CN117837264A - Terminal, wireless communication method and base station - Google Patents

Abstract

The terminal according to one aspect of the present disclosure includes: a receiving unit that calculates a radio link quality corresponding to one or more reference signals; a control unit configured to detect a predicted beam failure based on a predicted radio link quality at a future time calculated from the radio link quality; and a transmission unit that transmits an uplink shared channel for predicted beam failure recovery triggered based on the detection of the predicted beam failure. According to one aspect of the present disclosure, appropriate maintenance of communication quality can be achieved.

Description

Terminal, wireless communication method and base station

Technical Field

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

Background

In a universal mobile telecommunications system (Universal Mobile Telecommunications System (UMTS)) network, long term evolution (Long Term Evolution (LTE)) has been standardized for the purpose of further high-speed data rates, low latency, and the like (non-patent document 1). Further, for the purpose of further large capacity, high altitude, and the like of LTE (third generation partnership project (Third Generation Partnership Project (3 GPP)) Release (rel.) 8, 9), LTE-Advanced (3 GPP rel.10-14) has been standardized.

Subsequent systems of LTE (e.g., also referred to as fifth generation mobile communication system (5 th generation mobile communication system (5G)), 5g+ (plus), sixth generation mobile communication system (6 th generation mobile communication system (6G)), new Radio (NR)), 3gpp rel.15 later, and the like are also being studied.

Prior art literature

Non-patent literature

Non-patent document 1:3GPP TS 36.300V8.12.0"Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); overall description; stage 2 (Release 8) ", 4 th 2010

Disclosure of Invention

Problems to be solved by the invention

Regarding future wireless communication technologies, artificial intelligence (Artificial Intelligence (AI)) technologies such as Machine Learning (ML)) are being discussed, which flexibly apply to control, management, etc. of networks/devices. For example, AI-assisted beam management using AI-assisted estimation (AI-assisted estimation) is being discussed.

However, the specific content of AI-assisted beam management has not been discussed. If these are not properly specified, there is a concern that improvement in communication throughput or communication quality is suppressed.

Accordingly, an object of the present disclosure is to provide a terminal, a wireless communication method, and a base station capable of achieving appropriate maintenance of communication quality.

Means for solving the problems

The terminal according to one aspect of the present disclosure includes: a receiving unit that calculates a radio link quality corresponding to one or more reference signals; a control unit configured to detect a predicted beam failure based on a predicted radio link quality at a future time calculated from the radio link quality; and a transmission unit that transmits an uplink shared channel for predicted beam failure recovery triggered based on the detection of the predicted beam failure.

Effects of the invention

According to one aspect of the present disclosure, appropriate maintenance of communication quality can be achieved.

Drawings

Fig. 1 is a diagram showing an example of measurement for predicting BFR.

Fig. 2 is a diagram showing an example of predicting BFR.

Fig. 3 is a diagram showing an example of the predicted BFR procedure according to the first embodiment.

Fig. 4 is a diagram showing an example of control of prediction association according to the first embodiment.

Fig. 5 is a diagram showing an example of control of prediction association according to the first embodiment.

Fig. 6 is a diagram showing an example of control of prediction association according to the first embodiment.

Fig. 7 is a diagram showing an example of time for performing prediction BFR.

Fig. 8A and 8B are diagrams showing an example of quantized time information for performing prediction BFR.

Fig. 9A and 9B are diagrams showing an example of a time length that can be used for prediction.

Fig. 10 is a diagram showing an example of calculation of prediction accuracy.

Fig. 11 is a diagram showing an example of calculation of prediction accuracy.

Fig. 12 is a diagram showing an example of calculation of future prediction accuracy information.

Fig. 13 is a diagram showing an example of the reception of predicted BFR reception information according to embodiment 1.5.

Fig. 14 is a diagram showing an example of the application timing of the predicted BFR according to embodiment 1.6.

Fig. 15 is a diagram showing an example of a predicted BFR procedure according to the second embodiment.

Fig. 16 is a diagram showing an example of predicted BFR MAC CE according to embodiment 2.3.

Fig. 17 is a diagram showing an example of the BFR and the priority control of the predicted BFR according to the third embodiment.

Fig. 18 is a diagram showing an example of a schematic configuration of a radio communication system according to an embodiment.

Fig. 19 is a diagram showing an example of a configuration of a base station according to an embodiment.

Fig. 20 is a diagram showing an example of a configuration of a user terminal according to an embodiment.

Fig. 21 is a diagram showing an example of a hardware configuration of a base station and a user terminal according to an embodiment.

Detailed Description

Application of artificial intelligence (Artificial Intelligence (AI)) technology to wireless communication

With respect to future wireless communication technologies, flexible application of AI technology for control, management, etc. of networks/devices is being discussed.

For example, in future wireless communication technologies, particularly in communication using beams, it is desired to improve the accuracy of channel estimation (which may also be referred to as channel measurement) for beam management, decoding of received signals, and the like.

The channel estimation may be performed using at least one of a channel state information reference signal (Channel State Information Reference Signal (CSI-RS)), a synchronization signal (Synchronization Signal (SS)), a synchronization signal/broadcast channel (Synchronization Signal/Physical Broadcast Channel (SS/PBCH)) block, a demodulation reference signal (DeModulation Reference Signal (DMRS)), a measurement reference signal (sounding reference signal (Sounding Reference Signal (SRS)), and the like, for example.

In the conventional wireless communication technology, a large amount of estimation resources (for example, resources for transmitting reference signals) are required for performing channel estimation with high accuracy, and channel estimation for all antenna ports to be used is required. If resources of DMRS, CSI-RS, etc. are increased for the realization of high-precision channel estimation, resources for data transmission and reception, for example, downlink shared channel (physical downlink shared channel (Physical Downlink Shared Channel (PDSCH))) resources, uplink shared channel (physical uplink shared channel (Physical Uplink Shared Channel (PUSCH)) resources, are reduced.

In addition, in the wireless communication technology up to now, control based on the existing or past measurement results is possible, but in the case of link disconnection or the like due to degradation of wireless quality, its handling becomes slow.

In the future, AI technology such as Machine Learning (ML) is being discussed for high-precision channel estimation with fewer resources and prediction of future measurements. Such channel estimation may also be referred to as AI-assisted estimation (AI-assisted estimation). Beam management using AI-assisted estimation may also be referred to as AI-assisted beam management.

As an example of AI-assisted beam management, when AI is utilized in a terminal (which may also be referred to as a User terminal, user Equipment (UE)), or the like, AI may also predict future beam measurements. In addition, the UE may also trigger a predicted enhanced beam failure recovery (enhanced beam failure recovery (enhanced BFR)).

As an example of AI-assisted beam management, when AI is used in a Base Station (BS), AI may predict future beam measurement values (for example, measurement values of beamlets) or estimate (derive) measurement values of beamlets based on a small amount of beam management. In addition, the UE may also receive a beam indication with a time offset.

However, the specific content regarding AI-assisted beam management has not been discussed. If these are not properly specified, there is a concern that improvement in communication throughput or communication quality is suppressed.

Accordingly, the inventors of the present invention have conceived an appropriate control method and the like for BFR having prediction. In addition, embodiments of the present disclosure may also be applied to cases where AI/prediction is not utilized.

In an embodiment of the present disclosure, the UE/BS learns the ML model in a training mode (training mode), and implements the ML model in a test mode (which may also be referred to as test mode, testing mode, etc.). In the test mode, verification (validation) of accuracy of the ML model (trained ML model) after training in the training mode may be performed.

In the present disclosure, the UE/BS inputs channel state information, reference signal measurement values, etc., for the ML model, outputs high-precision channel state information/measurement values/beam selection/location, future channel state information/radio link quality, etc.

In addition, in the present disclosure, AI may also be rewritten as an object (may also be referred to as an object, data, a function, a program, or the like) having (implementing) at least one of the following features:

An estimate based on the observed or collected information;

selection based on observed or collected information;

prediction based on observed or collected information.

In the present disclosure, the object may be, for example, a terminal, a base station, or other device, equipment, or the like. The object may correspond to a program included in the apparatus.

Further, in the present disclosure, the ML model may also be rewritten as an object having (implementing) at least one of the following features:

generating an estimated value by providing (feeding) information;

predicting an estimate by providing information;

by providing information, discovering features;

by providing information, select operation.

In addition, in the present disclosure, the ML model may also be rewritten as at least one of an AI model, a predictive analysis (predictive analytics), a predictive analysis model, and the like. In addition, the ML model may also be derived using at least one of regression analysis (e.g., linear regression analysis, multi-distance regression analysis, logistic regression analysis), support vector machine, random Forest (Random Forest), neural network, deep learning, etc. In the present disclosure, the model may also be rewritten as at least one of an encoder, a decoder, a tool, and the like.

The ML model outputs information of at least one of an estimated value, a predicted value, a selected operation, a classification, and the like based on the input information.

The ML model may include supervised learning (supervised learning), unsupervised learning (unsupervised learning), reinforcement learning (Reinforcement learning), and the like. Supervised learning may also be utilized for learning general rules that map inputs to outputs. Unsupervised learning may also be utilized for learning features of the data. Reinforcement learning may also be utilized for learning operations for maximizing the purpose.

The embodiments described below will mainly be described assuming that the ML model is learned by supervised learning, but the embodiments are not limited to this.

In this disclosure, implementations, operations, executions, etc. may also be rewritten with each other. In addition, in the present disclosure, test, after training (after-training), actual use, and the like may be rewritten with each other. Signals may also be rewritten with signals/channels.

In the present disclosure, the training mode may also correspond to a mode in which the UE/BS transmits/receives signals for the ML model (in other words, an operation mode during training). In the present disclosure, the test mode may also correspond to a mode in which the UE/BS implements the ML model (e.g., implements the trained ML model to predict the output) (in other words, an operation mode during the test).

In the present disclosure, the training mode may also mean a mode in which a specific signal transmitted through the test mode is transmitted with a large overhead (for example, a large amount of resources).

In the present disclosure, the training mode may also mean a mode with reference to a first setting (e.g., a first DMRS setting, a first CSI-RS setting). In the present disclosure, the test mode may also mean a mode in which a second setting (e.g., a second DMRS setting, a second CSI-RS setting) different from the first setting is referred to. The first setting is set to be larger in at least one of time resource, frequency resource, code resource, and port (antenna port) related to measurement than the second setting.

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

In the following embodiments, for explaining the ML model related to communication between the UE-BS, the subjects of association are the UE and the BS, but the application of the embodiments of the present disclosure is not limited thereto. For example, for other inter-body communications (e.g., UE-UE communications), the UEs and BSs of the following embodiments may be rewritten to the first UE and the second UE. In other words, the UE, BS, etc. of the present disclosure may be rewritten as arbitrary UE/BS.

