TERMINAL, RADIO COMMUNICATION METHOD, AND BASE STATION

A terminal according to one aspect of the present disclosure includes a receiving section that receives information indicating two transmission configuration indication (TCI) states for a physical downlink shared channel (PDSCH), and a control section that does not apply a first quasi co-location (QCL) parameter in a plurality of QCL parameters included in a specific TCI state in the two TCI states to reception of the PDSCH, and applies a second QCL parameter other than the first QCL parameter in the plurality of QCL parameters to the reception of the PDSCH. According to one aspect of the present disclosure, downlink signals from a plurality of transmission points can be appropriately received.

TECHNICAL FIELD

BACKGROUND ART

Successor systems of LTE (for example, also referred to as “5th generation mobile communication system (5G),” “5G+(plus),” “6th generation mobile communication system (6G),” “New Radio (NR),” “3GPP Rel. 15 (or later versions),” and so on) are also under study.

CITATION LIST

SUMMARY OF INVENTION

Technical Problem

In future radio communication systems (for example, NR), in order to implement radio communication in a moving object (for example, a train or the like) that moves at a high speed, using beams transmitted from transmission points (for example, Remote Radio Heads (RRHs)) installed in a path of the moving object is assumed.

However, how a terminal receives downlink signals transmitted from a plurality of transmission points has not yet been fully studied. Unless such operations are clarified, reduction of throughput and the like may be caused.

In view of this, the present disclosure has one object to provide a terminal, a radio communication method, and a base station that appropriately receive downlink signals from a plurality of transmission points.

Solution to Problem

A terminal according to one aspect of the present disclosure includes a receiving section that receives information indicating two transmission configuration indication (TCI) states for a physical downlink shared channel (PDSCH), and a control section that does not apply a first quasi co-location (QCL) parameter in a plurality of QCL parameters included in a specific TCI state in the two TCI states to reception of the PDSCH, and applies a second QCL parameter other than the first QCL parameter in the plurality of QCL parameters to the reception of the PDSCH.

Advantageous Effects of Invention

According to one aspect of the present disclosure, downlink signals from a plurality of transmission points can be appropriately received.

DESCRIPTION OF EMBODIMENTS

For NR, control of reception processing (for example, at least one of reception, demapping, demodulation, and decoding) and transmission processing (for example, at least one of transmission, mapping, precoding, modulation, and coding) in a UE regarding at least one of a signal and a channel (which is expressed as a signal/channel) based on a transmission configuration indication state (TCI state) is under study.

The TCI state may be a state applied to a downlink signal/channel. A state that corresponds to the TCI state applied to an uplink signal/channel may be expressed as spatial relation.

The TCI state is information related to quasi-co-location (QCL) of the signal/channel, and may be referred to as a spatial reception parameter, spatial relation information, or the like. The TCI state may be configured for the UE for each channel or for each signal.

QCL is an indicator indicating statistical properties of the signal/channel. For example, when a certain signal/channel and another signal/channel are in a relationship of QCL, it may be indicated that it is assumable that at least one of Doppler shift, a Doppler spread, an average delay, a delay spread, and a spatial parameter (for example, a spatial reception parameter (spatial Rx parameter)) is the same (the relationship of QCL is satisfied in at least one of these) between such a plurality of different signals/channels.

Note that the spatial reception parameter may correspond to a receive beam of the UE (for example, a receive analog beam), and the beam may be identified based on spatial QCL. The QCL (or at least one element in the relationship of QCL) in the present disclosure may be interpreted as sQCL (spatial QCL).

For the QCL, a plurality of types (QCL types) may be defined. For example, four QCL types A to D may be provided, which have different parameter(s) (or parameter set (s)) that can be assumed to be the same, and such parameter (s) (which may be referred to as QCL parameter (s)) are described below:QCL type A (QCL-A): Doppler shift, Doppler spread, average delay, and delay spreadQCL type B (QCL-B): Doppler shift and Doppler spreadQCL type C (QCL-C): Doppler shift and average delayQCL type D (QCL-D): Spatial reception parameter

A case that the UE assumes that a certain control resource set (CORESET), channel, or reference signal is in a relationship of specific QCL (for example, QCL type D) with another CORESET, channel, or reference signal may be referred to as QCL assumption.

The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) of the signal/channel, based on the TCI state or the QCL assumption of the signal/channel.

The TCI state may be, for example, information related to QCL between a channel as a target (in other words, a reference signal (RS) for the channel) and another signal (for example, another RS). The TCI state may be configured (indicated) by higher layer signaling or physical layer signaling, or a combination of these.

The physical layer signaling may be, for example, downlink control information (DCI).

A channel for which the TCI state or spatial relation is configured (specified) may be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

The RS to have a QCL relationship with the channel may be, for example, at least one of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a reference signal for measurement (Sounding Reference Signal (SRS)), a CSI-RS for tracking (also referred to as a Tracking Reference Signal (TRS)), and a reference signal for QCL detection (also referred to as a QRS).

The SSB is a signal block including at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (Physical Broadcast Channel (PBCH)). The SSB may be referred to as an SS/PBCH block.

An RS of QCL type X in a TCI state may mean an RS to have a relationship of QCL type X with (a DMRS for) a certain channel/signal, and this RS may be referred to as a QCL source of QCL type X in the TCI state.

In Rel. 16, the PDSCH may be scheduled with DCI having a TCI field. The TCI state for the PDSCH is indicated by the TCI field. The TCI field of DCI format 1-1 has 3 bits, and the TCI field of DCI format 1-2 has up to 3 bits.

In an RRC connected mode, when information of the TCI in first DCI (a higher layer parameter tci-PresentInDCI) is set to “enabled” for the CORESET to schedule the PDSCH, the UE assumes that the TCI field is present in DCI format 1_1 of the PDCCH to be transmitted in the CORESET.

When information of the TCI in second DCI (a higher layer parameter tci-PresentInDCI-1-2) for the CORESET to schedule the PDSCH is configured for the UE, the UE assumes that the TCI field having a DCI field size indicated by the information of the TCI in the second DCI is present in DCI format 1_2 of the PDSCH to be transmitted in the CORESET.

In Rel. 16, the PDSCH may be scheduled with DCI not having a TCI field. The DCI format of the DCI may be DCI format 1_0, or DCI format 1_1/1_2 in a case where the information of the TCI in the DCI (the higher layer parameter tci-PresentInDCI or tci-PresentInDCI-1-2) is not configured (to be enabled). When the PDSCH is scheduled with the DCI not having a TCI field, and a time offset between reception of DL DCI (DCI (scheduling DCI) to schedule the PDSCH) and a corresponding PDSCH (PDSCH scheduled by the DCI) is equal to or more than a threshold value (timeDurationForQCL), the UE assumes that the TCI state or the QCL assumption for the PDSCH is the same as the TCI state or the QCL assumption of the CORESET (for example, the scheduling DCI).

In the RRC connected mode, in both a case where information of the TCI in the DCI (the higher layer parameters tci-PresentInDCI and tci-PresentInDCI-1-2) is set to “enabled” and a case where the information of the TCI in the DCI is not configured, when a time offset between reception of DL DCI (DCI to schedule the PDSCH) and a corresponding PDSCH (PDSCH scheduled by the DCI) is less than the threshold value (timeDurationForQCL) (application condition, first condition), and in a case of non-cross carrier scheduling, a TCI state (default TCI state) for the PDSCH may be a TCI state with the lowest CORESET ID in the latest slot in an active DL BWP for that CC (for a specific UL signal). In cases other than the case, the TCI state (default TCI state) for the PDSCH may be a TCI state with the lowest TCI state ID of a PDSCH in an active DL BWP for a scheduled CC.

In Rel. 15, individual MAC CEs, that are a MAC CE for PUCCH spatial relation activation/deactivation and a MAC CE for SRS spatial relation activation/deactivation, are necessary. A PUSCH spatial relation follows the SRS spatial relation.

In Rel. 16, at least one of the MAC CE for PUCCH spatial relation activation/deactivation and the MAC CE for SRS spatial relation activation/deactivation need not be used.

If both a spatial relation and a PL-RS for a PUCCH are not configured in FR2 (application condition, second condition), default assumption for the spatial relation and PL-RS (default spatial relation and default PL-RS) is applied to the PUCCH. If both a spatial relation and a PL-RS for an SRS (SRS resource for the SRS or SRS resource corresponding to SRI in DCI format 0_1 to schedule a PUSCH) are not configured in FR2 (application condition, second condition), default assumption for the spatial relation and PL-RS (default spatial relation and default PL-RS) is applied to the PUSCH scheduled by DCI format 0_1, and the SRS.

If a CORESET is configured in an active DL BWP on that CC (application condition), the default spatial relation and default PL-RS may be a TCI state or QCL assumption for a CORESET having the lowest CORESET ID in the active DL BWP. If a CORESET is not configured in the active DL BWP on that CC, the default spatial relation and default PL-RS may be an active TCI state having the lowest ID for a PDSCH in the active DL BWP.

In Rel. 15, a spatial relation for a PUSCH scheduled by DCI format 0_0 follows a spatial relation for a PUCCH resource having the lowest PUCCH resource ID, out of active spatial relations for PUCCHs on the same CC. A network needs to update PUCCH spatial relations on all SCells even when the PUCCH is not transmitted on the SCell.

In Rel. 16, PUCCH configuration for the PUSCH scheduled by DCI format 0_0 is unnecessary. When an active PUCCH spatial relation or a PUCCH resource for the PUSCH scheduled by DCI format 0_0 is absent on an active UL BWP in that CC (application condition, second condition), the default spatial relation and default PL-RS are applied to the PUSCH.

A condition for application of the default spatial relation/default PL-RS for the SRS may include a case that an information element for enabling a default beam pathloss for the SRS (higher layer parameter enableDefaultBeamPlForSRS) is set to “enabled.” A condition for application of the default spatial relation/default PL-RS for the PUCCH may include a case that an information element for enabling a default beam pathloss for the PUCCH (higher layer parameter enableDefaultBeamPlForPUCCH) is set to “enabled.” A condition for application of the default spatial relation/default PL-RS for the PUSCH scheduled by DCI format 0_0 may include a case that an information element for enabling a default beam pathloss for the PUSCH scheduled by DCI format 0_0 (higher layer parameter enableDefaultBeamPlForPUSCH0_0) is set to “enabled.”

The above-described threshold value may be referred to as a time length (time duration) for QCL, “timeDurationForQCL,” “Threshold,” “Threshold for offset between a DCI indicating a TCI state and a PDSCH scheduled by the DCI,” “Threshold-Sched-Offset,” a schedule offset threshold value, a scheduling offset threshold value, or the like.

When an offset between reception of DL DCI and the PDSCH corresponding thereto is less than the threshold value timeDurationForQCL, at least one TCI state configured for the serving cell of the scheduled PDSCH includes “QCL type D”, the UE is configured with a parameter for enabling two default TCIs (enableTwoDefaultTCIStates-r16), and at least one TCI codepoint indicates two TCI states, the UE assumes that a DMRS port of a PDSCH or PDSCH transmission occasion of the serving cell is quasi co-located with an RS related to a QCL parameter associated with two TCI states corresponding to the lowest codepoint out of the TCI codepoints including two different TCI states. The parameter for enabling two default TCIs indicates that operations of Rel. 16 for two default TCI states for the PDSCH when at least one TCI codepoint is mapped to two TCI states are enabled.

