301 may also perform the following control: the same spatial domain transmission filter is used for transmission of the PDCCH and reception of the PUCCH.

Further, the control unit 301 may also perform the following control: for the user terminal 20 for which the low-delay beam selection is set by the higher layer signaling, the PDCCH is transmitted using the same downlink spatial domain transmission filter as the downlink spatial domain transmission filter corresponding to the latest received measurement result (CSI measurement result or the like).

The control unit 301 may also perform the following control: the PDSCH is transmitted using the same downlink spatial domain transmission filter as used for the transmission of the PDCCH.

The control unit 301 may also perform the following control: the PUCCH is received using the same uplink spatial domain reception filter as the downlink spatial domain transmission filter used for transmission of the PDCCH.

(user terminal)

Fig. 14 is a diagram showing an example of the overall configuration of a user terminal according to an embodiment. The user terminal 20 includes a plurality of transmission/reception antennas 201, an amplifier unit 202, a transmission/reception unit 203, a baseband signal processing unit 204, and an application unit 205. The number of the transmission/reception antenna 201, the amplifier unit 202, and the transmission/reception unit 203 may be one or more.

The radio frequency signal received by the transmission and reception antenna 201 is amplified by the amplifier unit 202. Transmission/reception section 203 receives the downlink signal amplified by amplifier section 202. Transmitting/receiving section 203 frequency-converts the received signal into a baseband signal, and outputs the baseband signal to baseband signal processing section 204. The transmitting/receiving section 203 can be configured by a transmitter/receiver, a transmitting/receiving circuit, or a transmitting/receiving device described based on common knowledge in the technical field of the present disclosure. The transmission/reception unit 203 may be configured as an integrated transmission/reception unit, or may be configured by a transmission unit and a reception unit.

Baseband signal processing section 204 performs FFT processing, error correction decoding, reception processing of retransmission control, and the like on the input baseband signal. The downlink user data is forwarded to the application unit 205. The application section 205 performs processing and the like relating to layers higher than the physical layer and the MAC layer. Furthermore, the broadcast information among the data, which may also be downlink, is also forwarded to the application unit 205.

On the other hand, uplink user data is input from the application section 205 to the baseband signal processing section 204. Baseband signal processing section 204 performs transmission processing for retransmission control (e.g., transmission processing for HARQ), channel coding, precoding, Discrete Fourier Transform (DFT) processing, IFFT processing, and the like, and transfers the result to transmitting/receiving section 203.

Transmission/reception section 203 converts the baseband signal output from baseband signal processing section 204 into a radio frequency band and transmits the radio frequency band. The radio frequency signal frequency-converted by the transmission/reception section 203 is amplified by the amplifier section 202 and transmitted from the transmission/reception antenna 201.

Further, transmission/reception section 203 may further include an analog beamforming section for performing analog beamforming. The analog beamforming unit may be configured by an analog beamforming circuit (e.g., a phase shifter or a phase shift circuit) or an analog beamforming device (e.g., a phase shifter) described based on common knowledge in the technical field of the present invention. The transmission/reception antenna 201 may be formed of an array antenna, for example.

Fig. 15 is a diagram showing an example of a functional configuration of a user terminal according to an embodiment. In this example, the functional blocks mainly representing the characteristic parts in the present embodiment are assumed to be provided in addition to other functional blocks necessary for wireless communication in the user terminal 20.

The baseband signal processing section 204 included in the user terminal 20 includes at least a control section 401, a transmission signal generation section 402, a mapping section 403, a received signal processing section 404, and a measurement section 405. These components may be included in the user terminal 20, or a part or all of the components may not be included in the baseband signal processing section 204.

The control unit 401 performs overall control of the user terminal 20. The control unit 401 can be configured by a controller, a control circuit, or a control device described based on common knowledge in the technical field of the present disclosure.