In the present disclosure, "a/B", "at least one of a and B" may also be rewritten with each other.

In the present disclosure, activation, deactivation, indication (or designation), selection, setting (configuration), update (update), decision (determination), and the like may also be rewritten to each other. In the present disclosure, support, control, enable control, operate, enable operation, and these may also be rewritten with each other.

In the present disclosure, radio resource control (Radio Resource Control (RRC)), RRC parameters, RRC messages, higher layer parameters, information Elements (IEs), settings, which may also be rewritten to each other. In the present disclosure, a media access Control Element (MAC (Medium Access Control) Control Element (CE)), an update command, an activate/deactivate command, which may also be rewritten to each other.

In the present disclosure, a panel, a UE panel, a panel group, a beam group, a precoder, an Uplink (UL)) transmitting entity, TRP, spatial Relationship Information (SRI), spatial relationship, SRS resource indicator (SRS Resource Indicator (SRI)), SRS resource, control resource set (COntrol Resource SET (CORESET)), physical downlink shared channel (Physical Downlink Shared Channel (PDSCH)), codeword, base station, specific antenna port (e.g., demodulation reference signal (DeModulation Reference Signal (DMRS)) port), specific antenna port group (e.g., DMRS port group), specific group (e.g., code division multiplexing (Code Division Multiplexing (CDM)) group, specific reference signal group, CORESET group), specific resource (e.g., specific reference signal resource), specific resource set (e.g., specific reference signal resource set), CORESET, PUCCH resource set (PUCCH resource set), spatial relationship set, TCI state (DL TCI state), TCI state (TCI state) of Uplink, uniform TCI state (unified TCI state), common TCI state (TCI), qcif-qcif (qcif), and the like are also contemplated to be rewritten by each other.

In the present disclosure, the index, the ID, the indicator, and the resource ID may also be rewritten with each other. In this disclosure, sequences, lists, sets, groups, clusters, subsets, etc. may also be rewritten with each other.

In the present disclosure, the CSI-RS may also be rewritten with at least one of a Non Zero Power (NZP) CSI-RS, a Zero Power (ZP) CSI-RS, and a CSI interference measurement (CSI Interference Measurement (CSI-IM)).

In the present disclosure, the RS being measured/reported may also mean the RS being measured/reported in order to predict BFR.

(Wireless communication method)

In the following embodiments, the UE may also trigger a predicted enhanced BFR (which may also be referred to as a predicted BFR). Hereinafter, the predicted BFR, predicted BFR (predicted BFR (predicted BFR)), enhanced BFR (enhanced BFR), future BFR (future BFR), recommended TCI status indication, recommended beam indication, and the like may be rewritten with each other.

Fig. 1 is a diagram showing an example of measurement for predicting BFR. In this example, the BS is transmitting an RS (SSB/CSI-RS), and the UE with AI predicts future beam failure based on beam measurement (L1-RSRP measurement). The RS may be, for example, CSI-RS or SSB.

The UE monitors the RS and calculates the predicted radio link quality. The UE determines whether to trigger a predicted BFR based on the predicted radio link quality.

Fig. 2 is a diagram showing an example of predicting BFR. In this example, the UE predicted that a beam failure will occur in the future in the current beam reports information about the candidate RS together with the time offset (when to switch to the beam for the candidate RS) as a predicted BFR request. Thereafter, the UE receives information indicating that the predicted BFR is accepted by the base station. The UE and the BS switch to the beam for the candidate RS at timing based on the time offset. This can suppress occurrence of beam failure in advance. The occurrence of the beam failure may be rewritten with the detection of the beam failure.

In addition, in the present disclosure, timing, time, slot, sub-slot, symbol, sub-frame, etc. may also be rewritten with each other.

The following embodiments relate to predicting the content, processing, timing of occurrence, etc. of BFRs.

< first embodiment >

The first embodiment relates to a predicted BFR procedure triggered with a physical random access channel (Physical Random Access Channel (PRACH)).

The predictive BFR process of the first embodiment may be broadly divided into the following embodiments:

embodiment 1.1: future radio link quality assessment (assss);

embodiment 1.2: triggering by means of predicted BFR of PRACH;

Embodiment 1.3: reporting when beam scanning should be performed;

embodiment 1.4: reporting of prediction accuracy;

embodiment 1.5: reception of information indicating a situation in which the predicted BFR is accepted by the base station;

embodiment 1.6: the predicted BFR acknowledges the transmission of the received signal (update of QCL/spatial relationship).

The PRACH transmission and the BFR response reception may be performed in a cell different from the cell to which the predicted beam fails (the cell to which the candidate RS belongs). The predicted BFR response may be a Random Access Response (RAR) transmitted according to the PRACH for predicting BFR of embodiment 1.2.

Fig. 3 is a diagram showing an example of the predicted BFR procedure according to the first embodiment. In embodiment 1.1, for example, it is predicted whether or not all beams are smaller than a threshold value. When predicted in this way, the UE selects a candidate beam (candidate RS) for which the predicted L1-RSRP/SINR is the largest. In embodiment 1.2, the UE transmits PRACH at the PRACH opportunity associated with the candidate beam. In addition, "candidates" in the present disclosure may also be rewritten with "prediction candidates".

The UE may receive the predicted BFR response according to embodiment 1.5 or may report embodiment 1.3/1.4, as needed. In embodiment 1.6, after the BFR response reception is predicted, the QCL/spatial relationship for the specific signal may be updated.

Hereinafter, embodiment modes 1.1 to 1.6 will be described.

Embodiment 1.1

In embodiment 1.1, the UE evaluates future radio link quality based on a specific RS. For example, the UE may calculate the radio link quality corresponding to a specific RS and predict the future radio link quality based on the radio link quality (current radio link quality). This future radio link quality may also be referred to as a predicted radio link quality. The predicted radio link quality may be obtained based on a specific RS (the current radio link quality is not calculated).

The specific RS may be an RS corresponding to an RS index (or a set of RS indices) set by a higher layer parameter for evaluating future radio link quality. The RS index may be a CSI-RS resource set ID or an SSR index.

These RS indexes may be the same as those specified by at least one of RRC parameters (for example, failuredetection resource) indicating resources for failure detection and RRC parameters (for example, candidateBeamRSList, candidateBeamRSListExt, candidateBeamRSSCellList, etc.) indicating candidate beam RSs.

The specific RS may be an RS implicitly determined by RRC setting. For example, the UE may also evaluate future radio link quality using an RS represented by the TCI state of CORESET of the PDCCH monitored by the UE. In addition, in the case where 2 or more RSs are included in one TCI state, the UE may decide which RS to refer to based on a specific QCL type (e.g., type D).

The UE may also detect future beam failures/beam candidates based on future specific radio link quality.

The specific radio link quality may be prediction Layer 1 (L1)) -reference signal received power (Reference Signal Received Power (RSRP)) (reference signal received power of Layer 1), virtual (downlink) L1-RSRP, or Block Error Rate (BLER) of predicted virtual (downlink) PDCCH transmission. In the present disclosure, the radio link quality may also be at least one of L1-RSRP, L1-signal-to-interference plus noise ratio (L1-Signal to Interference plus Noise Ratio (SINR)), BLER, etc.

The UE may also detect future beam failures/beam candidates for more than one (e.g., all) of the above-mentioned specific RSs, depending on whether the future specific radio link quality is above or below a threshold. For example, the UE may determine that a predicted beam failure has occurred for one or more RSs among the specific RSs, if the future specific radio link quality is smaller than a threshold value, and notify the predicted beam failure instance through a higher layer (MAC layer). The UE may determine that the predicted beam failure occurs if a counter counted based on the reception of the instance exceeds a certain value in the MAC layer.

The UE may decide the threshold based on a specific rule, may decide based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or may decide based on UE capabilities. The threshold value may be equal to the threshold value for BFR defined in the conventional rel.15/16 NR.

The time for predicting the L1-RSRP (future time) by the UE may be determined based on a specific rule, may be determined based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or may be determined based on UE capability.

The detection of the UE with respect to beam failure/candidate beam for predicting BFR may also be performed if a condition based on at least one of the following is met:

parameters related to the number of beam failure events (instances) after triggering the predicted BFR (e.g., beamFailureInstanceMaxCount);

parameters related to the above threshold (e.g., rlmInSyncOutOfSyncThreshold, rsrp-ThresholdSSB, rsrp-threshold BFR);

wave corresponding to the period during which the number of beam failure events for predicting the PFR is checked

A beam failure detection timer.

The UE may determine these parameters separately from or based on the parameters of the BFR. For example, the UE may set information about the differential value of the BFR and the predicted BFR by higher-layer parameters with respect to the above parameters.

Fig. 4 is a diagram showing an example of control of prediction association according to the first embodiment. If the UE monitors an RS (SSB/CSI-RS) to detect a predicted beam failure, the UE starts a beam failure detection timer, and if a predicted beam failure occurs a specific number of times (for example, X times) before the timer expires, the UE triggers a predicted BFR.

[ [ prediction time ] ]

The UE may also predict an estimated/predicted radio link quality in a future time (which may also be referred to as a predicted time, a predicted timing, etc.) based on current/past RS measurements.

Fig. 5 is a diagram showing an example of control of prediction association according to the first embodiment. The UE monitors an RS (SSB/CSI-RS) and predicts a radio link quality at a predicted time after a time offset (time offset) from a certain timing.

Here, the certain timing may be a current time (present/current time) at which the UE performs radio link quality prediction, or may be a reception timing of a specific RS measured for prediction (for example, a last reception timing of a specific RS). The time shift amount in the former case corresponds to the illustrated period a, and the time shift amount in the latter case corresponds to the illustrated period B. This timing may also be referred to as a reference time (reference time).

The time offset may be expressed in units of time slots, for example, or in units of seconds (for example, units of milliseconds).

The UE may determine the time offset based on a specific rule, based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or based on UE capability.

In addition, when the time offset is not set, the UE may autonomously determine the predicted time or may determine that the predicted time is the default predicted time.

In addition, in the present disclosure, the predicted time and the time offset may also be rewritten to each other.

In the operation of the beam failure timer (for example, the beam failure detection timer may be a beam failure detection timer or another timer), the UE may perform prediction based on the RS at different current times, or may evaluate the predicted radio link quality at the same predicted time.

In addition, in the beam failure timer operation, the UE may evaluate the predicted radio link quality at different predicted times to which the time offset is applied, respectively, for predictions of RSs based on different current times.

The UE may also trigger the predicted BFR if the predicted beam failure is detected more than a certain number of times in the beam failure timer.

