TRANSFER CONFIGURATION INDICATION (TCI) STATE CHANGE FOR 5G-NR

Abstract

A device (300) in a UE (User Equipment) designed to operate in a 5GS (Fifth Generation System), the device (300) comprising: processing circuitry (306); and memory (308), the processing circuitry (306) being designed to Decoding radio resource control (RRC) signaling to configure the UE with a list of one or more transmission configuration indication (TCI) states for a physical downlink control channel (PDCCH); where each TCI state on the list defines a quasi-colocation (QCL) relationship between downlink reference signals and a port of the DM-RS (demodulation reference signal) of the PDCCH; Decoding a TCI state indication via a Medium Access Control (MAC) Control Element (MAC) CE indicating one of the TCI states on the PDCCH reception activation list for a CORESET (control resource set) of a serving cell; and Demodulating the PDCCH using one of the downlink reference signals based on the QCL relationship for the activated TCI state, wherein the memory (308) is configured to store the TCI states.

Description

TECHNICAL FIELD

[0001] Embodiments relate to cellular communications. Some embodiments relate to transmit configuration indication (TCI) state transitions in 5G (fifth generation) New Radio (NR) systems. BACKGROUND

[0002] In 5G-NR, a Transmit Configuration Indication (TCI) state is used to establish the quasi-colocation (QCL) connection between the destination RS (reference signal) and the source RS. TCI states are configured for the PDCCH (Physical Downlink Control Channel) or a PDSCH (Physical Downlink Shared Channel) to convey the QCL indication for the respective RS. A TCI state change can make it difficult for a UE (User Equipment) to successfully receive the PDCCH or PDSCH with the new TCI state. Thus, TCI state transition procedures are needed to help ensure successful reception of a PDCCH or PDSCH with a new TCI state.

[0003] US 2020 / 0267571 A1 discloses a method for transmitting and receiving data based on quantum computer-based localization in a wireless communication system and a device therefor. This document provides a method for receiving data based on quasi-colocation (QCL) in a wireless communication system.In particular, a data reception method performed by a terminal device comprises the following steps: receiving, from a base station, transmission configuration indication (TCI) status information related to at least one QCL indication related to a downlink reference signal (DL RS) using RRC signaling; receiving a physical downlink control channel (PDCCH) including downlink control information (DCI) in a first time slot from the base station; and receiving a physical downlink shared channel (PDSCH) including data from the base station based on one or more QCL indications. Therefore, the flexibility of the terminal device during beam switching can be improved. SUMMARY OF THE INVENTION

[0004] The present invention is defined by the independent claims. Advantageous embodiments are described in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows TCI states for CORESET (control resource sets) other than CORESET0 according to some embodiments; Fig. 2 shows TCI states for the PDSCH according to some embodiments; and Fig. 3 shows a device according to some embodiments. DETAILED DESCRIPTION

[0005] The following description and drawings illustrate specific embodiments sufficiently to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in or substituted for those of other embodiments. Embodiments recited in the claims include all available equivalents of those claims.

[0006] According to embodiments, a gNB (next-generation Node B) configured for operation in a 5GS (fifth-generation system) encodes signaling for transmission to a UE (user equipment) indicating a transmission configuration indication (TCI) state change to activate a new TCI state. A PDCCH (physical downlink control channel) is encoded according to a highest aggregation level if the signaling indicating the TCI state change indicates activation of a new TCI state for the PDCCH. A PDSCH (physical downlink shared channel) is encoded according to a lowest MCS (modulation and coding scheme) level if the signaling indicating the TCI state change indicates activation of a new TCI state for the PDSCH. After the TCI state change, RS (reference signals) are transmitted by the UE with a different spatial filter or demodulation of the antenna ports of the PDCCH and PDSCH.These embodiments are described in more detail below.

[0007] In 5G NR systems, a transmit configuration indication (TCI) state is used to establish the quasi-colocalization (QCL) connection between the target RS (reference signals) and source RS. Two antenna ports are quasi-colocated if properties of the channel over which a symbol is transmitted on one antenna port can be inferred from the channel over which a symbol is transmitted on the other antenna port. The antenna port QCL types are defined below: type Description QCL-TypeA Doppler shift, Doppler spread, mean delay, delay spread QCL-TypeB Doppler shift, Doppler spread QCL TypeC Doppler shift, mean delay QCL-TypeD Spatial Rx parameter

[0008] TCI states are configured for RSs of PDCCH, PDSCH, and CSI (channel state information) to convey the QCL indication for the respective RSs. QCL types AC are applicable in FR1 (frequency range 1), and QCL types AD are applicable in FR2. QCL type D for FR2 (frequency range 2) indicates that PDCCH / PDSCH / CSI RSs are transmitted with the same spatial filter as the reference signal associated with that TCI. In FR2, the network can indicate a transmit beam change for PDSCH or PDCCH by changing the TCI state.

[0009] As in Fig.As shown in Figure 1, a UE can be configured with a TCI list for PDSCH and PDCCH via RRC. The TCI states for PDCCH are a subset of those for PDSCH. For PDCCH, the network configures the active TCI state via MAC-CE. RRC can configure up to 128 TCI states for PDSCH. Via MAC-CE, the UE can have up to eight activated TCI states, although the scope of the embodiments is not limited in this regard.