According to a unified TCI framework, UL and DL channels can be controlled by a common framework. Instead of defining a TCI state or a spatial relation for each channel in a manner similar to that of Rel. 15, the unified TCI framework may indicate a common beam (common TCI state) and apply the common beam to all UL and DL channels, or may apply a UL common beam to all UL channels and apply a DL common beam to all DL channels.

One common beam for both DL and UL or a DL common beam and a UL common beam (two common beams in total) are under study.

The UE may assume the same TCI state (joint TCI state, joint TCI pool, joint common TCI pool, joint TCI state set) for the UL and the DL. The UE may assume different TCI states (separate TCI states, separate TCI pools, a UL separate TCI pool and a DL separate TCI pool, separate common TCI pools, a UL common TCI pool and a DL common TCI pool) for the respective UL and DL.

Default beams for the UL and DL may be unified by MAC CE-based beam management (MAC CE-level beam indication). The default beams may be unified with a default UL beam (spatial relation) by updating a default TCI state for the PDSCH.

A common beam/unified TCI state may be indicated from the same TCI pool for both of the UL and the DL (joint common TCI pool, joint TCI pool, set), using DCI-based beam management (DCI-level beam indication). X (>1) TCI states may be activated by the MAC CE. The UL/DL DCI may select one TCI state from X active TCI states. The selected TCI state may be applied to channels/RSs for both of the UL and DL.

The TCI pool (set) may be a plurality of TCI states configured by an RRC parameter, or may be a plurality of TCI states (active TCI states, an active TCI pool, a set) activated by the MAC CE out of the plurality of TCI states configured by the RRC parameter. Each TCI state may be a QCL type A/D RS. As the QCL type A/D RS, an SSB, a CSI-RS, or an SRS may be configured.

The number of TCI states corresponding to each of one or more TRPs may be defined. For example, the number N (≥1) of TCI states (UL TCI states) applied to UL channels/RSs and the number M (≥1) of TCI states (DL TCI states) applied to DL channels/RSs may be defined. At least one of N and M may be notified/configured/indicated to the UE via higher layer signaling/physical layer signaling.

In the present disclosure, description of N=M=X (X is any integer) may mean that X TCI states (joint TCI states) (corresponding to X TRPs) common to the UL and the DL are notified/configured/indicated to the UE. Description of N=X (X is any integer) and M=Y (Y is any integer and Y may be equal to X) may mean that X UL TCI states (corresponding to X TRPs) and Y DL TCI states (corresponding to Y TRPs) (that is, separate TCI states) are separately notified/configured/indicated to the UE.

For example, description of N=M=1 may mean that one TCI state common to the UL and the DL for a single TRP is notified/configured/indicated to the UE (joint TCI state for a single TRP).

For example, description of N=1 and M=1 may mean that one UL TCI state and one DL TCI state for a single TRP are separately notified/configured/indicated to the UE (separate TCI states for a single TRP).

For example, description of N=M=2 may mean that a plurality of (two) TCI states common to the UL and the DL for a plurality of (two) TRPs are notified/configured/indicated to the UE (joint TCI states for a plurality of TRPs).

For example, description of N=2 and M=2 may mean that a plurality of (two) UL TCI states and a plurality of (two) DL TCI states for a plurality of (two) TRPs are notified/configured/indicated to the UE (separate TCI states for a plurality of TRPs).

Note that, although the above examples describe cases in which the value of N and M is 1 or 2, the value of N and M may be 3 or greater, and N may be different from M.

FIG.1shows an example of activation of joint TCI states. One or more joint TCI states are configured by an RRC IE, and one or more joint TCI states out of the one or more joint TCI states are activated by a MAC CE. The one or more activated joint TCI states may be referred to as an active TCI state pool, an active joint TCI state pool, or the like.

FIGS.2A and2Bshow examples of activation of separate TCI states. As shown inFIG.2A, one or more UL TCI states are configured by an RRC IE, and one or more UL TCI states out of the one or more UL TCI states are activated by a MAC CE. As shown inFIG.2B, one or more DL TCI states are configured by an RRC IE, and one or more DL TCI states out of the one or more DL TCI states are activated by a MAC CE. The one or more activated UL TCI states may be referred to as an active TCI state pool, an active UL TCI state pool, an active separate TCI state pool, or the like. The one or more activated DL TCI states may be referred to as an active TCI state pool, an active DL TCI state pool, an active separate TCI state pool, or the like.

FIG.3Ashows an example of indication of a joint TCI state for a single TRP. N=M joint TCI states out of one or more joint TCI states are indicated by DCI. When N=M=1, a single joint TCI state for a single TRP is indicated. The TCI state is applied to both of the UL and the DL.

FIG.3Bshows an example of indication of a separate TCI state for a single TRP. N UL TCI states out of one or more UL TCI states are indicated by DCI. M DL TCI states out of one or more DL TCI states are indicated by DCI. When N=1 and M=1, a single separate TCI state for a single TRP is indicated (one UL TCI state and one DL TCI state are separately indicated). One UL TCI state is applied to the UL. One DL TCI state is applied to the DL.

FIG.4Ashows another example of indication of joint TCI states for a multi-TRP. When N=M=2, two joint TCI states for two TRPs (two sets of single joint TCI states) are indicated. A first joint TCI state (a first set) corresponds to a first TRP. A second joint TCI state (a second set) corresponds to a second TRP.

FIG.4Bshows another example of indication of separate TCI states for a multi-TRP. When N=2 and M=2, two separate TCI states for two TRPs (two sets of single separate TCI states) are indicated. A first UL TCI state (a first set) corresponds to a first TRP. A second UL TCI state (a second set) corresponds to a second TRP. A first DL TCI state (a first set) corresponds to a first TRP. A second DL TCI state (a second set) corresponds to a second TRP.

In NR, a scheme in which one or a plurality of transmission/reception points (TRPs) (multi-TRP (multi TRP (MTRP))) perform DL transmission to the UE by using one or a plurality of panels (multi-panel) has been under study. In addition, a scheme in which the UE performs UL transmission to one or a plurality of TRPs by using one or a plurality of panels has been under study.

Note that the plurality of TRPs may correspond to the same cell identifier (ID), or may correspond to different cell IDs. The cell ID (s) may be physical cell ID(s), or may be virtual cell ID (s).

The multi-TRP (for example, TRPs #1 and #2) is connected with an ideal/non-ideal backhaul, and information, data, and the like may be exchanged therebetween. Different codewords (Code Word, CWs) and different layers may be transmitted from each TRP of the multi-TRP. As one mode of multi-TRP transmission, non-coherent joint transmission (NCJT) may be used.

In NCJT, for example, TRP #1 performs modulation mapping on a first codeword, performs layer mapping, and transmits a first PDSCH in layers of a first number (for example, two layers) by using first precoding. TRP #2 performs modulation mapping on a second codeword, performs layer mapping, and transmits a second PDSCH in layers of a second number (for example, two layers) by using second precoding.

Note that it may be defined that a plurality of PDSCHs (multi-PDSCH) subjected to NCJT partially or entirely overlap in at least one of time and frequency domains. In other words, at least one of the time and frequency resources of the first PDSCH from the first TRP and the second PDSCH from the second TRP may overlap.

It may be assumed that these first PDSCH and second PDSCH are not in a relationship of quasi-co-location (QCL) (not quasi-co-located). Reception of the multi-PDSCH may be interpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (for example, QCL type D).

The plurality of PDSCHs (which may be referred to as multi-PDSCH (multiple PDSCHs)) from the multi-TRP may be scheduled using one piece of DCI (single DCI, single PDCCH) (single master mode, multi-TRP based on single DCI (single-DCI based multi-TRP)). The plurality of PDSCHs from the multi-TRP may be scheduled using a plurality of pieces of DCI (multi-DCI, multi-PDCCH (multiple PDCCHs)) (multi-master mode, multi-TRP based on multi-DCI (multi-DCI based multi-TRP)).

In Ultra-Reliable and Low Latency Communications (URLLC) for the multi-TRP, support of PDSCH (transport block (TB) or codeword (CW)) repetition across the multi-TRP has been under study. Support of repetition schemes (URLLC schemes, reliability enhancement schemes, for example, schemes 1a, 2a, 2b, 3, and 4) across the multi-TRP in the frequency domain, the layer (space) domain, or the time domain has been under study. In scheme 1a, the multi-PDSCH from the multi-TRP is subjected to space division multiplexing (SDM). In schemes 2a and 2b, the PDSCH from the multi-TRP is subjected to frequency division multiplexing (FDM). In scheme 2a, the redundancy versions (RVs) are the same for the multi-TRP. In scheme 2b, the RVs may be the same or may be different from one another for the multi-TRP. In schemes 3 and 4, the multi-PDSCH from the multi-TRP is subjected to time division multiplexing (TDM). In scheme 3, the multi-PDSCH from the multi-TRP is transmitted in one slot. In scheme 4, the multi-PDSCH from the multi-TRP is transmitted in different slots.

According to the multi-TRP scenario as described above, more flexible transmission control using a channel having satisfactory quality can be performed.

In order to support multi-TRP transmission within a cell (“intra-cell”, having the same cell ID) and among cells (“inter-cell”, having different cell IDs) based on a plurality of PDCCHs, in RRC configuration information for linking a plurality of pairs of PDCCHs and PDSCHs having a plurality of TRPs, one control resource set (CORESET) in PDCCH configuration information (PDCCH-Config) may correspond to one TRP.

When at least one of the following conditions1and2is satisfied, the UE may determine the multi-TRP based on multi-DCI. In this case, the TRP may be interpreted as a CORESET pool index.

One CORESET pool index is configured.

Two different values (for example, 0 and 1) of the CORESET pool index are configured.

When the following condition is satisfied, the UE may determine the multi-TRP based on single DCI. In this case, two TRPs may be interpreted as two TCI states indicated by a MAC CE/DCI.

Condition

In order to indicate one or two TCI states for one codepoint of a TCI field in the DCI, an “Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE” is used.

The DCI for common beam indication may be a UE-specific DCI format (for example, a DL DCI format (for example, 1_1, 1_2), a UL DCI format (for example, 0_1, 0_2)), or may be a UE-group common DCI format.

Regarding the PDCCH/CORESET defined in Rel. 15, one TCI state without a CORESET pool index (CORESETPoolIndex) (which may be referred to as TRP information (TRP Info)) is configured for one CORESET.

Regarding enhancements of the PDCCH/CORESET defined in Rel. 16, in the multi-TRP based on multi-DCI, the CORESET pool index is configured for each CORESET.

In Rel. 17 or later versions, the following enhancements 1 and 2 related to the PDCCH/CORESET have been under study.

In a case in which a plurality of antennas (small antennas, transmission/reception points) having the same cell ID form a single frequency network (SFN), up to two TCI states can be configured/activated for one CORESET, using higher layer signaling (RRC signaling/MAC CE) (enhancement 1). The SFN contributes to at least one of operation and reliability enhancement of an HST (high speed train).