Fig. 6 is a diagram showing an example of control of prediction association according to the first embodiment. This example is similar to fig. 4, except that it shows whether the predicted radio link quality in the timer start is predicted for the same time or for different times. In the case of predicting the radio link quality for the same time in the future, the measurement RS becomes closer to the same time in the future at each measurement, and thus improvement in the prediction accuracy is expected. In case the predicted radio link quality is predicted for different times in the future, the predicted beam failure can be detected by predicting that the beam failure is also sustained for different times.

Embodiment 1.2

In embodiment 1.2, the UE may predict the BFR using PRACH triggers based on embodiment 1.1. This PRACH for predicting BFR may be referred to as a PRACH for predicting BFR requests, and may also be referred to as a predicted BFR request.

The UE may also trigger the predicted BFR using PRACH resources associated with candidate RSs (CSI-RS/SSBs) that recommend handover to the BS in the future. In addition, PRACH resources may also mean at least one of time/frequency resources of PRACH (e.g., PRACH opportunities), PRACH index, sequence of PRACH, etc.

The PRACH resource may be a PRACH resource that is set exclusively for predicting BFR, or may be a PRACH resource that is set for BFR in the related art.

The UE may also trigger the predictive BFR using a Contention-based random access (CBRA) procedure. In this case, the UE may transmit PRACH on PRACH resources set in association with the candidate RS for predicting BFR or the RS achieving the highest radio link quality.

The UE may also transmit not only the C-RNTI but also information of candidate RSs recommending handover to the BS in the future, using PUSCH (message 3) scheduled by UL grant of Random Access Response (RAR). This information may be sent using a MAC CE, as will be described in the second embodiment.

The UE may also be set by higher layer parameters to enable triggering of PRACH-based predictive BFR.

The UE may also trigger the predictive BFR using a Contention-free random access (CFRA) procedure.

Embodiment 1.3

In embodiment 1.3, the UE may report information on the time at which beam scanning should be performed. The "performing beam scanning" may be rewritten with "applying (performing) prediction BFR", "base station switching beam", "base station transmission candidate RS", and the like.

[ [ contention-free random Access procedure ] ]

The UE may monitor a PDCCH for allocating PUSCH resources for reporting PRACH (or beam switching timing after PRACH transmission. The PDCCH may also be monitored in CORESET associated with a Search Space (SS) set for the predicted BFR or an SS set for the BFR (corresponding to the RRC parameter recoverysearchspace).

The UE may also report information about the time at which beam scanning should be performed using PUSCH. Such information may also be sent using a MAC CE. These are described in the second embodiment.

In addition, when the time for which beam scanning should be performed is set or determined according to a specific rule, reporting of information about the time may be omitted.

[ [ contention-based random Access procedure ] ]

The UE may also transmit not only the C-RNTI but also information for activating the time offset of the predicted BFR (information about the time at which beam scanning should be performed) using PUSCH (message 3) scheduled by UL grant of Random Access Response (RAR). This information may also be sent using MAC CEs. Regarding this, the second embodiment will be described.

[ [ time to predict BFR ] ]

The UE may also be set with higher layer parameters regarding the time offset between signaling of the predicted BFR and the time when the predicted BFR is implemented (applied) (as will be described in embodiment 1.5).

The UE may also report a time offset between signaling related to the predicted BFR and the time the predicted BFR was applied.

In addition, the signaling related to the predicted BFR may also be at least one of:

(most recent) RS for calculating the predicted radio link quality;

PRACH/scheduling request (Scheduling Request (SR))/MAC CE/PUSCH for predicting BFR;

predicting BFR responses.

The UE may also apply the predictive BFR at least one of the following timings:

y symbols from the last symbol of signaling related to predicted BFR + time offset;

time offset from the last symbol of signaling related to predicted BFR;

from the last symbol of the signaling related to the predicted BFR, the maximum of the time offset + a certain number (e.g., 28) symbols later.

The value of Y may be determined by a specific rule, by physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or by UE capability.

In the present disclosure, the predicted time may also be rewritten to at least one of the above timings.

Fig. 7 is a diagram showing an example of time for performing prediction BFR.

The period 1 illustrated corresponds to (the maximum value of) the time offset of 28 symbols in the following cases: that is, the signaling related to the predicted BFR is the (most up-to-date) RS used to calculate the predicted radio link quality.

Period 2 corresponds to (maximum value of) time offset) +28 symbols in case the signaling related to the predicted BFR is a trigger of the predicted BFR (e.g., PRACH/SR/MAC CE/PUSCH transmission for the predicted BFR).

Period 3 corresponds to (maximum of) time offset +28 symbols in case the signaling related to the predicted BFR is a predicted BFR response.

Fig. 8A and 8B are diagrams showing an example of information in which the time for performing prediction BFR is quantized.

The UE may transmit a bit field indicating one time offset selected from the set time offsets as information of a time at which the predicted BFR is implemented. In fig. 8A, the UE envisages four time offsets (12, 14, 16 and 18 slots) corresponding to the bit fields being set with RRC parameters.

In addition, when the UE is set with only one time offset, the UE may not transmit information of the time at which the predicted BFR is performed (because the base station grasps the time offset assumed by the UE).

The UE may transmit a bit field indicating one time offset selected from the predetermined time offsets as information of a time at which the prediction BFR is performed. In fig. 8B, for example, four time offsets (2, 4, 6, 8 slots) corresponding to each bit field may be specified in advance in the specification.

In addition, in the case that the UE processes the time offset, the UE may also determine a time duration (time duration) available for prediction based on the time offset. The time to implement the predictive BFR may also be more than one during the length of time.

In the present disclosure, in order to determine the time length, the UE may report/receive/decide/set the time offset and the window size instead of the time offset.

The UE may also predict the radio link quality in a particular time instant (e.g., a particular time slot) during a time length specified by the time offset and window size.

In addition, in the present disclosure, in order to determine the above-described time length, the UE may report/receive/decide/be set with 2 time offsets instead of one time offset.

The UE may also predict the radio link quality in a particular time instant (e.g., a particular time slot) during a time length specified by 2 time offsets.

Fig. 9A and 9B are diagrams showing an example of the time length available for prediction.

Fig. 9A shows an example in which the time length is specified by the time offset and the window size. The time period may be at least one of the periods a to C shown in the drawing. The period a is a window-size-width period (period after the point) having a point (time T) determined by a time offset with reference to a reference time as a start time. The period B is a window-size-width period (period before the point) having a point (time T) determined by a time offset with reference to the reference time as the end time. The period C is a period (including a period before and after the point) of the window size width with the point (time T) determined by the time offset with reference to the reference time as the center of the window size width.

Fig. 9B shows an example in which the time length is specified by 2 time offsets (first time offset, second time offset). The length of time may also be the duration of the illustration. The period is a period in which one of a point determined by the first time offset with reference to the reference time and a point determined by the second time offset with reference to the reference time is set as the start time and the other is set as the end time. For example, let the second time offset (e.g., Z slots) > the first time offset (e.g., X slots), the length of the period can be represented by Z-X.

Embodiment 1.4

[ [ report of prediction accuracy ] ]

The UE may report information on the prediction accuracy (hereinafter, also referred to as prediction accuracy information). The prediction accuracy information may include information on the accuracy of past predictions (past prediction performance) (hereinafter, also referred to as past prediction accuracy information), or may include information on the expected accuracy of future predictions (expected performance) (hereinafter, also referred to as future prediction accuracy information).

The past prediction accuracy information may be at least one of:

information of unpredicted measured radio link quality for the reported information of predicted radio link quality;

information indicating whether the predicted error is included in a certain range;

average performance error.

Here, the information of the non-predicted measured radio link quality with respect to the information of the predicted radio link quality reported above may be equivalent to the information of the non-predicted radio link quality based on the measurement at the time of the predicted time after the information of the predicted radio link quality with respect to the certain predicted time is transmitted. The UE may report, as the information of the non-predicted radio link quality, a difference value with respect to a predicted value indicated by the reported information of the predicted radio link quality.

The information indicating whether the predicted error is included in a certain range may indicate whether the error is included in an X% reliable section (for example, x=95). This information may be represented in Y bits (e.g., y=1). The predicted error can also be represented by, for example, an error (difference) between the predicted RSRP and the RSRP actually measured at that time.

The UE may determine the certain range based on a specific rule, based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or based on UE capability.

The average performance error may be equivalent to average performance error information obtained by passing a certain time interval or a specific number of measurements.

The UE may determine the time interval or the number of measurements based on a specific rule, may determine the time interval or the number of measurements based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or may determine the time interval or the number of measurements based on UE capability.

Fig. 10 is a diagram showing an example of calculation of prediction accuracy. In this example, three RSRP to be predicted and RSRP to be actually measured at that time are shown for the same rs#1 that has elapsed a certain time. The UE may calculate the average error of the measured RSRP and the predicted RSRP at three time instants in the illustrated period, and report the average error as an average performance error (past prediction accuracy information) to the base station.

The future prediction accuracy information may be at least one of:

expected differences between predicted values (e.g., predicted RSRP) and predicted measured values (e.g., measured RSRP) for the predicted values;

information about the distribution of errors between predicted and actual values;

the range within which Y% of the prediction error falls;

average performance error.

Regarding the range within which Y% of the above-described prediction error falls, for example, in the case where the error of Y% falls within ±3dB, the UE may also report ±3dB.

The UE may determine the Y based on a specific rule, based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or based on UE capability.

The average performance error may be equivalent to average performance error information obtained by a certain time interval or a specific number of measurements.

The UE may determine the time interval or the number of measurements based on a specific rule, may determine the time interval or the number of measurements based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or may determine the time interval or the number of measurements based on UE capability.

Fig. 11 is a diagram showing an example of calculation of prediction accuracy. In this example, the respective predicted values and the ranges within which the prediction errors of 90% fall are shown for RSs (RS #1 to # 3) corresponding to the 3 RS indexes. As future prediction accuracy information, the UE may report information indicating each range.

The UE may report the prediction accuracy information for each RS index, may report the prediction accuracy information for each RS group, or may report the prediction accuracy information for all RS indexes.

The granularity of the expected precision (accuracy) may be determined based on a specific rule, may be determined based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or may be determined based on UE capability.

[ [ timing of reporting of prediction accuracy information ] ]

Prediction accuracy information may also be reported periodically/semi-continuously/aperiodically. The transmission period of the prediction accuracy information may be the same as or different from the transmission period of the prediction beam report (CSI report).

The period and timing of reporting of the prediction accuracy information by the UE may be determined based on a specific rule, may be determined based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or may be determined based on UE capability.

The UE may report the prediction accuracy information if at least one of the following conditions is satisfied: the calculated (or expected) error deviates X times from the specified range;

the calculated (or expected) error is greater than or less than a threshold;

the difference between the reported error (the previously reported prediction accuracy information) and the calculated (or expected) error is greater than a threshold value.

The UE may be determined based on a specific rule, based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, for the specific range, the value of X, the threshold, or the like, or based on UE capability.