[0010] As in Fig.As shown in Figure 2, if the UE can be configured with the higher-layer parameter tci-PresentInDCI set to "enabled" for the CORESET scheduling the PDSCH, the TCI field is present in the Downlink Control Information (DCI) format 1_1. If the scheduling offset between the scheduling and the PDSCH is greater than Threshold-Sched-Offset and the TCI field is present, the TCI state for the PDSCH is indicated via DCI. If tci-PresentInDCI is not configured, or the PDSCH is scheduled using DCI format 1_0, or the scheduling offset between the PDCCH and the PDSCH is less than Threshold-Sched-Offset, the PDSCH follows the TCI of the PDCCH. Threshold-Sched-Offset is based on the UE capability timeDurationForQCL.

[0011] TCI state changes and corresponding beam transitions can be initiated via the MAC-CE or DCI. If the TCI for the PDSCH is specified via DCI, the TCI state or beam transition can be configured via DCI. A DCI-based TCI state transition is applicable to the PDSCH. If the PDSCH follows the TCI state of the PDCCH, for a beam transition, the TCI state of the PDCCH must first be initiated via the MAC-CE. Therefore, a MAC-CE-based TCI state transition would be applicable for the PDCCH.

[0012] When the network activates a new TCI state via MAC-CE for PDCCH or via DCI for PDSCH, the UE is given some time to prepare to receive with the new TCI state. To successfully receive with the new TCI state, the UE must know the Rx beam corresponding to the new TCI state and the time / frequency offset. Furthermore, the network may follow specific procedures to ensure that the UE successfully receives with the new TCI state.

[0013] The network could specify a TCI state change for the PDCCH via MAC-CE and Command, and for the PDSCH via DCI. A known TCI state is defined as a target TCI state to which the UE can transition without performing further Rx beam measurements and / or time / frequency synchronization. The TCI state is defined as known if the UE has reported an L1 RSRP or L3 RSRP measurement to the network within a specified time, such that the measurement performed by the UE is still valid given the mobility and propagation environment. If the target TCI state is known, the UE is not given additional time for Rx beam refinement for the new TCI state and is expected to transition and receive with the new TCI state after the TCI state transition delay.After the TCI state transition command is received by the UE for a known target TCI state, since the UE is expected to transition to the new TCI state without further Rx beam refinement or measurements, the embodiments disclosed herein provide procedures to be followed by the network to enable successful reception at the TCI state.

[0014] According to embodiments, for a MAC-CE-based TCI state transition to a known TCI state, the UE must receive the PDCCH with the new TCI state after the transition delay, without any further Rx beam refinement or measurement for the new TCI state. If the PDCCH is used to schedule the DL-PDSCH with the same TCI state, the UE should be able to subsequently receive the PDSCH with the new TCI state. If the network always transmits with the lowest code rate PDCCH with the maximum aggregation level and the PDSCH with the lowest possible MCS, they can be successfully received with the new TCI state without further beam refinement and based on the Rx beam information from before the measurement.

[0015] According to embodiments, for DCI-based TCI state transitions for the PDSCH to a known TCI state, in order for the UE to successfully receive with the new TCI state after the TCI state transition delay, the PDSCH should be transmitted with the lowest MCS to ensure that it is successfully received with the new TCI state.

[0016] According to embodiments, for MAC-CE-based TCI state transitions, after a TCI state transition delay, the network transmits the PDCCH with the highest aggregation level with the new TCI state. According to embodiments, for MAC-CE-based TCI state transitions for the PDCCH, if the PDCCH is used to schedule the PDSCH, the PDSCH with the lowest MCS is scheduled with the new TCI state. According to embodiments, for DCI-based TCI state transitions for the PDSCH, after the TCI state transition delay, the network transmits the PDSCH with the lowest MCS with the new TCI state.

[0017] According to embodiments, the UE may be configured with a list of up to M TCI state configurations in the higher-layer parameter PDSCH-Config to decode the PDSCH according to a detected PDCCH with DCI determined for the UE and the given serving cell, where M depends on the UE capability maxNumberConfiguredTCIstatesPerCC. Each TCI state contains parameters for configuring a quasi-colocation relationship between one or two downlink reference signals and the DM-RS ports of the PDSCH, the DM-RS port of the PDCCH, or the CSI-RS port(s) of a CSI-RS resource. The quasi-colocation relationship is configured by the higher-layer parameter qcl-Typel for the first DL-RS, and by qcl-Type2 for the second DL-RS (if configured). In the case of two DL-RS, the QCL types should not be the same, regardless of whether the references are to the same DL-RS or different DL-RS.The quasi-colocalization types corresponding to each DL-RS are given by the higher-layer parameter qcl-Type in QCL-Info.

[0018] The UE receives an activation command used to map up to 8 TCI states to the code points of the DCI field 'Transmission Configuration Indication' in a CC / DL BWP (in a set of CC / DL BWPs). When a set of TCI state IDs is activated for a set of CC / DL BWPs, where the applicable list of CCs is determined by the specified CC in the activation command, the same set of TCI state IDs is applied for all DL BWPs in the specified CCs.

[0019] If a UE supports two TCI states in a code point for the 'Transmission Configuration Indication' DCI field, the UE can receive an activation command. The activation command is used to map up to eight combinations of one or two TCI states to the code points of the 'Transmission Configuration Indication' DCI field. The UE is not expected to receive more than eight TCI states in the activation command.