In repetition transmission of the PDCCH (which may be simply referred to as “repetition”), two PDCCH candidates in two search space sets are linked to each other, and each search space set is associated with a corresponding CORESET (enhancement 2). The two search space sets may be associated with the same or different CORESET (s). For one CORESET, one (up to one) TCI state can be configured/activated using higher layer signaling (RRC signaling/MAC CE).

If the two search space sets are associated with different CORESETs having different TCI states, this may mean repetition transmission for a multi-TRP. If the two search space sets are associated with the same CORESET (CORESET having the same TCI state), this may mean repetition transmission for a single TRP.

In LTE, installation of an HST (high speed train) in a tunnel is difficult. A large antenna performs transmission to the outside/inside a tunnel. For example, a transmit power of a large antenna is approximately from 1 to 5 W. For handover, it is important to perform transmission to the outside of the tunnel before the UE enters the tunnel. For example, a transmit power of a small antenna is approximately 250 mW. A plurality of small antennas (transmission/reception points) having the same cell ID and having a distance of 300 m form a single frequency network (SFN). All of the small antennas in the SFN transmit the same signal in the same PRB at the same time. A terminal is assumed to perform transmission and reception to and from one base station. In actuality, a plurality of transmission/reception points transmit the same DL signal. In high-speed movement, transmission/reception points in a unit of several kilometers form one cell. In movement across cells, handover is performed. This allows the handover to be less frequent.

In NR, in order to perform communication with a terminal (hereinafter also referred to as a UE) included in a moving object (HST (high speed train)), such as a train, that moves at a high speed, using beams transmitted from transmission points (for example, RRHs) is assumed. In existing systems (for example, Rel. 15), performing communication with the moving object by transmitting uni-directional beams from the RRHs is supported (seeFIG.5A).

FIG.5Ashows a case in which the RRHs are installed along a movement path (or a moving direction, a traveling direction, a traveling path) of the moving object, and a beam is formed from each RRH toward the side of the traveling direction of the moving object. The RRH that forms the uni-directional beam may be referred to as a uni-directional RRH. In the example shown inFIG.5A, the moving object receives a negative Doppler shift (−fD) from each RRH.

Note that, here, a case is shown in which a beam is formed toward the side of the traveling direction of the moving object, but this is not restrictive, and a beam may be formed toward the side of a direction opposite to the traveling direction or a beam may be formed in every direction regardless of the traveling direction of the moving object.

In Rel. 16 and later versions, it is also assumed that a plurality of (for example, two or more) beams are transmitted from the RRH. For example, it is assumed that the beams are formed in both of the traveling direction of the moving object and a direction opposite to the traveling direction (seeFIG.5B).

FIG.5Bshows a case in which the RRHs are installed along the movement path of the moving object and beams are formed from each RRH toward both of the side of the traveling direction of the moving object and the side of the direction opposite to the traveling direction. The RRH that forms the beams of the plurality of directions (for example, two directions) may be referred to as a bi-directional RRH.

In the HST, the UE performs communication, similarly to a single TRP. In base station implementation, transmission from a plurality of TRPs (same cell ID) can be performed.

In the example ofFIG.5B, when two RRHs (here, RRH #1 and RRH #2) use the SFN and the moving object is located between the two RRHs, a signal subjected to a negative Doppler shift switches to a signal subjected to a positive Doppler shift having higher power. In this case, the largest change in the Doppler shift to require correction is a change from −fDto +fD, which is twice as large as that in the case of the uni-directional RRH.

Note that, in the present disclosure, a positive Doppler shift may be interpreted as information related to a positive Doppler shift, a Doppler shift in a positive direction, and Doppler information in a positive direction. A negative Doppler shift may be interpreted as information related to a negative Doppler shift, a Doppler shift in a negative direction, and Doppler information in a negative direction.

Here, as schemes for the HST, the following scheme 0 to scheme 2 (HST scheme 0 to HST scheme 2) are compared.

In scheme 0 ofFIG.6A, a tracking reference signal (TRS), a DMRS, and a PDSCH are transmitted to be common to two TRPs (RRHs) (using the same time and the same frequency resources) (a normal SFN, a transparent SFN, an HST-SFN).

In scheme 0, the UE receives DL channels/signals corresponding to a single TRP, and thus there is one TCI state of the PDSCH.

Note that, in Rel. 16, an RRC parameter for distinguishing transmission using a single TRP and transmission using an SEN is defined. When the UE reports corresponding UE capability information, the UE may distinguish reception of DL channels/signals of the single TRP and reception of the PDSCH assuming the SFN, based on the RRC parameter. In contrast, the UE may assume the single TRP and perform transmission and reception using the SFN.

In scheme 1 ofFIG.6B, TRSs are transmitted to be specific to respective TRPs (by using different time/frequency resources for the respective TRPs). In the example, TRS 1 is transmitted from TRP #1, and TRS 2 is transmitted from TRP #2.

In scheme 1, the UE receives DL channels/signals from respective TRPs by using the TRSs from the respective TRPs, and thus there are two TCI states of the PDSCH.

In scheme 2 ofFIG.6C, TRSs and DMRSs are transmitted to be specific to respective TRPs. In the example, TRS 1 and DMRS 1 are transmitted from TRP #1, and TRS 2 and DMRS 2 are transmitted from TRP #2. In comparison to scheme 0, schemes 1 and 2 can reduce sudden changes of Doppler shifts, and can allow appropriate estimation/compensation of the Doppler shifts. The DMRSs of scheme 2 are increased more than the DMRSs of scheme 1, and thus maximum throughput of scheme 2 is lower than that of scheme 1.

In scheme 0, the UE switches the single TRP and the SFN, based on higher layer signaling (RRC information element/MAC CE).

The UE may switch scheme 1/scheme 2/NW pre-compensation scheme, based on higher layer signaling (RRC information element/MAC CE).

In scheme 1, two TRS resources are configured, that are for the traveling direction of the HST and a direction opposite to the traveling direction.

In the example ofFIG.7A, the TRPs (TRPs #0, #2, . . . ) that transmit a DL signal in the direction opposite to the HST transmit a first TRS (TRS coming from ahead of the HST) in the same time and frequency resources (SFN). The TRPs (TRPs #1, #3, . . . ) that transmit a DL signal in the traveling direction of the HST transmit a second TRS (TRS coming from behind the HST) in the same time and frequency resources (SFN). The first TRS and the second TRS may be transmitted/received using frequency resources different from each other.

In the example ofFIG.7B, TRSs 1-1 to 1-4 are transmitted as the first TRS, and TRSs 2-1 to 2-4 are transmitted as the second TRS.

In consideration of operation of beams, the first TRS is transmitted using 64 beams and 64 time resources, and the second TRS is transmitted using 64 beams and 64 time resources. The beams of the first TRS and the beams of the second TRS are considered to be the same (the QCL type D RSs are the same). By multiplexing the first TRS and the second TRS on the same time resources and different frequency resources, resource use efficiency can be enhanced.

In the example ofFIG.8A, RRHs #0 to #7 are installed along the movement path of the HST. RRHs #0 to #3 and RRHs #4 to #7 are connected to baseband units (BBUs) #0 and #1, respectively. Each RRH is a bi-directional RRH, and forms beams using each transmission/reception point (TRP) in both of the traveling direction of the movement path and the direction opposite to the traveling direction.

In received signals in the example ofFIG.8B(single TRP (SFN)/scheme 1), when the UE receives signals/channels (beams in the traveling direction of the HST, beams from behind the UE) transmitted from TRPs #2n−1 (n is an integer of 0 or greater), a negative Doppler shift (in the example, −fD) occurs. When the UE receives signals/channels (beams in the direction opposite to the traveling direction of the HST, beams from ahead of the UE) transmitted from TRPs #2n (n is an integer of 0 or greater), a positive Doppler shift (in the example, +fD) occurs.

In Rel. 17 or later versions, the following has been under study in which the base station performs a Doppler pre-(preliminary) compensation (correction) scheme (a Pre-Doppler Compensation scheme, a Doppler pre-Compensation scheme, and a network (NW) pre-compensation scheme (an NW pre-compensation scheme and an HST NW pre-compensation scheme)) in transmission of downlink (DL) signals/channels to the UE in the HST from the TRP. The TRP performs Doppler compensation in advance for transmission of DL signals/channels to the UE, so that influence of Doppler shifts in the UE at the time of reception of the DL signals/channels can be reduced. In the present disclosure, the Doppler pre-compensation scheme may be a combination of scheme 1 and pre-compensation of Doppler shifts by the base station.

In the Doppler pre-compensation scheme, the following has been under study in which the TRS from each TRP is transmitted without being subjected to Doppler pre-compensation, and the PDSCH from each TRP is transmitted by being subjected to Doppler pre-compensation.

In the Doppler pre-compensation scheme, the TRPs that form beams toward the side of the traveling direction of the movement path and the TRPs that form beams toward the side of the direction opposite to the traveling direction of the movement path perform transmission of the DL signals/channels to the UE in the HST after performing Doppler correction. In the example, TRPs #2n−1 perform positive Doppler correction and TRPs #2n perform negative Doppler correction, and influence of Doppler shifts in the UE at the time of reception of signals/channels is thereby reduced (FIG.8C).

Note that, in the situation ofFIG.8C, the UE receives DL channels/signals from respective TRPs by using the TRSs from the respective TRPs, and thus there may be two TCI states of the PDSCH.

In addition, in Rel. 17 or later versions, dynamically switching between the single TRP and the SEN by using the TCI field (TCI state field) has been under study. For example, one or two TCI states are configured/indicated in each TCI codepoint (codepoint of the TCI field, the DCI codepoint), using an RRC information element/MAC CE (for example, the Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE)/DCI (TCI field). When one TCI state is configured/indicated, the UE may determine to receive the PDSCH of the single TRP. When two TCI states are configured/indicated, the UE may determine to receive the PDSCH of the SEN using the multi-TRP.

At least in frequency range 1 (FR1), definition of both of scheme 1 and the Doppler pre-compensation scheme in specifications has been under study. Application of these schemes to the PDSCH, the PDCCH, and the DMRSs thereof has been under study.

For the PDSCH, dynamically switching between scheme 1 and the single TRP depending on the number of TCI states indicated by the TCI field has been under study. For the PDSCH, dynamically switching between the Doppler pre-compensation scheme and the single TRP depending on the number of TCI states indicated by the TCI field has been under study.

If the UE does not have a UE capability for these dynamic switches, notification of two TCI states to all of the codepoints in the TCI field by a MAC CE has been under study.

Switching between scheme 1 and the Doppler pre-compensation scheme by an RRC IE has been under study.

However, a method of configuration/indication for scheme 1/Doppler pre-compensation scheme/single TRP has not yet been fully studied. Unless the study is fully conducted, the UE cannot appropriately perform reception of DL signals/channels, and reduction of communication quality/throughput may be caused.

In view of this, the inventors of the present invention came up with the idea of a method of configuration/indication for scheme 1/Doppler pre-compensation scheme/single TRP.