Control section 401 controls generation of a signal in transmission signal generation section 402, allocation of a signal in mapping section 403, and the like, for example. Further, the control unit 401 controls reception processing of signals in the received signal processing unit 404, measurement of signals in the measurement unit 405, and the like.

Control section 401 acquires the downlink control signal and the downlink data signal transmitted from base station 10 from received signal processing section 404. Control section 401 controls generation of an uplink control signal and/or an uplink data signal based on a downlink control signal and/or a result of determination of necessity or unnecessity of retransmission control for a downlink data signal.

Control section 401 may also perform control for forming a transmission beam and/or a reception beam using digital BF (e.g., precoding) in baseband signal processing section 204 and/or analog BF (e.g., phase rotation) in transmission/reception section 203. Control section 401 may perform control for forming a beam based on downlink propagation path information, uplink propagation path information, and the like. These propagation path information may be acquired from the received signal processing unit 404 and/or the measurement unit 405.

When various information notified from base station 10 is acquired from received signal processing section 404, control section 401 may update parameters for control based on the information.

Transmission signal generating section 402 generates an uplink signal (uplink control signal, uplink data signal, uplink reference signal, and the like) based on an instruction from control section 401, and outputs the uplink signal to mapping section 403. The transmission signal generation unit 402 can be configured by a signal generator, a signal generation circuit, or a signal generation device described based on common knowledge in the technical field of the present disclosure.

Transmission signal generating section 402 generates an uplink control signal related to transmission acknowledgement information, Channel State Information (CSI), and the like, for example, based on an instruction from control section 401. Transmission signal generation section 402 also generates an uplink data signal based on an instruction from control section 401. For example, when the UL grant is included in the downlink control signal notified from base station 10, transmission signal generating section 402 is instructed from control section 401 to generate the uplink data signal.

Mapping section 403 maps the uplink signal generated by transmission signal generating section 402 to a radio resource based on an instruction from control section 401, and outputs the result to transmitting/receiving section 203. The mapping unit 403 can be configured by a mapper, a mapping circuit, or a mapping device described based on common knowledge in the technical field related to the present disclosure.

Received signal processing section 404 performs reception processing (for example, demapping, demodulation, decoding, and the like) on the received signal input from transmission/reception section 203. Here, the reception signal is, for example, a downlink signal (downlink control signal, downlink data signal, downlink reference signal, etc.) transmitted from the base station 10. The reception signal processing unit 404 can be configured by a signal processor, a signal processing circuit, or a signal processing device described based on common knowledge in the technical field of the present disclosure. Further, the received signal processing unit 404 can constitute a receiving unit according to the present disclosure.

The received signal processing unit 404 outputs information decoded by the reception processing to the control unit 401. Received signal processing section 404 outputs, for example, broadcast information, system information, RRC signaling, DCI, and the like to control section 401. Further, the received signal processing unit 404 outputs the received signal and/or the signal after the reception processing to the measurement unit 405.

The measurement unit 405 performs measurements related to the received signal. For example, measurement section 405 may perform intra-frequency measurement and/or inter-frequency measurement on one or both of the first carrier and the second carrier. When the serving cell is included in the first carrier, measurement section 405 may perform inter-frequency measurement in the second carrier based on the measurement instruction acquired from received signal processing section 404. The measurement unit 405 can be configured by a measurement instrument, a measurement circuit, or a measurement device described based on common knowledge in the technical field of the present disclosure.

For example, measurement section 405 may perform RRM measurement, CSI measurement, and the like based on the received signal. Measurement unit 405 may also measure for received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), and so on. The measurement result may also be output to the control unit 401.

Transmission/reception section 203 may receive a PDCCH including Downlink Control Information (DCI) (DL assignment, etc.) used for scheduling of a downlink shared channel (e.g., PDSCH). Transmission/reception section 203 may receive setting information for low-delay beam selection from base station 10.

Transmission/reception section 203 may transmit the measurement result of the reference signal (reference signal for CSI measurement, for example, SSB, CSI-RS) measured by applying the downlink spatial domain reception filter to base station 10.