[0020] If the UE would transmit a PUCCH with HARQ-ACK information in slot n corresponding to the PDSCH carrying the activation command, the specified mapping between TCI states and code points of the DCI field ‘Transmission Configuration Indication’ should be applied starting from the first slot following slot n+3Nslotsubframe,μ where u is the SCS configuration for the PUCCH. If tci-PresentInDCI is set to "enabled" or tci-PresentInDCI-ForFormatl_2 is configured for the CORESET scheduling the PDSCH, and the time offset between the reception of the DL-DCI and the corresponding PDSCH is greater than or equal to timeDurationForQCL, if applicable, after a UE receives an initial configuration of higher-layer TCI states and before receiving the activation command, the UE may assume that the DM-RS ports of the PDSCH of a serving cell are quasi-colocated with the SS / PBCH block determined in the initial access procedure with reference to 'QCL-TypeA' and, if applicable, also with reference to 'QCL-TypeD'.

[0021] If a UE can be configured with the higher-layer parameter tci-PresentInDCI set to 'enabled' for the CORESET dividing the PDSCH, the UE assumes that the TCI field is present in DCI format 1_1 of the PDCCH transmitted on the CORESET. If the UE can be configured with a higher-layer parameter tci-PresentInDCI-ForFormatl_2 for the CORESET dividing the PDSCH, the UE assumes that the TCI field is present in DCI format 1_2 of the PDCCH transmitted on the CORESET, with a DCI field size specified by tci-PresentInDCI-ForFormatl_2.If the PDSCH is partitioned by a DCI format where the TCI field is not present, and the time offset between the reception of the DL-DCI and the corresponding PDSCH is greater than or equal to a threshold timeDurationForQCL, if applicable, where the threshold is based on reported UE capability to determine PDSCH antenna port quasi-colocation, the UE assumes that the TCI state or QCL assumption for the PDSCH is identical to the TCI state or QCL assumption, whichever is applied for the CORESET used for the PDCCH transmission.

[0022] If the PDSCH is scheduled by a DCI format where the TCI field is present, the TCI field in DCI in the scheduled component carrier points to the enabled TCI states in the scheduled component carrier or DL-BWP, the UE shall use the TCI state according to the value in the 'Transmission Configuration Indication' field in the detected PDCCH with DCI to determine PDSCH antenna port quasi-colocation. The UE may assume that the DM-RS ports of the PDSCH of a serving cell are quasi-colocated with the RS(es) in the TCI state with respect to the QCL type parameter(s) given by the specified TCI state if the time offset between the reception of the DL-DCI and the corresponding PDSCH is greater than or equal to a threshold timeDurationForQCL, where the threshold is based on reported UE capability [13, TS 38.306].If the UE can be configured with a single-slot PDSCH, the specified TCI state should be based on the enabled TCI states in the slot with the scheduled PDSCH. If the UE can be configured with a multi-slot PDSCH, the specified TCI state should be based on the enabled TCI states in the first slot with the scheduled PDSCH, and the UE should expect the enabled TCI states to be the same across the slots in the scheduled PDSCH.If the UE can be configured with a CORESET associated with a search space set for cross-carrier scheduling, and the PDCCH carrying the scheduling DCI and the PDSCH scheduled by that DCI are transmitted on the same carrier, the UE expects tci_PresentInDCI to be set as 'enabled' or tci_PresentInDCI-ForFormat1_2 to be configured for the CORESET, and if one or more of the TCI states configured for the serving cell scheduled by the search space set contains 'QCL-TypeD', the UE expects the time offset between the reception of the detected PDCCH in the search space set and the corresponding PDSCH to be greater than or equal to the timeDurationForQCL threshold.

[0023] Regardless of the configuration of tci-PresentInDCI and tci-PresentInDCI-ForFormatl_2 in RRC Connected mode, if all TCI code points are mapped to a single TCI state and the offset between the reception of the DL-DCI and the corresponding PDSCH is smaller than the timeDurationForQCL threshold, the UE may assume that the DM-RS ports of the PDSCH of a serving cell are quasi-colocated with the RS(es) with respect to the QCL parameter(s) used to PDCCH quasi-colocate the CORESET associated with a monitored search space with the lowest controlResourceSetId in the last slot in which one or more CORESETs in the active BWP of the serving cell are monitored by the UE. In this case, if the 'QCL-TypeD' of the PDSCH-DM-RS is different from that of the PDCCH-DM-RS with which they overlap in at least one symbol, the UE is expected to prioritize the reception of the PDCCH associated with this CORESET.This also applies to the intra-band CA case (when the PDSCH and the CORESET are located in different component carriers).