Embodiments according to the present disclosure will be described in detail with reference to the drawings as follows. The radio communication methods according to respective embodiments may each be employed individually, or may be employed in combination.

In the present disclosure, “A/B/C” and “at least one of A, B, and C” may be interchangeably interpreted. In the present disclosure, a cell, a serving cell, a CC, a carrier, a BWP, a DL BWP, a UL BWP, an active DL BWP, an active UL BWP, and a band may be interchangeably interpreted. In the present disclosure, an index, an ID, an indicator, and a resource ID may be interchangeably interpreted. In the present disclosure, a sequence, a list, a set, a group, a cluster, a subset, and the like may be interchangeably interpreted. In the present disclosure, to support, to control, to be able to control, to operate, and to be able to operate may be interchangeably interpreted.

In the present disclosure, configure, activate, update, indicate, enable, specify, and select may be interchangeably interpreted.

In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination of these. In the present disclosure, RRC, RRC signaling, an RRC parameter, a higher layer, a higher layer parameter, an RRC information element (IE), an RRC message, and a configuration may be interchangeably interpreted.

As the MAC signaling, for example, a MAC control element (MAC CE), a MAC Protocol Data Unit (PDU), or the like may be used. In the present disclosure, a MAC CE, an update command, and an activation/deactivation command may be interchangeably interpreted.

The broadcast information may be, for example, a master information block (MIB), a system information block (SIB), minimum system information (Remaining Minimum System Information (RMSI), SIB1), other system information (OSI), or the like.

In the present disclosure, a beam, a spatial domain filter, a space setting, a TCI state, a UL TCI state, a unified TCI state, a unified beam, a common TCI state, a common beam, a TCI assumption, a QCL assumption, a QCL parameter, a spatial domain reception filter, a UE spatial domain reception filter, a UE receive beam, a DL beam, a DL receive beam, DL precoding, a DL precoder, a DL-RS, an RS of QCL type D in a TCI state/QCL assumption, an RS of QCL type A in a TCI state/QCL assumption, a spatial relation, a spatial domain transmission filter, a UE spatial domain transmission filter, a UE transmit beam, a UL beam, a UL transmit beam, UL precoding, a UL precoder, and a PL-RS may be interchangeably interpreted. In the present disclosure, a QCL type X-RS, a DL-RS associated with QCL type X, a DL-RS having QCL type X, a source of a DL-RS, an SSB, a CSI-RS, and an SRS may be interchangeably interpreted.

In the present disclosure, a panel, an Uplink (UL) transmission entity, a TRP, a spatial relation, a control resource set (CORESET), a PDSCH, a codeword, a base station, an antenna port of a certain signal (for example, a demodulation reference signal (DMRS) port), an antenna port group of a certain signal (for example, a DMRS port group), a group for multiplexing (for example, a code division multiplexing (CDM) group, a reference signal group, a CORESET group), a CORESET pool, a CORESET subset, a CW, a redundancy version (RV), and a layer (a multi-input multi-output (MIMO) layer, a transmission layer, a spatial layer) may be interchangeably interpreted. A panel Identifier (ID) and a panel may be interchangeably interpreted. In the present disclosure, a TRP ID and a TRP may be interchangeably interpreted.

The panel may relate to at least one of a group index of an SSB/CSI-RS group, a group index of a group-based beam report, and a group index of an SSB/CSI-RS group for a group-based beam report.

A panel Identifier (ID) and a panel may be interchangeably interpreted. In other words, a TRP ID and a TRP, a CORESET group ID and a CORESET group, and the like may be interchangeably interpreted.

In the present disclosure, a TRP, a transmission point, a panel, a DMRS port group, a CORESET pool, and one of two TCI states associated with one codepoint of a TCI field may be interchangeably interpreted.

In the present disclosure, it may be assumed that the single PDCCH (DCI) is supported when the multi-TRP uses an ideal backhaul. It may be assumed that the multi-PDCCH (DCI) is supported when the multi-TRP uses a non-ideal backhaul.

Note that the ideal backhaul may be referred to as DMRS port group type 1, reference signal related group type 1, antenna port group type 1, CORESET pool type 1, or the like. The non-ideal backhaul may be referred to as DMRS port group type 2, reference signal related group type 2, antenna port group type 2, CORESET pool type 2, or the like. Terms are not limited to these.

In the present disclosure, a single TRP, a single TRP system, a single TRP transmission, and a single PDSCH may be interchangeably interpreted. In the present disclosure, a multi-TRP, a multi-TRP system, multi-TRP transmission, and a multi-PDSCH may be interchangeably interpreted. In the present disclosure, single DCI, a single PDCCH, multi-TRP based on single DCI, and activation of two TCI states in at least one TCI codepoint may be interchangeably interpreted.

In the present disclosure, a single TRP, a channel using a single TRP, a channel using one TCI state/spatial relation, no enabling of a multi-TRP by RRC/DCI, no enabling of a plurality of TCI states/spatial relations by RRC/DCI, and no configuration of one CORESET pool index (CORESETPoolIndex) value for any of the CORESETs and no mapping of any codepoint of a TCI field to two TCI states may be interchangeably interpreted.

In the present disclosure, a multi-TRP, a channel using a multi-TRP, a channel using a plurality of TCI states/spatial relations, enabling of a multi-TRP by RRC/DCI, enabling of a plurality of TCI states/spatial relations by RRC/DCI, and at least one of multi-TRP based on single DCI and multi-TRP based on multi-DCI may be interchangeably interpreted. In the present disclosure, multi-TRP based on multi-DCI and configuration of one CORESET pool index (CORESETPoolIndex) value for the CORESET may be interchangeably interpreted. In the present disclosure, multi-TRP based on single DCI and mapping of at least one codepoint of a TCI field to two TCI states may be interchangeably interpreted.

In the present disclosure, TRP #1 (first TRP) may correspond to CORESET pool index=0, or may correspond to a first TCI state of two TCI states corresponding to one codepoint of a TCI field. TRP #2 (second TRP) may correspond to CORESET pool index=1, or may correspond to a second TCI state of the two TCI states corresponding to one codepoint of the TCI field.

In the present disclosure, single DCI (sDCI), a single PDCCH, a single-DCI based multi-TRP system, an sDCI based MTRP, and activation of two TCI states in at least one TCI codepoint may be interchangeably interpreted.

In the present disclosure, multi-DCI (mDCI), a multi-PDCCH, a multi-DCI based multi-TRP system, an mDCI based MTRP, and configuration of two CORESET pool indices or CORESET pool index=1 (or value of one or more) may be interchangeably interpreted.

QCL in the present disclosure may be interchangeably interpreted as QCL type D.

“TCI state A is of the same QCL type D as TCI state B”, “TCI state A is the same as TCI state B”, “TCI state A is of QCL type D with TCI state B”, and the like in the present disclosure may be interchangeably interpreted.

In the present disclosure, a DMRS, a DMRS port, and an antenna port may be interchangeably interpreted.

In the present disclosure, a CSI-RS, an NZP-CSI-RS, a periodic (P)-CSI-RS, a P-TRS, a semi-persistent (SP)-CSI-RS, an aperiodic (A)-CSI-RS, a TRS, a tracking CSI-RS, a CSI-RS having TRS information (a higher layer parameter trs-Info), NZP CSI-RS resources in an NZP CSI-RS resource set having TRS information, NZP-CSI-RS resources in an NZP-CSI-RS resource set including a plurality of NZP-CSI-RS resources of the same antenna port, and TRS resources may be interchangeably interpreted. In the present disclosure, CSI-RS resources, a CSI-RS resource set, a CSI-RS resource group, and an information element (IE) may be interchangeably interpreted.

In the present disclosure, a codepoint of a DCI field ‘Transmission Configuration Indication’, a TCI codepoint, a DCI codepoint, and a codepoint of a TCI field may be interchangeably interpreted.

In the present disclosure, a single TRP and an SFN may be interchangeably interpreted. In the present disclosure, an HST, an HST scheme, a scheme for high-speed movement, scheme 1, scheme 2, a NW pre-compensation scheme, HST scheme 1, HST scheme 2, and an HST NW pre-compensation scheme may be interchangeably interpreted.

In the present disclosure, a PDSCH/PDCCH using a single TRP may be interpreted as a PDSCH/PDCCH based on a single TRP and a single TRP PDSCH/PDCCH. In the present disclosure, a PDSCH/PDCCH using an SFN may be interpreted as a PDSCH/PDCCH using an SFN in multi TRP, a PDSCH/PDCCH based on an SFN, and an SFN PDSCH/PDCCH.

In the present disclosure, reception of a DL signal (PDSCH/PDCCH) using an SFN may mean use of the same time/frequency resources and/or reception of the same data (PDSCH)/control information (PDCCH) from a plurality of transmission/reception points. Reception of a DL signal using an SFN may mean use of the same time/frequency resource and/or reception of the same data/control information by using a plurality of TCI states/spatial domain filters/beams/QCLs.

In the present disclosure, information related to Doppler correction (compensation), Doppler correction information, Doppler information, information related to a Doppler shift, a Doppler shift, Doppler spread, a Doppler shift and Doppler spread, a Doppler report, and Doppler report information may be interchangeably interpreted.

In the present disclosure, an SFN scheme of Rel. 16, an existing SFN scheme, an existing HST-SFN scheme, an advanced receiver function, configuration of an advanced receiver function and indication of one TCI state, and single TRP reception of Rel. 15 may be interchangeably interpreted.

In the present disclosure, an SFN scheme of Rel. 17 or later versions, a new SFN scheme, a new HST-SFN scheme, an HST-SFN scenario of Rel. 17 or later versions, and at least one of scheme 1 (HST scheme 1) and a Doppler pre-compensation scheme may be interchangeably interpreted.

Radio Communication Method

First Embodiment

In Rel. 16, the UE reports whether the UE has an advanced receiver function by using UE capability information (HighSpeedParameters-r16, measurementEnhancement-r16/demodulationEnhancement-r16). The advanced receiver function is at least one of to simultaneously measure TRSs from two directions (for example, front and back directions with respect to the traveling direction) of the UE and to simultaneously decode PDSCHs from the two directions. The advanced receiver function may be to satisfy performance of measurement/decoding defined in specifications. When the UE is configured with the advanced receiver function by using configuration information (RRC IE, HighSpeedConfig-r16, highSpeedMeasFlag-r16/highSpeedDemodFlag-r16), the UE operates using a corresponding advanced receiver function.

The UE that has reported specific UE capability information may operate using the new SFN scheme (scheme 1/Doppler pre-compensation scheme). The UE that has received specific configuration information may operate using the new SFN scheme. The UE that has reported the specific UE capability information and received the specific configuration information may operate using the new SFN scheme.

The specific UE capability information may be UE capability information of the advanced receiver function of Rel. 16, may be new UE capability information of the new SFN scheme, or may be both of the UE capability information of the advanced receiver function of Rel. 16 and the new UE capability information. The UE that supports the new SFN scheme may require (as a condition) support of the advanced receiver function of Rel. 16.