The prediction accuracy information may be reported by being included in a predicted BFR MAC CE (described later), or may be reported separately from the predicted BFR MAC CE. The prediction accuracy information may be reported by using, for example, a MAC CE for transmitting the prediction accuracy information.

The UE calculates the accuracy of prediction based on which time point with respect to future prediction accuracy information, and this may be determined based on the above-described time offset. The time offset may be set by RRC, or may correspond to a time offset included in a predicted beam report (CSI report).

Fig. 12 is a diagram showing an example of calculation of future prediction accuracy information. In this example, the UE may derive and report the expected prediction accuracy of the predicted RSRP/SINR at the predicted time after the time offset of +28 symbols from the end of the last symbol of the monitored RS.

Embodiment 1.5

The UE receives information (may also be referred to as predicted BFR accept information) of whether the predicted BFR is accepted by the BS. This information is included in the predicted BFR response and is notified to the UE. In addition, the predicted BFR response may also be transmitted according to the reception of the PRACH for predicting BFR in the BS.

The UE may also predict BFR accept information based on the PDCCH determination. In this case, the RS index need not be included in the predicted BFR response. Specifically, the UE may also determine the predicted BFR accept information based on at least one of:

PDCCH reception of DCI format for PUSCH transmission having the same scheduling HARQ process number as the initial PUSCH transmission (e.g., transmission of predicted BFR MAC CE) and holding the NDI field value after switching;

PDCCH reception within a (RAR) window;

DCI (e.g., DCI field for predicting BFR response).

For example, when the UE receives the PDCCH, it is conceivable that the UE is notified of the reception as predicted BFR reception information.

In addition, the UE may also be set with information on a search space set for monitoring a PDCCH indicating predicted BFR reception information by a higher layer parameter.

The UE may determine the predicted BFR accept information based on the MAC CE via the PDSCH. For example, when the UE receives the MAC CE, it is conceivable that the UE is notified of the reception as predicted BFR reception information.

The MAC CE may also be a predicted BFR MAC CE. In this case, the RS index need not be included in the predicted BFR response. In addition, the MAC CE may also indicate in which cell (primary cell, special cell, secondary cell, etc.) the predicted BFR is accepted.

The MAC CE may be an activation command (activate MAC CE) related to a spatial relationship (spatial relation) of TCI status/PUCCH for PDCCH. In this case, a new MAC CE may not be introduced, and a reduction in UE load and the like may be expected.

For example, the UE may receive an activation command for the RRC parameter PUCCH-spatlrelation info, and may also be provided with PUCCH-spatlrelation info for PUCCH resources.

The UE may receive an activation command of the MAC CE for the TCI state, and may also receive RRC parameters TCI-statepdcch-ToAddList/TCI-statepdcch-torrelease list.

Regarding predicted BFR acceptance information, a window for monitoring PDCCH/receiving MAC CE through PDSCH may also be utilized. The UE may also be set the size/starting point of the window. The window that is set may be used only for predicting BFRs, or may be shared with BFRs (of general Rel.15/16) (set by BeamFailureRecoveryConfig). In this disclosure, a simple "BFR" may also mean a BFR specified in rel.15/16 (e.g., PCell BFR, SCell BFR).

The size/starting point of the window may be determined by a specific rule, by physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or by UE capability.

Fig. 13 is a diagram showing an example of the reception of predicted BFR reception information according to embodiment 1.5. In this example, the UE may expect to receive PDCCH (DCI) indicating predicted BFR reception information in the RAR window after PRACH transmission.

Embodiment 1.6

The UE may also control the transmission of a specific signal after predicting the BFR response reception. For example, the UE may update the QCL/spatial relationship for PUCCH/PDCCH after predicting BFR response reception. In addition, such updating of QCL/spatial relationships may also be referred to as application of predictive BFR. In addition, in the present disclosure, the predicted BFR response and the predicted BFR acceptance information may also be rewritten with each other.

The UE may calculate the transmission power based on the candidate RS for predicting the BFR after the predicted BFR response reception, or may initialize (reset) a closed loop term (for example, correction value/accumulated value based on a transmission power control (Transmit Power Control (TPC)) command) in the calculation formula of the transmission power. In addition, the initialization of an item may also mean setting the value of the item to 0.

In embodiment 1.6, the UE may transmit the PUCCH using the same spatial filter (spatial domain filter) as the last PRACH transmission, or may transmit the PUCCH using the same spatial filter as the spatial filter corresponding to the RS index indicated by the MAC CE (e.g., the predicted BFR MAC CE).

The UE may also monitor the PDCCH in a certain CORESET (e.g., CORESET of index 0) or all CORESETs using the same antenna port QCL as the candidate RS for predicting BFR.

Regarding in which cell the predicted BFR is applied, the UE may also apply the predicted BFR only in the cell that accepted the predicted BFR. Regarding cells that have accepted the predicted BFR, it may also be determined/acknowledged based on at least one of the predicted BFR response and the cell that sent the triggering PRACH.

The UE may also determine as to when to apply the predictive BFR in accordance with at least one of:

After a certain number of symbols/slots from the transmission or reception of the predicted BFR acknowledgement/trigger signal (PRACH/SR/MAC CE);

after a time offset (from transmission or reception of MAC CE/RRC) for activating the predicted BFR in MAC CE or a time offset set by RRC.

The UE may be determined based on a specific rule, based on physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel, or a combination of these, or based on UE capability.

The UE may calculate the time offset based on the parameters of the MAC CE described above, or based on the resources of the predicted BFR procedure (e.g., PRACH/SR/MAC CE/resources of the predicted BFR response).

The time offset may be included in the predicted BFR response and notified.

Fig. 14 is a diagram showing an example of the application timing of the predicted BFR according to embodiment 1.6. Fig. 14 shows an example (case 1) in which predicted BFR is applied after a specific number (X) of symbols from the reception of a predicted BFR response, and an example (case 2) in which predicted BFR is applied after a time offset (Y symbols) indicated by a predicted BFR MAC CE from the transmission of the MAC CE.

According to the first embodiment described above, predictive BFR can be appropriately implemented.

< second embodiment >

The second embodiment relates to a predictive BFR procedure triggered with SR/MAC CE.

The predictive BFR process of the second embodiment may be broadly divided into the following embodiments:

embodiment 2.1: future radio link quality assessment (assss);

embodiment 2.2: triggering by predicted BFR of SR/MAC CE;

embodiment 2.3: predicting BFR MAC CE transmission;

embodiment 2.4: reception of information indicating a predicted BFR accepted by the base station;

embodiment 2.5: the predicted BFR acknowledges the transmission of the received signal (update of QCL/spatial relationship).

The PRACH transmission and the BFR response reception may be performed in a cell different from the cell to which the predicted beam fails (the cell to which the candidate RS belongs). The predicted BFR response may be a Random Access Response (RAR) transmitted by the predicted BFR MAC CE according to embodiment 2.3.

Fig. 15 is a diagram showing an example of a predicted BFR procedure according to the second embodiment. Note that embodiments 2.1, 2.4, and 2.5 may be the same as embodiments 1.1, 1.5, and 1.6, respectively, and thus description thereof will not be repeated.

In embodiment 2.2, the UE may transmit an SR for predicting BFR, if necessary. In embodiment 2.3, the UE transmits the predicted BFR MAC CE.

Hereinafter, embodiments 2.2 and 2.3 will be described.

Embodiment 2.2

In embodiment 2.2, the UE may also predict BFR using SR/MAC CE triggering based on embodiment 2.1. This MAC CE (PUSCH) for predicting the BFR may also be referred to as a MAC CE (PUSCH) for predicting the BFR request, and may also be referred to as a predicting the BFR request.

The UE may also transmit an SR for predicting BFR in order to transmit PUSCH for MAC CE for predicting BFR (predicted BFR MAC CE). Here, the UE may also be provided (set) with a scheduling request ID for predicting the BFR through higher layer parameters. In addition, the UE may determine that the scheduling request ID for predicting BFR is the same as the scheduling request ID for SCell BFR (schedulingRequestID-BFR-SCell) of rel.16.

In addition, the UE may cancel the transmission of the SR in case that the PUSCH resources that can be utilized have been scheduled/allocated.

The UE may also transmit the predicted BFR MAC CE using PUSCH resources. The PUSCH resource may be a resource scheduled by DCI, a grant PUSCSH resource set, or a PUSCH resource set for predicting BFR.

Embodiment 2.3

The predicted BFR MAC CE may also contain at least one of the following information (fields):

information indicating a Cell of the predicted BFR (a Cell in which the predicted beam failure occurred) (a serving Cell index, a Secondary Cell (SCell)) index, and information indicating whether or not the Cell is a Special Cell (SpCell);

information (e.g., RS index) representing candidate RSs;

information indicating the type of RS index (e.g., CSI-RS resource indicator (CSI-RS Resource Indicator (CRI)), SS/PBCH block resource indicator (SS/PBCH Block Indicator (SSBRI)));

time when the predicted beam failure occurs;

time to implement predicted BFR;

information indicating whether to predict or (normally) BFR;

information indicating the presence of candidate RSs;

prediction accuracy information (described in embodiment 1.4).

The RS index of the candidate RS may also correspond to an index of a CSI-RS/SSB resource that the UE recommends to handover or that the measurement result (e.g., L1-RSRP) is above a threshold.

The time at which the predicted beam failure occurs/the time at which the predicted BFR is implemented may also be expressed as a time offset (e.g., slot offset, symbol offset) with respect to the resources of the predicted BFR procedure (e.g., resources of PRACH/SR/MAC CE/predicted BFR response).

The information indicating whether a predicted or (normally) BFR is present in the MAC CE may for example also indicate whether an octet containing information of the time offset is present.

Fig. 16 is a diagram showing an example of predicted BFR MAC CE according to embodiment 2.3. The MAC CE may also contain C _i A field, an SP field, an AC field, a C field, a candidate RS ID field, a slot offset field, a prediction accuracy field, and the like.

C _i The field corresponds to a bit field (e.g., if "1", then failure is detected) that predicts whether a beam failure is detected in the cell representing the serving cell index i. The SP corresponds to a bit field indicating whether a predicted beam failure is detected in a special cell.

The AC field may also indicate whether a candidate RS ID field exists in the same octet. The C field may also indicate whether or not a prediction BFR-oriented octet (e.g., slot offset field, prediction accuracy field) is included. The slot offset field may also indicate the time at which the predicted BFR was implemented. The prediction accuracy field may also represent prediction accuracy information.

The UE may determine that the size of the predicted BFR MAC CE is fixed (predetermined), may determine based on the RRC parameter, or may determine based on a field of the MAC CE.

For example, in the case where the (maximum) set number of serving cells is X (X is an integer), the number of octets showing the bit field for representing the cell of the predicted BFR may also be represented by ceil (X/8). In addition, ceil represents an upward function.