[0024] If none of the configured TCI states for the serving cell of the scheduled PDSCH contains 'QCL-TypeD', the UE shall obtain the other QCL assumptions from the specified TCI states for its scheduled PDSCH regardless of the time offset between the reception of the DL-DCI and the corresponding PDSCH. For a UE configured by the higher layer parameter PDCCH-Config containing two different values ​​of CORESETPoolIndex in ControlResourceSet, for both cases when tci-PresentInDCI is set to 'enabled' and tci-PresentInDCI is not configured in RRC-Connected mode, if the offset between the reception of the DL-DCI and the corresponding PDSCH is smaller than the timeDurationForQCL threshold, the UE may assume that the DM-RS ports of the PDSCH associated with a value of CORESETPoolIndex of a serving cell are connected with respect to the PDSCH(s).the QCL parameters used for PDCCH quasi-colocation indication of the CORESET assigned to a monitored search space with the lowest CORESET ID among CORESETS configured with the same value of CORESETPoolIndex as the PDCCH subdividing this PDSCH, in the last slot in which one or more CORESETS assigned to the same value of CORESETPoolIndex as the PDCCH subdividing this PDSCH are quasi-colocated with the RS(es) in the active BWP of the serving cell monitored by the UE.If the offset between the reception of the DL-DCI and the corresponding PDSCH is smaller than the timeDurationForQCL threshold and at least one configured TCI state for the serving cell of the scheduled PDSCH contains the 'QCL-TypeD' and at least one TCI code point indicates two TCI states, the UE may assume that the DM-RS ports of the PDSCH of a serving cell are quasi-colocated with the RS(es) with respect to the QCL parameters associated with the TCI state(s) corresponding to the lowest code point among the TCI code points containing two different TCI states.

[0025] If the PDCCH carrying the scheduling DCI is received on a component carrier and the PDSCH scheduled by this DCI is on a different component carrier: timeDurationForQCL is determined based on the subcarrier spacing of the scheduled PDSCH. In case µ PDCCH <µ PDSCHan additional timing delay d is added to timeDurationForQCL; for both cases that tci-PresentInDCI is set to 'enabled' and the offset between the reception of the DL-DCI and the corresponding PDSCH is smaller than the timeDurationForQCL threshold, and that tci-PresentInDCI is not configured, the UE obtains its QCL acceptance for the scheduled PDSCH from the enabled TCI state with the lowest ID applicable to the PDSCH in the active BWP of the scheduled cell.

[0026] For a periodic CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer parameter trs-Info, the UE shall expect a TCI state to indicate one of the following quasi-colocation types: 'QCL-TypeC' with an SS / PBCH block, and, if applicable, 'QCL-TypeD' with the same SS / PBCH block, or 'QCL-TypeC' with an SS / PBCH block and, if applicable, 'QCL-TypeD' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer parameter repetition, or for an aperiodic CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer parameter trs-Info, the UE shall expect a TCI state 'QCL-TypeA' with a periodic CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher-layer parameter trs-Info and, if applicable, 'QCL-TypeD' with the same periodic CSI-RS resource.

[0027] For a CSI-RS resource in an NZP-CSI-RS ResourceSet configured without the higher layer parameter trs-Info and without the higher layer parameter repetition, the UE shall expect a TCI state to indicate one of the following quasi-colocation types: 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer parameter trs-Info and, if applicable, 'QCL-TypeD' with the same CSI-RS resource, or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer parameter trs-Info and, if applicable, 'QCL-TypeD' with an SS / PBCH block, or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer parameter trs-Info. CSI-RS-ResourceSet and, if applicable, 'QCL-TypeD' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter repetition or ,QCL-TypeB' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher-layer parameter trs-Info, if 'QCL-TypeD' is not applicable.

[0028] For a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer repetition parameter, the UE shall expect a TCI state to indicate one of the following quasi-colocation types: 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer trs-Info parameter and, if applicable, 'QCL-TypeD' with the same CSI-RS resource, or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer trs-Info parameter and, if applicable, 'QCL-TypeD' with a CSI-RS resource in an NZP-CSI-RS ResourceSet configured with the higher layer repetition parameter, or 'QCL-TypeC' with an SS / PBCH block and, if applicable, 'QCL-TypeD' with the same SS / PBCH block.

[0029] For the DM-RS of the PDCCH, the UE shall expect a TCI state to indicate one of the following quasi-colocation types: 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info and, if applicable, 'QCL-TypeD' with the same CSI-RS resource, or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info and, if applicable, 'QCL-TypeD' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter repetition or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured without the higher layer parameter trs-Info and without the higher layer parameter repetition NZP-CSI-RS-ResourceSet and, if applicable, 'QCL-TypeD' with the same CSI-RS resource.

[0030] For the DM-RS of the PDSCH, the UE shall expect a TCI state to indicate one of the following quasi-colocation types: 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info and, if applicable, 'QCL-TypeD' with the same CSI-RS resource, or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info and, if applicable, 'QCL-TypeD' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured with the higher layer parameter repetition or 'QCL-TypeA' with a CSI-RS resource in an NZP-CSI-RS-ResourceSet configured without the higher layer parameter trs-Info and without the higher layer parameter repetition. CSI-RS-ResourceSet and, if applicable, 'QCL-TypeD' with the same CSI-RS resource.

[0031] In some embodiments, the network may enable and disable the configured TCI states for the PDSCH of a serving cell by transmitting the TCI state enable / disable for the UE-specific PDSCH MAC CE. The configured TCI states for the PDSCH are initially disabled upon configuration and after a handover. In these embodiments, when the MAC entity receives a TCI state enable / disable for the UE-specific PDSCH MAC CE on a serving cell, the MAC entity may indicate to lower layers the information regarding the TCI state enable / disable for the UE-specific PDSCH MAC CE.