The specific configuration information may be configuration information of the advanced receiver function of Rel. 16, may be new configuration information of the new SFN scheme, or may be both of the configuration information of the advanced receiver function of Rel. 16 and the new configuration information. The UE configured with the new SFN scheme may require (as a condition) being configured with the advanced receiver function of Rel. 16.

<<Notification Method for TCI State (s) of Scheme 1>>

In scheme 1, one or two TCI states may be notified/indicated by an RRC IE/MAC CE/DCI. When one TCI state is notified, the UE may operate similarly to the single TRP of Rel. 15. When two TCI states are notified, the UE may operate using scheme 1.

For the PDSCH, an RRC IE/MAC CE for configuring one or two TCI states for one codepoint of the TCI field may be used for each piece of PDSCH configuration information (PDSCH-Config). The MAC CE may be the Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE in Rel. 16. Scheme 1 and the single TRP may be dynamically switched by the DCI.

For the PDCCH, an RRC IE/MAC CE for configuring one or two TCI states for one codepoint of the DCI may be used for each CORESET (or piece of PDCCH configuration information (PDCCH-Config)). The MAC CE may be newly defined in specifications of Rel. 17 or later versions. Scheme 1 and the single TRP need not be dynamically switched by the DCI. Scheme 1 and the single TRP may be switched after a certain time has elapsed since reception of the DCI.

<<Notification Method for TCI State (s) of Doppler Pre-Compensation Scheme>>

In the Doppler pre-compensation scheme, one or two TCI states may be notified/indicated by an RRC IE/MAC CE/DCI. When one TCI state is notified, the UE may operate similarly to the single TRP of Rel. 15. When two TCI states are notified, the UE may operate using the Doppler pre-compensation scheme.

For the PDSCH, an RRC IE/MAC CE for configuring one or two TCI states for one codepoint of the TCI field may be used for each piece of PDSCH configuration information (PDSCH-Config). The MAC CE may be the Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE in Rel. 16. The Doppler pre-compensation scheme and the single TRP may be dynamically switched by the DCI.

For the PDCCH, an RRC IE/MAC CE for configuring one or two TCI states for one codepoint of the DCI may be used for each CORESET (or piece of PDCCH configuration information (PDCCH-Config)). The MAC CE may be newly defined in specifications of Rel. 17 or later versions. The Doppler pre-compensation scheme and the single TRP need not be dynamically switched by the DCI. The Doppler pre-compensation scheme and the single TRP may be switched after a certain time has elapsed since reception of the DCI.

In the Doppler pre-compensation scheme, when the same DMRS port is associated with two TCI states including the TRSs as source reference signals, one QCL assumption method of the following QCL assumption methods A, B, C, and E may be supported. [QCL Assumption Method A] One of the two TCI states is associated with {average delay, delay spread}, and the other is associated with {average delay, delay spread, Doppler shift, Doppler spread} (that is, QCL-TypeA).

[QCL Assumption Method B] One of the two TCI states is associated with {average delay, delay spread}, and the other is associated with {Doppler shift, Doppler spread} (that is, QCL-TypeB). [QCL Assumption Method C] One of the two TCI states is associated with {delay spread}, and the other is associated with {average delay, delay spread, Doppler shift, Doppler spread} (that is, QCL-TypeA).

[QCL Assumption Method E] Both of the Two TCI States are Associated with {Average Delay, Delay Spread, Doppler Shift, Doppler Spread} (that is, QCL-TypeA).

The UE may measure the QCL parameters from the TRSs from the TRPs, and may use those for reception/correction of the DMRS/PDSCH/PDCCH.

FIGS.9A to9Dare diagrams to show examples of a delay profile and an average delay.

In the example ofFIG.9A, the UE measures the average delay, using TRS #1 corresponding to TRP #1. In the example ofFIG.9B, the UE measures the average delay, using TRS #2 corresponding to TRP #2. When QCL assumption method A is used, as in the example ofFIG.9C, the UE may measure/calculate the average delay for TRP #1 and TRP #2, using TRS #1 and TRS #2. When QCL assumption method C is used, as in the example ofFIG.9D, the UE may measure/calculate the average delay for TRP #1, using TRS #1.

When QCL assumption method A is used, one of the two TRPs may be an anchor TRP. The TCI state corresponding to the anchor TRP may be associated with QCL-TypeA, and Doppler pre-compensation need not be performed on the DMRS/PDSCH/PDCCH from the anchor TRP. The UE may measure the Doppler shift and the Doppler spread by using the TRS from the anchor TRP, and may perform Doppler compensation using the measurement results. Doppler pre-compensation may be performed on the DMRS/PDSCH/PDCCH from the TRP not being an anchor. The UE need not measure the Doppler shift and the Doppler spread by using the TRS from the TRP not being an anchor, nor need not perform Doppler compensation.

A new QCL type may be defined in specifications. The QCL parameters associated with the new QCL type may be different from at least a part of the QCL parameters associated with the existing QCL types (QCL-TypeA to QCL-TypeD). The new QCL type may be associated with QCL parameters other than the Doppler shift and the Doppler spread. In the Doppler pre-compensation scheme, the UE may assume that one of the two TCI states is of the new QCL type.

The TCI state for the PDSCH/PDCCH may be a unified TCI state (common TCI state).

Second Embodiment

In the Doppler pre-compensation scheme, when two TCI states are notified, a part of specific QCL parameters in the QCL parameters of the QCL type indicated by the two TCI states may be ignored/omitted.

In the present disclosure, “the UE ignores a specific QCL parameter”, “the specific QCL parameter is omitted”, “the UE drops the specific QCL parameter”, “the UE does not use the specific QCL parameter for reception”, “the UE assumes that a DMRS port of a DL channel is not quasi co-located with an RS related to the specific QCL parameter”, “the UE assumes that a DMRS port of a DL channel is not quasi co-located with an RS related to a first QCL parameter (specific QCL parameter) in a TCI state but the DMRS port is quasi co-located with an RS related to a second QCL parameter (QCL parameter other than the specific QCL parameter) in the TCI state”, and “the UE does not apply the first QCL parameter (specific QCL parameter) in a TCI state to a DL channel but applies the second QCL parameter (QCL parameter other than the specific QCL parameter) in the TCI state to the DL channel” may be interchangeably interpreted.

The new QCL type need not be defined in specifications. In this case, influence on specifications can be reduced.

The UE may be indicated with one or two TCI states by a MAC CE/DCI, and determine which QCL parameter in which TCI state is to be ignored, based on other information.

Which QCL parameter in which TCI state is to be ignored may conform to at least one of the following notification methods 1 to 3.

Notification Method 1

When QCL assumption method A is defined in specifications, which of the two TCI states is the specific TCI state may be notified, or may be defined in specifications. {average delay, delay spread, Doppler shift, Doppler spread} in the TCI state different from the specific TCI state in the two TCI states may be applied (need not be ignored).

Notification Method 2

When QCL assumption method B is defined in specifications, which of the two TCI states is the specific TCI state may be notified, or may be defined in specifications. {average delay, delay spread} in the TCI state different from the specific TCI state in the two TCI states need not be applied (may be ignored).

Notification Method 3

When both of QCL assumption methods A and B are defined in specifications, which QCL assumption method of QCL assumption methods A and B is to be applied may be configured by an RRC IE (different from that for notification of the TCI states). Which QCL assumption method of QCL assumption methods A and B is to be applied may be configured for each BWP, may be configured for each cell, may be configured for each band, or may be configured for each UE. Notification method 1 and notification method 2 may be switched by the RRC IE.

When both of QCL assumption methods A and B are defined in specifications, which QCL assumption method of QCL assumption methods A and B is to be applied need not be configured by an RRC IE (different from that for notification of the TCI states). Which QCL assumption method of QCL assumption methods A and B is to be applied may be notified for each TCI state.

In notification methods 1 to 3 described above, although QCL assumption methods A and B are described, these are not restrictive. Instead of QCL assumption method A/B, one of QCL assumption methods A, B, C, and E may be used.

The UE may assume that a DMRS port of a DL channel is not quasi co-located with an RS in one TCI state regarding the specific QCL parameter, and assume that the DMRS port is quasi co-located with an RS in the TCI state regarding a QCL parameter other than the specific QCL parameter.

According to the embodiment, the UE can apply an appropriate QCL parameter in the TCI state for reception.

<<Specific TCI State for PDSCH>>

When the Doppler pre-compensation scheme is configured/indicated, regarding the UE, a part of the specific QCL parameters of the specific TCI state in two TCI states indicated for the PDSCH is to be ignored/omitted. A fact that the specific QCL parameter of the specific TCI state is to be ignored/omitted may be explicitly notified/configured by an RRC IE, or need not be explicitly notified/configured.

For the two TCI states associated with one codepoint of the TCI field, the same QCL type may be configured, or different QCL types may be configured.

The specific TCI state may conform to one of the following specification methods 1 to 3.

Specification Method 1

The specific TCI state may be defined in specifications. The specific TCI state may be a second (last) TCI state in the two TCI states associated with one codepoint indicated by DCI (TCI field). For example, the UE may ignore {Doppler shift, Doppler spread} of the second TCI state. When two TCI states are associated with one codepoint indicated by DCI (TCI field), the specific TCI state may be a first (initial) TCI state in the two TCI states.

In the examples ofFIGS.10A and10B, active TCI state IDs for respective codepoints (values) of the TCI field are indicated by a MAC CE. According to the MAC CE, one TCI state is activated for each of codepoints 000 to 011, and two TCI states are activated for each of codepoints 100 to 111.

In the example ofFIG.10A, the specific TCI state is the second TCI state. When one of codepoints 100 to 111 is indicated by the TCI field, the UE ignores the specific QCL parameter of the second TCI state in the two TCI states associated with the codepoint.

In the example ofFIG.10B, the specific TCI state is the first TCI state in the two TCI states associated with one codepoint. When one of codepoints 100 to 111 is indicated by the TCI field, the UE ignores the specific QCL parameter of the first TCI state in the two TCI states associated with the codepoint.

A maximum number of active TCI states may be defined in specifications. The maximum number of active TCI states may be 8, or may be other number.

When the base station associates two TCI states with one codepoint of the TCI field, the base station can determine and notify which of the two TCI states is the specific TCI state. With the MAC CE, two codepoints may be each associated with the same two TCI states, and the order of the two TCI states may be different between the two codepoints. For example, (TCI #4, TCI #5) may be associated with one codepoint, and (TCI #5, TCI #4) may be associated with the other codepoint. The base station can dynamically indicate the specific TCI state as one of TCIs #5 and #4 by a value of the TCI field.

Specification Method 2

The specific TCI state may be indicated. The specific TCI state may conform to one of the following indication methods 1 to 3.

Indication Method 1

For every codepoint associated with two TCI states, at which position the specific TCI state is located in the two TCI states may be indicated by an RRC IE/MAC CE/DCI. When it is indicated that the specific TCI state is the first TCI state and the codepoint associated with the two TCI states is indicated, the UE may ignore the specific QCL parameter of the first TCI state in the two TCI states. When it is indicated that the specific TCI state is the second TCI state, the UE may ignore the specific QCL parameter of the second TCI state associated with the indicated codepoint.