When the low delay beam selection is set by the higher layer signaling, control section 401 may assume that the same spatial filter is used for transmission of the PDCCH in base station 10 and transmission/reception of a specific channel (at least one of transmission and reception) in base station 10.

Control section 401 may assume that the same downlink spatial domain transmission filter is used for transmission of PDCCH in base station 10 and transmission of PDSCH in base station 10.

Control section 401 may assume that a downlink spatial domain transmission filter used for transmission of a PDCCH in base station 10 is the same as an uplink spatial domain reception filter used for reception of a PUCCH in base station 10.

When the low delay beam selection is set by the higher layer signaling, control section 401 may assume that the downlink spatial domain reception filter of user terminal 20 used for receiving the PDCCH is the same as the downlink spatial domain reception filter of user terminal 20 corresponding to the latest measurement result (CSI measurement result or the like) transmitted.

Control section 401 may assume that the downlink spatial domain reception filter of user terminal 20 used for receiving PDSCH is the same as the downlink spatial domain reception filter of user terminal 20 used for receiving PDCCH.

Control section 401 may assume that the uplink spatial domain transmission filter of user terminal 20 used for transmission of the PUCCH is the same as the downlink spatial domain reception filter of user terminal 20 used for reception of the PDCCH.

(hardware construction)

The block diagrams used in the description of the above embodiments represent blocks in functional units. These functional blocks (structural units) are realized by any combination of at least one of hardware and software. Note that the method of implementing each functional block is not particularly limited. That is, each functional block may be implemented by one physically or logically combined device, or may be implemented by connecting two or more physically or logically separated devices directly or indirectly (for example, by wire or wireless) and using these multiple devices.

For example, the base station, the user terminal, and the like in one embodiment of the present disclosure may also function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 16 is a diagram showing an example of hardware configurations of a base station and a user terminal according to an embodiment. The base station 10 and the user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In the following description, the language "means" may be replaced with a circuit, a device, a unit, or the like. The hardware configuration of the base station 10 and the user terminal 20 may include one or more of the illustrated devices, or may not include some of the devices.

For example, only one processor 1001 is illustrated, but there may be multiple processors. The processing may be executed by 1 processor, or the processing may be executed by 2 or more processors simultaneously, sequentially, or by another method. The processor 1001 may be mounted on 1 or more chips.

Each function in the base station 10 and the user terminal 20 is realized by, for example, causing specific software (program) to be read into hardware such as the processor 1001 and the memory 1002, causing the processor 1001 to perform an operation to control communication via the communication device 1004, or to control at least one of reading and writing of data in the memory 1002 and the storage 1003.

The processor 1001 controls the entire computer by operating an operating system, for example. The processor 1001 may be configured by a Central Processing Unit (CPU) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like. For example, the baseband signal processing unit 104(204), the call processing unit 105, and the like may be implemented by the processor 1001.

The processor 1001 reads out a program (program code), a software module, data, and the like from at least one of the memory 1003 and the communication device 1004 to the memory 1002, and executes various processes in accordance with the read program (program code), software module, data, and the like. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiments is used. For example, the control unit 401 of the user terminal 20 may be realized by a control program stored in the memory 1002 and operated by the processor 1001, and may be similarly realized for other functional blocks.

The Memory 1002 is a computer-readable recording medium, and may be configured by at least one of ROM (Read Only Memory), EPROM (erasable Programmable ROM), EEPROM (electrically EPROM), RAM (Random Access Memory), and other suitable storage media. The memory 1002 may also be referred to as a register, cache, main memory (primary storage), or the like. The memory 1002 can store a program (program code), a software module, and the like that are executable to implement the wireless communication method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, and may be configured by at least one of a Floppy disk, a Floppy (registered trademark) disk, a magneto-optical disk (e.g., a compact Disc (CD-rom), a digital versatile Disc, a Blu-ray (registered trademark) disk), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, and other appropriate storage media. The storage 1003 may also be referred to as a secondary storage device.