[0032] In some embodiments, the network may indicate a TCI state for PDCCH reception for a CORESET of a serving cell by transmitting the TCI state indication for UE-specific PDCCH MAC CE. In these embodiments, when the MAC entity receives a TCI state indication for UE-specific PDCCH MAC CE on a serving cell, the MAC entity may indicate the information regarding the TCI state indication for UE-specific PDCCH MAC CE to lower layers.

[0033] According to some embodiments, the UE may signal one or more of the following UE capability parameters: additionalActiveTCI-StatePDCCH - Indicates whether the UE supports an additional active TCI state for control in addition to the supported number of active TCI states for PDSCH. The UE can only include this field if maxNumberActiveTCI-PerBWP in tci-StateDPSCH is set to n1. Otherwise, the UE does not include this field. multipleTCI - Indicates whether the UE supports more than one TCI state configuration per coreset. The UE must track only one active TCI state per coreset. The UE must support a minimum of 64 TCI states and the number of configured TCI states specified by tci-StatePDSCH. This field should be set to supported. SpatialRelations - Indicates whether the UE supports spatial relations. Capability signaling includes the following parameters. - maxNumberConfiguredSpatialRelations specifies the maximum number of configured spatial relations per CC for PUCCH and SRS. Not applicable to FR1 and only to FR2. The UE can report 16 or higher values; - maxNumberActiveSpatialRelations specifies the maximum number of active spatial relations with respect to PUCCH and SRS for PUSCH per BWP per CC. Not applicable to FR1 and only applicable to FR2, and must be reported. - additionalActiveSpatialRelationPUCCH indicates support for an additional active spatial relation for PUCCH. This is mandatory with capability signaling if maxNumberActiveSpatialRelations is set to 1; - maxNumberDL-RS-QCL-TypeD specifies the maximum number of downlink RS resources used for QCL type D in the active TCI states, as well as active spatial relation information, which is optional. - tci-StatePDSCH - Defines support for TCI states for the PDSCH. Capability signaling includes the following parameters: - maxNumberConfiguredTCIstatesPerCC specifies the maximum number of configured TCI states per CC for the PDSCH. For FR2, the UE is required to set this value to 64. For FR1, the UE is required to set these values ​​to the maximum number of allowed SSBs in the supported band; - maxNumberActiveTCI-PerBWP specifies the maximum number of activated TCI states per BWP per CC, including control and data. If a UE reports X active TCI states, no more than X active QCL Type-D acceptances for any PDSCH and any CORESETs for a given BWP of a serving cell are expected to become active for the UE. The UE shall include this field.

[0034] In these embodiments, the UE only needs to track the active TCI states. In some embodiments, the following RRC fields may be used for RRC signaling. ControlResourceSet field descriptions

[0035] tei-PresentInDCI - This field indicates whether the TCI field is present or absent in the DL-related DCI. If the field is absent, the UE considers the TCI absent / disabled. In the case of cross-carrier scheduling, the network sets this field to enabled for the ControlResourceSet used for cross-carrier scheduling in the scheduling cell.

[0036] tei-StatesPDCCH-ToAddList - A subset of the TCI states defined in pdsch-Config contained in the BWP-DownlinkDedicated corresponding to the serving cell and the DL-BWP to which the ControlResourceSet belongs. They are used to provide QCL relationships between the DL-RS in an RS set (TCI state) and the PDCCH DMRS ports. The network configures at most maxNrofTCI-StatesPDCCH entries. CSI-AssociatedReportConfigInfo field descriptions

[0037] qcl-info - List of references to TCI states to provide the QCL source and QCL type for each NZP-CSI-RS resource listed in nzp-CSI-RS-Resources of the NZP-CSI-RS-ResourceSet specified by NZP-CSI-RS-ResourcesforChannel. Each TCI state ID refers to the TCI state that has this value for tci-StateId and is defined in tci-StatesToAddModList in the PDSCH Config contained in the BWP downlink corresponding to the serving cell and the DL-BWP to which resourcesForChannelMeasurement (in the CSI ReportConjig specified by reportConfigID above) belongs. NZP-CSI-RS resource field descriptions

[0038] qcl-InfoPeriodicCSI-RS - For a target periodic CSI-RS, contains a reference to a TCI state in TCI-States to provide the CQL source and QCL type. For periodic CSI-RS, the source can be SSB or another periodic CSI-RS. Refers to the TCI state that has this value for tci-StateId and is defined in tci-StatesToAddModList in the PDSCH-Config contained in the BWP downlink corresponding to the serving cell and the DL-BWP to which the resource belongs.

[0039] PDSCH-Config - The PDSCH-Config IE is used to configure the UE-specific PDSCH parameters.

[0040] tci-StatesToAddModList - A list of Transmission Configuration Indicator (TCI) states, specifying a transmission configuration that includes QCL relationships between the DL-RSs in an RS set and the PDSCH DMRS ports.

[0041] Fig.3 shows a device according to some embodiments. Device 300 may be suitable for use as a mobile device, such as a UE, or suitable for use as a base station, such as a gNB (Next Generation Node B). Device 300 may include at least processing circuitry 306 and memory 308. Processing circuitry 306 may include a baseband processor and may implement, among other things, a PHY (Physical Layer) 302 and a Medium Access Control (MAC) layer 304.