Indication Method 2

For each codepoint, at which position the specific TCI state is located in the two TCI states associated with the codepoint may be indicated by an RRC IE/MAC CE/DCI. For example, indication of the specific TCI may be N bits (bitmap), and the indication of N bits may correspond to respective N codepoints of the TCI field. When a certain bit is 0, the specific TCI state corresponding to the bit may be the first TCI state, and when the bit is 1, the specific TCI state corresponding to the bit may be the second TCI state. For example, when N is 8, in the indication {01010101} of the specific TCI, the specific TCI state for codepoints 000, 010, 100, and 110 may be the first TCI state, and the specific TCI state for codepoints 001, 011, 101, and 111 may be the second TCI state. N may be the number of all of the codepoints of the TCI field, or may be the number of codepoints associated with the two TCI states.

In the example ofFIG.11, active TCI state IDs for respective codepoints (values) of the TCI field are indicated by a MAC CE. According to the MAC CE, one TCI state is activated for each of codepoints 000 to 011, and two TCI states are activated for each of codepoints 100 to 111. In the example, the 4-bit indication of the specific TCI state corresponds to four codepoints 100 to 111 associated with the two TCI states. When the indication of the specific TCI state is {0101}, the specific TCI state for codepoint 100 is the first TCI state, the specific TCI state for codepoint 101 is the second TCI state, the specific TCI state for codepoint 110 is the first TCI state, and the specific TCI state for codepoint 111 is the second TCI state.

Indication Method 3

For a specific codepoint, at which position the specific TCI state is located in the two TCI states associated with the specific codepoint may be indicated by an RRC IE/MAC CE/DCI. For example, the specific codepoint may be a maximum codepoint (for example, 111), or may be a minimum codepoint (for example, 000). In this case, overhead of indication of the specific TCI state can be reduced.

Specification Method 3

The specific TCI state may be associated with a specific QCL type. For the two TCI states associated with one codepoint of the TCI field, different QCL types may be configured. The specific TCI state may be a TCI state configured with the specific QCL type among the two TCI states. The UE may ignore the specific QCL parameter in the TCI state configured with the specific QCL type among the two TCI states.

When QCL assumption method B is used, QCL type A is configured for one of the two TCI states associated with the codepoint indicated by DCI, and QCL type B is configured for the other, the UE may ignore the specific QCL parameter in the TCI state of QCL type A. In this case, overhead of indication of the specific TCI state can be reduced.

According to the operation of reception of the PDSCH using the Doppler pre-compensation scheme described above, the UE can use an appropriate QCL parameter in reception of the PDSCH using the Doppler pre-compensation scheme.

<<Specific TCI State for PDCCH>>

When the Doppler pre-compensation scheme is configured/indicated, the UE ignores/omits a part of the specific QCL parameters of the specific TCI state in two TCI states indicated for the PDCCH. A fact that the specific QCL parameter of the specific TCI state is to be ignored/omitted may be explicitly notified/configured by an RRC IE, or need not be explicitly notified/configured.

For the two TCI states associated with one codepoint of the TCI field, the same QCL type may be configured, or different QCL types may be configured.

The specific TCI state may conform to one of the following specification methods 1 to 3.

Specification Method 1

The specific TCI state may be defined in specifications. The specific TCI state may be a second (last) TCI state in the two TCI states associated with the CORESET. For example, the UE may ignore {Doppler shift, Doppler spread} of the second TCI state. When two TCI states are associated with the CORESET, the specific TCI state may be a first (initial) TCI state in the two TCI states.

In the examples ofFIGS.12A and12B, active TCI state IDs for the CORESET are indicated by a MAC CE. According to the MAC CE, two TCI states are activated for the CORESET.

In the example ofFIG.12A, the specific TCI state is the second TCI state. When two TCI states are activated for the CORESET, the UE ignores the specific QCL parameter of the second TCI state in the two TCI states.

In the example ofFIG.12B, the specific TCI state is the first TCI state in the two TCI states associated with the CORESET. When two TCI states are activated for the CORESET, the UE ignores the specific QCL parameter of the first TCI state in the two TCI states.

In order to change the specific TCI state, order of the two TCI states associated with the CORESET may be changed (may be exchanged) by a MAC CE.

Specification Method 2

The specific TCI state may be indicated.

For the CORESET associated with two TCI states, at which position the specific TCI state is located in the two TCI states may be indicated by an RRC IE/MAC CE/DCI. When the CORESET is associated with two TCI states and it is indicated that the specific TCI state is the first TCI state, the UE may ignore the specific QCL parameter of the first TCI state in the two TCI states. When it is indicated that the specific TCI state is the second TCI state, the UE may ignore the specific QCL parameter of the second TCI state associated with the CORESET.

In the examples ofFIGS.13A and13B, active TCI state IDs for the CORESET are indicated by a MAC CE. According to the MAC CE, two TCI states are activated for the CORESET.

In the example ofFIG.13A, when it is indicated that the specific TCI state is the second TCI state, the UE ignores the specific QCL parameter of the second TCI state in the two TCI states associated with the CORESET.

In the example ofFIG.13B, when it is indicated that the specific TCI state is the first TCI state, the UE ignores the specific QCL parameter of the first TCI state in the two TCI states associated with the CORESET.

For the CORESET associated with the two TCI states, when which one of the two TCI states is the specific TCI state is indicated by DCI, the UE may ignore the specific QCL parameter of the specific TCI state for the CORESET in reception of the PDCCH in the CORESET later than a specific timing. The specific timing may be a time point after a specific time has elapsed since end of ACK transmission indicated by the DCI. The specific time may be defined in specifications, may be configured by an RRC IE, or may be reported as UE capability information. The specific time may be K symbols. The specific TCI state indicated by the DCI may be applied to the PDCCH and the PDSCH. The DCI may be DCI for indicating a unified TCI state (common TCI state).

Specification Method 3

The specific TCI state may be associated with a specific QCL type. For the two TCI states associated with the CORESET, different QCL types may be configured. The specific TCI state may be a TCI state configured with the specific QCL type among the two TCI states. The UE may ignore the specific QCL parameter in the TCI state configured with the specific QCL type among the two TCI states.

When QCL assumption method B is used, QCL type A is configured for one of the two TCI states associated with the CORESET, and QCL type B is configured for the other, the UE may ignore the specific QCL parameter in the TCI state of QCL type A. In this case, overhead of indication of the specific TCI state can be reduced.

According to the operation of reception of the PDCCH using the Doppler pre-compensation scheme described above, the UE can use an appropriate QCL parameter in reception of the PDCCH using the Doppler pre-compensation scheme.

Third Embodiment

The SFN scheme of a DL channel may be configured by an RRC IE/MAC CE/DCI.

The SEN scheme of a DL channel may be configured by an RRC IE (RRC parameter).

One of scheme 1 and the Doppler pre-compensation scheme may be configured by a specific parameter (RRC IE). When the SFN scheme of one of scheme 1 and the Doppler pre-compensation scheme is configured by the specific parameter, and two TCI states are indicated by an RRC IE/MAC CE/DCI, the UE may operate using the SFN scheme.

<<Configuration Common to PDSCH and PDCCH>>

The PDCCH configuration information (PDCCH-Config) may include the specific parameter. The UE may apply the specific parameter configured by the PDCCH configuration information for a certain BWP of a certain cell to all of the PDCCHs/PDSCHs in the cell and the BWP.

CORESET configuration information (ControlResourceSet) may include the specific parameter. The UE may apply the specific parameter configured by the CORESET configuration information indicating a certain CORESET to all of the PDCCHs in the CORESET and all of the PDSCHs scheduled by the PDCCHs.

The PDSCH configuration information (PDSCH-Config) may include the specific parameter. The UE may apply the specific parameter configured by the PDSCH configuration information for a certain BWP of a certain cell to all of the PDCCHs/PDSCHs in the cell and the BWP.

The specific parameter may be configured for each cell or BWP. Serving cell configuration information (ServingCellConfig) or BWP configuration information (BWP, downlink BWP-dedicated configuration information (BWP-DownlinkDedicated)) may include the specific parameter. The UE may apply the specific parameter for a certain cell or a certain BWP to all of the PDCCHs/PDSCHs in the cell or the BWP.

The specific parameter may be configured for each UE. The UE may apply the specific parameter to all of the PDCCHs/PDSCHs in all of the BWPs/cells/bands.

When the configuration of the SFN scheme for the PDCCH and the PDSCH is the same, UE processing can be simplified.

<<Configuration Dedicated to PDSCH and PDCCH>>

The PDCCH configuration information (PDCCH-Config) may include the specific parameter. The UE may apply the specific parameter configured by the PDCCH configuration information for a certain BWP of a certain cell to all of the PDCCHs in the cell and the BWP.

The CORESET configuration information (ControlResourceSet) may include the specific parameter. The UE may apply the specific parameter configured by the CORESET configuration information indicating a certain CORESET to all of the PDCCHs in the CORESET.

The PDSCH configuration information (PDSCH-Config) may include the specific parameter. The UE may apply the specific parameter configured by the PDSCH configuration information for a certain BWP of a certain cell to all of the PDSCHs in the cell and the BWP.

The specific parameter for the PDSCH and the specific parameter for the PDCCH may be configured for each UE. The UE may apply the specific parameter for the PDSCH to all of the PDSCHs in all of the BWPs/cells/bands. The UE may apply the specific parameter for the PDCCH to all of the PDCCHs in all of the BWPs/cells/bands.

When the SFN scheme for the PDSCH and the SFN scheme for the PDCCH are separately configured, the SFN scheme can be flexibly configured.

Fourth Embodiment

The UE may determine (may switch) the SFN scheme to be used for the PDCCH, based on an RRC IE (RRC parameter) and the number of TCI states for the PDCCH.

The SFN scheme common to all of the CORESETs may be configured. The SFN scheme need not be applied to all of the CORESETs.

One of SFN scheme (scheme 1 or Doppler pre-compensation scheme) operation and single TRP operation may be indicated by an RRC IE/MAC CE/DCI.

For the PDCCH, dynamically switching between the SFN scheme operation and the single TRP operation may be permitted. The dynamically indicated SFN scheme operation or single TRP operation may be applied to the PDSCH.

The UE may apply the single TRP operation to reception of the PDCCH in the CORESET associated with one TCI state. The UE may apply the SFN scheme operation to reception of the PDCCH in the CORESET associated with two TCI states.

In the example ofFIG.14, whether to use the SFN scheme is configured for the UE by an RRC IE. When the SFN scheme is not configured, the UE applies the single TRP operation to reception of the PDCCH in the CORESET, regardless of the number of TCI states associated with the CORESET. When the SFN scheme is configured and the number of TCI states associated with the CORESET is 1, the UE applies the single TRP operation to reception of the PDCCH in the CORESET. When the SFN scheme is configured and the number of TCI states associated with the CORESET is 2, the UE applies the SFN scheme operation to reception of the PDCCH in the CORESET.