The field of the MAC CE may correspond to at least one of:

the number of fields representing beam failure detection (e.g., the number of fields representing 1 bit of beam failure detection corresponding to a cell);

information indicating whether or not a certain octet exists in the MAC CE (e.g., the C field described above); a field indicating the number of reported beam failures (or a beam failure number field).

The UE includes octets indicating candidate RS IDs, time offsets, cell indexes, and the like in the predicted BFR MAC CE, for example, corresponding to the number of beam failures indicated by the field indicating the number of beam failures to be reported.

According to the second embodiment described above, predictive BFR can be appropriately implemented.

< third embodiment >

The third embodiment relates to control in which the UE supports BFR simultaneously and predicts BFR.

The UE may also notify the base station of whether it is a BFR or a predicted BFR using at least one of:

PRACH resources;

PUCCH resources;

information in the BFR MAC CE indicating whether the BFR is predicted or BFR;

time offset.

For example, the UE may also transmit PRACH for predicting BFR using PRACH resources set to be different from BFR.

The UE may transmit the SR for predicting the BFR using a PUCCH resource set to be different from the BFR.

In addition, the UE may set 0 as a time offset in the case of requesting BFR, and report the time offset.

The UE may also prioritize one of the predicted BFR response and the BFR response. Prioritizing BFR responses corresponds to prioritizing BFRs.

For example, in the case where a BFR is triggered after a predicted BFR and a BFR response is received before the predicted BFR response, the UE may also ignore the predicted BFR (or the predicted BFR corresponding to the serving cell or all cells specified by the predicted BFR). In this case, the UE may also implement the subsequent processing based on the BFR response.

Fig. 17 is a diagram showing an example of the BFR and the priority control of the predicted BFR according to the third embodiment. In this example, where the BFR is triggered after predicting the BFR and the BFR response is received before predicting the BFR response, the UE may also determine that the BFR completed successfully based on the BFR response, and thereafter the spatial relationship/TCI state update is also determined based on the BFR. The UE may ignore the predicted BFR response received after the BFR response, or may not perform PDCCH monitoring for predicting the BFR response after receiving the BFR response.

According to the third embodiment described above, appropriate beam failure recovery can be implemented even in the case where the UE supports both BFR and predicted BFR.

< others >

In the present disclosure, it is assumed that one value illustrates a predicted value, but is not limited thereto. For example, the predicted value may be calculated as a probability density function (Probability Density Function (PDF))/cumulative distribution function (Cumulative Distribution Function (CDF)), and information necessary for representing the PDF/CDF may be reported as the predicted CSI information.

At least one of the above embodiments may also be applied only for UEs reporting or supporting a specific UE Capability (UE Capability).

The particular UE capability may also represent at least one of:

whether or not specific operations/information of the respective embodiments are supported;

the maximum number of cells supporting predicted BFR;

the maximum number of RSs monitored to predict BFR;

the accuracy/performance of the predicted BFR.

The UE capability may be reported per Frequency, per Frequency Range (e.g., frequency Range 1 (FR 1)), frequency Range 2 (RF 2)), FR2-1, FR 2-2), per cell, per UE, per subcarrier interval (SubCarrier Spacing (SCS)).

The UE capability may be reported commonly for time division duplexing (Time Division Duplex (TDD)) and frequency division duplexing (Frequency Division Duplex (FDD)) or may be reported independently.

At least one of the above embodiments may be applied when the UE sets specific information related to the above embodiments by higher layer signaling. For example, the specific information may be information indicating activation of the predicted BFR, an arbitrary RRC parameter for a specific version (e.g., rel.18), or the like.

(Wireless communication System)

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

Fig. 18 is a diagram showing an example of a schematic configuration of a radio communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication by using long term evolution (Long Term Evolution (LTE)) standardized by the third generation partnership project (Third Generation Partnership Project (3 GPP)), the fifth generation mobile communication system new wireless (5 th generation mobile communication system New Radio (5G NR)), or the like.

The wireless communication system 1 may support dual connection (Multi-RAT dual connection (Multi-RAT Dual Connectivity (MR-DC))) between a plurality of radio access technologies (Radio Access Technology (RATs)). MR-DC may also include a dual connection of LTE (evolved universal terrestrial radio Access (Evolved Universal Terrestrial Radio Access (E-UTRA))) with NR (E-UTRA-NR dual connection (E-UTRA-NR Dual Connectivity (EN-DC))), NR with LTE (NR-E-UTRA dual connection (NR-E-UTRA Dual Connectivity (NE-DC))), etc.

In EN-DC, a base station (eNB) of LTE (E-UTRA) is a Master Node (MN), and a base station (gNB) of NR is a Slave Node (SN). In NE-DC, the base station (gNB) of NR is MN and the base station (eNB) of LTE (E-UTRA) is SN.

The wireless communication system 1 may also support dual connections between multiple base stations within the same RAT (e.g., dual connection (NR-NR dual connection (NR-NR Dual Connectivity (NN-DC))) of a base station (gNB) where both MN and SN are NRs).

The radio communication system 1 may include a base station 11 forming a macro cell C1 having a relatively wide coverage area, and base stations 12 (12 a to 12C) arranged in the macro cell C1 and forming a small cell C2 narrower than the macro cell C1. The user terminal 20 may also be located in at least one cell. The arrangement, number, etc. of each cell and user terminal 20 are not limited to those shown in the figure. Hereinafter, the base stations 11 and 12 are collectively referred to as a base station 10 without distinction.

The user terminal 20 may also be connected to at least one of the plurality of base stations 10. The user terminal 20 may use at least one of carrier aggregation (Carrier Aggregation (CA)) using a plurality of component carriers (Component Carrier (CC)) and Dual Connection (DC).

Each CC may be included in at least one of the first Frequency band (Frequency Range 1 (FR 1)) and the second Frequency band (Frequency Range 2 (FR 2))). The macrocell C1 may be included in the FR1 and the small cell C2 may be included in the FR 2. For example, FR1 may be a frequency band of 6GHz or less (lower than 6GHz (sub-6 GHz)), and FR2 may be a frequency band higher than 24GHz (above-24 GHz). The frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be a higher frequency band than FR 2.

The user terminal 20 may perform communication using at least one of time division duplex (Time Division Duplex (TDD)) and frequency division duplex (Frequency Division Duplex (FDD)) in each CC.

The plurality of base stations 10 may also be connected by wire (e.g., optical fiber based on a common public radio interface (Common Public Radio Interface (CPRI)), X2 interface, etc.) or wireless (e.g., NR communication). For example, when NR communication is utilized as a backhaul between the base stations 11 and 12, the base station 11 corresponding to a higher-level station may be referred to as an integrated access backhaul (Integrated Access Backhaul (IAB)) donor (donor), and the base station 12 corresponding to a relay station (relay) may be referred to as an IAB node.

The base station 10 may also be connected to the core network 30 via other base stations 10 or directly. The Core Network 30 may include at least one of an evolved packet Core (Evolved Packet Core (EPC)), a 5G Core Network (5 GCN), a next generation Core (Next Generation Core (NGC)), and the like, for example.

The user terminal 20 may be a terminal supporting at least one of communication schemes such as LTE, LTE-a, and 5G.

In the wireless communication system 1, a wireless access scheme based on orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing (OFDM)) may be used. For example, cyclic prefix OFDM (Cyclic Prefix OFDM (CP-OFDM)), discrete fourier transform spread OFDM (Discrete Fourier Transform Spread OFDM (DFT-s-OFDM)), orthogonal frequency division multiple access (Orthogonal Frequency Division Multiple Access (OFDMA)), single carrier frequency division multiple access (Single Carrier Frequency Division Multiple Access (SC-FDMA)), and the like may be used in at least one of Downlink (DL)) and Uplink (UL).

The radio access scheme may also be referred to as waveform (waveform). In the radio communication system 1, other radio access schemes (for example, other single carrier transmission schemes and other multi-carrier transmission schemes) may be used for the UL and DL radio access schemes.

As the downlink channel, a downlink shared channel (physical downlink shared channel (Physical Downlink Shared Channel (PDSCH))), a broadcast channel (physical broadcast channel (Physical Broadcast Channel (PBCH)))), a downlink control channel (physical downlink control channel (Physical Downlink Control Channel (PDCCH))), and the like shared by the user terminals 20 may be used in the wireless communication system 1.

As the uplink channel, an uplink shared channel (physical uplink shared channel (Physical Uplink Shared Channel (PUSCH))), an uplink control channel (physical uplink control channel (Physical Uplink Control Channel (PUCCH))), a random access channel (physical random access channel (Physical Random Access Channel (PRACH))), or the like shared by the user terminals 20 may be used in the wireless communication system 1.

User data, higher layer control information, system information blocks (System Information Block (SIBs)), and the like are transmitted through the PDSCH. User data, higher layer control information, etc. may also be transmitted through the PUSCH. In addition, a master information block (Master Information Block (MIB)) may also be transmitted through the PBCH.

Lower layer control information may also be transmitted through the PDCCH. The lower layer control information may include, for example, downlink control information (Downlink Control Information (DCI))) including scheduling information of at least one of PDSCH and PUSCH.

The DCI scheduling PDSCH may be referred to as DL allocation, DL DCI, or the like, and the DCI scheduling PUSCH may be referred to as UL grant, UL DCI, or the like. The PDSCH may be rewritten to DL data, and the PUSCH may be rewritten to UL data.

In the detection of PDCCH, a control resource set (COntrol REsource SET (CORESET)) and a search space (search space) may also be utilized. CORESET corresponds to searching for the resources of DCI. The search space corresponds to a search region of PDCCH candidates (PDCCH candidates) and a search method. A CORESET may also be associated with one or more search spaces. The UE may also monitor CORESET associated with a certain search space based on the search space settings.

One search space may also correspond to PDCCH candidates corresponding to one or more aggregation levels (aggregation Level). One or more search spaces may also be referred to as a set of search spaces. In addition, "search space", "search space set", "search space setting", "search space set setting", "CORESET setting", and the like of the present disclosure may also be rewritten with each other.

Uplink control information (Uplink Control Information (UCI)) including at least one of channel state information (Channel State Information (CSI)), transmission acknowledgement information (e.g., also referred to as hybrid automatic repeat request acknowledgement (Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK)), ACK/NACK, etc.), and scheduling request (Scheduling Request (SR)) may also be transmitted through the PUCCH. The random access preamble used to establish a connection with a cell may also be transmitted via the PRACH.

In addition, in the present disclosure, downlink, uplink, etc. may be expressed without "link". The present invention may be expressed without "Physical" at the beginning of each channel.