The communication device 1004 is hardware (transmission/reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, or the like. Communication apparatus 1004 may include a high-Frequency switch, a duplexer, a filter, a Frequency synthesizer, and the like, for example, in order to realize at least one of Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD). For example, the transmission/reception antennas 101 and 201, the amplifier units 102 and 202, the transmission/reception units 103 and 203, the transmission line interface 106, and the like described above may be realized by the communication device 1004.

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, and the like) that receives an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED (Light Emitting Diode) lamp, or the like) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated (for example, a touch panel).

Further, the processor 1001, the memory 1002, and other devices are connected by a bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using different buses between the respective devices.

The base station 10 and the user terminal 20 may include hardware such as a microprocessor, a Digital Signal Processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), and the like, and a part or all of the functional blocks may be implemented using the hardware. For example, the processor 1001 may also be installed using at least one of these hardware.

(modification example)

In addition, terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and the symbol may be a signal (signaling). Further, the signal may also be a message. The reference signal may be also referred to as rs (reference signal) or may be referred to as Pilot (Pilot), Pilot signal, or the like according to the applied standard. Further, a Component Carrier (CC) may also be referred to as a cell, a frequency Carrier, a Carrier frequency, and the like.

A radio frame may also be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting the radio frame may also be referred to as a subframe. Further, the subframe may be configured by one or more slots in the time domain. The sub-frame may also be a fixed length of time (e.g., 1ms) independent of the parameter set.

Here, the parameter set may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. The parameter set may indicate at least one of a SubCarrier Spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a Transmission Time Interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by the transmitter/receiver in the frequency domain, a specific windowing process performed by the transmitter/receiver in the Time domain, and the like.

The slot may be formed of one or more symbols in the time domain (OFDM (Orthogonal Frequency Division Multiplexing) symbol, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbol, or the like). Further, the time slot may also be a time unit based on a parameter set.

A timeslot may also contain multiple mini-slots. Each mini-slot may also be made up of one or more symbols in the time domain. In addition, a mini-slot may also be referred to as a sub-slot. A mini-slot may also be made up of a smaller number of symbols than a slot. PDSCH (or PUSCH) transmitted in a time unit larger than a mini slot may also be referred to as PDSCH (PUSCH) mapping type a. PDSCH (or PUSCH) transmitted using mini-slots may also be referred to as PDSCH (PUSCH) mapping type B.

The radio frame, subframe, slot, mini-slot, and symbol all represent a unit of time when a signal is transmitted. The radio frame, subframe, slot, mini-slot, and symbol may be referred to by other names corresponding thereto. In addition, time units such as frames, subframes, slots, mini-slots, symbols, etc. in the present disclosure may be replaced with each other.

For example, 1 subframe may also be referred to as a Transmission Time Interval (TTI), a plurality of consecutive subframes may also be referred to as TTIs, and 1 slot or 1 mini-slot may also be referred to as TTIs. That is, at least one of the subframe and TTI may be a subframe (1ms) in the conventional LTE, may be a period shorter than 1ms (for example, 1 to 13 symbols), or may be a period longer than 1 ms. The unit indicating TTI may be referred to as a slot, a mini slot, or the like, and is not referred to as a subframe.

Here, the TTI refers to, for example, the minimum time unit of scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling for allocating radio resources (frequency bandwidths, transmission powers, and the like that can be used by each user terminal) to each user terminal in units of TTIs. In addition, the definition of TTI is not limited thereto.

The TTI may be a transmission time unit of a channel-coded data packet (transport block), code block, code word, or the like, or may be a processing unit of scheduling, link adaptation, or the like. In addition, when a TTI is given, a time interval (for example, the number of symbols) to which a transport block, a code block, a codeword, and the like are actually mapped may be shorter than the TTI.