[0042] In some embodiments, the gNB may be configured for operation in a 5GS (fifth generation system). In these embodiments, the processing circuitry may be configured to encode signaling for transmission to a UE (user equipment), the signaling indicating a transmission configuration indication (TCI) state change to activate a new TCI state, encode a PDCCH (physical downlink control channel) for transmission to the UE according to a highest aggregation level if the signaling indicating the TCI state change indicates activation of a new TCI state for the PDCCH, and encode a PDSCH (physical downlink shared channel) for transmission to the UE according to a lowest modulation and coding scheme (MCS) level if the signaling indicating the TCI state change indicates activation of a new TCI state for the PDSCH.After the TCI state change, the processing circuitry may configure the gNB for transmission of RS (reference signals) with a different spatial filter or different antenna ports. The RS is used for demodulation of the PDCCH and PDSCH by the UE. In these embodiments, a different spatial filter may be used for FR2. Different antenna ports may be used for FR1 and FR2. The memory may be configured to store TCI states for the PDCCH and for the PDSCH. In these embodiments, the gNB may retain the lowest MCS level for the PDSCH and / or the highest aggregation level for the PDCCH until CQI feedback is received from the UE.

[0043] In some embodiments, the processing circuitry may be configured to determine whether the new TCI state is a known TCI state or an unknown TCI state. In these embodiments, a known TCI state includes a TCI state in which the gNB has received an L1 (Layer 1) RSRP (Reference Signal Received Power) measurement report or an L3 (Layer 3) RSRP measurement report for the new TCI state from the UE within a predetermined time.

[0044] In some embodiments, the processing circuitry may be further configured to encode radio resource control (RRC) signaling for configuring the UE with a list of one or more TCI states for decoding the PDCCH and one or more TCI states for decoding the PDSCH. In these embodiments, the TCI states for the PDCCH may be a subset of the TCI states for the PDSCH, and the new TCI state is a TCI state on the list. In these embodiments, each TCI state on the list includes parameters for configuring a quasi-colocation (QCL) relationship between one or two downlink reference signals and demodulation reference signal (DM-RS) ports of the PDSCH, or a DM-RS port of the PDCCH, or a CSI-RS port(s) of a CSI-RS resource.

[0045] In some embodiments, the signaling indicating the TCI state change for the PDCCH may include a MAC-CE (Medium Access Control (MAC) Control Element) indicating a change to the new TCI for the PDCCH. In these embodiments, the gNB may transmit the PDCCH according to the highest aggregation level to help ensure that the UE can successfully receive the PDCCH with the new TCI state.

[0046] In some embodiments, the signaling indicating the TCI state change for the PDCCH includes a MAC-CE (Medium Access Control (MAC) Control Element) indicating a change to the new TCI for a PDCCH scheduling the PDSCH, and the processing circuitry may be configured to encode the scheduled PDSCH according to the lowest MCS. In these embodiments, the gNB may transmit the PDSCH scheduled by the PDCCH according to the lowest MCS to help ensure that the UE can successfully receive the PDCCH with the new TCI state.

[0047] In some embodiments, the signaling indicating the TCI state change includes DCI (Downlink Control Information) and indicates activation of a new TCI state for the PDSCH. In these embodiments, the gNB may transmit the PDSCH according to the lowest MCS to help ensure that the UE can successfully receive the PDCCH with the new TCI state.

[0048] In some embodiments, the processing circuitry may be configured to encode the PDCCH or the PDSCH for transmission to the UE after a handoff delay. In these embodiments, the handoff delay may be based at least in part on whether the new TCI state is a known TCI state or an unknown TCI state.

[0049] In some embodiments, the handover delay may be longer when the new TCI state is an unknown TCI state, and the handover delay may be shorter when the new TCI state is a known TCI state. In these embodiments, the handover delay allows time for the UE to begin receiving with a new TCI state and to allow additional time for the UE to perform beam refinement when the TCI state is unknown.

[0050] In some embodiments, after transitioning to the new TCI state and transmitting the PDSCH, the processing circuitry is further configured to decode CSI (channel state information) received from the UE based on reference signals associated with the new TCI state for the PDSCH, determine a new MCS based on the CSI, indicate the new MCS to the UE for use in decoding the PDSCH, and encode the PDSCH according to a new MSC for transmission to the UE.

[0051] In some embodiments, a non-transitory computer-readable storage medium storing instructions for execution by the processing circuitry of the gNB configured for operation in a 5GS (fifth generation system).

[0052] In some embodiments, the UE may be configured for operation in a 5GS, and the processing circuitry may be configured to decode signaling from a gNB indicating a transmission configuration indication (TCI) state change activation of a new TCI state, decode a PDCCH (Physical Downlink Control Channel) according to a highest aggregation level if the signaling indicating the TCI state change indicates activation of a new TCI state for the PDCCH, and decode a PDSCH (Physical Downlink Shared Channel) according to an indicated modulation and coding scheme (MCS) level. In these embodiments, the indicated MCS level is a lowest MCS level if the signaling indicating the TCI state change indicates activation of a new TCI state for the PDSCH. The memory may be configured to store TCI states for the PDCCH and for the PDSCH.

[0053] In these embodiments, the UE may perform blind decoding of a number of PDCCH candidates based on a PDCCH search space for PDCCH acquisition specified in a SIB (System Information Block). The UE may perform blind decoding on all possible combinations of the aggregation level for the PDCCH, depending on the CORESET configuration. In these embodiments, the UE decodes the PDCCH and / or the PDSCH based on reference signals used for demodulation (i.e., DM-RS). The reference signals are associated with the TCI state. The MCS level used to decode the PDSCH may be specified by the gNB as the lowest MCS level when a new TCI state is activated.