In the wireless communication system 1, a synchronization signal (Synchronization Signal (SS)), a downlink reference signal (Downlink Reference Signal (DL-RS)), and the like may be transmitted. As DL-RS, a Cell-specific reference signal (Cell-specific Reference Signal (CRS)), a channel state information reference signal (Channel State Information Reference Signal (CSI-RS)), a demodulation reference signal (DeModulation Reference Signal (DMRS)), a positioning reference signal (Positioning Reference Signal (PRS)), a phase tracking reference signal (Phase Tracking Reference Signal (PTRS)), and the like may be transmitted in the wireless communication system 1.

The synchronization signal may be at least one of a primary synchronization signal (Primary Synchronization Signal (PSS)) and a secondary synchronization signal (Secondary Synchronization Signal (SSS)), for example. The signal blocks including SS (PSS, SSs) and PBCH (and DMRS for PBCH) may also be referred to as SS/PBCH blocks, SS blocks (SSB)), or the like. In addition, SS, SSB, etc. may also be referred to as reference signals.

In the wireless communication system 1, as an uplink reference signal (Uplink Reference Signal (UL-RS)), a reference signal for measurement (sounding reference signal (Sounding Reference Signal (SRS))), a reference signal for Demodulation (DMRS), and the like may be transmitted. In addition, the DMRS may also be referred to as a user terminal specific reference signal (UE-specific Reference Signal).

(base station)

Fig. 19 is a diagram showing an example of a configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transmitting/receiving unit 120, a transmitting/receiving antenna 130, and a transmission path interface (transmission line interface (transmission line interface)) 140. The control unit 110, the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140 may be provided with one or more components.

In this example, the functional blocks of the characteristic part 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. A part of the processing of each unit described below may be omitted.

The control unit 110 performs control of the entire base station 10. The control unit 110 can be configured by a controller, a control circuit, or the like described based on common knowledge in the technical field of the present disclosure.

The control unit 110 may also control generation of signals, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission/reception, measurement, and the like using the transmission/reception unit 120, the transmission/reception antenna 130, and the transmission path interface 140. The control unit 110 may generate data, control information, a sequence (sequence), and the like transmitted as signals, and forward the generated data to the transmitting/receiving unit 120. The control unit 110 may perform call processing (setting, release, etc.) of the communication channel, state management of the base station 10, management of radio resources, and the like.

The transmitting/receiving unit 120 may include a baseband (baseband) unit 121, a Radio Frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may also include a transmission processing unit 1211 and a reception processing unit 1212. The transmitting/receiving unit 120 may be configured of a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter (phase shifter), a measurement circuit, a transmitting/receiving circuit, and the like, which are described based on common knowledge in the technical field of the present disclosure.

The transmitting/receiving unit 120 may be configured as an integral transmitting/receiving unit, or may be configured by a transmitting unit and a receiving unit. The transmission unit may be composed of the transmission processing unit 1211 and the RF unit 122. The receiving unit may be composed of a receiving processing unit 1212, an RF unit 122, and a measuring unit 123.

The transmitting/receiving antenna 130 may be constituted by an antenna described based on common knowledge in the technical field of the present disclosure, for example, an array antenna or the like.

The transmitting/receiving unit 120 may transmit the downlink channel, the synchronization signal, the downlink reference signal, and the like. The transmitting/receiving unit 120 may receive the uplink channel, the uplink reference signal, and the like.

The transmitting-receiving unit 120 may also form at least one of a transmit beam and a receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), and the like.

The transmission/reception section 120 (transmission processing section 1211) may perform processing of a packet data convergence protocol (Packet Data Convergence Protocol (PDCP)) layer, processing of a radio link control (Radio Link Control (RLC)) layer (for example, RLC retransmission control), processing of a medium access control (Medium Access Control (MAC)) layer (for example, HARQ retransmission control), and the like with respect to data, control information, and the like acquired from the control section 110, for example, to generate a bit sequence to be transmitted.

The transmission/reception section 120 (transmission processing section 1211) may perform transmission processing such as channel coding (error correction coding may be included), modulation, mapping, filter processing (filtering processing), discrete fourier transform (Discrete Fourier Transform (DFT)) processing (if necessary), inverse fast fourier transform (Inverse Fast Fourier Transform (IFFT)) processing, precoding, and digital-analog conversion on a bit string to be transmitted, and output a baseband signal.

The transmitting/receiving unit 120 (RF unit 122) may perform modulation, filter processing, amplification, etc. on the baseband signal in the radio frequency band, and transmit the signal in the radio frequency band via the transmitting/receiving antenna 130.

On the other hand, the transmitting/receiving unit 120 (RF unit 122) may amplify, filter-process, demodulate a signal in a radio frequency band received by the transmitting/receiving antenna 130, and the like.

The transmitting/receiving section 120 (reception processing section 1212) may apply an analog-to-digital conversion, a fast fourier transform (Fast Fourier Transform (FFT)) process, an inverse discrete fourier transform (Inverse Discrete Fourier Transform (IDFT)) process (if necessary), a filter process, demapping, demodulation, decoding (error correction decoding may be included), a MAC layer process, an RLC layer process, a PDCP layer process, and other reception processes to the acquired baseband signal, and acquire user data.

The transmitting-receiving unit 120 (measuring unit 123) may also perform measurements related to the received signals. For example, measurement section 123 may perform radio resource management (Radio Resource Management (RRM)) measurement, channel state information (Channel State Information (CSI)) measurement, and the like based on the received signal. Measurement section 123 may also measure received power (for example, reference signal received power (Reference Signal Received Power (RSRP))), received quality (for example, reference signal received quality (Reference Signal Received Quality (RSRQ)), signal-to-interference-plus-noise ratio (Signal to Interference plus Noise Ratio (SINR)), signal-to-noise ratio (Signal to Noise Ratio (SNR))), signal strength (for example, received signal strength indicator (Received Signal Strength Indicator (RSSI)), propagation path information (for example, CSI), and the like. The measurement results may also be output to the control unit 110.

The transmission path interface 140 may transmit and receive signals (backhaul signaling) to and from devices, other base stations 10, and the like included in the core network 30, or may acquire and transmit user data (user plane data), control plane data, and the like for the user terminal 20.

In addition, the transmitting unit and the receiving unit of the base station 10 in the present disclosure may be configured by at least one of the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140.

The transmitting/receiving unit 120 may transmit setting information (for example, a beamFailureRecoveryConfig information element) for detecting a predicted beam failure to the user terminal 20 based on a predicted radio link quality at a future time calculated from radio link qualities corresponding to one or more reference signals.

The transmitting and receiving unit 120 may also receive a random access channel (PRACH, random access preamble) for predicted beam failure recovery triggered based on the detection of the predicted beam failure from the user terminal 20.

The transmitting/receiving unit 120 may receive information on the prediction accuracy of the predicted radio link quality from the user terminal 20.

Further, the transmitting/receiving unit 120 may also receive an uplink shared channel (PUSCH) for predicted beam failure recovery triggered based on the detection of the predicted beam failure from the user terminal 20.

(user terminal)

Fig. 20 is a diagram showing an example of a configuration of a user terminal according to an embodiment. The user terminal 20 includes a control unit 210, a transmitting/receiving unit 220, and a transmitting/receiving antenna 230. The control unit 210, the transmitting/receiving unit 220, and the transmitting/receiving antenna 230 may be provided with one or more types.

In this example, the functional blocks of the characteristic parts in the present embodiment are mainly shown, and it is also conceivable that the user terminal 20 further has other functional blocks necessary for wireless communication. A part of the processing of each unit described below may be omitted.

The control unit 210 performs control of the entire user terminal 20. The control unit 210 can be configured by a controller, a control circuit, or the like described based on common knowledge in the technical field of the present disclosure.

The control unit 210 may also control the generation of signals, mapping, etc. The control unit 210 may control transmission/reception, measurement, and the like using the transmission/reception unit 220 and the transmission/reception antenna 230. The control unit 210 may generate data, control information, a sequence, and the like transmitted as signals, and forward the generated data to the transmitting/receiving unit 220.

The transceiver unit 220 may also include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transmitting/receiving unit 220 may be configured of a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmitting/receiving circuit, and the like, which are described based on common knowledge in the technical field of the present disclosure.

The transmitting/receiving unit 220 may be configured as an integral transmitting/receiving unit, or may be configured by a transmitting unit and a receiving unit. The transmission means may be constituted by the transmission processing means 2211 and the RF means 222. The receiving unit may be composed of a receiving processing unit 2212, an RF unit 222, and a measuring unit 223.

The transmitting/receiving antenna 230 may be constituted by an antenna described based on common knowledge in the technical field of the present disclosure, for example, an array antenna or the like.

The transceiver unit 220 may also receive the above-described downlink channel, synchronization signal, downlink reference signal, and the like. The transceiver unit 220 may transmit the uplink channel, the uplink reference signal, and the like.

The transmitting-receiving unit 220 may also form at least one of a transmit beam and a receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), and the like.

The transmission/reception section 220 (transmission processing section 2211) may perform, for example, PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control) and the like with respect to the data, control information and the like acquired from the control section 210, and generate a bit sequence to be transmitted.

The transmission/reception section 220 (transmission processing section 2211) may perform transmission processing such as channel coding (error correction coding may be included), modulation, mapping, filter processing, DFT processing (as needed), IFFT processing, precoding, digital-to-analog conversion, and the like for a bit string to be transmitted, and output a baseband signal.

Further, whether to apply DFT processing may be based on the setting of transform precoding. For a certain channel (e.g., PUSCH), when transform precoding is valid (enabled), the transmission/reception section 220 (transmission processing section 2211) may perform DFT processing as the transmission processing for transmitting the channel using a DFT-s-OFDM waveform, and if not, the transmission/reception section 220 (transmission processing section 2211) may not perform DFT processing as the transmission processing.

The transmitting/receiving unit 220 (RF unit 222) may perform modulation, filter processing, amplification, etc. for the baseband signal in the radio frequency band, and transmit the signal in the radio frequency band via the transmitting/receiving antenna 230.

On the other hand, the transmitting/receiving unit 220 (RF unit 222) may amplify, filter-process, demodulate a baseband signal, and the like, with respect to a signal in a radio frequency band received through the transmitting/receiving antenna 230.

The transmitting/receiving section 220 (reception processing section 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filter processing, demapping, demodulation, decoding (error correction decoding may be included), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data.

The transceiver unit 220 (measurement unit 223) may also perform measurements related to the received signals. For example, the measurement unit 223 may also perform RRM measurement, CSI measurement, and the like based on the received signal. The measurement unit 223 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), etc. The measurement results may also be output to the control unit 210.

In addition, the transmitting unit and the receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting/receiving unit 220, the transmitting/receiving antenna 230, and the transmission path interface 240.

The transmitting/receiving unit 220 may calculate the radio link quality corresponding to one or more reference signals.