In addition, when 1 slot or 1 mini-slot is referred to as TTI, 1TTI or more (i.e., 1 slot or more or 1 mini-slot) may be the minimum time unit for scheduling. The number of slots (the number of mini-slots) constituting the minimum time unit of the schedule may be controlled.

The TTI having a time length of 1ms may also be referred to as a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may also be referred to as a shortened TTI, a short TTI, a partial TTI, a shortened subframe, a short subframe, a mini-slot, a sub-slot, a slot, etc.

In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be replaced with a TTI having a time length exceeding 1ms, and a short TTI (e.g., a shortened TTI, etc.) may be replaced with a TTI having a TTI length smaller than the long TTI and equal to or longer than 1 ms.

A Resource Block (RB) is a Resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers (subcarriers) in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the parameter set, and may be 12, for example. The number of subcarriers included in the RB may also be decided based on the parameter set.

The RB may include one or more symbols in the time domain, and may have a length of 1 slot, 1 mini-slot, 1 subframe, or 1 TTI. The 1TTI, 1 subframe, and the like may be configured by one or more resource blocks.

In addition, one or more RBs may also be referred to as Physical Resource Blocks (PRBs), Sub-Carrier groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB peers, and so on.

In addition, a Resource block may also be composed of one or more Resource Elements (REs). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

The Bandwidth Part (BWP: Bandwidth Part) (which may also be referred to as a partial Bandwidth) may also indicate a subset of consecutive common RBs (common resource blocks) for a certain parameter set in a certain carrier. Here, the common RB may also be determined by an index of an RB with reference to a common reference point of the carrier. PRBs may also be defined in a certain BWP, and are assigned sequence numbers within the BWP.

The BWP may include UL BWP (UL BWP) and DL BWP (DL BWP). One or more BWPs may also be set within 1 carrier for the UE.

At least one of the provisioned BWPs may be active, and the UE may not be supposed to transmit or receive a specific signal/channel outside the active BWP. In addition, "cell", "carrier", and the like in the present disclosure may also be replaced with "BWP".

The above-described structures of radio frames, subframes, slots, mini slots, symbols, and the like are merely examples. For example, the number of subframes included in the radio frame, the number of slots per subframe or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the Cyclic Prefix (CP) length, and other configurations may be variously changed.

In addition, information, parameters, and the like described in the present disclosure may be expressed by absolute values, relative values to specific values, or other corresponding information. For example, the radio resource may also be indicated by a specific index.

The names used for parameters and the like in the present disclosure are not limitative names in any point. Further, the equations and the like using these parameters may be different from those explicitly disclosed in the present disclosure. Since various channels (PUCCH (Physical Uplink Control Channel), PDCCH (Physical Downlink Control Channel), and the like) and information elements can be identified by an appropriate name, the names assigned to these various channels and information elements are not limitative names at all points.

Information, signals, and the like described in this disclosure may also be represented using one of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, and the like that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or photons, or any combination thereof.

Information, signals, and the like can be output from at least one of an upper layer (upper layer) to a lower layer (lower layer) and from the lower layer to the upper layer. Information, signals, and the like may also be input and output via a plurality of network nodes.

The information, signals, and the like that are input/output may be stored in a specific place (for example, a memory) or may be managed using a management table. The information, signals, and the like to be input and output can be overwritten, updated, or written in addition. The information, signals, etc. that are output may also be deleted. The input information, signal, and the like may be transmitted to another device.

The information notification is not limited to the embodiment described in the present disclosure, and may be performed by other methods. For example, the Information may be notified by physical layer signaling (e.g., Downlink Control Information (DCI)), Uplink Control Information (UCI), higher layer signaling (e.g., RRC (Radio Resource Control)) signaling, broadcast Information (Master Information Block, SIB (System Information Block), etc.), MAC (Medium Access Control) signaling), other signals, or a combination thereof.