[0054] In some embodiments, if the new TCI state for the PDCCH is an unknown TCI state for the PDCCH, the processing circuitry is to configure the UE to perform receive beam refinement before decoding the PDCCH with the new TCI state. In these embodiments, if the new TCI state for the PDCCH is a known TCI state for the PDCCH, the processing circuitry may be configured to omit configuring the UE to perform receive beam refinement before decoding the PDCCH with the new TCI state. In these embodiments, if the new TCI state for the PDSCH is an unknown TCI state for the PDSCH, the processing circuitry is to configure the UE to perform beam refinement before decoding the PDSCH with the new TCI state.In these embodiments, if the new TCI state for the PDSCH is a known TCI state for the PDSCH, the processing circuitry should refrain from configuring the UE to perform receive beam refinement before decoding the PDSCH with the new TCI state. In these embodiments, the UE does not need to perform additional receive beam refinement before decoding the PDCCH / PDSCH with a known TCI state. The TCI state indicates the QCL type and antenna ports. On the other hand, the UE may need to perform additional receive beam refinement before decoding the PDCCH / PDSCH with an unknown TCI state.

[0055] In some embodiments, in response to the signaling indicating the TCI state change, the processing circuitry may be configured to determine whether the new TCI state is a known TCI state or an unknown TCI state. In these embodiments, a known TCI state includes a TCI state in which the UE has sent an L1 (Layer 1) RSRP (Reference Signal Received Power) measurement report or an L3 (Layer 3) RSRP measurement report for the TCI state to the gNB within a predetermined time.

[0056] In some embodiments, the UE may be configured via radio resource control (RRC) signaling with a list of one or more TCI states for decoding the PDCCH and one or more TCI states for decoding the PDSCH, where the TCI states for the PDCCH are a subset of the TCI states for the PDSCH. In these embodiments, each TCI state on the list includes parameters for configuring a quasi-colocation (QCL) relationship between one or two downlink reference signals and demodulation reference signal (DM-RS) ports of the PDSCH, or a DM-RS port of the PDCCH, or a CSI-RS port(s) of a CSI-RS resource.

[0057] In some embodiments, after switching to the new TCI and decoding the PDSCH, the UE is further configured to encode CSI (Channel State Information) for transmission to the gNB, wherein the CSI comprises a PMI, a CQI, and RI for the PDSCH based on reference signals associated with the new TCI for the PDSCH, receive an indication of a new MCS for decoding the PDSCH, and decode the PDSCH according to a new MCS, wherein the new MCS is determined by the gNB based on the CSI.

[0058] In some embodiments, the mobile device may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless phone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or another device capable of wirelessly receiving and / or transmitting information. In some embodiments, the mobile device may include one or more of the following: a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touchscreen.

[0059] The antennas ( Fig. 3) may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmitting RF signals. In some multiple-input, multiple-output (MIMO) embodiments, the antennas may be effectively separated to exploit spatial diversity and the different channel characteristics that may arise.

[0060] Although the mobile device is illustrated with multiple separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including DSPs (digital signal processors) and / or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, FPGAs (field-programmable gate arrays), ASICs (application-specific integrated circuits), RFICs (radio frequency integrated circuits), and combinations of various hardware and logic circuits for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.

[0061] Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device that can be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). A computer-readable storage device may include, for example, ROM (read-only memory), RAM (random access memory), magnetic disk storage media, optical storage media, flash memory devices, and other storage devices and media.Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