The control unit 210 may also detect a predicted beam failure based on a predicted radio link quality at a future time calculated from the radio link quality.

The control unit 210 may also envisage that the future times in the timer start are the same, so as to detect the predicted beam failure.

The control unit 210 may also perform control as follows: a random access channel is transmitted for predicted beam failure recovery triggered based on the detection of the predicted beam failure.

The control unit 210 may also send information about the time at which the predicted beam failure recovery was implemented.

Further, the transmitting/receiving unit 220 may transmit information on the prediction accuracy of the predicted radio link quality.

The transmitting-receiving unit 220 may also receive information about whether a predicted beam failure recovery triggered based on the detection of the predicted beam failure is accepted.

The control unit 210 may also update the quasi-addressing or spatial relationship with respect to a specific signal after receiving information about whether the predicted beam failure recovery is accepted.

Further, the transmitting and receiving unit 220 may also transmit an uplink shared channel (PUSCH) for predicted beam failure recovery triggered based on the detection of the predicted beam failure.

The transmitting/receiving unit 220 may also transmit a medium access Control Element (MAC (Medium Access Control) Control Element (CE)) for the predicted beam failure recovery in the uplink shared channel.

The MAC CE may contain information about the time when the predicted beam failure occurred, and may also contain information indicating whether the predicted beam failure recovery or beam failure recovery occurred.

(hardware construction)

The block diagrams used in the description of the above embodiments show blocks of functional units. These functional blocks (structural units) are implemented by any combination of at least one of hardware and software. The implementation method of each functional block is not particularly limited. That is, each functional block may be realized by one device physically or logically combined, or two or more devices physically or logically separated may be directly or indirectly connected (for example, by a wire, a wireless, or the like) and realized by these plural devices. The functional blocks may also be implemented by combining the above-described device or devices with software.

Here, the functions include, but are not limited to, judgment, decision, judgment, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, establishment, comparison, assumption, expectation, view, broadcast (broadcasting), notification (notification), communication (communication), forwarding (forwarding), configuration (configuration), reconfiguration (reconfiguration), allocation (mapping), assignment (allocation), and the like. For example, a functional block (structural unit) that realizes the transmission function may also be referred to as a transmission unit (transmitting unit), a transmitter (transmitter), or the like. As described above, the implementation method is not particularly limited.

For example, a base station, a user terminal, and the like in one embodiment of the present disclosure may also function as a computer that performs the processing of the wireless communication method of the present disclosure. Fig. 21 is a diagram showing an example of a hardware configuration 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 addition, in this disclosure, terms of apparatus, circuit, device, section, unit, and the like can be rewritten with each other. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to not include a part of the devices.

For example, the processor 1001 is shown as only one, but there may be multiple processors. Further, the processing may be performed by one processor, or the processing may be performed by two or more processors simultaneously, sequentially, or by other means. The processor 1001 may be realized by one or more chips.

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

The processor 1001, for example, causes an operating system to operate to control the entire computer. The processor 1001 may be configured by a central processing unit (Central Processing Unit (CPU)) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like. For example, at least a part of the control unit 110 (210), the transmitting/receiving unit 120 (220), and the like described above may be implemented by the processor 1001.

Further, the processor 1001 reads out a program (program code), a software module, data, or the like from at least one of the memory 1003 and the communication device 1004 to the memory 1002, and executes various processes according to them. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment can be used. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and operated in the processor 1001, and the same may be implemented for other functional blocks.

The Memory 1002 may be a computer-readable recording medium, and may be constituted by at least one of a Read Only Memory (ROM), an erasable programmable Read Only Memory (Erasable Programmable ROM (EPROM)), an electrically erasable programmable Read Only Memory (Electrically EPROM (EEPROM)), a random access Memory (Random Access Memory (RAM)), and other suitable storage media, for example. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage), or the like. The memory 1002 can store programs (program codes), software modules, and the like executable to implement a wireless communication method according to an embodiment of the present disclosure.

The storage 1003 may also be a computer-readable recording medium, for example, constituted by at least one of a flexible disk (flexible Disc), a soft (registered trademark) disk, an magneto-optical disk (for example, a Compact Disc read only memory (CD-ROM), etc.), a digital versatile Disc, a Blu-ray (registered trademark) disk, a removable magnetic disk (removables), a hard disk drive, a smart card, a flash memory device (for example, a card, a stick, a key drive), a magnetic stripe (strip), a database, a server, and other suitable storage medium. The storage 1003 may also be referred to as secondary storage.

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, for example. In order to realize at least one of frequency division duplexing (Frequency Division Duplex (FDD)) and time division duplexing (Time Division Duplex (TDD)), the communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like. For example, the transmitting/receiving unit 120 (220), the transmitting/receiving antenna 130 (230), and the like described above may be implemented by the communication device 1004. The transmitting/receiving unit 120 (220) may be implemented by physically or logically separating the transmitting unit 120a (220 a) and the receiving unit 120b (220 b).

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

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

The base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (Digital Signal Processor (DSP)), an application specific integrated circuit (Application Specific Integrated Circuit (ASIC)), a programmable logic device (Programmable Logic Device (PLD)), and a field programmable gate array (Field Programmable Gate Array (FPGA)), or may be configured to implement a part or all of the functional blocks by using the hardware. For example, the processor 1001 may also be implemented using at least one of these hardware.

(modification)

In addition, with respect to terms described in the present disclosure and terms required for understanding the present disclosure, terms having the same or similar meanings may be substituted. For example, channels, symbols, and signals (signals or signaling) may also be interchanged. In addition, the signal may also be a message. The Reference Signal (RS) can also be simply referred to as RS, and may also be referred to as Pilot (Pilot), pilot Signal, or the like, depending on the standard applied. In addition, the component carrier (Component Carrier (CC)) may also be referred to as a cell, a frequency carrier, a carrier frequency, or the like.

A radio frame may also consist 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, a subframe may also be formed of one or more slots in the time domain. The subframes may also be a fixed length of time (e.g., 1 ms) independent of the parameter set (numerology).

Here, the parameter set may also be a communication parameter applied in at least one of transmission and reception of a certain signal or channel. For example, the parameter set may also represent at least one of a subcarrier spacing (SubCarrier Spacing (SCS)), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (Transmission Time Interval (TTI)), a number of symbols per TTI, a radio frame structure, a specific filter process performed by a transceiver in a frequency domain, a specific windowing (windowing) process performed by a transceiver in a time domain, and the like.

A slot may also be formed in the time domain from one or more symbols, orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing (OFDM)) symbols, single carrier frequency division multiple access (Single Carrier Frequency Division Multiple Access (SC-FDMA)) symbols, and so on. Furthermore, the time slots may also be time units based on parameter sets.

The time slot may also contain a plurality of mini-slots. Each mini-slot may also be formed of one or more symbols in the time domain. In addition, the mini-slot may also be referred to as a sub-slot. Mini-slots may also be made up of a fewer number of symbols than slots. PDSCH (or PUSCH) transmitted in a larger time unit than the 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 each represent a unit of time when a signal is transmitted. The radio frames, subframes, slots, mini-slots, and symbols may also use other designations that each corresponds to. In addition, the frame, subframe, slot, mini-slot, symbol, and the like units in the present disclosure may also be rewritten with each other.

For example, one subframe may also be referred to as a TTI, a plurality of consecutive subframes may also be referred to as a TTI, and one slot or one mini-slot may also be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the conventional LTE, may be a period (for example, 1 to 13 symbols) shorter than 1ms, or may be a period longer than 1 ms. The unit indicating the TTI may be referred to as a slot, a mini-slot, or the like, instead of a subframe.

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

The TTI may be a transmission time unit of a data packet (transport block), a code block, a codeword, or the like subjected to channel coding, or may be a processing unit such as scheduling or link adaptation. In addition, when a TTI is given, a time interval (e.g., the number of symbols) in which a transport block, a code block, a codeword, etc. are actually mapped may be shorter than the TTI.

In addition, in the case where one slot or one mini-slot is referred to as a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may also be the minimum time unit of scheduling. In addition, the number of slots (mini-slots) constituting the minimum time unit of the schedule can also be controlled.

A TTI having a time length of 1ms may also be referred to as a normal TTI (TTI in 3gpp rel.8-12), a standard TTI, a long TTI, a normal subframe, a standard subframe, a long subframe, a slot, etc. A TTI that is shorter than a normal TTI may also be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini-slot, a sub-slot, a slot, etc.

In addition, a long TTI (e.g., normal TTI, subframe, etc.) may be rewritten to a TTI having a time length exceeding 1ms, and a short TTI (e.g., shortened TTI, etc.) may be rewritten to a TTI having a TTI length less than the long TTI and a TTI length of 1ms or more.

A Resource Block (RB) is a Resource allocation unit of a time domain and a frequency domain, and may include one or a plurality of consecutive subcarriers (subcarriers) in the frequency domain. The number of subcarriers included in the 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.

Further, the RB may also contain one or more symbols in the time domain, and may be one slot, one mini-slot, one subframe, or one TTI in length. One TTI, one subframe, etc. may also be respectively composed of one or more resource blocks.

In addition, one or more RBs may also be referred to as Physical Resource Blocks (PRBs), subcarrier groups (SCGs), resource element groups (Resource Element Group (REGs)), PRB pairs, RB peering.

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

A Bandwidth Part (BWP) (which may also be referred to as a partial Bandwidth, etc.) may also represent a subset of consecutive common RBs (common resource blocks (common resource blocks)) for a certain parameter set in a certain carrier. Here, the common RB may also be determined by an index of the RB with reference to the common reference point of the carrier. PRBs may be defined in a BWP and numbered in the BWP.

The BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). For a UE, one or more BWP may also be set in one carrier.

At least 1 of the set BWP may also be activated, and the UE may not contemplate: the specific signal/channel is transmitted and received outside the activated BWP. In addition, "cell", "carrier", etc. in the present disclosure may also be rewritten as "BWP".

The above-described configurations of radio frames, subframes, slots, mini slots, symbols, and the like are merely examples. For example, the number of subframes included in a 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 the like can be variously changed.

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

In the present disclosure, the names used for parameters and the like are not restrictive names in all aspects. Further, the mathematical expression or the like using these parameters may also be different from that explicitly disclosed in the present disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not limiting names in all respects.

Information, signals, etc. described in this disclosure may also be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips (chips), and the like 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.

Further, information, signals, etc. can be output in at least one of the following directions: from higher layer (upper layer) to lower layer (lower layer), and from lower layer to higher layer. Information, signals, etc. may also be input and output via a plurality of network nodes.

The input/output information, signals, and the like may be stored in a specific location (for example, a memory), or may be managed by a management table. The input and output information, signals, etc. may be overwritten, updated, or added. The outputted information, signals, etc. may also be deleted. The input information, signals, etc. may also be transmitted to other devices.