In addition, physical Layer signaling may also be referred to as L1/L2 (Layer1/Layer 2(Layer1/Layer2)) control information (L1/L2 control signals), L1 control information (L1 control signals), and the like. The RRC signaling may be referred to as an RRC message, and may be, for example, an RRC connection setup (RRCConnectionSetup) message, an RRC connection reconfiguration (RRCConnectionReconfiguration) message, or the like. Further, the MAC signaling may be notified using a MAC Control Element (MAC CE (Control Element)), for example.

Note that the notification of the specific information (for example, the notification of "X") is not limited to an explicit notification, and may be performed implicitly (for example, by not performing the notification of the specific information or by performing the notification of another information).

The determination may be performed by a value (0 or 1) expressed by 1 bit, a true-false value (boolean value) expressed by true (true) or false (false), or a comparison of numerical values (for example, a comparison with a specific value).

Software shall be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software modules, applications, software packages, routines, subroutines, objects (objects), executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names.

In addition, software, instructions, information, and the like may also be transmitted or received via a transmission medium. For example, in the case where software is transmitted from a website, server, or other remote source using at least one of a wired technology (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and a wireless technology (infrared, microwave, etc.), at least one of these wired and wireless technologies is included in the definition of transmission medium.

The terms "system" and "network" as used in this disclosure are used interchangeably.

In the present disclosure, terms such as "precoding", "precoder", "weight (precoding weight)", "transmission power", "phase rotation", "antenna port group", "layer number", "rank", "beam width", "beam angle", "antenna element", "panel", and the like can be used interchangeably.

In the present disclosure, terms such as "Base Station (BS)", "wireless Base Station", "fixed Station (fixed Station)", "NodeB", "enodeb (enb)", "gbnodeb (gnb)", "access Point (access Point)", "Transmission Point (TP)", "Reception Point (RP)", "Transmission Point (TRP)", "panel", "cell", "sector", "cell group", "carrier", "component carrier" can be used interchangeably. A base station is also sometimes referred to by the terms macrocell, smallcell, femtocell, picocell, and the like.

A base station can accommodate one or more (e.g., three) cells. In the case where a base station accommodates a plurality of cells, the coverage area of the base station as a whole can be divided into a plurality of smaller areas, and each smaller area can also provide a communication service through a base station subsystem (e.g., an indoor small base station (RRH): Remote Radio Head) — "cell" or "sector" which is a term referring to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that performs a communication service in the coverage area.

In the present disclosure, terms such as "Mobile Station (MS)", "User terminal (User terminal)", "User Equipment (UE)", "terminal" and the like can be used interchangeably.

A mobile station is also sometimes referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset (hand set), user agent, mobile client, or some other appropriate terminology.

At least one of the base station and the mobile station may be referred to as a transmitting apparatus, a receiving apparatus, or the like. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, or the like. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving body (e.g., an unmanned aerial vehicle, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station includes a device that does not necessarily move during a communication operation.

In addition, the base station in the present disclosure may also be replaced with a user terminal. For example, the aspects and embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between a plurality of user terminals (for example, D2D (Device-to-Device), V2X (Vehicle-to-event), and the like may be used). In this case, the user terminal 20 may have the functions of the base station 10 described above. The language such as "uplink" or "downlink" may be replaced with a language (e.g., "side") corresponding to inter-terminal communication. For example, the uplink channel, the downlink channel, and the like may be replaced with the side channel.

Also, the user terminal in the present disclosure may be replaced with a base station. In this case, the base station 10 may have the functions of the user terminal 20 described above.

In the present disclosure, it is assumed that the operation performed by the base station is also performed by its upper node (upper node) depending on the case. In a network including one or more network nodes (network nodes) having a base station, it is apparent that various operations performed for communication with a terminal can be performed by the base station, one or more network nodes other than the base station (for example, consider MME (Mobility Management Entity), S-GW (Serving-Gateway), and the like, but not limited thereto), or a combination thereof.