The UE may receive DCI for indicating one or two TCI states for the CORESET. The UE that has received the DCI may ignore the specific QCL parameter of the specific TCI state for the CORESET in reception of the PDCCH in the CORESET later than a specific timing. The specific timing may be a time point after a specific time has elapsed since end of ACK transmission indicated by the DCI. The specific time may be defined in specifications, may be configured by an RRC IE, or may be reported as UE capability information. The specific time may be K symbols. The one or two TCI states indicated by the DCI may be applied to the PDCCH and the PDSCH. The one or two TCI states indicated by the DCI may be unified TCI state (s) (common TCI state (s)).

Only the UE that has reported a UE capability indicating support of dynamic switch between the SFN scheme operation and the single TRP operation may receive indication of one of the SEN scheme operation and the single TRP operation. For all of the CORESETs of the UE that has not reported the UE capability, the same number of TCI states may be configured/indicated. For example, for all of the CORESETs of the UE that has not reported the UE capability, two TCI states may be configured/indicated.

For the PDCCH, dynamically switching between the SEN scheme operation and the single TRP operation need not be permitted. It may be defined that the UE does not assume that different numbers of TCI states are indicated for a plurality of different CORESETs. For all of the CORESETs, the same number of TCI states may be configured/indicated. For example, for all of the CORESETs, two TCI states may be configured/indicated.

According to the embodiment, the SFN scheme operation and the single TRP operation can be dynamically switched, and appropriate operation can be performed depending on a situation.

OTHER EMBODIMENTS

A higher layer parameter (RRC IE)/UE capability corresponding to a function (characteristic, feature) in each embodiment described above may be defined. The higher layer parameter may indicate whether the function is to be enabled. The UE capability may indicate whether the UE supports the function.

The UE configured with the higher layer parameter corresponding to the function may perform the function. “The UE not configured with the higher layer parameter corresponding to the function does not perform the function (for example, in conformity to Rel. 15/16)” may be defined.

The UE that has reported the UE capability indicating support of the function may perform the function. “The UE that has not reported the UE capability indicating support of the function does not perform the function (for example, in conformity to Rel. 15/16)” may be defined.

When the UE reports the UE capability indicating support of the function and is configured with the higher layer parameter corresponding to the function, the UE may perform the function. “When the UE does not report the UE capability indicating support of the function or is not configured with the higher layer parameter corresponding to the function, the UE does not perform the function (for example, in conformity to Rel. 15/16)” may be defined.

The UE capability may indicate whether to support the HST-SFN scheme.

The UE capability may indicate whether to support dynamic switch between the HST-SFN scheme and the single TRP using the TCI field for the PDSCH.

The UE capability may indicate whether to support dynamic switch between the HST-SFN scheme and the single TRP using the number of TCI states associated with the CORESET for the PDCCH.

The UE capability may indicate whether to support a function related to the specific TCI state for the PDSCH of the first embodiment. The UE capability may indicate whether to support a function related to the specific TCI state for the PDCCH of the first embodiment.

The UE capability may indicate whether to support the Doppler pre-correction scheme.

The UE capability may be at least one of the UE capability information of the advanced receiver function of Rel. 16 and the new UE capability information.

According to the embodiments described above, the UE can implement the above functions while maintaining compatibility with existing specifications.

The radio communication system1may support dual connectivity between a plurality of base stations in the same RAT (for example, dual connectivity (NR-NR Dual Connectivity (NN-DC)) where both of an MN and an SN are base stations (gNB) of NR).

The radio communication system1may include a base station11that forms a macro cell C1of a relatively wide coverage, and base stations12(12ato12c) that form small cells C2, which are placed within the macro cell C1and which are narrower than the macro cell C1. The user terminal20may be located in at least one cell. The arrangement, the number, and the like of each cell and user terminal20are by no means limited to the aspect shown in the diagram. Hereinafter, the base stations11and12will be collectively referred to as “base stations10,” unless specified otherwise.

The user terminal20may be connected to at least one of the plurality of base stations10. The user terminal20may use at least one of carrier aggregation (CA) and dual connectivity (DC) using a plurality of component carriers (CCs).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1may be included in FR1, and the small cells C2may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHZ), and FR2 may be a frequency band which is higher than 24 GHZ (above-24 GHz). Note that frequency bands, definitions and so on of FR1 and FR2 are by no means limited to these, and for example, FR1 may correspond to a frequency band which is higher than FR2.

The user terminal20may communicate using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

The plurality of base stations10may be connected by a wired connection (for example, optical fiber in compliance with the Common Public Radio Interface (CPRI), the X2 interface and so on) or a wireless connection (for example, an NR communication). For example, if an NR communication is used as a backhaul between the base stations11and12, the base station11corresponding to a higher station may be referred to as an “Integrated Access Backhaul (IAB) donor,” and the base station12corresponding to a relay station (relay) may be referred to as an “IAB node.”

The base station10may be connected to a core network30through another base station10or directly. For example, the core network30may include at least one of Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), and so on.

The user terminal20may be a terminal supporting at least one of communication schemes such as LTE, LTE-A, 5G, and so on.

In the radio communication system1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), which is used by each user terminal20on a shared basis, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)) and so on, may be used as downlink channels.

In the radio communication system1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), which is used by each user terminal20on a shared basis, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)) and so on may be used as uplink channels.

User data, higher layer control information, System Information Blocks (SIBs) and so on are communicated on the PDSCH. User data, higher layer control information and so on may be communicated on the PUSCH. The Master Information Blocks (MIBs) may be communicated on the PBCH.

Lower layer control information may be communicated on the PDCCH. For example, the lower layer control information may include downlink control information (DCI) including scheduling information of at least one of the PDSCH and the PUSCH.

Uplink control information (UCI) including at least one of channel state information (CSI), transmission confirmation information (for example, which may be also referred to as Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK/NACK, and so on), and scheduling request (SR) may be communicated by means of the PUCCH/PUSCH. By means of the PRACH, random access preambles for establishing connections with cells may be communicated.

In the radio communication system1, a synchronization signal (SS), a downlink reference signal (DL-RS), and so on may be communicated. In the radio communication system1, a cell-specific reference signal (CRS), a channel state information-reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), and so on may be communicated as the DL-RS.

In the radio communication system1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), and so on may be communicated as an uplink reference signal (UL-RS). Note that DMRS may be referred to as a “user terminal specific reference signal (UE-specific Reference Signal).”

FIG.16is a diagram to show an example of a structure of the base station according to one embodiment. The base station10includes a control section110, a transmitting/receiving section120, transmitting/receiving antennas130and a communication path interface (transmission line interface)140. Note that the base station10may include one or more control sections110, one or more transmitting/receiving sections120, one or more transmitting/receiving antennas130, and one or more communication path interfaces140.

Note that, the present example primarily shows functional blocks that pertain to characteristic parts of the present embodiment, and it is assumed that the base station10may include other functional blocks that are necessary for radio communication as well. Part of the processes of each section described below may be omitted.

The control section110controls the whole of the base station10. The control section110can be constituted with a controller, a control circuit, or the like described based on general understanding of the technical field to which the present disclosure pertains.

The control section110may control generation of signals, scheduling (for example, resource allocation, mapping), and so on. The control section110may control transmission and reception, measurement and so on using the transmitting/receiving section120, the transmitting/receiving antennas130, and the communication path interface140. The control section110may generate data, control information, a sequence and so on to transmit as a signal, and forward the generated items to the transmitting/receiving section120. The control section110may perform call processing (setting up, releasing) for communication channels, manage the state of the base station10, and manage the radio resources.

The transmitting/receiving section120may include a baseband section121, a Radio Frequency (RF) section122, and a measurement section123. The baseband section121may include a transmission processing section1211and a reception processing section1212. The transmitting/receiving section120can be constituted with a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmitting/receiving circuit, or the like described based on general understanding of the technical field to which the present disclosure pertains.

The transmitting/receiving section120may be structured as a transmitting/receiving section in one entity, or may be constituted with a transmitting section and a receiving section. The transmitting section may be constituted with the transmission processing section1211, and the RF section122. The receiving section may be constituted with the reception processing section1212, the RF section122, and the measurement section123.

The transmitting/receiving antennas130can be constituted with antennas, for example, an array antenna, or the like described based on general understanding of the technical field to which the present disclosure pertains.

The transmitting/receiving section120may transmit the above-described downlink channel, synchronization signal, downlink reference signal, and so on. The transmitting/receiving section120may receive the above-described uplink channel, uplink reference signal, and so on.

The transmitting/receiving section120may form at least one of a transmit beam and a receive beam by using digital beam forming (for example, precoding), analog beam forming (for example, phase rotation), and so on.

The transmitting/receiving section120(transmission processing section1211) may perform the processing of the Packet Data Convergence Protocol (PDCP) layer, the processing of the Radio Link Control (RLC) layer (for example, RLC retransmission control), the processing of the Medium Access Control (MAC) layer (for example, HARQ retransmission control), and so on, for example, on data, control information, and so on acquired from the control section110, and may generate bit string to transmit.

The transmitting/receiving section120(transmission processing section1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, discrete Fourier transform (DFT) processing (as necessary), inverse fast Fourier transform (IFFT) processing, precoding, digital-to-analog conversion, and so on, on the bit string to transmit, and output a baseband signal.

The transmitting/receiving section120(RF section122) may perform modulation to a radio frequency band, filtering, amplification, and so on, on the baseband signal, and transmit the signal of the radio frequency band through the transmitting/receiving antennas130.

On the other hand, the transmitting/receiving section120(RF section122) may perform amplification, filtering, demodulation to a baseband signal, and so on, on the signal of the radio frequency band received by the transmitting/receiving antennas130.

The transmitting/receiving section120(reception processing section1212) may apply reception processing such as analog-digital conversion, fast Fourier transform (FFT) processing, inverse discrete Fourier transform (IDFT) processing (as necessary), filtering, de-mapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, the processing of the RLC layer and the processing of the PDCP layer, and so on, on the acquired baseband signal, and acquire user data, and so on.

The transmitting/receiving section120(measurement section123) may perform the measurement related to the received signal. For example, the measurement section123may perform Radio Resource Management (RRM) measurement, Channel State Information (CSI) measurement, and so on, based on the received signal. The measurement section123may measure a received power (for example, Reference Signal Received Power (RSRP)), a received quality (for example, Reference Signal Received Quality (RSRQ), a Signal to Interference plus Noise Ratio (SINR), a Signal to Noise Ratio (SNR)), a signal strength (for example, Received Signal Strength Indicator (RSSI)), channel information (for example, CSI), and so on. The measurement results may be output to the control section110.

The communication path interface140may perform transmission/reception (backhaul signaling) of a signal with an apparatus included in the core network30or other base stations10, and so on, and acquire or transmit user data (user plane data), control plane data, and so on for the user terminal20.

Note that the transmitting section and the receiving section of the base station10in the present disclosure may be constituted with at least one of the transmitting/receiving section120, the transmitting/receiving antennas130, and the communication path interface140.

The transmitting/receiving section120may transmit information indicating two transmission configuration indication (TCI) states for a physical downlink shared channel (PDSCH). The control section110may control transmission of the PDSCH, based on the two TCI states. A first quasi co-location (QCL) parameter in a plurality of QCL parameters included in a specific TCI state in the two TCI states may not be applied to reception of the PDSCH but a second QCL parameter other than the first QCL parameter in the plurality of QCL parameters may be applied to the reception of the PDSCH.