The notification of information is not limited to the embodiment described in the present disclosure, but may be performed by other methods. For example, notification of information in the present disclosure may also be implemented by physical layer signaling (e.g., downlink control information (Downlink Control Information (DCI))), uplink control information (Uplink Control Information (UCI)))), higher layer signaling (e.g., radio resource control (Radio Resource Control (RRC)) signaling, broadcast information (master information block (Master Information Block (MIB)), system information block (System Information Block (SIB)) or the like), medium access control (Medium Access Control (MAC)) signaling), other signals, or a combination thereof.

The physical Layer signaling may be referred to as Layer 1/Layer 2 (L1/L2)) control information (L1/L2 control signal), L1 control information (L1 control signal), or the like. The RRC signaling may be called an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration)) message, or the like. The MAC signaling may be notified using, for example, a MAC control element (MAC Control Element (CE)).

Note that the notification of specific information (for example, notification of "X") is not limited to explicit notification, and may be performed implicitly (for example, by notification of no specific information or notification of other information).

The determination may be performed by a value (0 or 1) represented by one bit, a true or false value (boolean) represented by true or false, or a comparison of values (e.g., with a specific value).

Software, whether referred to as software (firmware), middleware (middleware-software), microcode (micro-code), hardware description language, or by other names, should be construed broadly to mean instructions, instruction sets, codes (codes), code segments (code fragments), program codes (program codes), programs (programs), subroutines (sub-programs), software modules (software modules), applications (applications), software applications (software application), software packages (software packages), routines (routines), subroutines (sub-routines), objects (objects), executable files, threads of execution, procedures, functions, and the like.

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

The terms "system" and "network" as used in this disclosure can be used interchangeably. "network" may also mean a device (e.g., a base station) included in a network.

In the present disclosure, terms such as "precoding", "precoder", "weight", "Quasi Co-Location", "transmission setting instruction state (Transmission Configuration Indication state (TCI state))", "spatial relationship", "spatial domain filter (spatial domain filter)", "transmission power", "phase rotation", "antenna port group", "layer number", "rank", "resource set", "resource group", "beam width", "beam angle", "antenna element", "panel", and the like can be used interchangeably.

In the present disclosure, terms such as "Base Station (BS))", "radio Base Station", "fixed Station", "NodeB", "eNB (eNodeB)", "gNB (gndeb)", "access Point", "Transmission Point (Transmission Point (TP))", "Reception Point (RP))", "Transmission Reception Point (Transmission/Reception Point (TRP)", "panel", "cell", "sector", "cell group", "carrier", "component carrier", and the like can be used interchangeably. There are also cases where the base station is referred to by terms of a macrocell, a small cell, a femtocell, a picocell, and the like.

The base station can accommodate one or more (e.g., three) cells. In the case of a base station accommodating a plurality of cells, the coverage area of the base station can be divided into a plurality of smaller areas, each of which can also provide communication services through a base station subsystem, such as a small base station for indoor use (remote radio head (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a portion or the entirety of the coverage area of at least one of the base station and the base station subsystem that is in communication service within that coverage area.

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

There are also situations where a mobile station is referred to by 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, hand-held communicator (hand set), user agent, mobile client, or a number of other suitable terms.

At least one of the base station and the mobile station may also be referred to as a transmitting apparatus, a receiving apparatus, a wireless communication apparatus, or the like. At least one of the base station and the mobile station may be a device mounted on a mobile body, or the like. The mobile body may be a vehicle (e.g., a vehicle, an airplane, etc.), a mobile body that moves unmanned (e.g., an unmanned aerial vehicle (clone), an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station includes a device that does not necessarily move when performing a communication operation. For example, at least one of the base station and the mobile station may be an internet of things (Internet of Things (IoT)) device such as a sensor.

In addition, the base station in the present disclosure may also be rewritten as a user terminal. For example, the various aspects/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, may also be referred to as Device-to-Device (D2D)), vehicle-to-evaluation (V2X), or the like. In this case, the user terminal 20 may have the functions of the base station 10 described above. The language such as "uplink" and "downlink" may be rewritten to a language (e.g., "side") corresponding to the communication between terminals. For example, the uplink channel, the downlink channel, and the like may be rewritten as side channels.

Likewise, the user terminal in the present disclosure may also be rewritten as 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, the operation performed by the base station may be performed by an upper node (upper node) according to circumstances. Obviously, in a network comprising one or more network nodes (network nodes) with base stations, various operations performed for communication with a terminal may be performed by a base station, one or more network nodes other than a base station (e.g. considering a mobility management entity (Mobility Management Entity (MME)), a Serving-Gateway (S-GW)), etc., but not limited thereto, or a combination thereof.

The embodiments described in the present disclosure may be used alone, in combination, or switched depending on the execution. The processing procedure, the sequence, the flow chart, and the like of each embodiment/mode described in the present disclosure may be changed as long as they are not contradictory. For example, for the methods described in this disclosure, elements of the various steps are presented using the illustrated order, but are not limited to the particular order presented.

The various modes/embodiments described in the present disclosure can also be applied to long term evolution (Long Term Evolution (LTE)), LTE-Advanced (LTE-a), LTE-Beyond (LTE-B), upper 3G, IMT-Advanced, fourth-generation mobile communication system (4 th generation mobile communication system (4G)), fifth-generation mobile communication system (5 th generation mobile communication system (5G)), sixth-generation mobile communication system (6 th generation mobile communication system (6G)), x-th-generation mobile communication system (xth generation mobile communication system (xG)) (xG (x is, for example, an integer, a decimal)), future wireless access (Future Radio Access (FRA)), new wireless access technology (New-Radio Access Technology (RAT)), new wireless (New Radio (NR)), new Radio access (NX), new-generation wireless access (Future generation Radio access (FX)), global system for mobile communication (Global System for Mobile communications (GSM (registered trademark)), 2000, ultra mobile broadband (Ultra Mobile Broadband (UMB)), IEEE 802.11 (IEEE-Fi (registered trademark) 802.16 (Wi) and (registered trademark), bluetooth (20) and other suitable methods based on them, and the like, and the Ultra-WideBand (UWB) can be obtained, multiple systems may also be applied in combination (e.g., LTE or LTE-a, in combination with 5G, etc.).

The term "based on" as used in the present disclosure is not intended to mean "based only on" unless specifically written otherwise. In other words, the recitation of "based on" means "based only on" and "based at least on" both.

Any reference to elements using references in this specification to "first," "second," etc. does not entirely limit the amount or order of such elements. These designations can be used throughout this specification as a convenient method of distinguishing between two or more elements. Thus, reference to a first and second element does not mean that only two elements can be employed or that in some form the first element must precede the second element.

The term "determining" used in the present disclosure may include various actions. For example, the "judgment (decision)" may be a case where judgment (decision), calculation (calculation), processing (processing), derivation (development), investigation (investigation), search (lookup), search, inquiry (search in a table, database, or other data structure), confirmation (evaluation), or the like is regarded as "judgment (decision)".

The "determination (decision)" may be a case where reception (e.g., reception of information), transmission (e.g., transmission of information), input (input), output (output), access (processing) (e.g., access to data in a memory), or the like is regarded as "determination (decision)".

The "judgment (decision)" may be a case where resolution (resolution), selection (selection), selection (setting), establishment (establishment), comparison (comparison), or the like is regarded as "judgment (decision)". That is, the "judgment (decision)" may be a case where some actions are regarded as "judgment (decision)" to be performed.

The "judgment (decision)" may be rewritten as "assumption", "expectation", "consider", or the like.

The "maximum transmission power" described in the present disclosure may be the maximum value of transmission power, the nominal maximum transmission power (nominal UE maximum transmission power (the nominal UE maximum transmit power)), or the nominal maximum transmission power (nominal UE maximum transmission power (the rated UE maximum transmit power)).

The terms "connected", "coupled", or all variations thereof as used in this disclosure mean all connections or couplings, either direct or indirect, between two or more elements thereof, and can include the case where one or more intervening elements are present between two elements that are "connected" or "coupled" to each other. The bonding or connection between elements may be physical, logical, or a combination thereof. For example, "connection" may also be rewritten as "access".

In the present disclosure, where two elements are connected, it is contemplated that more than one wire, cable, printed electrical connection, etc. can be used, and electromagnetic energy, etc. having wavelengths in the wireless frequency domain, the microwave region, the optical (both visible and invisible) region, etc. can be used as several non-limiting and non-inclusive examples, to be "connected" or "joined" to each other.

In the present disclosure, the term "a is different from B" may also mean that "a is different from B". In addition, the term may also mean that "A and B are each different from C". Terms such as "separate," coupled, "and the like may also be construed in the same manner as" different.

In the case where "including", "containing", and variations thereof are used in the present disclosure, these terms are meant to be inclusive in the same sense as the term "comprising". Further, the term "or" as used in this disclosure does not mean exclusive or.

In the present disclosure, for example, in the case where an article is appended by translation as in a, an, and the in english, the present disclosure may also include the case where a noun following the article is in plural form.

While the invention according to the present disclosure has been described in detail, it is obvious 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 variation without departing from the spirit and scope of the invention defined based on the description of the claims. Accordingly, the description of the present disclosure is for illustrative purposes and is not intended to limit the invention in any way.

Claims (6)

1. A terminal, comprising:

a receiving unit that calculates a radio link quality corresponding to one or more reference signals;

a control unit configured to detect a predicted beam failure based on a predicted radio link quality at a future time calculated from the radio link quality; and

and a transmission unit configured to transmit an uplink shared channel for predicted beam failure recovery triggered based on the detection of the predicted beam failure.

2. The terminal according to claim 1,

the transmitting unit transmits a medium access control element (MAC (Medium Access Control) CE (Control CE)) for the predicted beam failure recovery in the uplink shared channel.

3. The terminal according to claim 2,

the MAC CE contains information about the time at which the predicted beam failure occurred.

4. The terminal according to claim 2 or claim 3,

the MAC CE contains information indicating whether the predicted beam failure recovery or beam failure recovery.

5. A wireless communication method for a terminal, the wireless communication method having:

a step of calculating radio link quality corresponding to one or more reference signals;

a step of detecting a predicted beam failure based on a predicted radio link quality at a future time calculated from the radio link quality; and

and transmitting an uplink shared channel for predicted beam failure recovery triggered based on the detection of the predicted beam failure.

6. A base station, comprising:

a transmission unit configured to transmit setting information for detecting a predicted beam failure to a terminal based on a predicted radio link quality at a future time calculated from radio link qualities corresponding to one or more reference signals; and

and a receiving unit that receives, from the terminal, an uplink shared channel for predicted beam failure recovery triggered based on the detection of the predicted beam failure.