The aspects and embodiments described in the present disclosure may be used alone, may be used in combination, or may be switched to use with execution. Note that the order of the processing procedures, sequences, flowcharts, and the like of the respective modes/embodiments described in the present disclosure may be changed as long as there is no contradiction. For example, elements of various steps are presented in an exemplary order for the method described in the present disclosure, and the order is not limited to the specific order presented.

The aspects/embodiments described in the present disclosure may also be applied to LTE (Long Term Evolution), LTE-a (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (fourth generation Mobile communication System), 5G (fifth generation Mobile communication System), FRA (Future Radio Access), New-RAT (Radio Access Technology), NR (New Radio), NX (New Radio Access), FX (Future Radio Access), GSM (registered trademark) (Global System for Mobile communication), and CDMA (Radio Broadband) SUPER Mobile communication System (CDMA 2000) IEEE 802.11(Wi-Fi (registered trademark)), IEEE 802.16(WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), a system using other appropriate wireless communication method, a next generation system extended based on them, and the like. Further, a combination of a plurality of systems (for example, LTE, or a combination of LTE-a and 5G) may be applied.

The expression "based on" used in the present disclosure does not mean "based only on" unless explicitly stated otherwise. In other words, the expression "based on" means both "based only on" and "based at least on".

Any reference to an element using the designations "first," "second," etc. used in this disclosure is not intended to be a comprehensive limitation on the quantity or order of such elements. These designations can be used in the present disclosure as a convenient method of distinguishing between two or more elements. Thus, reference to first and second elements does not imply that only two elements can be used or that in some form the first element must precede the second element.

The term "determining" used in the present disclosure sometimes includes various operations. For example, "determining" may be considered as "determining" a determination (e.g., a determination), a calculation (calculating), a processing (processing), a derivation (deriving), an investigation (investigating), a search (logging) (e.g., a search in a table, a database, or another data structure), a confirmation (authenticating), or the like.

The term "determination (decision)" may be also referred to as "determining (deciding)" on reception (e.g., reception information), transmission (e.g., transmission information), input (input), output (output), access (e.g., access to data in a memory), and the like.

The "determination (decision)" may be regarded as "determination (decision)" performed for solving (resolving), selecting (selecting), selecting (breathing), establishing (evaluating), comparing (comparing), and the like. That is, "judgment (decision)" may also be regarded as "judgment (decision)" performed on some operation.

The "determination (decision)" may be replaced with "assumption", "expectation", "consideration", and the like.

The term "connected" or "coupled" or any variant thereof used in the present disclosure means all direct or indirect connections or couplings between 2 or more elements, and can include 1 or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between the elements may be physical, logical, or a combination thereof. For example, "connected" may also be replaced with "accessed".

In the present disclosure, when two elements are connected, it is possible to consider that one or more electric wires, cables, printed electric connections, and the like are used, and as some non-limiting (non-limiting) and non-inclusive examples, electromagnetic energy of wavelengths in a radio frequency domain, a microwave domain, and an optical (both visible and invisible) domain, and the like are used, and the two elements are "connected" or "coupled" to each other.

In the present disclosure, the term "a is different from B" may also mean "a and B are different from each other". In addition, the term may also mean "a and B are different from C, respectively". The terms "separate", "combine", and the like are also to be construed as similar to "different".

When the terms "include", "including", and "including" and their variants are used in the present disclosure, these terms are intended to be inclusive in the same way as the term "comprising". Further, the term "or" as used in this disclosure means not exclusive or.

In the present disclosure, where articles are added as a result of translation, such as a, an, and the in english, the present disclosure may also include nouns that follow the articles in plural forms.

While the invention according to the present disclosure has been described in detail, it will be apparent to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented as a modification and a variation without departing from the spirit and scope of the invention defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes, and the invention according to the present disclosure is not intended to be limited thereto.