The transmitting/receiving section120may transmit information indicating two transmission configuration indication (TCI) states for a physical downlink control channel (PDCCH). The control section110may control transmission of the PDCCH, based on the two TCI states. A first quasi co-location (QCL) parameter in a plurality of QCL parameters included in a specific TCI state in the two TCI states may not be applied to reception of the PDCCH but a second QCL parameter other than the first QCL parameter in the plurality of QCL parameters may be applied to the reception of the PDCCH.

The transmitting/receiving section120may transmit indication of one or more transmission configuration indication (TCI) states. The control section110may determine whether to apply a single frequency network (SFN) scheme to transmission of a physical downlink shared channel (PDCCH), based on the number of the TCI states.

FIG.17is a diagram to show an example of a structure of the user terminal according to one embodiment. The user terminal20includes a control section210, a transmitting/receiving section220, and transmitting/receiving antennas230. Note that the user terminal20may include one or more control sections210, one or more transmitting/receiving sections220, and one or more transmitting/receiving antennas230.

Note that, the present example primarily shows functional blocks that pertain to characteristic parts of the present embodiment, and it is assumed that the user terminal20may include other functional blocks that are necessary for radio communication as well. Part of the processes of each section described below may be omitted.

The control section210controls the whole of the user terminal20. The control section210can be constituted with a controller, a control circuit, or the like described based on general understanding of the technical field to which the present disclosure pertains.

The control section210may control generation of signals, mapping, and so on. The control section210may control transmission/reception, measurement and so on using the transmitting/receiving section220, and the transmitting/receiving antennas230. The control section210generates data, control information, a sequence and so on to transmit as a signal, and may forward the generated items to the transmitting/receiving section220.

The transmitting/receiving section220may include a baseband section221, an RF section222, and a measurement section223. The baseband section221may include a transmission processing section2211and a reception processing section2212. The transmitting/receiving section220can be constituted with a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmitting/receiving circuit, or the like described based on general understanding of the technical field to which the present disclosure pertains.

The transmitting/receiving section220may be structured as a transmitting/receiving section in one entity, or may be constituted with a transmitting section and a receiving section. The transmitting section may be constituted with the transmission processing section2211, and the RF section222. The receiving section may be constituted with the reception processing section2212, the RF section222, and the measurement section223.

The transmitting/receiving antennas230can be constituted with antennas, for example, an array antenna, or the like described based on general understanding of the technical field to which the present disclosure pertains.

The transmitting/receiving section220may receive the above-described downlink channel, synchronization signal, downlink reference signal, and so on. The transmitting/receiving section220may transmit the above-described uplink channel, uplink reference signal, and so on.

The transmitting/receiving section220may form at least one of a transmit beam and a receive beam by using digital beam forming (for example, precoding), analog beam forming (for example, phase rotation), and so on.

The transmitting/receiving section220(transmission processing section2211) may perform the processing of the PDCP layer, the processing of the RLC layer (for example, RLC retransmission control), the processing of the MAC layer (for example, HARQ retransmission control), and so on, for example, on data and control information and so on acquired from the control section210, and may generate bit string to transmit.

The transmitting/receiving section220(transmission processing section2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (as necessary), IFFT processing, precoding, digital-to-analog conversion, and so on, on the bit string to transmit, and output a baseband signal.

The transmitting/receiving section220(RF section222) may perform modulation to a radio frequency band, filtering, amplification, and so on, on the baseband signal, and transmit the signal of the radio frequency band through the transmitting/receiving antennas230.

On the other hand, the transmitting/receiving section220(RF section222) may perform amplification, filtering, demodulation to a baseband signal, and so on, on the signal of the radio frequency band received by the transmitting/receiving antennas230.

The transmitting/receiving section220(measurement section223) may perform the measurement related to the received signal. For example, the measurement section223may perform RRM measurement, CSI measurement, and so on, based on the received signal. The measurement section223may measure a received power (for example, RSRP), a received quality (for example, RSRQ, SINR, SNR), a signal strength (for example, RSSI), channel information (for example, CSI), and so on. The measurement results may be output to the control section210.

Note that the transmitting section and the receiving section of the user terminal20in the present disclosure may be constituted with at least one of the transmitting/receiving section220and the transmitting/receiving antennas230.

The transmitting/receiving section220may receive information indicating two transmission configuration indication (TCI) states for a physical downlink shared channel (PDSCH). The control section210may not apply a first quasi co-location (QCL) parameter in a plurality of QCL parameters included in a specific TCI state in the two TCI states to reception of the PDSCH but apply a second QCL parameter other than the first QCL parameter in the plurality of QCL parameters to the reception of the PDSCH.

The control section210may determine the specific TCI state, based on one of a fact that a position of the specific TCI state in the two TCI states is defined in a specification, a fact that the position of the specific TCI state in the two TCI states is notified, and a fact that the specific TCI state has a specific QCL type.

The first QCL parameter may include a Doppler shift and Doppler spread.

The control section210may apply the two TCI states to reception of the PDSCH and reception of a physical downlink control channel.

The transmitting/receiving section220may receive information indicating two transmission configuration indication (TCI) states for a physical downlink control channel (PDCCH). The control section210may not apply a first quasi co-location (QCL) parameter in a plurality of QCL parameters included in a specific TCI state in the two TCI states to reception of the PDCCH but apply a second QCL parameter other than the first QCL parameter in the plurality of QCL parameters to the reception of the PDCCH.

The control section210may determine the specific TCI state, based on one of a fact that a position of the specific TCI state in the two TCI states is defined in a specification, a fact that the position of the specific TCI state in the two TCI states is notified, and a fact that the specific TCI state has a specific QCL type.

The first QCL parameter may include a Doppler shift and Doppler spread.

The control section210may apply the two TCI states to reception of the PDCCH and reception of a physical downlink shared channel.

The transmitting/receiving section220may receive indication of one or more transmission configuration indication (TCI) states. The control section210may determine whether to apply a single frequency network (SFN) scheme to reception of a physical downlink shared channel (PDCCH), based on the number of the TCI states.

When the number of the TCI states is 1, the control section may not apply the SFN scheme to reception of the PDCCH, and when the number of the TCI states is 2, the control section may apply the SFN scheme to the reception of the PDCCH.

The indication may be downlink control information.

The transmitting/receiving section220may receive the PDCCH later than a specific timing based on the downlink control information.

Note that in the present disclosure, the words such as an apparatus, a circuit, a device, a section, a unit, and so on can be interchangeably interpreted. The hardware structure of the base station10and the user terminal20may be configured to include one or more of apparatuses shown in the drawings, or may be configured not to include part of apparatuses.

For example, although only one processor1001is shown, a plurality of processors may be provided. Furthermore, processes may be implemented with one processor or may be implemented at the same time, in sequence, or in different manners with two or more processors. Note that the processor1001may be implemented with one or more chips.

The processor1001controls the whole computer by, for example, running an operating system. The processor1001may be configured with a central processing unit (CPU), which includes interfaces with peripheral apparatus, control apparatus, computing apparatus, a register, and so on. For example, at least part of the above-described control section110(210), the transmitting/receiving section120(220), and so on may be implemented by the processor1001.

Furthermore, the processor1001reads programs (program codes), software modules, data, and so on from at least one of the storage1003and the communication apparatus1004, into the memory1002, and executes various processes according to these. As for the programs, programs to allow computers to execute at least part of the operations of the above-described embodiments are used. For example, the control section110(210) may be implemented by control programs that are stored in the memory1002and that operate on the processor1001, and other functional blocks may be implemented likewise.

The storage1003is a computer-readable recording medium, and may be constituted with, for example, at least one of a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (for example, a compact disc (Compact Disc ROM (CD-ROM) and so on), a digital versatile disc, a Blu-ray (registered trademark) disk), a removable disk, a hard disk drive, a smart card, a flash memory device (for example, a card, a stick, and a key drive), a magnetic stripe, a database, a server, and other appropriate storage media. The storage1003may be referred to as “secondary storage apparatus.”

The communication apparatus1004is hardware (transmitting/receiving device) for allowing inter-computer communication via at least one of wired and wireless networks, and may be referred to as, for example, a “network device,” a “network controller,” a “network card,” a “communication module,” and so on. The communication apparatus1004may be configured to include a high frequency switch, a duplexer, a filter, a frequency synthesizer, and so on in order to realize, for example, at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-described transmitting/receiving section120(220), the transmitting/receiving antennas130(230), and so on may be implemented by the communication apparatus1004. In the transmitting/receiving section120(220), the transmitting section120a(220a) and the receiving section120b(220b) can be implemented while being separated physically or logically.

Also, the base station10and the user terminals20may be structured to include hardware such as a microprocessor, a digital signal processor (DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), and so on, and part or all of the functional blocks may be implemented by the hardware. For example, the processor1001may be implemented with at least one of these pieces of hardware.

Here, numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. For example, numerology may indicate at least one of a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a particular filter processing performed by a transceiver in the frequency domain, a particular windowing processing performed by a transceiver in the time domain, and so on.

A bandwidth part (BWP) (which may be referred to as a “fractional bandwidth,” and so on) may represent a subset of contiguous common resource blocks (common RBs) for certain numerology in a certain carrier. Here, a common RB may be specified by an index of the RB based on the common reference point of the carrier. A PRB may be defined by a certain BWP and may be numbered in the BWP.

Also, the information, parameters, and so on described in the present disclosure may be represented in absolute values or in relative values with respect to certain values, or may be represented in another corresponding information. For example, radio resources may be specified by certain indices.

Also, notification of certain information (for example, notification of “being X”) does not necessarily have to be notified explicitly, and can be notified implicitly (by, for example, not notifying this certain information or notifying another piece of information).

At least one of a base station and a mobile station may be referred to as a “transmitting apparatus,” a “receiving apparatus,” a “radio communication apparatus,” and so on. Note that at least one of a base station and a mobile station may be device mounted on a moving object or a moving object itself, and so on. The moving object may be a vehicle (for example, a car, an airplane, and the like), may be a moving object which moves unmanned (for example, a drone, an automatic operation car, and the like), or may be a robot (a manned type or unmanned type). Note that at least one of a base station and a mobile station also includes an apparatus which does not necessarily move during communication operation. For example, at least one of a base station and a mobile station may be an Internet of Things (IoT) device such as a sensor, and the like.

Likewise, the user terminal in the present disclosure may be interpreted as base station. In this case, the base station10may have the functions of the user terminal20described above.

Actions which have been described in the present disclosure to be performed by a base station may, in some cases, be performed by upper nodes. In a network including one or a plurality of network nodes with base stations, it is clear that various operations that are performed to communicate with terminals can be performed by base stations, one or more network nodes (for example, Mobility Management Entities (MMEs), Serving-Gateways (S-GWs), and so on may be possible, but these are not limiting) other than base stations, or combinations of these.

“The maximum transmit power” according to the present disclosure may mean a maximum value of the transmit power, may mean the nominal maximum transmit power (the nominal UE maximum transmit power), or may mean the rated maximum transmit power (the rated UE maximum transmit power).