Claims

[1] A device (300) in a UE (User Equipment) designed to operate in a 5GS (Fifth Generation System), the device (300) comprising: processing circuitry (306); and memory (308), the processing circuitry (306) being designed to Decoding radio resource control (RRC) signaling to configure the UE with a list of one or more transmission configuration indication (TCI) states for a physical downlink control channel (PDCCH); where each TCI state on the list defines a quasi-colocation (QCL) relationship between downlink reference signals and a port of the DM-RS (demodulation reference signal) of the PDCCH; Decoding a TCI state indication via a Medium Access Control (MAC) Control Element (MAC) CE indicating one of the TCI states on the PDCCH reception activation list for a CORESET (control resource set) of a serving cell; and Demodulating the PDCCH using one of the downlink reference signals based on the QCL relationship for the activated TCI state, wherein the memory (308) is configured to store the TCI states. [2] The apparatus (300) of claim 1, wherein the RRC signaling comprises a CORESET IE (Information Element) for configuring the UE with the list of one or more TCI states for the PDCCH. [3] The apparatus (300) of claim 2, wherein the processing circuitry (306) is configured to apply spatial relation information to the downlink reference signal according to the QCL relationship configured by the activated TCI state for demodulating the PDCCH. [4] The apparatus (300) of claim 1, wherein for a PDSCH (Physical Downlink Shared Channel) partitioned by the PDCCH, the processing circuitry (306) is to demodulate the PDSCH based on the activated TCI of the PDCCH for a period of time according to a parameter timeDurationForQCL. [5] The apparatus (300) of claim 4, wherein the RRC signaling further comprises information for configuring the UE with a list of one or more TCI states for the PDSCH, wherein the TCI states for the PDCCH are a subset of the TCI states for the PDSCH, and each TCI state for the PDSCH defines a QCL relationship between downlink reference signals and DM-RS ports of the PDSCH. [6] The apparatus (300) of claim 5, wherein the processing circuitry (306) is configured to decode a TCI state indication via a second MAC-CE indicating one of the TCI states on the list for activation for the PDSCH of the serving cell. [7] The apparatus (300) of claim 1, wherein the processing circuitry (306) is configured to decode the PDCCH based on the asserted TCI after an assertion delay, wherein the assertion delay is based at least in part on whether the asserted TCI state is a known TCI state or an unknown TCI state. [8] The apparatus (300) of claim 7, wherein the processing circuitry (306) is configured to determine whether the activated TCI state is a known TCI state or an unknown TCI state, wherein a known TCI state includes a TCI state in which the UE has provided an L1 RSRP measurement report of the L1 (Layer 1) RSRP (Reference Signal Received Power) or an L3 RSRP measurement report of the L3 (Layer 3) RSRP for the activated TCI state. [9] The apparatus (300) of claim 4, wherein the processing circuitry (306) is configured to initially decode the scheduled PDSCH according to the lowest MCS (Modulation and Coding Scheme) after a TCI state change. [10] The apparatus (300) of claim 4, wherein the processing circuitry (306) is configured to decode the PDCCH according to a highest aggregation level when the MAC-CE indicates activation of a new TCI state for the PDCCH. [11] A non-transitory computer-readable storage medium storing instructions for execution by processing circuitry (306) of a UE (User Equipment) configured to operate in a 5GS (Fifth Generation System), the instructions directing the processing circuitry (306) to: Decoding radio resource control (RRC) signaling to configure the UE with a list of one or more transmission configuration indication (TCI) states for a physical downlink control channel (PDCCH); where each TCI state on the list defines a quasi-colocation (QCL) relationship between downlink reference signals and a port of the DM-RS (demodulation reference signal) of the PDCCH; Decoding a TCI state indication via a Medium Access Control (MAC) control element (CE) indicating one of the TCI states on the PDCCH receive enable list for a CORESET (control resource set) of a serving cell; and Demodulate the PDCCH using one of the downlink reference signals based on the QCL relationship for the enabled TCI state. [12] The non-transitory computer-readable storage medium of claim 11, wherein the RRC signaling comprises a CORESET IE (Information Element) for configuring the UE with the list of one or more TCI states for the PDCCH. [13] The non-transitory computer-readable storage medium of claim 12, wherein the processing circuitry (306) is configured to apply spatial relation information to the downlink reference signal according to the QCL relationship configured by the activated TCI state for demodulating the PDCCH. [14] The non-transitory computer-readable storage medium of claim 13, wherein for a PDSCH (Physical Downlink Shared Channel) partitioned by the PDCCH, the processing circuitry (306) is to demodulate the PDSCH based on the activated TCI of the PDCCH for a period of time according to a parameter timeDurationForQCL. [15] The non-transitory computer-readable storage medium of claim 14, wherein the RRC signaling further comprises information for configuring the UE with a list of one or more TCI states for the PDSCH, wherein the TCI states for the PDCCH are a subset of the TCI states for the PDSCH, and each TCI state for the PDSCH defines a QCL relationship between downlink reference signals and DM-RS ports of the PDSCH. [16] The non-transitory computer-readable storage medium of claim 15, wherein the processing circuitry (306) is configured to decode a TCI state indication via a second MAC-CE indicating one of the TCI states on the list for activation for the PDSCH of the serving cell. [17] The non-transitory computer-readable storage medium of claim 11, wherein the processing circuitry (306) is configured to decode the PDCCH based on the asserted TCI after an assertion delay, wherein the assertion delay is based at least in part on whether the asserted TCI state is a known TCI state or an unknown TCI state. [18] A device (300) for a gNB (Node B of a Generation) designed to operate in a 5GS (Fifth Generation System), the device (300) comprising: Processing circuitry (306); and memory (308), wherein the processing circuitry (306) is configured to encode radio resource control (RRC) signaling for configuring a UE (user equipment) with a list of one or more transmission configuration indication (TCI) states for a PDCCH (physical downlink control channel); where each TCI state on the list defines a quasi-colocation (QCL) relationship between downlink reference signals and a port of the DM-RS (demodulation reference signal) of the PDCCH; Encoding a TCI state indication via a Medium Access Control (MAC) control element (CE) for transmission to the UE, wherein the MAC CE indicates one of the TCI states on the PDCCH reception activation list for a CORESET (control resource set) of a serving cell; and Causing the gNB to transmit the PDCCH using one of the downlink reference signals based on the QCL relationship for the enabled TCI state, wherein the memory (308) is configured to store the TCI states. [19] The apparatus (300) of claim 18, wherein the processing circuitry (306) of the gNB is configured to encode the RRC signaling to include a CORESET IE (information element) for configuring the UE with the list of one or more TCI states for the PDCCH. [20] The apparatus (300) of claim 19, wherein for a PDSCH (Physical Downlink Shared Channel) partitioned by the PDCCH, the processing circuitry (306) is to cause the gNB to modulate the PDSCH based on the activated TCI of the PDCCH for a period of time according to a parameter timeDurationForQCL.

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